FLIP CHIP ALIGNMENT MARK EXPOSING METHOD ENABLING WAFER LEVEL UNDERFILL

摘要

Alignment marks on a semiconductor device surface are exposed and exposed surfaces cleaned after an obscuring coating is applied over the surface and marks. The surface can be an attachment surface of the device and can include C4 solder bumps of a flip-chip type device and the coating can include a wafer level underfill coating that is substantially optically opaque. Laser ablation, such as with a UV laser, can remove the coating while minimizing heat transfer to the device.