JPH05214548A - Adhesive for additive plating - Google Patents

Abstract

PURPOSE:To improve the solder heat resistance and surface roughness of the adhesive when a microcircuitry pattern is formed by incorporating a superfine- particle silica preheated along with an acrylonitrile-butadiene rubber and a resol-type phenol resin into the adhesive. CONSTITUTION:An acrylonitrile-butadiene rubber contg. 25-50% acrylonitrile, a resol-type phenol resin and the superfine-particle silica as the inorg. filler preheated to 130-180oC are incorporated as the essential components to constitute an adhesive for additive plating. The diameter of the silica particle is controlled to about 0.01-10mum and the specific surface to about 50-400mg/g. A microcircuitry pattern is easily formed by using this adhesive, and a metallic plating film excellent in solder heat resistance is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive provided on an additive-plated substrate suitable for a chemical copper plating bath,
The present invention relates to an adhesive for chemical copper plating suitable for forming an ultrafine circuit pattern.

[0002]

2. Description of the Related Art Generally, a laminated plate for additive plating is used which has a surface coated with an adhesive layer of synthetic rubber and thermosetting resin having a thickness of 20 to 50 μm. This adhesive is chemically or physically roughened and then subjected to chemical copper plating to secure the adhesion between the chemical copper metal coating and the base adhesive layer.

However, the surface formed by roughening the adhesive surface is rough, and the formation of a fine circuit pattern, which is characteristic of the additive plating substrate, is restricted.

Recently, more severe processing conditions and processing conditions are required, there is no blistering during plating, sufficient adhesion at high temperature applied during soldering, stabilization of adhesive, and rough etching after etching. High quality characteristics for the purpose of forming an ultrafine circuit pattern, such as reduction in degree and suppression of powder falling after roughening, are required, but a satisfactory composition has not yet been found.

[0005]

The object of the present invention is to study further for the purpose of obtaining higher quality characteristics, and as a result, no blistering of plated copper occurs, and adhesion and solder heat resistance are excellent, and An object of the present invention is to provide an adhesive for additive plating, which is also extremely excellent in surface roughness, which is an important point when forming a fine circuit pattern.

[0006]

In order to achieve the above object, the present invention uses an adhesive for adhesive plating having the following composition. That is, it is an adhesive consisting of acrylonitrile-butadiene rubber (hereinafter referred to as NBR), a resol-type phenol resin, and ultrafine silica particles preliminarily dried at 130 to 180 ° C. as an inorganic filler. An agent is obtained, which is applied to a substrate for additive plating, and integrated under heating and pressure. The compounding ratio of the adhesive of the present invention is preferably as follows. NBR 30 to 70% by weight Resol type phenolic resin 20 to 60% by weight Silica 0.1 to 10% by weight

[0007]

As the NBR, a high acrylonitrile butadiene rubber having a nitrile content of 25% or more is preferable. The reason is that it can withstand an organic solvent, a strong acid and a strong alkali in the plating process, and a nitrile content of 25 to 50% is particularly preferable. The adhesive-coated laminate coated with these adhesives is often subjected to surface roughening and plating pretreatment before entering the chemical copper plating. Since NBR is weak with respect to the roughening liquid, if the NBR component is 70% or more, the roughening speed becomes fast, and the appearance and roughness of the roughened surface become uneven. On the other hand, if it is 30% or less, the roughening time becomes long and the peel strength after plating is lowered.

The phenol resin is a resol type which has good compatibility and reactivity with NBR, but oil-modified resole and alkylphenol-modified resole can also be used. The modification rate is preferably 10 to 15% for oil modification and 5 to 30% for alkylphenol modification. When the phenol resin component is 60% or more in the adhesive compounding ratio, the solder heat resistance is good, but the peel strength is lowered because the NBR component is relatively small. Considering the electrical characteristics, the maximum amount of phenolic resin is about 60%, while if it is less than 20%, the solder heat resistance is lowered.

The main purpose of adding the inorganic filler is to improve the peel strength, but the effect cannot be expected sufficiently even if the compounding ratio is large or small, and the ratio is preferably 0.1 to 10%. Examples of the inorganic filler include ultrafine particle silica, alumina, talc, calcium carbonate, titanium oxide and the like. In the present invention, ultrafine particle silica preheated at 130 to 180 ° C. is particularly preferably used. The reason is that by removing the water contained in the ultrafine silica, the secondary aggregation of the particles is reduced, the dispersion in the adhesive is improved, and the solder heat resistance is further improved. Also, the smaller the particle size, the better, 0.01 to 10 μm,
Those having a specific surface area of 50 to 400 mg / g are effective for achieving the object of the present invention.

[0010]

Example An adhesive for additive plating was prepared according to the formulation shown in Table 1.

[0011]

[Table 1]

The respective examples and comparative examples were mixed under the same conditions, and the ratio of the phenol resin was 100: 50, 10.
It is set to 0: 100. These adhesives were applied to have an average thickness of about 20 μm and dried to obtain a substrate for additive plating. The surface of this substrate was chemically roughened, subjected to chemical copper plating, and then evaluated as a copper-clad laminate. The results are as shown in Table 1. In the examples, the surface roughness is extremely excellent, the plating property is good, and the solder heat resistance is also excellent. This is because the substrate surface is not smooth like a mirror plate and has fine irregularities, and it is considered that the anchoring effect of plated copper is not lost.

Comparing the examples and the comparative examples, the peel strength by using preheated ultrafine silica particles,
It is sufficiently effective in improving solder heat resistance. Moreover, since the surface roughness is also very good, the use of the adhesive obtained by the present invention makes it possible to easily form an ultrafine circuit pattern, which was difficult with the conventional adhesive. is there.

[0014]

The adhesive for additive plating of the present invention contains NBR, a resole-type phenol resin, and preheated ultrafine particle silica. Therefore, it is easy to form a fine circuit pattern, and solder heat resistance. An excellent metal plating film can be obtained.

Claims (1)

[Claims] 1. An adhesive for additive plating which contains, as essential components, an acrylonitrile amount of 25 to 50% acrylonitrile-butadiene rubber, a resol-type phenol resin, and ultrafine silica particles preheated at 130 to 180 ° C. as an inorganic filler.