Here is the abstract you requested from the IMAPS_2007 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|A Novel Three-Dimensional Packaging Method for Al-metallized SiC Power Devices|
|Keywords: 3D packaging, SiC power device, Au stud bump|
|Abstract-A novel three-dimensional packaging method for Al-metallized SiC power devices has been developed. This method includes is a combination of Au stud bumping on an Al-metallized electrode of a power device chip and a subsequent vacuum reflow soldering with Au-20Sn solder paste. The die shear strength of a SiC power device bonded on a AlN/Cu/Ni(Au) substrate with Au stud bumps and Au-20Sn solder increased with the number of Au stud bumps. The die shear strength of the SiC chip with the number of Au stud bumps of 36 and 289 reached up to 37.6MPa and 78.7MPa, respectively, which was much higher than the shear strength of the widely used die bond material Pb-10Pb (13MPa) and sintered Ag paste (5MPa). This indicates that an Al-metallized electrode of a power chip can be solidly assembled to a AlN/Cu/Ni(Au) substrate by this novel method. The bonded SiC-SBD chips were stored at 250 ¡æ in a vacuum oven and their morphology, shear strength and electrical properties at 25, 100, 150 and 200¡æwere investigated after a certain aging time. After 300 hrs, the resistance of the bonded SiC-SBD chips only increased 0.4%, and the die shear strength only decreased 7%. No morphological change in the interface was observed by a micro focus X-ray TV system after long term storage at 250¡æ. Very little diffusion between the Au bumps and Au-20Sn solder was observed in the cross-section of the sample by scanning electron microscope (SEM) equipped with an energy dispersed X-ray analyzer (EDX). This chip joint method presents a novel approach for 3-D packaging SiC power devices with Al electrodes and can be applied to various electrode size and shape.|
National Institute of Advanced Industrial Science and Technology (AIST)
Tsukuba, Ibaraki 305-8568,