MASKLESS PROCESS FOR SOLDER BUMPS PRODUCTION

摘要

Methods of producing a solder bump are presented. Preferred methods lack a requirement for photoresist processing or masking a target substrate. Contemplated methods include forming a well around one or more bond pads on a wafer where the walls of the well are formed by a passivation layer material. Contact material can comprise a solder paste or an under bump metallization layer, which can be placed within the wells as a contact bed for solder balls. A priori prepared solder balls, in solid form or in molten form, can deposited on the contact material to produce the solder bump.