3D chip integration processes use thinned silicon wafers in conjunction with through silicon vias. Polyimide adhesives are evaluated for use as temporary and permanent adhesives to enahle handling of thinned wafers and subsequent bonding into 3D stacks. These adhesives are found to have a combination of thermal and mechanical properties and processing capabilities required for 3D chip integration applications.

This paper will examine the combined use of both permanent and temporary high-temperature polyimide adhesives used to avoid thin wafer handling. While 3D-TSV technology can improve functionality and performance, adoption of this technology has been delayed by cracking as well as unwanted wafer bowing. This presentation shows means by which a photo-lithographic polyimide adhesive is used in a temporary bonding scheme to eliminate intermediate-stage thinned wafer handling.