Higher coefficient of thermal expansion (CTE) of printed wiring board (PWB), compared with that of silicon chip, makes the impact on thermally induced stress in IC Chip by PWB a great concern for IC with Low-K inter-metaldielectric (IMD) product reliability. To characterize and validate the 65nm technology flip-chip (FC) package reliability, 20x20mm2 test chip were assembled in a 42.5x42.5 mm2 flip-chip packages for board level reliability tests, mainly temperature cycling test, mechanical bending test and mechanical shock/vibration tests. The test results showed that no Low-K and bump joint failure was found in shock/vibration test.