Near-Hermetic High Power Package using Liquid Crystal Polymer for 4-Watt Ka-Band Amplifier with Sparse Thermal Vias for Cost Reduction

摘要

This paper presents the design and development of a 10W power package at Ka-band with near a hermetic sealingrncavity. The package has a 12x12x0.5 mm copper heat spreader on which Liquid Crystal Polymer films arernlaminated to form 50Ω feed-thru transition to a mother board. The experiment results demonstrate that a packagedrnGaAs power amplifier dissipating 10W DC power has the maximum channel temperature of 143.9℃. The Tchrntemperature is obtained using infrared thermal mapping technique with baseplate temperature at 80℃. Also therneffect of using sparse corner vias at the PCB level will be presented as well. By reducing the number of vias at therncorners from 196 to 148, a 24.4% reduction, the channel temperature of the packaged amplifier maintainsrnapproximately the same temperature. This LCP package will be near-hermetic without extra adhesive and willrnprovide enough power dissipation up to 10W to maintain GaAs device lifetime at Ka-band.