JPH10157011A - Copper-clad laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat resistance of a paper base material copper-clad laminate by a method wherein after impregrating paper base material with hydrophilic under coat resin, a copper foil is superimposed on a prepreg obtained by impregnating the treated paper base material with top coat resin containing a silane coupling agent, which is heated and pressurized. SOLUTION: Paper principally composed of cellurose fiber such as cotton paper, linter paper, kraft paper, etc., which are used as a laminate, is used as paper base material. As hydrophilic under coat resin with which that is inpregnated, a resin containing a hydrophilic polar base of a low molecular weight initial condensation product obtained by reacting phenol, cresol, melamine, urea, etc., with aldehyde group of formaldehyde, and paraformaldehyde under presence of an alkali catalyst is used. Then, phenol resin as the top coat resin and silane coupling are mixed, and dissolved in a solvent. The paper base is impregnated therewith as varnish, and dried to obtain a prepreg. A copper foil with an adhesive is superimposed on the specific number of sheets thereof, which are pressurized by heating to obtain a laminate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a copper-clad laminate, and more particularly to a paper-based copper-clad laminate.

[0002]

2. Description of the Related Art Copper-clad laminates based on paper are widely used as printed wiring board materials for consumer electronic devices. This is because the material itself is inexpensive, and processing is easy, such as cutting when processing into a wiring board and drilling for through holes, so that the processing cost can be reduced.

[0003] As is well known, a paper-based copper-clad laminate has a structure in which copper foil is attached to an insulating substrate using paper as a base material and a thermosetting resin such as phenol resin as a matrix. I have. And the paper base copper-clad laminate is craft paper,
It is manufactured by laminating a prepreg obtained by impregnating and drying a varnish of a thermosetting resin on a paper base material such as linter paper, followed by heating and pressing.

[0004] A paper base material is impregnated with a hydrophilic undercoat resin and dried,
A method of impregnating a thermosetting resin varnish thereon is a general method for producing a paper base prepreg. Cellulose fibers constituting the paper substrate have a large number of hydrophilic polar groups, and if directly impregnated with a thermosetting resin varnish, the affinity between the cellulose fibers and the thermosetting resin is poor. Is poor.

[0005]

In order to form a silver through-hole connection frequently used in a consumer printed wiring board,
After the silver paste is embedded in the through holes, the silver paste is cured by heating. Also, in the consumer printed wiring board, surface mounting has been adopted for mounting components, and accordingly, processes such as reflow soldering and solder dip have appeared. As described above, the paper base copper-clad laminate is required to have higher heat resistance because of being exposed to a high temperature. The present invention
It is an object of the present invention to improve the heat resistance of a paper-base copper-clad laminate.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a copper base is impregnated with a hydrophilic undercoat resin on a paper base material, and then a copper foil is overlaid on a prepreg obtained by impregnating a top coat resin containing a silane coupling agent. It is a copper-clad laminate obtained by pressing.

The amount of the silane coupling agent is preferably 0.2 to 5.0 parts by weight based on 100 parts by weight of the solid content of the overcoat resin. If the amount is less than 0.2 parts by weight, no effect can be expected. If the amount exceeds 5.0 parts by weight, other properties such as tracking resistance and drill workability may be adversely affected. For this reason, the blending amount of the silane coupling agent is 0.1 to 100 parts by weight of the solid content of the overcoat resin.
More preferably, it is 5 to 3 parts by weight. The silane coupling agent is a silane compound having an organic functional group having an affinity for a resin in the molecule, such as γ-ureidopropyltriethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ -Methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, N-β
(Aminoethyl) γ-aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercapto Propyltrimethoxysilane,
A silane compound known as a typical one such as γ-chloropropyltrimethoxysilane can be used.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As the paper base material used in the present invention, for example,
Paper mainly composed of cellulose fibers, such as cotton paper, linter paper, and kraft paper, is used. Mixed paper made by mixing other fibers such as glass fibers with cellulose fibers can also be used.

As the hydrophilic undercoat resin used in the present invention, a resin containing a hydrophilic polar group is used. For example,
Examples include low molecular weight precondensates obtained by reacting phenol, cresol, melamine, urea, etc. with aldehydes of formaldehyde and paraformaldehyde in the presence of an alkali catalyst.

The overcoat resin used in the present invention includes:
Phenol resins, unsaturated polyester resins and the like can be mentioned.

Among them, a resole resin obtained by reacting a phenol with an aldehyde in the presence of an alkali catalyst such as ammonia is used as the phenol resin. Phenols include phenol, meta-cresol, para-cresol, ortho-cresol, isopropylphenol, para-tert-butylphenol,
Paraisopropenyl phenol oligomer, nonyl phenol, bisphenol A and the like are used. Examples of the aldehyde include formaldehyde, paraformaldehyde, acetaldehyde, paraacetaldehyde, butyraldehyde, octylaldehyde, and benzaldehyde. Often, formaldehyde or paraformaldehyde is used. In order to impart flexibility to the laminate, the resol resin is preferably modified with a drying oil. A phenol and a drying oil are reacted in the presence of an acid catalyst, and then an aldehyde is reacted in the presence of an alkali catalyst to obtain a drying oil-modified resole resin. As the drying oil, tung oil, linseed oil, dehydrated castor oil, deer oil, etc. are used. A phenol resin and a silane coupling agent are mixed, dissolved in a solvent, and impregnated into a paper base as a varnish and dried to obtain a prepreg. As a solvent for forming a varnish, toluene, methanol, methyl ethyl ketone, 2-methoxyethanol, acetone, styrene and the like are used alone or in combination.

A predetermined number of the obtained prepregs are laminated with a copper foil with an adhesive, at a temperature of 150 to 180 ° C. and a pressure of 8 to 20 MPa.
By heating and pressing at a, a phenol resin copper-clad laminate is obtained.

[0013]

【Example】

Example 1 37 parts of tung oil (parts by weight, the same applies hereinafter), 63 parts of phenol,
Charge 0.05 parts of paratoluenesulfonic acid into a reaction kettle,
The reaction was performed at 90 ° C. for 1 hour to obtain a tung oil-phenol reaction product having a tung oil modification rate of 37% by weight.

To 100 parts of the obtained tung oil-phenol reaction product, 30 parts of paraformaldehyde and 7 parts of 28% by weight ammonia water were charged into a reaction vessel, reacted at 75 ° C. for 2 hours, and then dehydrated and concentrated under reduced pressure. Then, a resol resin was obtained, to which 1.0 part of γ-ureidopropyltriethoxysilane was added as a silane coupling agent and 75 parts of a mixed solvent having a weight ratio of toluene / methanol = 3/1 was added as a solvent. To give an overcoated resin varnish.

A water-soluble phenol resin (VP-03N (trade name, manufactured by Hitachi Chemical Co., Ltd.) was used as a hydrophilic undercoat resin) on kraft paper having a thickness of 0.2 mm and a basis weight of 125 g / m ^2. Then, the applied varnish was dried so that the total amount of the hydrophilic undercoat resin and the overcoated resin was 53%.
The prepreg was impregnated and dried to give a weight%.
Eight sheets of this prepreg are stacked, and one sheet of copper foil with an adhesive is stacked on both sides thereof at a temperature of 170 ° C. and a pressure of 11 MPa.
The mixture was heated and pressed for 5 minutes to produce a double-sided copper-clad laminate having a thickness of 1.6 mm.

Comparative Example 1 A double-sided copper-clad laminate having a thickness of 1.6 mm was produced in the same manner as in Example 1 except that the silane coupling agent was not added. For each of the copper-clad laminates of the examples and comparative examples, solder heat resistance and air heat resistance were examined. Table 1 shows the results.
The test method was as shown below.

Solder heat resistance (according to JIS C 6481) A test piece was cut into a 50 mm square, and the copper foil on one side was removed by etching on the entire surface, and the copper foil on the other side was removed only by half on a test piece. In a solder bath heated to ℃, float the copper foil with the surface facing down so that the surface contacts the solder, and measure the time until blistering occurs.

Heat resistance in air (according to JIS C 6481) A test piece cut into a square of 50 mm is put into a thermostat kept at 200 ° C., and after a predetermined time has elapsed, the test piece is taken out, and the presence or absence of blisters is examined. Record the longest time you haven't.

[0019]

[Table 1]

[0020]

According to the present invention, a paper-based copper-clad laminate excellent in heat resistance can be obtained.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunaga Sakai 1500 Ogawa Oji, Shimodate City, Ibaraki Prefecture Inside the Shimodate Plant of Hitachi Chemical Co., Ltd.

Claims (1)

[Claims] 1. A copper-clad laminate obtained by impregnating a paper base material with a hydrophilic undercoat resin and then impregnating a prepreg obtained by impregnating an overcoat resin containing a silane coupling agent with heat and pressurizing. .