BS EN 60512-16-21:2012

1 Scope and object
2 Normative references
3 Terms and definitions
4 Test equipment
5 Preparation of the specimens
6 Measurement of whisker length
7 Test method
8 Requirements
9 Information to be recorded
10 Details to be specified
Annex A (informative) - Whisker growth due to mechanical
        stresses induced by assembly processes and
        intended usage
Annex ZA (normative) - Normative references to international
         publications with their corresponding European
         publications

Specifies a standard test method to assess the possibility of whisker growth by external mechanical stress on the tin and tin-alloy plated parts of a connector in its application (after wire termination, after soldering, after mounting, mated with counterpart).

This part of IEC 60512, when required by the detail specification, is used for testing connectors within the scope of IEC technical committee 48. It may also be used for similar devices when specified in a detail specification.

The object of this standard is to define a standard test method to assess the possibility of whisker growth by external mechanical stress on the tin and tin-alloy plated parts of a connector in its application (after wire termination, after soldering, after mounting, mated with counterpart).

This standard does not cover internal stress type whisker.

NOTE 1 The test method dealing with internal stress type whisker, which is caused by the formation of intermetallic compound by diffusion, or by the formation of oxide film of the plating surface, or by the difference between coefficients of thermal expansion, is specified in IEC 60068-2-82.

While for internal stress type whisker, it is possible to apply accelerated test conditions, e.g.: by damp heat or temperature cycling, for the external mechanical stress type whisker covered by this standard, due to the different whisker generation mechanism, there are no accelerated conditions. The test detailed in this standard shall then be conducted under normal ambient conditions.

NOTE 2 Physical changes during the application process may cause changes of the material qualities, so that this test cannot be used as a qualification test of a connector in ‘as produced’ condition.

NOTE 3 The conditions specified in this test may accelerate the growth of tin whiskers in a test specimen, but no correlation has been demonstrated between the extent of whisker growth, which may occur in this test, and the extent of whisker growth which may be expected in actual use. Whisker growth in actual use may therefore be less than or greater than the extent of whisker growth found when using this test.