A method of forming micro solder balls for use in a C4 process is described. The solder balls are formed by laying down a peel-away photoresist layer, forming holes in the photoresist layer to expose electrical contacts, depositing a solder layer over the photoresist, forming solder areas in the holes...http://www.google.es/patents/US6998711?utm_source=gb-gplus-sharePatente US6998711 - Method of forming a micro solder ball for use in C4 bonding process
Method of forming a micro solder ball for use in C4 bonding process
