The　reliability　of　Sn-3.0Ag-0.5Cu　(SAC　305)　solder　joint　under　a　broad　level　of　drop　impacts　was　studied.　The　failure　performance　of　solder　joint,　failure　probability　and　failure　position　were　analyzed　under　two　shock　test　conditions,　i.e.,　1000　g　for　1　ms　and　300　g　for　2　ms.　The　stress　distribution　on　the　solder　joint　was　calculated　by　ABAQUS.　The　results　revealed　that　the　dominant　reason　was　the　tension　due　to　the　difference　in　stiffness　between　the　print　circuit　board　and　ball　grid　array,　and　the　maximum　tension　of　121.1　MPa　and　31.1　MPa,　respectively,　under　both　1000　g　or　300　g　drop　impact,　was　focused　on　the　corner　of　the　solder　joint　which　was　located　in　the　outmost　corner　of　the　solder　ball　row.　The　failure　modes　were　summarized　into　the　following　four　modes:　initiation　and　propagation　through　the　(1)　intermetallic　compound　layer,　(2)　Ni　layer,　(3)　Cu　pad,　or　(4)　Sn-matrix.　The　outmost　corner　of　the　solder　ball　row　had　a　high　failure　probability　under　both　1000　g　and　300　g　drop　impact.　The　number　of　failures　of　solder　ball　under　the　300　g　drop　impact　was　higher　than　that　under　the　1000　g　drop　impact.　The　characteristic　drop　values　for　failure　were　41　and　15,199,　respectively,　following　the　statistics.