Larry Levy, Strategic Sales, FormFactor
Larry has been at FormFactor for over 20 years in a variety of roles, including product engineering, assembly and test, quality, applications and service, marketing and sales. Currently he specializes in parametric and photonics applications for probe cards. His areas of expertise include parametric, image sensors and LED testing, and he has presented a variety of papers at technical conferences such as International Test Conference (ITC), Semiconductor Wafer Test Workshop (SWTW) and COMPASS. He previously held positions as Sales and Regional Management for NTK Technical Ceramics in Texas and New Jersey.
Modeling and Minimizing Stray Capacitance for Parametric Probe Cards
The stray capacitance of probe cards is starting to impact certain parametric measurements. Prior to doing parametric test a procedure is usually performed to null out the capacitance produced by the tester and probe card. These days, with shrinking geometries and new test requirements, the capacitance induced by the card can become a large percent of the value we are trying to measure, thus introducing concern about the measurements accuracy. Stray capacitance in probe cards is usually measured in air. However, certain test structures in the wafer can also greatly contribute to the stray capacitance generated by the card. By localizing the values of stray capacitance produced by the main components of the probe card we were able to reengineer the card greatly reducing the stray capacitance while addressing the impact of potential structures in the wafer