JPS6131243A - Manufacture of epoxy resin laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a glass epoxy laminate for printed wiring boards that has small surface irregularities and excellent drill workability.

(Conventional methods and their problems) Since the goal of electronic devices is to achieve miniaturization, high reliability, and low cost through high-density wiring, the printed wiring boards used in these devices must also meet these demands. Improvements and developments are underway.In particular, concerns include reducing surface irregularities (smoothing), improving drilling workability (especially when drilling small holes), and improving thermal conductivity.

Conventionally, a method known to reduce surface irregularities is to increase the amount of resin impregnated into the prepreg, but this method tends to cause a lot of resin to flow during lamination molding, and the prepreg tends to shift, making it impractical in practice. was problematic. Also, regarding the drilling workability of small holes, the thickness is 1.6
When drilling a 0.3fiφ hole in Tsuru's glass epoxy laminate, it is possible to drill just one sheet depending on the selection of drilling conditions, but it is difficult to drill even one sheet under normal conditions, and it is generally difficult to improve productivity. There was a problem in the three-ply stacking method used to raise the drill, which caused problems such as the drill breaking.

[Means for solving problems]

As a result of intensive studies to solve the above problems, the present inventors have found that by using a prepreg containing a specific inorganic filler in a specific range, the surface unevenness is small and the drillability is excellent. They also discovered that a glass capoxy laminate could be obtained and completed the present invention.

That is, the present invention is an epoxy resin having two or more epoxy groups in the molecule, which contains P-alkylphenol as a main component, has an average degree of polymerization of 3 to 6, and has a free phenol content of 0.5.
Calcium silicate 80 to 99 wt%,
Inorganic filler consisting of 1 to 20 wt% white carbon (
(A) 35-45wt, which is obtained by impregnating or applying a varnish containing B) to a glass woven fabric (C) and drying it.
%, said (B) 15-2 δwt%, said (C) 35-4
Layer one or more B-stage yellowtail preg with a composition ratio of 5 wt%, as necessary.

This is a method for manufacturing an epoxy resin laminate for printed wiring boards, which is characterized by stacking metal foil on one or both sides and laminating it.

The configuration of the present invention will be explained below.

As the epoxy resin of the epoxy resin composition (^) of the present invention, there is no particular limitation and any one that has been conventionally used for laminated boards can be used. Specifically, bisphenol A type epoxy resin can be used. Epoxy resin, bisphenol F epoxy resin, phenol novolank epoxy resin, Talesol novolank epoxy resin, halogenated bisphenol A epoxy resin, halogenated phenol novolak epoxy resin, polyglycol epoxy resin, alicyclic epoxy These resins are used alone or as a mixture of two or more. In addition, as mentioned above, a curing agent is one that contains P-alkylphenol as a main component, usually contains 50% or more of P-alkylphenol, has an average degree of polymerization of 3 to 6, and has free phenols of 0.5wt% or less. It is a certain novolak resin, and examples of P-alkylphenol include P-cresol and P-nonylphenol. It is estimated that the use of phenols having an alkyl group at the P-position has the effect of preventing the phenols from forming a quinone structure and discoloring upon heating. This is not preferable because it deteriorates the compatibility with the epoxy resin and also impregnates the glass woven fabric base material. In addition, free phenols not only cause poor heat resistance, but also worsen discoloration when heated.
Exceeding 0.5-% is not preferred. The imidazoles used as a curing accelerator include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole,
2-phenylimidazole, 1-benzyl-2-methylimidazole, etc., and modified products of these imidazoles with acrylonitrile, trimellitic acid, dicyandiamide, etc. are exemplified, and these can be used alone or in combination of two or more. Used as appropriate, the amount used is 0.0
It is used in a range of 1 to 5 wt%, preferably 0.05 to 1 wt%.

The calcium silicate of the inorganic filler (B) of the present invention is C
It is a substance represented by the chemical formula of a5t's, and examples of commercially available products include wollastonite (Nagase Sangyo Hat), Kemolit (Maruwa Biochemical System, etc.).White carbon also refers to vapor-phase anhydrous silica. , hydrated fine powder silicic acid and calcium silicate, which are generally used as thixotropic agents and reinforcing agents for plastics, thixotropic agents for paints, etc.The silicic acid in the inorganic filler (B) The usage ratio of calcium acid and white carbon is 80 to 99 for the former.
wt% and the latter ranges from 1 to 20 wt%. If the amount of white carbon used is less than 1 wt%, misalignment will easily occur during lamination molding, making it difficult to obtain a good laminate, and if it exceeds 20 wt%. This is not preferable because the impregnating properties of the forceless woven fabric become insufficient.

The glass woven fabric (C) of the present invention is JIS I? 3
416, and generally, alkali-free, silane coupling treated glass cloth is used.

The prepreg of the present invention is prepared using the above components.

A composition of an epoxy resin composition and an inorganic filler is
The epoxy resin composition (A) 35~
45 tons%, inorganic filler (B) 15-25wt%,
Glass woven fabric (C) B-s with a composition ratio of 35 to 45 wt%
A varnish with a composition that will yield a prepreg of 100% of the total weight is prepared by sufficiently mixing with a conventional mixing means, impregnated or applied onto a glass woven fabric, and dried to obtain the prepreg of the present invention.

If the inorganic filler (B) in the prepreg is less than 15 wt%, the prepreg tends to shift during lamination molding, and 25
If it exceeds wt%, drill workability tends to decrease, which is not preferable. Further, if the glass woven fabric (C) is less than 35 wt%, the mechanical properties will be insufficient, and if it exceeds 45 wt%, drill workability tends to deteriorate, which is not preferable. Further, if the content of the epoxy resin composition (^) is less than 35 wt%, lamination molding becomes difficult, and if it exceeds 45 wt%, misalignment tends to occur during lamination molding, which is not preferable.

One or more sheets of prepreg obtained by the above manufacturing method are used, and if desired, metal foil (especially electrolytic copper foil, etc.) is layered and sandwiched between mirror plates under normal lamination molding conditions, temperature 100-200℃, pressure. 5-100 kg/cA,
- The laminate of the present invention is manufactured by lamination molding for 0.5 to 5 hours.

〔Example〕

Hereinafter, a more specific explanation will be given by showing examples and comparative examples. In addition, "%" in Examples and Comparative Examples means "weight" unless otherwise specified.

Example-1 Bisphenol A type epoxy resin (trade name: Epicote 1001, manufactured by Yuka Shell Epoxy ■, epoxy equivalent: 4
50-500) 62%, P-alkylphenol novolac resin (trade name: Praiohen LF5111,
Manufactured by Dainippon Ink ■, hydroxyl equivalent: 115-120) 10.
8% and 0.2% of 2-ethyl-4-methylimidazole were dissolved in acetone and mixed.

In addition, calcium silicate (trade name: Wollastonite') 24.3%, vapor phase silica type white carbon (trade name: Aerosil, manufactured by Nippon Aerosil ■) 2.7%
% and mixed thoroughly, acetone was added to prepare an inorganic-filled varnish.

This varnish was impregnated into a glass woven fabric with a thickness of 0.18+n, dried at 130°C, and a B-stage glass woven fabric 4 was obtained.
4%, epoxy resin composition 40.9%, inorganic filler 15
．． A 1% prepreg was obtained.

Six sheets of this prepreg were stacked, 18 mm thick copper foil was layered on both sides, and lamination molding was carried out at a temperature of 170° C. and a pressure of 20 kg/cd for 2 hours to obtain a double-sided copper-clad laminate with a thickness of 1.5 am. The properties of this laminate are shown in Table 1.

Example-2 Brominated bisphenol A type epoxy resin (trade name: Epicote 1045, manufactured by Yuka Shell Epoxy ■, epoxy equivalent: 450-500) 56%, P-alkylphenol novolak resin (trade name: Plyauchen LF 5)
111, manufactured by Dainippon Ink ■, hydroxyl equivalent 115-120
) 13.5% and 0.5% of an acrylonitrile modified product of 2-undecylimidazole were dissolved and mixed in methyl cellosolve.

To this solution, 24.6% calcium silicate (trade name: Kemori 7to) and wet process white carbon (trade name;
After adding 5.4% of Nipsil (manufactured by Nippon Silica ■) and thoroughly mixing, acetone was added to prepare an inorganic-filled varnish.

A glass woven fabric with a thickness of 0.18 tm was impregnated with this varnish and dried at 140°C to form a B-stage glass woven fabric 4.
1%, epoxy resin composition 41.3%, inorganic filler 17
．． A 7% prepreg was obtained.

Layer 6 sheets of this ρ prepreg, layer 18 layers of copper foil on both sides, and heat 1.5 at a temperature of 180℃ and a pressure of 50kg/cJ.
A double-sided copper-clad laminate having a thickness of 1.6 fi was obtained by time lamination molding.

The properties of this laminate are shown in Table 1.

Example-3 Bisphenol A type epoxy resin (product name: Kobikoat 1001, manufactured by Yuka Shell Epoxy ■) 40%, phenol novolac type epoxy resin (product name: Epicoat 15)
4. Made of Yuka shell epoxy ■, epoxy equivalent 176-1
81) 5% P-alkylphenol novolac resin (
Product name: Praiohen LF 5111) 14.5%
, 2-phenylimidazole modified with trimellitic acid 0
．． 5% was dissolved and mixed in N,N-dimethylformamide.

This solution contains 38% calcium silicate (trade name: wollastonite), calcium silicate white carbon (
2% (trade name: Fluorite, manufactured by Tokuyama Soda ■) was added and thoroughly mixed to prepare an inorganic-filled varnish.

A glass woven fabric with a thickness of 0.18 nm was impregnated with this varnish,
B-stage glass woven fabric 38 by drying at 120°C
%, epoxy resin composition 37.2%, inorganic filler 24.
An 8% prepreg was obtained.

Three sheets of this prepreg are stacked, and one side has a thickness of 35 Inn.
The copper foils were stacked and laminated for 1 hour at a temperature of 150° C. and a pressure cuff of 0 kg/cat to obtain a single-sided copper-clad laminate with a thickness of 0.8 mm. The properties of this laminate are shown in Table 1.

Comparative example-1 In Example-1, inorganic light was used as the impregnating varnish.

A prepreg made of 60% glass woven fabric was obtained using a varnish made in the same manner except that no base was used.

A double-sided copper-clad laminate was obtained in the same manner except that eight sheets of this prepreg were used. The properties of this laminate are shown in Table 1.

Comparative Example 2 A prepreg was obtained in the same manner as in Example 2 except that the white carbon in the inorganic filler was not used as the impregnating varnish, and laminated molding was carried out in the same manner as in Example 1 except that this prepreg was used.

A good laminate could not be obtained because the prepreg shifted during lamination molding.

Comparative Example 3 The same procedure as Example 3UN-2 was carried out except that a normal phenol novolak resin (hydroxyl equivalent: 105 to 11) was used instead of the P-alkylphenol novolak resin.

The properties of the obtained laminate are shown in Table 1.

Table 1 [Operations and Effects of the Invention] As is clear from the detailed description, examples, and comparative examples, the laminate manufactured by the method of manufacturing the laminate of the present invention as described above has virtually no defects due to lamination molding. It is excellent in terms of surface roughness and processability, and can be very suitably put to practical use as a substrate for printed wiring boards, which is also excellent in economical efficiency.

Claims (1)

[Claims] Epoxy resin having two or more epoxy groups in the molecule,
The main component is P-alkylphenol, and the average degree of polymerization is 3.
~6. To an epoxy resin composition (A) containing a novolac resin containing 0.5 wt% or less of free phenols and imidazole as a curing accelerator as an essential component, 80 to 99 wt% of calcium silicate and 1 to 10% of white carbon are added.
Glass woven fabric (C) is impregnated or coated with a varnish containing 20 wt% of inorganic filler (B) and dried, wherein (A) is 35 to 45 wt% and (B) is 15 to 25 wt%.
wt%, B-st with a composition ratio of 35 to 45 wt% of the (C)
A method for producing an epoxy resin laminate for a printed wiring board, which comprises stacking one or more prepregs of the same age and stacking metal foil on one or both sides of the prepreg as required.