Existing alumina ceramic packages for high density multichip modules are no longer adequate in dissipating the heat that is generated by the increasing concentration of die per unit area (often exceeding 80% of the surface area), and in assuring signal pulse fidelity over a wide of the surface area), and in assuring signal pulse fidelity over a wide frequency range. Packages that combine these two demands (thermal and electrical) and are also hermetic do not exist; if they are not developed, the wider application of already available ASIC and memory devices will be impeded. The development of packages that combine high thermal conductivity with controlled impedance feed throughs will open up new opportunities for multichip module usage. The Phase I objective of this program is to select materials and develop processes for joining low-K LTCC ring formes to 2"x2" A1N package bases. This is the first step in the further development (Phase II) of a reliable, producible, and hermetically sealable package.
