JPS635930A - Manufacture of metal foil clad laminate - Google Patents

Abstract

PURPOSE:To give a laminate excellent ultraviolet absorbing capacity and prevent color development, thermal color change, eluation of ultraviolet absorbing agent through the surface of a board and lowering of glass transition temperature from occurring by a method wherein a prepreg impregnating with an epoxy resin composition, in the solid content of which specified ultraviolet absorbing agent is mixed, is employed as an inner layer. CONSTITUTION:In a manufacturing method of metal foil clad laminate produced by laminate-molding more than two glass cloth-based epoxy resin prepregs and metal foils, both of which are alternately piled up, one prepreg impregnating with an epoxy resin composition, to the solid content of which 0.2-6% by weight of ultraviolet absorbing agent represented by a general formula (1) is mixed, is employed as an inner layer. Because a constitution, in which at least each one prepreg being blended with ultraviolet absorbing agent and consequently having ultraviolet absorbing power is pinched by prepregs without ultraviolet absorbing agent, is realized, color development, thermal color change, eluation of ultraviolet absorbing agent through the surface of a board, lowering of glass transition temperature and the like do not occur. Glass non-woven cloth, glass cloth, mixed non-woven or woven cloth of glass fiber and other fiber is employed as glass cloth base material, the preferable thickness of which is 0.1-0.40mm.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for selectively forming a UV-sensitive resin film on the surface of a laminate after forming a printed wiring network. This is a manufacturing method for metal foil-clad laminates that solves the problem of UV light transmitting to the opposite side of the irradiated surface and exposing the UV-sensitive resin film on the opposite side, and does not cause deterioration in heat resistance, hue, etc. be.

[Conventional methods and their problems]

In the method of producing a metal foil-clad laminate by laminating and molding a prepreg made by impregnating and drying a glass nonwoven fabric or glass woven fabric with an epoxy resin and a metal foil, it is possible to prevent the transmission of ultraviolet rays, especially ultraviolet rays with a wavelength of 300 to 400 nm. In order to prevent this, there is a method of adding additives such as inorganic fillers and dyes to the resin composition, but this method has the disadvantage that the resulting laminate becomes opaque or colored. In addition, 2.6-sheet tert-butylphenol, 2-
A method of preventing the transmission of ultraviolet rays by blending an ultraviolet absorber such as hydroxy-84-n-octobezophenone is disclosed in Japanese Patent Application Laid-Open No. 1999-11103, but prepregs made simply by using mixed resins have been disclosed. In some cases, there is a drawback that the epoxy resin is colored as it is or the surface of the laminate plate is discolored by heating, and furthermore, the glass transition temperature of the cured epoxy resin is lowered.

[Means for solving problems]

As a result of extensive research into a method that solves the above problems, provides efficient ultraviolet absorption ability, and facilitates the manufacture of laminates, the present invention has been completed.

That is, the present invention provides a method for producing a metal foil-clad laminate in which three or more sheets of glass cloth base epoxy resin prepreg and metal foil are laminated and molded, and the solid content of the epoxy resin composition is as follows: A metal foil having ultraviolet absorbing ability, characterized in that one inner layer is a prepreg impregnated with an epoxy resin composition containing 0.2 to 6% by weight of an ultraviolet absorber represented by the general formula 2 full. In the method for producing stretched laminates, X+ (in the formula)
zn++: n is an integer from 1 to 6).

Since the structure is such that at least one prepreg with ultraviolet absorbing ability and containing an ultraviolet absorber is sandwiched between at least one prepreg that does not have an ordinary ultraviolet absorber,
Coloring, heat discoloration, elution of ultraviolet absorbers from the substrate surface,
This does not cause problems such as a decrease in glass transition temperature.

The present invention will be explained in detail below.

The glass cloth base material of the present invention is a glass nonwoven fabric, a glass woven fabric, a mixed nonwoven fabric or woven fabric of glass fiber and other fibers, which are usually used for laminates, and there are no particular restrictions on the thickness. 0.1 to 0.40 m<2> is suitable.

The epoxy resin composition of the present invention is not particularly limited and can be any one that is normally used for epoxy resin laminates. Specifically, bisphenol A epoxy resin, phenol novolak, etc. type epoxy resin, Talesol novolac type epoxy resin,
Brominated bisphenol A type epoxy resin, brominated phenol novolac type epoxy resin, other multifunctional epoxy resins and known curing agents, specifically phenols such as dicyandiamide, diaminodiphenylmethane, phenol novolac resin, acid anhydrides. etc. and curing accelerators, specifically 2-methylimidazole, 2-ethyl-
It is made using imidazoles such as 4-methylimidazole, 2-undecylimidazole, 2-heptadecyl imidazole, 2-phenylimidazole, and 1-benzyl-2-methylimidazole, and amines such as benzyldimethylamine. These compositions can be prepared as a solvent-free liquid composition or as a face dissolved in an organic fJ agent such as methyl ethyl ketone, acetone, or ethylene glycol monomethyl ether.

Specifically, the ultraviolet absorber of the above general formula (1) to be blended into the epoxy resin composition for the prepreg used as the inner layer of the present invention is 2-(2'-hydroxy-3').

5'-di-t-amylphenyl)benzotriazole,
Examples include 2-(2'-hydroxy-3',5''-di-t-butylphenyl)benzotriazole, and the blending amount ranges from 0.2 to 6% by weight based on the total solid content of the epoxy resin composition. If it is less than 0.2% by weight, the ultraviolet absorbing ability will be insufficient, and if it exceeds 6.0% by weight, various properties of the obtained metal foil-clad laminate will deteriorate, which is not preferable.

A prepreg is manufactured using the above components, one or more ordinary prepregs are placed on both sides of one prepreg having ultraviolet absorption ability, and a metal foil such as copper, aluminum, iron, etc. is further layered, By normal lamination molding methods, such as press, vacuum forming, autoclave molding, etc., under normal conditions, temperature 100 to 200°C, pressure 2 to 100 k
The metal foil-clad laminate of the present invention is manufactured by lamination molding at g/cJ for a time of 0.5 to 3 hours.

〔Example〕

Hereinafter, Examples and Comparative Examples will be shown and specifically explained. still,
"Parts" and "%" in Examples and Comparative Examples are based on weight unless otherwise specified.

Example-1 Brominated bisphenol A type epoxy resin (trade name: Epicote 1045, Br content 18-20χ, epoxy equivalent 450-500, manufactured by Yuka Shell Epoxy ■) 100
1 part, dicyandiamide 3.5 parts and 2-methylimidazole 0.2 parts with methyl ethyl ketone and N.

Dissolved in a mixed solvent of N-dimethylformamide, the thickness
Impregnated into a 0.18 mm plain weave glass woven fabric and heated at 160°C for 6
It was dried for a minute to produce prepreg (hereinafter referred to as "prepreg!") with a resin content of 45%.

The prepreg described above except that 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole (UV8-1) is further blended in the range of 0.5 to 4.0 parts. A prepreg with a resin content of 45% (hereinafter referred to as "prepreg ■") was produced in exactly the same manner as in (2).

Prepreg I was layered on both sides of prepreg ■ so that prepreg ■ was approximately in the center of the layered prepreg, and then electrolytic copper foil with a thickness of 35 Itm was layered and heated at a temperature of 170°C for 30 minutes.
A double-sided copper-clad laminate was manufactured by lamination molding at 0 kg/ctA for 2 hours.

After etching the obtained copper-clad laminate to remove the copper foil on both sides, it was irradiated with ultraviolet rays using high-pressure mercury or the like adjusted to an intensity of 20 W/a, and the wavelengths of 300 to 40 that passed through the laminate were etched.
The ultraviolet transmittance (UV
Transmittance) was determined. Further, a photoresist (trade name: Focus Coat, manufactured by Asahi Chemical Research Institute) was applied to both sides of this laminate, and the photosensitivity of the resist on the transparent surface was measured.

These results are shown in Table 1.

Example 2 In Example 1, the type of ultraviolet absorber used in the production of prepreg (2) was changed, and a laminate similar to Test 1) hl of Example 1 was produced and the same tests were conducted. Also, 260
The laminate was floated in a solder bath at ℃ for 20 seconds, and changes in the color tone of the laminate were observed.

The results are shown in Table 2.

Table 2 Example-3 Prepreg I obtained in Example-1 and 2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole (-1) VA-1) were A double-sided copper-clad laminate having a thickness of 1.61 cm was prepared by combining prepreg (2) containing .5 parts as shown in Table 3, and the glass transition temperature was measured.

The results are shown in Table 3.

Table 3 [Operations and Effects of the Invention] The laminate manufactured by the method for manufacturing a metal foil-clad laminate of the present invention as described above uses a specific ultraviolet absorber, so it has excellent ultraviolet absorption ability and Because the layer containing the ultraviolet absorber is placed approximately in the center of the laminate, problems such as coloring, discoloration by heating, elution of the ultraviolet absorber from the substrate surface, and lowering of the glass transition temperature are avoided. It has the following.

Claims (1)

[Claims] In a method for manufacturing a metal foil-clad laminate, which is formed by laminating and molding three or more glass cloth-based epoxy resin prepreg sheets and metal foil, the solid content of the epoxy resin composition is as follows: The ultraviolet absorber represented by the general formula (1) is 0.2 to 6
A method for manufacturing a metal foil-clad laminate having ultraviolet absorbing ability, characterized in that one inner layer is a prepreg impregnated with an epoxy resin composition mixed in weight percent. General formula (1): ▲There are mathematical formulas, chemical formulas, tables, etc.▼...
...(1) (X^1, X^2 in the formula are C_nH_z_n_+_1:
n is an integer from 1 to 6, and Y^1 and Y^2 are hydrogen atoms or C_nH_2_n_+_1: n is an integer from 1 to 6).