Hot Dip Coatings vs. Electro-Tin Reflow
1. Thicker plating needed before reflow.
2. Smaller grain structure.
3. In most cases, and undercoat (nickel or copper) is used prior to Electro-Tinning; mainly for adhesion and whisker growth.
4. .00004" to .00008" per side
5. By reflowing, they are trying to establish larger grain structure and adhesion. This causes multiple processes.
1. Less Handling. One process used where Electro-Tin has to utilize many to establish what Hot-Dip already has. Ex: Good adhesion and large grain structure.
2. Large Grain Structure. This enhances the life of an ie: connector because of fewer pathways for base material diffusion to the surface. On the other hand, Electro-Tin has very small grains which means more paths and an increase in diffusion rate.
3. No additives to bath ensures best purity to tin bath.
4. Can also Tin at a thickness range of .00004" to .00008".