Silicon Die Bonding using a Photostructurable Adhesive Material

Abstract

For a novel packaging application, a method is needed to bond silicon chips on a wafer surface. One of the main requirements is a comparably thin and structurable adhesive layer. The adhesive layer has to have a thickness of approximately 10 to 20 μm and is required to cover the edges of the silicon die. As this application is quite unique, thorough research has been done to identify applicable materials and processes. Common technologies like die bonding, pin transfer, jetting etc. cannot be used as the adhesive volume has to be controlled very precise and the dimensions of the adhesive bond are too coarse for the application. The desired thickness of the adhesion layer can only be achieved using photostructurable materials. A parameter analysis has been done in order to determine applicability of the photostructurable material as an adhesive layer. Therefore, die bonding temperature and bonding pressure have been varied. The influence of the parameter variation has been demonstrated using die shear testing and cross sectional imaging. Two geometrical variations of the adhesive layer are compared. A sufficient parameter set could be identified using this approach.