The alloy layer of tinplate is an intermetallic compound formed between base plate and tin coating through thermodiffusion during the treatment of heating and fusing after electrotinning.

镀锡合金层是镀锡后在加热熔程中通热扩散在锡层之间生成的一种金属间化合物,因此,合金层的生成原和镀层都有很大关系。