| abstract |
An improved structure of a ball-grid array (BGA) package substrate and processes for producing thereof are disclosed, wherein one side of the BGA substrate has a single pattern layer for connecting with solder balls and a heat sink layer is bonded to the other side of the substrate. The heat sink layer provides not only heat dissipation for the substrate, but also patterns for power and/or for ground, so as to diminish the dimension required for the patterns for power and/or for ground on the pattern layer of the substrate. The solder balls for power and/or for ground of the substrate are connected with the heat sink layer through electrically and thermally conductive via holes plugged with conductive paste. |