Abstract: The invention consists of a wafer-level expansion-matched design which forces a substrate to expand and contract at the same rate as a surface-mounted component, which reduces mechanical stress on the component. An embodiment of an expansion-matched MUX design consists of two pieces of silicon sandwiching a shim, which has a higher CTE than the silicon. By modifying the silicon thickness, shim thickness, and shim material, the CTE of the composite structure may be tailored. The composite structure is produced by a wafer level bonding approach to the balanced stack. Performing the bonding at the wafer level reduces die level touch time and improves planarity. Furthermore, a wafer level solution facilitates fabrication processes at elevated temperatures as the match occurs for both heating and cooling.