Design and Processing Considerations for the Use of a Crystallising Low Temperature Cofiring Ceramic Tape System with Integratable Passive Components

Low temperature cofiring ceramic tape (LTCC) is increasingly used for the production of complex three‐dimensional multilayer interconnect structures in microelectronics packaging. LTCC technology offers many attractive features including mechanical strength, high temperature performance, hermeticity and, with advanced crystallisable ceramic compositions, such as the Ferro A6 tape, outstanding microwave performance. Key among properties that discriminate LTCC technology from competing packaging approaches are two features that allow both design flexibility and maximum integratability: the ability to integrate the full range of passive components — resistors, capacitors and inductors — within the monolithic LTCC structure: and the fact that the LTCC interconnect system provides not only the interchip connection but also the package itself for the components, that is, the LTCC does not have to be placed in a further level of packaging before use. In this paper, the flexibility of design achievable with this company's A6 tape system including integratable passive components is discussed. Design rules that should be observed with the system to ensure that maximum benefit can be obtained from the key performance characteristics of the LTCC materials are addressed. Data supporting these design considerations are presented, as is a review of production processing parameters and their effect on yield, performance and cost of modules produced using the system. Specific project examples are reviewed to demonstrate the applications of this technology in advanced packaging design.