Hi TechNet - I would suggest reviewing and verifying (with thermal couples) your total thermal profile of the caps as they go through the wave solder process (machine entrance to exit!). I suspect that if you compare your thermal profile data with the component suppliers data sheet that you are exceeding a maximum temperature limit during the wave soldering process. You may also have a process temperature/flux chemistry interaction. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Bowing off Tantulam Caps Author: [log in to unmask] at ccmgw1 Date: 6/9/97 10:40 AM We are facing acute problem on blowing off caps . Specifically, these caps are tantulam caps with high capacitance range of 220 MICROFARADS , rated at 10 voltage and tolerance in capacitance value is 20%.We have tried more than one vendor: one vendor was worse than the present one--however failures are always there. These caps are processed ( assembled) alongwith other tantulum caps and usually go through two heat cycles: first one on gluecure and second one at wave. The standards (temp profiles) followed at reflow and wave are as per process guidelines . These caps when tested after wave pass 100% at 5v test. Fails 20 to 25% for voltages above 7v . Dwell between wave and ATE does not matter much. Tried with and without wash -- it does not make significant difference. It is expected that the cap should pass 100% at rated voltage. Clearly there is deterioration after assembly process. we ran DOE and observed caps failing after wave. however our wave process does not seem to out of control. any one having experience on such a behaviour of Tantulum Caps -- we will appreciate your technical advise on this problem as we are running out of ideas and thinking to change process to bypass wave solder operation altogether.But that is not easy to do in short time. Please send your advise on this mail or email directly to me. [log in to unmask] Tel: 204-257-9199 *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * *************************************************************************** *************************************************************************** * TechNet mail list is provided as a service by IPC using SmartList v3.05 * *************************************************************************** * To subscribe/unsubscribe send a message <to: [log in to unmask]> * * with <subject: subscribe/unsubscribe> and no text in the body. * *************************************************************************** * If you are having a problem with the IPC TechNet forum please contact * * Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask] * ***************************************************************************