Stud bump structure for semiconductor package assemblies

A method of forming a stud bump structure in a package structure, comprising:

• providing a conductive wire;
• pressing one end of the conductive wire to a bond pad and melting the conductive wire end to form a stud bump on the bond pad;
• severing the other end of the conductive wire close above the stud bump;
• and
• soldering a solder ball to a top surface of the stud bump, the solder ball encapsulating the stud bump.

A method for forming a package structure, the method comprising:

• providing a die wherein the die has a first periphery region adjacent a first edge of the die and a second periphery region adjacent a second edge of the die opposing the first edge of the die, and a center region interposing the first and second periphery regions;
• providing a substrate;
• bonding the substrate and the die, wherein the bonding includes:
• determining a bonding design pattern based on a stress of the bonded substrate and die, wherein the bonding design pattern provides a plurality of stud bump structures disposed within the first periphery region and the second periphery region of the die and a plurality of conductive structures disposed in the center region of the die;
• according to the bonding design pattern, forming the plurality of stud bump structures connecting the die to the substrate, wherein each stud bump structure of the plurality of stud bump structures comprises a stud bump and a solder ball encapsulating the stud bump;
• and
• forming the plurality of conductive structures connecting the die to the substrate, wherein each of the conductive structures is free of an encapsulating configuration.

A method, comprising:

• providing a surface of one of a die or a substrate, wherein the surface includes a plurality of bond pads;
• pressing a conductive wire onto a first bond pad of the plurality of bond pads, wherein the pressing includes melting an end of the conductive wire to form a stud bump;
• severing the conductive wire forming a tail on the stud bump;
• soldering a first solder ball onto the stud bump, the solder ball encapsulating the stud bump including the tail, wherein the first solder ball has an exposed curvilinear surface over the tail of the stud bump;
• and
• soldering a second solder bump onto a second bond pad of the plurality of bond pads wherein the second solder bump is free of an encapsulating configuration.