SL10
New Contributor
4 years agoReflow profile, time above liquidous temperature
| We found that field return units have cracked solder ball all at the ball/IC substrate interface for EPM570F256I5. Reflow profile review shows that the TL (time above liquidous temperature) was outside of the acceptable range of the solder paste (NC676, TL=93 sec actual vs 40-80 sec acceptable). However, AN353 stated range for TL is 60-150 sec. The questions are: a) does other customer have similar experience with the solder ball crack at the ball/IC interface and b) could that be correlated to the longer time above liquidous temperature. |