Integrated Functional Materials for System-in-Package Applications

Integrated electronics technology continues to advance across an ever wider range of frequencies, at ever greater circuit densities. Increasingly research and development is being directed at supplementing the capabilities of monolithic silicon circuits with additional functional and structural materials, closely integrated using system-in-package (SiP) technology. This approach plays well to UK strengths, where the capability in advanced materials such as technical ceramics and polymers, and in alternative micro-structures such as MEMS devices, is very strong. This proposal brings together three leading groups in the areas of microfabrication and MEMS (Imperial), advanced thin film materials (Cranfield and Leeds), and radio frequency applications (Leeds), creating a consortium ideally placed to advance the SiP field. The project will develop enabling technologies for this industry trend through work on three themes:i. integration of functional ceramic films into electrical and RF components, for enhanced performance or new functionality;ii. development of novel functional ceramic films, including lead-free electro-ceramics for reduced environmental impact;iii. integration of material combinations traditionally seen as incompatible because of material mis-match or processing incompatibility, and technologies for building circuits on new low-cost substrates. For each theme, the work will be organised within a separate workpackage. Components which will be developed include variable capacitors, transmission lines and filters; and sensors based on thin-film bulk acoustic resonators. Research on materials will focus on microwave dielectrics and ferrites. The integration work will include several methods for the transfer of ceramic films from high temperature- to polymeric- substrates, and bonding techniques for such substrates. A fourth workpackage will target an overall systems demonstrator to integrate the results of the separate themes.The project will build on developments in the two Exploratory projects currently being undertaken by the proposers: on processes for Laser-Lift-Off and bonding (Leeds), and on integration of advanced ceramic films in MEMS 3D structures and devices (Cranfield and Imperial).