Advanced packaging and low cost manufacturing techniques for GaAs microwave modules

Summary form only given. A new innovative package design using a common RF, DC, and logic carrier with a formed lid structure has been developed for batch processing. Aluminum-silicon composite housings under development offer improved thermal conductivity, lighter weight, lower cost, and the potential of direct attachment of GaAs chips to the housing. Substrate technologies include glass-on-silicon RF substrates which significantly reduce the module part count. A four-to-one reduction in part count and cost was achieved in an RF receiver subassembly using a single substrate and thin-film passive element deposition with this technology. Cofired multilayer ceramic substrates were developed to incorporate logic, power conditions, and RF circuitry. Technologies developed for assemblies include high-precision chip component pick-and-place, automated epoxy chip attachment techniques, and void-free solder attachment using a vacuum system. Vacuum pick-up techniques were developed for the pick-and-place assembly of GaAs MMIC chips to eliminate negative yield factors. Power MMIC chips were effectively soldered with the void-free solder attachment. Highly automated testing techniques have been developed for rapid measurement of pulsed large- and small-signal S-parameters, high dynamic range automated spurious checks, and full S-parameter characterization for all amplitude and phase module settings.<
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