Speaker: Louis Rector, Ph.D.
Henkel Electronic Materials LLC, Irvine, CA
High power integrated circuit (IC) silicon die have traditionally been attached to the metal leadframe by either a highly silver-filled adhesive or a high lead content solder paste. The die attach material serves to position the die on the leadframe for subsequent wire bonding and encapsulation steps. The primary function of the conductive die attach material is to enhance the reliability of the electronic package and to control the die operating temperature by conducting heat out of the semiconductor package. IC chip transistor densities have been rapidly increasing in recent years which increases device thermal management issues. In addition pending international legislation restricts the use of hazardous substances and the known good thermal and reliability performance of high lead solder. Therefore, IC manufacturers are actively seeking alternative higher performance conductive die attach solutions.
This presentation will discuss two emerging materials technologies which are being developed to address the performance needs of the electronic marketplace. Low temperature (250°C) pressure-less silver sintering (SS) systems have been developed which demonstrate high levels of thermal conductivity and reliability performance. Transient liquid phase (TLP) sintering metal alloy systems represent a second avenue of conductive materials development. As the nomenclature implies a transient liquid phase is present in TLP sintering, which is consumed in the formation of subsequent intermetallics. Physical properties, morphologies and performance of representative SS and TLPS materials will be reviewed in this discussion.
Dr. Rector obtained a B.S. degree in Chemistry and in Chemical Engineering from the University of Illinois -Urbana-Champaign and a M.S. in Manufacturing Engineering and a Ph.D in Materials Science and Engineering, both from Northwestern University. His doctoral work at Northwestern involved the investigation of the charge transport mechanisms and morphology Kevlar®/Polypyrole electrically conductive fibers. He has 20 years of industrial experience and has been with Henkel Corporation for the past 13 years and has worked in a variety of materials development areas, including acrylate-based protective coatings, surge suppression composites for ESD protection, formulation and characterization of epoxy molding compounds for semiconductor packaging and the evaluation of new thermosetting resin chemistries for electronic packaging. Most recently his focus has been on the development of novel sintering metal compositions for electronic packaging applications.