JP2946919B2 - Electric laminate - Google Patents

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 an ultraviolet-curable resist ink. In the present invention, a laminate refers to a laminate obtained by impregnating a thermosetting resin into a substrate and heating and pressing, that is, a laminate using a thermosetting resin as a matrix, and attaching a metal foil to one or both surfaces. Also includes metal foil-clad laminates.

[0002]

2. Description of the Related Art In recent years, the wiring density of printed wiring boards has increased, and solder resist printing has been increasingly performed using photosensitive resist ink rather than screen printing.

An ultraviolet-curable photosensitive resist ink is cured by irradiating ultraviolet rays. However, the irradiated ultraviolet light may pass through the laminate, 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 a predetermined pattern is formed on the opposite surface. Cannot be formed.

[0004] When the irradiation amount is reduced, the curing of the resist ink becomes insufficient, and the wear resistance, solvent resistance and moisture resistance are impaired. Therefore, conventionally, an additive type ultraviolet absorber such as a benzophenone-based, benzotriazole-based, or coumarin-based has been blended in the resin.

[0005] These ultraviolet absorbers absorb only ultraviolet light 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 a peak of 340 to 290 nm.
There is an absorption peak near 360 nm. The conventional UV-curable photosensitive resist ink was cured by irradiating ultraviolet rays of 100 to 380 nm (Printed Circuit Technology Handbook, p. 765), which was sufficient.

[0006]

However, the ultraviolet-curable solder resist ink has been improved thereafter, and has been cured at a wavelength close to visible light. For this reason, it has been necessary to provide the electrical laminate with a performance of absorbing ultraviolet light having a wavelength of 380 to 420 nm.

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

[0008]

As a result of various studies, the present inventors have found that a benzoxazolylthiophene compound represented by the general formula (3) and a pyrazoline compound represented by the general formula (4) are used in the present invention. It was found that it was effective to achieve the purpose.

[0009]

Embedded image The substituents R ₁ and R ₂ represent hydrogen, halogen or an alkyl group having 1 to 6 carbon atoms.

[0010]

Embedded image 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 alkyl nucleus substituent), and the substituent R ₃ represents a methylene group, an ethylene group,
Represents a propylene group, a carbonyl group or a phenylethylene group.

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

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

A combination of a benzoxazolyl thiophene compound represented by the general formula (3) and a pyrazoline compound represented by the general formula (4), one or two types of the benzoxazolyl compound and the pyrazoline compound, respectively. Use of the above is, of course, acceptable.

When the benzoxazolylthiophene compound represented by the general formula (3) and the pyrazoline compound represented by the general formula (4) are further blended with a coumarin-based compound having an absorption peak at 340 to 360 nm, 420
The absorption capacity in nm is improved, and 340-360n
m is also preferred.

As the thermosetting resin, any resin can be used as long as it is used for various electric laminates, and it is particularly effective in the case of a resin having a high light transmittance such as an epoxy resin.

The substrate is not particularly limited as long as it is also used for various electric laminates. Usually, it is a glass woven fabric, a glass nonwoven fabric, or a mixed woven fabric of glass fibers and other fibers. Cloth or non-woven fabric is used.

The amount of the benzoxazolylthiophene compound or pyrazoline compound varies depending on the thickness of the laminate. When the thickness of the laminate is large, a small amount is sufficient, and when the thickness is small, it is large. For example, in a laminated plate formed by laminating two prepregs obtained by impregnating and drying a thermosetting resin (epoxy resin) into a glass cloth having a thickness of 0.1 mm to obtain a resin content of 43% by weight, the thermosetting resin ( 0.2% based on epoxy resin). If the compounding amount is too large, the color tone of the laminate will change, so it is preferably 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. It is preferable that the content of both components is 1% or less.

[0019]

The substrate 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 using 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. Disappears.

【Example】

Example 1 1- (phenyl) -3- (4-tert-butylstyryl) -5- (4-tert-butylphenyl) -pyrazoline was added at 0.2 (weight ratio, hereinafter the same) to epoxy resin 100. The varnish was impregnated and dried in a glass cloth having a thickness of 0.1 mm to obtain a prepreg having a resin content of 43% by weight. Two layers of this prepreg are stacked, and a thickness of 70 μ
m of copper foil was stacked and heated and pressed at 170 ° C. and 5.0 MPa for 90 minutes to obtain a laminate. The copper foil on both sides was removed by etching, and the hue was compared with that of a laminate not containing 1- (phenyl) -3- (4-tert-butylstyryl) -5- (4-tert-butylphenyl) -pyrazoline. 700m with UV irradiator (Oak Seisakusho)
J / cm ² UV irradiation, UV-MOI transmission illuminometer
And two types of sensors, UV-35 (detects ultraviolet rays of 330 to 370 nm) and UV-42 (400 to 440 n).
m is detected, and the transmittance is determined.

Next, a liquid resist PSR-
1000 (manufactured by Taiyo Ink) was applied by screen printing and dried at 80 ° C. for 15 minutes. A negative film was placed on one side, and the negative film side was irradiated with ultraviolet rays, developed with trichloromethane, and examined to see if a resist remained on the unexposed side.

Example 2 1- (phenyl) -3- (4-tert-butylstyryl) -5- (4-tert-butylphenyl) -pyrazoline and 4-methyl-7-N, N-diethylaminocoumarin were added to an epoxy resin. A varnish was prepared by adding 0.1 to 100, respectively, to obtain a varnish. A laminate was obtained in the same manner as in Example 1, and the same test as in Example 1 was performed on this laminate.

Example 3 1- (Phenyl) -3- (4-tert-butylstyryl) -5- (4-tert-butylphenyl) -pyrazoline and 2,5 bis (tert-butylbenzoxazolyl (2 ) Thiophene was added to the epoxy resin 100 at a ratio of 0.1 to each varnish. A varnish was obtained in the same manner as in Example 1, and the same test as in Example 1 was performed on this laminate.

COMPARATIVE EXAMPLE 1 1.0 of 2-hydroxy-4-methoxybenzophenone was added to 100 of the epoxy resin, and a laminate was obtained in the same manner as in Example 1. The same test as in Example 1 was performed on this laminate. .

Comparative Example 2 2- (2'-Hydroxy5'methylphenyl) benzothiazole was added to epoxy resin 100 in an amount of 1.0, and a laminate was obtained in the same manner as in Example 1; The same test as in Example 1 was performed. Table 1 shows the test results.

[0025]

[Table 1]

[0026]

According to the present invention, when ultraviolet rays are exposed at a relatively long wavelength of 380 to 420 nm, the resist ink applied on the opposite side is not exposed, and the color tone of the laminate does not change. To play.

──────────────────────────────────────────────────の Continued on front page (72) Inventor Tetsuo Eda 1500 Ogawa Ogawa, Shimodate City, Ibaraki Prefecture Inside the Shimodate Plant, Hitachi Chemical Co., Ltd. (72) Yoshiyuki Takeda 1500 Ogawa Ogawa Shimodate City, Ibaraki Prefecture (56) References JP-A-62-162535 (JP, A) JP-A-3-262185 (JP, A) JP-A-57-35850 (JP, A) JP-A-55-75405 (JP) JP, A) JP-A-62-262052 (JP, A) JP-B-45-37376 (JP, B1) US Patent 3,157,762 (US, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B32B 1/00-35/00 C08K 5/3445-5/3447 C08K 5/45-5/47 H05K 1/00-1/18

Claims (4)

(57) [Claims] 1. An electric laminate comprising a resin containing a benzoxazolylthiophene compound represented by the general formula 1 as a matrix. Embedded image The substituents R ₁ and R ₂ represent hydrogen, halogen or an alkyl group having 1 to 6 carbon atoms. 2. An electric laminate comprising, as a matrix, a resin containing a pyrazoline compound represented by the general formula (2). Embedded image 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 alkyl nucleus substituent), and the substituent R ₃ represents a methylene group, an ethylene group,
Represents a propylene group, a carbonyl group or a phenylethylene group. 3. The electric laminate according to claim 2, wherein the matrix is a resin in which a coumarin compound is added in addition to the pyrazoline compound. 4. A compound according to claim 1 (general formalized 1) benzoxazolyl thiophene compounds and billing represented
Item 2. An electric laminate comprising a matrix containing a resin containing a pyrazoline compound represented by the compound according to item 2 (general formula 2) .