JP2011012271A - Method of producing prepreg, prepreg, metal-clad laminate and printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition containing no halogen compound and having excellent flame-retardancy, heat resistance and metal foil peel strength; and to provide a prepreg, a metal foil-clad laminate, and a printed wiring board, using the composition.SOLUTION: The resin composition is prepared by including (a) a phosphinate of formula (1) or a diphosphinate of formula (2), (b) a thermosetting resin and (c) a curing agent for the thermosetting resin, as essential components. Wherein the particle of (a) the phosphinate expressed by formula (1) or the diphosphinate expressed by formula (2) has an average particle diameter of 2-7 micrometers, and the ratio of a major axis to minor axis (major axis/minor axis) of 1-3.

Description

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

  In recent years, due to the growing awareness of environmental issues, prepregs, metal foil-clad laminates, and printed wiring boards used in electronic devices, etc. have no risk of generation of harmful gases such as dioxins during incineration such as disposal. Products that do not contain compounds are being introduced.

  In order to impart flame retardancy without containing a halogen-based compound, a method such as adding a phosphorus-based flame retardant or an inorganic filler to the resin composition is performed. As phosphorus flame retardants, phosphate esters such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, and condensed phosphate esters such as resorcinol diphosphate are widely used. When these flame retardants are used, the phosphorus content is as low as about 7 to 10% by weight, and the flame retardant must be added in a large amount in the resin composition. It had the problem that the heat resistance of a laminated board and a printed wiring board fell (refer patent document 1).

  Under such circumstances, as shown in Patent Document 2, a technique using phosphinate or diphosphinate as a flame retardant has been introduced. However, when a phosphinate or diphosphinate is used, the metal foil peeling strength and alkali resistance of the metal foil-clad laminate may be inferior depending on the particle size and shape of the particles.

JP 2003-206392 A JP 2002-284963 A

  The present invention solves the above-mentioned problems of the prior art, does not contain a halogen-based compound, has excellent flame retardancy, heat resistance, and metal foil peeling strength, and a prepreg and metal foil tension using the same. A laminated board and a printed wiring board are provided.

The present invention relates to the following.
(1) (a) a phosphinic acid salt represented by the general formula (1) or a diphosphinic acid salt represented by the general formula (2), (b) a thermosetting resin, and (c) a curing agent for the thermosetting resin. It is a resin composition as an essential component, and (a) the average particle diameter of the phosphinic acid salt represented by the general formula (1) or the diphosphinic acid salt represented by the general formula (2) is 2 to 7 μm, And the resin composition whose ratio (major axis / minor axis) of the major axis and minor axis of the particles is 1 to 3.

（一般式（１）又は一般式（２）中のＲ¹、Ｒ²は互いに同一でも異なっていてもよく、一価の直鎖状のまたは枝分かれした炭素数１〜６のアルキル基またはアリール基であり、Ｒ³は二価の直鎖状のまたは枝分かれした炭素数１〜１０のアルキレン基、又は炭素数６〜１０のアリーレン基、又はアルキルアリーレン基、又はアリールアルキレン基であり、ＭはＭｇ、Ｃａ、Ａｌ、Ｓｂ、Ｓｎ、Ｇｅ、Ｔｉ、Ｚｎ、Ｆｅ、Ｚｒ、Ｃｅ、Ｂｉ、Ｓｒ、Ｍｎ、Ｌｉ、Ｎａ、Ｋからなる群の少なくとも１種より選択される金属類であり、ｍは１〜４の整数であり、ｎは１〜４の整数であり、そしてｘは１〜４の整数である。）
（２）項（１）に記載の樹脂組成物を基材に含浸・乾燥させて得られるプリプレグ。
（３）項（２）に記載のプリプレグ、又は該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箔張積層板。
（４）項（３）に記載の金属箔張積層板に回路加工を施して得られる印刷配線板。

(R ¹ and R ² in the general formula (1) or the general formula (2) may be the same or different from each other, and are a monovalent linear or branched alkyl group or aryl group having 1 to 6 carbon atoms. R ³ is a divalent linear or branched alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an alkylarylene group, or an arylalkylene group, and M is Mg , Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, and K are metals selected from the group consisting of m, An integer from 1 to 4, n is an integer from 1 to 4, and x is an integer from 1 to 4.)
(2) A prepreg obtained by impregnating and drying a substrate with the resin composition according to item (1).
(3) A metal foil-clad laminate obtained by laminating a metal foil on one side or both sides of a prepreg according to item (2) or a laminate obtained by laminating a plurality of the prepregs, and heating and pressing.
(4) A printed wiring board obtained by subjecting the metal foil-clad laminate according to item (3) to circuit processing.

  The metal foil-clad laminate and printed wiring board obtained from the resin composition and prepreg in the present invention do not contain a halogen compound and are excellent in flame retardancy, heat resistance, and metal foil peeling strength.

Hereinafter, the present invention will be described in detail.
The resin composition of the present invention comprises (a) a phosphinic acid salt represented by the general formula (1) or a diphosphinic acid salt represented by the general formula (2), (b) a thermosetting resin, (c) the heat A curing agent for the curable resin is an essential component. In the present invention, (a) the phosphinic acid salt represented by the general formula (1) and the diphosphinic acid salt represented by the general formula (2) may be used alone or in combination. And the average particle diameter of the particle | grains of (a) phosphinate or diphosphinate used in this invention is 2-7 micrometers, Preferably the thing of 3-5 micrometers is used. When the average particle size is less than 2 μm, the metal foil peeling strength may be inferior, and when it exceeds 7 μm, the resin composition tends to settle when an organic solvent is added to the resin composition.

The ratio (major axis / minor axis) of the major axis to the minor axis of (a) phosphinate or diphosphinate particles used in the present invention is 1 to 3. When the ratio of the major axis to the minor axis (major axis / minor axis) exceeds 3, the metal foil-clad laminate metal foil peel strength and alkali resistance may be inferior. In addition, about ratio (major axis / minor axis) of a major axis and a minor axis, about the 100 particles randomly extracted from the particles observed with a scanning electron microscope, the maximum diameter and the minimum diameter measured for each particle were determined. [Long diameter / short diameter] was calculated as the long diameter and the short diameter, respectively, and the average value for 100 samples was taken as the ratio of the long diameter to the short diameter.

  The maximum particle size of the (a) phosphinate or diphosphinate particles used in the present invention is preferably 20 μm or less. When the maximum particle size exceeds 20 μm, the reliability may be poor in electrical characteristics or the like when the thickness of the metal foil-clad laminate is thin or the circuit pattern formed on the metal foil-clad laminate is fine. In addition, when (a) phosphinate or diphosphinate used in the present invention is added, various surface treatment agents may be added as necessary. The amount of (a) phosphinic acid salt or diphosphinic acid salt is not particularly limited, but the total solid content of (b) thermosetting resin and (c) curing agent in the resin composition is 100 parts by weight. The amount is preferably 5 to 40 parts by weight.

  (B) The 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, and a cyanate compound, and these are used 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 (b) a curing agent in the case of using an epoxy resin as a thermosetting resin, an amine compound, a polyfunctional phenol compound , Acid anhydride compounds, and the like, and these may be used alone or in combination of two or more. (C) 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 (b) thermosetting resin.

  Even when any (b) 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. Further, the resin composition used in the present invention may be appropriately added with a filler, a catalyst, a flexible agent, and the like as necessary.

  The varnish of the resin composition of the present invention can be obtained by adding and mixing an organic solvent to the above compounded material (resin composition) as necessary. 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 foil-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 at the time of heat and pressure molding depend on the reactivity between the thermosetting resin and the curing agent, and therefore are selected according to the resin material used, and are usually in the range of 130 to 250 ° C., preferably 150 to 200 ° C. Usually, a pressure in the range of 0.5 to 20 MPa, preferably 1 to 8 MPa, a heating and pressurizing 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 foil-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 1-2, Comparative Examples 1-3)
Table 1 shows the composition of the resin compositions of Examples 1 and 2 and Comparative Examples 1 to 3. A material having the blending amount shown in Table 1 and methyl ethyl ketone as an organic solvent were blended and stirred for 60 minutes to obtain a resin composition varnish. In addition, OP930 (brand name by Clariant Japan Co., Ltd.) phosphorus flame retardant was used as the phosphinic acid salt represented by the general formula (1). Methyl ethyl ketone was blended so that the solid content of the varnish of the resin composition was 50% by weight. The prepared resin composition varnish was impregnated into a 0.1 mm thick glass cloth (2116, trade name, manufactured by Asahi Sebel Co., Ltd.), heated and dried at 160 ° C. for 5 minutes to give a prepreg having a resin content of 50% by weight. Obtained. Four prepregs are stacked, and 18 μm thick copper foil (GTS-18: Furukawa Circuit Foil Co., Ltd., trade name) is placed on both sides of the prepreg. A copper clad laminate was produced by molding.

(Evaluation of solder heat resistance)
The 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 1 hour. It was immersed in 288 ° C. solder for 20 seconds, and the appearance was visually evaluated. The results are shown in Table 1 above. “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. Indicated.

(Evaluation of flame retardancy)
Flame retardancy was measured according to the UL94-V method. The results are shown in Table 1 above.

(Copper foil peel strength)
It measured based on JIS C 6481. The results are shown in Table 1 above.

  As is apparent from Table 1, Examples 1 and 2 of the present invention are phosphinic acid salts represented by the general formula (1) having an average particle diameter of 3.2 μm and a major axis / minor axis = 1.8 as a phosphorus flame retardant. By using, it is excellent in all of a flame retardance, solder heat resistance, and copper foil peeling strength compared with Comparative Examples 1-3. On the other hand, Comparative Example 1 uses a phosphinate having a major axis / minor axis = 7.7, so that the copper foil peel strength is inferior, and Comparative Example 2 uses a phosphinate having an average particle diameter of 1.5 μm. Since it uses, it is inferior to copper foil peeling strength, and since the comparative example 3 uses triphenyl phosphate as a phosphorus flame retardant, its flame retardance is low, and also heat resistance is inferior.

Claims (4)

(A) The phosphinic acid salt represented by the general formula (1) or the diphosphinic acid salt represented by the general formula (2), (b) a thermosetting resin, and (c) a curing agent for the thermosetting resin as an essential component. And (a) the phosphinic acid salt represented by the general formula (1) or the diphosphinic acid salt represented by the general formula (2) has an average particle diameter of 2 to 7 μm, and the particles A resin composition having a ratio of major axis to minor axis (major axis / minor axis) of 1 to 3.

(R ¹ and R ² in the general formula (1) or the general formula (2) may be the same or different from each other, and are a monovalent linear or branched alkyl group or aryl group having 1 to 6 carbon atoms. R ³ is a divalent linear or branched alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 10 carbon atoms, an alkylarylene group, or an arylalkylene group, and M is Mg , Ca, Al, Sb, Sn, Ge, Ti, Zn, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na, and K are metals selected from the group consisting of m, An integer from 1 to 4, n is an integer from 1 to 4, and x is an integer from 1 to 4.)   A prepreg obtained by impregnating and drying a substrate with the resin composition according to claim 1.   A metal foil-clad laminate obtained by laminating metal foil on one side or both sides of the prepreg according to claim 2 or a laminate obtained by laminating a plurality of the prepregs, and heating and pressing.   A printed wiring board obtained by subjecting the metal foil-clad laminate according to claim 3 to circuit processing.