Method of controlling solder ball size of BGA IC components

Abstract

A ball grid array (BGA) package which has a plurality of solder balls attached to solder landings that each have a number of tabs which extend from a center area of the landing. The tabs assist in a symmetric formation of solder balls that are formed on the landings. When constructing the package, a solder mask is applied to a bottom package surface before the application of the solder balls. The solder mask has a plurality of openings which expose the solder landings and are larger than the center area of the landings. Solder balls are then placed onto the solder landings and reflowed so that the balls become attached to the landings. The fully exposed center areas of the solder landings allow the solder to flow vertically along the outer walls of the landings, thereby providing a more robust solder joint. The exposed solder landings also allow a solder flux to be thoroughly cleaned after the solder balls are attached to the landings. Additionally, the land tabs insure an even solder flow about the solder landings to produce a symmetric uniform solder balls.

Dependencies are inferred from the claim text.