JP2000269612A - Double-sided flexible printed wiring board - Google Patents

Abstract

(57) Abstract: The present invention prevents serial communication lines wired on a double-sided flexible printed wiring board from being affected by noise and mutual interference between communication lines, and has an advantage of achieving the object.
It is an object of the present invention to provide a double-sided flexible printed wiring board having a multilayer structure capable of being bent at 0 degrees. SOLUTION: A solid pattern GND layer 14 is formed on an upper surface of an upper double-sided flexible printed wiring board 10,
A high-speed serial communication line group 16 is wired on the lower surface, and guard GND layers 18 are formed at both ends. A solid pattern GND layer 20 is also formed on the upper surface of the lower double-sided flexible printed wiring board 12. That is, the high-speed serial signal line group 16 is connected to the solid pattern GND layer 1.
4. The top, bottom, left and right are sandwiched by the solid pattern GND layer 20 and guard GND layer 18 so that
It is in a state where it is guarded in the box of the D layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided flexible printed wiring board, and more particularly to a multilayer double-sided flexible printed wiring board having at least two double-sided flexible printed wiring boards laminated.

[0002]

2. Description of the Related Art In a conventional flexible printed wiring board for connecting between two wiring boards, if the width cannot be made sufficiently large, a double-sided flexible board for wiring circuit signal lines of a predetermined pattern on both upper and lower surfaces. Printed wiring boards were employed.

For this reason, for example, as shown in FIG.
A predetermined pattern of serial communication lines 32 and other circuit signal lines 34 are wired on the upper surface of the double-sided flexible printed wiring board 30, and a predetermined pattern of serial communication lines 36 and other circuits are also formed on the lower surface. In some cases, another circuit signal line 38 was wired.

[0004]

However, in the above-mentioned conventional double-sided flexible printed wiring board 30, the circuit signal lines wired on both sides thereof are similar to the serial communication line groups 32 and 36 for transmitting a large amount of data at high speed. In such a case, external communication noise (hereinafter referred to as “external noise”) or noise generated in the device (hereinafter referred to as “in-machine noise”) is easily disturbed, and noise is mixed in the serial communication signal. I will.

As shown in FIG. 4, when the serial communication line groups 32, 36 wired on both sides of the double-sided flexible printed wiring board 30 overlap each other, these serial communication line groups 32, 36 on both surfaces are overlapped. Mutual interference between communication lines occurs due to capacitive coupling between them, and noise interferes with serial communication signals.

[0006] When noise is mixed in the serial communication signal as described above, data transmitted by the serial communication line groups 32 and 36 cannot be read, and as a result, they are connected by the double-sided flexible printed wiring board 30. Accurate communication between the two wiring boards becomes impossible.

For external noise and in-machine noise, copper foil shielding paper is attached to the outside of the serial communication line groups 32 and 36 wired on both sides of the double-sided flexible printed wiring board 30 to ground (ground; ground). "G
ND "), but it is difficult to actually attach a copper foil shield paper and connect it to the ground.

[0008] Even if somehow copper foil shielding paper is pasted and connected to the ground to prevent the influence of external noise and internal noise, the double-sided flexible printed wiring board 3
It is not possible to prevent interference of noise due to mutual interference between the serial communication line groups 32 and 36 that are wired so that the patterns overlap on both sides of the zero.

As described above, when serial communication lines are wired on both sides of a conventional double-sided flexible printed wiring board, it is difficult to perform accurate communication between the wiring boards connected by the double-sided flexible printed wiring board. There was a problem that is.

When two or more conventional double-sided flexible printed wiring boards are laminated to form a double-layered double-sided flexible printed wiring board, connection is made by interposing an adhesive between adjacent double-sided flexible printed wiring boards. That structure is common.

Therefore, when a double-sided flexible printed wiring board having a multilayer structure is bent, it is difficult to bend the double-sided flexible printed wiring board to a certain degree or more because the thickness of the adhesive connecting the adjacent double-sided flexible printed wiring boards is an obstacle. For example, it was almost impossible to bend by 180 degrees. For example, when the double-sided flexible printed wiring board having a multilayer structure was forcibly bent by 180 degrees, the adhesive portion between the double-sided flexible printed wiring boards was peeled off or turned up.

As described above, the conventional double-sided flexible printed wiring board having a multilayer structure has a problem in that it cannot be arranged by being bent at 180 degrees in a device.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and prevents a serial communication line wired on a double-sided flexible printed wiring board from being affected by noise or mutual interference between communication lines. It is another object of the present invention to provide a double-sided flexible printed wiring board having a multilayer structure capable of being bent at 180 degrees.

[0014]

The above object is achieved by the following double-sided flexible printed wiring board according to the present invention. That is, the double-sided flexible printed wiring board according to claim 1 is a double-sided flexible printed wiring board having a multilayer structure in which at least two double-sided flexible printed wiring boards are laminated. The first double-sided flexible printed wiring board is adjacent to the first double-sided flexible printed wiring board, and the first ground layer is solid-wired on the first surface of the first double-sided flexible printed wiring board.
A plurality of serial communication lines are wired on the surface, and the second surface of the second double-sided flexible printed wiring board facing the second surface of the first double-sided flexible printed wiring board is provided with a second serial communication line.
Are grounded in a solid pattern.

As described above, in the double-sided flexible printed wiring board according to the first aspect, the first ground layer is solidly wired on the first surface of the first double-sided flexible printed wiring board, and a plurality of serial layers are provided on the second surface. Communication line is wired,
The second surface of the second double-sided flexible printed wiring board
Of the first double-sided flexible printed wiring board, the plurality of serial communication lines wired on the second surface of the first double-sided flexible printed wiring board are solid-laid on the first surface of the first double-sided flexible printed wiring board. Since the upper and lower layers are sandwiched between the first ground layer that is wired and the second ground layer that is solidly wired on the first surface of the second double-sided flexible printed wiring board, an external shield is particularly preferable. There is no need to cover a plurality of serial communication lines with a material, and it is possible to block external noise and in-machine noise from a vertical direction with a compact size, and the serial communication signal is not affected by such noise. Further, it is possible to cut off mutual interference between serial communication lines, and noise caused by this mutual interference does not interfere with serial communication signals.

According to a second aspect of the present invention, there is provided the double-sided flexible printed wiring board according to the first aspect, wherein a first double-sided flexible printed wiring board is provided on both sides of the plurality of serial communication lines. 1
And a configuration in which the second guard ground layer is wired, so that a plurality of serial communication lines wired on the second surface of the first double-sided flexible printed wiring board are wired on the same second surface. Since the left and right sides are sandwiched by the first and second guard ground layers, there is no need to cover a plurality of serial communication lines with an external shield material, and the size is compact.
It is possible to block not only external noise and cabin noise from the vertical direction, but also external noise and cabin noise from the left and right directions, that is, it is possible to block noise from all directions. The serial communication signal is almost completely unaffected.

According to a third aspect of the present invention, there is provided the double-sided flexible printed wiring board according to the first aspect, wherein a second surface of the second double-sided flexible printed wiring board has a plurality of serial communication lines other than a plurality of serial communication lines. With this configuration, a complex circuit connection between a plurality of serial communication lines shielded from various noises and other circuit signal lines is realized.

Further, the double-sided flexible printed wiring board according to claim 4 is the double-sided flexible printed wiring board according to claim 1, wherein the first double-sided flexible printed wiring board and the second double-sided flexible printed wiring board are: By being separated at a predetermined interval, the bending of a certain degree or more is not hindered by the thickness of the adhesive connecting the adjacent double-sided flexible printed wiring boards. Bending becomes possible.

In the double-sided flexible printed wiring board according to claim 1, the first ground layer and the plurality of serial communication lines of the first double-sided flexible printed wiring board and the second ground layer of the second double-sided flexible printed wiring board are provided. Is preferably covered with a coverlay film as in the conventional case. In this case, when the double-sided flexible printed wiring board having the multilayer structure is bent at, for example, 180 degrees, even if the adjacent first double-sided flexible printed wiring board and the second double-sided flexible printed wiring board may come into contact with each other, Due to the covering with the coverlay film, the first ground layer and the plurality of serial communication lines of the first double-sided flexible printed wiring board are not short-circuited to the second ground layer of the second double-sided flexible printed wiring board.

Further, in the double-sided flexible printed wiring board according to claim 2, it is preferable that the first and second guard ground layers of the first double-sided flexible printed wiring board are covered with a coverlay film. is there. Also in this case, when the double-sided flexible printed wiring board having the multilayer structure is bent at, for example, 180 degrees, even if the adjacent first double-sided flexible printed wiring board and the second double-sided flexible printed wiring board may be in contact with each other. The first and second guard ground layers of the first double-sided flexible printed wiring board and the second of the second double-sided flexible printed wiring board are covered by the coverlay film.
There is no short circuit with the ground layer.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
An embodiment of the present invention will be described. FIG. 1 is a perspective view showing a part of a multilayered double-sided flexible printed wiring board according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the multilayered double-sided flexible printed wiring board shown in FIG. FIG. 3 is a schematic view showing a state in which the multilayer double-sided flexible printed wiring board shown in FIGS. 1 and 2 is arranged in a device. In FIG. 1, for easy understanding, the space between the two double-sided flexible printed wiring boards is illustrated with a large interval.

As shown in FIGS. 1 and 2, two double-sided flexible printed wiring boards 10, which are pulled out from one wiring board (not shown) and connected to the other wiring board (not shown), Numerals 12 are laminated so as to overlap with the same width.

However, these two-layered double-sided flexible printed wiring boards 10 and 12 are separated at a predetermined interval. That is, the two double-sided flexible printed wiring boards 10 and 12 are not connected by an adhesive or the like, and a space between them is a predetermined space.

A solid pattern GND layer 14 is formed on the upper surface of the upper double-sided flexible printed wiring board 10 of the two double-sided flexible printed wiring boards 10 and 12 having a laminated structure. On the lower surface of the double-sided flexible printed wiring board 10, a high-speed serial communication line group 16 having a predetermined pattern is wired. Also,
A guard GND layer 18 having a predetermined pattern is formed at each end of the serial communication line group 16.

Also, of the two-sided double-sided flexible printed wiring boards 10 and 12, the solid pattern G is also provided on the upper surface of the lower-layer double-sided flexible printed wiring board 12.
An ND layer 20 is formed. On the lower surface of the double-sided flexible printed wiring board 12, a circuit signal line group 22 other than the serial communication lines is wired.

Although not shown, the solid GND layer 14, the serial communication line group 16, and the guard GND layer 1 of the upper double-sided flexible printed wiring board 10 are omitted.
8, and the lower double-sided flexible printed wiring board 12
Solid pattern GND layer 20 and other circuit signal line group 2
2 are each covered with an insulating coverlay film.

As described above, in the two-layered double-sided flexible printed wiring boards 10 and 12, the high-speed serial communication line group 16 wired on the lower surface of the double-sided flexible printed wiring board 10 is changed to the double-sided flexible printed wiring board 10. The upper and lower sides are sandwiched by a solid pattern GND layer 14 on the upper surface and the solid pattern GND layer 20 on the upper surface of the double-sided flexible printed wiring board 12, and left and right are sandwiched by guard GND layers 18 at both ends.

That is, the high-speed serial signal line group 16 includes the solid pattern GND layer 14 and the solid pattern GND layer 2.
0 and the guard GND layer 18 sandwich the upper, lower, left and right sides, as if guarded in a box of the GND layer.

In the two-layered double-sided flexible printed wiring boards 10 and 12, a high-speed serial communication line group 16 is wired on the lower surface of the upper-sided double-sided flexible printed wiring board 10, and the lower-layer double-sided flexible printed wiring board 10 is provided. Since other circuit signal line groups 22 other than the serial communication line group 16 are wired together on the lower surface of the wiring board 12,
A complex circuit connection between the high-speed serial communication line group 16 and another circuit signal line group 22 is realized.

Next, a description will be given of a case where the two multilayer double-sided flexible printed wiring boards shown in FIGS. 1 and 2 are actually arranged in the apparatus. As shown in FIG.
The two multi-layered double-sided flexible printed wiring boards 10 and 12 pulled out from one wiring board 24 and connected to the other wiring board 26 are freely routed inside the device in a state where they are exactly overlapped with each other. Being placed.

At this time, the two multi-layered double-sided flexible printed wiring boards 10 and 12 may be bent at 180 degrees as required. 10, 12
Are separated by a predetermined distance, and the space between the two is a predetermined space, so that the required 180 degree is maintained without being hindered by an adhesive or the like interposed between the two as in the related art. Can be easily bent.

When the two multi-layered double-sided flexible printed wiring boards 10 and 12 are bent at 180 degrees, for example, the double-sided flexible printed wiring board 1
Even if 0 and 12 are in contact, the solid pattern GND layer 14, the serial communication line group 16, and the guard GND layer 18 of the double-sided flexible printed wiring board 10, and the solid pattern GND layer of the double-sided flexible printed wiring board 12 20
And all other circuit signal line groups 22 are covered with a coverlay film (not shown), so that the serial communication line group 16 of the upper layer double-sided flexible printed wiring board 10 is formed.
Also, there is no short circuit between the guard GND layer 18 and the GND layer 20 of the solid pattern of the lower double-sided flexible printed wiring board 12.

As described above, according to this embodiment, the high-speed serial communication line group 16 wired on the lower surface of the upper double-sided flexible printed wiring board 10 is solid on the upper surface of the upper double-sided flexible printed wiring board 10. GN of pattern
D layer 14 and lower double-sided flexible printed wiring board 12
The upper and lower layers are sandwiched by the solid pattern GND layer 20 on the upper surface and the guard GND layers 1 at both ends.
By being sandwiched on the left and right by 8,
Since the high-speed serial communication line group 16 is guarded in the GND layer box, there is no need to cover the serial communication line group 16 with an external shielding material, and the size is compact. This makes it possible to block external noise and in-machine noise from all directions (up, down, left, and right), and to completely prevent serial communication signals from being affected by such noise. In addition, it is possible to block mutual interference between serial communication lines, and it is possible to prevent noise caused by the mutual interference from interfering with serial communication signals.

A high-speed serial communication line group 16 shielded from external noise and the like is wired on the lower surface of the upper double-sided flexible printed wiring board 10, and the serial communication line group 16 is provided on the lower surface of the lower double-sided flexible printed wiring board 12. Since the circuit signal line group 22 other than the line is wired, a complex circuit connection between the high-speed serial communication line group 16 and the other circuit signal line group 22 can be realized. This can contribute to the miniaturization of the double-sided flexible printed wiring board and the miniaturization of the equipment.

The two-layered flexible printed wiring boards 10 and 12 having a multilayer structure are separated at a predetermined interval, and a space is provided between the two at a predetermined interval. Since it can be easily bent by 180 degrees as needed without being hindered by an adhesive or the like interposed therebetween, the arrangement in the device when connecting the two wiring boards 24 and 26 can be freely performed. This makes it possible to realize a free set design.

In addition, when these two multi-layered double-sided flexible printed wiring boards 10 and 12 are bent at, for example, 180 degrees, even if the double-sided flexible printed wiring boards 10 and 12 come into contact with each other, even if the double-sided flexible printed wiring boards 10 and 12 come into contact with each other, the upper-layer double-sided flexible printed wiring board 10 Serial communication line group 16 and guard G of plate 10
Since the ND layer 18 and the GND layer 20 of the solid pattern of the lower double-sided flexible printed wiring board 12 are all covered with the coverlay film, no short circuit occurs.

In the above embodiment, two double-sided flexible printed wiring boards 10 and 12 having a multilayer structure have been described, but the number of laminated double-sided flexible printed wiring boards having a multilayer structure is limited to two. Instead, it may have a multilayer structure of three or more sheets.

In this case, in two adjacent double-sided flexible printed wiring boards arbitrarily selected from three or more multilayered double-sided flexible printed wiring boards, one double-sided flexible printed wiring board as in the above embodiment is used. A high-speed serial communication line group wired on the lower surface of the printed wiring board has a solid pattern GND layer on the upper surface of the same double-sided flexible printed wiring board and a solid pattern GND layer on the upper surface of the other double-sided flexible printed wiring board. And the left and right sides are sandwiched by the guard GND layers at both ends, and the same effects as in the above embodiment can be obtained.

[0039]

As described above, according to the double-sided flexible printed wiring board of the present invention, the following effects can be obtained. That is, according to the double-sided flexible printed wiring board of the first aspect, the first ground layer is solidly wired on the first surface of the first double-sided flexible printed wiring board, and a plurality of serial communication lines are provided on the second surface. The second ground layer is solidly wired on the first surface of the second double-sided flexible printed wiring board that is wired and is adjacent to the first double-sided flexible printed wiring board,
The plurality of serial communication lines on the second surface of the first double-sided flexible printed wiring board are connected to the first ground layer on the first surface of the first double-sided flexible printed wiring board and the first ground layer of the second double-sided flexible printed wiring board. Since the structure is sandwiched between the upper and lower sides by the second ground layer on the surface, there is no need to cover a plurality of serial communication lines with an external shield material in particular. It is possible to cut off noise,
It is possible to prevent the serial communication signal from being affected by such noise. In addition, it is possible to block mutual interference between serial communication lines, and it is possible to prevent noise caused by the mutual interference from interfering with serial communication signals.

According to the double-sided flexible printed wiring board of the second aspect, the first and second flexible printed wiring boards are provided on both sides of a plurality of serial communication lines of the first double-sided flexible printed wiring board.
, The plurality of serial communication lines on the second surface of the first double-sided flexible printed wiring board are sandwiched vertically by the first ground layer and the second ground layer. In addition to the above structure, the left and right sides are sandwiched by the first and second guard ground layers, so that there is no need to cover a plurality of serial communication lines with an external shield material, and the size is compact. In addition, external noise and in-machine noise from all directions (up, down, left, and right) can be cut off, and the serial communication signal can be almost completely prevented from being affected by the noise.

Further, according to the double-sided flexible printed wiring board according to the third aspect, the circuit signal lines other than the plurality of serial communication lines are wired on the second surface of the second double-sided flexible printed wiring board. Since it is possible to realize a complex circuit connection between a plurality of serial communication lines shielded from various noises and other circuit signal lines, it is possible to reduce the size of the double-sided flexible printed wiring board having a multilayer structure, This can contribute to downsizing of the device.

According to the double-sided flexible printed wiring board of the fourth aspect, the adjacent first double-sided flexible printed wiring board and second adjacent double-sided flexible printed wiring board are separated at a predetermined interval. As a result, a certain degree of bending is not hindered by the thickness of the adhesive connecting the adjacent double-sided flexible printed wiring boards as in the related art,
Since it can be easily bent at 80 degrees, it is possible to freely arrange the components in the device, and a free set design can be realized.

Further, according to the double-sided flexible printed wiring board of the fifth aspect, the first ground layer and the plurality of serial communication lines of the first double-sided flexible printed wiring board and the second double-sided flexible printed wiring board are formed. When the multi-layered double-sided flexible printed wiring board is bent at, for example, 180 degrees, the first double-sided flexible printed wiring board and the second double-sided flexible printed board are adjacent to each other when the double-layered flexible printed wiring board having a multilayer structure is bent at 180 degrees. Even if the wiring board makes contact, even if the first ground layer and the plurality of serial communication lines of the first double-sided flexible printed wiring board and the second ground layer of the second double-sided flexible printed wiring board are short-circuited. Can be prevented from occurring.

Further, according to the double-sided flexible printed wiring board according to the sixth aspect, the first and second guard ground layers of the first double-sided flexible printed wiring board are covered with the cover lay film, so that the multi-layered printed wiring board can be multilayered. When the double-sided flexible printed wiring board having the structure is bent at, for example, 180 degrees, even if the adjacent first double-sided flexible printed wiring board and the second double-sided flexible printed wiring board come into contact with each other, the first double-sided flexible printed wiring board is contacted. It is possible to prevent a short circuit from occurring between the first and second guard ground layers of the board and the second ground layer of the second double-sided flexible printed wiring board.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a part of a double-sided flexible printed wiring board having a multilayer structure according to an embodiment of the present invention.

FIG. 2 is a sectional view of the double-sided flexible printed wiring board having the multilayer structure shown in FIG.

FIG. 3 is a schematic view showing a state in which the multilayer double-sided flexible printed wiring board shown in FIGS. 1 and 2 is arranged in a device.

FIG. 4 is a perspective view showing a conventional double-sided flexible printed wiring board.

[Explanation of symbols]

10: Upper double-sided flexible printed wiring board, 12
...... Lower double-sided flexible printed wiring board, 14 ...
Solid pattern GND layer, 16 high-speed serial communication line group, 18 guard GND layer, 20 solid pattern GND layer, 22 other circuit signal line group other than serial communication line, 24 .., 26 wiring board, 30 double-sided flexible printed wiring board, 32 high-speed serial communication line group, 34 circuit signal lines other than serial communication lines, 3
6 high-speed serial communication line group, 38 other circuit signal lines other than serial communication line

Claims (6)

[Claims] 1. A double-sided flexible printed wiring board having a multilayer structure in which at least two double-sided flexible printed wiring boards are laminated, wherein a first double-sided flexible printed wiring board and a second double-sided flexible printed wiring board are provided. A first ground layer is solidly wired on a first surface of the first double-sided flexible printed wiring board, and a plurality of serial communication lines are wired on a second surface; A double-sided flexible printed wiring board, wherein a second ground layer is solidly wired on a first surface of the second double-sided flexible printed wiring board facing a second surface of the double-sided flexible printed wiring board. 2. The double-sided flexible printed wiring board according to claim 1, wherein first and second guard ground layers are respectively wired on both sides of the plurality of serial communication lines of the first double-sided flexible printed wiring board. A double-sided flexible printed wiring board. 3. The double-sided flexible printed wiring board according to claim 1, wherein circuit signal lines other than the plurality of serial communication lines are wired on a second surface of the second double-sided flexible printed wiring board. Features a double-sided flexible printed wiring board. 4. The double-sided flexible printed wiring board according to claim 1, wherein the first double-sided flexible printed wiring board and the second double-sided flexible printed wiring board are provided.
Characterized by being separated from the double-sided flexible printed wiring board at a predetermined interval. 5. The double-sided flexible printed wiring board according to claim 1, wherein the first double-sided flexible printed wiring board has a first shape.
Wherein the ground layer, the plurality of serial communication lines, and the second ground layer of the second double-sided flexible printed wiring board are covered with a coverlay film. 6. The double-sided flexible printed wiring board according to claim 2, wherein the first double-sided flexible printed wiring board is a first flexible printed wiring board.
And a second guard ground layer covered by a cover lay film.