Silver-Copper-Palladium　(Ag-Cu-Pd)　brazing　alloy　is　an　important　material　used　for　vacuum　electronic　devices　packaging　for　its　low　vapor　pressure,　good　air　tightness,　excellent　wetting　property,　and　mechanical　properties.　The　Ag-Cu-Pd　brazing　alloys　are　proposed　for　the　vacuum　electronic　devices　packaging　in　these　few　years.　Ag-Cu-Pd　alloy　is　one　of　the　common　mid-temperature　and　high-temperature　brazing　alloys　used　in　multiple　temperature　gradients　soldering　as　present.　In　the　current　study,　three　Ag-Cu-Pd　brazing　alloys　with　different　components　were　designed　for　multiple　temperature　gradient　soldering.　The　Ag-Cu-Pd　brazing　alloys　were　prepared　by　means　of　vacuum　induction　melting.　In　order　to　obtain　thin　Ag-Cu-Pd　alloy　strips,　the　ingots　were　melted　and　injected　onto　a　copper　roller　rolling　at　high　speed　(i.e.,　melt　spinning).　The　obtained　thin　strips　were　used　for　soldering.　The　phase　constitution,　solidliquid　phase　transition　temperatures,　microstructures,　elemental　distribution　and　wetting　property　of　the　Ag-Cu-Pd　solder　alloys　on　copper　were　investigated.　Melting　behavior　of　three　Ag-Cu-Pd　brazing　alloys　with　different　components　were　tested　using　Differential　Scanning　Calorimetry,　the　liquidus　were　990°C,　890°C　and　846°C.　The　Ag-Cu-Pd　brazing　alloys　were　soldered　with　copper　substrates　at　different　temperatures　for　different　periods　of　time.　The　spreading　areas　for　all　Ag-Cu-Pd　brazing　alloys　on　copper　were　in　the　range　of　220-460　mm2,　the　wetting　angles　were　in　the　range　of　12-24°,　which　indicate　the　good　wettability　of　Ag-Cu-Pd　alloys　on　copper.　The　Cu/Ag-Cu-Pd　solder　joints　were　examined　with　Scanning　Electron　Microscope　and　Electron　Dispersive　X-ray　analysis.　In　this　study,　the　proper　vacuum　electronic　devices　brazing　components　and　optimal　brazing　parameters　are　obtained,　which　could　be　potentially　applied　for　practical　applications.　©　2014　IEEE.