Optical packaging differs from traditional packaging in several ways, and many of these differences emerge from the need to protect the electrical, mechanical, and optical components of a system while preserving its exposure to the environment. Thus, the materials and packaging processes involved in such a system must be chosen with these goals in mind. This research project seeks to ascertain reliable and feasible hermetic packaging methods to ensure mechanical durability as well as insulation from electrical leakage for an optical feed-through operating in highly variable temperature environments. Several sealant materials and bonding processes appropriate for hermetic sealing are discussed in terms of induced stress, hermetic lifetime, and electrical characteristics. From this preliminary evaluation, hermetic bonding experiments and reliability tests are conducted. Some of the candidates show satisfactory performance, while others partially satisfy the requirements of this project. Advanced bonding techniques and feed-through design improvements have been introduced to secure highly promising sealing performance and to prevent some potential problems. This includes the multi-material composite bonding with advantageous feed-through re-formation and bonding alignment using light diffraction. Finally, this study offers basic guidelines for the materials and processing techniques needed for this system with several design variations considered.
Project end date: 01/26/11