Two-metal layer ball grid array and chip scale package having local interconnects used in wire-bonded and flip-chip semiconductor assembly

摘要

The present invention comprises a low cost device (10, 20) and a method (30) of forming an electrical interconnect between two metal substrate layers configured in a flip-chip format or a wire bonded format. The invention includes a first metal substrate layer (12), a second metal substrate layer (14), and an organic tape layer (16) attached therebetween as a dielectric. The organic tape layer (16) includes a series of spaced apart vias (15) adapted to receive solder paste (13). The second metal layer (14) includes a plurality of openings (40,42,44) spaced along the surface thereof and coaxially aligned with the spaced vias (15). Further, the invention includes a plurality of solder balls (17, 18, 19) placed across the respective openings (40,42,44) of the second metal layer (14) such that each solder ball (17-19) attaches to the solder paste (13) forming an electrical interconnect running substantially in parallel between the metal layers (12, 14). The solder balls are adapted to communicate I/O signals or power to/from an IC supported on the first layer.