Electroplated coatings of tin-lead alloys; Specification and test methods

2Scope / Description

This International Standard specifies requirements for elec-troplated coatings of tin-lead alloy containing between 50 % (m/m) and 70 % (m/m) of tin (see 10.3). It may be used for tin-lead alloys of other compositions but the properties of such coatings may be different from those of the alloy range quoted. A classification scheme is included by which the nature of the basis metal and the coating composition, within these limits, can be defined and which also contains provision for flow-melting and bright deposited coatings. The coatings are intended for use on fabricated metal articles and on printed circuit boards. It does not apply to a) threaded components; b) bearing overlays; c) coatings on sheet, strip or wire in unfabricated form, or of articles made from them; d) electroplating of steels with tensile strength greater than 1 000 MPa (or of corresponding hardness), because such steels are subject to hydrogen embrittlement (see 8.2). note: 1) 1 MPa = 1 N/mm