JPS6198745A - Production of prepreg for printed circuit board - Google Patents

Abstract

PURPOSE:To obtain prepreg for printed circuit board having improved drill processing properties, copper foil release strength, and shelf stability, by blending an epoxy resin with a novalak resin, a curing promoter, and dicyandiamide (derivative) to give varnish, impregnating the varnish into glass nonwoven fabric, etc.,k and drying it. CONSTITUTION:(A) 100 pts. wt. epoxy resin such as brominated bisphenol A epoxy resin is blended with (B) 0.5-1.5 equivalent based on epoxy group in the component A of a novdolak resin such as phenolic novolak epoxy resin, (C) 0.01-5 pts. wt. curing promoter such as an imidazole compound whose secondary amino group is preferably masked with acrylonitrile, isocyanate, melamine acrylate, etc., and (D) 0.1-1 pt. wt. dicyandiamide or derivative obtained by adding an amine to it to give varnish, which is impregnate-d i-nto glass nonwoven fabric, which is dried at 80-200 deg.C, to give the aimed prepreg.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to epoxy glass cloth, which is a material for printed wiring boards;
The present invention relates to a method for producing an epoxy-glass nonwoven fabric prepreg.

[Conventional technology]

As the density of printed wiring boards increases, they become more flexible and the diameter of through holes becomes smaller, creating a demand for prepregs for printed wiring boards with good drillability and metal-clad laminates obtained using prepregs. 'L'''C. Among drilling processability, the occurrence of smear significantly impairs through-hole reliability by interfering with the conduction between the inner layer circuit copper and the through-hole plating copper.Printed wiring board manufacturers have to remove smear. In this case, smear removal treatment is performed, but since #-sulfuric acid, hydrofluoric acid, etc. are used, there are safety issues, and it also roughens the inner wall of the through hole, reducing reliability.The cause of smearing is friction during drilling. The resin softened by heat is attached to the cross section of the inner layer circuit copper using a drill.

Dicyandiamide, which has been conventionally used as a curing agent for epoxy glass fabric prepregs, has poor compatibility with resins and often remains unreacted.

Therefore, the cured resin material decomposes and softens at temperatures of 250° C. or higher. In order to prevent such softening of the cured product, a curing agent is required that sufficiently coexists with the epoxy resin and has good reactivity.

[Problem that the invention seeks to solve]

The present invention is an epoxy resin for printed wiring boards that aims to improve drill workability, which is a drawback of conventional epoxy resin-dicyandiamide-based systems, and copper foil peel strength and storage stability, which are drawbacks of epoxy resin-polyphenol-based systems. - A method for producing glass cloth prepreg and epoxy-glass nonwoven prepreg.

[Means for solving problems]

In the present invention, after impregnating a glass cloth or a glass nonwoven fabric with a varnish containing (at epoxy position 1 resin, (b) novolak tree L (cl hardening accelerator) and (d) dicyandiamide or fc/ri dicyandiamide derivative as essential components, This is a method for manufacturing a prepreg for a printed wiring board, which is characterized by drying the prepreg.

The present invention will be explained in detail below.

The epoxy resins in (a) include bisphenol A epoxy side fat, bisphenol p5 epoxy resin, bisphenol S epoxy resin, phenol novolac epoxy resin, cresol novolak epoxy resin, bisphenol A novolac epoxy resin, and bisphenol F novolac epoxy. resin, alicyclic epoxy resin,
There are glycidyl ester-type epoxy resins, glycidylamine-type epoxy resins, hydantoin-type epoxy resins, incyanurate-type epoxy resins, and /S halides and hydrogenated products thereof, and several types thereof can be used in combination.

It is also possible to use a mixture of these epoxy resins.

When it is necessary to make the manufactured prepreg flame retardant, halogenated epoxy resin is necessary.

Sufficient flame retardancy cannot be obtained with halogenated epoxy resin alone.
If not, it is preferable that VC contains compounds generally called flame retardants such as tetrabromobisphenol A% decabromodiphenyl ether, antimony trioxide, and tetraphenylphosphine. In order to maintain the properties of the prepreg for printed wiring boards, the amount of flame retardants other than the epoxy resin 6 should be kept to the minimum amount, and at most 100 parts by weight of the epoxy tlW. It is preferable that the amount is 60 parts by volume or less.

The novolac resin (b) may be any resin as long as it polymerizes with the epoxy position I fat, such as phenol, cresol, and alkylphenol.

Examples include novolak resins such as catechol, bisphenol A, and bis-2-enol F, and halogenated products of these novolac resins. These novolac resins are (
The irI type can also be used together. It is preferable to mix @t so that the amount of phenolic hydroxyl group is in the range of 0.5 to 1.5 equivalents to the epoxy group. If γ is outside this range, sufficient drilling depth will not be obtained and drilling workability will not improve.

The curing accelerator (C) is an imidazole compound.

Organic phosphorus compounds, tertiary amines, quaternary ammonium salts, etc. are used, but imidazole compounds whose secondary amino groups are masked with acrylonitrile, incyanate, melamine acrylate, etc. are conventionally used. 2
It is possible to obtain a prepreg with storage stability that is more than twice as stable. The imidazole compound used here is imidazole, 2-ethylimidazole, 2-ethyl-
4-Methylimidazole% 2-phenylimidazole%
2-undecylimidazole, 1-benzyl-2-methylimitasole, 2-heptadecyl imidazole, 4
, 5-diphenylimidazole, 2-methylimidacillin, 2-ethyl-4-methylimidacillin, 2-phenylimidacilline, 2-undecylimidacilline, 2-heptadecylimidacillin, 2-isopropyl Imidazole, 2,4-dimethylimidazole%2-2enyl4
-Methylimidazole.

2-ethylimidacillin, 2-isopropylimidacillin, 2,4-dimethylimidacillin, 2-phenyl-4
-Methylimidacillin, etc., and masking agents include acrylonitrile, phenylene diisocyanate, toluene diisocyanate, naphthalene diisocyanate,
Examples include hexamethylene diisocyanate, methylene and sphenyl isocyanate, and melamine acrylate.

Several types of these curing accelerators may be used in combination, and the blending amount is preferably 0.0 per 100 parts of the epoxy resin.
1 to 51 quantities. If the amount is less than 0.01 parts by weight, the effect will be small, and if it is more than 5 parts by weight, the drilling workability will be poor.

Among the dicyandiamide or dicyandiamide derivatives in (1), dicyandiamide derivatives are those obtained by adding an amine to dicyandiamide, and include dicyandiamide-aniline adduct, dicyandiamide-methylaniline adduct, dicyandiamide-diaminodiphenylmethane adduct, dicyandiamide- Examples include dichlorodiaminodiphenylmethane adducts. Several kinds of these dicyandiamides or dicyandiamide derivatives can be used in combination. The blending amount is preferably 0.1 to 1.0 parts by weight per 100 parts by weight of the epoxy resin.

If more than 1 part by weight is added, the decomposition and softening temperature of the cured resin will decrease, and the smear generation rate will increase. Mafco.

If it is less than 1 part by weight, the copper foil peel strength will decrease.

Solvents used in varnish production include acetone, methyl ethyl ketone, toluene, xylene, methyl imbutyl ketone, ethyl acetate, ethylene glycol monomethyl ether, N,N-dimethylformamide, N,N-dimethylacetamide, methanol, and ethanol. You can also use a mixture of several types of these.

Moreover, the above (a), (b), (C), and (d) are essential components, and it is also possible to mix other compounds.

After impregnating the varnish obtained by blending the above (aJ, (b) (C), (dl) into a glass cloth or glass nonwoven fabric, it is dried in a drying oven at a temperature of 80 to 200°C to form a prepreg for printed wiring boards. The prepreg is heated and pressed to produce printed wiring boards or metal 5iX laminates.

〔Example〕 Examples of the present invention will be described below.

Example 1 Araldite 8011 (brominated bisphenol A type epoxy resin) 7ON parts (product name Nippon Ciba Geigy) Ep-154 (phenol novolac type epoxy resin) 30 parts (product name:
Oil-based shell epoxy) HP-607 (phenol novolac resin) 3ON Kabe (product name:
Hitachi Chemical) Dicyandiamide 0.3 parts by weight GX-8
009H (incyanate mask imidazole) 0.5 parts by weight (product name: Daiichi Kogyo!!!Yaku) Methyl ethyl ketone 6 parts by weight A 1 mm thick glass cloth was impregnated with the varnish made of the above composition and heated at 150°C for 10 minutes. A prepreg was obtained by drying for a minute.

Example 2 DX-1 instead of dicyandiamide in Example 1
A prepreg was obtained in the same manner as in Example 1 by blending 1 part by weight of 47 (dicyandiamide-methylaniline adduct, trade name Niziel Chemical).

Example 3 KLX-1 instead of dicyandiamide in Example 1
006F (dicyandiamide difuminodi-2-enylmethane addition nose, part name: Dai-Kogyo Seiyaku) was installed in 0.5 parts, and VCG
, Z-CN (?squimidazole, product name: Shin-Etsu Chemical) Y17 parts by weight were blended, and a Flipreg was obtained in the same manner as in Example 1.

Comparative Example 1 Araldite 8011 70 parts by weight Ep-15
430 g HP-60730# 2E4MZ<imidazole) 0.2 # (Part name: Shikoku Kasei) Methyl ethyl ketone 60 l A prepreg was obtained in the same manner as in Example 1 using a varnish made of the above blend.

Comparative Example 2 Araldite 8011 70 Sadadobu Ep-15
430# Dicyandiamide 312E4MZ
0.2 #Methyl ethyl ketone
203! jitt part methyl cellosolve
40 l Varnish made of the above formulation Q, i
mm1! i! , impregnated into glass cloth and heated at 160℃ for 10
A prepreg was obtained by drying for a minute.

Prepreg 15 obtained in Examples 1 to 6 and Comparative Examples 1 and 2 above
A 6-layer printed distribution board was fabricated by heat-pressing molding at 170°C for 60 minutes using six sheets of 35μ copper foil, and the drill workability and copper foil peelability were evaluated.

Conducted tests on solder heat resistance and prepreg storage stability.
Ta. Drilling conditions are rotation speed 60 krpm feed rate 1
0m/min, hole diameter 1. Qmm, the number of bundled sheets is 12,
Holes were drilled to 000 bits and the smear occurrence rate was measured.

Characteristic test results are shown in Table NC.

Table 1 Characteristic test results Note 1) Average value of the smear occupancy rate of the cross-section of the copper layer inside the through-hole for 20 holes.

Note 2) 35t1 single-sided phased copper foil, 10flIITl width.

Note 5) When copper oxide treatment is applied to the glossy surface of copper foil.

As shown in Table 1, in Examples 1 to 6 and Comparative Example 1, the smear occurrence rate was lower and better than in Comparative Example 2, which did not use the polyphenol.

It can be seen that, compared to Comparative Example 1, Examples 1 to 3 have a value that does not cause any problem in terms of copper foil peeling strength.

Furthermore, compared to Comparative Example 1, the storage stability of Flipreg was significantly improved in Examples 1 to 3 in which mask imidazole was used.

〔effect〕

The printed wiring board prepreg of the present invention has excellent drill workability, copper foil peeling strength, and storage stability.

This is a significant improvement over conventional technology.

<1. Two, \--5r

Claims (1)

[Claims] 1. After impregnating a glass cloth or glass nonwoven fabric with a varnish containing as essential components (a) an epoxy resin, (b) a novolac resin, (c) a curing accelerator, and (d) dicyandiamide or a dicyandiamide derivative. A method for producing prepreg for printed wiring boards, which comprises drying the prepreg. 2. The method for manufacturing a prepreg for a printed wiring board according to claim 1, wherein the curing accelerator is an imidazole compound with masked imino groups. 3. The amount of dicyandiamide or dicyandiamide derivative is 0.1 to 1 per 100 parts by weight of the epoxy resin.
The method for manufacturing a prepreg for a printed wiring board according to claim 1 or 2, characterized in that the amount is parts by weight.