Patent ID: 6844253

Claim:
A method of forming a solder ball contact, comprising: forming a metal contact pad on a substrate; forming an insulating layer on the metal contact pad; forming a patterned photoresist layer over the insulating layer; using the patterned photoresist layer as a mask to remove a portion of the insulating layer to expose a portion of the metal contact pad, thereby forming an exposed portion of the metal contact pad; depositing solder on the exposed portion of the metal contact pad after the mask is removed such that the depositing solder is performed with using the insulator as a mask, wherein depositing solder on the exposed portion of the metal contact pad uses a deposition process selected from a group consisting of selective chemical vapor deposition and selective electrolytic deposition, thereby forming a solder contact by selectively depositing solder and without removing a remaining portion of the insulating layer; and annealing the solder contact to form a solder ball contact having a diameter in a range of about 2.5 microns to no greater than 100 microns.