With　the　trends　of　hi-her　integration　and　microminiaturization　in　electronic　packaging,　the　sizes　of　the　soldered　Joints　are　becoming　smaller　and　smaller.　The　corresponding　current　density　in　the　soldered　joints　can　easily　reach　10(3)A/cm(2)　or　higher,　which　makes　the　electromigration　(EM)　much　more　prominent.　EM　will　lead　to　the　atoms　to　pile　up　at,　the　anode　side　and　produce　voids　or　cracks　at　the　cathode　side.　Furthermore,　with　the　stressing　time　increasing,　these　voids　or　cracks　will　propagate　gradually　resulting　in　the　soldered　joint　rupture.　EM　may　induce　whisker　growth　resulting　in　the　short　circuit.　All　these　defects　can　degrade　the　reliability　of　the　soldered　joints.　In　this　paper,　the　effect　of　electric　current　(5　x　10(3)　A/cm(2),　80　degrees　C)　on　the　whisker　and　hillock　growth　in　Cu/Sn-58Bi/Cu　soldered　joint　was　investigated　by　SEM　and　EDS.　It　was　found　that　after　current　stressing　for　540　h　the　solder　at　the　cathode　side　is　depleted　and　whiskers　appear　in　the　depleted　zone,　while　solder　film　forms　on　the　Cu　substrate　at　the　anode　side　and　a　large　number　of　whiskers　and　hillocks　appear　on　the　film.　EDS　revealed　that　these　whiskers　and　hillocks　are　mixtures　of　Sn　and　Bi.　When　the　stressing　time　reached　630　h,　more　whiskers　and　hillocks　form　and　more　amounts　Of　Cu6Sn5　intermetallics　form　at　the　interface　of　solder　and　cathode.　The　above　facts　indicated　that　the　electromigration　may　induce　diffusion　and　migration　of　metal　atoms,　leading　to　formation　of　a　thin　solder　film　on　the　anodic　Cu　substrate.　The　compressive　stress　generated　by　intermetallics　formation　provides　a　driving　force　for　whisker　and　hillock　growth　on　the　solder　film,　and　the　Joule　heating　should　be　responsible　for　the　whisker　growth　at　the　cathode　side.　There　is　no　credible　approach　for　predicting　the　whisker　growth　time,　growth　velocity　and　whisker　length　although　several　mechanisms　have　been　proposed,　but　are　not　universally　accepted.　By　general　consensus,　compressive　stress　is　recognized　as　the　main　driving　force　for　whisker　growth　and　a　break　of　the　protective　oxide　on　the　surface.