JP2001152108A - Insulating adhesive film multi-layer printed-wiring board using the same and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare an insulating adhesive film having excellent flexibility without lowering the glass transition temperature, a multi-layer printed-wiring board using the same and its manufacturing method. SOLUTION: The multi-layer printed-wiring board is composed of an insulating adhesive film comprising a polyfunctional epoxy resin having three or more functional groups, a difunctional epoxy resin which is liquid at 25 deg.C and, simultaneously, has a viscosity of <=100 P, and an acrylonitrile butadiene rubber, an inner circuit substrate having an inner circuit, an insulating layer on the inner circuit substrate, an outer circuit formed on the surface of the insulating layer, and a via hole connecting the inner circuit with the outer circuit, The method of manufacturing the multi-layer printed-wiring board comprises laminating a printed-wiring board constituted of an insulating adhesive film to form an insulating layer on an inner circuit substrate having an inner circuit to effect adhesion with the insulating layer, making a via hole reaching the inner circuit, forming an outer layer circuit on the surface of the insulating adhesive film, and effecting electrical connection between the outer circuit and the inner circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating adhesive film suitable for an insulating material of a build-up multilayer wiring board, a multilayer printed wiring board using the same, and a method of manufacturing the same.

[0002]

2. Description of the Related Art The integration density of electronic components such as semiconductor chips has become extremely high. Therefore, printed wiring boards on which electronic components such as semiconductor chips are mounted are also required to have wiring intervals and connection hole intervals. Higher densities have been achieved by narrowing.

As a method of increasing the density of the printed wiring board, there is a method in which a conductor circuit is formed on a plurality of substrates in advance, laminated and integrated with a glass cloth prepreg sandwiched therebetween, and joined together to form a multilayer printed wiring board. However, since the glass prepreg is made of glass cloth, it is necessary to reduce the number of glass fibers used for the glass cloth. If so, the amount of resin that can be impregnated will decrease, and insulation will decrease.If the amount of impregnating resin is forcibly increased, the distribution of glass fibers will vary, and the dimensional change rate will vary depending on the location. This has caused a problem that the alignment between the layers becomes difficult, which is important for the multilayer printed wiring board.

Therefore, a resin layer is formed as an insulating layer on an inner circuit board on which an inner layer circuit is formed, using only a resin instead of a glass cloth prepreg, and a via hole reaching the inner layer circuit is opened. Build-up multilayer printed wiring boards for forming an outer layer circuit and electrically connecting the outer layer circuit and the inner layer circuit have been developed and implemented. The insulating layer used for this build-up multilayer printed wiring board is usually formed by coating a resin on a support film, heating and drying to make a semi-cured insulating adhesive film, and laminating or pressing the insulating adhesive film. It is formed by doing. Then, after forming a via hole with a laser beam such as a carbon dioxide gas laser, an outer layer circuit is formed on the surface of the insulating layer, and an electrical connection between the outer layer circuit and the inner layer circuit is performed. An additive system in which a conductor is selectively formed on an outer layer circuit and an inner wall of a via hole by selectively plating the upper layer is often used.

[0005]

In addition to the properties of insulation, heat resistance, and plating peel strength, such an insulating adhesive film has a film forming ability and a film crack when winding or unwinding the film. It is required to have better flexibility than liquid material for prevention. Therefore, usually, the main component is acrylonitrile butadiene rubber capable of achieving both flexibility and plating peel strength, and in order to ensure heat resistance, acrylonitrile butadiene rubber is cross-linked with a phenol resin to ensure insulation. And an epoxy resin and its curing agent, and an inorganic filler for the purpose of reinforcing mechanical strength.

Epoxy resin 10 is used for the insulating adhesive film.
A rubber amount of 25 parts by weight or more is required with respect to 0 parts by weight, and the glass transition temperature of the cured resin is easily lowered, and the glass transition of 150 ° C. or more required for use in the package field for mounting semiconductor chips. It was very difficult to get the temperature.

It is an object of the present invention to provide an insulating adhesive film which is excellent in flexibility without lowering the glass transition temperature, a multilayer printed wiring board using the same, and a method for producing the same.

[0008]

The present invention is characterized by the following. (1) An insulating adhesive film comprising a trifunctional or higher polyfunctional epoxy resin, a bifunctional epoxy resin which is liquid at 25 ° C. and has a viscosity of 100 poise or less, and acrylonitrile butadiene rubber. (2) The insulating adhesive film according to (1), wherein the polyfunctional epoxy resin is 30 to 60% by weight, the bifunctional epoxy resin is 15 to 30% by weight, and the acrylonitrile butadiene rubber is 5 to 12% by weight. (3) an inner circuit board on which an inner circuit is formed, an insulating layer formed thereon, an outer circuit formed on the surface of the insulating layer,
A multilayer printed wiring board comprising via holes connecting an inner layer circuit and an outer layer circuit, wherein the insulating layer is made of the insulating adhesive film according to (1) or (2). (4) The insulating adhesive film according to (1) or (2) is laminated and adhered to the inner circuit board on which the inner circuit is formed, a via hole reaching the inner circuit is opened, and an outer circuit is formed on the surface of the insulating adhesive film. And a method of manufacturing a multilayer printed wiring board for electrically connecting an outer layer circuit and an inner layer circuit.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a polyfunctional epoxy resin, various phenol novolak type epoxy resins, cresol novolak type epoxy resins and the like can be used, and there is no particular limitation. In order to impart flame retardancy to the insulating resin, a brominated product thereof may be used. The compounding amount is preferably 30 to 60% by weight. If the compounding amount of the polyfunctional epoxy resin is less than 30% by weight, the crosslink density of the cured insulating material is greatly reduced, so that the glass transition temperature may be lowered. If it exceeds 60% by weight, the flexibility of the cured insulating material is reduced. This is because there is a risk of doing so.

As the liquid bifunctional epoxy resin, various bisphenol A epoxy resins, bisphenol F epoxy resins, aliphatic epoxy resins and the like can be used, and those having a viscosity of 100 poise or less at 25 ° C. are used. It is necessary. When a liquid bifunctional epoxy resin having a viscosity exceeding 100 poise or a bifunctional epoxy resin solid at room temperature is used, sufficient flexibility cannot be imparted to the film. Under such 25 ° C. conditions, 10
Commercially available liquid bifunctional epoxy resins of 0 poise or less include Epicoat 801, 815, 828, and 834 (all manufactured by Yuka Shell Epoxy Co., Ltd., trade name) KRM
2110, 2410 (both manufactured by Asahi Denka Kogyo Co., Ltd.
Product name). Further, the compounding amount of the above-mentioned liquid bifunctional epoxy resin is preferably 15 to 30% by weight. If the amount is less than 15% by weight, sufficient flexibility may not be obtained in the film, and if it exceeds 30% by weight, the glass transition temperature may be greatly reduced.

Acrylonitrile butadiene rubber of various molecular weights can be used, but in consideration of roughening properties, elastic modulus and compatibility with other resins, the weight average molecular weight (standard by gel permeation chromatography) is used. (Measured using a polystyrene calibration curve) is 500
It is preferable to use one having about 0 to 30,000. Further, the compounding amount is 5 to 12% by weight. If the amount of acrylonitrile-butadiene rubber is less than 5% by weight, sufficient surface irregularities cannot be formed during roughening, and the plating peel strength may be greatly reduced. If it exceeds 12% by weight, the glass transition temperature may be reduced. Because there is.

Phenol novolak, imidazole, polyamines and the like can be used as a curing agent for polyfunctional and liquid bifunctional epoxy resins, and various alkylphenol resins can be used as a crosslinking agent for acrylonitrile butadiene rubber. Although it is possible, it is preferable to use a phenol novolak or an imidazole-based curing agent in order to obtain an insulating cured product having a high glass transition temperature of 150 ° C. or higher required in the field of packaging and the like. Especially when the phenol novolak type is used in combination with a basic thermosetting accelerator, the acrylonitrile-butadiene rubber can be simultaneously cross-linked to form a three-dimensional shaded cured product, so that the insulating cured product having a higher glass transition temperature. Can be obtained. In this case, in consideration of the curability and heat resistance of the resin, the phenol novolak type and the basic thermosetting accelerator are each added to 100 parts of the epoxy resin by 15 parts.
It is preferable to add 〜40% by weight and 2 to 5% by weight of a basic thermosetting accelerator.

[0013]

EXAMPLE 1 A resin composition having the following composition was dried on Sepanium M25 (trade name, manufactured by Sun Aluminum Co., Ltd.), a 25-μm-thick aluminum foil whose surface was release-treated with a release agent. Is applied at a speed of 1.0 m / min so that the
Drying was performed under the conditions of minutes to prepare an insulating adhesive film. -Cresol novolak type epoxy resin: ESCN-195 (manufactured by Sumitomo Chemical Co., Ltd., trade name) ... 50 parts by weight-Bis A type epoxy resin: EP-828 (manufactured by Yuka Shell Epoxy Co., Ltd., trade name) ... 20 parts by weight -Acrylonitrile butadiene rubber: PNR-1H (manufactured by JSR Corporation, trade name) ... 7 parts by weight-Phenol novolak resin: PS-5805 (manufactured by Gunei Chemical Industry Co., Ltd., trade name) ... 10 parts by weight-Thermosetting accelerator : CP-66 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) ... 2 parts by weight-Aluminum hydroxide: Heidilite H-42M (trade name, manufactured by Showa Denko KK) ... 10 parts by weight-Methyl ethyl ketone ... 50 parts by weight

Example 2 A resin composition having the following composition was applied in the same manner as in Example 1 to produce an insulating adhesive film. -Cresol novolak type epoxy resin: ESCN-195 (manufactured by Sumitomo Chemical Co., Ltd., trade name) ... 45 parts by weight-Bis A type epoxy resin: EP-828 (manufactured by Yuka Shell Epoxy Co., Ltd., trade name) ... 25 parts by weight -Acrylonitrile butadiene rubber: XER-31 (trade name, manufactured by JSR Corporation) ... 10 parts by weight-Phenol novolak resin: HP-180R (trade name, manufactured by Hitachi Chemical Co., Ltd.) ... 10 parts by weight-Thermosetting accelerator: CP-66 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) ... 2 parts by weight-Aluminum hydroxide: Heidilite H-42M (trade name, manufactured by Showa Denko KK) ... 10 parts by weight-Methyl ethyl ketone ... 50 parts by weight

Example 3 An insulating adhesive film was prepared by applying a resin composition having the following composition in the same manner as in Example 1. -Cresol novolak epoxy resin: KRM-2650 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) ... 40 parts by weight-Bis A type epoxy resin: EP-815 (trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) ... 30 weight parts Part: Acrylonitrile butadiene rubber: PNR-1H (manufactured by JSR Corporation, trade name) ... 5 parts by weight-Phenol novolak resin: PS-5805, (manufactured by Gunei Chemical Industry Co., Ltd., trade name) ... 10 parts by weight-Thermosetting Accelerator: CP-66 (manufactured by Asahi Denka Kogyo Co., Ltd., trade name) ... 2 parts by weight-Aluminum hydroxide: Heidilite H-42M (manufactured by Showa Denko KK, trade name) ... 10 parts by weight-Methyl ethyl ketone ... 50 parts by weight Department

Comparative Example 1 The following resin composition was prepared and applied in the same manner as in Example 1 to prepare an insulating adhesive film. Cresol novolak type epoxy resin: KRM-2650 (manufactured by Asahi Denka Kogyo Co., Ltd., trade name) 40 parts by weight Bis A type epoxy resin: (solid at 25 ° C.) EP-1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts by weight-Acrylonitrile butadiene rubber: PNR-1H (trade name, manufactured by JSR Corporation) ... 10 parts by weight-Phenol novolak resin: HP-180R (trade name, manufactured by Hitachi Chemical Co., Ltd.) ... 10 parts by weight Part-Thermal curing accelerator CP-66 (made by Asahi Denka Kogyo Co., Ltd., trade name) ... 2 parts by weight-Aluminum hydroxide: Hijilite H-42M (manufactured by Showa Denko KK, trade name) ... 10 parts by weight-Methyl ethyl ketone ... 50 parts by weight

Comparative Example 2 The following resin composition was prepared and applied in the same manner as in Example 1 to prepare an insulating adhesive film. -Cresol novolak type epoxy resin: ESCN-195 (manufactured by Sumitomo Chemical Co., Ltd., trade name) ... 70 parts by weight-Acrylonitrile butadiene rubber: XER-31 (manufactured by JSR Corporation, trade name) ... 20 parts by weight-Phenol novolak resin: Poise-5805 (manufactured by Gunei Chemical Industry Co., Ltd., trade name) ... 10 parts by weight-Thermosetting accelerator: CP-66 (manufactured by Asahi Denka Kogyo Co., Ltd., trade name) ... 2 parts by weight-Aluminum hydroxide: Heidilite H-42M (manufactured by Showa Denko KK, trade name) ... 10 parts by weight ・ Methyl ethyl ketone ... 50 parts by weight

The properties of the additive adhesive film produced as described above were evaluated by the following items. Film flexibility The insulating resin side of the coated insulating adhesive film was bent at 180 °, and after being creased, returned to a flat surface, and the occurrence of cracks in the film near the crease was visually observed.・ Glass transition temperature 170 ° C for 90 minutes + 180 ° C
A cured product was prepared by heating under the conditions of 120 minutes, and the glass transition temperature was measured by a TMA tension method. -Plating peel strength, interlayer insulation resistance A sample for evaluating the characteristics of a multilayer printed wiring board was prepared and evaluated by the following method. 1) Heat-pressing and laminating under vacuum (high-temperature holding temperature: 170 ° C., holding pressure: 3 MPa, holding time: 90 minutes) so that the insulating resin of the insulating adhesive film adheres to the surface on which the first circuit is formed. . 2) After laminating under vacuum pressure, the aluminum foil is removed. Next, alkaline potassium permanganate heated to 70 ° C. to chemically roughen the surface of the insulating resin (permanganate amount: 70 g)
/ L) solution for 10 minutes and a hydroxylamine sulfate neutralized solution for 5 minutes. 3) After the roughening treatment, a conductor was formed by electroless plating thinning and electroplating thickening, and then unnecessary portions of plated copper were removed to form a second circuit. 4) After-curing was performed at 180 ° C. for 120 minutes to obtain a sample of a multilayer printed wiring board, and the plating peel strength and the interlayer insulation resistance were evaluated. Table 1 summarizes the results of these characteristic evaluations.

[0019]

[Table 1]

[0020]

As described above, according to the present invention, an insulating adhesive film excellent in flexibility without lowering the glass transition temperature, a multilayer printed wiring board using the same, and a method of manufacturing the same will be described. can do.

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Claims (4)

[Claims] (1) a trifunctional or higher polyfunctional epoxy resin;
An insulating adhesive film comprising a bifunctional epoxy resin which is liquid at 5 ° C. and has a viscosity of 100 poise or less and acrylonitrile butadiene rubber. 2. A polyfunctional epoxy resin comprising 30 to 60% by weight,
The insulating adhesive film according to claim 1, wherein the bifunctional epoxy resin is 15 to 30% by weight and the acrylonitrile butadiene rubber is 5 to 12% by weight. 3. A multilayer printed circuit comprising an inner circuit board on which an inner circuit is formed, an insulating layer formed thereon, an outer circuit formed on the surface of the insulating layer, and a via hole connecting the inner circuit and the outer circuit. A printed wiring board, wherein the insulating layer is made of the insulating adhesive film according to claim 1. 4. The insulating adhesive film according to claim 1 is laminated and adhered to an inner circuit board on which an inner circuit is formed,
A method for manufacturing a multilayer printed wiring board in which a via hole reaching an inner layer circuit is formed, an outer layer circuit is formed on the surface of an insulating adhesive film, and an electrical connection is made between the outer layer circuit and the inner layer circuit.