JPH0983108A - Method and device for manufacturing circuit board - Google Patents

Abstract

(57) [Summary] [Purpose] A release film is continuously adhered to the front and back of a prepreg sheet in high quality to obtain a high quality circuit board. [Structure] The heating rolls 4a and 4b and the cooling roll 5 with only the release film 2 of the release film supply units 3a and 3b arranged in advance above and below in contact with the release agent application surface.
When the release film cutting portion 8 is attached in a state where the release film 7 passes through a and 5b and protrudes to an appropriate amount, the release film 2 is provided with an arbitrary number of slits 10 and sent to the heating rolls 4a and 4b. . Then, when the prepreg sheet 1 is charged from the charging section 6 to the rotating section of the heating rolls 4a, 4b, it passes through the heating rolls 4a, 4b and the cooling rolls 5a, 5b and is melted by heating and pressurizing.
After the release film 2 divided into an arbitrary number with the resin component is adhered, it is discharged to the take-out section 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for manufacturing a circuit board in which a releasable film is adhered to the front and back of a prepreg sheet and used as a mask when filling a conductive paste.

[0002]

2. Description of the Related Art In recent years, with the miniaturization and high density of electronic devices, there has been a strong demand for multilayered circuit boards not only in industrial fields but also in consumer fields. In such a circuit board, it is essential to develop a connection method for connecting inner layer vias between circuit patterns of multiple layers and a new development of a highly reliable structure. A high-density circuit board manufacturing method is proposed in, for example, Japanese Patent Laid-Open No. 6-268345. A method of manufacturing this circuit board will be described below.

FIGS. 6A to 6F are process sectional views showing a method of manufacturing a double-sided circuit board serving as a base of a multilayer board. Reference numeral 1 indicates a thickness of 200 to 300 processed into a 500 mm square made of a composite material in which, for example, a non-woven aromatic polyamide fiber is impregnated with a thermosetting epoxy resin and has pores inside.
A prepreg sheet having a width of 550 mm and a thickness of 12 μm in which a Si-based release agent is applied to one surface of polyethylene terephthalate (PET) is a roll-shaped release film having a thickness of 12 μm. First, the prepreg sheet 1 (FIG. 6 (a)) to which the release film 2 is adhered is attached to a predetermined portion of FIG.
As shown in (b), the through hole 22 is formed by using a laser processing method or the like. Next, as shown in FIG. 6C, the through holes 22 are filled with the conductive paste 23. As a method of filling the conductive paste 23, the prepreg sheet 1 having the through holes 22 is placed on a table of a printing machine (not shown), and the conductive paste 23 is directly printed on the release film 2. At this time, the releasable film 2 on the upper surface plays the role of a printing mask and the role of preventing contamination of the surface of the prepreg sheet 1. Next, as shown in FIG. 6D, the release film 2 is peeled from both surfaces of the prepreg sheet 1. Next, as shown in FIG. 6E, metal foil 24 such as copper foil is attached to both surfaces of the prepreg sheet 1. By heating and pressurizing with a hot press in this state, FIG.
As shown in (f), the thickness of the prepreg sheet 1 is compressed (t1> t2), and the prepreg sheet 1 and the metal foil 24 are bonded together. At this time, prepreg sheet 1
The resin component is cured by heating. Then, the metal foils 24 on the front and back sides are selectively etched to form a circuit pattern, and a double-sided circuit board is obtained.

As described above, the release film 2 adhered to the front and back of the prepreg sheet 1 in the manufacture of the circuit board has through holes formed by laser processing or the like, and is used as a mask when printing the conductive paste. However, it is peeled off after printing.

The process of bonding the prepreg sheet and the release film in the conventional method for manufacturing a circuit board will be described below. For the adhesion, a general laminator used for laminating a photosensitive dry film is used.

FIG. 7 is a cross-sectional view of the laminator used for bonding the prepreg sheet and the release film.

The laminator is a release film supply unit 51.
a, 51b, a pair of heating rolls 52a, 52b and a pair of cooling rolls 53a, 5 whose pressure is variable and whose temperature can be adjusted.
3b, prepreg sheet supply section 54 and take-out section 55
It is composed of

Reference numeral 1 denotes a thickness of 200, which is made of a composite material obtained by impregnating a non-woven aromatic polyamide fiber with a thermosetting epoxy resin and having pores inside, into a 500 mm square.
˜300 μm prepreg sheet (hereinafter referred to as prepreg sheet), and 2 is a width 550 in which one side of polyethylene terephthalate (PET) is coated with a Si-based release agent.
It is a roll-shaped releasable film having a thickness of mm and a thickness of 12 μm. Roll-shaped release films 2 are attached to the release film supply units 51a and 51b arranged above and below the laminator in such a manner that the prepreg sheet 1 is sandwiched between the release agent application surfaces. The heating rolls 52a and 52b and the cooling rolls 53a and 53b are arranged in this order in the moving direction of the releasable film 2, and the charging portion 54 of the prepreg sheet 1 is provided in front of the heating rolls 52a and 52b. 5
A take-out portion 55 is provided behind 3b. The heating rolls 52a and 52b and the cooling rolls 53a and 53b are φ70.
mm metal roll with a thickness of 5 mm and heat-resistant silicone rubber with a rubber hardness of 70, diameter φ80 mm, length 700
The surface temperature of the heating rolls 52a and 52b is controlled to 120 ° C. The heating rolls 52a and 52b and the cooling rolls 53a and 53b are each pressurized with an air pressure of ² Kg / cm ² . The laminating speed is 1 m / min. In addition, the release film 2
The tension is about 1000 g / m.

The release film 2 and the prepreg sheet 1 are bonded to each other by heating only the release film 2 of the release film supply parts 51a and 51b which are arranged above and below in a state where the release agent coating surface is in contact with the release film 2. The prepreg sheet 1 is inserted into the feeding section 5 with the prepreg sheet 1 passing through the rolls 52a and 52b and the cooling rolls 53a and 53b and protruding from the take-out section 55 by an appropriate amount.
4 into the rotating part of the heating rolls 52a and 52b, and passes through the heating rolls 52a and 52b and the cooling rolls 53a and 53b, and the resin component of the prepreg sheet 1 melted by heating and pressurization forms the releasable film 2 Are bonded and discharged to the take-out section 55. For the second and subsequent sheets, the prepreg sheet 1 is sequentially supplied from the supply unit 54 to the heating rolls 52a and 52b.
It can be bonded continuously by putting it in the rotating part.

[0010]

However, in the above-mentioned conventional structure, since the resin component in the prepreg sheet is softened by heating to lower the rigidity, the following problems are caused by the heat shrinkage force and tension of the release film. appear.

The releasable film is stretched in the mechanical feed direction by the laminator temperature and tension, and is attached in a direction orthogonal to one mechanical feed in a state of being stretched in the mechanical feed direction and contracted by heat shrinkage. The release film is adhered to the prepreg sheet while being stretched in each direction by heating and pressurizing the roll, and is cooled by the cooling roll. At this time, since tension still acts between the heating roll and the cooling roll, a contraction force due to the tension and cooling is generated in the release film, and the contraction force causes the prepreg sheet to deform as shown in FIG. This phenomenon occurs between the prepreg sheets in which the contraction force of the release film becomes large, and also at the end of the prepreg sheet, and becomes larger as the gap between the prepreg sheets becomes wider. That is, when the prepreg sheet is under the pressure of both the heating roll and the cooling roll, the contraction force of the release film is absorbed by the adhered prepreg sheet, but when the prepreg sheet is removed from the heating roll, only the release film is released. And shrinks under the influence of heat shrinkage and tension (stretches in the mechanical feed direction)
It becomes easier to do this, and as a result, the end of the prepreg sheet will be affected. Due to such deformation of the prepreg sheet, there is a problem that the laser focus is deviated due to the formation of the through hole by the laser processing at the time of manufacturing the circuit board, the stable hole processing cannot be performed, and the connection resistance becomes unstable.

Further, the feed rates of the heating roll and the cooling roll are generally synchronized, but even if the pressing force is the same, the amount of stretching of the release film increases depending on the heating conditions, so that heating and A slack as shown in FIG. 9 occurs between the cooling rolls, and when the cooling roll pressurizes, folds and wrinkles occur including the prepreg sheet. Alternatively, here, a roll having a silicon rubber lining is used as the heating roll and the cooling roll, but when a metal roll is used for heating and a silicon rubber is used for cooling, the metal roll is in line contact even if pressure is applied, so that it is separated. Although the tension of the moldable film does not fluctuate significantly, the silicon rubber roll becomes surface contact and the tension increases in proportion to the pressure, and a large tension acts between the heating roll and the cooling roll, resulting in a mechanical release film bonded by the heating roll. There is a problem that a part of the film is peeled off after passing through a cooling roll where the tension is eliminated, and heating and pressurizing conditions are limited to a very narrow range.

The present invention is to solve the above-mentioned conventional problems, and to manufacture a circuit board for realizing a high-performance and high-quality circuit board by continuously adhering a release film to the prepreg sheet with high quality. It is an object to provide a method and a device.

[0014]

In order to achieve the above object, the first method of manufacturing a circuit board according to the present invention comprises a part of a plurality of prepreg sheets when the prepreg sheet and the release film are bonded in advance. And a release film is heated and adhered to the front and back of the prepreg sheet.

In the second method for manufacturing a circuit board of the present invention, when the prepreg sheet and the release film are bonded together, the release film is divided into an arbitrary number and then heated and bonded. It is a thing.

Further, according to the third method of manufacturing a circuit board of the present invention, when the prepreg sheet and the release film are adhered to each other, a part of the release film is divided into an arbitrary number with a predetermined length. After that, the undivided part of the release film is positioned so as to be bonded to the input ends of the front and back of the prepreg sheet, and the prepreg sheet is heated and bonded.

Further, in the circuit board manufacturing apparatus of the present invention, heating means for heating and feeding the prepreg sheet provided with the release film, and cooling the prepreg sheet heated by the heating means to cool the prepreg sheet. It is provided with a cooling means for feeding at a higher speed than the heating means, and a take-out portion for taking out the prepreg sheet cooled by the cooling means.

[0018]

According to the present invention, in the first method, the prepreg sheet can absorb the influence of the shrinkage force of the release film after heating by heating the prepreg sheets in a state where some of them are overlapped with each other. The deformation of the sheet can be suppressed only to the final prepreg sheet.

In the second method, the release film is divided and then heated to bond it to the prepreg sheet.
Since the amount of shrinkage of the release film due to the tension and heat shrinkage can be reduced according to the number of divisions of the release film, the deformation of the prepreg sheet can be suppressed.

In the third method, a part of the releasable film is divided into an arbitrary number with a predetermined length, and the undivided part of the releasable film is inserted into the front and back input ends of the prepreg sheet. By positioning and heating to bond,
Similar to the second method, when the deformation of the prepreg sheet is suppressed and the release film is peeled off, the peeling operation can be performed only once regardless of the number of divisions.

Further, in the circuit board manufacturing apparatus of the present invention, since the prepreg sheet heated by the heating means is cooled and the prepreg sheet is sent at a higher speed than the heating means, the releasable film is provided. Since a constant tension can be applied to the prepreg sheet, it is possible to eliminate the folding wrinkles of the prepreg sheet and the peeling failure of the release film due to the tension.

[0022]

EXAMPLES The steps of bonding the prepreg sheet and the release film in the examples of the present invention will be described below.

(First Embodiment) Since the schematic structure of the laminator is basically the same as that of the conventional example, detailed description thereof will be omitted, and the bonding step will be described with reference to FIGS. 1 and 7.

A roll-shaped release film 2 having a width of 550 mm and a thickness of 12 μm and a non-woven aromatic polyamide fiber impregnated with a thermosetting epoxy resin were processed into a 500 mm square made of a composite material having pores inside. Thickness 200-30
Adhesion with the 0 μm prepreg sheet 1 is performed in the state where the release agent coating surface is in contact with only the release film 2 of the release film supply portions 51a and 51b arranged in advance above and below.
Heat roller 5 with diameter φ80mm and length 700mm lined with heat-resistant silicone rubber controlled at 20 ℃
Diameter φ lined with 2a, 52b and heat resistant silicone rubber
Cooling rolls 53a and 53b having a length of 80 mm and a length of 700 mm
With a proper amount of material passing through the ejector 55,
When the prepreg sheet 1 cut into a predetermined size is loaded into the heating rolls 52a and 52b from the loading section 54 by the second and subsequent prepreg sheets 1, as shown in FIG. Overlapped with each other, put in as an apparently continuous prepreg sheet 1, passed through heating rolls 52a and 52b and cooling rolls 53a and 53b, and bonded by a resin component of the prepreg sheet 1 melted by heating and pressurizing, It is discharged to the take-out section 55. When the prepreg sheet 1 and the release film 2 are bonded, the heating rolls 52a, 52b and the cooling rolls 53a, 53
The pressure of b is 2 kg / cm ² and the feed rate is 1 m / mi.
m, and the tension of the release film 2 is 1000 g /
m.

200 pieces of 500 mm square prepreg sheets 1 were continuously adhered using the adhering method of the present invention, but the deformation of the prepreg sheet 1 due to the tension of the release film 2 occurred at the end of the last prepreg sheet 1. However, the remaining prepreg sheet 1 was continuously deformed without being deformed. That is, by partially overlapping the prepreg sheets with each other to be in a continuous state, the influence of the contracting force of the release film 2 can be absorbed by the prepreg sheet, and the deformation of the prepreg sheet 1 can be suppressed only to the final prepreg sheet.

Next, circuit boards on both sides were manufactured by using the undeformed prepreg sheet 1 in which the releasable film 2 was adhered to the front and back by the above method. Since the method of manufacturing the circuit boards on both sides is the same as that of the conventional example, the description thereof is omitted here.

In the circuit boards on both sides obtained by the manufacturing method of the present invention, since the prepreg sheet 1 is not deformed, the laser focus does not deviate in forming the through holes by the laser processing, so that a stable hole shape is obtained. It was confirmed that the connection resistance was stable.

(Second Embodiment) A description will be given below of the step of adhering the prepreg sheet and the release film in the method for manufacturing a circuit board according to the second embodiment of the present invention.

FIG. 2 is a schematic structure of a laminator used for bonding the prepreg sheet and the release film and a sectional view of the bonding process. Reference numeral 1 denotes a thickness 200 processed into a 500 mm square, which is made of, for example, a composite material obtained by impregnating a non-woven aromatic polyamide fiber with a thermosetting epoxy resin and having pores inside.
˜300 μm aramid-epoxy sheet (hereinafter referred to as prepreg sheet), 2 is a width of 550 m in which one side of polyethylene terephthalate is coated with a Si-based release agent
m is a release film in a roll shape having a thickness of 10 μm.
Since the roll-shaped release film 2 holds the prepreg sheet 1 on the release agent application surface, the release film supply units 3a and 3b are arranged above and below the laminator. Is the release agent coated surface on the upper side, the lower PE
The T supply part 3b is attached so that the release agent application surface is on the lower side. The free roll 11, the release film cutting unit 8, the free roll 11, the heating rolls 4a and 4b, and the cooling rolls 5a and 5b are arranged in this order in the traveling direction of the release film 2, respectively. The charging section 6 of the prepreg sheet 1 is provided with the cooling roll 5 on the charging side of 4a and 4b.
A take-out portion 7 is provided behind a and 5b. In addition,
When static electricity is generated due to the adhesion between the prepreg sheet 1 and the release film 2, a static electricity removing device may be provided behind the cooling rolls 5a and 5b.

The releasable film cutting section 8 is composed of a rod to which five cutter knives 9 are attached at a pitch of about 90 mm and a holding section (not shown), and has a detachable structure. As for the rod, the release film 2 in the upper and lower release film supply portions 3a and 3b is used as a free roll 11 and a heating roll 4.
a and 4b and cooling rolls 5a and 5b are attached to the holding portion in a state where they can be adhered to each other as shown in FIG.
The release film 2 has five slits 10 with a width of about 90 mm.
When the heating rolls 4a and 4b and the cooling rolls 5a and 5b are rotated, they are sent to the heating rolls 4a and 4b.

The heating rolls 4a and 4b are rolls of φ80 mm and 700 mm in length obtained by lining a φ70 mm metal roll with a heat-resistant silicone rubber having a rubber hardness of 70. The surface temperature is controlled to 120 ° C. and 2.0 kg / cm.
Pressurized with air pressure of ² . Feed rate is 1m / min
Is set to

The cooling rolls 5a, 5b are rolls of φ80 mm and length of 700 mm, which are made by lining a heat-resistant silicone rubber having a rubber hardness of 70 on a metal roll of φ70 mm and having a length of 2K.
Pressurized with an air pressure of g / cm ² . Cooling roll 5
a and 5b are heating rolls 4a and 4 whose feeding speeds are set without the release film 2 and the prepreg sheet 1 being set.
A torque control device (not shown) is provided on the cooling roll 4b that controls the rotation by setting about 20% faster than
The structure is such that a constant tension of / m works.

The tension of the release film 2 between the release film supply sections 3a and 3b and the heating rolls 4a and 4b is 1
It is set to 000 g / m.

The release film 2 and the prepreg sheet 1 are adhered to each other as follows.

Only the releasable film 2 of the releasable film supply portions 3a and 3b arranged in advance above and below is taken out by passing the heating rolls 4a and 4b and the cooling rolls 5a and 5b in a state where the release agent coating surface is in contact. When the releasable film cutting portion 8 is attached in a state where the releasable film is protruded to the portion 7, the releasable film 2 is divided into slits 10 at a pitch of about 90 mm and sent to the heating rolls 4a and 4b. Then, the prepreg sheet 1 is fed from the charging section 6 to the heating roll 4
When placed in the rotating parts of a and 4b, the heating rolls 4a and 4b
4, the release film 2 divided by the resin component of the prepreg sheet 1 melted by heating and pressing passes through the cooling rolls 5a and 5b, is adhered as shown in FIG. . The second and subsequent sheets are prepreg sheets 1
By successively introducing the above into the rotating parts of the heating rolls 4a and 4b from the introducing part 6, the continuous adhesion can be achieved. 5 by the bonding method of the present invention
200 pieces of prepreg sheets 1 of 00 mm square were continuously adhered, but the deformation of the prepreg sheets 1 due to the tension of the release film 2 was suppressed to a level where there was no problem in defocusing during laser processing, and stable adhesion without creases. I was able to do it continuously. In this way, the release film 2 is divided and then adhered to the prepreg sheet 1, so that the amount of shrinkage of the release film 2 in the direction orthogonal to the mechanical feeding due to the tension or heat shrinkage of the release film 2 is divided. Since the size can be reduced according to the number, the deformation of the prepreg sheet 1 can be suppressed.

The amount of shrinkage in the mechanical feed direction due to the tension and heat shrinkage of the release film 2 is estimated to be about 3% from the tension and the amount of elongation of the release film 2 during heating. If the width of the release film 2 is 530 mm, shrinkage of about 15 mm occurs. On the other hand, when it is divided into 90 mm widths, it is smaller than 2.7 mm and 530 mm, which is 1/5 or less. It is for this reason that the deformation of the prepreg sheet 1 is drastically reduced, and it goes without saying that the effect becomes greater if the number of divisions is increased. Further, the tension of the release film 2 between the release film supply units 3a and 3b and the heating rolls 5a and 5b, and between the heating rolls 4a and 4b and the cooling rolls 5a and 5b is 1000 g / m in the present embodiment. Needless to say, the smaller the tension is, the more effective it is in preventing the deformation of the prepreg sheet 1.

Further, by attaching the torque adjusting device to the cooling rolls 5a and 5b, no matter how the heating conditions of the heating rolls 4a and 4b are changed, the gap between the heating rolls 4a and 4b and the cooling rolls 5a and 5b is changed. The tension was stabilized and the prepreg sheet 1 to which the release film 2 was adhered did not have any slack. Even if metal rolls are used as the heating rolls 4a and 4b, the tension is constant and the cooling rolls 5a and
It has been confirmed that even if the pressure of 5b is increased, a part of the release film 2 of the prepreg sheet 1 is not peeled off after passing through the cooling rolls 5a and 5b.

Next, circuit boards on both sides were manufactured using the prepreg sheet 1 having the releasable film 2 adhered to the front and back by the above method. Since the method of manufacturing the circuit boards on both sides is the same as that of the conventional example, the description thereof is omitted here.

In the circuit boards on both sides obtained by the manufacturing method of the present invention, the deformation of the prepreg sheet 1 is drastically reduced, and the focus of the laser is not deviated in the formation of the through hole by the laser processing, so that the stable hole shape is obtained. At the same time, it was confirmed that the slit 10 dividing the releasable film 2 had no problem in laser processing and conductive paste printing, and the connection resistance was stable.

(Third Embodiment) The process of adhering the prepreg sheet and the release film in the method for manufacturing a circuit board according to the third embodiment of the present invention will be described below. The laminator shown in FIG. 1 used in the second embodiment. This will be described with reference to the configuration and the sectional view of the bonding step. Detailed description of the same parts as those in the first embodiment will be omitted.

In FIG. 1, reference numeral 1 denotes a prepreg sheet having a thickness of 200 to 300 μm, which is made of a composite material obtained by impregnating a non-woven aromatic polyamide fiber with a thermosetting epoxy resin and having pores inside and processed into a 500 mm square. 2 is a roll-shaped release film having a width of 550 mm and a thickness of 12 μm. Releasable film supply units 3a and 3b are arranged above and below the laminator, and a free roll 11, a releasable film cutting unit 8, a free roll 11, heating rolls 4a and 4b are arranged in the traveling direction of the release film 2. Cooling roll 5a,
5b are arranged in the order of upper and lower, and the heating rolls 4a, 4
A loading section 6 for the prepreg sheet 1 is provided on the loading side of b, and a removal section 7 is provided behind the cooling rolls 5a and 5b.
When static electricity is generated due to the adhesion of the prepreg sheet 1 and the release film 2, a static electricity removing device may be provided behind the cooling rolls 5a and 5b.

The releasable film cutting section 8 is composed of a rod to which five cutter knives 9 are attached at a pitch of about 90 mm width and a holding section (not shown), which is detachable and has a set slit 10 length. The knife 9 is structured to rotate so as to separate from the release film 2. When the rod is attached to the holding portion in a state in which the release film 2 of the upper and lower release film supply portions 3a and 3b can pass through the free roll 11, the heating rolls 4a and 4b, and the cooling rolls 5a and 5b to be bonded, As shown in FIG. 2, the release film 2
Is slitted into a width of about 90 mm and has five slits 10 having a constant length and sent to the heating rolls 4a and 4b. In the example, for the length of the prepreg sheet 1 of 500 mm,
The length of the slit 10 was also 500 mm. Heating roll 4
The surface temperature of a and 4b is controlled at 120 ℃,
Pressurized with an air pressure of 2.0 Kg / cm ² . The feed speed is set to 2 m / min.

The cooling rolls 5a and 5b are pressurized with an air pressure of ² kg / cm ² , and the feeding speed is set to be about 20% faster than the heating rolls 4a and 4b without setting the release film 2 or the prepreg sheet 1. A torque control device (not shown) is provided on the cooling roll 4b that controls rotation, and
The structure is such that a constant tension of 000 g / m works. In addition, the releasable film supply units 3 a and 3 b and the heating roll 4
The tension of the release film 2 between a and 4b is 1000 g / m.
And

The release film 2 and the prepreg sheet 1 are adhered to each other as follows.

Only the releasable film 2 of the releasable film supply portions 3a and 3b arranged in advance above and below is taken out by passing the heating rolls 4a and 4b and the cooling rolls 5a and 5b in a state where the release agent coating surface is in contact. When the release film cutting portion 8 is attached in a state where the release roller 2 is protruded to an appropriate amount, the release film 2 is divided into slits 10 having a pitch of about 90 mm and a length of 500 mm, and the heating roll 4 is divided.
a, 4b. Then, when the prepreg sheet 1 is charged from the charging section 6 to the rotating section of the heating rolls 4a, 4b, it passes through the heating rolls 4a, 4b and the cooling rolls 5a, 5b and is melted by heating and pressurizing.
The releasable film 2 divided by the resin component is adhered and discharged to the take-out section. When the prepreg sheet 1 is loaded into the heating rolls 4a and 4b from the loading section, a part of the prepreg sheet 1 on the bonding start side is bonded to the part of the release film 2 without the slits 10 as shown in FIG. The input timing of 1 is shifted. Two
If the prepreg sheets 1 are sequentially put into the rotating portions of the heating rolls 4a and 4b from the feeding portion 6 in the same manner, the second and subsequent sheets can be continuously bonded.

200 pieces of 500 mm square prepreg sheets 1 were continuously adhered by the method of this embodiment, but the deformation of the prepreg sheet 1 due to the tension of the release film 2 was suppressed to a level at which there was no problem in defocusing during laser processing. , Stable adhesion could be performed continuously without breakage.

Further, the slit 10 of the second embodiment is continuous, whereas the slit 10 of the third embodiment has a constant length,
Moreover, since a part of the prepreg sheet 1 on the bonding start side is bonded to the part of the release film 2 without the slit 10 as shown in FIG. 5, in the peeling step of the release film 2 in the method for manufacturing a circuit board, In the second embodiment, the number of times of peeling increases depending on the number of divisions, whereas in the third embodiment, peeling is started at a portion where the slit 10 does not exist, so that peeling can be performed simultaneously regardless of the number of divisions.

Using the prepreg sheet 1 to which the release film 2 is adhered in this embodiment, the obtained circuit boards on both sides are greatly reduced in deformation of the prepreg sheet 1 as in the second embodiment. A stable hole shape is obtained by eliminating the focus deviation of the laser in forming the through hole, and the slit 10 that divides the release film 2 has no problem for the laser processing and the conductive paste printing process.
It was confirmed that the connection resistance was stable.

In the second and third embodiments, the prepreg sheet 1 cut to a predetermined size is fed at a constant interval to bond the release film, but the prepreg sheet is bonded as in the first embodiment. When charging to the heating roll from the charging part,
The same effect can be obtained even if a part of the prepreg sheets are overlapped with each other to be in a continuous state.

In the second and third embodiments, the laminator is composed of a pair of heating rolls and a pair of cooling rolls.
After making the speed of the cooling roll faster than the feeding speed of the heating roll, a torque adjusting device is provided on the cooling roll side that controls the rotation, but even if it is composed of a plurality of pairs of heating rolls and cooling rolls, By increasing the speeds of the second and subsequent heating rolls and cooling rolls higher than the feed speed of the first heating roll, and by attaching the torque adjusting device to all the rolls on the side that controls the feeding speed of the first and later heating rolls. It can be easily guessed that the tension between the rolls can be made constant.

In the first, second and third embodiments, the double-sided circuit boards are described, but the release film 2 is adhered to the front and back surfaces of the prepreg sheet 2 to be used as a mask when the conductive paste is filled. It goes without saying that the present invention can also be applied to the above circuit board.

In the first, second and third embodiments, the prepreg sheet 1 in which the nonwoven fabric is impregnated with the thermosetting resin is used, but the prepreg sheet 1 in which the woven fabric is impregnated with the thermosetting resin is used. Similar results are obtained even when used.

Although polyethylene terephthalate is used as the base film of the releasable film 2 in the first, second and third embodiments, the same effect can be obtained by using polysulphenylene sulfide, polyimide or polyethylene naphthalate. Is getting

[0054]

According to the present invention, in the first method, the prepreg sheet can absorb the influence of the shrinkage force of the release film after heating by heating the prepreg sheets in a state where some of them are overlapped with each other. The deformation of the prepreg sheet can be suppressed only to the final prepreg sheet.

In the second method, the release film is divided and then heated to bond with the prepreg sheet.
Since the amount of contraction due to the tension or heat shrinkage of the release film can be reduced according to the number of divisions of the release film, the deformation of the prepreg sheet can be further suppressed.

In the third method, a part of the releasable film is divided into an arbitrary number with a predetermined length, and then the undivided part of the releasable film is provided on the front and back input ends of the prepreg sheet. By positioning and heating to bond,
Similar to the second method, not only the deformation of the prepreg sheet is suppressed but also the release film can be peeled off only once, regardless of the number of divisions.

Further, in the circuit board manufacturing apparatus of the present invention, since the prepreg sheet heated by the heating means is cooled and the prepreg sheet is sent at a faster speed than the heating means, the releasable film is provided. Since a constant tension can be applied to the prepreg sheet, it is possible to eliminate creases in the prepreg sheet and defective peeling of the release film due to the tension, and it is possible to set a wide range of heating and pressing conditions.

As described above, according to the present invention, the deformation of the prepreg sheet can be suppressed and the wrinkles of the prepreg sheet and the peeling failure of the release film can be eliminated. Therefore, the release film and the prepreg sheet can be stably provided. Since they can be adhered to each other, defocusing during laser processing is eliminated during the circuit board manufacturing process, and the hole shape is stable, so that a high-quality circuit board with stable connection resistance can be obtained.

[Brief description of drawings]

FIG. 1 is a plan view after a prepreg sheet and a release film are adhered to each other in a first embodiment of the present invention.

FIG. 2 is a front view of a bonding step in second and third embodiments of the present invention.

FIG. 3 is a plan view showing the periphery of the release film cutting portion after the release film cutting portion is attached.

FIG. 4 is a plan view of a prepreg sheet and a release film according to a second embodiment of the present invention after being bonded.

FIG. 5 is a plan view after a prepreg sheet and a release film are adhered to each other in a third embodiment of the invention.

FIG. 6 is a process cross-sectional view showing a method for manufacturing a double-sided circuit board.

FIG. 7 is a front view of a schematic configuration of a laminator and a bonding process.

FIG. 8 is a plan view showing deformation of a prepreg sheet after conventional release film adhesion.

FIG. 9 is a plan view showing slack when a conventional release film and a prepreg sheet are bonded together.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Prepreg sheet 2 Releasable film 4a, 4b Heating roll 5a, 5b Cooling roll 7 Extraction part 8 Releasable film cutting part 22 Through hole 23 Conductive paste 24 Metal foil

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location H05K 3/46 H05K 3/46 T (72) Inventor Kunio Kishimoto 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita (72) Inventor Toshihiro Nishii 1006 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (8)

[Claims] 1. A prepreg sheet provided with a releasable film having releasability on the front and back sides is provided with a through hole, the through hole is filled with a conductive paste, and the releasable film is peeled off. A method of manufacturing a circuit board in which the front and back of a board are electrically connected by heating and pressing a foil and a circuit is further formed by etching, wherein a part of a plurality of prepreg sheets when previously adhering a prepreg sheet and a release film. And a method for manufacturing a circuit board in which the release film is heated and adhered to the front and back of the prepreg sheet. 2. A prepreg sheet provided with a releasable film having releasability on the front and back sides is provided with a through hole, the through hole is filled with a conductive paste, and the releasable film is peeled off. A method of manufacturing a circuit board in which a metal foil is heated and pressure-welded to electrically connect the front and back sides of the board to each other to form a circuit by etching, wherein when the prepreg sheet and the releasable film are bonded, the releasability is A method for manufacturing a circuit board in which a film is divided into an arbitrary number and then heated and bonded. 3. A prepreg sheet provided with a releasable film having releasability on the front and back sides is provided with a through hole, the through hole is filled with a conductive paste, and the releasable film is peeled off. A method of manufacturing a circuit board in which a metal foil is heated and pressure-welded to electrically connect the front and back sides of the board to each other to form a circuit by etching, wherein when the prepreg sheet and the releasable film are bonded, the releasability is After dividing a part of the film into an arbitrary number with a predetermined length, position it so as to bond the undivided part of the release film to the input end of the front and back of the prepreg sheet, heat and bond Circuit board manufacturing method. 4. The method for manufacturing a circuit board according to claim 1, wherein the prepreg sheet is a woven cloth, a nonwoven cloth, or a composite material of a woven cloth and a thermosetting resin. 5. The method for manufacturing a circuit board according to claim 1, wherein the prepreg sheet is porous. 6. The method for producing a circuit board according to claim 1, wherein the base film of the release film is polyethylene terephthalate, polyphenylene sulfide, polyimide or polyethylene naphthalate. 7. A prepreg sheet provided with a releasable film having releasability on the front and back sides is provided with a through hole, the through hole is filled with a conductive paste, and the releasable film is peeled off. In a manufacturing apparatus of a circuit board for electrically connecting the front and back of the substrate by heating and pressing the foil to further form a circuit by etching, heating means for heating and sending the prepreg sheet provided with the release film,
A cooling means for cooling the prepreg sheet heated by the heating means and sending the prepreg sheet at a faster speed than the heating means; and a take-out section for taking out the prepreg sheet cooled by the cooling means. Circuit board manufacturing equipment. 8. A cutting part for cutting the release film is provided,
8. The circuit board manufacturing apparatus according to claim 7, wherein the heating means heats the prepreg sheet provided with the release film cut by the cutting section.