Numerous　electronic　system　failures　have　been　attributed　to　short　circuits　caused　by　metal　whiskers　that　bridged　closely　spaced　circuit　elements　when　they　were　maintained　in　a　high-current-density　environment.　Typically,　in　single-phase　interconnect　materials,　atoms　are　driven　from　the　cathode　to　the　anode　and　a　compressive　stress　can　build　up　at　the　anode　end　of　the　stripe,　which　can　induce　the　formation　of　whiskers　and　hillocks.　However,　the　electronic　solders　used　in　interconnects　are　multiphase　materials　where　primary　and　secondary　diffusion　atoms/ions　exist.　In　order　to　accelerate　the　growth　of　whiskers　and　hillocks,　a　high　current　density　(10(4)　A/cm(2))　combined　with　high　ambient　temperatures　(80A　degrees　C)　was　applied　to　eutectic　Sn-Bi　solder　joints.　Metal　whiskers　and　hillocks　were　observed　on　the　overflowed　solder　film　above　the　Cu　substrate.　However,　in　the　absence　of　the　electric　field,　metal　whiskers　and　hillocks　could　also　be　squeezed　out　from　the　solder　reaction　films　after　several　days　of　isothermal　aging　(125A　degrees　C),　demonstrating　that　the　chemical　reaction　between　Sn　atoms　and　Cu　atoms　can　provide　the　driving　force　for　the　formation　and　growth　of　metal　whiskers　and　hillocks.