Electrochems

→ Process	Sputtering	Lithography	Bump plating	Stripping/Etching
→ Material	Ti/Cu	Dry Film/Liquid Film	Cu/Ni/SnAg/Au	Ti/Cu etching solution
→ Characteristic	Good continuity	Photoresist thickness 5 ~ 200 um Aspect ratio 1:3	Aspect ratio 1:3 Uniformity < 10%	High metal selection ratio, no damage to Oxide and metal bumps Undercut < 1um

Compared with solder paste printing, tin quantity control is precise and it has excellent electroplating alignment accuracy.
Compatible with Fine Pitch products.
Compared with gold-tin, it has the advantages of low cost, lower reflow temperature can be used, and the substrate flatness tolerance is large.
Thermal Resistance.
Thick nickel barrier (3 um) resists tin drilling.