A novel thick film on ceramic MCM technology offering MCM-D performance

The majority of MCM circuits fall into one of three main categories: MCM-D offering high performance at high cost; MCM-C offering restricted performance at lower cost; MCM-L offering restricted performance at lowest cost. Thick film technology has been used relatively little due to its performance limitations with regard to geometrical constraints and poor material performance for high speed applications. This paper describes and discusses the performance of MCM structures fabricated using an advanced thick film conductor and dielectric technology on standard ceramic substrates. The resulting MCMs offer performance similar to MCM-D, with significant cost benefits. Line widths better than 25 microns and via geometries better than 50 microns resulting from a combination of novel materials and processing, give excellent geometrical properties. The novel dielectric material provides a dielectric constant of less than 4, with a loss factor better than 1×10^-4. The paper concentrates on the performance of the technology, but also discusses the technology and its processing. In particular, the ability of the technology to generate MCM structures operating at microwave frequencies is illustrated