JPH05245984A - Electric laminated sheet - Google Patents

Abstract

PURPOSE:To prevent that resist ink applied on an opposite side is photosensitized in a case exposed to ultraviolet rays of 380-420nm and a hue change is generated by using a resin compounded with a specific benzoxazolylthiophene compd. and a specific pyrazoline compd. as a matrix. CONSTITUTION:A resin compounded with a benzoxazolylthiophene compd. represented by formula I and a pyrazoline comp. represented by formula II is used as a matrix. In the formula I R1 and R2 are hydrogen, halogen or a 1-6C alkyl group and, in the formula II, R1, R2 and R4 are hydrogen, a 1-6C alkyl group or a phenyl group (which may be substituted with halogen or an alkyl group) and R3 is a methylene group, an ethylene group, a propylene group, a carbonyl group or a phenylethylene group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric laminate suitable for producing a printed wiring board using a UV curable resist ink. The laminated plate in the present invention refers to a laminated plate obtained by impregnating a base material with a thermosetting resin and applying heat and pressure, that is, a laminated plate having a thermosetting resin as a matrix, and a metal foil attached to one side or both sides. Including metal foil-clad laminates.

[0002]

2. Description of the Related Art In recent years, the wiring density of printed wiring boards has increased, and the number of methods using a photosensitive resist ink has increased in the solder resist printing as well as the method using a screen printing method.

The ultraviolet curable photosensitive resist ink is cured by irradiating it with ultraviolet rays. However, the irradiated ultraviolet rays may pass through the laminated plate, and when resist ink is applied to both surfaces, the resist ink on the opposite surface is also exposed in the same manner as the irradiated surface, and the predetermined pattern is formed on the opposite surface. Cannot be formed.

When the irradiation dose is reduced, the resist ink is insufficiently cured, and the abrasion resistance, solvent resistance and moisture resistance are impaired. Therefore, conventionally, an addition type ultraviolet absorber such as a benzophenone type, a benzotriazole type, or a coumarin type has been compounded in the resin.

These ultraviolet absorbers absorb only ultraviolet rays having a wavelength of 380 nm or less. For example, most benzophenone-based UV absorbers have an absorption peak near 270 to 290 nm, and both benzotriazole-based UV absorbers and coumarin-based UV absorbers have 340 to 340 nm.
There is an absorption peak near 360 nm. Since the conventional UV-curable photosensitive resist ink is one that cures by irradiating with ultraviolet rays of 100 to 380 nm (Printed Circuit Technical Handbook, page 765), this is sufficient.

[0006]

However, the UV-curable solder resist ink has since been improved so that it cures at a wavelength close to visible light. For this reason, it has become necessary to provide the electrical laminate with the ability to absorb ultraviolet rays having a wavelength of 380 to 420 nm.

An object of the present invention is to provide an electrical laminate which does not transmit ultraviolet rays having a wavelength of 380 to 420 nm.

[0008]

As a result of various studies, the present inventors have found that the benzoxazolylthiophene compound represented by the general formula 3 and the pyrazoline compound represented by the general formula 4 are the same as those of the present invention. It was found to be effective for achieving the purpose.

[0009]

[Chemical 3] The substituents R ₁ and R ₂ represent hydrogen, halogen or an alkyl group having 1 to 6 carbon atoms.

[0010]

[Chemical 4] The substituents R ₁ , R ₂ and R ₄ represent hydrogen, an alkyl group having 1 to 6 carbon atoms or a phenyl group (including a halogen or an alkyl nucleus substituent), the substituent R ₃ is a methylene group, an ethylene group,
It represents a propylene group, a carbonyl group or a phenylethylene group.

An example of the benzoxazolylthiophene compound represented by the general formula 3 is 2,5bis (tertiarybutylbenzoxazolyl (2) thiophene.

An example of the pyrazoline compound represented by the general formula 4 is 1- (phenyl) -3- (4
-Tert-butyl-styryl) -5- (4-tert-butylphenyl) -pyrazoline.

The benzoxazolylthiophene compound represented by the general formula 3 and the pyrazoline compound represented by the general formula 4 are used in combination, and one or two kinds of the benzoxazolyl compound and the pyrazoline compound are used, respectively. Of course, there is no problem in using the above.

When the benzoxazolylthiophene compound represented by the general formula 3 and the pyrazoline compound represented by the general formula 4 are further compounded with a coumarin-based compound having an absorption peak at 340 to 360 nm, 420
absorptivity in nm is improved and further 340 to 360 n
m is also preferable because it also absorbs ultraviolet rays.

As the thermosetting resin, any of those used in various electrical laminates can be used, but it is particularly effective in the case of a resin having a good light transmittance such as an epoxy resin.

The base material is not particularly limited as long as it is also used in various electrical laminates, but it is usually a glass woven cloth, a glass non-woven cloth, or a mixed weave of glass fibers and other fibers. Cloth or non-woven fabric is used.

The blending amount of the benzoxazolylthiophene compound or the pyrazoline compound varies depending on the thickness of the laminate. If the thickness of the laminate is large, a small amount is sufficient, and if it is thin, it is increased. For example, in a laminated plate formed by stacking two prepregs obtained by impregnating and drying a glass cloth having a thickness of 0.1 mm with a thermosetting resin (epoxy resin) to obtain a resin content of 43% by weight, the thermosetting resin ( 0.2% to epoxy resin). If the blending amount is too large, the color tone of the laminated plate changes, so it is preferably set to 1% or less.

When the pyrazoline compound and the benzoxazolylthiophene compound or the coumarin compound are used in combination, the mixing ratio is preferably equal. In addition, it is preferable that the combined amount of both is 1% or less.

[0019]

[Function] A base material is impregnated with a thermosetting resin containing a benzoxazolylthiophene compound or a pyrazoline compound,
A laminate obtained by heating and pressing, that is, a laminate having a thermosetting resin as a matrix, is absorbed by these compounds even when irradiated with light of 380 to 420 nm, and affects the resist ink applied on the opposite side. Disappear.

Example 1 1- (phenyl) -3- (4-tert-butylstyryl) -5- (4-tert-butylphenyl) -pyrazoline was added to epoxy resin 100 at 0.2 (weight ratio, The same applies hereinafter) to form a varnish, which is impregnated into a glass cloth having a thickness of 0.1 mm and dried to form a prepreg having a resin content of 43% by weight. Two sheets of this prepreg are stacked, and the thickness is 70μ above and below it.
m copper foils were stacked and heated and pressed at 170 ° C. and 5.0 MPa for 90 minutes to obtain a laminated plate. The copper foil on both sides was removed by etching and the hue was compared to a laminate without 1- (phenyl) -3- (4-tert-butylstyryl) -5- (4-tert-butylphenyl) -pyrazolin. Furthermore, it is 700m with an ultraviolet irradiator (Oak Seisakusho)
Irradiate with UV of J / cm ² and transmit illuminance meter UV-MOI
With two types of sensors, UV-35 (detects ultraviolet rays of 330 to 370 nm) and UV-42 (400 to 440n).
m ultraviolet ray is detected) to determine the transmittance.

Next, liquid resist PSR-
1000 (made by Taiyo Ink) was applied by screen printing and dried at 80 ° C. for 15 minutes. A negative film was placed on one side, the side of the negative film was irradiated with ultraviolet rays and developed with trichloromethane, and it was examined whether or not the resist remained on the side not exposed.

Example 2 1- (Phenyl) -3- (4-tert-butylstyryl) -5- (4-tert-butylphenyl) -pyrazoline and 4-methyl-7-N, N diethylaminocoumarin were combined with an epoxy resin. 0.1 was added to 100 to form a varnish, and a laminated plate was obtained in the same manner as in Example 1, and this laminated plate was also subjected to the same test as in Example 1.

Example 3 1- (Phenyl) -3- (4-tert-butylstyryl) -5- (4-tert-butylphenyl) -pyrazoline and 2,5bis (tert-butylbenzoxazolyl (2 ) 0.1% of thiophene was added to each epoxy resin 100 to form a varnish, and a laminated plate was obtained in the same manner as in Example 1. This laminated plate was also subjected to the same test as in Example 1.

Comparative Example 1 2 Hydroxy-4-methoxybenzophenone was added to epoxy resin 100 in an amount of 1.0, and a laminated plate was obtained in the same manner as in Example 1. This laminated plate was also subjected to the same test as in Example 1. ..

Comparative Example 2 1.0% of 2- (2'-hydroxy 5'methylphenyl) benzothiazole was added to epoxy resin 100, and a laminated plate was obtained in the same manner as in Example 1 below. The same test as in Example 1 was performed. The above test results are shown in Table 1.

[0025]

[Table 1]

[0026]

EFFECTS OF THE INVENTION According to the present invention, when the ultraviolet ray is exposed at a relatively long wavelength of 380 to 420 nm, the resist ink coated on the opposite side is not exposed and the color tone of the laminated plate is not changed. Play.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location H05K 1/05 8727-4E (72) Inventor Tetsuo Eda 1500 Ogawa, Shimodate-shi, Ibaraki Hitachi Chemical Co., Ltd. Shimodate Factory (72) Inventor Yoshiyuki Takeda 1500 Ogawa, Shimodate City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Shimodate Factory

Claims (4)

[Claims] 1. An electrical laminate using a resin containing a benzoxazolylthiophene compound represented by the general formula 1 as a matrix. [Chemical 1] The substituents R ₁ and R ₂ represent hydrogen, halogen or an alkyl group having 1 to 6 carbon atoms. 2. An electrical laminate using a resin containing a pyrazoline compound represented by the general formula 2 as a matrix. [Chemical 2] The substituents R ₁ , R ₂ and R ₄ represent hydrogen, an alkyl group having 1 to 6 carbon atoms or a phenyl group (including a halogen or an alkyl nucleus substituent), the substituent R ₃ is a methylene group, an ethylene group,
It represents a propylene group, a carbonyl group or a phenylethylene group. 3. The electrical laminate according to claim 2, wherein a resin containing a coumarin-based compound in addition to the pyrazoline compound is used as a matrix. 4. An electrical laminate using a resin containing a benzoxazolylthiophene compound represented by the general formula 1 and a pyrazoline compound represented by the general formula 2 as a matrix.