CS260595B1 - Means for creating a layer of protection at etched print joints - Google Patents

Abstract

The solution relates to a composition for forming a protective layer during etching of printed circuits, which consists of 0.10 to 30.00 parts by weight of a dye and/or pigment, 0.50 to 20.00 parts by weight of an organic, aliphatic, monocarboxylic hydroxy acid with 2 to 20 carbon atoms in the molecule, or a mixture of these acids, 1.00 to 60.00 parts by weight of rosin and/or rosin-based resin, and the remainder up to 100.00 parts by weight is formed by an organic solvent with a boiling point in the range of 50 to 270 °C.

Description

BACKGROUND OF THE INVENTION The present invention relates to a printed circuit board which is intended to form a protective layer in an etching process.

It is a method of manufacturing printed circuit boards in which a thin, conductive, most commonly copper layer is applied over the entire non-conductive base material. The portion of the conductive layer that is intended to form the bond is covered with a protective layer, the surrounding, uncovered portion of the conductive layer is etched off, and the portion of the conductive layer determined for the function of the bond remains.

Up to now, the protective layer has been formed by photochemical application of acetone, nitrocellulose or other similar dyes, or by means of special markers or markers.

The use of the photochemical route is a demanding technique, other known methods are very laborious and do not guarantee the formation of a perfect protective layer. The underlay occurs and the layer breaks. Before soldering it is necessary to remove the created protective layer and soldering means to use soldering means.

The etching of the printed circuit board according to the invention consists of 0.10 to 30.00 parts by weight of dye and / or pigment, 0.50 to 20.00 parts by weight. % of an organic, aliphatic, monocarboxylic hydroxy of 2 to 20 carbon atoms in the molecule, or a mixture of these acids, 1.00 to 60.00 wt. parts of rosin and / or rosin-based resin and the remainder up to 100.00 wt. The parts consist of an organic solvent with a boiling point in the range of 50 to 270 ° C.

As regards the organic solvent, paraffinic hydrocarbons or mixtures thereof and / or cycloparaffinic hydrocarbons or mixtures thereof and / or aromatic hydrocarbons or mixtures thereof and / or aliphatic halogenated hydrocarbons or mixtures thereof and / or aromatic halogenated hydrocarbons or mixtures thereof and / or or alcohols or mixtures thereof and / or ethers or mixtures thereof and / or ketones or mixtures thereof and / or esters or mixtures thereof and / or nitrated aliphatic hydrocarbons or mixtures thereof and / or nitrated aromatic hydrocarbons or mixtures and / or amides thereof or mixtures.

The rosin and / or rosin-based resins may further be combined with any natural and / or synthetic resin, whereby, for example, the resilience, chemical resistance, adhesion of the formed protective layer to the substrate and, of course, also the solubility of the resin in the solvent used.

The invention provides an even, compact and uninterrupted protective layer having high chemical resistance to the etching means used. It is ensured the creation of a perfect printed circuit, which further has very good solderability.

Modern writing, drawing and drawing means can be used to form the protective layer, in particular technical pens. This makes it possible to produce all types of printed circuit boards, that is to say both printed circuit boards for integrated circuits, and printed circuit boards produced by the dividing line method, in which the entire areas of the patterns are isolated.

The invention is illustrated by the following examples.

Example 1 xanthene dye glycerin L-hydroxypropanoic acid colophony butyl alcohol

1.00

6.50

6.50

20,00

66.00 wt.

wt.

wt.

wt.

wt.

parts parts parts parts parts

This composition is suitable for the formation of a protective layer in the manufacture of fine printed circuits, which are primarily intended for integrated circuits. The use of a technical tubular pen with a tube diameter of 0.18 mm and 0.25 mm has proven suitable for application. The conductive layer was etched off in a saturated ferric chloride solution.

Example 2 carbon black hydroxyethanoic acid resin based on mixed glycerin ester and resin acids contained in rosin copolymer vinyl chloride vinyl acetate butyl acetate

7.50 wt. parts 0.50 wt. parts

15.00 wt. parts 7.50 wt. parts

69.50 wt. parts

This composition is suitable for the formation of a protective layer in the production of printed circuits with a conductive path of 2 to 3 mm, which are intended especially for power circuits. For application, a technical tubular pen with a tube diameter of 1.0 to 1.4 mm has proved to be suitable. The etching can then be carried out in a 10% hydrochloric acid solution with the addition of hydrogen peroxide to 10% by volume.

Example 3 Azine dye 30.00 wt. parts 10 hydroxyeicosanoic acid 4.00 wt. parts rosin 5.00 wt. parts by weight of a resin based on a mixed ester of pentaerythritol and resin acids contained in rosin 5.00 wt. parts white spirit 56.00 wt. parts

This composition is suitable for the formation of a protective layer in the manufacture of printed circuits with a conductive path of about 1 mm, which have the widest use in amateur practice with conventional semiconductor devices. The technical pen with a tube diameter of 0.5 to 0.7 mm has proven to be suitable for application. The etching is carried out either in a saturated ferric chloride solution or in ferric chloride etching agents.

Example 4 Isoindoline-based pigment 5.00 wt. parts of 4-hydroxynonanoic acid 0.50 wt. 60 parts by weight of resin based on the resin adduct contained in the rosin. parts xylene 34.50 wt. parts

The composition is suitable for forming a protective layer in the manufacture of printed circuit boards having a conductive path of 1 to 3 mm wide, or for making printed circuit boards by separating lines to protect the conductive layer throughout the images. The funnel pens No. 5 to 10 have proven to be suitable for application. In this case, the etching is suitable in an alkaline etching agent based on ammonia.

Example 5

xanthene dye 1.00 wt. part L-hydroxypropanoic acid 4.50 wt. part rosin 4.50 wt. part propylalkohol 15.00 wt. parts Butyl alcohol 40.00 wt. parts

This composition is suitable for the formation of a protective layer in the manufacture of printed circuit boards by means of the dividing line method, i. by covering the copper foil throughout the patterns and then etching in 10% hydrochloric acid 8 by adding hydrogen peroxide to 10 volume percent.

Claims (1)

SUMMARY OF THE INVENTION An etching agent for the printed circuit board, characterized in that it consists of 0.10 to 30.00 parts by weight of a dye and / or pigment, 0.50 to 20.00 parts by weight of an organic, aliphatic, monocarboxylic hydroxy acid having from 2 to 20 parts by weight. carbon atoms in the molecule, or mixtures of these acids, 1.00 to 60.00 parts by weight of rosin and / or rosin-based resin, and the remainder up to 100.00 parts by weight consists of an organic solvent boiling in the range of 50 to 270 ° C.