SU539926A1 - PCB paint - Google Patents

Description

one

The invention relates to printing inks, in particular to protective galvanized paints of screen printing, intended for the manufacture of printed circuit boards with positive and negative results, and in the field of radio industry, the device, electronic and engineering industries.

A known protective galvanic paint screen printing for the manufacture of printed circuit boards based on polyurethane resin, resistant to herbal solutions.

The closest in technical essence is the paint composition, which includes cyclo-rubber, chloroparaffin, silicone fluid, transformer oil, paraffin, aerosil, barium sulfate, aluminum stearate, surfactant, pigment and solvents.

However, these paints have poor adhesion to the substrate, so under the action of the electrolyte plating, the adhesion of the colorful plaster E to the copper foil is reduced to 3-4 points (the lattice method, GOST 15140-69 When:

leads to deterioration of galvanic resistance of paint.

Reduction of adhesion in time and in the process of electroplating makes it difficult or impossible to correct the pattern and intermediate degreasing, as well as store the sealed boards for more than 5 days. In addition, paint is unstable in tin-nickel electrolytes and nitrate gilding. When printing through high-density nets (Kapron Grid No. 110-130, stainless wire 004), it forms a layer of insufficient thickness (less than 15 km, which also leads to a decrease in galvanic resistance.

The aim of the invention is to increase the adhesion of paint to copper and its resistance to the environment galvanized with a pH of 0.2-10.

The goal is achieved by the fact that the ink for printed circuit boards containing cyclo-rubber, chloroparaffin, polymethylsiloxane LIQUID; transformer oil, paraffin, aerosil, barium sulfate, aluminum stearate, surfactant, pigment and solvent, additionally contains cyclopentadiene oil. With

This component is taken in the following COOTV situation, weight.h:

Cyclocoupler19,35-25,85

Cyclopentadienic

oil5.0 - 20.0

Barium sulfate 23,66-33,64

Chloroparafin5.0 - 7.0

Pigment 0.5 - 1.5

PAV0,14-0,16

Aerosil 1,5-2,5

Paraffin0,2-0,6

Aluminum stearate OD-0,3

Transformer maslo0,2-O, 6

Polymethylsiloxane fluid1.0-3.0

Solvents19,8-29,7

With the introduction of cyclopentadiene oil into a binder consisting of a solution of cyclochue, the adhesion of the colorful film to the copper foil is kept within 1-2 points (maximum value) during 10-15 days, as well as after exposure to copper electrolyte. In this way, the shelf life of sealed boards is prolonged, during which the pattern can be adjusted, degreased and galvanized. In addition, cyclopentane oil increases the galvanic resistance of the paint, as a result of which galling is absent or very small. The paint is resistant to electrolytes tin-nickel and gilding.

With about with and in 1, weight.h .:

Cycloacoup25.85

Tetralin20,0

Benzyl alcohol5.0

Cyclopentadiene oil 5.0

Barium sulphate 23.66

Chloroparaffin7.0

Phthalocyanine blue pigment1, 5

Alcamon OS-20,16

Aerosil2,5

Paraffin0,6

Aluminum stearate 0.3

Transformer oil0,6

Polymethylsilane oksanov liquid

About about 2 days, parts:

Cyclocoupler 22,5

Tetraline19.5

Benzyl alcohol4,5

Cyclopentadiene Oil10

Barium sulphate 31

Phthalocyanine blue pigment1

Alcamone OS-20,15

Aerosil2

Paraffin0,4

Aluminum stearate 0,2

Transformer oil0,4 Polymethylsiloxane liquid2

Chloroparaffins

Composition 3, parts by weight: Shsklokauchuk19,35

Tetralin14,8

Benzyl alcohol3,7

Cyclopentadiene oil 20,0

Baran sulphate33,64

Chloroparaffin5, O

Blue phthalocyanine pigment 0, 5

Surfactant

Alcamon OS-20,14

Aerosil1,5

Paraffin 0,2

Aluminum stearate 0.1

Transformer oil0,2

P olimethylsiloxane liquid1,0

The table shows the comparative figures of the known and proposed inks.

As can be seen from the table, the developed ink exceeds the known ink in printing properties, in terms of adhesion to guilded foil, in thickness of the ink layer on copper foil when printed through low and high thickness sieves, in galvanized resistance. It allows you to get high, positively printed PCBs that are thin off the thin elements.

A protective electroplated paint is applied through a stencil form to the prepared surface of copper-foiled getinax, then the conductors are expanded in an unprotected pattern in copper electrolytes, tin-lead, silver, tin-nickel, gilding and others, remove the protective paint layer with a solvent and etch the foil with the appropriate herbs shchim solution. The paint serves as a temporary protection for copper foil from electroslites with a pH of 0.2-10.

The paint is prepared according to the following technology. Pre-receive lacquer (solution cyclokauchuk). The rubber block, which is a solid lumpy resin, is dissolved in a mixture of tetralin and benzyl alcohol in a dissolver for 5-6 hours at room temperature. Next, the mixture is prepared in a vertical kneading mask by mixing all the components taken in the indicated ratios, and it is ground on a 3 - roller paintbrush machine and the milling is no more than 15 microns.