Inclination determining method for formation of whiskers in pure tin layer of electronic component, involves determining surface occupation by connections, and judging inclination for formation of whiskers from surface occupation

摘要

The method involves chemically removing a pure tin layer (7) from a cupriferous base layer (5) by using acid, which is selected from one of hydrochloric acid, nitric acid and sulfuric acid. The base layer is rinsed and dried after the removal of the tin layer. An evaluation unit (41) i.e. computer with image processing software, is used to determine surface occupation by intermetallic connections at a surface of the base layer. Inclination is judged for formation of whiskers from the surface occupation. An enlarged image of the base layer is picked up with a scanning electron microscope. An independent claim is also included for a device for determining inclination for formation of whiskers in a pure tin layer applied on a cupriferous base layer, comprising a reaction chamber.