A copper-reducing etching solution for printed circuit boards

Abstract

The invention discloses copper reduction etching liquid for printed circuit boards. The copper reduction etching liquid comprises the following raw materials by weight parts: 3.0-15.0 parts of hydrogen peroxide, 3.5-12.0 parts of sulfuric acid, 1.0-5.0 parts of D-pentose, 0.1-1.0 part of a copper corrosion inhibitor and 68.0-86.7 parts of de-ionized water. According to the copper reduction etching liquid, hydrogen peroxide and sulfuric acid react with copper to form water-soluble copper sulfate so as to thin a copper layer; D-pentose can be used for increasing the etching speed in the horizontal direction of the copper surface and inhibiting the etching speed in the vertical direction of the copper surface, so that etching is carried out in the horizontal direction of the copper surface as far as possible and the influence on the etching rate caused by different crystals on the copper surface is reduced; the copper corrosion inhibitor can be used for protecting the copper surface, so that the etched copper surface is kept bright; the manufacturing time of the printed circuit boards is effectively shortened, and the manufacturing cost is reduced.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a copper-reducing etching solution for printed circuit boards. Background technique [0002] At present, in the manufacturing process of printed circuit boards (PCBs), sometimes the copper layer on the board surface is too thick after electroplating with a hole-filling solution, and it is necessary to thin the copper layer to improve the yield of subsequent graphics. However, due to the presence of small air bubbles on the surface of the circuit board during the electroplating process, some small areas of loose copper crystals are included in the electroplated copper layer. The appearance of this loose structure is consistent with the normal structure. However, when the copper layer is thinned, the copper in these tiny areas is quickly etched by the potion, and the copper etching speed in other areas is normal, forming needle-shaped depressions on the copper surface, commonly kno...

AI Technical Summary

Problems solved by technology

In this way, the amount of thinning the copper layer will be reduced each time, about half of the original, which can greatly reduce the number of pinholes, but one electroplating and one copper reduction process will be added, which will take a long time and increase the cost

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