CN1776830A - Signal transmission cable and method for manufacturing signal transmission cable - Google Patents

Abstract

A signal transmission cable comprises dielectric core layers extending along the longitudinal direction of the cable; a first conductive layer which is layered on an outer surface of the dielectric core layers; a second conductive layer which is layered on the other outer surface of the dielectric core layers; and insulating material for covering the dielectric core layers and the first and second layers. Each and all of the dielectric core layers and the first and second layers have the same width, and each of the first and second layers has the same thickness. The insulating material is covered with a shield layer, and the shield layer is covered with a sheath, wherein the first and second layers form a pair of differential signal lines.

Description

Signal transmission cable and method for manufacturing signal transmission cable

technical field

The invention relates to a signal transmission cable and a method for manufacturing the signal transmission cable, in particular to a signal transmission cable capable of high-speed transmission of high-reliability differential signals.

Background technique

In recent years, the high frequency of information equipment represented by network equipment and personal computers has been progressing extremely rapidly, and the clock pulse frequency has reached the region exceeding GHz. Along with this, there is an increasing demand for high-speed data transmission in signal transmission cables connected between devices. In addition, with the increase in the speed of signal transmission, the number of signal lines increases with the increase in data capacity, and the demand for high-speed multi-core cables is also very high.

Fig. 40 shows an example of the structure of a conventional flexible multi-core cable. As shown in FIG. 40, on the insulating film 1000, a plurality of center conductors 1001 for transmitting signals are arranged in parallel, and then the center conductors 1001 are covered with an insulating film 1002, thereby forming a microstrip structure.

In addition, FIG. 41A, FIG. 41B shows the structure example of the conventional multi-core coaxial cable. As shown in FIG. 41B , the multi-core coaxial cable has a plurality of thin coaxial cables 1110 , and after the plurality of thin coaxial cables 1110 are arranged in parallel, the entirety is covered with an insulating film 1115 . As shown in FIG. 41A , a thin-wire coaxial cable 1110 covers a central conductor 1111 for transmitting signals with an insulating film 1112 , and further covers its outer periphery with an outer conductor 1113 and an insulating film 1114 serving as a ground plane.

The flexible multi-core cable shown in FIG. 40 can be manufactured cheaply because of its simple structure, but since the central conductor 1001 is not completely shielded, it is easily affected by external noise and it is difficult to prevent deterioration of signal transmission quality.

The multicore coaxial cable shown in FIG. 41A has high noise resistance, but is expensive due to its complicated structure.

In Japanese Patent Document (Japanese Laid-Open No. 2003-323824 ), related technology is disclosed regarding a method of manufacturing a multi-core coaxial cable that solves such a problem. 42A to 42D are diagrams showing a method of manufacturing a multi-core coaxial cable disclosed in this patent document. As shown in FIG. 42A, after preparing the first insulating film 1121 with outer conductors 1120, 1122' formed on both sides, the upper outer conductors 1122' (outer conductors 1122' are not shown) are etched to uniformly form a plurality of outer conductors arranged at a certain interval. Signal line 1122. Next, as shown in FIG. 42B , first insulating films 1121 in which signal lines 1122 are collectively formed are stacked in multiple stages with second insulating films 1123 interposed therebetween, and after stacking outer conductors 1124 at the uppermost stage, the layers are crimped. Then, as shown in FIG. 42C , the manufactured laminate is divided longitudinally by a slicer, thereby cutting out many multi-core coaxial cables 1130 . Finally, as shown in FIG. 42D, on the side of the multi-core coaxial cable 1130 cut out, an outer conductor 1131 is formed. The outer conductor 1131 is in contact with the inner outer conductor 1120 of the multi-core coaxial cable 1130 on the side of the cable, and is connected to each other. This completes the multicore coaxial cable.

After adopting the manufacturing method shown in Fig. 42A-Fig. 42D, since many multi-core coaxial cables can be cut out uniformly, it can be manufactured cheaply, and it becomes the center conductor of the signal line, and adopts a structure completely covered by the outer conductor, so in While having high noise resistance, it can also prevent crosstalk between transmission lines.

However, although the multi-core coaxial cable formed by the manufacturing method shown in FIGS. 42A to 42D has excellent noise resistance, it is difficult to completely eliminate the influence of external noise. In addition, although it has excellent noise resistance, when the signal transmission speed exceeds the GHz region, external noise becomes an important factor that reduces the reliability of the transmission signal, so in high-speed transmission, even multi-core coaxial cables, Measures against extraneous noise must also be taken.

The differential signal transmission method is widely known as a transmission method that is highly resistant to external noise. This method uses a pair of signal lines to send signals with opposite phases to each other, and after obtaining the difference, it cancels the external noise, so in principle, no external noise can be generated.

FIG. 43 shows the basic structure of a conventional differential signal transmission cable 1200 . As shown in FIG. 43 , on the outer periphery of an inner wire 1201 composed of twisted wires of many conductor wire bundles, two signal wires with an insulating layer 1202 are arranged in parallel. It surrounds the outer conductor 1203 serving as a shielding layer, and further surrounds the outer periphery thereof with a sheath 1204 made of an insulating material. In addition, in order to give a ground potential to the outer conductor 1203 serving as the shield layer, a drain line 1205 is provided so as to be in contact with the outer conductor 1203 along the signal line of the twin wire. As prior art related to transmission of differential signals using such a pair of wires, for example, it is described in the following Japanese Patent Documents.

Special Opening No. 2001-093357

Special Opening No. 2002-358841

Special Opening No. 2004-087198

On the other hand, with the increase of signal lines, a cable in which many differential signal lines (two-core signal lines) are paralleled has been realized. FIG. 44 shows an example of a tape-shaped multi-core differential signal transmission cable 1210 in which many differential signal lines are arranged in parallel to form an integral structure. It is called "dual strip line". A pair of differential transmission lines formed by conductive wiring 1211 and 1212 formed opposite to each other are buried in parallel in the dielectric layer 1213, and shielding layers are formed on both sides of the dielectric layer 1213. 1214, 1215. If a flexible film is used for the dielectric layer, a flexible differential signal transmission cable (ribbon cable) can be constructed.

In addition, in FIG. 44 , an example of a dual-strip line in which a pair of conductive wiring lines are vertically matched is described as a differential signal line. However, a so-called "microstrip line" structure in which a pair of conductive wiring lines are arranged laterally may also be employed. As prior art related to differential signal transmission using such a multi-core flat cable, it is described in the following Japanese patent documents.

Special Opening No. 2001-210959

Special Opening No. 2002-158452

45A-45E show a method of manufacturing the differential signal transmission cable shown in FIG. 44 . In FIG. 45A, materials for forming conductive foils 1214, 1221 on both sides of a dielectric sheet 1220 are prepared. As shown in FIG. Next, as shown in FIG. 45C, after forming a dielectric layer 1222 and a conductive foil 1223 on the entire surface of the dielectric sheet 1220, a pattern is etched on the conductive foil 1223 to form a large number of conductive wirings 1212 as shown in FIG. At this time, the conductive wiring 1212 is aligned at a position facing the conductive wiring 1211 and is formed to have the same width as the conductive wiring 1211 . In this way, a pair of differential transmission lines having the same characteristic impedance is formed. Finally, as shown in FIG. 45E, a dielectric layer 1223 and a conductive foil 1225 are formed on the entire surface of the dielectric sheet 1220, thereby completing the differential transmission process of embedding many differential transmission lines in the dielectric (the dielectric sheet 1220 and the dielectric layers 1222, 1223). moving signal transmission cable.

Although the differential signal transmission method has strong anti-interference characteristics. However, in order to transmit differential signals at a higher speed, it is necessary to take measures to make the characteristic impedance of the two-core signal lines of the differential signal transmission cable equal, or to take measures to reduce skew (difference in propagation delay time).

In the differential signal transmission cable 1200 shown in FIG. 43, a pair of inner conductors 1201 serving as twin wires are constituted by twisted wires of a plurality of conductor bundles. However, when the conductor wire bundles are twisted, a difference in tension often occurs between the two wire bundles. Therefore, a dispersion occurs in the physical length of the two-core signal line that becomes a pair of wires, and this causes an increase in time lag.

In addition, as shown in FIG. 43 , although the leakage line 1205 is in contact with the insulating layer 1202 covering the outer circumference of a pair of inner conductors 1201 that become twinned lines, when the twinned lines and the leaky line 1205 are surrounded by the outer conductor 1203, After the leakage line 1205 is firmly in contact with the external conductor 1203, the leakage line cuts into the insulating layer 1202, which tends to cause the insulating layer 1202 to be damaged. Therefore, a capacity dispersion occurs between the two-core signal lines of the differential signal transmission cable, and this becomes a cause of characteristic impedance imbalance.

In order to solve this problem, for example, as described in Japanese Patent Application Laid-Open No. 2004-087198, an interposer is provided between a pair of twin wires covering inner conductor 1201 with insulating layer 1202 and leakage line 1205 . However, since the distance between the paired wire and the leaky wire 1205 varies with the shape of the intervening object, it cannot be kept constant inside the transmission cable 1200, and a new problem of characteristic impedance imbalance arises, making it difficult to manufacture highly reliable differential signal transmission. cable.

On the other hand, in the multi-core differential signal transmission cable 1210 shown in FIG. It is formed after matching with another conductive wiring 1211, so alignment dispersion is easy to occur. As a result, these manufacturing variations cause the characteristic impedance of the differential signal transmission cable to be unbalanced. In addition, although manufacturing dispersion can be suppressed by improving processing accuracy, the introduction of high-precision processing equipment will inevitably increase manufacturing costs. In addition, for long-distance cables, the improvement of processing accuracy is also limited.

To sum up, in the prior art differential signal transmission cables, there are problems such as dispersion of characteristic impedance and time lag. These problems lead to malfunctions caused by degradation of signal transmission, and are an important cause of hindering speed-up of differential signal transmission. In addition, although the multi-core simultaneous cable formed by the manufacturing method shown in Fig. 42A-Fig. 42C has a ribbon structure, the cut part shown in Fig. 42C is changed to include two signal lines arranged side by side along the sheet plane direction. After the location, it is also possible to form a multi-core differential transmission cable in units of a pair of signal lines constituting a differential signal transmission line.

However, in the multi-core differential transmission cable formed in this way, since a pair of signal lines are formed by etching, dispersion tends to occur in the width of the signal lines and the interval between the signal lines. Since these values are parameters for determining the characteristic impedance of the differential signal transmission cable, the manufacturing dispersion of these values directly affects the dispersion of the characteristic impedance of the differential signal transmission cable. The dispersion of the characteristic impedance brings about the malfunction caused by the deterioration of the signal transmission, and becomes an important factor hindering the speed-up of the differential signal transmission.

In addition, when signal lines formed on different layers (that is, layers with different vertical directions such as the upper layer and the lower layer) are used as a pair of signal lines to form a differential signal transmission line, it is difficult to connect a pair of signal lines between different layers. The line is correctly aligned, and positional deviation is easy to occur.

After the above-mentioned position shift occurs, it directly affects the dispersion of the characteristic impedance of the differential signal transmission cable. As a result, the dispersion of the characteristic impedance brings about malfunctions caused by the degradation of signal transmission, and becomes an important factor hindering the speed-up of differential signal transmission.

Contents of the invention

A main object of the present invention is to provide a high-reliability differential signal transmission cable that produces less dispersion or time lag in characteristic impedance.

In order to solve the above-mentioned problems, the signal transmission cable of the present invention has: a dielectric core layer extending along the length direction of the cable, a first conductive layer laminated on one surface of the dielectric core layer, and a The second conductive layer stacked on the other side covers the dielectric core layer and the insulator of the first and second conductive layers, covers the conductive shielding layer of the insulator, and then covers the insulating layer of the conductive shielding layer. Sexual skin. The dielectric core layer and the first and second conductive layers have the same width as each other. The first and second conductive layers have the same thickness as each other.

After adopting the above-mentioned structure, the transmission core cable composed of three layers such as the first conductive layer, the dielectric core layer and the second conductive layer can make each parameter (thickness of each layer, thickness of each layer, etc.) Width, interval) values are the same, so it is possible to realize a highly reliable signal transmission cable without characteristic impedance dispersion.

Preferably, the first conductive layer and the second conductive layer constitute a pair of differential signal lines.

In addition, when the first dielectric layer is laminated on the first conductive layer, the first ground conductive layer is also laminated on the first dielectric layer; when the second dielectric layer is laminated on the second conductive layer, , also stacking a second grounding conductive layer on the second dielectric layer; the first dielectric layer, the first grounding conductive layer, the second dielectric layer and the second grounding conductive layer, and The dielectric core layer, the first conductive layer, and the second conductive layer have the same width; the first dielectric layer and the second dielectric layer preferably have the same thickness.

Furthermore, the thickness of the dielectric core layer is preferably thinner than the thickness of the first and second dielectric layers.

Furthermore, there are a plurality of said transmission core cables, preferably contained by said insulator.

In addition, it is preferable to provide a conductive film for grounding on the other surface of the dielectric sheet.

In addition, the dielectric core layer is preferably composed of any one of polyimide, wholly aromatic polyamide, polyethylene terephthalate, polydiphenyl sulfide, and liquid crystal polymer.

In addition, it is preferable that the colors and shapes of the surfaces of the first conductive layer and the second conductive layer are different.

In addition, the thickness of the end portion in the cable length direction of the transmission core cable is preferably thicker than the thickness of other cable regions.

The method for manufacturing a signal transmission cable of the present invention includes: a step of preparing a dielectric core sheet having a sheet length equal to or greater than the cable length and a sheet width equal to or greater than several times the cable width; on both sides of the dielectric core sheet, A process of laminating conductor sheets to cover both sides; a process of dividing (cutting) the dielectric core sheet by a cable width to simultaneously form a plurality of transmission core cables; enclosing each of the plurality of transmission core cables with an insulator process.

In addition, it is preferable to further include a step of removing residues of the dielectric core sheet remaining on the divided surfaces of the transmission core cables after dividing the dielectric core sheet to form a plurality of transmission core cables.

Another method of manufacturing a signal transmission cable of the present invention includes: a step of preparing a dielectric core sheet having a sheet length equal to or greater than the cable length and a sheet width equal to or greater than several times the cable width; A step of stacking conductor sheets on both sides to cover the two sides; a step of stacking dielectric sheets on the conductor sheets to cover the conductor sheets;

A process of laminating conductor sheets for grounding on the conductor sheet to cover the dielectric sheet; dividing the dielectric core sheet by the cable width to simultaneously form a plurality of transmission core cables; enclosing the plurality of transmission core cables with an insulator Each process of the core cable.

After adopting the above-mentioned signal transmission cable of the present invention and its manufacturing method, since each parameter of the characteristic impedance of the transmission core cable (each layer's of each layer) that is made of 3 layers such as the 1st conductive layer, the dielectric core layer and the 2nd conductive layer can be made Thickness, width, interval) have the same value, so it is possible to realize a highly reliable signal transmission cable without characteristic impedance dispersion. In addition, since the transmission core cable forms three layers of the first conductive layer, the dielectric core layer, and the second conductive layer, multiple transmission core cables are formed at the same time by collectively cutting, so it is possible to produce uniform transmission with a high yield rate. core cable. By making the color or shape of the surface of the first conductive layer and the second conductive layer different, it is possible to easily distinguish whether each terminal is the first or second conductive layer at both ends of the transmission cable of the present invention. Which of the. Thus, the present invention can provide a highly reliable signal transmission cable. In addition, the same effects can be obtained even if the colors and shapes of the surfaces of the first and second dielectric layers are changed.

The manufacturing method of the multi-core differential transmission cable of the present invention includes: laminating the first ones respectively having a length dimension equal to or greater than the dimension in the length direction of the cable and a width dimension equal to or greater than several times the dimension in the width direction of the cable in the following order: A step of forming a laminated body sheet from the conductor sheet, the first dielectric sheet, and the second conductor sheet; a step of sequentially stacking a plurality of the laminated sheets with the second dielectric sheet interposed therebetween to form a long-sized sheet; A step of rolling a long sheet into a roll; a step of dividing while pulling out the end of the sheet from the long sheet rolled into a roll.

With the above-mentioned structure, by collectively dividing the laminate sheet composed of the first conductor sheet, the first dielectric sheet, and the second conductor sheet, the line width of a pair of signal lines constituting the differential transmission line (cut The width of the first and second conductor sheets) and the interval between the signal lines (thickness of the first dielectric sheet) are formed to be consistent. Therefore, the dispersion of the characteristic impedance of the differential transmission line can be reduced. In addition, since the long-sized sheets in which the laminated sheets constituting the differential transmission lines are stacked are collectively divided, it is also possible to reduce variations in the width of the signal lines and the spacing between the signal lines between the stacked plurality of differential transmission lines. Therefore, a multi-core differential transmission cable with uniform characteristic impedance can be realized.

In addition, as a step before dividing the elongated sheet, a step of rolling the elongated sheet into a roll is included; the step before dividing the elongated sheet is preferably pulled from the elongated sheet rolled into a roll. Cut out the ends of the slices, splitting aside.

The multi-core differential transmission cable of the present invention has a first conductor sheet, a first dielectric sheet, and a second conductor sheet each having a length dimension equal to the dimension in the length direction of the cable and a width dimension equal to the dimension in the width direction of the cable, which are stacked in the following order. A laminated body sheet formed after body sheeting. The first conductor sheet and the second conductor sheet have the same thickness. In the laminate sheet, a third dielectric sheet and a third conductor sheet are laminated on the surface of at least one of the first and second conductor sheets in the following order. A plurality of the laminate sheets are sequentially stacked with the second dielectric sheet interposed therebetween. The first conductive sheet and the second conductive sheet constitute a pair of differential transmission lines arranged to sandwich the first dielectric sheet. The third conductor piece constitutes a ground line.

In addition, a connector is provided at the end of the cable, and the connector preferably has a thick portion in which the thickness of the second dielectric sheet is thicker than that of other thin sheet portions. In this case, it is preferable to expose the first and second conductor sheets by removing a part of the second dielectric sheet in the thick portion.

According to the multi-core differential transmission cable and the manufacturing method thereof according to the present invention, the laminated body sheet composed of the first conductor sheet, the first dielectric sheet, and the second conductor sheet can be collectively divided, thereby making it possible to configure the differential transmission cable. The line width of a pair of signal lines (the width of the cut first and second conductor sheets) and the interval between the signal lines (the thickness of the first dielectric sheet) of the circuit are formed to be uniform. Therefore, the dispersion of the characteristic impedance of the differential transmission line can be reduced. In addition, since the long-sized sheets in which the laminated sheets constituting the differential transmission lines are stacked are collectively divided, it is also possible to reduce variations in the width of the signal lines and the spacing between the signal lines between the stacked plurality of differential transmission lines. Therefore, a multi-core differential transmission cable with uniform characteristic impedance can be realized.

Furthermore, by collectively dividing the elongated sheets on which the laminated sheets are stacked, a plurality of multi-core differential transmission cables can be manufactured simultaneously, so that an inexpensive multi-core differential transmission cable can be realized.

The manufacturing method of the flexible differential transmission cable of the present invention includes: a step of forming a first conductive film on a flexible dielectric sheet; a step of forming a dielectric film on the first conductive film; Above, the process of forming the second conductive film; after cutting the second conductive film, the dielectric film and the first conductive film, while forming a plurality of strip-shaped grooves in parallel on the dielectric sheet, adjacent The process of forming a differential transmission line composed of a laminate of the second conductive film, the dielectric film, and the first conductive film separated by the groove between the grooves; After the differential transmission line, an insulator is buried in the groove. The groove portions are formed to have the same width, and the differential transmission line is formed of the stacked bodies having the same width.

In addition, it is preferable to further include a step of covering the groove portion embedded in the insulator and the differential transmission line with an insulating layer.

In addition, in the method of manufacturing the flexible differential transmission cable of the present invention, it is preferable to further include the step of forming a ground layer on the insulating layer.

In addition, in the method of manufacturing the flexible differential transmission cable of the present invention, it is preferable to further include the step of forming a ground layer on the back surface of the dielectric sheet.

In addition, in the method of manufacturing a flexible differential transmission cable according to the present invention, it is preferable that the second conductive film, the dielectric film, and the first conductive film are cut halfway in the thickness direction so that the first conductive film 1. A portion of the conductive film is left to form a strip-shaped groove, and then the remaining portion of the first conductive film is removed by etching, and the groove is formed.

The manufacturing method of the flexible differential transmission cable of the present invention is formed by cutting the first conductive film, the dielectric film and the second conductive film formed on the dielectric sheet in the state where the dielectric sheet remains, and then forming the strip-shaped groove portion , so that a plurality of differential transmission lines composed of a laminate of the first conductive film, the dielectric film, and the second conductive film separated from each other by the groove can be formed simultaneously in the state of being integrated with the dielectric sheet, and production can be realized. High efficiency flexible differential transmission cables.

In addition, after the first conductive film, the dielectric film, and the second conductive film are cut at the same time on the basis of lamination, since the differential transmission line composed of the laminate of the first conductive film, the dielectric film, and the second conductive film can be determined Therefore, the line width of a pair of signal lines constituting the differential transmission line (the width of the cut first and second conductive films), the distance between the signal lines (that is, the distance between the first and second conductive films) The distance, in other words, the thickness of the dielectric film) and the position of the signal line (the alignment of the first and second conductive films) are formed in a consistent manner. In this way, the dispersion of the characteristic impedance of the differential transmission line can be reduced, and a highly reliable flexible differential transmission cable can be realized.

Furthermore, by forming the laminates constituting the differential transmission line with the same width and the same interval, a multi-core differential transmission cable with uniform characteristic impedance can be realized, and a flexible differential transmission cable corresponding to an increase in data capacity can be realized. .

Therefore, according to the present invention, it is possible to provide a method of manufacturing a flexible differential transmission cable with a small dispersion of characteristic impedance and high production efficiency.

The method for manufacturing a signal transmission cable according to the present invention includes: while fabricating a laminated body sheet after alternately laminating conductor sheets and insulator sheets; The sheet end of the laminate sheet and the sheet end of the insulator sheet are arranged in a stepwise manner on the side of the other sheet surface closer to the sheet end. The first step of forming a stepped surface on one sheet surface; the second step of bringing a resin member into contact with the other sheet surface of the sheet end of the laminate sheet; pressing the resin along the thickness direction of the sheet The member deforms the end of the sheet so that the stepped surface and the one sheet surface become the same surface, and the conductor sheet is exposed from the stepped surface that is the same surface as the one sheet surface. Each constitutes the third step of the electrode terminals.

In addition, as the resin member, when the resin member is brought into contact with the other sheet surface, the other side of the resin member that is located on the opposite side of the resin member in contact with the other sheet surface is used. In the third step, it is preferable to deform the end of the sheet so that the other surface of the resin member and the laminated body sheet The other sheet side becomes the same side.

In addition, the resin member is formed of a semi-hardened resin, and after the third step, it is preferable to further include a step of curing the resin member and then integrating the resin member and the laminated body sheet.

In addition, as the resin member, it is preferable to use a material having a size that is in contact with the entire surface of the laminate sheet.

In addition, in the third step, preferably, the resin member is pressed in a sheet thickness direction with a flat plate and the one sheet surface of the sheet end of the laminate sheet.

The manufacturing method of the signal transmission cable of the present invention can form the signal line having high density while also setting the electrode terminal for taking out the signal line of each conductor piece on the exposed surface, so that it can be easily combined with other cables. Terminal connections to circuit boards, etc.

Furthermore, since the terminals of each signal line can be arranged in the same plane as the surface of the laminate sheet, conventional connectors can be used for terminal connection and other circuit boards, etc., and the cost can be reduced. .

According to this aspect, it is possible to provide a signal transmission cable capable of connecting a plurality of circuit boards and the like at high density.

Other objects of the present invention will be apparent after understanding the embodiments described later, and are set forth in the appended claims. Moreover, there are many benefits not mentioned in this specification, after practicing the present invention, those skilled in the art will realize.

Description of drawings

FIG. 1 is a diagram showing the structure of a signal transmission cable according to a first embodiment of the present invention.

2A to 2D are diagrams showing a method of manufacturing the signal transmission cable according to the first embodiment.

Fig. 3 is a diagram showing the configuration of another signal transmission cable according to the first embodiment.

Fig. 4 is a diagram showing the configuration of another signal transmission cable according to the first embodiment.

Fig. 5 is a diagram showing the configuration of another signal transmission cable according to the second embodiment of the present invention.

6A to 6D are diagrams showing a method of manufacturing the signal transmission cable according to the second embodiment.

Fig. 7 is a diagram showing the structure of a signal transmission cable according to a third embodiment of the present invention.

Fig. 8 is a diagram showing the configuration of another signal transmission cable according to the third embodiment.

9A to 9E are diagrams showing a method of manufacturing a signal transmission cable according to a fourth embodiment of the present invention.

10A and 10B are diagrams showing another method of manufacturing a signal transmission cable according to the fourth embodiment.

Fig. 11 is a diagram showing the configuration of a transmission core cable according to a fifth embodiment of the present invention.

12 is a diagram showing a configuration of a connector of a signal transmission cable according to a fifth embodiment.

Fig. 13 The first example of the shape of the first and second conductive layers.

14A and 14B are the second examples of the shapes of the first and second conductive layers.

15A and 15B are diagrams showing a method of manufacturing a multi-core differential transmission cable according to a sixth embodiment of the present invention.

Fig. 16 is a diagram showing a method of cutting a long sheet according to a sixth embodiment of the present invention.

17A is a cross-sectional view of a multi-core differential transmission cable according to a sixth embodiment.

17B is a partially enlarged view of a multi-core differential transmission cable according to a sixth embodiment.

18A and 18B are diagrams showing a shield structure of a signal transmission cable according to a sixth embodiment.

Fig. 19 is a diagram showing a method of cutting a roll-shaped long sheet according to a sixth embodiment.

Fig. 20 is a diagram showing another cutting method of the roll-shaped long sheet according to the sixth embodiment.

Fig. 21 is a cross-sectional view showing the structure of another elongated sheet according to the sixth embodiment.

Fig. 22 is a cross-sectional view showing another structure of another elongated sheet according to the sixth embodiment.

23A and 23B are diagrams showing a method of forming a connector of a multi-core differential transmission cable according to a sixth embodiment.

24A and 24B are enlarged views showing a connector structure of a multi-core differential transmission cable according to a sixth embodiment.

25A to 25D are process cross-sectional views in a direction perpendicular to the cable longitudinal direction showing a method of manufacturing a flexible differential transmission cable according to a seventh embodiment of the present invention.

Fig. 26 is a diagram showing a method of cutting a groove portion according to the seventh embodiment.

27 is a cross-sectional view showing the structure of a shielded flexible differential transmission cable according to a seventh embodiment.

28A to 28D are process cross-sectional views showing another method of manufacturing a flexible differential transmission cable according to the seventh embodiment.

29 is a cross-sectional view showing the structure of a flexible differential transmission cable formed by the manufacturing method of FIGS. 28A to 28D and then planarized.

FIG. 30 is a plan view showing the configuration of a reference example of a flexible signal transmission cable 700 .

31A is a perspective view showing the structure of a signal transmission cable in which electrode terminals are formed stepwise according to an eighth embodiment of the present invention.

Fig. 31B is a cross-sectional view of Fig. 31A.

32A and 32B are cross-sectional views showing a method of flattening a stepped electrode terminal.

33A to 33C are process cross-sectional views showing a method of manufacturing a signal transmission cable according to an eighth embodiment.

Fig. 34 is a plan view showing a signal transmission cable according to an eighth embodiment.

Fig. 35 is a plan view showing another signal transmission cable according to the eighth embodiment.

36A and 36B are process cross-sectional views showing another method of manufacturing a signal transmission cable according to the eighth embodiment.

37A and 37B are cross-sectional views showing the arrangement of electrode terminals of a signal transmission cable according to an eighth embodiment.

FIG. 38 is a diagram showing a configuration when the signal transmission cable according to the eighth embodiment is used for connection between circuit boards.

Fig. 39 is a diagram showing a method of manufacturing a signal transmission cable according to an eighth embodiment.

Fig. 40 is a diagram showing a structural example of a conventional flexible multi-core cable.

41A and 41B are diagrams showing structural examples of conventional multi-core coaxial cables.

42A-42D are diagrams showing a prior art method of manufacturing a multi-core coaxial cable.

Fig. 43 is a diagram showing the structure of a conventional signal transmission cable.

Fig. 44 is a diagram showing the structure of a conventional multi-core signal transmission cable.

45A-45E are diagrams showing a conventional method of manufacturing a multi-core signal transmission cable.

Detailed ways

Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, in order to simplify description, the same reference numerals are used to denote components having substantially the same functions. In addition, this invention is not limited to the following embodiment.

(first embodiment)

FIG. 1 is a schematic cross-sectional view showing the structure of a signal transmission cable 100 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing steps of a method of manufacturing the signal transmission cable 100 according to the first embodiment.

Signal transmission cable 100, as shown in FIG. 1, has: a dielectric core layer 10 extending along the length direction of the cable (direction perpendicular to the drawing); 11 and the second conductive layer 12 form an integrated transmission core cable 20; and an insulator 13 containing the transmission core cable 20.

The first conductive layer 11 and the second conductive layer 12 have the same thickness; the dielectric core layer 10 , the first conductive layer 11 and the second conductive layer 12 have the same width. In addition, the insulator 13 containing the transmission core cable 20 is covered with a shield layer 14 made of a conductor, and the shield layer 14 is covered with a sheath 15 made of an insulator. A pair of differential signal lines is constituted by the first conductive layer 11 and the second conductive layer 12 .

The characteristic impedance of a pair of differential signal lines depends on the width of the first and second conductive layers 11 and 12 and the distance between the first and second conductive layers 11 and 12 . Therefore, the dimensions of the first and second conductive layers 11 and 12 are determined so as to obtain a predetermined characteristic impedance. For example: if make the 1st and the 2nd conductive layer 11,12 by copper, its width is 150 μ m, the distance between the 1st and the 2nd conductive layer 11, 12 is 190 μ m, the dielectric constant of dielectric core layer 10 is 0.4, a characteristic impedance of about 100Ω can be obtained.

Next, a method of manufacturing the signal transmission cable 100 according to the first embodiment will be described with reference to FIG. 2 . First, as shown in Fig. 2A, a dielectric core layer 10' is prepared. Here, as the dielectric core layer 10', an adhesive having a thickness of about 45 µm was formed on both sides of a polyimide sheet having a thickness of about 100 µm. Here, the dielectric core sheet 10' has a rectangular flat plate shape with the direction perpendicular to the drawing in FIG. 2A being the longitudinal direction and the left-right direction of the drawing being the width direction. Furthermore, the dielectric core sheet 10' has a sheet length equal to the cable length of the transmission core cable 20 in its longitudinal direction, and a shape in a width direction equal to or larger than several times the cable width of the transmission core cable 20.

Then, as shown in Fig. 2B, first to second conductor sheets 11', 12' are stacked on the entire surfaces of both surfaces of the dielectric core sheet 10'. Here, first and second conductor sheets 11', 12' made of rolled copper foil with a thickness of about 8 µm were prepared. These first and second conductor sheets 11', 12' are laminated on both surfaces of the dielectric core sheet 10', respectively, by crimping them. At this time, only the surface of the first conductor sheet 11' is colored with a dye. Alternatively, the surface of the first conductor sheet 11' is processed into a rough surface. In this way, the surface state of the first conductor sheet 11' is visually different from the surface state of the second conductor sheet 12'.

Next, as shown in Fig. 2C, the dielectric core sheet 10' having the conductor sheets 11', 12' formed on both sides is cut along the sheet length direction according to the cable width (for example, 150 µm). In order to enable such cutting, the width of the dielectric core sheet 10' is set to be equal to or several times larger than the above-mentioned cable width.

In this way, a plurality of transmission core cables 20 continuous in the longitudinal direction are formed while having the same width dimension (for example, 150 μm). The formed transmission core cable 20 has a three-layer structure material having a first conductive layer 11 , a dielectric core layer 10 and a second conductive layer 12 .

In addition, although the division is performed using a slicer, since the copper foils used as the first and second conductive layers 11 and 12 are very flexible, residues of the copper foil may be left on the division surfaces of the transmission core cable 20 . Since the dielectric core sheet 10' is very thin, the residue of the copper foil becomes an important cause of short-circuiting the pair of differential signal lines. Therefore, after the division, it is a preferable measure to prevent the decline of the yield of products by setting up a process of removing residues. For example, if immersion etching is performed with a solution for etching copper, the above-mentioned residue can be removed without affecting the shape of the divided copper foil. In addition, if laser cutting is used instead of dividing by a microtome, the occurrence of the above-mentioned residue can be suppressed.

Finally, as shown in FIG. 2D , after covering the entire circumference of the cut transmission core cable 20 with an insulator 13 with a thickness of about 500 μm, then cover the insulator 13 with a shielding layer 14 with a thickness of about 50 μm, and then cover the shield with a sheath 15 Layer 14. In this way, the manufacture of the transmission core cable 20 is completed.

Here, as the insulator 13, for example, a fluorine-based resin such as FEP (tetrafluoroethylene-hexafluoropropylene heteropolymer resin), an amorphous polyolefin resin, PEN (polyphthalate), or the like is used. In order to lower the dielectric constant, it is preferable to adopt a foamed shape containing a blowing agent. As the shield layer 14, a metal tape or metal foil having excellent conductivity such as copper or aluminum, or a metal layered film obtained by layering them with a plastic film, or the like can be used. In addition, as the sheath 15, polyvinyl chloride, polyolefin, or the like can be used.

In the signal transmission cable 100 formed by this manufacturing method, the width of the first conductive layer 11 and the width of the second conductive layer 12 constituting the differential signal line can be made to match each other without performing a special width adjustment process. In addition, since the dielectric core layer 10 having a certain thickness is inserted between the first and second conductive layers 11 and 12, the distance between the two conductive layers 11 and 12 can be kept at the full length without any special width adjustment process. become mutually consistent structures.

For the above reasons, the characteristic impedance of the signal transmission cable 100 can be kept at a constant value with high precision along the length direction of the cable. In this way, the balance of the characteristic impedance of the signal transmission cable 100 can be maintained.

In addition, since the signal transmission cable 100 is formed by dividing a single dielectric core sheet 10 ′ whose both ends in the longitudinal direction are aligned, the cable physical length of the signal transmission cable 100 cut out from the same dielectric core sheet 10 ′ is By being consistent with each other, the occurrence of skew (difference in propagation delay time) can also be suppressed between these cables.

Furthermore, since many signal transmission cables 100 are simultaneously formed from the same dielectric core sheet 10', the dispersion of the respective impedance characteristics can be suppressed to a small degree, so that it can be manufactured with a high yield in mass production. Signal transmission cable.

In addition, in the above description, the specific material of each component of a signal transmission cable was illustrated. However, it is not particularly limited thereto. For example, for the dielectric core layer 10, wholly aromatic polyamide, polyethylene terephthalate, polydiphenyl sulfide, liquid crystal polymer, etc. can also be used. In addition, the first and second conductive layers 11 and 12 may be alloys containing copper or other metals.

The signal transmission cable 100 shown in FIG. 1 shows the basic structure of the present invention. However, in actual use, it is very effective to shield the transmission core cable 20 from the outside. FIG. 3 shows an example of the structure of a signal transmission cable 110 having a shielding effect.

In FIG. 3 , the transmission core cable 20 has the same structure as that of FIG. 1 . However, the entire periphery of the transmission core cable 20 is covered with the insulating layer 30 . Furthermore, a leak line 31 is arranged between the insulating layer 30 and the shield layer 14 . The leakage line 31 is set to have the same length as the signal transmission cable 100 . In this way, after the leakage line 31 is connected to the ground potential outside the cable, the shielding layer 14 can be connected to the ground potential through the leakage line 31 . Furthermore, in order to improve electrical connectivity between the leak line 31 and the shield layer 14 , the leak line 31 is pressed into a gap arranged between the insulating layer 30 and the shield layer 14 .

However, the leakage line 31 is pressed into the gap arranged between the insulating layer 30 and the shield layer 14 with a crimping force that does not damage the dielectric core layer 10 between the first and second conductive layers 11 and 12 . Therefore, the provision of the leakage line 31 does not cause the deformation of the dielectric core layer 10 or the imbalance of the characteristic impedance.

In addition, since the signal transmission cable 100 has very small dispersion of characteristic impedance among signal transmission cables, it is also suitable for a multi-core signal transmission cable used when transmitting a plurality of signals in parallel.

FIG. 4 shows an example of the structure of a multi-core signal transmission cable 120 in which many transmission core cables 20 are assembled. In FIG. 4 , a plurality of transmission core cables 20 are covered with an insulating layer 13 in a state of being arranged in parallel with each other. Furthermore, the peripheral surface of the insulating layer 13 is covered with the shield layer 14 and the sheath 15 . In addition, although FIG. 4 shows an example in which two transmission core cables 20 are arranged in parallel, the number of transmission core cables 20 arranged in parallel may be increased or decreased according to the number of signals to be transmitted in parallel. In addition, the transmission core cables 20 can be not only arranged in parallel (arranged in the cable width direction) but also arranged in a column (arranged in the cable thickness direction), and are covered with the insulating layer 13 .

(second embodiment)

Although the differential signal line has strong anti-external noise characteristics, it cannot completely eliminate the external noise. In order to transmit differential signals more stably, it is preferable to adopt a structure in which the transmission core cable 20 is covered with the shield layer 14 . However, as shown in FIG. 3 , in order to apply the ground potential to the shield layer 14 , it is necessary to separately arrange a leak line 31 and connect the shield layer 14 to the ground potential through the leak line 31 . Such a configuration requires an additional configuration, which complicates the manufacturing process and increases the manufacturing cost.

FIG. 5 shows the structure of a signal transmission cable 130 according to a second embodiment of the present invention. In the second embodiment, the shielding effect of the differential signal lines can be obtained without adding leakage lines. That is, the first and second conductive layers 11 and 12 constituting a pair of differential signal lines are arranged facing each other, and the dielectric core layer 10 is inserted between the two conductive layers 11 and 12 . These structures are basically the same as those of the transmission core cable 20 in the first embodiment.

On the upper surface of the first conductive layer 11 , the first dielectric layer 16 is stacked, and the upper surface of the first conductive layer 11 is covered with the first dielectric layer 16 . Furthermore, a first ground conductive layer 18 is laminated on the upper surface of the first dielectric layer 16 , and the upper surface of the first dielectric layer 16 is covered with the first ground conductive layer 18 . Similarly, the second dielectric layer 17 is laminated on the upper surface of the second conductive layer 12 , and the upper surface of the second conductive layer 12 is covered with the second dielectric layer 17 . Furthermore, on the upper surface of the second dielectric layer 17 , a second ground conductive layer 19 is stacked, and the upper surface of the second dielectric layer 17 is covered with the second ground conductive layer 19 .

The first and second dielectric layers 16, 17 have the same thickness as each other. In addition, the first and second dielectric layers 16, 17 and the first and second grounding conductive layers 18, 19 have the same thickness as the dielectric core layer 10, respectively. , The first and second conductive layers 11, 12 have the same width.

Thus, in the second embodiment, the second ground conductive layer 19, the second dielectric layer 17, the second conductive layer 12, the dielectric core layer 10, the first conductive layer 11, and the The shapes of the first dielectric layer 16 and the first ground conductive layer 18 constitute the transmission core cable 21 .

The characteristic impedance of the pair of differential signal lines having the structure shown in FIG. 5 is affected by the width of the first and second conductive layers 11 and 12 and the distance between the first and second conductive layers 11 and 12 . In addition, the above-mentioned characteristic impedance is also affected by the distance between the first or second conductive layers 11 and 12 and the first and second ground conductive layers 18 and 19 . After adjusting them, the above-mentioned characteristic impedance can be specified. Therefore, in the transmission core cable 21, the dimensions of the above-mentioned components are set so as to obtain a desired characteristic impedance.

For example, at this time, the dielectric core layer 10 is made of a polyimide sheet, the first and second conductive layers 11, 12 are made of rolled copper foil, and the first and second dielectric layers 16, 17 are made of a polyimide sheet. After the first and second grounding conductive layers 18 and 19 are made of rolled copper foil, the width of the first and second conductive layers 11 and 12 is 135 μm, and the distance between the first and second conductive layers 11 and 12 is 190 μm, and the distance between the first or second conductive layers 11 and 12 and the first or second ground conductive layers 18 and 19 is 250 μm. In this way, a characteristic impedance of about 100Ω is obtained.

With the above structure, since both surfaces of the pair of differential signal lines 11, 12 are covered with the ground layers 18, 19, the shielding effect can be more effectively imparted to these differential signal lines. In addition, at this time, since the two ground layers 18, 19 can be directly connected to the ground potential outside the cable, there is no need to separately arrange a leakage line, thereby simplifying the structure accordingly.

In addition, the thickness of the dielectric core layer 10 is thinner than that of the first and second dielectric layers 16, 17, so that the connection of the differential signal lines is strengthened, and the signal quality is also improved.

Next, a method of manufacturing the signal transmission cable 130 according to the second embodiment will be described with reference to FIGS. 6A to 6D .

First, as shown in Fig. 6A, a material for laminating the first and second conductor sheets 11', 12' on both surfaces of the dielectric core layer 10' is prepared. Here, as the dielectric core layer 10', an adhesive having a thickness of about 45 µm was formed on both sides of a polyimide sheet having a thickness of about 100 µm. Here, the dielectric core sheet 10' has a rectangular flat plate shape with the thickness direction of the drawing in FIG. 6A being the longitudinal direction and the left-right direction of the drawing being the width direction. Furthermore, the dielectric core sheet 10' has a shape whose longitudinal direction is the sheet length equal to the cable length, and whose width is several times the cable width.

First and second conductor sheets 11', 12' are stacked on the entire surfaces of both sides of the dielectric core sheet 10' to cover the dielectric core sheet 10'. Here, the first and second conductor sheets 11' and 12' made of rolled copper foil with a thickness of about 8 μm are prepared, and these first and second conductor sheets 11' and 12' are crimped to form Dielectric core sheets 10' are stacked on both sides. At this time, only the surface of the first conductor sheet 11' is colored with a dye.

Then, as shown in Fig. 6B, the first and second dielectric sheets 16', 17' are stacked on the entire upper surfaces of the first and second conductor sheets 11', 12'. Furthermore, the first and second ground sheets 18', 19' are stacked on the entire upper surfaces of the first and second dielectric sheets 16', 17'. The first and second dielectric sheets 16', 17' are made of polyimide film with a thickness of about 170 µm; the first and second ground sheets 18', 19' are made of rolled copper foil with a thickness of about 8 µm.

The dielectric core sheets 10' to be laminated are divided according to the cable width along the sheet length direction as shown in Fig. 6C. In this way, a plurality of transmission core cables 21 having the same cable width are formed simultaneously.

The thickness of the formed transmission core cable 21 was about 570 μm. If it is this thickness, it can be easily divided by a common slicer (not shown). In addition, as described in the manufacturing process shown in FIG. 2 , copper foil residues often remain on the split surfaces of the transmission core cables 21 . Therefore, it is preferable to provide a step of removing residues after division.

Finally, as shown in FIG. 6D , the insulator 13 is used to contain the cut-out transmission core cable 21 , and if necessary, cover it with the sheath 15 , and the manufacture of the signal transmission cable 130 is completed. As the insulator 13, PEN containing a foaming agent is used; for the sheath 15, polyvinyl chloride is used.

(third embodiment)

7 and 8 show structures of signal transmission cables 140 and 150 according to a third embodiment of the present invention.

FIG. 7 is a material constituting a so-called multi-core ribbon cable in which a plurality of transmission core cables 20 are assembled. It has one dielectric sheet 40, and on one surface of the dielectric sheet 40, a plurality of transmission core cables 20 are arranged in parallel at substantially equal intervals. (Same structure as described in the first embodiment). On the other side of the dielectric sheet 40, an insulator 41 covering the transmission core cable 20 is laminated. In addition, in order to arrange the transmission core cables 20 , the dielectric sheet 40 has a longitudinal dimension equal to the cable length dimension of the transmission core cables 20 and a width dimension for arranging a plurality of transmission core cables 20 in parallel.

The dielectric sheet 40 uses a material that forms an adhesive of about 75 μm on both sides of a polyimide sheet with a thickness of about 150 μm, and adopts a layering process to heat the insulator 41 composed of PEN mixed with a foaming agent. Sheet 40 is crimped.

In the transmission core cable 20 produced by the manufacturing process described with reference to FIG. 2, the widths of the first and second conductive layers 11 and 12 constituting a pair of differential signal lines are uniformly formed. Since the thickness of the dielectric core layer 10 inserted between the conductive layers 11 and 12 is also constant, the inherent characteristic impedance of the differential signal line can maintain a constant value along the transmission core cable 20 . In addition, since the cable ends of the transmission core cable 20 are also collectively cut in the state of the dielectric core sheet 10', the physical length of the cable can be uniformly formed, and the occurrence of time lag is also suppressed. Furthermore, since a plurality of transmission core cables 20 are simultaneously formed from a single dielectric core sheet 10', the dispersion of the characteristic impedance of each transmission core cable 20 is also small. Therefore, the multi-core signal transmission cable of the present embodiment, in which a plurality of transmission core cables 20 manufactured in this way are arranged in parallel, becomes a highly reliable product with uniform characteristic impedance. Thus, the structure of the present invention is suitable for a signal transmission cable for high-speed parallel transmission.

FIG. 8 is a diagram showing the structure of the signal transmission cable 150 in which the signal transmission cable 140 shown in FIG. 7 has a shielding effect.

As shown in FIG. 8, the signal transmission cable 150 has the same cable structure as the signal transmission cable 140, and then, on both sides (the outer surface of the insulating sheet 41 and the outer surface of the dielectric sheet 40) of the cable structure (signal transmission cable 140) ( On the other surface )), conductive films 42 and 43 for grounding are respectively formed on the entire surface. Furthermore, the respective outer surfaces of the conductive films 42 and 43 for grounding are covered with skins 44 and 45 .

When the conductive films 42 and 43 for ground are connected to the ground potential, these conductive films 42 and 43 for ground function as shielding layers. Here, since the conductive films 42 and 43 for grounding are kept at a certain distance and arranged above and below (both sides in the cable thickness direction) of the transmission core cables 20 arranged in parallel, stable shielding can be exerted for the transmission core cables 20. Effect.

In addition, in the above description, the conductive films 42 and 43 for grounding are provided on both surfaces of the dielectric sheet 40 to obtain a sufficient shielding effect. However, if a conductive film for grounding is arranged at least on the other side of the insulating sheet 41 where the transmission core cable 20 is not laminated, a shielding effect can be obtained.

(fourth embodiment)

Next, a method of manufacturing a signal transmission cable according to a fourth embodiment of the present invention will be described with reference to FIGS. 9A-9E , 10A, and 10B.

9A to 9E are process cross-sectional views illustrating a method of manufacturing the signal transmission cable 160 . First, as shown in Fig. 9A, a material for laminating the first and second conductor sheets 11', 12' on both surfaces of the dielectric core layer 10' is prepared.

Next, as shown in FIG. 9B , the dielectric core layer 10' is divided into a certain width (cable width) along the length direction of the sheet (direction perpendicular to the paper surface). In this way, while having the same cable width, many transmission core cables 20 having a three-layer structure of the first conductive layer 11, the dielectric core layer 10, and the second conductive layer 12 are simultaneously formed. The structure of the transmission core cable 20 and its manufacturing method are the same as those described in the first embodiment.

Next, as shown in FIG. 9C , prepare a sheet-sized first dielectric sheet 50 having a plurality of transmission core cables 20 that can be placed and arranged side by side, and place the transmission core cables 20 at certain intervals, and arrange them side by side on the first sheet. On the dielectric sheet 50.

Then, as shown in FIG. 9D , prepare a second dielectric sheet 51 with the same size as the first dielectric sheet 50, and place the second dielectric sheet 51 on the upper side of the transmission core cable 20 (not with the first dielectric sheet). 50 contiguous faces). In this way, the plurality of transmission core cables 20 are covered with the second dielectric sheet 51 . Furthermore, the first and second dielectric sheets 50 and 51 are divided in the direction of the arrow (thickness direction of the transmission core cable 20). At this time, the division is made along the cable length direction of the transmission core cables 20 , and the division position is defined as a position where there is no cable between adjacent transmission core cables 20 .

Finally, as shown in FIG. 9E , the cut ends of the first and second dielectric sheets 50, 51 are crimped and bonded to each other, so that the two dielectric sheets 50, 51 are integrated, and the integrated two dielectric sheets are utilized. 50, 51, covering each transmission core cable 20. Thus, the signal transmission cable 160 covered with the first and second dielectric sheets 50 and 51 is completed.

Also, as a dielectric sheet. It is preferable to use polyvinyl chloride, polyethylene, etc., which are excellent in bondability after crimping.

The method of manufacturing a signal transmission cable according to the fourth embodiment can simultaneously form a large number of signal transmission cables through a series of simple steps, and thus can manufacture signal transmission cables of a constant quality with small dispersion in characteristics. In addition, since the number of steps is small, the signal transmission cable can be manufactured inexpensively.

10A and 10B are process cross-sectional views showing a method of manufacturing signal transmission cable 170 . FIG. 10A shows the state until the transmission core cable 20 is covered with the first and second dielectric sheets 50, 51 in the cross-sectional view of the process shown in FIGS. 9A-9E (FIG. 9D). Here, the feature is that the first dielectric sheet 50 and the second dielectric sheet 51 are not divided.

Next, as shown in FIG. 10A, along the cable length direction of the transmission core cable 20, and at the position where the transmission core cable 20 is not arranged (between adjacent transmission core cables 20), along the direction of the arrow (the thickness of the cable direction), the first and second dielectric sheets 50, 51 are crimped, and a part of the first and second dielectric sheets 50, 51 are bonded without separating them.

10B shows the state after crimping. The signal transmission cable 170 is enclosed in the dielectric sheets 50 and 51 that are integrated with each other. Furthermore, the signal transmission cable 170 is under the action of the junction of the dielectric sheets 50 and 51. The dielectric sheets 50 and 51 are accommodated in a state of being separated from each other along the cable longitudinal direction, and are connected in a so-called curtain-like state.

In this way, each transmission core cable 20 is firmly fixed by the dielectric sheet, and each transmission core cable 20 is connected in a curtain shape, so it can be used as a flexible multi-core signal transmission cable. In addition, in FIG. 9 and FIG. 10, if a ground layer is provided on the outside of the first and second dielectric sheets 50, 51, a high shielding effect can be obtained.

(fifth embodiment)

A preferred structure of the signal transmission cable 20 of the present invention is to have, in its cable end, a connector structure suitable for coupling with a connection partner. Next, referring to Fig. 11 and Fig. 12, the signal transmission cable of the present invention having a connector structure at the end of the cable will be described. In addition, FIGS. 11 and 12 are cross-sectional views of the transmission core cable 20 cut along the cable length direction, which are different from FIGS. 1 to 10 in which the transmission core cable 20 is cut along the cable width direction.

As shown in FIG. 11, the thickness of the dielectric core layers 10a, 10b at both ends in the cable length direction of the transmission core cable 20 is thicker than the thickness of the dielectric core layer 10 in other regions. Hereinafter, the thick cable ends are referred to as "connector structures 10a, 10b". In this structure, for example, as a pretreatment for forming the first and second conductive layers 11, 12, on both sides of the dielectric core layer 10, along the cable width direction, selectively on both sides of the cable length direction of the transmission core cable 20. It can be easily formed by adding and laminating a dielectric layer at the end. In addition, in FIG. 11 , illustration of the insulator 13 of the transmission core cable 20 is omitted.

FIG. 12 shows the structure of the connector 60 of the connection partner of the transmission core cable 20 formed in this way. At the cable end of the transmission core cable 20, the connector structures 10a, 10b are exposed after removing the cover of the insulator 13 or the like. On the other hand, the end portion of the connector 60 is a conductive clip 61 .

Therefore, by sandwiching the connector structures 10a, 10b of the transmission core cable 20 with the clamp 61 of the connector 60, the transmission core cable 20 and the connector 60 can be connected easily and reliably. Here, it is necessary to dye the first and second conductive layers 11 and 12 in different colors, or to make parts of them different in shape from each other.

In the structure of the signal transmission cable of the present invention, it is necessary to adopt a structure that can clearly distinguish the first and second conductive layers 11 and 12 . Otherwise, when the signal transmission cable is connected to other electrical parts, it may be connected to a conductive layer different from the conductive layer that should be connected, resulting in a phenomenon that the signal cannot be transmitted.

In each of the above-mentioned embodiments of the present invention, the first and second conductive layers 11, 12 are dyed in different colors, or part of their shapes are different from each other, so that the first and second conductive layers 11, 12 can be clearly distinguished. 12 structures. Distinction by color can be implemented as follows, for example.

(the structure of the first color division)

On the surfaces of the first and second conductive layers 11 and 12, respectively form concavities and convexities, and then make the concavo-convex shapes (concave-convex patterns) different from each other between the conductive layers, so that the luminance and brightness are different. Color distinction. For example, when the first and second conductive layers 11 and 12 are made of electrolytic copper foil, a light-emitting surface (glossy surface) and a matte surface (rough surface) are formed on the surface of the conductive layer in the manufacturing method of the copper foil. The colors of the shiny surface and the matte surface differ in the degree to which they can be distinguished by the naked eye. Specifically, the illuminated surface becomes a mirror surface, which reflects light, while the matte surface becomes a dark color. Utilizing this characteristic, one of the first and second conductive layers 11, 12 can be used as a light-emitting surface, and the other can be used as a matte surface, and the two surfaces can be distinguished by color.

(the structure of the second color division)

When the first and second conductive layers 11 and 12 are formed of rolled copper foil, the above-mentioned color distinction cannot be performed. Therefore, for example, the surface of a conductive layer may be scratched, or as a roll for drawing a copper foil to be a conductive layer, a roll capable of forming unevenness on the surface may be selected. In this way, it is possible to visually make the surface shape of one formed conductive layer different from that of the other.

(the structure of the third color division)

The surfaces of the first and second conductive layers 11 and 12 are painted with unique colors using pigments or dyes.

(the structure of the fourth color division)

Form the first and second conductive layers 11 and 12 (first and second conductor sheets 11' and 12') on the dielectric core layer 10 (dielectric core sheet 10') by electroplating and vapor deposition of conductive materials At the same time, in the first and second conductive layers 11 and 12 (first and second conductive sheets 11' and 12'), different formation methods are used to make them visually different from each other. .

(the structure of the fifth color division)

By selectively etching the surface of one of the first and second conductive layers 11 and 12, the shape of the surface is visually different from the shape of the other.

In addition, it is possible not only to distinguish by color, but also to make the shapes of the first and second conductive layers 11 and 12 different from each other. For example, as shown in FIG. 13 , the notch α may be selectively formed only at the corner of one end of the first and second conductive layers 11 and 12 . In addition, as shown in FIG. 14 , holes and recesses may be selectively formed only at one end of the first and second conductive layers 11 and 12 . In FIG. 14A, at one end of the first and second conductive layers 11 and 12, a circular hole or even a concave portion β is formed; in FIG. 14B, one of the first and second conductive layers 11 and 12 The end edge forms a wedge-shaped recess γ.

In this way, after the first and second conductive layers 11 and 12 are colored with different colors, or part of their shapes are different from each other, and the structure of the first and second conductive layers 11 and 12 can be clearly distinguished, then It is easy to identify its connection direction.

(sixth embodiment)

15A, 15B, and 16 are cross-sectional views showing steps of a method of manufacturing a multi-core signal transmission cable according to a sixth embodiment of the present invention.

First, as shown in FIG. 15A, after preparing a plurality of laminate sheets A in which the first conductor sheet 210, the first dielectric sheet 211, and the second conductor sheet 212 are sequentially laminated, the second dielectric sheet 213 is packaged. Next, these laminate sheets A are sequentially stacked, and the respective layers are pressure-bonded to form the long sheet 220 shown in FIG. 15B . Make the length dimension L of the formed long size sheet 220 equal to the length dimension of the multi-core differential transmission cable to be made, so that the width dimension W1 is equal to or several times greater than the width dimension of the multi-core differential transmission cable to be made . The shapes of the first and second conductor sheets 210 and 212 and the first and second dielectric sheets 211 and 213 are set in order to form the elongated sheet 220 of such a size.

Next, as shown in FIG. 16 , the elongated sheet 220 on which the laminate sheet A is stacked is divided along its longitudinal direction (direction perpendicular to the plane of the drawing) according to the cable width W2 indicated by the dotted line. Make the formed long dimension piece 220. Fig. 17A and Fig. 17B are figures in which the elongated sheet 220 is cut along its width direction.

Here, the first conductor sheet 210 and the second conductor sheet 212 form a pair of differential transmission lines that sandwich the first dielectric sheet 211. By dividing the long sheet 220 collectively, many multi-core circuits can be cut out. differential transmission cable 221 .

Fig. 17A is a cut-away figure of a multi-core differential transmission cable 221 along its width direction, and Fig. 17B is an enlarged view of the part of the multi-core differential transmission cable 221 that constitutes a differential transmission line. Enlarged cross-sectional view of the site. In Fig. 17A and Fig. 17B, the multi-core differential transmission cable 221 extends in a direction perpendicular to the drawing. The left and right direction of the multi-core differential transmission cable 221 is called "the cable height direction of the multi-core differential transmission cable 221". This becomes the cable width direction W2 of the multi-core differential transmission cable 221 .

The characteristic impedance of a pair of differential transmission lines composed of the first and second conductor sheets 210, 212, and the ratio h/W2 (h: the interval between a pair of differential transmission lines, W2: differential transmission line The width) is proportional to. Here, since h depends on the initial thickness of the first dielectric sheet 211 and W2 depends on the division width of the elongated sheet 220, the dispersion of characteristic impedance in the multi-core differential transmission cable 221 is very small.

In addition, rolled copper foils having the same thickness (for example, 8 μm) are used for the first and second conductor sheets 210 and 212 . In addition, as the first dielectric sheet 211, a prepreg-state wholly aromatic polyamide film having a predetermined thickness (for example, 30 μm) is used. In addition, the second dielectric sheet 213 is preferably thicker than the first dielectric sheet 211 because it is necessary to insulate and separate the differential transmission lines (the first and second conductor sheets 210 and 212 ).

18A and 18B show the structure of the shielded multi-core differential transmission cable 221 . As shown in FIG. 18A , both surfaces 221 a in the cable width direction of the multi-core differential transmission cable 221 are covered with a conductive film 231 . The conductive film 231 is covered with insulating films 230 and 232 on its upper and lower surfaces, and its width dimension is slightly larger than the cable height dimension of the multi-core differential transmission cable 221 . Conductors of such a shape are disposed on both surfaces 221a of the multi-core differential transmission cable 221 in the cable width direction in a state where both ends of the film in the cable height direction are equally inserted from the ends of the multi-core differential transmission cable 221. Film 231.

Then, as shown in FIG. 18B , the ends of the conductive films 231 protruding from both ends in the height direction of the multi-core differential transmission cable 221 are bonded to each other for electrical connection, thereby completely covering the multi-core differential transmission cable with the conductive film 231. Dynamic transmission cable 221. In this way, the multi-core differential transmission cable 221 is shielded.

However, when connecting separate electronic devices or the like with a transmission cable, a transmission cable having a length of 5 to 10 m or more is required. At this time, as shown in FIG. 19 , it is preferable to roll the long sheet 220 in advance after forming the long sheet 220 . In this way, when cutting the elongated sheet 220, the elongated sheet 220 in the form of a roll can be divided by a slicer (not shown) or the like while pulling out the elongated sheet 220 in the form of a roll, and it is possible to easily form a long-distance multi-core sheet in a limited space. differential transmission cable 221 .

In addition, instead of dividing the roll-shaped elongated sheet 220 while pulling it out, as shown in FIG. 20 , the elongated sheet 220 may be divided while maintaining the roll state. In this case, since the roll-shaped long sheet 220 can be stored and transported in a divided state, production management is facilitated.

The laminate sheet A shown in FIG. 16 is a material constituting only a pair of differential transmission lines. However, it is possible to add a ground layer to the structure of the laminate sheet A to add a shielding effect. FIG. 21 shows a structure in which long sheets of laminated sheets with such a ground layer are laminated.

As shown in FIG. 21, the laminate sheet B is laminated with the first conductor sheet 210, the first dielectric sheet 211, and the second conductor sheet 212, and further laminates the third dielectric sheet 214 and the third conductor sheet 215. . The third dielectric sheet 214 and the third conductor sheet 215 are laminated on the surface of the second conductor sheet 212 in this order. In addition, the third dielectric sheet 214 and the third conductor sheet 215 may be laminated on the surface of the first conductor sheet 210 in this order, or may be laminated on both the first and second conductor sheets 210 and 212. up.

Furthermore, a plurality of laminated body sheets B are sequentially laminated with the second dielectric sheet 213 interposed therebetween, thereby constituting the elongated sheet 220'.

After the long piece 220' is cut to a predetermined width, a multi-core differential transmission cable 221' having a pair of differential transmission lines covered with the third conductor sheet 215 above and below can be obtained. In other words, when the third conductor sheet 215 is used as the ground layer, each differential transmission line of the multi-core differential transmission cable 221' has a structure in which at least the upper and lower sides are shielded.

In addition, the multi-core differential transmission cable 221 has a plurality of differential transmission lines, but the characteristic impedance of each differential transmission line may be set independently. FIG. 22 shows the structure of a multi-core differential transmission cable 221" having differential transmission lines having different characteristic impedance values.

Laminate sheet A1 is composed of a first conductor sheet 210, a first dielectric sheet 211 and a second conductor sheet 212; a laminate sheet A2 is composed of a first conductor sheet 210', a first dielectric sheet 211' and a second Conductor sheet 212'. The characteristic impedance of the differential transmission line depends on the ratio of h/W2 (h: the distance between the differential transmission lines, W: the width of the differential transmission line). Since the long-dimension pieces 220” are uniformly cut, W2 is constant Therefore, after changing the value of h, the setting value of the characteristic impedance can be changed. h depends on the thickness of the initial first dielectric sheet 211, 211'. Therefore, the first dielectric sheet of the laminate sheet A1 is individually set The thickness 211 and the thickness of the first dielectric sheet 211' of the laminate sheet A2 can easily individually set the characteristic impedance value of the laminate sheet A1 and the characteristic impedance value of the laminate sheet A2.

In the multi-core differential transmission cable 221 formed by dividing the long piece 220, it is necessary to provide connectors for connecting to electronic devices or other cables at both ends of the cable.

23A, 23B and 24A, 24B show an example of the structure of a multi-core differential transmission cable 221'' having such a connector structure and an example of its manufacturing method.

Fig. 23A is a plan view of the long-sized sheet 220'', and Fig. 23B is a cross-sectional view of the long-sized sheet 220'' (the laminate sheet is not shown). In these figures, the left-right direction in the figure is the length direction of the cable.

The thick portion 240 is provided at predetermined intervals along the longitudinal direction of the elongated piece 220''. The thick portion 240 is provided over the entire width of the elongated sheet. The interval at which the thick portion 240 is formed adopts the required dimension in the longitudinal direction of the multi-core differential transmission cable. In Fig. 23A and Fig. 23B, the longitudinal dimension of the long dimension piece 220 is many times the longitudinal dimension of the multi-core differential transmission cable, and a plurality of wall thickness portions 240 are arranged at intervals in the cable longitudinal direction. However, when the longitudinal dimension of the long dimension piece 220'' is the same as that of the multi-core differential transmission cable, the wall thickness part 240 is provided at both ends of the lengthwise direction of the long dimension piece 220''.

The thick portion 240 is formed, for example, by selectively increasing the thickness of the second dielectric sheet 213' along the sheet longitudinal direction at the portion where the thick portion 240 is formed. In order to selectively increase the thickness of the second dielectric sheet 213' along the length direction of the sheet, another dielectric sheet having the width of the wall thickness portion 240 may be stacked on the second dielectric sheet 213, for example.

Specifically, as shown in FIG. 23A , the width direction dimension W1 having the cumulative value equal to the width dimension of several multi-core differential transmission cables and the multi-core differential transmission cable having the cumulative value equal to the length dimension of several multi-core differential transmission cables are prepared. The first dielectric sheet 211 having a dimension L in the longitudinal direction. On one surface of the first dielectric sheet 211, the first conductor sheet 210 is laminated, on the other surface, the second conductor sheet 212 is laminated, and further, on the second conductor sheet 212, the second conductor sheet 210 is laminated. Dielectric sheet 213 . As the second dielectric sheet 213, as described above, a material having a thicker sheet thickness along the sheet longitudinal direction is used at the portion where the thick portion is formed. After laminating multiple layers of laminate sheets (the first dielectric sheet 211, the first conductor sheet 210, the second conductor sheet 212, and the second dielectric sheet 213) thus formed, the laminate is crimped and integrated to form a long Size sheet 220.

Then, the long dimension sheet 220'' is divided according to the width direction dimension of the multi-core differential transmission cable, and then divided according to the length direction dimension of the multi-core differential transmission cable. At this time, the divided portion of the longitudinal dimension is arranged on the wall portion 240 . In this way, a plurality of multi-core differential transmission cables 221'' are divided by the long-sized pieces 220''. Furthermore, at the end of the divided multi-core differential transmission cable 221'', the divided thick portion 240 is arranged.

FIG. 24A is an enlarged cross-sectional view of the vicinity of the end of the multi-core differential transmission cable 221'' after dividing the long piece 220'' at the thick portion 240. As shown in FIG. 24A, the thickness of the second dielectric sheet 213' at the end of the multi-core differential transmission cable 221'' (thick portion 240) is thicker than that of the second dielectric sheet 213 in other parts. Furthermore, as shown in FIG. 24B, only the end of the second dielectric sheet 213' can be selectively removed from the end of the multi-core differential transmission cable 221'' (the part of the thick portion 240), so that the first and second 2. Conductor sheets 210, 212 are exposed. In this way, a connector structure can be formed at the end of the multi-core differential transmission cable 221''.

In the sixth embodiment described above, for example, a wholly aromatic polyamide film can be used as the first dielectric sheet 211; Materials such as ethylene glycol formate, polydiphenyl sulfide, and liquid crystal polymers.

(seventh embodiment)

25A to 25D are cross-sectional views showing steps in the cable width direction (perpendicular to the longitudinal direction) of the method of manufacturing the flexible differential transmission cable in the seventh embodiment of the present invention.

As shown in FIG. 25A , a first conductive film 311 is formed on a dielectric sheet 310 , and then, as shown in FIG. 25B , a dielectric film 312 is formed on the first conductive film 311 . Furthermore, as shown in FIG. 25C , a second conductive film 313 is formed on the dielectric film 312 . Next, as shown in FIG. 25D , the second conductive film 313 , the dielectric film 312 , and the first conductive film 311 are cut to form strip-shaped grooves 314 . A plurality of grooves 314 are formed in parallel on the dielectric sheet 310 so as to be parallel to each other. In this way, a plurality of differential transmission lines 315 composed of a laminate of the first conductive film 311, the dielectric film 312, and the second conductive film 313 separated from each other by the groove portion 314 are formed in parallel to each other. Here, the signal line composed of the first conductive film 311 and the second conductive film 313 serves as a pair of differential signal lines.

With the structure of the seventh embodiment, it is possible to simultaneously form a laminated structure consisting of the first conductive film 311 , the dielectric film 312 , and the second conductive film 313 separated from each other by the groove portion 314 while being integrated with the dielectric sheet 310 . A plurality of differential transmission lines 315. Therefore, a flexible differential transmission cable with high production efficiency can be realized.

In addition, the line width of a pair of signal lines constituting the differential transmission line 315 (the width of the first and second conductive films 311 and 313 that are cut) and the distance between the signal lines (the first and second conductive films that become the signal lines) The interval between layers, in other words, the thickness of the dielectric film 312) is uniformly formed. Therefore, the dispersion of the characteristic impedance of the differential transmission line can be reduced, and a highly reliable flexible differential transmission cable can be realized.

Furthermore, if the laminated bodies constituting the differential transmission line 315 are formed with the same width and the same interval, a multi-core differential transmission cable with uniform characteristic impedance can be realized. Therefore, it is possible to realize a flexible differential transmission cable suitable for increasing the capacity of data.

Here, as the dielectric sheet 310 and the dielectric film 312, as long as it is a dielectric material that can maintain the flexibility of the differential transmission cable when forming the differential transmission cable, for example, a wholly aromatic polyamide film in a prepreg state, Polyimide film (thickness, eg, 30-60 μm) and the like (the same applies hereinafter). In addition, for the first and second conductive films 311 and 313, rolled copper foil or the like having the same thickness (for example, 4 to 18 μm) can be used. A wholly aromatic polyamide film; as the second dielectric sheet 213, a polyimide film can be used, but materials such as polyethylene terephthalate, polydiphenyl sulfide, and liquid crystal polymer can also be used.

Using a specific example, as the dielectric sheet 310, a 30 μm thick polyimide sheet is prepared, an adhesive is applied on the dielectric sheet 310, and a 5 μm rolled copper foil is laminated on it as the first conductive film 311, Then laminate a prepreg of a wholly aromatic polyamide film as a dielectric film 312 on it, and then laminate a 5 μm rolled copper foil as a second conductive film 313 on it, heat and press to integrate, and use a microtome to form grooves The flexible differential transmission cable 315 can be manufactured after the portion 314 is made into a desired length.

The characteristic impedance of the differential transmission line 315 depends on the ratio of (the distance between the differential transmission lines)/(the width of the differential transmission line), so as long as the thickness of the dielectric sheet 312 is set according to the width of the differential transmission line 315 That's it.

In addition, the cutting of the first conductive film 311, the dielectric film 312, and the second conductive film 313 can be performed using a cutter such as a slicer, for example. In addition, when cutting with a cutter such as a slicer, in order to prevent the first conductive film 311 or the second conductive film 313 from being short-circuited after generating residue, the cutting can be stopped while leaving a part of the first conductive film 311, that is, cutting. Part of the first conductive film 311 is left halfway in the thickness direction of the first conductive film 311, and the remaining portion of the first conductive film 311 is removed by etching.

As a cutting adjustment method using a slicer to stop cutting while leaving a part of the first conductive film 311, for example, a tool is prepared in which an insulating material or a high-resistance material is covered on the side of the blade as a slicer blade. One terminal was pulled out from the end surface of the integrated cable to form the groove portion 314, and it was processed while measuring the resistance value between the terminal and the blade.

When the tip of the blade cuts through the first conductive film 311, the measured resistance is low, and when the tip of the blade is in the first dielectric film 312, the resistance value becomes high. In order to cut off the thin slices, while adjusting the resistance value, the height of the blade of the slicer is also adjusted, so that it can be processed within the required thickness range. By setting the threshold value of the resistance value, it is possible to adjust whether to leave a part of the first conductive film 311 or to cut deeply to the dielectric sheet 310 .

The method of leaving a part of the first conductive film 311 and removing the remainder of the first conductive film 311 by etching has the following advantages compared to forming the cut groove portion 314 without leaving the first conductive film 311 . That is, if the first conductive film 311 is to be cut safely, a part of the dielectric sheet 310 will be cut due to the influence of processing accuracy. Since the dielectric sheet 310 forming the first conductive film 311 is very thin, when a flexible differential transmission cable is used, the cutting portion of the dielectric sheet 310 is weak and tends to be easily broken. Therefore, a method of cutting the first conductive film 311 while leaving a part, and then removing the first conductive film 311 by etching is most preferable in terms of strength. This method is one of the preferable methods when the dielectric sheet 310 is relatively thin.

In the above method, as an etchant, after etching the conductive film, etc., the part that needs to be removed can be dissolved or decomposed. As an etchant for dissolving or decomposing these dielectric films, insulating films, etc., for example, when using the above-mentioned dielectric film, conductive film, etc., ferrous chloride or the like can be used.

In addition, in order to cut reliably with a slicer, as shown in FIG. 26, after cutting the first conductive film 311, the dielectric film 312, and the second conductive film 313, a part of the dielectric sheet 310 can be cut until the part of the dielectric sheet 310 is bitten. A groove portion 314 is formed up to a part in the thickness direction. As the cutting adjustment method using a microtome, the above-mentioned method can be used.

In this way, if the dielectric sheet 310 is made thick enough, the integrity of the dielectric sheet 310 and the plurality of laminates will not be damaged.

27 is a cross-sectional view showing a structure of a flexible differential transmission cable having a more practical structure than the flexible differential transmission cable formed by the method shown in FIGS. 25A to 25D . In addition, FIG. 27 is a cross-sectional view along the cable width direction.

First, the insulator 316 is buried only in the plurality of strip-shaped grooves 314 so that the surface of the flexible differential transmission cable becomes a flat surface without irregularities. In addition, this state is not shown in FIG. 27 . Thus, the handling of the flexible differential transmission cable is easier.

Furthermore, an insulating layer 317 is formed on the plurality of differential transmission lines 315 and the plurality of grooves 314 embedded in the insulator 316 . In this way, the entire surface of the plurality of differential transmission lines 315 can be protected by the insulator 316 and the insulating layer 317 . In addition, the insulating layer 317 may not be provided, and the state in which the insulator 316 is embedded in the groove portion 314 may be maintained.

Here, as the insulator 316 and the insulating layer 317, an insulating material capable of maintaining flexibility in the state of being a differential transmission cable is used. For example, fluorine-based resins such as FEP (tetrafluoroethylene-hexafluoropropylene heteropolymer resin), amorphous polyolefin resin, PEN (polyphthalate), and the like can be used.

In addition, after forming the plurality of differential transmission lines 315 having the groove portion 314, the insulating layer 317 may be formed on the plurality of differential transmission lines 315 including the groove portion 314, thereby simultaneously forming the groove portion in which the insulator 316 is buried. 314 and the insulating layer 317 on the differential transmission line 315.

Furthermore, as shown in FIG. 27, a ground layer 318 is formed on the insulating layer 317, and a ground layer 319 is formed on the back surface of the dielectric sheet 310, so that the differential transmission line 315 can be shielded by the ground layers 318 and 319. The material for forming the ground layers 318 and 319 is not particularly limited, and for example, rolled copper foil, electrolytic copper foil, etc. may be laminated and used, or those metals may be vapor-deposited.

28A to 28D are process cross-sectional views showing a method of manufacturing a flexible differential transmission cable in a modified example of the seventh embodiment. These figures are cross-sectional views along the width of the cable.

The basic steps of this modification are the same as those shown in FIGS. 25A to 25D. However, the process of the modified example differs from the process shown in FIGS. 25A to 25D in that a plurality of differential transmission lines 315 shielded by the ground layer are simultaneously formed integrally with the dielectric sheet 310 .

First, as shown in FIG. 28A, a first ground layer 320 and a first insulating layer 321 are sequentially formed on a dielectric sheet 310, and then as shown in FIG. 28B, a first conductive film 311, a dielectric film 312 and the second conductive film 313. Furthermore, as shown in FIG. 28C , a second insulating layer 322 and a second ground layer 323 are sequentially formed on the second conductive film 313 . The materials for forming the first ground layer 322 and the second ground layer 323 are not particularly limited. For example, rolled copper foil, electrolytic copper foil, aluminum foil, etc. may be laminated and used, or those metals may be vapor-deposited. In addition, the material for forming the first insulating layer 321 and the second insulating layer 322 is not particularly limited, and examples thereof include fluorine-based resins such as FEP (tetrafluoroethylene-hexafluoropropylene heteropolymer resin), amorphous Polyethylene resin, PEN (polyphthalate), etc. In particular, in order to lower the dielectric constant, it is preferable to form the insulating layer into a foamed shape containing a foaming agent.

Then, as shown in FIG. 28D, the second ground layer 323, the second insulating layer 322, the second conductive film 313, the dielectric film 312, and the first conductive film 311 are cut off, and they are arranged in parallel on the dielectric sheet 310. Many strip-shaped grooves 314 are formed. In this way, a plurality of differential transmission lines 315 separated by the groove portion 314 are formed in parallel. Each differential transmission line 315 is composed of a laminated body of a first conductive film 311 , a dielectric film 312 , a second conductive film 313 , a second insulating layer 322 , and a second ground layer 323 .

According to the method of this modified example, a plurality of differential transmission lines 315 separated by grooves 314 are simultaneously formed in a state integrated with the dielectric sheet 310 . Furthermore, the differential transmission line 315 can be configured to be shielded. Furthermore, like the differential transmission line 315 formed by the method shown in FIGS. , the width of 313) and the interval between the signal lines (that is, the distance between the first and second conductive films, in other words, the thickness of the first dielectric film 312) are formed uniformly, so the characteristics of the differential transmission line can be reduced Impedance dispersion enables highly reliable flexible differential transmission cables.

In addition, as described above, in order to prevent the residue of the first conductive film 311, the second conductive film 313, or the second ground layer 323 (causing short circuit) that may be generated when cutting with a cutting tool such as a slicer, it is possible to Cutting is stopped after a part of the first conductive film 311 is left, that is, the first conductive film 311 is removed by etching in a state where a part of the first conductive film 311 remains. the remnants of.

In addition, although not shown in the figure, as described with reference to FIG. 26 , in order to cut the second ground layer 323, the second insulating layer 322, the second conductive film 313, the dielectric film 312 and the first After the conductive film 311, part of the first insulating layer 321 is bitten and cut in the thickness direction to form the groove portion 314.

29 shows that for the flexible differential transmission cable formed by the method shown in FIGS. 28A-28D , by embedding at least the insulator 316 in the groove portion 314, the surface of the flexible differential transmission cable becomes free. Cross-sectional view of the cable in the width direction (direction perpendicular to the length direction) of the structure of the concave-convex flat surface.

In addition, in order to protect the second ground layer 323, an insulating layer 317 may be further formed on the plurality of differential transmission lines 315 and the plurality of grooves 314 embedded in the insulator 316 as shown in FIG. 29 .

(eighth embodiment)

In a high-density circuit board, a connection structure corresponding to an increase in the density of the input and output terminals is required. In this requirement, how to make the input and output terminals formed on the high-density circuit board with other circuits with high reliability Substrate connection has become an important issue.

For example, the following requirements apply to signal transmission cables used to transmit signals in foldable notebook computers and mobile phones, etc., which include two components:

・It is possible to electrically connect the input and output terminals formed on the respective circuit boards of two components such as a notebook computer and a mobile phone with a fine wiring pitch with high connection reliability;

·With bending-resistant material and structure.

As a signal transmission cable meeting the above-mentioned requirements, in the prior art, for example, there is a signal transmission cable described in Japanese Patent Application Laid-Open No. 2002-134845. In this signal transmission cable, a large number of wires are laid out on one or both sides of a flexible substrate formed of a polyimide film, and connection terminals are formed at both ends thereof.

FIG. 30 shows the structure of a flexible signal transmission cable 700 described in the aforementioned Japanese Patent Document. The flexible signal transmission cable 700 connects the two circuit boards provided on the two structures of the foldable mobile phone. In the flexible signal transmission cable 700, an insulating substrate 701 is provided. The insulating substrate 701 has a shape intended to avoid concentration of bending stress when the mobile phone is folded. On the insulating substrate 701, a plurality of wirings 702 are formed parallel to each other at predetermined intervals. At both ends of each wiring 702, terminals 703 are provided.

After increasing the number of wirings 702 to accommodate multi-terminals of the I/O terminals of the circuit board, it is necessary to form the wirings 702 on both sides of the insulating substrate 701 or to reduce the pitch of the wirings 702 .

However, increasing the number of wires 702 increases the area of the flexible signal transmission cable 700 because the number of terminals 703 formed at both ends of the wires 702 increases. Therefore, high-density connection to a plurality of circuit boards cannot be performed in a limited area.

Also, even if the pitch of the wiring 702 is made finer, unless a large island is provided at the terminal portion of the wiring, it will be difficult to align and connect to another circuit board to be connected. Furthermore, large islands are a factor that hinders the high-density wiring.

On the other hand, when transmitting a high-frequency signal, under the effect of the skin effect of the conductor constituting the wiring 702, for example, the depth of the skin of the conductor required to transmit a signal of 500 MHz is 3 μm, and the depth of the skin when transmitting a signal of 1 GHz is 3 μm. The depth is 2 μm. Since the thickness of the conductor of the wiring 702 is about 40 μm, only 2-3 μm of about 40 μm is used for transmission of high-frequency signals. In this way, the transmission utilization rate per unit cross-sectional area of the conductor for transmitting high-frequency signals is extremely poor.

31A and 31B are a perspective view and a cross-sectional view showing the signal transmission cable 600 of the present invention described in the above-mentioned first embodiment and the like. As shown in FIG. 31A , the signal transmission cable 600 is composed of a laminate sheet in which a plurality of conductor sheets 501 and insulator sheets 502 are alternately laminated. Ends 501a-501g of each conductor sheet 501 are formed stepwise with an insulator sheet 502 interposed therebetween as shown in FIG.

The conductor sheet 501 and the insulator sheet 502 are formed, for example, on the surface of the supporting substrate by methods such as vacuum deposition, sputtering, or CVD. The electrode terminals 501a to 501g formed in steps can be formed by repeatedly performing the following two steps in the process of repeatedly vapor-depositing the conductor sheet 501 and the insulator sheet 502 to form multiple layers, and finally removing the resist.

- A step of vapor-depositing the conductor sheet 510 after covering the end of the insulator sheet 502 to which the conductor sheet 510 does not need to be attached with a resist;

- A step of vapor-depositing the insulator sheet 502 after covering the end of the conductor sheet to which the insulator sheet 502 does not need to be attached with a resist.

The conductor sheet 501 and the insulator sheet 502 formed by this method can be as thin as about 0.5 to 2 μm. Therefore, for example, even if the conductor sheet 510 is stacked in 50 layers, the thickness is 200 μm or less. In this way, the signal transmission cable can exhibit sufficient flexibility.

Alternatively, a rolled copper foil (eg, 5 μm) is used as the conductor sheet 510 , and a wholly aromatic polyamide film in a prepreg state with a predetermined thickness (eg, 30 μm) is used as the insulator sheet 502 . It can also be formed after pressure-bonding by heating and pressing. This method has the advantage that it can be produced at low cost, although the thickness is increased compared with methods such as vapor deposition. In addition, since the conductor sheet 501 and the insulator sheet 502 can be thickly formed, it is also easy to obtain a desired circuit constant.

In this way, the signal transmission cable 600 can provide a signal transmission cable with high wiring density and excellent flexibility. However, since the electrode terminals 501a-501g for taking out the signal lines are formed in steps, when connecting terminals with other circuit boards, etc., it is necessary to prepare special connectors that match the steps. A subject of practical application of the cable 600.

This problem of the signal transmission cable 600 can be solved by adopting the structure of the electrode terminal shown in FIGS. 32A and 32B . In FIG. 32A, a protective layer 503 covering the stepped electrode terminals 501a-501g located at the end of the signal transmission cable 600 is formed, and on the protective layer 503, a via-hole conductor 504a connected to each electrode terminal 501a-501g is formed. After -504g, a plurality of islands 505 are formed on the respective via-hole conductors 504a-504g. In this way, the electrode terminals 501 a - 501 g can be extended to the same surface as the surface of the signal transmission cable 600 .

In FIG. 32B, projections 506a-506g are formed on the stepped electrode terminals 501a-501g. In this way, the electrode terminals 501a to 501g can be extended to the same surface as the surface of the signal transmission cable 600 .

After adopting the structure shown in Fig. 32A and Fig. 32B, the electrode terminals 501a-501g of the conductor sheet 501 formed stepwise, and the via hole conductors 504a-504g extending to the same surface as the surface of the signal transmission cable and The bumps 506a-506g are connected so that they can be easily connected to other circuit substrates.

However, this structure requires extra steps to form the via-hole conductors 504a-504g and the bumps 506a-506g, which increases the cost of the signal transmission cable. In addition, after the step-shaped electrode terminals 501a-501g are connected to the via-hole conductors 504a-504g and the bumps 506a-506g, the reliability may be lowered.

In view of such a problem, the eighth embodiment proposes to arrange electrode terminals on the same plane as the surface of the signal transmission cable by a simple method.

Next, an eighth embodiment will be described with reference to the drawings. In the following drawings, components having substantially the same functions are denoted by the same symbols for brevity of description. In addition, this invention is not limited to the following embodiment.

33A to 33C are process cross-sectional views showing a method of manufacturing the signal transmission cable 610 according to the eighth embodiment of the present invention.

First, as shown in FIG. 33A , the conductor sheets 510 and the insulator sheets 520 are alternately laminated so that the ends of the conductor sheets 510 and the insulator sheets 520 form stepped surfaces, thereby producing a laminated body sheet 610 .

The stepped surface is formed by the following method. That is, in one sheet surface 610b of the sheet end 610a of the laminated body sheet 610, the end of the conductor sheet 510 and the end of the insulator sheet 520 are closer to the other sheet surface 610c. One side of the sheet end 610a is arranged in a stepwise manner, and a stepped surface is formed on one sheet surface 610b of the sheet end 610a.

Here, the end portions 510 a - 510 d of the conductor sheets sequentially exposed on the stepped surface of the laminate sheet 610 constitute electrode terminals of the signal transmission cable 620 .

Next, as shown in FIG. 33B , the resin member 530 is brought into contact with the other sheet surface 610c (the sheet surface on the lowermost sheet 520a side in the figure) of the end portion 610a of the laminate sheet 610 . The shape of the resin member 530 is not particularly limited, but it is preferably a shape corresponding to the shape of the end of the laminated body 610 where the stepped surface disappears (the cross-sectional triangle shape in FIG. 33A ).

In a state where the resin member 530 is pressed against the laminate sheet 610, the resin member 530 and the laminate sheet 610 are pressed in the direction of the arrow in FIG. 33B (sheet thickness direction). Then, as shown in FIG. 33C, the end portion 610a of the laminate sheet 610 is deformed, thereby press-bonding the laminate sheet 610 and the resin member 530, and the stepped surface of the laminate sheet 610 and the uppermost sheet of the laminate sheet The surface of 520e becomes the same plane. Thus, the electrode terminals 510 a to 510 d formed in steps are arranged along the surface of the uppermost sheet 520 e , that is, the surface of the signal transmission cable 620 in the view of the laminate sheet 610 .

Here, the shape of the resin member 530 is made into a shape corresponding to the shape of the end portion of the laminate sheet 610 where the stepped surface is formed and disappears. In other words, if the resin member 530 positioned in contact with the laminate sheet 610 If the other surface 530b on the opposite side of the one surface 530a of the resin member 530 is set approximately parallel to the stepped surface of the laminate sheet 610, the shape of the resin member 530 is set, and when the end of the laminate sheet 610 is deformed, the As shown in FIG. 33C , the other surface 530 b of the resin member 530 is substantially the same surface as the other sheet surface 610 c of the laminate sheet 610 , and the back surface of the signal transmission cable 620 is flattened.

In addition, if the resin member 530 is made of a semi-hardened B-grade resin composed of a thermosetting epoxy resin or polyolefin resin, after the resin member 530 is mounted on the laminate sheet 610, by using When the resin member 530 is cured, the resin member 530 and the laminate sheet 610 can be easily integrated.

Furthermore, when deforming the end portion of the laminate sheet 610, it is preferable to arrange a flat plate 640 on one sheet surface 610b of the laminate sheet 610 as shown in FIG. 33B. In this way, when the resin member 530 is pressed, the step surface of the laminate sheet 610 and the stepped surface of the laminate sheet 610 can be easily connected by contacting the flat plate 540 with the 610b (stepped surface) of one sheet surface of the laminate sheet 610. The other sheet side 610b operates consistently in the same plane.

In the signal transmission cable 620 formed by the manufacturing method described above, the electrode terminals 510a-510d, and the end portion of the one surface 610b of the cable are arranged on the same plane. Therefore, it can be easily connected to terminals of other circuit boards, and in the connection with other electrical structures such as circuit boards, the connector of the prior art can be used as it is, so the manufacturing cost of the connection structure can be reduced. .

In addition, without providing the via-hole conductors 504a-504g and the protrusions 506a-506g shown in FIG. 32A and FIG. 32B, it can be flattened only by a simple process of pressing the resin member 530, and no redundant connection points are generated. The production efficiency is high and high quality can be obtained.

Here, the conductor sheet 510 and the insulator sheet 520 are formed on the surface of the supporting base material, for example, by methods such as vacuum deposition, sputtering, or CAD. The step-shaped electrode terminals 510a-510d are formed by the same method as described above with reference to FIG. 31A and FIG. 31B.

The conductor sheet 510 and the insulator sheet 520 formed by vapor deposition can be as thin as about 0.5 to 2 μm. Therefore, for example, even if the conductor sheet 510 is stacked in 50 layers, the thickness is 200 μm or less. In this way, the signal transmission cable 620 can exhibit sufficient flexibility.

When a signal transmission cable is formed by combining the conductor sheet 510 made of rolled copper foil and the insulator sheet 520 made of a wholly aromatic polyamide film in the form of a prepreg, the thickness is increased compared to the vapor deposition method, but it has The advantage of being able to manufacture cheaply. In addition, since the conductor sheet 510 and the insulator sheet 520 can be thickly formed, it is also easy to obtain a desired circuit constant.

FIG. 34 is a plan view showing the signal transmission cable 620 having the cross-sectional structure shown in FIG. 33C. At the end of the laminate sheet 620 , the electrode terminals 510 a to 510 d are exposed in a strip shape in the width direction of the signal transmission cable 620 . Between the respective electrode terminals 510a-510d, insulator pieces 520a-520d similarly shaped like strips and exposed are provided. Therefore, the electrode terminals 510a-510d are electrically separated by the insulator pieces 520a-520d. In addition, since the width of the conductor sheet 510 can be considerably increased, there is no increase in the resistance of the signal line due to thinning the conductor sheet 510 .

FIG. 35 shows a plan view of a signal transmission cable 620 in which two signal lines are formed in each conductor sheet 510 . As shown in FIG. 35 , the signal lines of width W are formed in parallel, and electrode terminals 510a ₁ -510d ₁ and electrode terminals 510a ₂ -510d ₂ of the signal lines are independently exposed at the end of the laminate sheet. In this way, by forming a plurality of signal lines on each conductor sheet 510 , a high-density signal transmission cable 620 can be obtained.

36A and 36B are cross-sectional views showing steps of a method of manufacturing a signal transmission cable 630 in which the resin member 530 shown in FIGS. 33B and 33C is also used as a reinforcing material for the laminate sheet 610 .

First, as shown in FIG. 36A, in a state where the resin member 531 is in contact with the other sheet surface 610c of the laminate sheet 610, the resin member 531 is pressed in the direction of the arrow in FIG. 36A (sheet thickness direction). and a laminate sheet 610 . The resin member 531 has a flat main body 531a that catches the laminate sheet 610, and an inclined portion 531b that catches an end of the laminate sheet 610 at an end of the main body 531a. The inclined portion 531b has a shape corresponding to the shape of the end portion of the laminated body 630 where the stepped surface disappears.

After the resin member 531 is pressed against the laminate sheet 610, as shown in FIG. The surface and the other sheet surface of the laminate sheet 610 become the same plane. In this way, the electrode terminals 510a to 510d formed in steps are arranged along the surface of the uppermost sheet 520e, that is, the surface of the signal transmission cable in the view of the laminate sheet 630.

In addition, after the resin member 531 is attached to the entire surface of the laminate sheet 610 , the resin member 531 can be used as a reinforcing material of the laminate sheet 610 .

37A and 37B are cross-sectional views showing the arrangement of the electrode terminals when the electrode terminals of the conductor sheet 610 are provided at both ends of the laminate sheet 610 . 37A and 37B are cross-sectional views along the longitudinal direction of the conductor sheet. In FIGS. 37A and 37B , 550 a and 550 b denote regions in which electrode terminals are exposed in the laminate sheet 610 . Regions 550a and 550b are respectively provided at both ends of the sheet surface.

In the structure of FIG. 37A , the regions 550 a and 550 b are arranged on the same sheet surface (one sheet surface 610 b ) of the laminate sheet 610 . The resin member 530 is formed on the sheet surface (another sheet surface 610c) located on the opposite side of the regions 550a, 550b.

In the structure shown in FIG. 37B , the regions 550 a and 550 b are arranged on different sheet surfaces 610 b and 610 c of the laminate sheet 610 , respectively. The resin members 530, 530 are arranged and formed on the sheet surfaces 610c, 610b located on the opposite side to the regions 550a, 550b.

In this way, by appropriately arranging the regions 550a and 550b where the electrode terminals are exposed, connection to other circuit boards and the like can be made more easily.

FIG. 38 shows a configuration in which a signal transmission cable 620 formed according to the eighth embodiment is used for connection between circuit boards 560a and 560b. Since the signal transmission cable 620 has high flexibility, even if it is used in an electronic device such as a foldable notebook computer or a mobile phone, a highly reliable electrical connection can be realized.

FIG. 39 shows a plan view of the signal transmission cable 650 thus formed. In the regions 550a, 550b at both ends of the cable, the electrode terminals 550a, 550b of the signal lines are exposed. As shown in FIG. 39 , many signal transmission cables can be formed at the same time after being cut to a certain width along the longitudinal direction of the laminate sheet (the direction of the dotted line P-Q). In this way, an inexpensive signal transmission cable can be easily obtained.

The eighth embodiment has been described above. But these descriptions are not limiting matters. It goes without saying that various changes can be made. For example: An example in which the conductor sheet 510 is used as a signal line is described. However, in order to reduce the generation of noise, a part of the conductor sheet 510 may also be used as a shielding layer.

In addition, the eighth embodiment is a technique suitable for connecting a plurality of circuit boards at high density. However, this technique can also be applied to wiring substrates.

That is, the resin member can be brought into contact with the end of the sheet on the side that does not become the stepped surface of the laminate sheet, and after pressing the resin member, the stepped surface of the laminate sheet and the uppermost layer of the laminate sheet can be in the same plane. The end portion of the laminated body sheet was deformed to manufacture a wiring board.

Here, the end portion of the conductor sheet exposing the stepped surface of the laminated body sheet constitutes the electrode terminal of the wiring board, and the end portion of the laminated body sheet is deformed so that the electrode terminal is arranged on the same surface as the laminated body sheet. In-plane, exactly the same as the signal transmission cable.

As above, the present invention has been described in detail centering on the most ideal specific examples. However, with regard to the combination and arrangement of components of this ideal embodiment, various changes can be made without departing from the spirit and scope of the present invention described in the following "claims".

Claims (25)

1, a kind of signal-transmitting cable has:

The dielectric sandwich layer that extends along the length direction of cable,

The 1st stacked conductive layer on a face of described dielectric sandwich layer,

Stacked the 2nd conductive layer on another face of described dielectric sandwich layer,

Cover the insulator of described dielectric sandwich layer and described the 1st, the 2nd conductive layer,

Cover the conductive shield of described insulator, and

And then cover the insulating properties crust of described conductive shield;

Described dielectric sandwich layer and described the 1st, the 2nd conductive layer have identical width mutually; Described the 1st, the 2nd conductive layer has identical thickness mutually.

2, signal-transmitting cable as claimed in claim 1 is characterized in that: described the 1st, the 2nd conductive layer constitutes the pair of differential holding wire.

3, signal-transmitting cable as claimed in claim 1 is characterized in that: on described the 1st conductive layer in stacked the 1st dielectric layer, and the stacked the 1st earthy conductive layer on the 1st dielectric layer also;

On described the 2nd conductive layer during stacked the 2nd dielectric layer in, the stacked the 2nd earthy conductive layer on the 2nd dielectric layer also;

Described the 1st dielectric layer, the described the 1st earthy conductive layer, described the 2nd dielectric layer and the described the 2nd earthy conductive layer have identical width with described dielectric sandwich layer, described the 1st conductive layer and described the 2nd conductive layer;

Described the 1st dielectric layer and described the 2nd dielectric layer have identical thickness mutually.

4, signal-transmitting cable as claimed in claim 3 is characterized in that: the thickness of described dielectric sandwich layer is thinner than the described the 1st and the 2nd dielectric layer thickness.

5, signal-transmitting cable as claimed in claim 1 is characterized in that: have a plurality of described transmission core cables, these a plurality of transmission core cables are contained by described insulator.

6, signal-transmitting cable as claimed in claim 1 is characterized in that: described dielectric sandwich layer is made of some in polyimides, fully aromatic polyamide, PETG, poly-hexichol sulfide and the liquid crystal polymer.

7, signal-transmitting cable as claimed in claim 3 is characterized in that: described the 1st conductive layer and described the 2nd conductive layer, the color or the shape on surface are different.

8, a kind of manufacture method of signal-transmitting cable comprises:

Prepare the operation of dielectric core thin slice, wherein, described dielectric core thin slice has sheet length that is equal to or greater than cable length and the sheet width that is equal to or greater than the several times of cable widths;

On the two sides of described dielectric core thin slice, distinguish stacked electric conductor sheet, cover the operation on described two sides;

Cut apart described dielectric core thin slice with cable widths, form the operation of a plurality of transmission core cables simultaneously; And

Each the operation that contains described a plurality of transmission core cables with insulator.

9, the manufacture method of signal-transmitting cable as claimed in claim 8, it is characterized in that: also comprise: after cutting apart described dielectric core thin slice and forming a plurality of transmission core cables, the operation of removing the residue of described dielectric core thin slice residual on the divisional plane of described transmission core cable.

10, a kind of manufacture method of signal-transmitting cable comprises:

Prepare the operation of dielectric core thin slice, wherein, described dielectric core thin slice has sheet length that is equal to or greater than cable length and the sheet width that is equal to or greater than the several times of cable widths;

On the two sides of described dielectric core thin slice, distinguish stacked electric conductor sheet, cover the operation on described two sides;

On described electric conductor sheet, distinguish the layered dielectric sheet, cover the operation of this electric conductor sheet;

On described dielectric piece, distinguish stacked earthy electric conductor sheet, cover the operation of this dielectric piece;

Cut apart described dielectric core thin slice with cable widths, form the operation of a plurality of transmission core cables simultaneously; And

Each the operation that contains described a plurality of transmission core cables with insulator.

11, a kind of manufacture method of multicore differential transmission cable comprises:

Form the operation of duplexer sheet, it stacks gradually the 1st electric conductor sheet, the 1st dielectric piece and the 2nd electric conductor sheet, wherein, described the 1st electric conductor sheet, the 1st dielectric piece and the 2nd electric conductor sheet have the length dimension of the size that is equal to or greater than the cable length direction and the width dimensions of the several times of the size that is equal to or greater than the cable widths direction respectively;

Across the 2nd dielectric piece, stack gradually a plurality of described duplexer sheets, form the operation of long size sheet;

This length size sheet is rolled into the operation of cylinder shape; And

Pull out the end of thin slice from the described long size sheet that is rolled into the cylinder shape on one side, Yi Bian the operation of cutting apart.

12, the manufacture method of multicore differential transmission cable as claimed in claim 11 is characterized in that: as the preceding operation of cutting apart described long size sheet, comprise the operation that this length size sheet is rolled into the cylinder shape;

The operation of cutting apart described long size sheet, from the described long size sheet that be rolled into cylinder shape pull out the end of thin slice on one side, cut apart on one side.

13, a kind of multicore differential transmission cable, has the duplexer sheet that stacks gradually the 1st electric conductor sheet, the 1st dielectric piece and the 2nd electric conductor sheet and form, wherein, described the 1st electric conductor sheet, described the 1st dielectric piece and described the 2nd electric conductor sheet, the length dimension and the width dimensions that equals cable widths direction size that have the size that equals the cable length direction respectively

Described the 1st electric conductor sheet and the 2nd electric conductor sheet, thickness is identical each other;

Described duplexer sheet is the surface of at least one side in described the 1st, the 2nd electric conductor sheet, stacks gradually the 3rd dielectric piece and the 3rd electric conductor sheet;

Across the 2nd dielectric piece, stack gradually a plurality of described duplexer sheets;

Described the 1st electric conductor sheet and the 2nd electric conductor sheet constitute the pair of differential transmission line that clips described the 1st dielectric piece and dispose;

Described the 3rd electric conductor sheet constitutes earth connection.

14, multicore differential transmission cable as claimed in claim 13 is characterized in that: have connector at cable end;

Described connector has the thickness heavy section thicker than other thin slice position of described the 2nd dielectric piece.

15, multicore differential transmission cable as claimed in claim 14 is characterized in that: after removing the part of described the 2nd dielectric piece in the described heavy section, expose described the 1st, the 2nd electric conductor sheet.

16, a kind of manufacture method of flexible differential transmission cable comprises:

On flexible dielectric piece, form the operation of the 1st conducting film;

On described the 1st conducting film, form the operation of dielectric film;

On described dielectric film, form the operation of the 2nd conducting film;

After cutting off described the 2nd conducting film, described dielectric film and described the 1st conducting film, on described dielectric piece, form in the slot part of a plurality of band shapes side by side, between the described slot part of adjacency, form by by this slot part from the operation of the differential transmission circuit that duplexer constituted of described the 1st conducting film, described dielectric film and described the 2nd conducting film; And

After forming described differential transmission circuit, insulant is imbedded the operation of described slot part;

Form the described slot part of mutually the same width, constitute the differential transmission circuit by described duplexer with mutually the same width.

17, the manufacture method of flexible differential transmission cable as claimed in claim 16 is characterized in that: also comprise: the operation that covers described slot part and the described differential transmission circuit of imbedding described insulant with insulating barrier.

18, the manufacture method of flexible differential transmission cable as claimed in claim 17 is characterized in that: also comprise: the operation that forms ground plane on described insulating barrier.

19, the manufacture method of flexible differential transmission cable as claimed in claim 16 is characterized in that: also comprise: the operation that forms ground plane at the back side of described dielectric piece.

20, the manufacture method of flexible differential transmission cable as claimed in claim 16, it is characterized in that: cutting, up to the thickness direction of described the 2nd conducting film, described dielectric film and described the 1st conducting film midway and make described the 1st conducting film stay a part and after forming banded slot part, pass through etch processes, thereby remove the remnants of defeated troops of described the 1st conducting film, implement to form the operation of described slot part.

21, a kind of manufacture method of signal-transmitting cable, comprise: make the duplexer sheet after alternately laminated configuration electric conductor sheet and the sheet insulators, implement stepped configuration simultaneously, the end of the described electric conductor sheet in a side's who makes in the thin slice end of described duplexer sheet the sheet plane and the end of described sheet insulators, the closer to the opposing party's sheet plane one side just the closer to described thin slice end one side, thereby on the described side's of this thin slice end sheet plane, form the 1st operation of cascaded surface;

The 2nd operation that the opposing party's the sheet plane of the described thin slice end of resin component and described laminated body sheet is joined; And

By pushing described resin component along the sheet thickness direction, make the distortion of described thin slice end, thereby make a described cascaded surface and a described side's sheet plane become same, become the 3rd operation that same the described electric conductor sheet that described cascaded surface exposed constitutes electrode terminal respectively thereby make by sheet plane with a described side.

22, the manufacture method of signal-transmitting cable as claimed in claim 21, it is characterized in that: use described resin component: when the sheet plane that makes this resin component and described the opposing party joins with following shape, make the described resin component that joins with described the opposing party's sheet plane one side an another side opposite side, this resin component, with described cascaded surface almost parallel;

In described the 3rd operation, make described thin slice end distortion, thereby make the another side of described resin component, become same with described the opposing party's of described duplexer sheet sheet plane.

23, the manufacture method of signal-transmitting cable as claimed in claim 21, it is characterized in that: described resin component is made of semi-harden shape resin, after described the 3rd operation, also comprise: after making this resin component sclerosis, this resin component and the incorporate operation of described duplexer sheet.

24, the manufacture method of signal-transmitting cable as claimed in claim 21 is characterized in that: use the described resin component with the size of joining with the whole face of described duplexer sheet.

25, the manufacture method of signal-transmitting cable as claimed in claim 21, it is characterized in that: in described the 3rd operation, under the state that the sheet plane that makes flat board with a described side of the described thin slice end of described duplexer sheet joins, push described resin component along the sheet thickness direction.

Images