Metal scavenger composition and method for producing the same

Abstract

The invention discloses a metal-removing agent combination for removing pure tin, tin-lead or tin-copper alloy on printed circuit boards and a production method for the metal-removing agent combination, which comprises by weight the following components: iron nitrate 15.9-16.3%, urea 0.3-0.4%, benzotriazole 0.3-0.4%, methyl benzotriazole 0.2-0.3%, hydrochloric acid 1.5-1.7%, nitric acid 33-36%, and the remainder water. The method for producing the removing agent combination comprises such procedures as (1) adding in sequence according to proportion the raw materials nitric acid, iron nitrate, hydrochloric acid, urea, benzotriazole, methyl benzotriazole and water in a production tank; (2) agitating till the raw materials solve completely, and inspecting. The metal-removing agent combination is a standalone fluid, can erode rapidly any foreign matters on a copper surface while maintaining a very low eroding rate to the copper, contains no fluoride and will not erode the base material, has a high removing speed, low environmental pollution, and is of a wide applicability and operation convenience.

Description

technical field [0001] The invention relates to a chemical metal scavenger, more precisely to a metal scavenger composition used in the production process of a printed circuit board to remove pure tin, tin-lead or tin-copper alloy formed on the surface of a substrate and a production method thereof. Background technique [0002] A general printed circuit board has a copper conductor pattern on an insulating base plate, and tin or solder is usually coated on the copper substrate by electroplating to form a tin or tin-lead alloy film coating. At present, impurities such as tin, tin-lead or tin-copper alloy and solder on the copper surface need to be removed after etching in the production of PCB negatives. The scavenger solutions commonly used in the industry in the past generally use two types of compositions. The most widely used in the past The composition used is based on an acidic solution containing fluorine peroxide and a fluoride. In recent years, the industry has cha...

AI Technical Summary

Problems solved by technology

[0005] The above-mentioned products have low tin, tin-lead and tin-copper dissolution amounts, and are easy to corrode the substrate and copper surface during use, oxidize the copper surface, reduce insulation resistance, and affect the quality of printed circuit boards. The speed of tin is slow, and the waste liquid generated is not easy to handle and has low recovery value, which is easy to cause environmental pollution