Here is the abstract you requested from the nano_2012 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.
|Use of Parylene as a 3D TSV Strain Relief Jacket|
|Keywords: TCE Mismatch, TSV extrusion failure, Parylene Stress Relief Jacket|
|Cu TSV's in 3D integration are well established. However, a known problem is the extrusion of the Cu out the ends of the TSV tunnel when exposed to elevated temperatures such as used for soldering. This is due to the dissimilar CTE's for Cu and Si, and the mechanical hardness of the Silicon relative to Cu. This can disrupt solder bumps or other interconnection structures at the ends of the TSV as the Cu extrudes. In this paper we explore the use of various Vapor Deposited Polymers (VDP) in the Parylene family as a conformal coater of the TSV tunnel to provide a stress relief layer. The relative softness of this polymer jacket can deform and expand reversibly. In particular a new Parylene derivative, Parylene-X, is explored as it provides two levels of cross linking for its ability to withstand solder temperatures. Various adhesion promotor strategies are discussed. In addition the low dielectric constant can help reduce electrical cross coupling between adjacent TSV's. The polymer jacket is, however, a thermal insulator and so the implications of this are explored. COMSOL is used to perform thermal, mechanical and electrical modeling.|
|John F. McDonald, Full Professor