JP2803579B2 - Circuit board manufacturing method and manufacturing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In recent years, as electronic devices have become smaller and higher in density, there has been a strong demand for multilayer circuit boards not only for industrial use but also for consumer use.

In such a circuit board, a connection method for connecting an inner via hole between a plurality of circuit patterns and a highly reliable structure are required.

The inner via hole is formed by a plating method or a filling method using a conductive paste. In the conductive paste charging method, a plastic film having a release layer formed on both surfaces of a prepreg sheet is bonded, and the inner via hole is formed via the plastic film. And a conductive paste is filled using a plastic film as a mask.

[0005] The bonding between the plastic film and the prepreg sheet is performed by simultaneously bonding the plastic film during the production of the prepreg sheet (for example, JP-A-61-290).
No. 610), the present invention relates to a method for bonding a plastic film to a finished prepreg sheet.

Hereinafter, a description will be given of a bonding step between a prepreg sheet and a plastic film in a conventional circuit board manufacturing method.

For bonding the prepreg sheet and the plastic film, a commonly used laminator for photosensitive dry film lamination is used, and two pairs of heating rolls having a pressurizing means and a plastic film supply means are used. Material supply means.

FIG. 6 is a cross-sectional view showing a roll configuration of a laminator used for bonding a prepreg sheet and a plastic film and a bonding process.

[0009] 1 is, for example, a 500 mm square formed of a composite material having non-woven aromatic polyamide fibers impregnated with a thermosetting epoxy resin and having pores therein.
An aramid-epoxy sheet (prepreg sheet) having a thickness of 0 to 300 μm is provided. Reference numeral 2 denotes a roll-shaped PET film (plastic film) having a width of 550 mm and a thickness of 10 μm, which is coated with a Si-based release agent on one surface.

The roll-shaped PET film 2 is attached to the PET film supply sections 7a and 7b disposed above and below the laminator so as to sandwich the aramid-epoxy sheet 1 on the release agent application surface side.

A first heating roll 3 and a second heating roll 4 are sequentially arranged on both sides of the sheet 1 in the running direction of the PET film, and an aramid-epoxy sheet 1 is provided in front of the first heating roll 3. Of the second heating roll 4
Is provided with a take-out portion 9 behind.

The first and second heating rolls 3 and 4
This is a roll having a diameter of 80 mm and a length of 700 mm, in which a 5-mm thick metal roll is lined with heat-resistant silicon rubber having a thickness of 5 mm and a rubber hardness of 70 degrees.

The surface temperature of the first heating roll 3 is set to 100
℃, the surface temperature of the second heating roll 4 is controlled to 120 ℃, the first heating roll 3 and the second heating roll 4
Are pressurized with an air pressure of ² kg / cm ² . The laminating speed is 2 m / min.

The bonding between the PET film 2 and the aramid-epoxy sheet 1 is performed only by placing the first and second heating rolls 3 and 4 in contact with only the PET film 2 disposed in advance and vertically in contact with the release agent application surface. And the aramid-epoxy sheet 1 is fed into the rotating part of the first heating roll 3 from the feeding part 8 in a state where the sheet is protruded from the loading part 9 by an appropriate amount, and the first heating roll 3 and the second heating roll 4 To soften the resin component of the aramid-epoxy sheet 1 and adhere by pressing.

The second and subsequent sheets are aramid-epoxy sheets 1
Are sequentially fed from the supply unit 8 to the rotating unit of the first heating roll 3 so that continuous bonding can be achieved.

Using the aramid-epoxy sheet 1 with the PET film 2 adhered to the front and back by the above-described method, a method for manufacturing a double-sided circuit board as a base for multilayering will be described.

FIGS. 7A to 7F are process sectional views showing a method for manufacturing a double-sided circuit board. First, an aramid-epoxy sheet 1 to which a PET film 2 is adhered (FIG. 7)
As shown in FIG. 7B, through holes 22 are formed at predetermined locations in FIG. 7A by using a laser processing method or the like.

Next, as shown in FIG.
Is filled with a conductive paste 23. Conductive paste 2
As a method of filling 3, the aramid-epoxy sheet 1 having the through holes 22 is placed on a table of a printing machine (not shown), and the conductive paste 23 is printed directly on the PET film 2.

At this time, the PET film 2 on the upper surface plays a role of a printing mask and a role of preventing contamination of the surface of the aramid-epoxy sheet 1.

Next, as shown in FIG.
The PET film 2 is peeled off from both sides of the epoxy sheet 1.

Next, as shown in FIG.
A metal foil 24 such as a copper foil is attached to both surfaces of the epoxy sheet 1. By heating and pressing with a hot press in this state, the thickness of the aramid-epoxy sheet 1 is compressed (t1> t2) as shown in FIG. Are adhered.
At this time, the resin component of the aramid-epoxy sheet 1 is cured by heating.

Then, the metal foil 24 on the front and back sides is selectively etched to form a circuit pattern, and a circuit board on both sides is obtained.

As described above, in the manufacture of the circuit board, the PET film adhered to the front and back of the aramid-epoxy sheet has through holes formed by laser processing or the like, and is used as a mask when printing the conductor paste. It is peeled off after printing.

For miniaturization of a circuit board, a PET film is uniformly adhered to an aramid-epoxy sheet surface, does not peel off during laser processing or printing of a conductive paste, and the conductive paste spreads over a required area when the conductive paste is filled. It is important that nothing is done.

In addition, during laser processing, if the workpiece is undulated, the focus shifts and a stable hole shape cannot be obtained. Therefore, it is important to bond the plastic film without deforming the prepreg sheet. .

[0026]

However, in the above-mentioned conventional construction, the plastic film and the sheet 1 are adhered or adhered to each other by the first heating roll having a low temperature, and are applied by the second heating roll having a high temperature. Due to the pressure, it is difficult to completely spread and adhere the plastic film contracted by the temperature of the second heating roll by the second heating roll, and wrinkles of the plastic film occur.

Since tension is applied to the plastic film in the traveling direction, thermal contraction in the traveling direction is absorbed by the tension, and only the apparently free lateral direction thermally contracts.
The excess plastic film that cannot be spread by the second heating roll is wrinkled.

When the conductive paste is filled into the wrinkled through-hole with the conductive paste, the conductive paste enters the gap between the prepreg sheet and the plastic film, and the diameter of the through-hole becomes apparently large. There was a problem of short-circuiting with adjacent through holes.

Since the prepreg sheet is softened immediately after bonding with the second heating roll, the prepreg sheet is not sent to the take-out portion due to static electricity generated when the second heating roll is pressurized or the tackiness of the rubber roll. There was a problem that stable continuous bonding could not be performed due to winding around the heating roll of No. 2.

Further, since the plastic film is adhered to the prepreg sheet while applying tension, the contraction stress acts on the plastic film when the tension is released after the adhesion, so that both ends of the plastic film and the prepreg sheet are moved in the traveling direction. Wrinkles occur in the horizontal direction.

The step due to the wrinkles of the prepreg sheet causes a problem in that the focus shifts during laser processing, the hole diameter varies, and the connection resistance becomes unstable.

The present invention solves the above-mentioned conventional problems, and a method of manufacturing a circuit board for realizing a high-performance, high-quality circuit board by continuously bonding a plastic film to a prepreg sheet with high quality. It is intended to provide.

[0033]

In order to achieve the above object, a method of manufacturing a circuit board according to the present invention comprises the steps of: preventing wrinkling of a plastic film and winding of a prepreg sheet by a first heating roll; After the plastic film is passed through the front and back surfaces of the prepreg sheet without bonding, the plastic film is bonded to the front and back surfaces of the prepreg sheet by a second heating roll, and then passed through a take-out roll having no heating means and a static electricity removing section.

150 ° C. of the above plastic film 30
The heat shrinkage rate during minute heating is desirably 0.5% or less, and the heat shrinkage rate is stabilized by applying a heat treatment after applying the release agent to the plastic film.

In order to prevent wrinkles of the prepreg sheet, the value of the plastic film protruding from the prepreg sheet is preferably set to 10 mm or less on one side. When the plastic film is made smaller than the prepreg sheet, in order to prevent the resin component of the prepreg sheet from adhering to the heating roll, the plastic film is cut into a predetermined size in the width direction before passing through the first roll, and the unnecessary portion of the cut plastic film is cut. After passing through the first heating roll and the second heating roll for bonding while leaving the plastic film, the unnecessary portion of the plastic film may be removed. It is preferable that a cut portion of the plastic film is provided between the roll and the roll, and a peeling portion and a winding portion of the cut plastic film are provided behind the second heating roll or the take-out roll.

[0036]

According to the present invention configured as described above, the first
Since the prepreg sheet and the plastic film pass through the heating roll without bonding, the degree of freedom of the plastic film increases, and the plastic film that contracts due to temperature when bonded by the second heating roll is spread by the second heating roll. Can be adhered, and the generation of wrinkles can be eliminated.

Further, by reducing the heat shrinkage of the plastic film due to the temperature, the shrinkage of the plastic film at the time of bonding with the second heating roll can be reduced, and the condition range in which wrinkles do not occur is widened, thereby facilitating the production. . Further, the heat shrinkage of the plastic film can be stabilized by reducing the residual stress due to the tension applied in the process of applying the plastic film or the release agent by heat-treating the plastic film.

Further, by providing a take-out roll having no heating means and a static electricity removing section behind the second heating roll, the prepreg sheet is cooled to increase rigidity, so that winding around the roll is eliminated, and the next static electricity is removed. Since the static electricity is removed in the removing section, continuous feeding of the prepreg sheet is possible.

Also, the value of the plastic film that protrudes from the prepreg sheet is set to 10 mm or less on one side to reduce the amount of the free plastic film, thereby reducing the function of the shrinkage stress of the plastic film generated at both ends of the prepreg sheet when the tension is released. The generation of wrinkles in the prepreg sheet can be prevented.

When the prepreg sheet is smaller than the prepreg sheet, the resin component of the prepreg sheet adheres to the second heating roll having a high temperature, and it is necessary to periodically wipe the resin component. By cutting through the first heating roll and the second heating roll and bonding while leaving the unnecessary portion of the plastic film cut, thereby minimizing the resin protrusion of the prepreg sheet. 2, the amount of adhesion to the heating roll can be reduced and the number of times of wiping can be reduced.

Unnecessary plastic films can be easily removed even after bonding since a release agent is applied to the surface to be bonded to the prepreg sheet.

Further, in the apparatus for manufacturing a circuit board, a plastic film cutting means is provided between the plastic film supply means and the first heating roll to cut the plastic film to a predetermined size, and the second heating roll By providing the plastic film winding portion cut at the rear, the resin component of the prepreg sheet is prevented from adhering to the second heating roll, and stable continuous bonding can be performed without lowering the productivity.

[0043]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The process for bonding a prepreg sheet and a plastic film in a method of manufacturing a circuit board according to an embodiment of the present invention will be described below.

(First Embodiment) FIG. 1 is a sectional view showing a roll configuration of a laminator used for bonding a prepreg sheet and a plastic film according to a first embodiment of the present invention, and a bonding process.

1 has a thickness of 20 mm and is made of a composite material having pores therein and impregnated with, for example, an aromatic polyamide fiber of a nonwoven fabric and having a thermosetting epoxy resin.
It is an aramid-epoxy sheet (prepreg sheet) of 0 to 300 μm.

Reference numeral 2 denotes a roll-shaped PET film (plastic film) having a width of 510 mm and a thickness of 10 μm coated with a Si-based release agent on one side. , Which had a heat shrinkage of 0.1% (at 150 ° C. for 30 minutes).

The PET film supply units 7a and 7b disposed above and below the laminator are provided with a roll-shaped PET film 2.
Holds the aramid-epoxy sheet 1 on the release agent application surface side, so that the upper PET supply unit 7a has the release agent application surface on the upper side, and the lower PET supply unit 7b has the release agent application surface on the lower side. Is installed.

The first heating roll 3, the second heating roll 4, the take-out roll 5, and the static elimination blower 6 are sequentially arranged in the traveling direction of the PET film 2.
, A prepreg sheet input section 8 is provided on the input side of the first heating roll 3, and a take-out section 9 is provided behind the static elimination blower 6.

The first heating roll 3 is made of a metal roll of φ70 mm lined with heat-resistant silicon rubber having a rubber hardness of 70 degrees. The convex portions 10 at both ends are φ80.5 mm, and the concave portions are φ80.5 mm.
0 mm, a 700 mm long roll with a step as shown in FIG. 2, the surface temperature is controlled to 100 ℃,
It is pressurized with an air pressure of 0.5 kg / cm ² .

The second heating roll 4 is a roll having a diameter of 80 mm and a length of 700 mm obtained by lining a heat-resistant silicon rubber having a rubber hardness of 70 degrees on a metal roll having a diameter of 70 mm.
The surface temperature is controlled at 120 ° C and 1 kg / cm
It is pressurized by the air pressure of ² .

The take-out roll 5 is a roll of a φ30 mm metal roll lined with heat-resistant silicon rubber having a rubber hardness of 40 degrees and having no φ40 mm and 700 mm length heating means.

The peripheral speed of each roll for transporting the film 2 is the same, and is set at 2 m / min.

The bonding by the laminator is performed as follows. First, only the PET film 2 which has been previously arranged vertically is passed through the first heating roll 3, the second heating roll 4, the take-out roll 5, and the static elimination blower 6 in a state where the release agent-coated surface is in contact with the PET film 2, and the take-out section 9 At a speed of 2 m / min.

Next, the aramid epoxy sheet is supplied to the charging section 8.
From the first heating roll 3, the PET film 2 and the aramid epoxy sheet 3 pass through the first heating roll 3 without being bonded, and the aramid-epoxy sheet 1 passes through the second heating roll 4. Is softened and adhered by pressing.

Thereafter, the sheet is passed through a take-out roll 5 having no heating means and a static elimination blower 6 and taken out to a take-out section 9.

The first heating roll 3 weighs about 20 kg, and even if the air pressure is 0 kg / cm ² and the film 2 and the sheet 1 are pressed by the roll's own weight, the contact area between the rolls when pressed is large. The aramid epoxy sheet 1 and the PET film 2 adhere to each other due to the increase in the tackiness of the rubber roll and the generation of static electricity.

For this reason, in the present embodiment, 500 μm convex portions 10 are provided at both ends of the first heating roll 3, and pressure is applied using the concave portions so that the pressure applied to the aramid epoxy sheet 1 and the PET film 2 by the roll's own weight is reduced. Fine adjustment is possible and the generation of static electricity is suppressed to prevent adhesion.

The aramid epoxy sheet 1 immediately after bonding is soft due to high temperature, and is tightly wound around the upper or lower second heating roll 4 due to static electricity generated during bonding and the tackiness of the roll. The aramid-epoxy sheet 1 is passed through a take-out roll 5 which increases the rigidity of the aramid epoxy sheet 1 and has a large curvature to make it difficult to wind. Has been prevented.

At this time, the rubber hardness of the take-out roll 5 is set to 3
If the value is set to 0 or less, when the PET sheet 2 alone passes through the take-out roll 5, the take-up roll 5 is wrapped. When the rubber hardness exceeds 60, the pressure of the roll becomes non-uniform, and it becomes impossible to feed stably. Before the static elimination blower 6 was installed, the static electricity exceeded 10 KV, and discharge to the human body was observed.

After the second sheet, the aramid-epoxy sheet 1 can be continuously adhered by sequentially feeding the aramid-epoxy sheet 1 from the charging section 8 to the rotating section of the first heating roll 3.

Using the manufacturing method of this embodiment, a 500 mm
1000 pieces of the aramid-epoxy sheet were continuously adhered to the corner, but all of the aramid-epoxy sheet and the plastic film were free of wrinkles and stable adhesion was continuously performed.

Table 1 shows the results when PE films adhered to an aramid epoxy sheet using PET films having different heat shrinkage rates.
The result of wrinkling of the T film is shown. The number of samples is 5 for each condition.

When the heat shrinkage ratio exceeds 0.5%, wrinkles which cause the conductive paste to run out during filling of the conductive paste to be performed later occur. It was also found that the higher the heat shrinkage, the greater the degree of wrinkling.

As a result of the experiment, the inventor found that the heat shrinkage ratio was 0.1%.
It was confirmed that when the content was 5% or less, adhesion without wrinkling of the PET film was possible.

[0065]

[Table 1]

Table 2 shows the heat shrinkage before and after the PET film was heat-treated at a temperature of 140 ° C. for 5 minutes.

The variation in the heat shrinkage of the PET film is as follows:
It was confirmed that this was an effective means for reducing the heat shrinkage rate and stabilizing the heat shrinkage by reducing the heat treatment to 0.5% or less in all cases.

[0068]

[Table 2]

Table 3 shows the results of wrinkling of the aramid epoxy sheet according to the amount of protrusion of the plastic film for the aramid epoxy sheet having a width of 500 mm. A plastic film having a heat shrinkage of 0.5% was used, and the number of samples was set to 5 under each condition.

When the protrusion of the PET film is 10 mm or less on one side, no wrinkles are formed on the aramid epoxy sheet to affect the hole shape in the subsequent laser processing. It was found that by setting the thickness to 520 mm or less, which is 20 mm larger than the width of the aramid epoxy sheet, it is possible to stably obtain an aramid epoxy sheet without wrinkles.

[0071]

[Table 3]

Next, a double-sided circuit board was manufactured using an aramid-epoxy sheet having a PET film adhered to the front and back sides by the method described above. The manufacturing method of the circuit boards on both sides is the same as that of the conventional example, and the description is omitted here.

The circuit board on both sides thus obtained has no wrinkles in the PET film used as a mask when printing the conductive paste in the through-holes, and is uniformly adhered to the aramid-epoxy sheet. There was no occurrence of a short circuit phenomenon between adjacent patterns and adjacent through holes generated when the paste was contained in the through holes and entered the gap between the aramid-epoxy sheet and the PET film.

Further, the step caused by wrinkles of the prepreg sheet was eliminated, the focal point became constant during laser processing, a stable hole diameter was obtained, and the connection resistance was stabilized.

(Second Embodiment) Hereinafter, a description will be given of a bonding step between a prepreg sheet and a plastic film in a method of manufacturing a circuit board according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a roll configuration of a laminator used for bonding a prepreg sheet and a plastic film and a bonding process.

1 is, for example, a 500 mm square formed of a composite material having non-woven aromatic polyamide fibers impregnated with a thermosetting epoxy resin and having pores therein, and having a thickness of 20 mm.
It is an aramid-epoxy sheet (prepreg sheet) of 0 to 300 μm.

Reference numeral 2 denotes a roll-shaped PET film (plastic film) having a width of 550 mm and a thickness of 10 μm, to which a Si-based release agent is applied on one side.

The PET film supply units 7a and 7b arranged above and below the laminator are provided with a roll-shaped PET film 2
Because the aramid-epoxy sheet 1 is sandwiched between the release agent application surfaces, the upper PET supply unit 7a has the release agent application surface on the upper side, and the lower PET supply unit 7b has the release agent application surface on the lower side. Attached.

Then, the PET film cutting section 11, the first heating roll 3, and the second
The heating roll 4, the take-out roll 5, and the static elimination blower 6 are arranged vertically in this order, and the charging section 8 of the prepreg sheet 1 is disposed on the charging side of the first heating roll 3.
A peeling portion 12 of the unnecessary PET sheet 13 and a take-out portion 9 are provided at the rear of the unnecessary PET film 13. Unnecessary PET film 12 peeled off by the peeling portion 12 is wound below a take-out portion 9 via a free roll. A take-out part 14 is provided.

The PET film cutting section 11 is composed of a rod having two cutter knives attached at a pitch width of 490 mm in a direction perpendicular to the paper surface and a holding section, and has a detachable structure (not shown).

This rod connects the PET films 2 of the upper and lower PET film supply units 7a, 7b to the first heating roll 3,
As shown in FIG. 4, when the second heating roll 4, the take-out roll 5, and the neutralizing blower 5 are attached to the holding unit in a state where they can be adhered, the PET film 2 has a thickness of 49 mm.
A slit 15 having a width of 0 mm is formed, and the film 2 has a film portion having a width of 490 mm at the center and 30 mm at both ends thereof.
The film is cut and divided into a total of three ((550-490) / 2 = 30) film portions, and is sent to the first heating roll 3.

As shown in FIG. 5, the peeling portion 12 of the unnecessary PET sheet 13 having a width of 30 mm at both ends is attached to a free roll attached to the rear of the take-out roll 5 so as to be substantially the same height as the aramid-epoxy sheet 1. -Providing two protrusions for peeling off the unnecessary PET sheet 13 at a position wider than the width of the epoxy sheet 1, and the unnecessary PET sheet 13 is pulled via the intermediate free roll 16 by rotating the winding unit 14, Peel off.

In the embodiment, the peeling portion 12 is taken out and the roll 6 is taken out.
Although provided on the rear side, the same result is obtained even when provided on the rear side of the second heating roll.

Rolling-up part 14 of unnecessary PET film 13
Is φ80 mm and the rotation speed is the first heating roll 3,
It is synchronized with the second heating roll 4 and the take-out roll 5, but as the winding amount increases, the speed increases and the tension increases, so that a structure (not shown) slips when a torque exceeding a certain level is applied. I have.

The first heating roll 3 has a metal roll of φ70 mm lined with heat-resistant silicon rubber having a rubber hardness of 70, the convex portions 10 at both ends are φ80.5 mm, and the concave portions are φ80 m.
m, a stepped roll having a length of 700 mm as shown in FIG.
It is pressurized with an air pressure of 5 kg / cm ² .

The second heating roll 4 is a roll having a diameter of 80 mm and a length of 700 mm formed by lining a heat-resistant silicon rubber having a rubber hardness of 70 on a metal roll having a diameter of 70 mm. The surface temperature is controlled at 120 ° C., and 1 kg / cm ² . It is pressurized with air pressure.

The take-out roll 5 is a roll having a diameter of 40 mm and a length of 700 mm obtained by lining a heat-resistant silicon rubber with a rubber hardness of 40 degrees on a metal roll of φ30 mm, and has no heating means.

The rotation speed of each roll was 2 m / m
set to in. Adhesion by this laminator is performed as follows. A PET film cutting unit 1 is attached to the PET film 2 discharged from the PET sheet supply units 7a and 7b.
The first heating roll 3, the second heating roll 4, and the take-out roll 4 are provided with slits 15 having a width of 490 mm and the PET film 2 having the unnecessary PET films 13 on both sides remaining in contact with the release agent application surface. 5. Pass through the static elimination blower 6 in order.

Next, the PET film 2 to be adhered to the aramid-epoxy sheet 1 is sent to the take-out section 9, and the unnecessary PET film 13 is sent to the winding section 14 via the peeling section 12 and the free roll 16 at a speed of 2 m / min. In this case, the aramid-epoxy sheet 1 is fed from the feeding section 8 to the rotating section of the first heating roll 3.

Then, when passing through the first heating roll 3, the PET film 2 and the unnecessary PET film 1
3 and the aramid epoxy sheet 1 are not bonded,
In the heating roll 4, the resin component of the aramid-epoxy sheet 1 is softened when passing through the heating roll 4, and adheres by pressing.

The PET film 2 and the unnecessary PE
Aramid-epoxy sheet 1 with T film 13 bonded
Is sent to the take-out unit 9 through the take-out roll 5 and the charge removing blower 6.

After passing through the take-out roll 5, the unnecessary PET film 13 is separated from the peeling section 1 provided behind the static elimination blower 6.
The sheet 2 is peeled off from the aramid-epoxy sheet 1 and wound up by a winding section 14 provided below the take-out section 9 via a free roll.

After the second sheet, the aramid-epoxy sheet 1 is sequentially put into the rotating portion of the first heating roll 3 to be continuously adhered, and the unnecessary PET film 13 is wound up.

According to this embodiment, aramid of 500 mm square was used.
200 sheets of epoxy sheets were continuously bonded, but aramid-
There are no wrinkles in the epoxy sheet or plastic film,
Stable bonding was performed continuously.

The present invention is particularly effective when the width of the PET film is smaller than that of the aramid-epoxy sheet.

When the PET film is smaller than the aramid-epoxy sheet width, the resin component of the aramid-epoxy sheet is melted by the temperature of the heating roll and adheres to the roll in the conventional method.

The adhered resin component gradually accumulates and begins to harden, resulting in non-uniform pressure and foreign substances, which are mixed into the aramid-epoxy sheet, and which cause contamination of the necessary portion of the PET sheet. It was necessary to wipe with alcohol etc. at intervals of time,
In the method of the present invention, the portion where the resin component elutes into the roll is limited to the minimal portion of the slit portion, and is adhered with almost no gap. The wiping work improved.

Next, a double-sided circuit board was manufactured using an aramid-epoxy sheet having a PET film adhered to the front and back sides by the above method. The manufacturing method of the circuit boards on both sides is the same as that of the conventional example, and the description is omitted here.

The resulting double-sided circuit board has a PET film used as a mask for printing a conductive paste in the through-holes, as in the first embodiment, without wrinkles, and is uniformly adhered to the aramid-epoxy sheet. As a result, there was no occurrence of a short-circuit phenomenon between adjacent patterns and adjacent through-holes, which occurs when the conductive paste is contained in the through-holes and enters the gap between the aramid-epoxy sheet and the PET film.

Further, the step due to wrinkles of the prepreg sheet was eliminated, the focal point became constant during laser processing, a stable hole diameter was obtained, and the connection resistance was stabilized.

Although the embodiments have been described with reference to a circuit board on both sides, it goes without saying that the present invention can be applied to a multilayer circuit board used as a mask when a conductive film is filled by bonding a plastic film to the front and back of a prepreg sheet.

Although the prepreg sheet in which the non-woven fabric is impregnated with the thermosetting resin is used in the examples, the same result is obtained by using the prepreg sheet in which the woven fabric is impregnated with the thermosetting resin.

Further, although the prepreg sheet processed into a predetermined shape is used in the embodiment, similar results are obtained by using a continuous prepreg sheet.

[0105]

As described above, in the method of manufacturing a circuit board according to the present invention, the first heating roll allows the plastic film to pass through the front and back of the prepreg sheet without bonding, and the second heating roll applies the plastic film. After adhering the plastic film to the front and back of the prepreg sheet, it can be stably adhered to the plastic film without wrinkles by passing it through a take-out roll without heating means and a static elimination blower.When filling the conductive paste, the conductive paste Is prevented from entering the gap between the prepreg sheet and the plastic film, problems such as hindering miniaturization and short-circuiting with adjacent patterns and adjacent through holes are eliminated, and wrapping of the prepreg sheet around a roll is eliminated, thereby enabling continuous bonding.

Further, by making the width of the plastic film not more than +20 mm of the width of the prepreg sheet, it is possible to adhere without wrinkles to both ends of the prepreg sheet, to eliminate the step due to the wrinkles, to keep the focal point constant at the time of laser processing, and to stabilize. Thus, a high-performance and high-quality circuit board can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a main part of a laminator according to a first embodiment of the present invention.

FIG. 2 is a front view showing a first heating roll in the embodiment.

FIG. 3 is a sectional view showing a main part of a laminator according to a second embodiment of the present invention.

FIG. 4 is a plan view showing the vicinity of the PET sheet cutting portion after the PET sheet cutting portion is attached in the embodiment.

FIG. 5 is a plan view showing the periphery of a PET sheet and a winding section in the embodiment.

FIG. 6 is a cross-sectional view showing a main part of a laminator used for bonding a pre-breg sheet and a plastic film in a conventional example.

FIG. 7 is a sectional process view showing a method for manufacturing a conventional double-sided circuit board.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 aramid-epoxy sheet (prepreg sheet) 2 PET film (plastic sheet) 3 first heating roll 4 second heating roll 5 take-out roll 6 static elimination blower 7 PET sheet supply section 8 input section 9 take-out section 10 convex section 11 PET sheet cutting part 12 Peeling part 13 Unnecessary PET sheet 14 Winding part 15 Slit 21 Aramid-epoxy 22 Through hole 23 Conductive paste 24 Metal foil

──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shinji Nakamura 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Kunio Kishimoto 1006 Kadoma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Toshihiro Nishii 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-3-7325 (JP, A) JP-A-2-84318 (JP, A) JP-A-63-155793 (JP, A) JP-A-63-59517 (JP, A) JP-A-1-225395 (JP, A) JP-A-4-37537 (JP, A) JP-A-5-41763 (JP, U) JP 1-14016 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) H05K 3/00, 3/40, 3/42, 3/46 B29C 65 / 00-65/82

Claims (11)

(57) [Claims] 1. A prepreg sheet provided with a plastic film having releasability on both sides thereof is provided with a through hole, a conductive paste is filled in the hole, the plastic is peeled off, and then a metal foil is heated and pressed on the front and back sides of the prepreg sheet. A circuit board manufacturing method for electrically connecting the front and back of the substrate with each other and further forming a circuit by etching, wherein the plastic film and the prepreg sheet are arranged in such a manner that the plastic film sandwiches the front and back of the prepreg sheet. The plastic film and the prepreg sheet arranged as described above are paired with a pair of first
By preheating without adhering the plastic film and the prepreg sheet, and then passing between a pair of second heating rolls set at a predetermined temperature and pressure. And bonding the plastic film and the prepreg sheet. 2. A plastic film is cut into a predetermined size in the width direction before passing through the first roll, and the plastic film is passed through the first heating roll and the second heating roll while being adhered while leaving the cut unnecessary plastic film. 2. The method according to claim 1, wherein the unnecessary portion of the plastic film is removed thereafter. 3. A plastic film having a thickness of 30 ° C. at 150 ° C.
2. The method for manufacturing a circuit board according to claim 1, wherein a material having a heat shrinkage rate of 0.5% or less during minute heating is used. 4. The method for producing a circuit board according to claim 1, wherein a heat treatment is performed after applying and drying a release agent to the plastic film. 5. The method for manufacturing a circuit board according to claim 1, wherein a plastic film having a protrusion amount from a prepreg sheet of 10 mm or less on one side is used. 6. The method for manufacturing a circuit board according to claim 1, wherein a convex portion is provided at one or both ends of the first heating roll, and heating and pressing are performed at the concave portion. 7. The method for producing a circuit board according to claim 1, wherein the prepreg sheet is a composite material of a nonwoven fabric or a woven fabric and a thermosetting resin and is porous. 8. The method according to claim 1, wherein the prepreg sheet is a woven fabric or a composite material of a woven fabric and a thermosetting resin. 9. The method according to claim 1, wherein the plastic film is made of polyester terephthalate. 10. The prepreg sheet has releasability on both sides.
Rotate each other so that
A pair of first heating rolls having roll surfaces facing each other
With respect to the direction of travel of the prepreg sheet.
The prepreg sheet is provided at the back of the heat roll.
To adhere the plastic film to the back,
Of a pair of second rolls having the rotating roll surfaces thereof facing each other.
A heat roll, and the prepreg sheet is formed by the pair of first heat rolls.
A charging section for charging the plastic film between the pair of first heating rows;
From a pair of plastic film supply units
It is configured, at least one of the pair of first heating roll, before
The prepreg sheet or the plastic film
At an interval equal to or greater than the width of the heating roll in the axial direction.
And two convex portions protruding in the vertical direction are provided, and the convex portions cause the pair of heating rolls to face each other.
The gap between the roll surfaces is the same as the thickness of the prepreg sheet
Of the thickness of the plastic film
Characterized by having a laminator adjusted to
Apparatus for manufacturing a circuit board that. 11. The cutting means of the plastic film between the plastic film supply and the first heating roll is provided, the peeling of unnecessary portion and the winding portion of the plastic film cut towards after the second heating roll Claim 1 provided with
0. The apparatus for manufacturing a circuit board according to 0.