Novel Ceramic Packages and Architectures For MST Applications Made Possible With Photoimageable LTCC

摘要

Ceramic packages offer many advantages over plastic, such as hermetic capability, ability to operate over wide temperature ranges and in harsh environments, and are often chosen when the highest possible robustness and reliability are required. However, ceramic packages can require more costly, capital intensive processing (e.g., screen printing, punching, laser ablation) to form the ceramic structures. In contrast, plastic packages, often made by low cost, high volume manufacturing techniques, e.g., molding and extrusion, are chosen where the robustness and hermetic capabilities of ceramic are not important. The development of new Photoimageable Low Temperature Cofired Ceramic (PI-LTCC) is expected to tilt the balance in favor of ceramic packages, especially for future MST, MEMS, and MOEMS devices (e.g., microfluidic, fiber optic and custom RF packages). These newer applications will invoke more complex structures and architectures that are difficult or too costly to accomplish in conventional ceramic. Photo processing offered by PI-LTCC is also ideally suited for these emerging applications, where fast prototyping, mass production capability and low manufacturing cost are valued. The principal advantage PI-LTCC offers over conventional ceramic and standard LTCC lies in the ease with which features and architectures can be designed and fabricated, potentially with virtually continuous processing. Features in standard LTCC are formed by "green" punching, stamping or laser ablation, methods requiring significant investment in tooling and equipment. These mechanical processes do not lend themselves readily to rapid design changes, and have limitations for complex or non-standard architectures. Furthermore, highly automated and continuous (e.g., "reel-to-reel") processing is difficult or unfeasible. This paper will discuss design capabilities and limitations for the new PI-LTCC technology, highlighting some specific architectures that have been demonstrated, and will discuss potential markets where the materials have value and will find applications in the future.