Thin film silicon substrates for lead frame packages

Silicon based thin-film substrates provides a technology to meet the increasing demands on the packages as the dimensions of the semiconductors gets smaller and the pad density increases. The substrates are excellent for applications in thin packages, either in stacked or side-by-side applications, since the substrate can be back-grinded and handled as any other piece of silicon in the assembly process. The substrate is used both for rerouting of the signals interconnecting the dies in the package and acts as a bond support to shorten the bond wires and thereby increasing the assembly yields. Since the substrate is made of the same material as the other components in the package, the thermal stresses in the stack will be minimal. The use of thin-film silicon substrates can lower the total cost of a package at the same time as it is increasing the functionality and the yields of the packaged products.