JPH02308596A - Epoxy resin multilayer copper coated laminated board - Google Patents

Abstract

PURPOSE:To improve adhesion strength of epoxy resin and a copper foil by using epoxy resin having three or more epoxy radicals in one molecule and by attaching a titanate coupling agent to an oxidized surface of an inner layer copper foil. CONSTITUTION:Titanate coupling agent is attached to a rough side of copper foil. A mixture of epoxy resin which includes epoxy resin having three or more epoxy radicals in one molecular at least 10wt.% and a prepreg are laminated between two sheets of copper foil. The lamination is heated, pressurized, and cured to acquire a lamination whose both sides are coated with copper. Then, after specified pattern etching is applied, it is immersed in black oxidation treatment solution to carry out oxidation treatment to a lustrous side of the copper foil. Furthermore, after the lamination is immersed in water solution of titanate coupling agent, the prepreg and the copper foil are laminated up and down. Thereafter, heating, pressurizing and curing are carried out to acquire a four-layer copper coated laminated board. Thereby, it is possible to improve adhesion of epoxy resin and a copper foil and to improve reliability of a fine pattern such as a high density printed substrate.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a multilayer copper-clad laminate using an epoxy resin, and more specifically, the present invention relates to a multilayer copper-clad laminate using an epoxy resin. The present invention relates to multilayer copper-clad laminates.

[Conventional technology]

In recent years, requirements for various properties of copper-clad laminates have become increasingly strict. This tendency is particularly noticeable in copper-clad laminates for industrial and consumer printed wiring boards.

For example, as signal lines become thinner and thinner due to the demand for higher density, the strength of the bond between copper foil and resin becomes important to ensure reliability. On the other hand, there is a noticeable trend toward multilayering, and the adhesive strength of copper foil is not only becoming rougher.

The relationship between the glossy surface and the resin is also important. Furthermore, advances in mounting formats have led to higher soldering temperatures.

Due to demands for dimensional stability during soldering and stability against warping and twisting, there is an increasing demand for improved heat resistance of resins. In response to these demands, in recent years, efforts have been made particularly to impart heat resistance to epoxy resins, even in the case of epoxy resin copper-clad laminates that are generally used in a wide range of industries.

That is, instead of the commonly used epoxy resin which has two epoxy groups in one molecule.

Epoxy resins having three or more epoxy groups in one molecule are used. This increases the crosslinking density after the curing reaction, thereby increasing the glass transition temperature (Tg) and improving heat resistance.

[Problem to be solved by the invention]

However, these epoxy resins having three or more epoxy groups in one molecule have never been satisfactory in improving the adhesive strength between copper foil and epoxy resin, which is another important property.

In particular, in the case of multilayer copper-clad laminates, there is a problem in that the adhesive strength between the resin and the oxidized surface (typically black oxide treatment and brown oxide treatment) that is usually performed on the shiny surface of the inner steel layer is low. .

This is because as heat resistance improves due to increased crosslinking density, the resin inevitably tends to become harder and more brittle, resulting in a decrease in adhesion at the interface with the oxidized surface of the steel foil, especially in beer strength. There were problems - The present invention was made to solve the above problems, and it uses an epoxy resin with improved heat resistance and has three or more epoxy groups in one molecule. The purpose of the present invention is to obtain an epoxy resin multilayer copper-clad laminate with improved adhesive strength between the inner layer steel foil and the oxidized surface.

[Means to solve the problem]

The epoxy resin multilayer copper-clad laminate of the present invention has three
Adhesive strength is improved by using an epoxy resin having at least three epoxy groups and by attaching a titanate coupling agent to the oxidized surface of the inner layer copper foil.

In the present invention, the oxidation treatment applied to the glossy surface of the inner layer copper foil refers to, for example, "
Refers to the oxidation treatment commonly used in the printed wiring board industry, as shown on pages 549 to 553 of "Printed Circuit Technology Handbook."

In the present invention, an epoxy resin mixture containing at least 10% by weight of an epoxy resin having three or more epoxy groups in one molecule is used, and a titanate coupling agent is applied to the oxidized surface applied to the shiny surface of the inner layer copper foil. It is preferable to form an epoxy resin multilayer copper-clad laminate using an inner layer steel foil to which the epoxy resin is attached.

[For production]

The reasons for the improvement in adhesive strength by the titanate coupling agent in the present invention are considered to be largely due to the following three points.

■ The hydrogen atoms of the alkoxy groups and phosphoric acid groups, which are the hydrophilic groups of the titanate coupling agent, form hydrogen bonds with the oxygen atoms of the oxidized steel present on the oxidized surface of the copper foil, and the hydrocarbon moieties, which are the lipophilic groups, form hydrogen bonds with the epoxy resin. By being compatible with this material, great adhesive strength is exhibited.

■ A relatively soft layer made of titanate coupling agent exists at the interface between the copper foil and the epoxy resin layer, which relieves peeling stress during copper foil beer brewing.

■ The water molecules that are normally adsorbed on the outermost surface of the copper foil are replaced with the titanate coupling agent, thereby exerting its inherent adhesive strength.

Examples of titanate coupling agents having the above-mentioned effects include isopropyl triisoste 70yl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphite) titanate, tetraisopropyl bis (dioctyl pyrophosphite) titanate, and tetraisopropyl bis (dioctyl pyrophosphite) titanate. Octylbis(ditridecylphosphite) titanate, tetra(
2゜2-Diallyloxymethyl-1-butyl)bis(di-tridecyl)phosphite titanate, bis(dioctylpyrophosphate)oxyacetate titanate, bis(dioctylpyrophosphate)ethylene titanate, isopropyltrioctanoyltitanate, isopropyl dimethacrylate isostearoyl titanate,
isopropyl isostearoyl diacrylic titanate,
Isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, isopropyl tri(N-amidoethylaminoethyl) titanate, dicumylphenyloxyacetate titanate,
Examples include diisostearoyl ethylene titanate. These titanate coupling agents may be used alone or in combination.

Typical epoxy resins having three or more epoxy groups in one molecule include Epicoat 1031, Epicoat 152, and Epicoat 154 manufactured by Yuka Shell Epoxy Co., Ltd.
, YH-434 manufactured by Tobu Kasei Co., Ltd., TAC manufactured by Dow Chemical Company
TIX-742, EPPN501 manufactured by Nippon Kayaku Co., Ltd. (&N are also trade names), and the like. These epoxy resins may be used alone, or may be used in combination of several types, and may be used in combination with a commonly used epoxy resin having two epoxy groups in one molecule. ,
In that case, the effect of the titanate coupling agent of the present invention is exhibited in an epoxy resin mixture containing at least IO weight % of an epoxy resin having three or more epoxy groups in one molecule. That is, when 10% by weight is not added, the effect is not significant.

As for the curing agent, those normally used as curing agents for epoxy resins can be used as they are. For example, amine curing agents such as -class amine type, secondary amine type, tertiary amine type, aromatic amine type, acid anhydride type curing agent, polyamide resin type curing agent, phenolic resin type curing agent, dicyandiamide and 8F, .

Catalytic curing agents such as monoethylamine, imidazole curing agents, and the like can be used alone or in combination.

In addition, the fiber base materials used as reinforcing fibers for epoxy resins include not only glass fibers, but also inorganic fibers such as quartz fibers, silicon carbide fibers, alumina fibers, and aramid fibers! ll
Organic fibers such as fibers and polyethylene fibers can also be used.

〔Example〕

Next, examples of the present invention will be described.

Example 1 Bis(dioctyl pyrophosphate) oxyacetate titanate (Ajinomoto Co. 11: trade name, Prene Act 1)
A 1% by weight MEK solution of 38s) was prepared. Separately, Epicoat 1031 manufactured by Yuka Shell Epoxy Co., Ltd. and an epoxy resin composition containing 4% by weight of dicyandiamide as a curing agent and 5M Schniebel #7628.
Three sheets of prepreg made of glass cloth were laminated, and 35μ steel foil was layered on top and bottom with the roughened side facing the prepreg.
A double-sided steel clad laminate with a wall thickness of 0.6 mm was obtained by curing at 170 DEG C. for 2 hours in a hot press, and subsequently etched in a predetermined pattern.

Next, this pattern-etched double-sided copper-clad laminate was treated with a black oxidizing solution (sodium chlorite 31 g/a, sodium hydroxide 15 g/12, trisodium phosphate 12 g,
1 aqueous solution) at 95°C for 2 minutes, then rinsed with water, and
It was dried in an oven at 50° C. for 15 minutes to obtain a double-sided steel-clad laminate whose glossy copper foil surface was treated with black oxidation. Further, this laminate was immersed in the titanate coupling agent MEK solution for 1 minute, and then dried in an oven at 100° C. for 5 minutes. After laminating two sheets of the above-mentioned prepreg and further 18μ copper foil on the upper and lower sides of the double-sided copper-clad laminate obtained in this way, they were cured by heating and pressing at 170°C for 2 hours in a hot press. A layered copper-clad laminate was obtained.

Table 1 shows the results of measuring the beer strength of the black oxidized surface of the 35μ metal foil of the inner layer of this laminate at 20°C in accordance with JIS-C-6481.

Example 2 Tetraisopropyl bis(dioctyl phosphite) titanate (manufactured by Ajinomoto Co., Ltd., trade name, Prene Act 41B) was used as the titanate coupling agent, and Epicoat 154 was used as the epoxy resin.

Table 1 shows the results of measuring the beer strength of the black oxidized surface of the inner layer 35μ copper foil in the same manner as in Example 1.

Example 3 Isopropyl tridodecylbenzenesulfonyl titanate (manufactured by Ajinomoto Co., Inc., trade name, Prene Act 9S) was used as a titanate coupling agent, Epicoat 154 was used as an epoxy resin, and diaminodiphenylsulfone was used as a curing agent at 20% by weight based on the epoxy resin. In addition to using
Table 1 shows the results of measuring the beer strength of the black oxidized surface of the inner layer 35μ copper foil in the same manner as in Example 1.

Example 4 Isopropyl tri(N
-amidoethylaminoethyl) titanate (manufactured by Ajinomoto Co., Inc.; trade name, Prene Act 44), Y as an epoxy resin
The beer strength of the black oxidized surface of the inner layer 35μ steel foil was measured in the same manner as in Example 1, except that H-434 was used and diaminodiphenylmethane was used as a curing agent at 20% by weight based on the epoxy resin. The results of the measurements are shown in Table 1.

Example 5 In the same manner as in Example 1, except that TACTIX-742 was used as the epoxy resin and polyvinylphenol (trade name Niresin M, manufactured by Marukubi Sekiyu Co., Ltd.) was used as a curing agent in an amount of 80% by weight based on the epoxy resin. Table 1 shows the results of measuring the beer strength of the black oxidized surface of the 35μ copper foil serving as the inner layer.

Example 6 Table 1 shows the results of measuring the beer strength of the black oxidized surface of the 35 μm inner layer copper foil in the same manner as in Example 2, except that EPPN-501 was used as the epoxy resin.

Example 7 As an epoxy resin having two epoxy groups in one molecule, Epicoat 828 manufactured by Yuka Shell Epoxy Co., Ltd.
The beer strength of the black oxidized surface of the inner layer 35μ copper foil was measured in the same manner as in Example 2, except that an epoxy resin mixture containing 90% by weight of EPPN-501 and 10% by weight of EPPN-501 was used. It is shown in Table 1.

Example 8 50% by weight of Epicoat 828 as an epoxy resin, E
35% of the inner layer was prepared in the same manner as in Example 2, except that an epoxy resin mixture containing 50% by weight of PPN-501 was used.
Table 1 shows the results of measuring the beer strength of the black oxidized surface of μ copper foil.

Example 9 95% by weight of Epicoat 828 as an epoxy resin, E
A 35μ inner layer was prepared in the same manner as in Example 2, except that an epoxy resin mixture containing 5% by weight of PPM-501 was used.
Table 1 shows the results of measuring the beer strength of the black oxidized surface of the copper foil.

Comparative Examples 1 to 9 In Examples 1 to 9, the beer strength of the black oxidized surface of the 35μ copper foil of the inner layer was measured without the titanate coupling agent, and the results are shown in Table 2.

Table 1 Table 2 [Effects of the Invention] As described above, in the multilayer copper-clad laminate according to the present invention, since the titanate coupling agent is attached to the oxidized surface of the inner layer copper foil, three or more epoxy molecules are present in one molecule. It is possible to significantly improve the adhesion between the epoxy resin containing the base and the oxidized surface of the copper foil. Therefore, when applied to high-density, high-multilayer printed wiring boards, etc., the reliability of the fine patterns formed can be greatly improved. can be improved.

Claims (1)

[Claims] (1) An epoxy resin multilayer copper-clad laminate characterized in that an epoxy resin having three or more epoxy groups in one molecule is used and a titanate coupling agent is attached to the oxidized surface of the inner layer copper foil.