JPS6026669A - Resist ink for electroless plating - Google Patents

Abstract

PURPOSE:To provide resist ink for electroless plating which prevent copper release and has high reliability by consisting the name of an epoxy resin compsn. contg. a filler mixed with aluminum silicate having a prescribed grain size or below, a solid soln. of titanium oxide, nickel oxide and antimony oxide and ultrafine grain silica. CONSTITUTION:This resist ink is constituted of an epoxy resin compn. contg. a filler mixed with aluminum silicate having <=15mu grain size, a solid soln. of the above-described oxides and fine grain silica. More specification, the manufacture of a printed wiring board is accomplished by coating an adhesive agent contg. a platng catalyst such as Pd on a base plate such as a paper-phenolic resin laminate contg. a plating catalyst such as Pd then printing the above- described ink for resist thereon. Since the ink for resist has extremely fine particles, the ruggedness on the printed surface is small. Therefore if the surface is thereafter subjected to an electroless plating treatment, copper is hardly stickable to the surface of the resist ink and particularly the solid soln. and the ultrafine grain silica have the effect of making difficult the growth of copper particles sticking to the surface. The generation of copper release and the short circuiting defect occurring therefrom are thus suppressed.

Description

[Detailed description of the invention] The present invention relates to an ink for electroless plating.

As the devices in which printed wiring boards are incorporated become smaller, there has been a need for printed wiring boards that can be mounted with high density, and there has been a need for narrower spacing between lines.

By the way, a fully additive type printed wiring board in which a circuit is provided by metal plating only the necessary circuit parts by electroless plating is produced by, for example, applying a plating catalyst-containing adhesive to a plating catalyst-containing substrate, plating resist printing, It is manufactured by sequentially performing chemical roughening, cleaning, electroless plating, and solder resist printing. When electroless plating is performed, metal tends to adhere to conventional plating resists, and the growth of the metal causes short circuits between lines. This is generally referred to as copper tinting, and as the density of printed wiring boards becomes higher, the number of defects due to copper tinting increases. For this reason, after the electroless plating process, copper flakes are removed by puff polishing or the like, but even with such operations, the copper flakes cannot be completely removed and the work is difficult.

The object of the present invention is to provide a resist ink for electroless plating that can improve the above-mentioned drawbacks, prevent copper tinting, and produce printed wiring boards that are highly reliable and easy to manufacture.

In order to achieve the above object, the present invention has a particle size of 15 μm.
The present invention provides a resist ink for electroless plating characterized by comprising an epoxy resin composition containing the following filler mixed with aluminum silicate, a solid solution of titanium oxide, nickel oxide, and antimony oxide, and ultrafine silica. .

That is, when manufacturing a printed wiring board, after applying an adhesive containing a plating catalyst such as Pd to a substrate such as a paper phenolic resin laminate or a paper epoxy resin laminate containing a plating catalyst such as Pd, the adhesive according to the present invention is applied. Print resist ink for electroless plating. This resist ink for electroless plating is made of an epoxy resin composition, and the filler is aluminum silicate with a particle size of 25μ or less and a solid solution or ultrafine silica with a smaller particle size. 1=
Surface irregularities are small. Therefore, when electroless plating is performed afterwards, it is difficult for copper to adhere to the surface of the resist ink. In particular, the solid solution and ultrafine silica have the effect of making it difficult for the attached copper particles to grow. This suppresses the occurrence of blurring and the resulting short circuit defects. Such effects are particularly noticeable when the total amount of the solid solution and ultrafine silica is 3 parts by weight or more based on 100 parts by weight of the resin. However, if the total amount exceeds 15 parts by weight, it is undesirable because it becomes easy to dissolve in the electroless copper plating solution and contaminates the plating solution.

In addition, the content of filler in the epoxy resin composition is 10
~30% by weight is preferred, less than 10% by weight or 30% by weight
If the number is more than 100%, the printability will be poor, and a predetermined thickness may not be obtained, or the ink may easily protrude beyond a predetermined width.

For example, as a resist ink for electroless plating, 100 parts by weight of epoxy resin and Modaflow 3 as a flow control agent are used.
parts by weight, 17 parts by weight of Ebiform as a hardening agent and 30 parts by weight of butylcarpitol, maximum particle size 15μ
Aluminum silicate 18 below! ! 1 part by weight of titanium oxide, nickel oxide, 8 parts by weight of a solid solution of nickel oxide, and 4 parts by weight of ultrafine particle silica, and 23 m of aluminum silicate in the above composition.
Example 2 of the present invention, in which the solid solution was 3 parts by weight, the ultrafine silica was 4 parts by weight, and the aluminum silicate was 14 parts by weight,
Example 3 of the present invention using 8 parts by weight of solid solution and 6 parts by weight of ultrafine particle silica, 28 parts by weight of aluminum silicate with a maximum particle size of more than 15μ, O weight part of solid solution, and 2 parts by weight of ultrafine particle silica. Using the conventional example, printability, chemical roughening liquid resistance, printed wiring board with copper plating after printing on the board and then chemical roughening and electroless plating treatment were evaluated.
When the growth rate of copper plating and the amount of copper 15"l (the number of copper particles visible under a 20x microscope) were measured, the results shown in the table were obtained. In other words, the copper plating of the present invention was better than that of the conventional example. It is clear that the amount is much lower and the printability is also better.

As shown in the table above, according to the present invention, the resist ink for electroless plating can significantly reduce the amount of copper dust generated during the manufacturing of printed wiring boards, improve the reliability of printed wiring boards, and facilitate the manufacturing thereof. is obtained.

Patent applicant: Hitachi Capacitor Co., Ltd.

Claims (1)

[Claims] (+) In the ink for the resist 1 for electroless plating, aluminum silicate and titanium oxide having a particle size of 15 μm or less,
A resist ink for electroless plating comprising an epoxy resin composition containing a filler mixed with a solid solution of nickel oxide and antimony oxide and ultrafine silica particles. (2) The total amount of solid solution of titanium oxide, nickel oxide, and antimony oxide and ultrafine silica is resin 1"00!I
'! The resist ink for electroless plating according to claim 1, wherein the amount is 3 to 15 parts by weight based on parts ffi. (3) The resist ink for electroless plating according to claims 1 and 2, wherein the filler content is 10 to 30 parts.