JPH06112608A - Glass cloth for glass-epoxy printed wiring board - Google Patents

Abstract

PURPOSE:To readily acquire prepreg of good defoaming property at a low cost regardless of a kind of silane coupling agent by treating glass cloth by using ammonium chloride in addition to the silane coupling agent. CONSTITUTION:A first, 0.5wt.% water solution of N-BETA-(aminoethyl)-gamma- aminopropyl trimethoxysilane hydrochloride is prepared, and 0.2wt.% of ammonium chloride and acetic acid are added thereto to make PH 4.0. Glass cloth WEA 18W105 is immersed in the treatment liquid, squeezed by a mangle to realize treatment liquid keeping ratio of about 30% to glass cloth, and dried for 5 min at 110 deg.C. Then, resin varnish is prepared according to NEMA standard FR-4 prescription. The glass cloth is impregnated with the prepared varnish, and dried at 130 deg.C for 7 minutes to form a prepreg. Eight sheets of the prepreg are laminated, copper foil is further laminated up and down thereof and they are heated and molded at a pressure of 30kg/cm<2> at 170 deg.C for 90min to form a copper clad laminated board. Copper foil is removed from the laminated board by etching.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass cloth used as a substrate for a printed wiring board, and more particularly to a glass cloth.
The present invention relates to a glass cloth used as a base material for an epoxy printed wiring board.

[0002]

2. Description of the Related Art In the process of molding a printed wiring board, a glass cloth takes the form of a temporary prepreg, and this prepreg contains many voids. Most of these voids are removed during the subsequent press molding, but some voids remain and problems such as solder heat resistance and insulation resistance decrease occur. As a method for solving this problem, a silane coupling agent in which benzyl chloride is added to N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane having slow curing property and good defoaming property is used. (Japanese Patent Laid-Open No. 2-305749)

[0003]

In order to eliminate voids remaining inside the printed wiring board, benzyl chloride is added to N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane as a silane coupling agent having a good defoaming property. A silane coupling agent added with is used. However, in this method, the silane coupling agent that can be used is limited, and the general characteristics of the printed wiring board are influenced by the performance of the silane coupling agent itself. An object of the present invention is to develop a glass cloth capable of easily and inexpensively obtaining a prepreg having good defoaming property regardless of the type of silane coupling agent.

[0004]

SUMMARY OF THE INVENTION The present invention is intended to solve the above problems by treating glass cloth with ammonium chloride in addition to the silane coupling agent. Examples of the silane coupling agent used in the present invention include N-β- (aminoethyl) mentioned above.
-Γ-aminopropyltrimethoxysilane, its hydrochloride, epoxysilane, etc. can be used alone or in combination. The concentration of the silane coupling agent is preferably in the range of 0.05 to 1.0%. The concentration of ammonium chloride is preferably in the range of 0.01 to 0.5% by weight. The glass cloth of the present invention is used after being deoiled by heating to remove the sizing agent. The silane coupling agent and ammonium chloride are deposited on the glass cloth from which the sizing agent has been removed by treatment.

[0005]

[Function] Ammonium chloride has a function of delaying the polymerization reaction of the epoxy groups because it reacts with the epoxy group. Therefore, the glass cloth treated with ammonium chloride makes it possible to obtain a prepreg having good defoaming property by making the epoxy resin used as the matrix resin slow-curing. That is, in the laminating step in which the prepregs are laminated and heated and pressed, the curing reaction speed of the epoxy resin is reduced, so that the viscosity increase rate of the resin is small, and therefore the defoamable time in the laminated prepreg is increased accordingly. As a result, the number of voids contained in the obtained laminate is small.

[0006]

EXAMPLE A 0.5% by weight aqueous solution of N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride was prepared, and 0.2% by weight of ammonium chloride and acetic acid were added thereto to adjust the pH to 4 It was set to 0.0. (Treatment liquid) A glass cloth WEA18W105 (manufactured by Nitto Boseki Co., Ltd.) is dipped in this treatment liquid, and then squeezed with a mangle so that the treatment liquid retention rate is about 30% with respect to the glass cloth. Dried. Next, a resin varnish was prepared according to the NEMA standard FR-4 formulation. Epicoat 5046-B-8 [made by Yuka Shell Epoxy Co., Ltd.] 100 parts Epicoat 154 [made by Yuka Shell Epoxy Co., Ltd.] 20 parts Dicyandiamide 4 parts 2-Ethyl-4-methylimidazole 0.2 Part Methyl ethyl ketone ... 15 parts This prepared varnish was impregnated with glass cloth and dried at 130 ° C. for 7 minutes to obtain a prepreg. Eight pieces of this prepreg were stacked, copper foils were stacked on top and bottom, and heat-molded at a pressure of 30 kg / cm ² at 170 ° C. for 90 minutes to obtain a copper-clad laminate. The copper foil was removed from this laminated plate by etching to obtain a test piece.

Comparative Example A test piece of Comparative Example was prepared in the same manner as in Example except that ammonium chloride was omitted from the composition of the treatment liquid of Example. For the laminated plate test pieces obtained in Examples and Comparative Examples, the presence or absence of voids was visually determined and shown in Table 1. Further, the gelling time was measured for the epoxy prepregs of Examples and Comparative Examples and shown as a guide for the curing rate of each prepreg.

[0008]

[Table 1] Defoaming is good for ◯ and somewhat bad for △ Gel time measured at 160 ℃

[0009]

According to the present invention, a glass cloth having a good defoaming property can be obtained when the epoxy prepreg is used without being limited to the kind of the silane coupling agent.

Claims (1)

[Claims] 1. A glass cloth for a glass-epoxy printed wiring board, which is treated with a silane coupling agent and ammonium chloride.