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BGA solder joint

IP.com Disclosure Number: IPCOM000013872D
Original Publication Date: 2001-Mar-01
Included in the Prior Art Database: 2003-Jun-18

Publishing Venue



Disclosed is BGA Ball Grid Array solder ball joint consisting of a BGA solder ball and a pad with projections. Higher accuracy of a solder ball against a pad can be easily secured with this solder joint structure. Figure 1 shows a fundamental structure of the BGA solder ball joint on the pad which has projections, whose number is more than three. The projections are formed with electroplating or electroless plating and are placed on a concentric circle. This solder ball joint has excellent accuracy of solder ball against pad superior to the conventional solder ball joint which consists of a BGA solder ball and a flat pad. With a flat pad, the solder ball are easily displaced during soldering process under the influences of flux and/or solder, which results in soldering defects or low joint strength. Projections on a pad are effective in preventing the displacement of thesolder ball. The observation of the visual inspection of the BGA solder ball joint has shown that there were no substantial defects, such as bridges and misalignments. 1