Chemical stannum-plating solution

Abstract

The invention provides an electroless tin plating solution, the components of which include stannous sulfate or stannous chloride, concentrated sulfuric acid, sodium hypophosphite, pyrithione hydrochloride, 4,4'-(2-pyridine methylene) di Phenol, Schiff base, polyethylene glycol 6000, amidinothiourea, etc. The tin plating solution is used to replace tin on the surface of steel, copper or copper alloy materials. The working temperature is 20-65°C, the plating time is 30-90 seconds, the thickness of the coating is 0.45-1.42μm, and the plating solution can be stored stably at room temperature. More than 90 days.

Description

Technical field

[0001] The invention relates to chemical plating on the surface of metal materials, in particular to a solution for chemical displacement tin plating on the surface of steel, copper or copper alloy substrates. Background technique

[0002] Tin plating is a coating with good solderability and certain corrosion resistance, which is widely used in the electronics industry. However, the coating obtained from the Sn electroplating solution is often accompanied by the precipitation of coarse particles and the growth of tin whiskers. This tin whisker is one of the main hazards that cause electrical short circuits. To avoid this situation, a coating thickness of 5 μm is necessary . Unlike electroless tin plating, there is no stress, the deposited particles are very small and dense, and there are no pinholes. The thickness of the coating layer of 0.45~1.2μm can meet the requirements of most users. Therefore, electroless tin plating is particularly suitable for the surface ...

Images