Microwave integrated circuit process investigation. Work package 2: Hermetic sealing

Low temperature Microwave Integrated Circuit (MIC) hermetic sealing procedures were evaluated. Naked semiconductor chips mounted on MIC substrates are used in MIC technology if they are exposed to an inert atmosphere. This is accomplished using hermetic sealing, soldering or welding. From a reliability point of view the best solution would be to use low temperature sealing. From preliminary tests of six epoxies, Araldite AV/HV 100 and Epo-tek H 77 were selected. Environmental tests of MIC-boxes sealed in three different ways: using Araldite AV/HV 100, using Epo-tek H 77 or using indium as sealing material for the lid and Epo-tek H 77 as sealing material for the copper tubes, were made. It is shown that hermetic sealed MIC boxes can be obtained using indium as sealing material for the lid and either of the two epoxies for the copper tubes (for the helium refilling operation) and for the SMA connectors.