JPH0192237A - Production of copper-clad laminated sheet - Google Patents

Abstract

PURPOSE:To obtain a laminated sheet having excellent heat resistance, water- vapor resistance and punchability, by applying specific epoxy resin varnish to nonwoven fabric to give plural sheets of prepreg, piling prepreg prepared by coating nonwoven fabric with resin varnish containing no filler on both sides of the top and the bottom of the prepreg and further laminating a copper foil to the piled prepreg. CONSTITUTION:Epoxy resin varnish comprising (A) an epoxy resin, (B) an aromatic amine (e.g., 4,4'-diamino-3,3',5,5'-tetramethyldiphenylmethane) shown by the formula (R<1>-R<4> are alkyl), (C) dicyandiamide, (D) a filler, (E) a curing agent and (F) an organic solvent as essential components is applied to glass nonwoven fabric, impregnated to and dried to give plural sheets of prepreg and prepreg obtained by coating and impregnating glass nonwoven fabric with epoxy resin varnish containing no filler, followed by drying is piled to both sides of the top and the bottom of the prepreg. Further a copper foil is laminated to the surface of the prepreg, which is hot-pressed and molded in one piece to give the aimed laminated sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of the Invention (Industrial Application Field) The present invention relates to a method for manufacturing a copper-clad laminate having excellent heat resistance, moisture resistance, and punching workability.

(Prior Art) In recent years, the development of electronic devices has been remarkable, and copper-clad laminates have been used in a wide variety of ways, and those with excellent characteristics have been required. In particular, as the density of wiring increases, finer patterns and through holes become smaller in diameter, and copper-clad laminates with better drilling and punching properties are required more than ever before.

On the other hand, with the demand for improved productivity and lower costs, increasingly strict processing conditions such as hot air levelers and flow soldering are being added to the wiring board mounting process. In terms of durability and moisture resistance, there is a growing demand for products with even better durability and moisture resistance than ever before.

In order to meet these demands, copper-clad M-laminates based on glass non-woven fabric are being used, and they have the same electrical properties as glass-epoxy laminates based on woven glass fabric, and are more competitive. Because it is easy to punch, its productivity is rapidly increasing.

The epoxy resin varnish used for copper-clad laminates based on glass nonwoven fabric is a mixture of bisphenol A epoxy resin, curing agents such as dicyandiamide, acid anhydride, and phenol novolac resin, and is mixed with an appropriate amount of solvent. It is used diluted.

(Problems to be Solved by the Invention) However, when dicyandiamide is used as a curing agent, although it has excellent adhesive properties, the cured resin has a low glass transition point and poor heat resistance after moisture absorption. There was a problem. When an acid anhydride is used, although a high glass transition point can be obtained, there are problems in that the pot life of the prepreg is short and the cured product becomes hard, making it difficult to crack during punching. Furthermore, when a phenol novolak resin is used, although the heat resistance is improved, there are problems in that the heat resistance after moisture absorption and the adhesive strength of the copper foil are low.

Furthermore, copper-clad laminates based on non-woven glass fabric have superior drilling and punching properties compared to copper-clad laminates based on woven glass fabric, but have poor heat resistance and moisture resistance. The problem was that they were inferior in gender.

The present invention was made to solve these problems, and an object of the present invention is to provide a method for manufacturing a copper-clad laminate having excellent heat resistance, moisture resistance, and punching workability.

[Structure of the Invention] (Means for Solving the Problems) As a result of diligent research to achieve the above object, the present inventors have discovered that specific aromatic amines and dicyandiamide are used as curing agents for epoxy resins. By using an epoxy resin varnish containing a filler and an epoxy resin varnish containing no filler, and using glass nonwoven fabric and glass woven fabric as the base material, heat resistance, moisture resistance, and punching workability are improved. It was discovered that a smooth copper 8N laminate could be obtained, and the present invention was completed. That is, the present invention provides (A) an epoxy resin, (B) an aromatic amine represented by the general formula (wherein R', R2, R3, and R' represent the same or different alkyl groups); C) A plurality of sheets of prepreg made by applying, impregnating, and drying an epoxy resin varnish on a glass nonwoven fabric, the essential components of which are dicyandiamide, (D>filler, (E) hardening accelerator, and (F) organic solvent); A prepreg formed by applying, impregnating, and drying the above-mentioned epoxy resin varnish that does not contain a filler to a glass woven fabric on both the upper and lower surfaces is layered, and then copper foil is layered on at least one side of the prepreg and heated and pressurized to form an integral piece. This is a method for manufacturing a copper-clad laminate, which is characterized by the following: The epoxy resin varnish contains (A) 100 parts by weight of epoxy resin, (B) 1 to 30 parts by weight of aromatic amine, and (C) 1 to 30 parts by weight of dicyandiamide. This is a method for manufacturing a copper-clad laminate using an epoxy resin varnish containing 20 to 100 parts by weight of filler (D) and filler (D).

The present invention will be explained in detail below.

As the epoxy resin (A) used in the present invention, any epoxy resin having two or more epoxy groups in one molecule can be used.

For example, glycidyl ether type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak epoxy resin, or brominated products thereof, other glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, alicyclic epoxy resins, Examples include heterocyclic epoxy resins, which may be used alone or in combination of two or more.

The aromatic amine represented by the general formula <8) (wherein R', R', R', and R' represent the same or different alkyl groups) used in the present invention includes, for example, specific compounds. Examples include 4,4'-diamino-3,3', 5,5'-tetramethyldiphenylmethane, 4,4'-diamino-3,3'-diethyl-
Examples include 5,5'-dimethyldiphenylmethane, which may be used alone or in combination of two or more as a curing agent. The blending ratio of the aromatic amine is preferably 1 to 30 parts by weight per 100 parts by weight of the above-mentioned (A) epoxy resin.If the aromatic amine is less than 1 part by weight, sufficient heat resistance cannot be obtained; Moreover, if it exceeds 30 parts by weight, unreacted amino groups remain in the cured product, resulting in a decrease in moisture resistance, which is not preferable.

As (C) dicyandiamide used as another curing agent in the present invention, commercially available products can be widely used and are not particularly limited. This dicyandiamide can be used in combination with the above-mentioned (B) aromatic amine. However, the blending ratio of dicyandiamide is preferably 1 to 4 parts by weight per 100 parts by weight of the epoxy resin (A).

If the amount of dicyandiamide is less than 1 part by weight, the adhesive strength with the copper foil will decrease, and if it exceeds 1 part by weight of 41J, unreacted amino groups will remain in the cured product, resulting in a decrease in moisture resistance, which is not preferable.

Examples of the filler (D) used in the present invention include E glass powder, aluminum hydroxide, magnesium hydroxide, alumina, magnesium oxide, titanium dioxide, potassium titanate, and calcium silicate.

Inorganic fillers such as aluminum silicate and calcium carbonate, polyethylene V! i fat, poly-10 pyrene resin.

Borisdylene resin, polyvinyl chloride resin, polyamide resin, polyester resin, phenolic resin.

Organic fillers such as epoxy resins and melamine resins can be used in the form of pieces or powders, and these can be used alone or in combination of two or more. The blending ratio of filler is (
A) It is desirable to mix 20 to 100 parts by weight with respect to 100 parts by weight of epoxy resin.

If the amount of the filler is less than 20 parts by weight, the effect of improving the heat resistance and dimensional stability of the %1 layered laminate will be small, and if it exceeds 100 parts by weight, the drilling workability and punching workability will deteriorate, which is not preferable.

Examples of the curing accelerator (E) used in the present invention include imidazoles, BF2-amine compounds, aluminum chelate/silicone compounds, tertiary amine compounds, and phosphorus compounds such as triphenylphosphine. They can be used alone or in a mixture of two or more.

The organic solvent (F) used in the present invention includes, for example, acetone, methyl ethyl getone, dimethyl formamide, toluene, etc., and is not particularly limited as long as it can dissolve the resin component described above, and can be widely used. be able to.

Each component explained above (A) epoxy resin, <8) aromatic amine, (C) dicyandiamide, (D) filler, (E
) A curing accelerator and (F) an organic solvent can be blended as essential components and uniformly dissolved to prepare an epoxy resin varnish.

A prepreg can be obtained by applying the epoxy resin varnish thus obtained to a glass nonwoven fabric and impregnating it, and then drying to semi-cure the epoxy resin.
Similarly, a prepreg can be obtained by applying an epoxy resin varnish containing no filler to a glass woven fabric by a conventional method, impregnating it, and then drying it to semi-cure the epoxy resin.

The method for manufacturing a copper-clad laminate of the present invention includes stacking a plurality of sheets of prepreg using the above-mentioned glass non-woven fabric and prepreg using the above-mentioned glass woven fabric on both upper and lower surfaces, and further coating copper foil on at least one side of the prepreg. It can be manufactured by stacking them together, heating and pressing them, and molding them into one piece.

(Function) The epoxy resin varnish used in the present invention was able to produce a copper-clad laminate with excellent properties by blending a specific amine as a hardening agent, dicyandiamide, and a filler. While retaining the excellent adhesion and long pot life of dicyandiamide, the addition of aromatic amines improves heat resistance and moisture resistance, and the addition of fillers improves punching processability. Drillability can be improved. Furthermore, by using the glass nonwoven fabric, punching workability and drilling workability can be synergistically improved.

(Example) Next, the present invention will be specifically explained using examples.

In the following examples and comparative examples, [parts] means "parts by weight."

Example 1 Bisphenol A epoxy resin (epoxy equivalent: 480
g/eq) 100 parts, 4,4'-diamino-3,
3'.

5.5 parts of 5'-tetramethyldiphenylmethane, 2 parts of dicyandiamide, 60 parts of aluminum hydroxide powder, 2-
0.2 parts of ethyl-4-methylimidazole, 20 parts of dimethylformamide and 60 parts of acetone were added and uniformly dissolved with stirring to prepare an epoxy resin varnish. Next 4
The above epoxy resin varnish was coated and impregnated on 0 μl of glass nonwoven fabric, and dried at a temperature of 160°C to prepare prepreg (I).
In the same manner, using a glass woven cloth with a thickness of 180 μl, the epoxy resin varnish containing no aluminum hydroxide was applied, impregnated, and dried to prepare a prepreg (II).
) was created.

Next, 6 sheets of prepreg (I) are stacked, one sheet of prepreg (U) is placed on each of the top and bottom surfaces, and one sheet of copper foil with a thickness of 18 μm is placed on each of the top and bottom surfaces of prepreg (II). Temperature of 170℃, 40 parts M
A copper-clad laminate with a thickness of 1 and 6 ml was produced by integrally molding the product under heat and pressure for 90 minutes at a pressure of "CII".

The resulting copper-clad laminate was tested for specific properties, and the results are shown in Table 1. The present invention has excellent heat resistance, moisture resistance, and punching workability, and the effects of the present invention were confirmed.

Example 2 All procedures were carried out as in Example 1 except that 15 parts of 4.4'-diamino-3,3',5.5'-tetramethyldiphenylmethane as the aromatic amine in Example 1 was blended instead of 5 parts. A copper-clad laminate was manufactured in the same manner.

Further, the specific characteristics were tested in the same manner as in Example 1, and the results are shown in Table 1. The present invention has excellent heat resistance, moisture resistance, and punching workability, and the effects of the present invention were confirmed.

Example 3 In Example 1, 4,4'-diamino-3,3'-diethyl-5 was used instead of 4,4'-diamino-3,3',5,5'-tetramethyldiphenylmethane as the aromatic amine. A copper-clad laminate was manufactured in the same manner as in Example f3'lJ1 except that , 5'-dimethyldiphenylmethane was added. In addition, the specific characteristics were tested in the same manner and the results are shown in Table 1. The present invention has heat resistance, 1
It was excellent in IIF wettability and punching workability, and the effects of the present invention were confirmed.

Comparative Example 1 In Example 1, 4,4'-diamino-3,3',5
．． A copper-clad laminate was produced in the same manner as in Example 1 except that 5 parts of 5'-tetramethyldiphenylmethane was used and 4 parts of dicyandiamide was added instead of 2 parts of dicyandiamide. Further, the specific characteristics were tested in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2 Example 1 except that 35 parts of nadic acid was blended in place of 5 parts of 4,4'-diamino-3,3',5.5'-tetramethyldiphenylmethane and 2 parts of dicyandiamide as curing agents. A copper-clad laminate was manufactured in the same manner as in Example 1. In addition, the properties of the fibers were tested in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 3 In Example 1, phenol novolac resin (softening point 70°C) was used instead of 5 parts of 4,4'-diamino-3,3',5.5'-tetramethyldiphenylmethane and 2 parts of dicyandiamide as the curing agent. A copper-clad laminate was manufactured in the same manner as in Example 1 except that 20 parts of the copper clad laminate was added. In addition, the properties of the fibers were tested in the same manner as in Example 1, and the results are shown in Table 1.

41: Measured according to JIS-C-6481
j*2: Measured by DSC method*3: After stacking 4 copper foil samples and drilling 5000 holes using a 0.9II drill at a rotation speed of 70,0OOrp11 and a feed rate of 51/:min. Within the maximum of ``Average wall roughness *4: Presence or absence of cracks after external punching *5;
251ix25In sample with silver foil is floated in a solder bath at 300°C. Time taken until fluff appears.
After 5 hours of treatment at 2 atm at 260°C, the
The presence or absence of bags was investigated when immersed for seconds. ○...No bags were formed, △...More than half bags, X
...Effects of the Invention with All Closures] As is clear from the above explanation and Table 1, the effects of the @ tensioned laminate of the present invention! According to the deceased, certain aromatic amines,
Copper clad with excellent heat resistance, moisture resistance, and punching workability by using epoxy resin face combined with dicyandiamide and filler, and prepreg using both glass nonwoven fabric and glass woven fabric. Laminates can be manufactured.

Claims (1)

[Claims] 1 (A) Epoxy resin, (B) General formula ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (However, in the formula, R^1, R^2, R^3, R^4 are (representing the same or different alkyl groups), (C) dicyandiamide, (D) filler, (E) curing accelerator, and (F) organic solvent. A plurality of sheets of prepreg obtained by coating, impregnating, and drying a glass woven fabric, and a prepreg obtained by coating, impregnating, and drying a glass woven fabric with the epoxy resin varnish that does not contain a filler on both upper and lower surfaces thereof, and at least one side thereof. A method for producing a copper-clad laminate, which comprises stacking copper foil on top of the top and heating and pressurizing it to form it into one piece. 2. The epoxy resin varnish contains (A) 100 parts by weight of epoxy resin, (B) 1 to 30 parts by weight of aromatic amine, (C) 1 to 4 parts by weight of dicyandiamide, and (D) 20 parts by weight of filler. The method for producing a copper-clad laminate according to claim 1, wherein the epoxy resin varnish contains up to 100 parts by weight of the epoxy resin varnish.