Flip Chip on Flex circuitry is evolving technology in Electronic Packaging. The Silicon chip (IC Chip) is directly attached to the flex substrate. The electrical interconnections are provided by the solder balls. The underfill material fills the gap between the Chip and the Flex, also it encapsulate the solder ball interconnects. Use of Flex circuitry has tremendous advantages over the conventional rigid substrates. The Flex substrates provide highly dense wiring network which makes the package smaller in size and allows the utilization of larger Chip size. This miniature packages will make the electronic appliances such as Hand Phones and Palm tops even smaller than the present ones.

Polyimide (PI) films are in extensive use in the Flex industry. The chemical structure of PI imparts excellent electrical and thermal properties, however it exhibits poor adhesion at the interface with the rest of the package components.

My research in IMRE deals with improving the adhesion of Polyimide interface for high density Flex circuits. My focus will be the adhesion at Polyimide-adhesive (or underfill) interface and Polyimide-metal interface. Chemical modifications of Polyimide surface, keeping its bulk properties intact will be explored during this project.