The　work　studies　the　vibration　lifetime　modeling　of　Sn37Pb　soldered　plastic　ball　grid　array　(PBGA)　assemblies　on　the　basis　of　vibration　tests,　finite　element　analysis　(FEA)　and　Steinberg＇s　empirical　formulation.　The　test　vehicles　for　the　vibration　tests　consist　of　twelve　PBGA　components　with　built-in　daisy-chained　circuits,　which　are　assembled　on　a　printed　circuit　board　(PCB)　symmetrically.　First,　the　natural　frequencies　of　the　test　vehicle　were　determined　by　modal　tests.　The　first　three　natural　frequencies　were　obtained　using　FEA,　which　were　compared　with　those　from　the　modal　test.　Then,　narrow-band　sinusoid　vibration　tests　were　conducted　at　the　first　natural　frequency　of　the　test　vehicle　using　constant-amplitude　excitation,　and　the　number　of　failure　cycles　was　recorded　by　monitoring　the　overall　electrical　resistance.　FEA　was　performed　to　obtain　the　stress　of　the　critical　solder　joints　under　various　levels　of　sinusoidal　vibration　loadings.　To　construct　the　stress　versus　failure　cycles　(S-N)　curve　of　the　solder　joints,　the　stresses　of　solder　joints　were　used　in　conjunction　with　the　lifetime　obtained　from　the　sinusoidal　vibration　tests.　The　random　vibration　test　was　conducted　on　the　test　vehicle　to　assess　the　lifetime　of　the　solder　joints　subjected　to　broad-band　excitation.　Random　vibration　analyses　were　performed　numerically　to　obtain　the　displacement　responses　of　the　PBGA　assembly.　Finally,　a　fatigue　life　prediction　based　on　Steinberg＇s　model　was　deduced　from　all　these　procedures.　A　comparison　of　the　lifetime　between　the　experimental　results　and　the　prediction　suggests　that　the　methodology　is　valid　and　practicable　in　predicting　the　vibration　lifetime　of　PBGA　solder　joints.