JP3095636B2 - Manufacturing method of metal foil clad laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a metal foil-clad laminate used as a material for a printed wiring board used for electronic and electric equipment.

[0002]

2. Description of the Related Art A printed wiring board is usually provided with a solder resist on the outermost conductive circuit pattern to prevent a short circuit due to soldering between the conductive circuit patterns at the time of soldering or to protect the surface of the conductive circuit pattern. It is formed.

As a method of forming the solder resist, a photographic printing method using a photosensitive resin (photoresist) has been used. This photographic printing method is a method in which a negative or positive mask is overlaid using a photoresist, and a circuit pattern is exposed by an exposure machine.

[0004] Exposure of a circuit pattern by this exposure machine is as follows.
From the viewpoint of workability, double-sided simultaneous exposure is employed. However, for example, when simultaneously exposing a metal foil-clad laminate as a material for a printed wiring board on both sides, light irradiated by an exposure machine passes through the photoresist, further passes through the inside of the laminate, and emits light in the ultraviolet region. However, the photoresist on the opposite side was sometimes exposed.

[0005] In particular, as the thickness of the metal foil-clad laminate becomes thinner, the transmittance becomes higher. For this reason, an ultraviolet absorber is added to the thermosetting resin composition impregnated into the base material, or the base material is increased in fluorescence. A method of treating with a whitening agent was used to prevent transmission of ultraviolet rays.

However, when these methods are used to prevent transmission of ultraviolet rays and produce a metal foil-clad laminate,
Due to the large amount of UV absorbers and fluorescent brighteners used, UV absorbers and fluorescent brighteners are not evenly dispersed in the metal foil-clad laminate, reducing the heat resistance of the metal foil-clad laminate. In addition, the light transmittance of the metal foil clad laminate varies, and the photoresist on the opposite surface is exposed.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to maintain the appearance and various characteristics of an original metal foil-clad laminate while transmitting light. An object of the present invention is to provide a metal-foil-clad laminate having a uniform rate and excellent ultraviolet absorption.

[0008]

According to a first aspect of the present invention, there is provided a method of manufacturing a metal foil-clad laminate, comprising the steps of: providing a metal varnish containing a thermosetting resin on a substrate; In the method for producing a metal foil-clad laminate obtained by laminating and integrating foils, as the prepreg, a fluorescent dye that absorbs ultraviolet light is previously dissolved in a radical polymerizable compound to form a fluorescent composition, and the compatibility with the radical polymerizable compound is determined. A varnish obtained by dissolving the fluorescent composition and the thermosetting resin in a catalyst having the varnish, and using a prepreg obtained by impregnating the varnish into a base material.

Further, in the method for producing a metal foil-clad laminate according to claim 2 of the present invention, the content of the fluorescent dye is 0.03 to 5.0% by weight based on the thermosetting resin component. There is a feature.

Hereinafter, the present invention will be described in more detail. The fluorescent dye used in the method for producing a metal foil-clad laminate of the present invention is a fluorescent dye that absorbs light in an arbitrary range,
The ultraviolet absorption wavelength region of the fluorescent dye preferably occupies the photosensitive wavelength region of the ultraviolet-curable solder resist used at the time of forming a circuit pattern.
It is preferably nm. The content of the fluorescent dye was 0.03 with respect to the thermosetting resin composition.
To 5.0% by weight, preferably 0.03% by weight.
If it is less than the weight%, the combined effect cannot be obtained,
Light is transmitted when manufacturing a printed wiring board. Also,
If it exceeds 5.0% by weight, the effect of blocking light is improved, but the heat resistance of the obtained metal foil-clad laminate is reduced.

A typical radical polymerizable compound that dissolves the fluorescent dye is a monomer containing a vinyl group,
In the liquid state, the fluorescent dye has a high dissolution rate and can be uniformly dispersed. The radical polymerizable compound is not particularly limited, but examples thereof include aromatic vinyl compounds such as styrene, vinyltoluene, divinylbenzene, α-methylstyrene, and chlorostyrene; vinyl esters such as vinyl acetate and divinyl adipate. Classes: diallyl phthalate; (meth) acrylic acid; (meth) such as methyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, ethylene glycol di (meth) acrylate, and 2-hydroxyethyl (meth) acrylate Acrylic esters and the like can be mentioned. Among these, styrene is particularly preferred because of its particularly good solvent performance and polymerization reaction. The radical polymerizable compound is used alone or in plural.

The thermosetting resin composition in which the fluorescent dye is dissolved is not particularly limited, and is a thermosetting resin composition used for manufacturing a laminate, for example, an unsaturated polyester resin, an epoxy resin, Any of a vinyl ester resin, a phenol resin, a polyimide resin and the like can be used alone, as a modified product, or as a mixture. If necessary, a filler such as a hollow body such as aluminum hydroxide, clay, talc, silica, alumina, magnesium carbonate, calcium carbonate, synthetic resin powder, or glass can be added to the above resin.

As the solvent used for dissolving the thermosetting resin, various solvents are used depending on the type of the thermosetting resin. Examples thereof include methyl ethyl ketone, acetone, and toluene. This solvent is not used depending on the production process.

The substrate to be impregnated with the varnish obtained by dissolving the fluorescent dye and the thermosetting resin in a catalyst is not particularly limited as long as it is a substrate used when forming a laminate. For example, a glass woven fabric, a glass nonwoven fabric, or the like is used.

As the above metal foil, copper, aluminum,
Single or alloy metal foil of iron, nickel, zinc or the like can be used.

[0016]

Next, examples of the present invention and comparative examples will be described.

First, the following fluorescent dyes 1 and 2 were mixed with styrene, which is a radical polymerizable compound, based on the compounding ratio used in Examples 1 and 2 and Comparative Examples 1 to 3 shown in Table 1, and the mixture was stirred with a stirrer. It is added and dissolved to produce a fluorescent composition.

Fluorescent dye 1: 1.3- (phenyl) -5
-(4-TERT-butyl-phenyl) -pyrazoline
: Neo Super HR-101 manufactured by Chuo Gosei Kagaku Co., Ltd. Maximum absorption wavelength region: 355 to 359 nm Absorption wavelength region: 334 to 380 nm Fluorescent dye 2: 1- (phenyl) -3- (4-TERT)
-Butyl-styryl) -5- (4-TERT-butyl-
Phenyl) -pyrazolin: Neosuper HR-50 manufactured by Chuo Gosei Kagaku Co., Ltd. Maximum absorption wavelength region: 385 to 389 nm Absorption wavelength region: 364 to 416 nm Next, as a thermosetting resin, an unsaturated polyester (Takeda Pharmaceutical Co., Ltd. Takeda Polymer 6320F)
0 parts by weight, 1 part by weight of benzoyl peroxide as a catalyst, 20 parts by weight of aluminum hydroxide, and further, the fluorescent composition obtained above was added to form a varnish. 0.35m
m).

In the above process, for Comparative Example 4,
100 parts by weight of unsaturated polyester (Takeda Polymer 6320F manufactured by Takeda Pharmaceutical Co., Ltd.), 1 part by weight of benzoyl peroxide, 20 parts by weight of aluminum hydroxide, and 40% by weight of fluorescent dye 1 based on thermosetting resin In addition, styrene is further added to mix a varnish, and this varnish is made of a glass nonwoven fabric (manufactured by Olivet, thickness 0.35).
mm) to form a prepreg.

Each of the prepregs obtained above is
Copper foil for electrical laminate
m), a laminate was obtained by laminating two sheets on the treated surface and further laminating the above-mentioned copper foil for electric laminate on the laminate.

The laminate is continuously sent to a curing furnace, and heated in a curing furnace at 100 ° C. for 15 minutes, and then at 130 ° C. for 20 minutes, and the resin is cured by heating and integrated to obtain a thickness. A metal foil-clad laminate having a thickness of 0.8 mm was obtained.

The resulting metal foil-clad laminate was evaluated for light transmittance and heat resistance by the following test methods. The results are shown in Table 1 below.

For the light transmittance, the obtained metal foil-clad laminate is etched to remove copper, and a photoresist (RSR-4000, manufactured by Taiyo Ink Co., Ltd.) is applied to both sides of the substrate from which copper has been removed. The substrate was coated and dried, and a negative film having a predetermined circuit pattern formed thereon was applied to the surface of the substrate and irradiated with ultraviolet rays. Then, the substrate was developed with a sodium carbonate solution, and the light transmittance was evaluated based on the presence or absence of the resist on the back surface of the substrate.

The heat resistance is measured by removing the copper by etching the obtained metal foil-clad laminate and subjecting the substrate from which the copper has been removed to a pressure cooker test (PCT: 3 atm, 134 atm).
(Treated at 90 ° C. for 90 minutes), and then dipped in a solder bath at 260 ° C. for 180 seconds to evaluate the heat resistance based on the presence or absence of blisters on the substrate surface.

[0025]

[Table 1]

As shown in Table 1, the metal foil-clad laminates in Examples 1 and 2 of the present invention were prepared by dissolving a fluorescent dye in styrene in advance to obtain a thermosetting resin composition for impregnation. And can uniformly block light without exposing the photoresist on the back surface during exposure.
In addition, the amount of the fluorescent dye, based on the resin component,
Since it is 0.03 to 5.0% by weight, it can be seen that there is no blister on the surface and the heat resistance is excellent.

Furthermore, compared to Comparative Examples 2 and 3 in which one type of fluorescent dye is dissolved, two types of fluorescent dyes having different light absorption wavelength regions are dissolved, so that light is more effectively blocked. We can see that we can do it.

[0028]

According to the method for manufacturing a metal foil-clad laminate according to the present invention, a fluorescent dye that absorbs ultraviolet light is dissolved in a radical polymerizable compound in advance to form a fluorescent composition, and then the fluorescent composition is heated. The varnish is dissolved in the curable resin to form a varnish, and the prepreg impregnated with the varnish is used.Therefore, the metal foil-clad laminate obtained using this prepreg has a uniform dispersion of the fluorescent dye and a uniform It absorbs ultraviolet light, has an excellent light blocking effect, can expose the backside photoresist during exposure without exposing it to light, and has excellent heat resistance without impairing the properties of conventional laminates.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI // B32B 27/04 B32B 27/04 Z 27/20 27/20 Z

Claims (2)

(57) [Claims] 1. A method for producing a metal foil-clad laminate in which a metal foil is laminated and integrated on one or more prepregs containing a varnish containing a thermosetting resin on a base material, wherein the prepreg is made of an ultraviolet ray. The fluorescent dye to be absorbed is dissolved in a radical polymerizable compound in advance to form a fluorescent composition, and a catalyst having compatibility with the radical polymerizable compound is dissolved in the fluorescent composition and a thermosetting resin to form a varnish. A method for producing a metal-foil-clad laminate, comprising using a prepreg obtained by impregnating a base material with a varnish. 2. The metal foil clad laminate according to claim 1, wherein the amount of the fluorescent dye is 0.03 to 5.0% by weight based on the thermosetting resin component of the varnish. Method.