JP2005112981A - Low-permittivity resin composition, prepreg using the same, metal-clad laminate, and printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition having such high heat resistance as to permit soldering with a lead-free solder and having excellent permittivity characteristics, to provide a prepreg using the same, to provide a metal-clad laminate, and to provide a printed circuit board. <P>SOLUTION: The resin composition comprises (a) a difunctional polyphenylene ether resin represented by structural formula (1) (wherein m and n are each an integer of 1 or greater; X is an optionally substituted divalent chain or cyclic hydrocarbon skeleton; R<SP>1</SP>is a hydrogen atom or a monovalent functional group; R<SP>2</SP>, R<SP>3</SP>, R<SP>8</SP>, and R<SP>9</SP>, which may be the same or different from each other, are 1 to 6C hydrocarbon groups; and R<SP>4</SP>, R<SP>5</SP>, R<SP>6</SP>, and R<SP>7</SP>, which may be the same as or different from each other, are hydrogen atoms or 1 to 6C hydrocarbon groups), (b) a thermosetting resin, and (c) a curing agent for the thermosetting resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a resin composition, a prepreg using the resin composition, a metal-clad laminate, and a printed wiring board.

In recent years, information terminal electronic devices such as personal computers and mobile phones are required to process large amounts of information at high speed, and the frequency of electrical signals handled here is increasing. Accordingly, laminates used in these electronic devices are required to have characteristics corresponding to high frequencies, that is, low dielectric constant and low dielectric loss tangent.
In addition, as the awareness of environmental issues increases, the leakage of lead used in solder materials to the natural environment has become a problem, and the use of lead-free solder has been started as part of the countermeasure.
Along with this, the soldering temperature is increased by about 10 to 15 ° C. as compared with the conventional one, and further higher heat resistance is required for the laminated plate material.
In order to satisfy the high frequency response among these requirements, polyphenylene ether (PPE) is used as a low dielectric constant resin material for laminates. This PPE is a thermoplastic resin, and is used together with a thermosetting resin such as an epoxy resin and its curing agent in a laminated board application in order to impart heat resistance. However, since PPE generally has a relatively high molecular weight of 10000 to 50000, its compatibility with the thermosetting resin and its curing agent is low. Therefore, as a method for improving the compatibility, a method in which a high molecular weight PPE and a bifunctional phenolic compound are redistributed under a radical reaction initiator and the generated low molecular weight PPE is used (Japanese Patent Laid-Open No. 2001-261791). And a method using a modified epoxy resin obtained by reacting an epoxy resin with a phenolic hydroxyl group of a low molecular weight PPE obtained by the redistribution reaction (Japanese Patent No. 3265984) has been proposed.

JP 2001-261791 A Japanese Patent No. 3265984

However, when the former method is used, the molecular weight of PPE obtained by the redistribution reaction varies widely, and the product has a relatively large amount of high molecular weight PPE and monofunctional PPE, so that bifunctional PPE can be obtained efficiently. Therefore, the cured product containing this product has a low crosslinking density, and the laminate using this resin composition satisfies the low-temperature solder heat resistance (260 ° C.), which is an index for dealing with conventional lead-containing solder. However, there is a problem that high temperature soldering heat resistance (288 ° C.), which is an index for dealing with lead-free solder, is not satisfied due to blistering. Also, the latter method has a problem that it is inferior in high-temperature solder heat resistance because it cannot efficiently obtain a bifunctional low-molecular PPE as in the former method.
The present invention solves the above-mentioned problems of the prior art and provides a resin composition excellent in high heat resistance and dielectric properties corresponding to lead-free solder, and a prepreg, a metal-clad laminate, and a printed wiring board using the same. To do.

According to the first aspect of the present invention, (a) a bifunctional polyphenylene ether resin represented by structural formula (1) (in structural formula (1), m and n represent an integer of 1 or more, and X represents , A divalent chain-like or cyclic hydrocarbon skeleton which may have a substituent, R ¹ is a hydrogen atom or a monovalent functional group, R ² , R ³ , R ⁸ and R ⁹ are the same or different. Or a hydrocarbon having 1 to 6 carbon atoms, R ⁴ , R ⁵ , R ⁶ and R ⁷ may be the same or different hydrogen atoms or hydrocarbons having 1 to 6 carbon atoms), (b) thermosetting And (c) a resin composition comprising a thermosetting resin curing agent.

請求項２に記載の発明は、構造式(１)で示される２官能ポリフェニレンエーテル樹脂のＲ^１が、水素原子またはグリシジル基であり，かつ、グリシジル基の場合、２官能ポリフェニレンエーテルに含有される加水分解性塩素の濃度が１００〜６００重量ｐｐｍである請求項１に記載の樹脂組成物である。
請求項３に記載の発明は、構造式(１)で示される２官能ポリフェニレンエーテル樹脂の数平均分子量が、８００〜６０００である請求項１または請求項２に記載の樹脂組成物である。
請求項４に記載の発明は、請求項１ないし請求項３のいずれかに記載の樹脂組成物をワニスとして基材に含浸・乾燥させて得られるプリプレグである。
請求項５に記載の発明は、請求項４に記載のプリプレグ、または、そのプリプレグを複数枚積層した積層体の片面または両面に金属箔を積層し加熱加圧して得られる金属張積層板である。
請求項６に記載の発明は、請求項５に記載の金属張積層板に回路加工を施して得られる印刷配線板である。

In the invention according to claim 2, when R ^{1 of the} bifunctional polyphenylene ether resin represented by the structural formula (1) is a hydrogen atom or a glycidyl group, and is a glycidyl group, the bifunctional polyphenylene ether is contained. The resin composition according to claim 1, wherein the concentration of hydrolyzable chlorine is 100 to 600 ppm by weight.
Invention of Claim 3 is a resin composition of Claim 1 or Claim 2 whose number average molecular weights of bifunctional polyphenylene ether resin shown by Structural formula (1) are 800-6000.
The invention described in claim 4 is a prepreg obtained by impregnating and drying a base material using the resin composition according to any one of claims 1 to 3 as a varnish.
The invention according to claim 5 is a metal-clad laminate obtained by laminating metal foil on one or both sides of the prepreg according to claim 4 or a laminate in which a plurality of the prepregs are laminated and heating and pressing. .
The invention described in claim 6 is a printed wiring board obtained by subjecting the metal-clad laminate according to claim 5 to circuit processing.

  The resin composition of the present invention, a prepreg using the same, a metal-clad laminate obtained using the same, and a printed wiring board using the same exhibit excellent heat resistance and dielectric properties. That is, it is excellent in high-temperature solder heat resistance (288 ° C.), which is an index for dealing with lead-free solder, and exhibits heat resistance without causing blistering. Further, it has excellent heat resistance, and has excellent low dielectric constant and low dielectric loss tangent dielectric characteristics applicable to high frequency applications.

Hereinafter, the present invention will be described in detail.
The bifunctional polyphenylene ether resin (hereinafter referred to as bifunctional PPE) represented by the structural formula (1) used in the present invention is not particularly limited except that it has functional groups at both ends. The number average molecular weight of the bifunctional PPE is preferably 800 to 6000. When the number average molecular weight is less than 800, the number of functional groups per molecule of the bifunctional PPE increases, and these functional groups generally deteriorate the dielectric properties, and thus there is a possibility that the target dielectric properties cannot be obtained. Moreover, when the number average molecular weight of bifunctional PPE is less than 800, heat resistance may fall resulting from this. When the average molecular weight exceeds 6000, the compatibility with other resins in the resin composition is lowered, and the appearance of the prepreg is deteriorated due to the lowering of the compatibility. In addition, since the number of functional groups per molecule of bifunctional PPE is reduced, the crosslink density of the cured product is lowered, and there is a risk of problems such as deterioration in heat resistance.

  When the functional groups at both ends of the bifunctional PPE are glycidyl groups, the concentration of hydrolyzable chlorine remaining during the production is preferably 100 to 600 ppm by weight. When the concentration of hydrolyzable chlorine exceeds 600 ppm by weight, the heat resistance may decrease due to the presence of residual chlorine. In addition, it is very difficult in terms of technical and cost to make the concentration of hydrolyzable chlorine 100 ppm or less. If the concentration is 600 ppm by weight or less, the influence on heat resistance is extremely small. If the concentration is 100 to 600 ppm by weight, it is preferable because both heat resistance and low cost can be achieved.

Examples of X representing a divalent chain or cyclic hydrocarbon skeleton which may have a substituent of the bifunctional polyphenylene ether resin represented by the structural formula (1) used in the present invention include, for example, bisphenol A and bisphenol F. , Diphenylmethane, diphenylethane skeleton and the like.
R ¹ is a hydrogen atom or a monovalent functional group. Examples of the functional group include a glycidyl group and a cyano group, and a hydrogen atom or a glycidyl group is preferable for the reason of reactivity and heat resistance.
R ² , R ³ , R ⁸ and R ⁹ are the same or different hydrocarbons having 1 to 6 carbon atoms, and examples thereof include alkyl groups such as methyl, ethyl and propyl groups, and phenyl groups. . R ⁴ , R ⁵ , R ⁶ and R ⁷ represent the same or different hydrogen atoms or hydrocarbons having 1 to 6 carbon atoms, and examples of the hydrocarbon having 1 to 6 carbon atoms include methyl group, ethyl And alkyl groups such as a propyl group and a phenyl group.
Among these, X is preferably a bisphenol A or bisphenol F skeleton, R ¹ is a hydrogen atom or a glycidyl group, and R ² -R ⁹ is a methyl group, an ethyl group, or a propyl group.

  Although the compounding quantity of bifunctional PPE is not restrict | limited in particular, 10-60 weight part is preferable with respect to 100 weight part of solid content total amount of the organic component in a resin composition. If the blending amount is less than 10 parts by weight, the desired dielectric properties may not be sufficiently obtained. If the blending amount exceeds 60 parts by weight, the ratio of the thermosetting resin in the resin composition is relatively reduced, so that the cured product is obtained. The crosslink density of the resin may be lowered, and the heat resistance may deteriorate.

  The (b) thermosetting resin used in the present invention is not particularly limited, and examples thereof include an epoxy resin, a polyimide resin, a triazine resin, a melamine resin, a phenol resin, a cyanate compound, and the like alone or Two or more types can be used. Among these, for example, when an epoxy resin is taken as an example, bisphenol A type epoxy resin, bisphenol AD type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, alicyclic epoxy resin, aliphatic chain epoxy resin , Phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, phenol biphenylene novolac type epoxy resin, bisphenol A novolac type epoxy resin, diglycidyl etherified product of biphenol, diglycidyl etherified product of naphthalenediol, phenol Diglycidyl etherified products, alcohol diglycidyl etherified products, alkyl substitution products thereof, hydrogenated products, etc. are used alone or from these two or more. It is possible to use.

The (c) curing agent used in the present invention is not particularly limited, but examples of the curing agent in the case of using an epoxy resin as a thermosetting resin include amine compounds, polyfunctional phenol compounds, and acid anhydrides. Compound, etc. are mentioned, and these are selected singly or in combination of two or more. Although the compounding quantity of a hardening | curing agent is not restrict | limited in particular, 0.01-5.0 equivalent is preferable with respect to the functional group of the main material of a thermosetting resin. Even when any thermosetting resin is used, a curing accelerator may be used. The curing accelerator in this case is not particularly limited. For example, imidazole compounds, organophosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts, and the like are used. These are selected. The blending amount of the curing accelerator is not particularly limited, but is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the total solid content of the organic component in the resin composition.
In addition, the resin composition used in the present invention may contain a catalyst, a flexible agent, a flame retardant, a filler, and the like as needed.

  The varnish of the resin composition of the present invention can be obtained by adding an organic solvent to the above compounded material as necessary and mixing them. The organic solvent used in the present invention is not particularly limited, but alcohol solvents such as methanol, ethanol, isopropyl alcohol and n-butanol, ketone solvents such as acetone, methyl ethyl ketone and cyclohexanone, and aromatic carbonization such as toluene and xylene. Hydrogen solvents, sulfur compound solvents such as dimethyl sulfoxide, amide solvents such as N-methylpyrrolidone, N-methylformaldehyde, N, N-dimethylformamide, cellosolv solvents such as methyl cellosolve, ethyl cellosolve, cellosolve acetate, etc. They can be used and are selected from these alone or in combination.

  The base material is impregnated with the varnish of the resin composition of the present invention, and further dried to produce a prepreg. Although it does not restrict | limit especially as a base material used for this invention, Usually, a woven fabric, a nonwoven fabric, etc. are used. The material of the substrate is not particularly limited, but inorganic fibers such as glass, alumina, silica alumina glass, silica glass, silicon carbide, and zirconia, and organic fibers such as aramid, polyetherimide, carbon, and cellulose are used. .

  The metal-clad laminate of the present invention can be obtained by stacking a metal foil on one side or both sides of the prepreg of the present invention or a laminate in which a plurality of the prepregs are laminated and press-molding them. The metal foil used in the present invention is not particularly limited, but copper foil, aluminum foil, and the like are used. The conditions for heat and pressure molding depend on the reactivity of the bifunctional polyphenylene ether resin and thermosetting resin with the curing agent, and therefore are selected according to the resin material used, and are usually 130 to 250 ° C., preferably 150 to A temperature in the range of 200 ° C., usually 0.5 to 20 MPa, preferably a pressure in the range of 1 to 8 MPa, usually a heating and pressing time in the range of 10 to 200 minutes, preferably 30 to 120 minutes is selected.

  The printed wiring board of the present invention can be obtained by subjecting a metal foil surface or a metal foil etched surface of the metal-clad laminate of the present invention to circuit processing.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
(Examples 1 to 5, Comparative Examples 1 and 2 and Reference Example 1)
Toluene was blended into the separable flask as a material and solvent in the blending amounts shown in Tables 1 and 2, and stirred at 100 ° C. for 60 minutes to obtain a resin composition varnish. Toluene was blended so that the solid content of the varnish was 50% by weight. The prepared varnish was impregnated into a 0.1 mm thick glass cloth (2116: trade name, manufactured by Asahi Sebel Co., Ltd.), then heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 50% by weight. Four prepregs are stacked, and 18 μm thick copper foil (GTS-18: manufactured by Furukawa Circuit Foil Co., Ltd., trade name) is placed on both sides of the prepreg and heated and pressurized under vacuum at 200 ° C., 3 MPa for 60 minutes. A copper clad laminate was produced by molding.

Bifunctional PPE (1): Asahi Kasei Corporation (terminal hydroxyl group, number average molecular weight Mn984, hydroxyl group equivalent 436)
Bifunctional PPE (2): Asahi Kasei Corporation (terminal glycidyl group, number average molecular weight Mn1040, epoxy equivalent 515, residual chlorine concentration 450 ppm by weight)
Bifunctional PPE (3): manufactured by Japan Epoxy Resin Co., Ltd. (terminal glycidyl group, number average molecular weight Mn5419, epoxy equivalent 1726, residual chlorine concentration 320 ppm by weight)
Bifunctional PPE (4): Asahi Kasei Corporation (terminal glycidyl group, number average molecular weight Mn960, epoxy equivalent 498, residual chlorine concentration 3542 weight ppm)
Monofunctional PPE: SA120, manufactured by GE Plastics, trade name (terminal hydroxyl group, number average molecular weight Mn2350)
Thermosetting resin: ESCN-195, manufactured by Sumitomo Chemical Co., Ltd., trade name (cresol novolac type epoxy resin, epoxy equivalent: 195)
Curing agent: HP-850N, manufactured by Hitachi Chemical Co., Ltd., trade name (phenol novolac resin, hydroxyl group equivalent: 108)
Curing accelerator: Curesol 2E4MZ, trade name (2-ethyl-4-methylimidazole) manufactured by Shikoku Kasei Kogyo Co., Ltd.

(Evaluation of solder heat resistance)
Solder heat resistance is obtained by holding a test piece obtained by removing the copper foil of the produced copper-clad laminate by etching and cutting it to a size of 50 mm × 50 mm in a pressure cooker tester (121 ° C., 0.22 MPa) for 2 hours. The film was immersed in a solder at 260 ° C. or 288 ° C. for 20 seconds, and the appearance was visually evaluated. The results are shown in Tables 1 and 2. “OK” in the table means that there is no mesling (resin peeling due to thermal strain at the overlapping portion of the glass fiber weave) and no blistering, and NG means that mesling or blistering has occurred. Show.

(Evaluation of dielectric properties)
The relative dielectric constant and dielectric loss tangent were measured by the triplate structure linear line resonator method. For the test piece, two copper-clad laminates cut to a size of 50 mm × 200 mm were prepared, the copper foil of one copper-clad laminate was etched on one side, and one side of the other copper-clad laminate was etched. A strip line (line length 200 mm) having a width of 0.8 mm was formed. The etched surfaces of the two copper-clad laminates are combined into a strip line, and the resonance frequency and attenuation constant are measured at 25 ° C. with a vector network analyzer (Hewlett Packard, HP-8722C). Dielectric constant and dielectric loss tangent were calculated.

  As is apparent from Table 1, it was confirmed that Examples 1 to 5 of the present invention can achieve both solder heat resistance and dielectric properties by using bifunctional PPE as compared with the comparative example. On the other hand, Comparative Example 1 shown in Table 2 is inferior in relative dielectric constant and dielectric loss tangent as compared with Examples because it does not contain PPE which is a low dielectric constant material. On the other hand, since Comparative Example 2 contains monofunctional PPE, the solder heat resistance at 288 ° C. is inferior to that of the Example. Although the reference example 1 uses bifunctional PPE, since the chlorine concentration is high, it is slightly inferior in solder heat resistance as compared with the examples.

Claims (6)

(a) Bifunctional polyphenylene ether resin represented by structural formula (1) (in structural formula (1), m and n represent an integer of 1 or more, and X represents a divalent optionally having substituent. R ¹ is a hydrogen atom or a monovalent functional group, R ² , R ³ , R ⁸ and R ⁹ are the same or different hydrocarbons having 1 to 6 carbon atoms, R 1 ⁴ , R ⁵ , R ⁶ and R ⁷ are the same or different hydrogen atoms or hydrocarbons having 1 to 6 carbon atoms), (b) a thermosetting resin, and (c) a curing agent for the thermosetting resin. A resin composition comprising:

When R ^{1 of the} bifunctional polyphenylene ether resin represented by the structural formula (1) is a hydrogen atom or a glycidyl group, and the glycidyl group, the concentration of hydrolyzable chlorine contained in the bifunctional polyphenylene ether is 100 to The resin composition according to claim 1, which is 600 ppm by weight. The resin composition according to claim 1 or 2, wherein the bifunctional polyphenylene ether resin represented by the structural formula (1) has a number average molecular weight of 800 to 6000. A prepreg obtained by impregnating and drying a substrate with the resin composition according to claim 1 as a varnish. A metal-clad laminate obtained by laminating a metal foil on one side or both sides of a prepreg according to claim 4 or a laminate obtained by laminating a plurality of the prepregs, and heating and pressing the laminate. A printed wiring board obtained by subjecting the metal-clad laminate according to claim 5 to circuit processing.