JPS6315830A - Production of copper-clad laminate - Google Patents

Abstract

PURPOSE:To produce a copper-clad laminate excellent in adhesion of copper foil and heat resistance, by laminating a prepreg sheet formed by impregnating a sheet base with a specified resin composition with a copper foil and heating the assemblage under a pressure. CONSTITUTION:A resin composition is obtained by mixing 100pts.wt. polybutadiene epoxy resin obtained by reacting 1 equivalent of the terminal carboxyl groups of a terminal carboxyl group-modified polybutadiene containing at least 50% 1,2-polybutadiene units having double bonds in side chains in the polymer chain with 1.2-1.5 equivalent of an epoxy compound having at least two epoxy group in the molecule at 80-200 deg.C with 10-100pts.wt. maleimide compound of the formula (wherein n is 0-5 on the average), an epoxy curing agent and a polymerization catalyst. A prepreg sheet obtained by impregnating a sheet base with said resin composition and preheating it to 80-180 deg.C for 5-60min is laminated with a copper foil and the obtained assemblage is heated under a pressure.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for manufacturing a copper-clad laminate, and more specifically, it is useful as a multilayer printed wiring board with excellent copper foil adhesion and high heat resistance. The present invention relates to a method of manufacturing a copper-clad laminate.

[Conventional technology]

Conventionally, glass epoxy laminates have been commonly used as printed wiring boards for electronic devices, but as packaging density increases and wiring patterns become denser, increased heat generation has become a major problem, and recently Improving the heat resistance of substrates has become an extremely important issue. Heat-resistant toilet oils that can replace conventional epoxy resins include heat-resistant epoxy resins, polyimides, polyamideimides, silicones, etc., but none of them are necessarily satisfactory in terms of electrical properties, particularly dielectric constant. Recently, there has been increasing interest in 1,2-polybutadiene, which has double bonds in its side chains, as a low dielectric constant material without sacrificing heat resistance (for example, JP-A No. 54-7
No. 4884).

[Problem that the invention seeks to solve]

However, 1,2-polybutadiene has the disadvantage of poor adhesion to metals, etc. Therefore, the use of various modified 1,2-polybutadienes has been proposed and various studies have been conducted. However, the current situation is that there is still nothing to be satisfied with.

The present invention is intended to solve the problems mentioned in section 2 above, and provides a method for manufacturing a copper-clad laminate that has excellent heat resistance and adhesion to copper foil without impairing the original excellent characteristics of the substrate. The purpose is to provide.

[Means for solving problems]

The method for producing a copper-clad laminate of the present invention involves adding 5 1,2-polybutadiene units having double bonds in the side chains to the polymer chain □.
For each terminal carboxyl group of the terminal carboxyl group-modified polybutadiene containing 0% or more, an epoxy compound having at least 2 or more tJ epoxy groups per 1-molecule in the range of 1.2 to 15 epoxy groups. A resin composition in which a maleimide compound represented by the following formula (1), an epoxy curing agent, and a polymerization catalyst are blended as heat-resistant components into a polybutadiene epoxy resin obtained by subjecting the composition blended in advance to anti-J, b. In this method, a prepreg sheet is obtained after impregnating a sheet-like base material, and the prepreg sheets 1 to 1 are laminated together with copper foil, heated, and compressed.

(However, n is an average number and represents 0 to 5.) The terminal carboxyl group-modified bo-3-liptadiene used in the present invention has a 1,2-polybutadiene unit having a double bond in the side chain in the polymer chain. 50% or more, and has carboxyl groups at both ends, for example, Nl
5SO-PB, C-1000 (trademark, Nippon Soda Co., Ltd.)
made, number average molecular weight: 1350±150)1. l5R-
Examples include RB-810 (trademark, manufactured by EI Honsei Rubber Co., Ltd., number average molecular weight 120,000).

The epoxy compound used in the present invention may have at least two or more epoxy groups in one molecule, such as bisphenol A type Epicote 828.
(trademark, made by Shell), DER-332 (trademark, made by Dow), Gv-255 (trademark, made by Ciba), Novolac type DEN-4,31, (trademark, made by Dow), alicyclic General-purpose epoxy resins such as type CY-179 (trademark, manufactured by Ciba), as well as tetrabromobisphenol A and dibromobisphenol A types DER-542
, DER-511, (all trademarks, manufactured by Dow), Epicote 1045, Epicote 1046, Epicote 10
50 (all trademarks, manufactured by Shell), Araldite 80
47, Araldite 1. , T-8052 (both trademarks, manufactured by Ciba Corporation) and other flame-retardant epoxy resins. These epoxy resins may be used alone or in combination if necessary.

In the present invention, the blending ratio of the terminal carboxyl group-modified polybutadiene and the epoxy compound is in the range of 1.2 to 15 equivalents of the epoxy group per 1 equivalent of the terminal carboxyl group.

If the amount is less than 1.2 equivalents, the effect of improving copper foil adhesion will not appear,
If it exceeds 15 degrees, the effect of flexibility caused by polybutadiene will be weakened, which is not preferable.

The composition containing the above-mentioned terminal carboxyl group-modified polybutadiene and epoxy compound was heated to 80 to 200°C in advance.
The reaction is carried out without a catalyst or in the presence of a catalyst to produce a polybutadiene epoxy resin.

In the present invention, the polybutadiene epoxy resin thus obtained is blended with a maleimide compound represented by the above formula (1) as a heat-resistant component, diluted with an appropriate solvent, and further added with an epoxy curing agent, an epoxy polymerization catalyst, and a vinyl polymerization initiator. Add catalysts and other ingredients to make an impregnating face.

The maleimide compound used in the present invention is a compound represented by the above formula (1'), and its blending amount is in the range of 10 to 100 parts by weight based on 100 parts by weight of the above polybutadiene epoxy resin. If it is less than 10 parts by weight, the effect of high heat resistance will not be achieved, and if it exceeds 100 parts by weight, the crosslinking density will increase too much, resulting in the occurrence of cracks, etc., which are both undesirable.

Examples of the solvent include ethylene glycol monomethyl ether, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. Examples of epoxy curing agents include dicyandiamide, modified dicyandiamide, boron trifluoride, amine complex salts, and phenol resins. Examples of poxy polymerization catalysts include tertiary amines such as benzyldimethylamine, 2-(dimethylaminomethyl)phenol, and 2-neethyl-4-
Examples include imidazoles such as methylimidazole and 1-benzyl-2-methylimidazole. Examples of vinyl polymerization initiation catalysts include dicumyl peroxide, t-
Examples include organic peroxides such as butyl perbenzoate, t-butyl peroxylaurylate, and benzoyl peroxide. Maleimide compounds can be cured without the addition of catalysts, but in order to increase the curing rate, it is preferable to add the above-mentioned tertiary amici compounds, imidazoles, etc.

In the present invention, a sheet-like base material is impregnated with the impregnating varnish that has been subjected to the t:t treatment in this manner, and is pre-dried at 80 to 180°C for 5 to 60 minutes to obtain a non-tacky prepreg sheet.

At this time, it is necessary to select conditions such as drying time and temperature depending on the type and addition of the solvent, various catalysts, curing agents, etc. used.

As the sheet-like base material, for example, glass cloth, glass nonwoven fabric, glass paper, synthetic fiber nonwoven fabric, etc. can be used.

Layer several prepreg sheets obtained in this way as necessary, and layer copper foil on one or both sides.
A copper-clad laminate is obtained by laminating and molding this at a predetermined humidity and pressure.

The copper-clad laminate thus obtained has excellent heat resistance and electrical properties, and its adhesion to copper foil is highly improved compared to conventional ones, making it suitable for use in multilayer printed wiring boards. Useful.

[For production]

In the present invention, by using a polybutadiene epoxy resin in which a polybutadiene modified with a carboxylic group at one end and an epoxy compound having at least two or more epoxy groups per molecule are reacted in advance, flexibility is created in the cured network. A polyptadiene epoxy network with excellent properties and adhesive strength can be formed, and by incorporating a maleimide compound,
An imide ring useful as a heat-resistant skeleton can be formed, thereby making it possible to obtain a cured product in which a polybutadiene network and a stable imide ring structure coexist in a well-balanced manner in the cured network. In this way, a copper-clad laminate with improved heat resistance and highly improved adhesion with copper foil can be obtained without compromising the original electrical properties or other excellent properties of the substrate. It will be done.

[Example]-4 Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

81 Example 1 Liquid polybutadiene Nl5S with number average molecular reduction of 1300
6-PR, C-1000 (trademark, manufactured by Ippon Soda Co., Ltd.)
Epoxy resin Dt with 55.6 g and molecular weight of about 360!
44.4 g of R-332 (trademark, manufactured by Dow Corporation) was blended and 0.2 g of benzylmethylammonium bromide was added as a catalyst, and the mixture was reacted at 160°C for 5 hours to form a heptapolybutadiene epoxy resin. I got ゛. ° After diluting this by adding 60 g of N,N-dimethylformamide and 50 g of ethylene glycol monomethyl ether, the maleimide compound of formula (1) (where n is 0) 2
Additionally, 3 g of dicyandiamide was added as an epoxy curing agent; 2.5 g of dicumyl peroxide was added as a vinyl polymerization initiation catalyst; and 1-
A glass cloth (thickness: 0.2 mm) was impregnated with a uniformly mixed varnish obtained by blending 0.3 g of benzyl-2-methylimidazole, and dried at 140° C. for 15 minutes to obtain a prepreg sheet. Layer 8 sheets of this prepreg,
Copper M (thickness: 35 μm) was placed above and below it, and heated at 170°C.
A copper-clad laminate was obtained by press molding at 40 kg/cm2 for 90 minutes. The copper foil peeling strength of the obtained copper-clad laminate is J
Normal condition, 300°C, 12 according to IS-C-6481
Measurements were made after 0 seconds and after soldering at 300°C for 300 seconds. Heat resistance was also evaluated by measuring the thermal decomposition onset temperature.

Example 2 Polybutadiene component Nl5SO-PB, C-1
000 (mentioned above) 20.8g, Epikote 828 (trademark, manufactured by Shell Co., Ltd.) with a molecular weight of approximately 370 as an epoxy component
11.4 g, and 67.8 g of a flame-retardant epoxy resin Epicoat 1050 (trademark, manufactured by Shell Co., Ltd., bromine content 44-48%) with a molecular weight of about 880 (equivalence ratio 1 near).
0.2 g of benzyltrimethylammonium bromide was added as a catalyst, and the mixture was reacted at 160° C. for 5 hours to obtain a polybutadiene epoxy resin. After diluting this by adding 75 g of N,N-dimethylformamide and 75 g of ethylene glycol monomethyl ether, 50 g of the maleimide compound of formula (1) (where n is 0.5) was added, and trifluoride was added as an epoxy curing agent. Glass cloth (0.2 mm thick) is impregnated with a homogeneous blended varnish obtained by blending 2.5 g of boron monoethylamine complex salt, 5 g of benzoyl peroxide as a vinyl polymerization initiation catalyst, and 0.2 g of benzyl dimethylamine as an epoxy polymerization catalyst. Then, it was dried at 140° C. for 15 minutes to obtain a prepreg sheet with no tackiness. A copper-clad laminate was formed in the same manner as in Example 1, and its copper foil peel strength was measured.

The thermal decomposition start temperature was also measured in the same manner as in Example 1.

Example 3 NTSSO-PR, C-1, as a polybutadiene component
000 (mentioned above) 13.6g, molecular weight approximately 350 (7) as an epoxy component GV-255 (trademark, manufactured by Ciba Corporation) 1
7.7 g, and flame retardant epoxy resin Araldite with a molecular weight of about 680 1. , T-8052 (trademark, manufactured by Ciba Corporation,
Bromine content: 40%) 68.7g was added at an equivalent ratio of 1.
:15), and was reacted at 160° C. for 5 hours without a catalyst to obtain a polybutadiene epoxy resin. After diluting this by adding 14,100 g of N,N-dimethylformamide and 100 g of ethylene glycol monomethyl ether, a maleimide compound of the formula (where n is 0.8) 100
Furthermore, 50 g of phenolic resin PZ-6000 (trademark, manufactured by Hitachi Chemical Co., Ltd.) was added as an epoxy curing agent, 1 g of t-butyl perbenzoate 4J was added as a vinyl polymerization initiation catalyst, and 2-(dimethyl aminomethyl) phenol 0.
3 g was blended to obtain a uniformly blended varnish. A glass nonwoven fabric (thickness 0.2 mm) was impregnated with this uniformly mixed varnish, and
Drying was performed at 0° C. for 15 minutes to obtain a non-tacky prepreg sheet. A copper-clad laminate was formed in the same manner as in Example 1, and its copper foil peel strength was measured.

The thermal decomposition start temperature was also measured in the same manner as in Example 1.

Example 4 In Example 1, n as the maleimide compound of formula (I)
A prepreg sheet having a value of 2.5 was used to obtain a prepreg sheet in the same manner. This prepreg sheet was molded into a copper-clad laminate in the same manner as in Example 1, and its copper foil peel strength was measured. The thermal decomposition start temperature was also measured in the same manner as in Example 1.

Example 5 In Example 2, n as the maleimide compound of formula ())
A prepreg sheet having a value of 4.8 was used to obtain a prepreg sheet in the same manner. This prepreg sheet was molded into a copper-clad laminate in the same manner as in Example 1, and its copper foil peel strength was measured. The thermal decomposition start temperature was also measured in the same manner as in Example 1.

Comparative Example 1 JSR-RB-810 (trademark, Japan Synthetic Rubber Co., Ltd. lil, molecule Jt120000) as a polybutadiene component
100g of ethylene glycol monomethyl ether
00 g, and 5 g of dicumyl peroxide was added as a vinyl polymerization initiation catalyst to obtain a uniformly blended varnish. Thereafter, after obtaining prepregsy 1~ in the same manner as in Example 1,
When examining the copper foil peel strength and thermal decomposition onset temperature, the copper foil peel strength was very poor because polybutadiene was used alone without adding an epoxy component.

Heat resistance was also measured, but it showed a low value due to the absence of an imide skeleton.

The above results are summarized in Table 1.

Table 1 From the above results, it can be seen that the copper-clad laminate manufactured according to the present invention has excellent copper foil adhesion and high heat resistance.

〔Effect of the invention〕

According to the present invention, since a specific polybutadiene epoxy resin and maleimide compound are used, a copper-clad laminate with excellent copper foil adhesion and heat resistance can be manufactured without impairing the original characteristics of the substrate. .

Claims (2)

[Claims] (1) At least two or more epoxy groups per molecule per equivalent of terminal carboxyl group of terminal carboxyl group-modified polybutadiene containing 50% or more of 1,2-polybutadiene units having double bonds in side chains in the polymer chain. The following formula ( I
) is characterized by impregnating a sheet-like base material with a resin composition containing a maleimide compound, an epoxy curing agent, and a polymerization catalyst, forming a prepreg sheet, and laminating, heating, and compressing this prepreg sheet with copper foil. Method for manufacturing copper-clad laminates. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, n is the average number and represents 0 to 5) (2) The method for producing a copper-clad laminate according to claim 1, characterized in that 10 to 100 parts by weight of a maleimide compound is blended with 100 parts by weight of the polybutadiene epoxy resin.