Prevention of Tin Whisker Growing
Tin whisker growing is a phenomenon related mainly to pure bright tin (Sn) terminal finishes. The whiskers may cause shorts between electrical terminals, therefore actions to prevent whisker growing have to be undertaken.
Usage of hot dipped SnAgCu alloys
Most Diotec parts are using SnAgCu alloy for terminal finish, which is applied in a hot dip tinning process. After plating, there is an annealing at 150°C for at least 1h. A nickel (Ni) underplating provides additional protection against tin whisker growing. For this reason, SnAgCu alloys with above treatment are preferred terminal finishes for prevention of tin whisker growing at Diotec.
Matte Sn plating with annealing
At this process, matte Sn is applied, without usage of a brightener. After plating, there is an annealing at 150°C for at least 1h. This measures prevent tin whisker growing even at a pure Sn plating. Therefore it is an accepted method for tin whisker prevention.