Experimental identification of warpage origination during the wafer level packaging process

Redistribution layer (RDL) composing of polyimide (PI) dielectric layer and electro-chemical deposited (ECD) Cu trace is a critical part for wafer level packaging (WLP). One concern of this multi-layered film structure is the wafer warpage induced during the process, which poses threats to automatic handling, 3-D integration and device reliability. In this… CONTINUE READING