An interconnection technology may use molded solder to define solder balls. A mask layer may be patterned to form cavities and solder paste deposited in the cavities. Upon heating, solder balls are formed. The cavity is defined by spaced walls to keep the solder ball from bridging during a bonding process. In some embodiments, the solder bumps connected to the solder balls may have facing surfaces which are larger than the facing surfaces of the solder ball.