BS 1872:1984

Appearance, heat treatment, sampling and undercoats of tin coatings on fabricated articles of metal and on printed circuit boards. Classification. Requirements and test methods for thickness, adhesion, porosity and solderability. Lists information to be supplied by the purchaser to the electroplater.

This British Standard specifies requirements for electroplated coatings of tin. The coatings may be dull or bright as electroplated, or may be flow-melted by fusion after electroplating. These coatings are intended for use on ferrous and non-ferrous basis metals and also on printed wiring boards. A classification scheme is included by which the nature of the basis metal and undercoat, if any, and the tin coating thickness can be defined. This standard does not specify any requirements for the condition, finish or surface roughness of the basis material before electroplating (see A.3). NOTE 1 Attention is drawn to BS 9760, which specifies capability approval procedure and rules for printed circuits of assessed quality. The standard is not applicable to electroplating of: threaded components (see BS 3382-5); tin coated copper wire (see BS 4393); sheet, strip (see BS 2920) or wire in the unfabricated form, or of coil springs; steels with tensile strengths greater than 1 000 MPa because such steels require hydrogen embrittlement relief after plating (see clause 6). This standard does not apply to coatings applied by other processes, e.g. autocatalytic, immersion or “electroless” processes. NOTE 2 The titles of the publications referred to in this standard are listed on the inside back cover.