TOK's Semiconductor Packaging Field
We are focused on developing photoresists for plating to address redistribution layers (RDLs) aimed at ultra-small targets and continuous electrolytic plating. We are also focused on developing photoresists for plating that target the formation of μ-bumps, tall copper pillars, and stud gold bumps.
The advantages of positive photoresists include not only their proven track record by customers and their resolution and rectangularity, but also their detachability and resistance to electrolytic plating solution processes (flexibility and resistance to plating chemicals), compared with dry film photoresists and negative photoresists.
Going forward, TOK will continue devoting efforts to helping improve the yields of our customers.