This　work　optimizes　the　liquid-cooled　microchannels　on　the　cold　plate　using　a　variable-density　topology　optimization　[1]　approach　to　increase　the　heat　dissipation　of　transmit-receive　modules　within　active　phased　array　antennas　and　their　dependability.　Proposing　a　system-level　channel　heat　dissipation,board-level　and　component-level　sets　make　up　the　structure　of　the　system-level　channel　cooling,　with　channel　branches　distributing　flow　from　the　board-level　channels　to　the　component-level　microchannels.　With　fluid　energy　dissipation　[2]　and　average　temperature　as　goals,　a　two-dimensional　variable-density　topology　optimization　approach　was　used　to　optimize　the　microchannel　architectures　in　COMSOL　Multiphysics　software.　Thermal-fluid　coupling　simulations　were　performed　using　ICEPAK　finite　element　software　to　compare　the　heat　dissipation　performance　between　system-level　channel　cooling　and　cold　plate　cooling,　as　well　as　the　heat　transfer　efficiency　between　the　optimized　topology　channels　and　conventional　parallel　cold　plates.　The　finite　element　simulation　results　show　that　the　Ushaped　topology　significantly　improves　the　heat　dissipation　efficiency　at　the　cold　plate　position　when　compared　to　the　parallel　channel　construction　at　that　location.　Z-shaped　topology　at　the　transmit/receive　module　cover　plate　location　offers　better　heat　dissipation　performance　than　parallel　channels　at　the　module　cover　plate　position　in　system-level　channel　construction.　Furthermore,　the　heat　dissipation　efficiency　of　the　system-level　channels　is　much　higher　than　that　of　cold　plate　cooling.