Patent ID: 6884717

Claim:
The method of fabricating a backside surface of a wafer of microwave radio frequency circuit die, said method comprising the steps of: forming an array of via holes of selected location and depth dimension in said wafer of circuit die; said via holes being located in response to selected microwave radio frequency electrical component locations over said front side surface of said wafer circuit die; said step of forming an array of via holes being performed during a front side accessing of said wafer of circuit die; disposing a grid pattern mask on said backside surface of said wafer of microwave radio frequency circuit die; said grid pattern mask including a backside periphery outline masking for each circuit die of said wafer; removing a layer of selected thickness from said wafer backside surface, said removing being from exposed backside surface areas intermediate elements of said grid pattern mask; said removing step leaving recessed valley portions of selected thickness disposed intermediate individual circuit die-strengthening upstanding surrounding bluff masked semiconductor regions in said wafer backside surface and exposing backside portions of said formed front side via holes; and interconnecting front side and back side ground plane microwave radio frequency energy conveying metal conductors of said wafer circuit die by way of metallic conductors traversing said via holes.