2,808
edits
Changes
→7.1.2.4 Electroless Deposition of Nickel/Gold
(DODUBOND process). This Pd layer acts as a diffusion barrier and allows the usage of this surface combination also for gold wire bonding.
As an alternative, for gold wire bonding applications a thicker gold layer of 0.2 – 0.5 μm can be applied using an electroless process. Typical electrolytes work at a temperature of approx. 80°C with deposition rates of 0.3 – 0.4 μm per 30 minutes. There are however limitations with these electroless electrolytes concerning their stability and the robustness of the process compared to other electroplating processes which reduces their wider usage <xr id="tabfig:Coating composition of a printed circuit board"/> (Fig. 7.3).
====7.1.2.5 Immersion Deposition of Tin====