JPH04255776A - Uv curable adhesive sheet, production thereof, apparatus therefor and production of substrate for circuit board and circuit board using the same sheet - Google Patents

Abstract

PURPOSE:To obtain the title sheet suitable as a circuit board having excellent heat resistance, insulating properties, etc., by coating a specific releasable film with a viscous adhesive composition containing a specific resin, subjecting the composition to irradiation with ultraviolet ray under reduced pressure and heating. CONSTITUTION:A viscous liquid adhesive composition 4 containing a resin, preferably consisting of phenolic, epoxy, melamine, acrylic, acrylate, polyester and/or polyvinylbutral resin and being curable by ultraviolet rays is applied onto the surface of release film such as fluororesin film or polypropylene film which is not bondable to the above-mentioned resin when the resin is cured. When the composition is coated or after coating, a coating film is irradiated (and heated) with ultraviolet rays under reduced pressure preferably 60mmHg to provide the semicured objective sheet.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to an ultraviolet curable adhesive sheet, a method for manufacturing the same, an apparatus used for the manufacturing method, a method for manufacturing a circuit board substrate using the adhesive sheet, and an adhesive sheet for the same. The present invention relates to a method of manufacturing a wiring board using the method.

0002

2. Description of the Related Art In recent years, various electronic components including semiconductors have become highly integrated and miniaturized. Along with this, surface mounting technology has progressed, and printed wiring boards are now required to have even higher densities and finer patterns. To meet this demand, the selection of the manufacturing process for printed wiring boards, as well as the use of materials that have high heat resistance, high electrical insulation, and low dielectric constant, are extremely important factors.

[0003] Many manufacturing processes for printed wiring boards have been proposed so far, and among them, the so-called additive method, in which the necessary circuit conductors are formed by electroless plating, is based on thick electroless copper plating technology. This is a manufacturing process that is attracting attention as a process that is more advantageous in forming fine patterns than the subtractive method, which has been widely applied in the past. In particular, when forming small-diameter through holes, it is an essential process to obtain good reliability.
The method described on pages 73-73 is known.

This additive method includes the first method shown in FIG. 9, the second method shown in FIG. 10, or the method shown in FIGS.
The third method shown in FIG.

(1) First method In the first method, as shown in FIG. 9(a), the insulating plate 201
is used as a starting material, an adhesive 202 is applied to its surface, and as shown in FIG. 9(b), a hole is made at a desired location on the insulating plate 201 coated with this adhesive 202, and the inner wall of the hole and the adhesive are formed. The plating catalyst 204 is attached to the entire surface of the
), the entire surface is made conductive by electroless copper plating to form a copper plating film 203, and as shown in FIG.
As shown in e), after pattern electroplating is performed to form a second copper plating film 206, as shown in FIG. 9(f), the resist 205 is removed and the exposed copper plating film 203 is removed. This is a method of removing it. Because this process involves electroplating, small-diameter through-holes tend to have problems with throw-up, similar to the subtractive method. It seems that there is no particular advantage in forming fine patterns compared to the second and third methods described below.

(2) Second method As shown in FIG. 10(a), copper foil 207 and insulating plate 20
The starting material is a copper-clad laminate consisting of 1. Next, Figure 10
As shown in FIG. 10(b), holes are made at desired locations in this copper-clad laminate, and plating catalyst 204 is deposited on the inner wall of the hole and the entire surface of the laminate, and as shown in FIG. 10(c), a circuit is formed. An etching resist 215 is formed at the location shown in FIG.
As shown in FIG. 10(d), first, the front and back circuits are formed by etching, and then, as shown in FIG. 10(e), the resist 205 is
10(f), the through holes are electrolessly plated to form a copper plating film 203. This process has the following characteristics: ■
Since a copper-clad laminate with a uniform thickness is etched, circuit formation accuracy is relatively good. ■ Small diameter through hole,
The blind holes have good plating coverage. ■
Since only the plating inside the through holes is required, the burden of electroless plating is small. Items (1) and (2) above are important in forming fine patterns. A process applying this method is currently in practical use, and each company is developing materials with improved heat resistance, coefficient of thermal expansion, and dielectric constant for the starting material, copper-clad laminates. It is relatively easy to obtain printed wiring boards with excellent characteristics. However, the key point of this method is to ensure adhesion between the plating resist and the underlying circuit, and thus requires some ingenuity.

(3) Third method As shown in FIG. 11(a), an insulating plate 21 containing a plating catalyst is
Apply adhesive 202 to the surface of 1, make holes at desired locations as shown in FIG. 11(b), form resist 205 at locations that do not form a circuit, and as shown in FIG. 11(c),
After chemically roughening the surface of the adhesive 202, a copper plating film 203 is formed by electroless plating as shown in FIG. 11(d), and as shown in FIG.
Adhesive 202 is applied to the surface of 1, holes are made at desired locations as shown in FIG. 12(b), plating catalyst 204 is applied to the inner walls of the holes and the entire surface of the adhesive, and as shown in FIG. As shown in FIG. 12, there is a method in which a resist 205 is formed at a location other than the location where the circuit will be formed, and then a copper plating film 203 is formed by electroless plating, as shown in FIG. 12(d). This method is a method in which a circuit is directly formed on an insulating plate by electroless copper plating, and the characteristics are as follows. ■
It has excellent circuit formation accuracy and is suitable for forming fine circuits. ■
Good plating coverage for small diameter through holes and blind through holes. ■ It is possible to make the printed wiring board surface flat, making it suitable for surface mounting. ■ Excellent uniformity of plating film thickness and easy adjustment of line resistance. ■ The process is short, which is advantageous in reducing costs and saving resources. Although this third method is capable of achieving both fine pattern formation and cost reduction, there is a problem in that technically difficult problems must be solved in order to realize this. Currently, there is a technology that has overcome this problem and has been put into practical use. In addition, as an adhesive for such an additive wiring board, as disclosed in Japanese Patent Application Laid-Open No. 51-61958, the surface of the transfer substrate is coated with a liquid composition containing a curable resin, and then cured. adhesives are known.

[0008]

[Problems to be Solved by the Invention] In the method for manufacturing wiring boards using the additive method shown in the above-mentioned conventional technology, as the circuit becomes further finer, unevenness remains on the surface of the adhesive layer and the plating resist There was a problem in that it became difficult to form. This caused problems in plating small-diameter through-holes and plating lands for surface circuit mounting. Also,
As mentioned in the section on conventional technology, improvements in heat resistance and insulation are required in the additive method. Furthermore, chemical resistance to various processing solutions used in processing steps up to electroless plating processing is also required.

The present invention is a printed wiring board that is suitable for forming fine circuits with excellent land formation for small-diameter through-hole plating and surface circuit mounting, and is used for wiring boards that have excellent heat resistance, insulation properties, and chemical resistance. An adhesive sheet that can be used, a method for manufacturing the same, an apparatus used for manufacturing the adhesive sheet, a method for manufacturing a circuit board substrate using this adhesive sheet, and a method for manufacturing a wiring board using this adhesive sheet. The purpose is to provide.

0010

[Means for Solving the Problems] After extensive research, the present inventors have discovered that the cause of unevenness on the surface of an insulating substrate on which an adhesive layer is formed is: Since reinforcing fibers such as glass cloth are used, the unevenness of the fibers becomes the unevenness of the substrate surface itself. % or less, and when the solvent is heated and evaporated, the volume decreases significantly, causing unevenness on the surface depending on the solid content distribution, and air bubbles remain in the adhesive during volatilization, causing unevenness. ■ As mentioned above, conventional adhesives have a small solid content by weight and tend to remain inside even after the insulating substrate coated with the adhesive has been manufactured, and the remaining solvent can affect heat resistance and electrolytic corrosion resistance - It was found that insulation properties such as moisture absorption insulation deteriorate.

Based on these analysis results, we have found that by using a specific ultraviolet curable adhesive, we can fill in the irregularities formed on the insulating substrate and make the surface smooth, and we can also use a specific ultraviolet-curable adhesive to make the surface smooth. The knowledge that it is possible to use an adhesive was obtained, and the present invention was made based on this knowledge.

As shown in FIG. 1(a), the ultraviolet curable adhesive sheet of the present invention comprises a viscous liquid adhesive composition layer 100 containing a resin that can be cured by ultraviolet rays, and the adhesive composition layer 100. It is characterized by comprising a release film 2 that does not adhere to the layer 100 when the resin is cured.

The release film 2 may be formed on both sides of the adhesive as shown in FIG. 1(b).

Further, it is preferable to include an electroless plating catalyst in the resin of the adhesive composition layer 100, as shown in FIG. 1(c), since the step of applying the plating catalyst can be omitted. As such a catalyst for electroless plating, one or more catalysts selected from palladium, silver, platinum, gold, or chlorides thereof can be used.

[0015] As the resin that can be cured by ultraviolet light, a resin selected from the group consisting of phenol, epoxy, melamine, acrylic, acrylate, polyester, polyvinyl butyral, and mixtures thereof is used. It may also be cured by heating in combination with ultraviolet irradiation. As the curing agent, radical polymerization type acetophenone type, benzoin type, benzophenoin type, and thioxanthone type can be used, and cationic polymerization type can also be used. Examples of the acetophene-based curing agent include 4-phenoxydichloroacetofeine, 4-t-butyltrichloroacetofeine,
Examples of benzoin-based curing agents include benzoin, benzoin methyl ether, and benzoin ethyl ether. Examples of benzophane-based curing agents include benzophane and O-benzoylbenzoic acid. Examples of thioxanthone-based curing agents include 2-chlorothioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, and cationic hardeners such as methyl and chlorobenzophene.
P-methoxybenzenediazonium hexalolophosphate, diphenyl iodonium hexalolophosphate, etc. can be used.

[0016] An adhesive sheet that can be cured by ultraviolet irradiation or ultraviolet light and heating has a viscosity of 1 in the semi-cured state.
It is preferable that it is in the range of 5,000 to 40,000 poise at 00°C. When the viscosity is less than 5000 poise, the flow of the resin becomes large and the resin deforms during storage. If it is 40,000 poise or more, the flow is too small to fill in the unevenness on the surface of the insulating substrate, and the adhesion to the substrate deteriorates.

[0017] As a method for producing such an adhesive sheet, a viscous liquid composition containing a resin that can be cured by ultraviolet rays is mixed with a release film that does not adhere to the resin while the resin is semi-cured. This can be done by coating the surface, reducing the pressure during or after coating, and semi-curing by irradiating ultraviolet rays or irradiating ultraviolet rays and heating.

The release film used at this time is as follows:
Fluororesin film, vinyl fluoride resin film, polypropylene film, methylpentene resin film, polyethylene film, polyester film coated with a release agent, copper foil, aluminum foil, etc. can be used.

When coating a viscous liquid composition containing this resin or when reducing the pressure after coating, if the pressure is reduced to 60 mmHg or less, the volume ratio of the remaining bubbles will be 5% or less, which is preferable. If there is, no bubbles will remain, which is more preferable.

In order to manufacture such an ultraviolet curable adhesive sheet, as shown in FIG. an adhesive tank 7 that supplies a viscous liquid adhesive composition; and a release film 2 that receives the adhesive composition from the adhesive tank 7 and does not adhere to the resin when the resin is cured. a coater roll 6 for coating the adhesive composition on the resin, a guide roller 8 for sandwiching and guiding the release film 2 in pair with the coater roll 6, and an ultraviolet lamp 16 for irradiating ultraviolet light to cure the resin. and a pressure reduction layer 1 for reducing the pressure after coating the adhesive composition, and the pressure reduction layer 1 includes a sealing element 3 that contacts each of the coater roll 6 and the guide roller 8, and a pressure reduction layer 1 for reducing the pressure after coating the adhesive composition. A device for winding up the release film 2 as an adhesive sheet 10, comprising a sealer 3 provided at an outlet for transporting the released release film 2 out of the reduced pressure layer 1, and the ultraviolet lamp 16 inside the reduced pressure layer 1. Use.

Moreover, the depressurization is not performed after coating, but as shown in FIG. This is preferable because it can also remove air bubbles in the adhesive.

[0022] Further, using such an ultraviolet curable adhesive sheet, the release film of the ultraviolet curable adhesive sheet is peeled off, and it is laminated by stacking it on an insulating resin plate that has already been cured or semi-cured. By,
As shown in FIG. 1(d), a substrate for an additive wiring board can be manufactured. It is preferable to reduce the pressure during this lamination because it can remove air bubbles remaining in the irregularities on the surface of the insulating resin plate.

[0023] Furthermore, such an insulating resin plate can also contain a catalyst for electroless plating, which is preferable since it is possible to omit the step of applying a plating catalyst when forming through-holes. As such a catalyst for electroless plating, catalysts similar to those that can be included in the above-mentioned adhesive can be used. As the resin that can be used for the insulating resin board, resins selected from the group consisting of phenolic resin, epoxy resin, polyimide resin, polyester resin, fluororesin resin, and mixtures thereof can be used. Woven or nonwoven fabrics made of inorganic fibers or organic fibers such as nylon fibers, polyester fibers, and polyimide fibers can also be impregnated, which is preferred because the mechanical strength can be increased. As a curing agent for such a resin, any ordinary thermosetting type can be used.

[0024] When the ultraviolet curable adhesive sheet is laminated on the insulating resin plate under reduced pressure, it is preferable to reduce the pressure to 60 mmHg or less to eliminate air bubbles during lamination.

[0025] The pressure during this stacking is 5 kgf.
It is preferable to use a pressure of /cm or more because it can improve the smoothness of the surface when used as a base material. In order to perform such high-pressure lamination, the pressure adjustment cam of the film laminator shown in Figures 5 and 6 must be set to the maximum level, although the pressure is not used in ordinary resist film laminating equipment. Either the pressure can be adjusted so that the pressure is increased, or the pressure can be increased by replacing the pressure adjusting cam with a hydraulic device as shown in FIG. Furthermore, adhesion can be improved by heating the resin plate during lamination.

As an apparatus for manufacturing such a wiring board substrate, as shown in FIG. 5, the adhesive sheet manufactured by the apparatus shown in FIGS. The cured insulating resin plate is sent into the vacuum container 11, the adhesive sheet 10 is laminated with the laminating roll 14, and the board is transported to B. At this time, the laminating pressure can be increased by the pressure cam 18. For such devices, there is a
The laminator disclosed in Japanese Patent No. 3-31670 can be used. If such a laminator is used to supply the adhesive sheet 10 from the outside of the vacuum container 11 as shown in FIG. 6, as shown in FIG. It can be used continuously, and a wiring board substrate can be manufactured efficiently.

Furthermore, the insulating resin plate is supplied with reinforcing fibers.
If it is connected to a device that continuously manufactures resin impregnation, resin squeezing, and curing in this order, it is possible to create a series of continuous manufacturing devices from reinforcing fibers, which is preferable because efficiency can be greatly improved.

[0028] Also, using a wiring board substrate using such an adhesive sheet, holes are made at desired locations to serve as through holes for connecting circuit conductors on the front and back sides, and electroless plating is used to completely seal the holes. A wiring board can be manufactured by forming a metal layer at necessary locations on the surface of a cured ultraviolet curable adhesive sheet and on the inner walls of holes that will become through holes. (Hereafter, margin)

[0029]

[Operation] Since an ultraviolet curing resin is used for the adhesive sheet, a sheet with high dimensional stability can be created without the need for heating, and since the coating is applied under reduced pressure, air bubbles can be prevented from being entrained. Furthermore, since an ultraviolet curable adhesive is used, the solid content can be increased, the amount of solvent remaining in the adhesive can be suppressed, and the generation of bubbles due to volatilization of the solvent can be suppressed. Air bubbles can be further suppressed by reducing the pressure when manufacturing wiring board substrates. When manufacturing wiring board substrates, lamination is performed under higher pressure than normal laminates, making it easier to obtain surface smoothness and making it possible to form finer circuits.

[0030]

EXAMPLES (1) Preparation of adhesive sheets Adhesive sheets 1 to 6 having the respective compositions were prepared using the apparatus shown in FIG. 3 using resins and curing agents having the following compositions. At this time, coating was performed under reduced pressure of 50 mmHg. The ultraviolet rays were irradiated at 100 mJ/cm2, and the viscosity was 30,000 poise at a temperature of 100°C. The thickness of the adhesive sheet was 30 μm, and the release film used was a release-treated polyester film having a thickness of 35 μm.

{Adhesive sheet 1} Alkylphenol resin H2400 (trade name manufactured by Hitachi Chemical Co., Ltd.) 45 parts by weight Epoxy resin E828 (trade name manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts by weight Aluminum hydroxide Higilite H-24M (trade name manufactured by Showa Light Metal Co., Ltd.) 15 parts by weight Methyl ethyl ketone
10 parts by weight
Photoinitiator SP-170 (trade name manufactured by Asahi Denka Kogyo Co., Ltd.) 0.2 parts by weight

0032
] {Adhesive sheet 2} Epoxy resin E828 (trade name manufactured by Yuka Shell Epoxy Co., Ltd.) 60 parts by weight Epoxy resin E1001 (trade name manufactured by Yuka Shell Epoxy Co., Ltd.) 10 parts by weight Polyvinyl
Rubutilal S-LEC BM2 (trade name manufactured by Sekisui Chemical Co., Ltd.) 5 parts by weight Calcium carbonate
1
5 parts by weight Photoinitiator UVI-6970 (trade name manufactured by Union Carbide) 0.8 parts by weight Methyl ethyl ketone
10 parts by weight

{Adhesive sheet 3} Polyvinyl butyral S-LEC BM-2 (trade name manufactured by Sekisui Chemical Co., Ltd.) 10 parts by weight Phenol
Melamine resin H-2400 (trade name manufactured by Hitachi Chemical Co., Ltd.) 5 parts by weight Melamine resin Melan 523 (trade name manufactured by Hitachi Chemical Co., Ltd.) 5 parts by weight Epoxy resin E828 (trade name manufactured by Yuka Shell Epoxy Co., Ltd.) 35 Part by weight Calcium carbonate
1
5 parts by weight methyl ethyl ketone
30 parts by weight Photoinitiator SP-170 (trade name manufactured by Asahi Denka Kogyo Co., Ltd.) 0.4 parts by weight

0034
] {Adhesive sheet 4} 2-hydrikiethyl methacrylate
20 parts by weight EO modified bisphenol A dimethacrylate
30 parts by weight Epoxy resin E828 (trade name manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts by weight Calcium carbonate
2
0 parts by weight Photoinitiator Benzophenone

0.7 parts by weight Imidazole 2PZ-CNS (trade name manufactured by Shikoku Kasei Kogyo Co., Ltd.) 1.4 parts by weight

0035 {
Adhesive sheet 5} Polyester resin Vylon 400 (trade name manufactured by Toyobo Co., Ltd.) 15 parts by weight Phenol resin H2400 (trade name manufactured by Hitachi Chemical Co., Ltd.) 25 parts by weight Epoxy resin E828 (Yuka Shell Epoxy Co., Ltd.) Company product name) 30 parts by weight Aluminum hydroxide Hygilite H-42M (Product name by Showa Light Metal Co., Ltd.) 15 parts by weight Methyl ethyl ketone
15 parts by weight Photoinitiator UVI-6970 (trade name manufactured by Union Carbide) 0.4 parts by weight

{Adhesive sheet 6} Methylated melamine resin Melan 523 (trade name manufactured by Hitachi Chemical Co., Ltd.) 10 parts by weight Phenoxy resin YP-50 (trade name manufactured by Toto Kasei Co., Ltd.)
20 parts by weight
Epoxy resin E828 (trade name manufactured by Yuka Shell Epoxy Co., Ltd.) 40 parts by weight Calcium carbonate
1
0 parts by weight methyl ethyl ketone

20 parts by weight Photoinitiator SP-170 (trade name manufactured by Asahi Denka Kogyo Co., Ltd.) 0.4 parts by weight

0037
{Comparative Adhesive Sheet 1} An adhesive sheet having the same composition as Adhesive Sheet 1 was used, but an adhesive sheet was prepared using the apparatus shown in FIG. 3 without using the pressure reducing device.

{Comparative Adhesive Sheet 2} An adhesive sheet was prepared using a thermosetting resin and curing agent.

(2) Preparation of test sample A test sample was prepared from the adhesive prepared as described above in the following manner. Glass cloth epoxy resin insulation board LE-
67N (trade name manufactured by Hitachi Chemical Co., Ltd.), paper epoxy resin insulation board LP-147F (trade name manufactured by Hitachi Chemical Co., Ltd.), glass cloth polyimide resin insulation board LI-67N (
Example 1 for each of Hitachi Chemical Co., Ltd. (product name)
The adhesive sheets prepared in ~6 and Comparative Examples 1 and 2 were
kgf/cm, heat and pressurize at 175° C. for 80 minutes to integrate the lamination, and remove the release film.

Examples 1 to 6 are samples in which a glass cloth epoxy resin insulating board and adhesive sheets 1 to 6 are combined, and samples in which a paper epoxy resin insulating board and adhesive sheets 1 to 6 are combined are referred to as Examples 1 to 6. Examples 7 to 12 are samples, Examples 13 to 18 are samples in which a glass cloth polyimide resin insulating plate and adhesive sheets 1 to 6 are combined, and a glass cloth epoxy resin insulating plate and a comparative adhesive sheet are used. Comparative Examples 1 and 2 are samples in which 1 or 2 are combined, Comparative Examples 3 and 4 are samples in which paper epoxy resin insulation board and comparative adhesive sheet 1 or 2 are combined, and glass cloth polyimide resin insulation Comparative Example 5 or 6 is a sample in which the board and Comparative Adhesive Sheet 1 or 2 are combined.

Next, a hole with a diameter of 1 mm was drilled, and the surface was polished using a belt-type polisher using No. 800 abrasive material.

Next, it is immersed in a chemical roughening solution (mixed acid of sulfuric acid and chromic acid) at 50°C for 5 to 15 minutes, washed with water, and further immersed in a neutralizing solution with a pH of approximately 4 containing 30 g/liter of NaHSO4 for 20 minutes. and washed with water.

Next, in order to impart a catalyst, it was immersed in HS-101B (trade name, manufactured by Hitachi Chemical Co., Ltd.), which is an aqueous solution containing palladium at room temperature, for 10 minutes, and washed with water.
It was dried at 90°C for 45 minutes.

Next, a photoresist, Photoc SR-3000 (trade name, manufactured by Hitachi Chemical Co., Ltd.), was applied.
Roll lamination was carried out under the conditions of a roll temperature of 100°C, a pressure of 2 kg/cm, and a substrate feed rate of 0.5 m/min, and the test pattern shown in Fig. 2 was baked and developed on the areas where electroless plating would not be deposited. It was formed by Next, electroless plating solution L-5
Plated copper having a thickness of about 25 μm was deposited using a plating solution No. 9 (trade name, manufactured by Hitachi Chemical Co., Ltd.) to form a test pattern. As a result of examining pattern accuracy, heat resistance, electrolytic corrosion resistance, and moisture absorption insulation properties, as shown in Tables 1, 2, and 3, it was possible to obtain higher characteristics than the comparative example. The pattern accuracy, heat resistance, electrolytic corrosion resistance, and moisture absorption insulation properties were investigated as follows.

(3) Investigation method (pattern accuracy) Using pattern A among the patterns shown in FIG. 2, the degree to which the pattern had been formed was visually investigated using a microscope. This pattern has a thickness of 20 μm to 120 μm on each conductor 11.
The width was changed every 10 μm up to μm, and 5 conductors were formed at a time, and the pitch between the conductors was kept constant at 0.3 mm. As a result, the width of the narrowest pattern among the patterns that could be formed was recorded.

(Heat resistance) Using pattern B of the patterns shown in FIG. 2, an investigation was conducted using the test method according to the MIL-P-55110 standard. The investigation conditions were as follows: 1.
After floating for 0 seconds, the sample was cut, and its cross section was observed with an optical microscope at 200x magnification to check for blisters, peeling, and voids. Please note that the results will not swell, peel, or
If there is at least one void in each case, it is marked as ×, if there is any one of them, it is marked as Δ, and if there is no void at all, it is marked as 0.

(Electrolytic corrosion resistance) Of the patterns shown in FIG.
under the conditions of 85°C and 85% relative humidity.
A DC voltage of 100 V was applied between adjacent conductors for 0 hours, and migration occurring between the conductors was observed using an optical microscope at a magnification of 200 times. As a result of observation, when conductors are short-circuited due to migration, ×
, Δ if there is a short circuit but not, and ○ if there is no short circuit.

(Moisture absorption insulation) Using pattern D of the patterns shown in FIG. 2, a pressure cooker test (125°C,
2 atm) for 30 minutes, and insulation resistance was measured under conditions of 500 V DC for 1 minute.

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

[Table 3]

[0052]

[Effects of the Invention] As explained above, the present invention can be used for higher-density wiring than the conventional additive method wiring board, and has heat resistance, electrolytic corrosion resistance, and hygroscopic insulation properties that are almost equivalent to or better than the conventional wiring boards. The above adhesive sheet, a method and apparatus for manufacturing the adhesive sheet, and a method for manufacturing a circuit board substrate using such an adhesive sheet could be provided.

[Brief explanation of the drawing]

FIG. 1 (a) to (f) are cross-sectional views showing respective embodiments of the present invention.

FIG. 2 is a top view of a pattern for investigating the characteristics of an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing an outline of an apparatus for manufacturing an adhesive sheet according to an embodiment of the present invention.

FIG. 4 is a sectional view schematically showing another apparatus for manufacturing an adhesive sheet according to an embodiment of the present invention.

FIG. 5 is a sectional view showing an outline of an apparatus for manufacturing a wiring board substrate using an adhesive sheet according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view schematically showing another apparatus for manufacturing a wiring board substrate using an adhesive sheet according to an embodiment of the present invention.

FIG. 7 is a cross-sectional view showing an outline of another apparatus for manufacturing a wiring board substrate using an adhesive sheet according to an embodiment of the present invention.

FIG. 8 is a cross-sectional view schematically showing an apparatus in which an apparatus for manufacturing an adhesive sheet according to an embodiment of the present invention and an apparatus for manufacturing a circuit board substrate using the adhesive sheet are connected. .

9A to 9F are cross-sectional views for explaining the manufacturing process of a wiring board by the additive method of the first conventional example.

FIGS. 10(a) to 10(f) are cross-sectional views for explaining the manufacturing process of a wiring board by the additive method of a second conventional example.

FIGS. 11A to 11D are cross-sectional views for explaining the manufacturing process of a wiring board by an additive method according to a third conventional example.

12A to 12D are cross-sectional views for explaining the manufacturing process of a wiring board by another additive method of the third conventional example.

[Explanation of symbols]

1. Decompression tank 2. Release film 3.
Roller 4. Adhesive composition 5. Coater roller6. Insulating board 7. Adhesive composition supply tank8. Guide roller 9. Catalyst 10 for electroless plating
．． adhesive sheet

Claims (17)

[Claims] 1. An ultraviolet curable adhesive sheet comprising a viscous liquid adhesive composition containing a resin that is cured by ultraviolet rays, and a release film that does not adhere to the resin when the resin is cured. 2. The ultraviolet curable adhesive sheet according to claim 1, wherein the resin contains an electroless plating catalyst. 3. The ultraviolet curing type according to claim 2, wherein the electroless plating catalyst is one or more selected from palladium, silver, platinum, gold, or a chloride thereof. adhesive sheet. 4. The resin is selected from the group consisting of phenolic, epoxy, melamine, acrylic, acrylate, polyester, polyvinyl butyral, and mixtures thereof. The ultraviolet curable adhesive sheet according to any one of claims 1 to 3. 5. The resin that is cured by ultraviolet rays comprises:
The ultraviolet curable adhesive sheet according to any one of claims 1 to 4, characterized in that it can be cured also by heating. 6. The adhesive composition containing ultraviolet rays or a resin that is cured by ultraviolet rays and heating has a viscosity in the range of 5,000 to 40,000 poise at 100° C. in a semi-cured state. 5. The ultraviolet curable adhesive sheet according to any one of 5. 7. The viscous liquid adhesive composition containing ultraviolet rays or a resin that can be cured by ultraviolet rays and heating has a solid content of 70% or more by weight. 6. The ultraviolet curable adhesive sheet according to any one of . 8. A step of coating a viscous liquid adhesive composition containing a resin that can be cured by ultraviolet light on the surface of a release film that does not adhere to the resin when the resin is cured; A method for producing an ultraviolet curable adhesive sheet, comprising a step of semi-curing by irradiation or ultraviolet irradiation and heating, and reducing the pressure during or after coating. 9. The ultraviolet curable adhesive according to claim 8, wherein the pressure is reduced to 60 mmHg or less when coating the viscous liquid composition containing the resin or when reducing the pressure after coating. Seat manufacturing method. 10. A supply roll 5 that supplies a release film 2, an adhesive tank 7 that supplies a viscous liquid adhesive composition containing ultraviolet rays or a resin that can be cured by ultraviolet rays and heat, and the adhesive. A coater roll 6 that receives the adhesive composition from the tank 7 and coats the release film 2 that does not adhere to the resin when the resin is cured with the adhesive composition; A guide roller 8 that pinches and guides the release film 2
, an ultraviolet lamp 16 that irradiates ultraviolet rays for curing the resin, and a pressure reduction layer 1 for reducing the pressure after coating the adhesive composition, and the pressure reduction layer 1 includes the coater roll 6 and the guide. A sealing element 3 that contacts each of the rollers 8, a sealing element 3 provided at an outlet for transporting the coated release film 2 out of the vacuum layer 1, and a sealing element 3 that contacts each of the rollers 8; An apparatus for manufacturing an ultraviolet curable adhesive sheet, comprising a lamp 16. 11. A supply roll 5 that supplies a release film 2, an adhesive tank 7 that supplies a viscous liquid adhesive composition containing ultraviolet rays or a resin that can be cured by ultraviolet rays and heat, and the adhesive. A coater roll 6 that receives the adhesive composition from the tank 7 and coats the release film 2 that does not adhere to the resin when the resin is cured with the adhesive composition; A guide roller 8 that pinches and guides the release film 2
, an ultraviolet lamp 16 that irradiates ultraviolet rays to cure the resin, and a pressure reduction layer 1 for reducing pressure when coating the adhesive composition, and the pressure reduction layer 1 includes:
A sealing element 3 that contacts the release film 2 before being coated, a sealing element 3 provided at an outlet for transporting the coated release film 2 out of the reduced pressure layer 1, and a reduced pressure thereof. An apparatus for producing an ultraviolet curable adhesive sheet, characterized in that the layer 1 includes the coater roll 6, the guide roller 8, the adhesive tank 7, and the ultraviolet lamp 16. 12. A heat source 17 is further provided in the decompression tank 1.
The apparatus for producing an ultraviolet curable adhesive sheet according to claim 10 or 11, characterized by comprising: 13. A method for manufacturing a wiring board substrate, the method comprising the following steps. A. A process of coating a viscous liquid adhesive composition containing a resin that can be cured by ultraviolet rays on the surface of a release film that does not adhere to the resin when the resin is cured, and irradiation with ultraviolet rays or irradiation with ultraviolet rays. and a step of semi-curing by heating, and a step of reducing the pressure at the time of coating or after coating B. C. Peeling off the release film of the semi-cured ultraviolet curable adhesive sheet and laminating it on the already cured or semi-cured insulating material using a roll under reduced pressure. Following the lamination in step B above, a step of completely curing by irradiation with ultraviolet rays. 14. Claim 13, wherein when the ultraviolet curable adhesive sheet is laminated on the resin plate under reduced pressure, the lamination is performed under a pressure of 5 kgf/cm or more.
A method for manufacturing a wiring board substrate described in . 15. The already hardened or semi-hardened insulating material is impregnated into a woven or nonwoven fabric made of inorganic fibers such as glass fibers or organic fibers such as nylon fibers, polyester fibers, polyimide fibers, etc. 15. The method for manufacturing a wiring board substrate according to claim 13 or 14. 16. The method for manufacturing a wiring board substrate according to claim 13, wherein the already cured or semi-cured insulating material is a flexible insulating film. 17. A method for manufacturing a wiring board, comprising the following steps. A. A process of coating a viscous liquid adhesive composition containing a resin that can be cured by ultraviolet rays on the surface of a release film that does not adhere to the resin when the resin is cured, and irradiation with ultraviolet rays or irradiation with ultraviolet rays. and a step of semi-curing by heating, and a step of reducing the pressure at the time of coating or after coating B. C. Peeling off the release film of the semi-cured ultraviolet curable adhesive sheet and laminating it on the already cured or semi-cured insulating material using a roll under reduced pressure. Following the lamination in step B, there is a step D. in which the lamination is completely cured by irradiation with ultraviolet rays. Following the above step C, step E of drilling holes to serve as through holes for connecting the circuit conductors on the front and back sides at desired locations.
．． A step of forming a metal layer by electroless plating at necessary locations on the surface of the ultraviolet curable adhesive sheet completely cured in step C and on the inner walls of the holes provided in step D.