TINNING COAT, TINNING LIQUID FOR FORMING TINNING COAT, METHOD FOR FORMING TINNING COAT AND CHIP TYPE ELECTRONIC PARTS FORMED OF ELECTRODE WITH TINNING COAT

摘要

PROBLEM TO BE SOLVED: To provide a technique capable of forming a tinning coat which generates no whisker under severe thermal shock test conditions and is not affected by substrate metal.;SOLUTION: The tinning coat provided by electrolyzing a tinning liquid includes a compression stress and has such an anti-whisker characteristic that the compression stress measured by the spiral method is at least 1 MPa. Further upon the formation of the tinning coat, tin methanesulfonate is used as a supply source and the tinning liquid or the like which contains sodium sulfate as a conductive salt and an amphoteric surface active agent is used.;COPYRIGHT: (C)2007,JPO&INPIT