As　the　designs　of　electronic　products　were　tended　to　be　miniaturized　and　highly　integrated,　the　electromigration　of　solder　joints　becomes　a　major　issue　due　to　the　increasing　current　density.　It　is　demonstrated　that,　the　electromigration　effect　of　solder　joints　could　induce　the　microstructure　evolution　and　failure　in　solders　at　high　current　densities.　At　the　same　time,　a　large　quantity　of　Joule　heat　generated　during　electromigration,　which　leads　to　non-uniform　distribution　of　temperature　and　thermal　migration.　Electromigration　and　thermal　migration　are　the　main　factors　that　cause　solder　joint　failure.　The　aim　of　this　paper　is　to　explore　the　hetero-connecting　materials　effect　on　SnBi　solder　joints　under　the　effects　of　electrical　and　thermal　field.　The　linear　Sn58Bi　solder　joints　which　have　different　substrates　were　utilized　in　this　paper.　The　peak　reflow　temperature　for　soldering　was　205°C.　The　differences　of　the　main　element　migration　between　the　Cu/Ni　joints　and　the　Cu/Cu　joints　were　compared　and　the　failure　behavior　of　each　structure　above　was　discussed,　respectively.　The　morphology　and　element　distribution　were　characterized　by　SEM　and　EDX　analysis.　It　is　showed　that　the　migration　of　Cu　atoms　was　retarded　and　Cu　atoms　rarely　appeared　inside　of　the　solder　joints　of　Cu/SnBi/Cu.　On　the　other　hand,　Cu　atoms　were　migrated　significantly　faster　than　Bi　atoms,　in　Cu/Sn58Bi/Ni　solder　joints.　The　reason　of　that　was　Cu/SnBi/Ni　solder　joints　had　a　stable　IMC　(Cu,　Ni)6Sn5　due　to　the　Ni　atoms　migrating　to　the　solder　joints　from　the　substrate,　which　suppressed　the　crack　propagation　and　cracking　of　Cu6Sn5,　and　thus　effectively　delayed　failure　behaviors　compared　to　Cu/SnBi/Cu　solder　joints.　©　2018　IEEE.