Universal solder for optical and MEMS packaging


Sungho Jin

University of  California, San Diego, La Jolla, CA 92130-0411.






There is a need to directly bond a wide variety of inorganic materials such as oxides, nitrides, carbides, fluorides, diamond, and semiconductors in the packaging of optical, MEMS, and electronic devices,. Such applications involve hermetic sealing components, three-dimensional MEMS assembly components as well as active semiconductor or optical  components, dielectric layers, diffusion barriers, wave guides, and heat sinks.  These materials are known to be very difficult to wet and bond with low melting point solders.   In this presentation, new Sn-Ag or Au-Sn based universal solders doped with a small amount of rare-earth  elements which now allow direct and powerful bonding onto the surfaces of various MEMS, optical or electronic device materials.  The microstructure, interface properties, and mechanical behavior of the bonds will be described, and the areas for further improvement will be discussed.  Potential packaging applications of these new solder materials for  devices  including MEMS and  optical fiber devices  will also be discussed.