A kind of etching method of silver-copper solder

Abstract

The invention relates to an etching method for silver-copper solder, which comprises the following steps: (1) Alkaline degreasing: put the brazed semi-finished shell into an alkaline degreasing solution for cleaning; (2) Washing: first rinse with tap water, and then Clean it with deionized water; (3) pickling: put the washed shell into the pickling solution to clean; (4) dry; use a high-temperature blast drying box to dry the washed shell at high temperature; (5) ) Etching: Put the casing into the etching solution; (6) After the etching is completed, take out the casing and repeat the process step (2) washing with water, and step (4) drying. Advantages: 1) There is no corrosion damage to the etching of silver-copper solder, and the shell brazing shape, size, solder coverage and subsequent plating reliability are high. 2) Slow down the etching process, increase the range of etching time, 3) reduce environmental pollution; 4) low cost, simple and easy to implement; 5) solve the "silver migration" problem of the RF power device casing, the effect is remarkable.

Description

technical field

[0001] The invention relates to an etching method of silver-copper solder, which belongs to the technical field of surface treatment. Through the method, the silver-copper solder can be selectively removed from all positions of the whole. This method is especially useful for obtaining the desired shell brazing shape, size, solder coverage and subsequent plating reliability. In addition, this method is especially critical as a pre-treatment for products with "silver migration" requirements . Background technique

[0002] Silver-based solder is the longest and most widely used type of solder in solder. Especially the Ag-Cu eutectic (Ag72-Cu28) solder is currently the most widely used solder in the soldering process of electronic packaging devices. It has a low melting point, no crystallization interval, good fluidity, and the thermal conductivity and electrical conductivity of the formed weld Good performance, so in the manufacture of electronic packaging com...