The　indium-based　solders　and　bismuth-based　solders　are　commonly　employed　in　soldering　the　thermopile.　Since　the　wettability　between　bismuth　telluride　materials　and　low　melting　point　alloy　solders　is　poor,　a　nickel　layer　was　employed　on　the　surface　of　thermoelectric　materials.　In　this　study,　in　the　atmospheric　environment,　the　eutectic　Sn-Bi　and　Sn-In　solders　spreaded　on　the　p-type　thermoelectric　respectively　without　using　soldering　flux,　the　corresponding　interfacial　microstructures　were　indentified.　The　interfacial　reaction　is　more　sufficient　under　300　°C　when　comparing　to　that　under　250　°C.　In　addition,　a　thin　nickel　layer　was　deposited　on　the　thermoelectric　unit　by　vapor　deposition　facility.　However,　a　thin　Ni-plated　layer　on　thermoelectric　materials　might　induce　severe　formation　of　cracks.　©　2011　IEEE.