Copper dendrite formation on laser fuse structures of flip chip die

@article{Kho2015CopperDF,
  title={Copper dendrite formation on laser fuse structures of flip chip die},
  author={W. F. Kho and Gary H. G. Chan},
  journal={2015 IEEE 22nd International Symposium on the Physical and Failure Analysis of Integrated Circuits},
  year={2015},
  pages={565-568}
}
Copper dendrites on a flip chip die was analysed by SEM/EDX, FIB and TEM. The dendrites were found to consist of two layers. The upper layer visible under optical and SEM inspection consist of a carbon rich copper compound. TEM analysis revealed another layer under this carbon rich layer that consist of copper, tin and lead compounds. A possible mechanism of dendrite formation due to an electrochemical cell consisting of C4 bumps, copper at laser fuse structures and a moisture or flux… CONTINUE READING