JP3861537B2 - Vacuum lamination method of adhesive film - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method for vacuum-laminating a film adhesive on an inner layer circuit pattern in a method for manufacturing a multilayer printed wiring board of a build-up system in which conductor circuit layers and insulating layers are alternately stacked.
[0002]
[Prior art]
2. Description of the Related Art In recent years, attention has been paid to a build-up type multilayer printed wiring board manufacturing technique in which organic insulating layers are alternately stacked on a conductor layer of an inner circuit board. In JP-A-8-64960, an undercoat adhesive is applied, and after temporary drying, a film-like additive adhesive is bonded and heat-cured, roughened with an alkaline oxidizing agent, and a conductor layer is formed by plating to produce a multilayer printed wiring board. How to do is known. In addition, in the Japanese Patent Application No. Hei 9-357420, the present inventors can simultaneously coat the inner layer circuit pattern and fill the resin in the surface via hole and / or through hole at the same time, and an interlayer adhesive film for a multilayer printed wiring board, and The manufacturing method of the multilayer printed wiring board using this is disclosed. When this adhesive film is laminated with heat-resistant rubber under vacuum under heat and pressure conditions, it is excellent in embedding of the adhesive into the inner layer circuit and has the advantage of excellent productivity because it does not require an undercoating process. Due to the characteristic of following the inner layer circuit, the adhesive has irregularities along the circuit pattern and the surface smoothness is deteriorated, which causes a problem in the subsequent component mounting process.
[0003]
[Problems to be solved by the invention]
In view of the above problems, the present inventors have formed an adhesive film comprising a support base film and a heat-flowable, room-temperature solid resin composition layer laminated on the surface of the support base film and the surface thereof, as an inner layer circuit of a circuit board. In the method of vacuum laminating on a pattern, the object is to develop a vacuum laminating method excellent in surface smoothness of the contact surface of the film-like adhesive layer which is the resin composition layer with the support base film.
[0004]
[Means for Solving the Problems]
The present invention provides a heating and pressurizing condition on a patterned circuit board of an adhesive film comprising a support base film and a heat-flowable, room-temperature solid resin composition layer laminated on the surface thereof. In the manufacturing method of the multilayer printed wiring board that is vacuum laminated under,
1) via the resistance heat rubber, heat and pressure than the supporting base film side, higher engineering you vacuum laminating an adhesive film and 2) said vacuum subsequently emptied stack to process, press the metal from the supporting base film side heating and pressurizing have use a plate, to perform a more Engineering you smooth the resin composition layer surface in contact with the supporting base film, in the step of further smoothing the resin composition layer surface, to the support base film after the surface smoothness of the larger area than the adhesive film that the placing of the protective film, the resin composition surface in contact with the heating and pressing the support base film using a pressing metal plate from the top of the protective film smoothness A method for producing a multilayer printed wiring board .
[0005]
DETAILED DESCRIPTION OF THE INVENTION
The adhesive film used in the present invention is a resin composition which is a heat fluidity, solid at room temperature by applying a resin varnish dissolved in a predetermined organic solvent using a support base film as a support and then drying the solvent by heating and / or hot air blowing. The layer can be prepared by a known and conventional method. The adhesive film is stored as it is or by further laminating a release film on the other surface of the resin composition, and wound into a roll.
[0006]
The heat fluidity and room temperature solid resin composition includes a thermosetting resin and / or a polymer as a main component, and is a resin composition that is softened by heating and has a film-forming ability, and further heat-cured. There is no particular limitation as long as it satisfies the characteristics required for the interlayer insulating material such as heat resistance and electrical characteristics. For example, an epoxy resin system, an acrylic resin system, a polyimide resin system, a polyamideimide resin system, a polycyanate resin system, a polyester resin system, a thermosetting polyphenylene ether resin system, and the like can be used. An adhesive film layer having a multilayer structure can also be used. Among these, an epoxy resin composition described in Japanese Patent Application No. 9-357420 is preferable in an epoxy resin system having excellent reliability and cost as an interlayer insulating material.
[0007]
The resin composition layer is formed by laminating a resin composition of heat fluidity and room temperature solid on the support base film. The thickness of the resin composition layer is equal to or greater than the conductor thickness of the laminated inner circuit board, and the conductor thickness + (10 to 120) μm. Generally, it is in the range.
[0008]
Examples of the supporting base film include polyolefins such as polyethylene and polyvinyl chloride, polyesters such as polyethylene terephthalate, polycarbonate, and metal foils such as release paper, copper foil, and aluminum foil. The thickness of the support base film is generally 10 to 150 μm. The support film may be subjected to a mold release treatment in addition to the mud treatment and the corona treatment.
[0009]
A vacuum applicator manufactured by Nichigo-Morton Co., Ltd. is used to heat and press the heat-resistant rubber from the support base film side of the adhesive film and vacuum laminate the resin composition layer of the adhesive film on the circuit board. Commercially available vacuum laminating machines such as a vacuum pressurizing laminator manufactured by Meiko Seisakusho and a vacuum laminator manufactured by Taisei Laminator Co., Ltd. can be used. These machines generally have a structure in which heat-resistant rubber is sandwiched between them. When laminating, a circuit board in which the adhesive film is preliminarily sheeted with the same area size as the circuit board is put in, and the heat fluidity, room temperature solid resin composition layer is heated and pressed from the support base film side to laminate. Alternatively, in a state where the roll-shaped adhesive film is set on the base roll of a vacuum laminator, the heat fluidity, room temperature solid resin composition layer is heated and pressed from the support base film side, and then cut to a predetermined size. By laminating under the condition that the resin flow during laminating is equal to or greater than the conductor thickness of the inner layer circuit, the inner layer circuit pattern is covered well, but the heat resistant rubber is flexible and follows the uneven shape of the conductor of the inner layer circuit. Although the heat fluidity and room temperature solid resin composition layer and the circuit board are in close contact with each other, the surface smoothness of the contact surface of the resin composition layer with the support base film is impaired.
[0010]
In order to solve this problem, the circuit board on which the adhesive film is vacuum-laminated is sandwiched between a protective film having a larger area than the adhesive film and a metal plate for pressing and / or a metal roll for laminating. Heat and press at to smooth the adhesive film. As the machine, a commercially available laminating machine such as a hot plate press or a heating and pressurizing laminator can be used. FIG. 1 shows a simple schematic diagram with a metal plate, and FIG. 2 shows a simple schematic diagram with a metal roll. At the time of smoothing, the circuit board on which the adhesive film is vacuum-laminated is heated and pressurized with a room-temperature solid resin composition from the protective film and support base film side. By pressing and / or laminating under the heating and pressurizing conditions equivalent to or higher than the conditions in vacuum lamination, the contact surface of the resin composition layer with the support base film can be smoothed.
[0011]
Examples of the protective film include polyolefin such as polyethylene and polypropylene, polyester such as polyethylene terephthalate, polycarbonate, and metal foil such as release paper and aluminum foil. The protective film is used for the purpose of preventing the metal plate and / or the metal roll from being damaged by a foreign substance or preventing the stain due to the stain of the adhesive, and the surface is smooth and the thickness is preferably in the range of 5 to 100 μm. .
[0012]
The vacuum lamination method of the adhesive film of the present invention is
1) Heat and pressure are applied from the support base film side through a heat-resistant rubber having a larger area than the pattern part of the circuit board, and the adhesive film is vacuum laminated in the order of support base film / the resin composition layer / pattern part of the circuit board. The first step and 2) placing the pressing metal plate or laminating metal roll on the support base film of the circuit board on which the adhesive film is vacuum-laminated, and heating and pressurizing to smooth the adhesive film. There is a process, and it is possible to proceed to the second process while keeping the vacuum state in the first process. Further, the circuit board on which the adhesive film is vacuum-laminated may be taken out into the atmosphere once between the first step and the second step. In such a case, the second step can be performed again in a vacuum state, or can be performed in an atmospheric state without being in a vacuum state. In these cases, a supporting base film or / and a protective film having a mud treatment and / or embossing is effective. When at least one of the contact surfaces of the support base film and the protective film is mud-treated and / or embossed, air is easily removed between the protective film and the support base film, and the productivity of the smoothing process is improved. . Also, a plurality of protective films can be used in a stacked manner.
[0013]
The method of vacuum laminating the adhesive film used in the present invention on the patterned circuit board is not limited to the case where the adhesive film is used as an interlayer adhesive film for build-up. Needless to say, the present invention can also be applied to a dry film such as a resist.
[0014]
【Example】
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.
[0015]
[Example of adhesive film production]
20 parts of liquid bisphenol A type epoxy resin (Epicoat 828EL manufactured by Yuka Shell Epoxy Co., Ltd.), 20 parts of brominated bisphenol A type epoxy resin (YDB-500 manufactured by Toto Kasei Co., Ltd.), cresol novolac type epoxy resin (epoxy equivalent) 215, softening point 78 ° C., Dainippon Ink Chemical Co., Ltd. Epiklon N-673) 20 parts, terminal epoxidized polybutadiene rubber (Nagase Kasei Kogyo Co., Ltd. Denarex R-45EPT) 15 parts while stirring in MEK Heat-dissolved, brominated phenoxy resin varnish (non-volatile content 40% by weight, bromine content 25% by weight, solvent composition, xylene: methoxypropanol: methyl ethyl ketone = 5: 2: 8, YPB-40 manufactured by Toto Kasei Co., Ltd. -PXM40) 50 parts, 2,4-diamino-6- ( -Methyl-1 over imidazolylethyl) over 1,3,5 chromatography triazine isocyanuric acid adduct 4 parts finely divided silica, 2 parts of antimony trioxide 4 parts, to produce the added resin composition varnish and 5 parts of calcium carbonate. The varnish was coated on a 25 μm thick polyethylene terephthalate film with a die coater so that the resin thickness after drying was 70 μm, dried at 80 to 120 ° C., and then slit to a width of 507 mm to obtain a roll-shaped adhesive film. It was.
[0016]
[Comparative Example 1]
On the patterned glass epoxy inner layer circuit board of 510x340mm (conductor thickness 35μm), roll-like adhesive film obtained in the production example is used on both sides of the board with the size of 507x336mm in width using the auto cut laminator made by Somaru It was a sheet. The conditions were as follows: the temperature at the temporary attachment part was 70 ° C. and the pressure was applied for 5 seconds, and the laminate roll was at room temperature and no load. Next, both sides were laminated simultaneously with a vacuum applicator 725 manufactured by Morton International Inc. at a temperature of 80 ° C. for 6 seconds. After cooling to near room temperature, the polyethylene terephthalate film was peeled off, and the adhesive surface on the line / space = 320/320 μm was measured with a surface roughness measuring instrument manufactured by Tokyo Seimitsu Co., Ltd., and the maximum height was 8 μm. It was.
[0017]
[Comparative Example 2]
The roll-shaped adhesive film obtained in the production example was set on both base rolls of a vacuum laminator manufactured by Taisei Laminator Co., Ltd., and a patterned 510 × 340 mm glass epoxy inner layer circuit board (conductor thickness 35 μm) was introduced horizontally. The two surfaces were laminated simultaneously at a temperature of 120 ° C., a pressure of 3 kg / cm, and 30 cm / min. After cutting the adhesive film, the polyethylene terephthalate film was peeled off, and when the surface of the adhesive on line / space = 320/320 μm was measured with a surface roughness measuring instrument, the maximum height was 6 μm.
[0018]
[Example 1]
Just as in Comparative Example 1, an adhesive film was laminated on a patterned 510 × 340 mm glass epoxy inner layer circuit board (conductor thickness 35 μm). After that, with a hot-plate press, a double-sided mud-treated polypropylene film (maximum height of 3.5 μm) with a width of 600 mm and a thickness of 15 μm is set as a protective film on both metal surfaces. The substrate was put in and pressed at a temperature of 90 ° C. and a pressure of 5 kg / cm 2 for 20 seconds. After cooling to near room temperature, the polyethylene terephthalate film was peeled off, and when the surface of the adhesive on line / space = 320/320 μm was measured with a surface roughness meter, the maximum height was less than 2 μm.
[0019]
[Example 2]
Just as in Comparative Example 2, an adhesive film was laminated to a patterned 510 × 340 mm glass epoxy inner layer circuit board (conductor thickness 35 μm). Thereafter, a double-sided mud-treated polyethylene terephthalate film (maximum height of 5 μm) having a width of 600 mm and a thickness of 25 μm is set as a protective film on both base rolls of a chrome-plated metal roll laminator, and the protective film is placed from the vicinity of the center. The substrate was put in and smoothed at a temperature of 135 ° C., a pressure of 3 kg / cm, and 50 cm / min. After cooling to near room temperature, the polyethylene terephthalate film was peeled off, and when the surface of the adhesive on line / space = 320/320 μm was measured with a surface roughness meter, the maximum height was less than 2 μm.
[0020]
From the results of Comparative Examples 1 and 2, when the adhesive film was laminated as usual using a commercially available vacuum laminator, the surface smoothness of the adhesive was limited. As is clear from the results of Examples 1 and 2, the adhesive film having heat fluidity can be laminated in a very smooth state according to the method of the present invention.
[0021]
【The invention's effect】
According to the method of the present invention, an adhesive film having heat fluidity can be easily laminated in a state having very excellent surface smoothness.
[Brief description of the drawings]
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a simple process for smoothing an adhesive film by heating and pressing a protective film larger than the adhesive film between press circuit plates on the circuit board on which the adhesive film is vacuum laminated. A schematic diagram is shown.
[Fig. 2] A simple method of smoothing an adhesive film by heating and pressurizing a protective film larger than the adhesive film between the circuit board on which the adhesive film is vacuum laminated and sandwiched between metal rolls for lamination. A schematic diagram is shown.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Metal plate for press 2 Protective film 3 after mud treatment and / or embossing 3 Inner layer circuit board on which adhesive film is vacuum laminated 4 Metal roll for laminating

Claims (3)

Supporting base film and the thermal fluidity laminated on the surface, the multilayer printed wiring board to heat and pressure conditions vacuum laminating the resin composition layer of the adhesive film comprising the resin composition layer of the solid state at room temperature to circuitry on the board In the manufacturing method of
1) via the resistance heat rubber, heat and pressure than the supporting base film side, Engineering more and 2 you vacuum laminating an adhesive film on the circuit board) and have use the press metal plate from the support base film side heating and pressure method for producing a multilayer printed wiring board and performing as engineering you smooth the resin composition layer surface in contact with the supporting base film. A step of smoothing the resin composition layer, said heating and pressing while sandwiched between the press metal plate surface smooth protective film of greater area than the adhesive film in contact with the supporting base film The method for producing a multilayer printed wiring board according to claim 1, which is a step of smoothing the surface of the resin composition layer. The support base film and of the contact surface between the protective film, at least one surface The process of claim 2 wherein the multi-layer printed wiring board, characterized by being mud treatment and / or embossing.

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