Investigation on Cu–Sn intermetallic compounds growth and signal transmission loss of the diverse copper lines after soldering in printed circuit board

The growth of IMCs at solder/substrate interface becomes more important with the sustaining advancement of integrated circuit technology. The purpose of this study was to investigate the morphology and growth kinetics of the intermetallic compounds (IMCs) formed on the diverse copper lines (including electroless copper, electroplated copper, sputtered copper) of printed circuit board under different conditions (counting isothermal aging, thermal shock and multiple reflow). And the influence of IMCs on signal integrity after isothermal aging treatment was also discussed. The results indicate that IMCs emerged on copper lines with discrepant microstructure have evident differences in morphology and thickness while the microstructure, composition and growth thickness of the IMCs naturally get changed during variational conditions. And overgrown IMCs will further aggravate the signal transmission loss for the microstrip transmission line. These interesting evolutions in IMCs introduce advantageous assistance for further investigation of solder joint reliability in electronic packaging technology.