JPH058101B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for manufacturing a laminate for chemical plating which has an extremely excellent effect in preventing the transmission of ultraviolet rays. [Prior art] When processing a chemically plated laminate into a printed wiring board using a well-known additive process, Tokigai Akira's
As explained in detail in No. 59-151495, there are the following steps. A. Drilling holes in a laminate for chemical plating using an NC drill B. Chemical etching of the adhesive surface C. Applying a catalyst for chemical plating to the adhesive surface and all inside the holes D. Applying liquid plating resist to the adhesive surface E. Plating resist Exposure, development, patterning F Chemical plating G Printed wiring board In the above steps, the plating resist enters the hole formed in Step A, and the plating resist enters the hole formed in Step E. The plating resist inside the through-hole is exposed to light and hardened, and during chemical plating in step F, no plating is deposited on the plating resist inside the hole, which may cause poor plating deposition inside the through-hole. The cause and mechanism for this is that the light that has passed through the plating resist layer is refracted by the glass filament of the glass cloth, which is the base material of the chemical plating laminate, and the plating resist on the hole wall is exposed to light and hardened. is possible. [Purpose of the Invention] As a result of extensive research by the present inventors to prevent the hardening resist attached to the hole walls as described above from being exposed to light and hardening, the present inventors have developed a method to prevent UV transmission from being transmitted to the adhesive layer. The present invention has been completed by discovering that the above object can be achieved. [Structure of the Invention] The present invention provides a method for manufacturing a laminate for chemical plating in which an adhesive layer made of a curable resin containing synthetic rubber is formed on both surfaces of a thermosetting resin laminate. 0.1 to 5.0% by weight of an organic ultraviolet absorbing substance exhibiting an absorption peak at 10 nm to 450 nm is blended into the resin of the resin-impregnated base material constituting the surface layer of the laminate,
The method for producing a laminate for scientific plating is further characterized in that 0.1 to 20% by weight of an inorganic oxide having a maximum particle size of 20 μm or less is blended into the adhesive layer. The organic ultraviolet absorbing substances used in the present invention are hydroxybenzophenones and hydroxyphenylbenzotriazoles, such as 2-hydroxy-4octoxybenzophenone and 2-hydroxybenzophenone.
(2'-hydroxy-5'-methylphenyl)-benzotriazole, 2-(2'-hydroxy-3'-t-
Butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-t
-octylphenyl)-benzotriazole, 2
Examples include -(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole. Both of these are 10n
It shows a light absorption peak in the wavelength range of m to 450 nm. Particularly suitable for use in the present invention is 2-(2'-hydroxy-3'-t-butyl-5'-
methylphenyl)-5-chlorobenzotriazole and 2-(3-t-butyl-5-methyl-2-
hydroxyphenyl)-5-chlorobenzotriazole. Inorganic oxides used in the present invention include magnesium oxide, aluminum oxide, iron oxide, titanium oxide, zinc oxide, lead oxide, silicon oxide, and the like. Among these, titanium oxide is suitable for use in the present invention. To explain the manufacturing method of the present invention, the organic ultraviolet absorbing substance described above is dissolved in a commonly used thermosetting resin varnish, and a base material such as a glass woven cloth is impregnated to obtain a thermosetting resin-impregnated base material. This is used as one or more layers as a surface layer, and a thermosetting resin-impregnated base material containing no organic ultraviolet absorbing substance is superimposed as an inner layer, and then heated and pressure molded to obtain a laminate. A laminate for chemical plating having an adhesive layer is obtained by applying an adhesive containing the inorganic oxide to the surface of this laminate and drying it. As described above, since an organic ultraviolet absorbing substance and an inorganic oxide are used in combination, and only an inorganic oxide is mixed in the adhesive layer, the chemically plated laminate obtained according to the present invention can be used after chemically plating. It is possible to exhibit an excellent ultraviolet transmission prevention effect without any adverse effect on the adhesion and soldering heat resistance of the copper film. If the organic ultraviolet absorber exceeds 5.0% by weight, the solvent resistance and heat resistance of the laminate will be poor, and if it is less than 0.1% by weight, the ultraviolet shielding effect will be reduced. In addition, if oxides are added in excess of 20% by weight,
Increased adhesive viscosity and poor plating adhesion in subsequent processes. Furthermore, if the oxide content is less than 0.1% by weight, the UV shielding effect is small. The oxide content is preferably 1.0 to 10% by weight. Regarding the particle size of the oxide, in order to form high-precision fine patterns, if particles of 20 μm or more are present, the oxide particles will be exposed on the adhesive surface during the chemical etching process, causing unevenness in the circuit formed by plating, and causing the circuit to deteriorate. impairs the smoothness of the surface. Oxide particle size is preferably 5μ
m or less. [Effects of the Invention] According to the present invention, ultraviolet rays passing through the plating resist layer are blocked by the adhesive layer and the surface layer of the laminate;
Since it does not penetrate deeply into the layers of chemical plating laminates, it is possible to expose and remove the plating resist that adheres to the hole walls.
Hardening can be prevented. Furthermore, by using a UV absorber and an inorganic oxide in combination, the effect of blocking UV rays is large, and the organic UV absorbing substance is not present on the surface (adhesive layer) of the laminate with an adhesive layer, and its addition Since the amount is small, the electrical properties, chemical properties, and heat resistance of the printed wiring board will not deteriorate. [Example] The method for manufacturing a laminate for chemical plating according to the present invention will be described below using Examples and Comparative Examples.
"Part" represents "part by weight." Example 1 100 parts by weight of Epicote EP-1046 (brominated bisphenol A epoxy resin manufactured by Yuka Shell Co., Ltd.), 4 parts by weight of dicyandiamide, 0.15 parts by weight of 2-ethyl-4-methylimidazole, 2-( as an organic ultraviolet absorbing substance) 2'-Hydroxy-3'-t-butyl-5'-
A varnish solution was obtained by dissolving 2 parts by weight of (methylphenyl)-5-chlorobenzotriazole in a solvent of methyl ethyl ketone and methyl cellosolve to a total solid content of 50% by weight and stirring uniformly. After impregnating a woven glass cloth with this varnish and drying it,
A prepreg (A) with a resin content of 45% was obtained. Further, a prepreg (B) having a resin content of 45% was obtained in the same manner as the above recipe except that no organic ultraviolet absorbing substance was blended. One sheet each of prepreg (A) as both surface layers and six sheets of prepreg (B) as the inner layer were stacked at 165℃.
An epoxy resin laminate was obtained by heat-pressing molding at 60 kg/cm ² for 90 minutes. Next, an adhesive was prepared with the following composition, applied to the epoxy resin laminate described above, and heated at 160°C for 120 minutes to form an adhesive layer on both sides to obtain a laminate for chemical plating. . The thickness of the adhesive layer was 30 μm. NBR rubber (JSR-N-230SH) 100 parts resol type phenolic resin 100 parts SiO ₂ powder (maximum particle size 5 μm) 10 parts TiO ₂ powder (maximum particle size 1 μm) 10 parts methyl ethyl ketone 500 parts Example 2 Same as Example 1 In the process, prepreg (A) and prepreg (B) were obtained, and 2 each of prepreg (A) was used as both surface layers.
This sheet was laminated with four sheets of prepreg (B) as an inner layer, and heated and pressure molded at 165° C. and 60 kg/cm ² for 90 minutes to obtain an epoxy resin laminate. Next, an adhesive was prepared according to the following composition and applied to the epoxy resin laminate described above to obtain a laminate for chemical plating in the same manner as in Example 1. NBR rubber (JSR-N-530) 100 parts Resol type phenolic resin 100 parts TiO ₂ powder (maximum particle size 10 μm) 5 parts Methyl ethyl ketone 500 parts Comparative example 1 Only the prepreg (B) obtained in the process of Example 8
The sheets were stacked together and heated and pressure molded at 165° C. and 60 kg/cm ² for 90 minutes to obtain an epoxy resin laminate. Next, an adhesive was prepared according to the following composition and applied to the epoxy resin laminate described above to obtain a laminate for chemical plating in the same manner as in Example 1. NBR rubber (JSR-N-230SH) 100 parts Resol type phenolic resin 100 parts TiO ₂ powder (maximum particle size 10 μm) 60 parts Methyl ethyl ketone 500 parts Comparative example 2 An adhesive was prepared with the following composition, and the adhesive obtained in Example 2 was prepared. The mixture was applied to an epoxy resin laminate to obtain a chemically plated laminate in the same manner as in Example 1. NBR rubber (JSR-N-230SH) 100 parts Resol type phenolic resin 100 parts Methyl ethyl ketone 500 parts Comparative example 3 Prepare an adhesive with the same composition as in Comparative example 2 and apply it to the epoxy resin laminate obtained in Comparative example 1. Then, in the same manner as in Example 1, a laminate for chemical plating was obtained. The chemically plated laminates obtained in Examples 1 and 2 and Comparative Examples 1, 2, and 3 were processed in the order of steps A to G to obtain printed wiring boards.

[Table] Table 1 shows the evaluation results of the above printed wiring board. In Examples 1 and 2, there were no defects due to plating precipitation in the through holes, no blistering occurred in the plated copper film, and the soldering heat resistance of the printed wiring board was good. On the other hand, in Comparative Example 1, no defects due to plating precipitation in the through holes occurred, but blistering of the plating copper film occurred. In Comparative Example 2, defects due to plating precipitation were observed in the through holes. In Comparative Example 3, defects due to plating precipitation within the through holes occurred significantly.

Claims (1)

[Claims] 1. In a method for manufacturing a laminate for chemical plating in which an adhesive layer made of a curable resin containing synthetic rubber is formed on both surfaces of a thermosetting resin laminate, the surface layer of the thermosetting resin laminate is formed. 0.1 to 5.0% by weight of an organic ultraviolet absorbing substance exhibiting an absorption peak at 10 nm to 450 nm is blended into the resin of the resin-impregnated base material, and 0.1 to 20% of an inorganic oxide with a maximum particle size of 20 μm or less is added to the adhesive layer. A method for manufacturing a laminate for chemical plating, characterized in that a laminate is mixed by weight%.