JP2008266513A - Curable resin composition, prepreg, laminate, metal foil with adhesive layer, film sheet, and printed wiring board using these materials - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printed wiring board which can be produced in a good yield, and, by impregnating a thin fiber substrate with a resin having excellent adhesion to a metal foil and a fiber substrate and high flexibility, has superior dimensional stability and heat resistance, is bendable, and prevents a resin powder from falling upon processing, as well as to provide a prepreg, a laminate, a metal foil with an adhesive layer, a film sheet and a printed wiring board using these. <P>SOLUTION: This curable resin composition comprises an acrylic rubber (A), a thermosetting resin (B) and a filler (C). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a curable resin composition, a prepreg, a laminate, a metal foil with an adhesive layer, a film sheet, and a printed wiring board using these.

  In recent years, the mounting density of electronic components has increased as electronic devices have been rapidly reduced in size and performance. For this reason, demands for multilayered printed wiring boards, reduced through-hole diameters, and reduced hole spacing are increasing, and printed wiring boards are strictly required to have electrical insulation characteristics. As the electrically insulating resin, thermosetting resins such as phenol resins, epoxy resins, polyimide resins, polyamideimide resins, bismaleimide-triazine resins are widely used, and thermoplastic resins such as fluororesins and polyphenol ether resins are used. A resin may be used.

  On the other hand, with the progress of miniaturization and high density of printed wiring boards, the mounting form is changed from a pin insertion type to a surface mounting type, and further an area array represented by BGA (ball grid array) using a plastic substrate. Progressing to mold. In a substrate on which a bare chip such as a BGA is directly mounted, the connection between the chip and the substrate is generally performed by wire bonding by thermosonic bonding. For this reason, the board | substrate which mounts a bare chip will be exposed to 150 degreeC or more high temperature, and a certain amount of heat resistance is required for the electrically insulating resin in a board | substrate. In addition, it may be required that a so-called repair is possible, in which a chip once mounted is removed from the substrate. In the repair, when removing the mounted chip and mounting the chip again, the same amount of heat is applied to the substrate as in the first chip mounting. Therefore, a substrate that requires repairability is required to have improved thermal shock resistance that can withstand the heat history that is cyclically applied. In general, however, an electrically insulating resin has a fiber base due to the lack of thermal shock resistance. In some cases, there was a problem such as peeling between the material and the resin. Also in this respect, high heat resistance is required for the electrically insulating resin in the substrate.

  In addition, from the viewpoint of environmental problems, the lead-free solder advances, and the melting temperature of the solder increases, so that higher heat resistance is required for the substrate. The demand for halogen-free materials has also increased, making it difficult to use brominated flame retardants.

JP 2003-55486 A

  The present invention eliminates the above-mentioned problems of the prior art, and impregnates a thin fiber substrate with a highly flexible resin having excellent adhesion to a metal foil or a fiber substrate, thereby providing dimensional stability and heat resistance. Excellent printed circuit board that can be bent when used as a printed wiring board, prevents the resin powder from falling off during processing, and has a good yield, and a curable resin composition that gives the printed wiring board, prepreg, and lamination A plate, a metal foil with an adhesive layer, and a film sheet are provided.

The present invention relates to the following.
1. A curable resin composition comprising an acrylic rubber (A), a thermosetting resin (B), and a filler (C).
2. Item 2. The curable resin composition according to Item 1, wherein the weight ratio (A) / (C) of the acrylic rubber (A) and the filler (C) is in the range of 0.1 to 4.0.
3. Item 3. The curable resin composition according to Item 1 or 2, which is halogen-free.
4). Item 4. The curable resin composition according to any one of Items 1 to 3, wherein the acrylic rubber (A) has a glycidyl group and has an epoxy value of 2 to 18 equivalents / kg.
5. Item 5. The curable resin composition according to any one of Items 1 to 4, wherein the acrylic rubber (A) has a weight average molecular weight of 10,000 to 2,000,000.
6). Item 6. The curable resin composition according to any one of Items 1 to 5, wherein the thermosetting resin (B) comprises an epoxy resin or a phenol resin.
7). Item 7. The curable resin composition according to Item 6, wherein the phenol resin has two or more phenolic hydroxyl groups.
8). A prepreg obtained by impregnating and drying the curable resin composition according to any one of Items 1 to 7 on a fiber substrate.
9. Item 9. The prepreg according to Item 8, wherein the fiber substrate has a thickness of 100 µm or less.
10. A laminate obtained by laminating a predetermined number of the prepregs according to Item 8 or 9, and heating and pressing the laminate.
11. Metal foil with an adhesive layer which has an adhesive layer which consists of metal foil and the curable resin composition as described in any one of Claims 1-7 provided on the said metal foil.
12 The film sheet which consists of curable resin composition as described in any one of claim | item 1 -7.
13. A laminate comprising the metal foil with an adhesive layer according to Item 11 or the film sheet according to Claim 12.
14 Item 14. A printed wiring board obtained by subjecting the laminated board according to Item 10 or 13 to wiring processing.

  The metal-clad laminate and printed wiring board obtained by the prepreg in the present invention can be arbitrarily bent, are halogen-free and show flame retardancy, have little powder fall, and are excellent in insulation reliability, dimensional stability, and heat resistance.

  The acrylic rubber (A) is usually a rubber made of a copolymer having a (meth) acrylic acid alkyl ester as a monomer. The copolymer is generally produced by copolymerizing a (meth) acrylic acid alkyl ester and a compound having a double bond. In the (meth) acrylic acid alkyl ester, the alkyl group is preferably an alkyl group having 1 to 20 carbon atoms which may have a substituent. Examples of the substituent of the alkyl group include an alicyclic group, a glycidyl group, a C1-C6 alkyl group having a hydroxyl group, and a nitrogen-containing cyclic group. The compound having a double bond is not particularly limited as long as it is a compound that can be copolymerized with a (meth) acrylic acid alkyl ester.

  Specific examples of the (meth) acrylic acid alkyl ester include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate, ethylene glycol methyl ether acrylate, Cyclohexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobornyl acrylate, acrylate amide, isodecyl acrylate, octadecyl acrylate, lauryl acrylate, allyl acrylate, N-vinylpyrrolidone acrylate, methacryl Methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, isobutyl methacrylate, methacrylate Lenglycol methyl ether, cyclohexyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, isobornyl methacrylate, methacrylamide, isodecyl methacrylate, octadecyl methacrylate, lauryl methacrylate, allyl methacrylate, N methacrylate -Vinylpyrrolidone, acrylonitrile, dimethylaminoethyl and the like can be exemplified.

  The acrylic rubber preferably has a glycidyl group, and glycidyl (meth) acrylate is preferably used as the (meth) acrylic ester. The epoxy value of the acrylic rubber can be adjusted by appropriately adjusting the copolymerization ratio when copolymerizing glycidyl (meth) acrylate and another monomer copolymerizable therewith.

  The epoxy value of the acrylic rubber is preferably 2 to 18 equivalents / kg, more preferably 2 to 8 equivalents / kg. If the epoxy value is less than 2 equivalents / kg, the heat resistance of the substrate tends to decrease due to a decrease in the glass transition temperature of the cured product. Dimensional stability tends to decrease. Usually, an acrylic rubber having an epoxy value of 2 to 18 equivalents / kg is obtained by setting the ratio of other monomers to 5 to 15 parts by weight with respect to 100 parts by weight of glycidyl (meth) acrylate.

  As a commercial item of acrylic rubber having an epoxy group, for example, “HTR-860” (manufactured by Nagase ChemteX Corporation, trade name, epoxy value 3.05) is available. The weight average molecular weight of the acrylic rubber is preferably 10,000 to 2,000,000, more preferably 50,000 to 1,500,000 from the viewpoint of improving heat resistance, and 30 to 150, from the viewpoint of reducing the prepreg tack. More preferably, it is 10,000. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) analysis and means a standard polystyrene equivalent value. The GPC analysis can be performed using tetrahydrofuran (THF) as a solution.

  The acrylic rubber is generally obtained by radical polymerization using a radical polymerization initiator that generates radicals. Examples of radical initiators include persulfates such as azobisisobutyronitrile (AIBN), tert-butyl perbenzoate, benzoyl peroxide, lauroyl peroxide, potassium persulfate, cumene hydroperoxide, t-butyl hydroperoxide, Dicumyl peroxide, di-t-butyl peroxide, 2,2′-azobis-2,4-dimethylvaleronitrile, t-butyl perisobutyrate, t-butyl perpivalate, hydrogen peroxide / ferrous salt Examples thereof include sulfate / sodium acid sulfite, cumene hydroperoxide / ferrous salt, benzoyl peroxide / dimethylaniline, and the like. These may be used alone or in combination.

  As needed, acrylic rubber includes cross-linking agents such as isocyanate and melamine, polymer compounds such as epoxy resins, flame retardants such as rubber elastomers and phosphorus compounds, inorganic fillers such as silica, conductive particles, cups You may mix | blend and use a ring agent, a pigment, a leveling agent, an antifoamer, an ion trap agent, etc.

  Examples of the thermosetting resin include an epoxy resin and a phenol resin. Polyfunctional epoxy compounds that are epoxy resins or compounds having an epoxy group are bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, biphenyl type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins. Bisphenol A novolak type epoxy resin, naphthalene skeleton containing epoxy resin, aralkylene skeleton containing epoxy resin, phenol biphenyl aralkyl type epoxy resin, phenol salicylaldehyde novolak type epoxy resin, lower alkyl group substituted phenol salicylaldehyde novolak type epoxy resin, dicyclopentadiene Examples include skeleton-containing epoxy resins, polyfunctional glycidylamine type epoxy resins, and polyfunctional alicyclic epoxy resins. It can be used alone or in combination of two or more. Moreover, NC-3000H (Nippon Kayaku Co., Ltd. trade name) as a biphenyl aralkyl type epoxy resin, ZX-1548 (Toto Kasei Co., Ltd. trade name) as a phosphorus-containing epoxy resin, and EPICLON N-660 (large) as a cresol novolac type epoxy resin Nippon Ink Co., Ltd. trade name).

  The phenol resin is preferably a polyfunctional phenol resin having two or more phenolic hydroxyl groups per molecule as a crosslinkable functional group. As a phenol resin, the compound containing multiple phenol rings or cresol rings, such as a phenol resin and a cresol resin, is mentioned, for example. You may use these in combination of 2 or more type as needed. Examples of commercially available phenolic resins include aminotriazine-modified novolak resin Phenolite LA-1356 (trade name, manufactured by Dainippon Ink Co., Ltd.) and biphenyl novolac MEH-7851 (trade name, manufactured by Meiwa Kasei Co., Ltd.). ).

  The phosphorus compound is contained in the curable resin composition as a flame retardant. Examples of phosphorus compounds include monomeric phosphate esters, condensed phosphate esters, red phosphorus, polyphosphoric acid, and phosphazene compounds. These may be used alone or in combination of two or more.

  Examples of commercially available phosphorous compounds include Leophos TPP (trade name of Ajinomoto Fine-Techno Co., Ltd.) as a monomer type phosphate ester, Reofos RDP, BAPP (trade name of Ajinomoto Fine-Techno Co., Ltd.), and phosphorus-containing filler. Is OP930 (trade name of Clariant Japan Co., Ltd.) HCA-HQ (trade name of Sanko Co., Ltd.), Red phosphorus is Novaquel (trade name of Rin Chemical Industry Co., Ltd.), Hishiguard (trade name of Nippon Chemical Industry Co., Ltd.), and polyphosphoric acid is PMP100 (Nissan Chemical Co., Ltd. trade name), Exorit OP 1311 (Clariant Japan Co., Ltd. trade name), and Phosphazen are available as SBP100 (Otsuka Chemical Co., Ltd. trade name). The phosphorus content in the resin composition is preferably in the range of 0.1 to 10% by weight. If it is less than 0.1% by weight, the flame retardancy is lowered, and if it exceeds 10% by weight, the flexibility is lowered.

  Examples of the thermosetting accelerator include amines and imidazoles. Examples of amines include dicyandiamide, diaminodiphenylethane, guanylurea and the like, and imidazoles include 2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2. Examples thereof include imidazole compounds such as -phenylimidazole and 1-cyanoethyl-2-phenylimidazolium trimellitate, and benzimidazole. Although the compounding quantity of a hardening accelerator can be determined according to the total amount of the oxirane ring in a resin composition, it is generally 0.01-10 weight part in 100 weight part of resin solid content of a resin composition. It is preferable.

  The prepreg is produced by impregnating a base material with a varnish of a heat resistant resin composition and drying it in a range of 80 ° C to 180 ° C. Although a base material will not be restrict | limited especially if it is used when manufacturing a metal-clad laminated board and a multilayer printed wiring board, Usually fiber base materials, such as a woven fabric and a nonwoven fabric, are used. The material of the fiber substrate is glass, alumina, asbestos, boron, silica alumina glass, silica glass, tyranno, silicon carbide, silicon nitride, zirconia, and other inorganic fibers, aramid, polyether ether ketone, polyether imide, polyether sal There are organic fibers such as phon, carbon and cellulose, and mixed papers, and glass cloths of 100 μm or less are particularly used. Furthermore, by using a glass cloth having a thickness of 50 μm or less, a printed wiring board that can be bent arbitrarily can be obtained, and dimensional changes associated with temperature, moisture absorption, etc. in the manufacturing process can be reduced.

  The production conditions of the prepreg are not particularly limited, but it is preferable that the solvent used for the varnish is volatilized by 80% by weight or more. For this reason, there is no restriction | limiting also in a manufacturing method, drying conditions, etc., the temperature at the time of drying is 80 to 180 degreeC, and time does not have a restriction | limiting in particular by balance with the gelatinization time of a varnish. Moreover, it is preferable that the amount of impregnation of a varnish shall be 30-80 weight% with respect to a varnish solid content and the total amount of a base material.

  The manufacturing method of an insulating board, a laminated board, or a metal-clad laminated board is as follows, for example. The prepreg or a plurality of the prepregs in the present invention are laminated, and a metal foil is laminated on one side or both sides as necessary, usually at 130 to 250 ° C., preferably at a temperature in the range of 150 ° C. to 210 ° C., usually 0.5 to An insulating plate, a laminate or a metal-clad laminate can be produced by heat and pressure molding at a pressure in the range of 20 MPa, preferably 1 to 8 MPa. By using a metal foil to form a metal-clad laminate, a circuit (wiring) process can be applied to this to obtain a printed wiring board.

  As the metal foil used in the present invention, a copper foil or an aluminum foil is generally used, but one having a thickness of 1 to 200 μm which is usually used for a laminate can be used. Also, a three-layer structure in which nickel, nickel-phosphorus, nickel-suds alloy, nickel-iron alloy, lead, lead-tin alloy, etc. are used as intermediate layers, and 0.5 to 15 μm copper layers and 10 to 300 μm copper layers are provided on both sides. Or a two-layer composite foil in which aluminum and copper foil are combined. The “powder falling” as used in the present invention means peeling or detachment of the filler component.

Examples are described below, but the present invention is not limited to these examples.
Example 1
20g of HTR860-P3 (trade name of Nagase ChemteX Co., Ltd.) as an acrylic rubber, 60g of EPICLON N-660 (trade name of Dainippon Ink Co., Ltd.) as an epoxy resin, and MEH-7851 (trade name of Meiwa Kasei Co., Ltd.) as a curing agent 15 g, 0.2 g of 2-phenylimidazole as a curing accelerator, 20 g of PMP100 (product name of Nissan Chemical Co., Ltd.) as a phosphorus compound, 10 g of ALH (product name of Kawai Lime Industry Co., Ltd.) as a filler, diluted to 700 cP with addition of methyl ethyl ketone, A resin composition varnish was prepared.

Example 2
A resin composition varnish was produced in the same manner as in Example 1 except that the blending amount of the acrylic rubber in Example 1 was changed to 40 g.

Example 3
A resin composition varnish was prepared in the same manner as in Example 1 except that the blending amount of the acrylic rubber in Example 1 was changed to 60 g.

Example 4
A resin composition varnish was produced in the same manner as in Example 1 except that the amount of the acrylic rubber in Example 1 was changed to 80 g.

Example 5
A resin composition varnish was produced in the same manner as in Example 1 except that the amount of the filler in Example 1 was changed to 20 g.

Example 6
A resin composition varnish was prepared in the same manner as in Example 1 except that the amount of the acrylic rubber in Example 1 was changed to 40 g and the amount of the filler was changed to 40 g.

Comparative Example 1
A resin composition varnish was produced in the same manner as in Example 1 except that the acrylic rubber of Example 1 was not blended.

Comparative Example 2
A resin composition varnish was prepared in the same manner as in Example 1 except that the amount of the acrylic rubber in Example 1 was 10 g and the amount of the filler was 100 g.

(1) Production of prepreg and copper-clad laminate After impregnating the varnish produced in Examples 1 to 6 and Comparative Examples 1 and 2 into a glass cloth 1037 having a thickness of 0.028 mm (trade name, manufactured by Asahi Schavel Co., Ltd.), 120 A prepreg was obtained by heating and drying at 20 ° C. for 20 minutes.
Overlap the eight prepregs on both sides with 18μm thick electrolytic copper foil F2-WS-18 (trade name, manufactured by Furukawa Circuit Foil Co., Ltd.) so that the adhesive surface is combined with the prepreg, and bend it at 200 ° C for 30 minutes under 4MPa vacuum press condition. A double-sided copper-clad laminate for evaluation tests of characteristics, solder heat resistance, and copper foil adhesion was produced.

(2) Measuring method Evaluation of powder omission produced a sample piece by cutting a prepreg into a 20 cm square. Hand grinding was performed on the glass plate for 1 minute, and powder fall was evaluated by the amount of powder on the glass plate. “O” indicates that there was no powder falling, and “X” indicates that there was powder falling.
The copper foil peel strength was a sample in which a double-sided copper-clad laminate was used and a 1 mm wide copper foil line was formed by etching. The strength when the copper foil line was peeled off at a speed of 50 mm / min in the 90 ° direction was measured, and the copper foil peeling strength was obtained.
The characteristic results obtained by the above Examples and Comparative Examples are shown in Table 1 below.

  Moreover, as a result of measuring the content of each halogen element in the resin composition used in each example according to the JPCA standard (JPCA-ES-01-1999), the content of each of these halogen elements was 0.25. % By weight or less. Furthermore, as a result of measuring the halogen content of the double-sided copper-clad laminate obtained in each Example according to the JPCA standard (JPCA-ES-01-1999), the bromine content is 0.02% by weight or less, The chlorine content was 0.01% by weight or less, and the halogen-free standard of JPCA was 0.09% by weight or less.

Claims (14)

  A curable resin composition comprising an acrylic rubber (A), a thermosetting resin (B), and a filler (C).   The curable resin composition according to claim 1, wherein the weight ratio (A) / (C) of the acrylic rubber (A) and the filler (C) is in the range of 0.1 to 4.0.   The curable resin composition according to claim 1, which is halogen-free.   The curable resin composition according to any one of claims 1 to 3, wherein the acrylic rubber (A) has a glycidyl group and has an epoxy value of 2 to 18 equivalents / kg.   The curable resin composition as described in any one of Claims 1-4 whose weight average molecular weights of an acrylic rubber (A) are 10,000-2 million.   The curable resin composition as described in any one of Claims 1-5 in which a thermosetting resin (B) contains an epoxy resin or a phenol resin.   The curable resin composition according to claim 6, wherein the phenol resin has two or more phenolic hydroxyl groups.   A prepreg obtained by impregnating and drying the curable resin composition according to any one of claims 1 to 7 on a fiber substrate.   The prepreg of Claim 8 whose thickness of a fiber base material is 100 micrometers or less.   A laminate obtained by laminating a predetermined number of the prepregs according to claim 8 or 9 and heating and pressing the laminate.   Metal foil with an adhesive layer which has an adhesive layer which consists of metal foil and the curable resin composition as described in any one of Claims 1-7 provided on the said metal foil.   The film sheet which consists of a curable resin composition as described in any one of Claims 1-7.   The laminated board which uses the metal foil with an adhesive layer of Claim 11, or the film sheet of Claim 12.   The printed wiring board formed by wiring-processing the laminated board of Claim 10 or 13.