Abstract: A structure and method (1000) of forming an interface for a ball grid array includes forming pad (204), (1002) on a substrate (202) and creating a positive feature (206) on the pad (1004). The positive feature (206) provides an interface for a solder ball (208). The improved pad can be incorporated as part of BGA substrate or as part of a printed circuit board substrate. The positive feature (206) provides a contoured or uneven profile having vertical surfaces that increase the pad's surface area without taking up additional substrate space. The vertical surface area interrupts propagation of any fracture incurred during drop and vibration.

Abstract: An improved method of applying a particulate material to a substrate, includes the steps of: removing impurities from a surface of the substrate; forming a coating composition having a bonding material and at least one particulate material; applying the coating composition to the substrate surface; and creating a diffusion bond between the substrate, bonding material and particulate material for generating a continuous interface between the substrate surface and particulate material such that the change in mechanical properties between the substrate and particulate material occurs in a direction normal to the plane of the substrate surface, thereby minimizing residual strain and coefficient of thermal expansion mismatch between the substrate and particulate material, the surfaces of individual particles of said particulate material being chemically wetted by the bonding material. The particulate material and the bonding material comprise a layer on the substrate surface.