SOLDER JOINT STRUCTURE FOR BALL GRID ARRAY IN WAFER LEVEL PACKAGE

摘要

A semiconductor device package and a method for forming the package using an improved solder joint structure are disclosed. The package includes solder joints having a thinner bottom portion than a top portion. The bottom portion is surrounded by a molding compound and the top portion is not surrounded by the molding compound. The method includes depositing and forming a liquid molding compound around an intermediate solder joint using a release film, and then etching the molding compound to a reduced height. The resulting solder joint has no waist at the interface of the molding compound and the solder joint. The molding compound has a greater roughness after the etch, greater than about 3 microns, than the molding compound as formed.