Ensuring Reliability: Measuring Pressure Distribution During Flip Chip and MEMS Sensor Encapsulation

摘要

This article investigates a new pressure measurement method usable during packaging of electronic systems. With pressure sensitive multilayers, it is possible to determine the pressure distribution on the surface of mold cavities and on various electronic substrates during packaging processes. The pressure sensitive multilayer is based on commercially available surface pressure indicating sensor films'", which change color directly proportional to the amount of pressure applied. Homogenous pressure distribution within the molding cavity is of particular importance for encapsulation of mechanically sensitive electronic components, e.g. MEMS sensors, bare dies, and flip chips. With the implementation of specially multilayered sensor films a fast estimation of the pressure distribution within the cavity, will be possible. We successfully used the new sensor concept to investigate industrial transfer molding processes with epoxy molding compounds (EMC). On distinct points of the mold cavity conventional piezo pressure sensors have been applied to get a time dependent pressure signal. $1Project Manager for Fraunhofer IZM - MMZ (Germany), one of the leading research institutions in the field of electronic packaging and system integration worldwide.$2President of Sensor Products Inc., headquartered in New Jersey (USA) and established in 1990, a world leader in the manufacture and distribution of tactile pressure sensing solutions.;