RF MEMS Packaging for Space Applications

The Lockheed Martin/GE High Density Interconnect (HDI) packaging technology has been applied to packaging RF MEMS components for space applications. In previous work, HDI has been used to fabricate multi-chip modules (MCMs) for a wide range of applications from RF (70 MHz) to mm wave (94GHz) using GaAs MMICs and Si control circuits by embedding the active components in a polymeric structure. This packaging technology is an alternative to the use of LTCC and HTCC ceramic based MCMs. The GaAs MMICs used in these modules are fabricated with fragile air-bridges that require protection from physical damage and intrusion of dielectric materials. For this reason, an air-capping process has been developed that places an air pocket over the critical elements of each MMIC within the HDI MCM thereby protecting the fragile airbridge structures from physical damage. This same technique has now been used to provide an air pocket over the critical moving elements of RF MEMS devices. This packaging technology can be used to produce MCMs that contain MEMS and MMIC devices as well as Si control ICs.