Six-gigahertz equivalent circuit model of an RF membrane probe card

Installed on manufacturing probe stations, the membrane probe card is a production test board for high-volume radio frequency (RF) wafer testing. Replacing dc needle probes with an RF membrane probe permits RF measurements at the die level. Both physically and electrically, the membrane probe resembles the components and packaging of the final product. Die tested using a properly designed membrane probe card should exhibit RF performance comparable to an assembled component. To guide an effective membrane probe-card design, it helps to have a well-characterized example. This paper details a lumped-element equivalent-circuit model of an RF membrane probe card, suitable for reference in designing general-purpose RF membrane probe cards. Along with the equivalent-circuit model, the characterization methodology is discussed