A matched expansion MEMS probe card with low CTE LTCC substrate

This paper describes the fabrication technology of a new MEMS-based probe card. The probe card is designed to satisfy requirements from advanced wafer-level burn-in LSI tests. The problem of thermal expansion mismatch between the probe card and LSI wafers is solved by using a LTCC (low temperature cofired ceramics) substrate with a coefficient of thermal expansion of 3.4 ppm/°. The probes are first formed on a silicon wafer, and then transferred to the LTCC substrate using Au/Sn solder bumps. The prototyped probe card was preliminarily evaluated in contact resistance. The measured contact resistance was 0.14 Ή during 2500 touchdowns.