Electronics Forum | Tue Apr 09 00:09:25 EDT 2002 | craigj
Question. When profiling and looking at the profiles cooling rate. Over what temperature range should the slope be monitored and what sort of cooling rates should be looked for. Paste supplier says no more than 6degC per sec, some components maybe lo
Electronics Forum | Tue Apr 09 07:41:08 EDT 2002 | johnw
Craig, it depend's n what you want to look at. In term's of te gran structure of the solder jont that's formed when the joint is cooling so you'd want to monitor the temperature drop from the peak or say 215dg C for ref down to probably about 150 an
Electronics Forum | Thu Apr 11 13:37:54 EDT 2002 | davef
John, I would not INTENTIONALLY steer you wrong [most of the time]. But this is just a GREAT example of how we learn something and take it to mean something, only later to learn that while what we learned is true, it means something else.
Electronics Forum | Thu Apr 11 11:26:34 EDT 2002 | johnw
Dave, I sand corrected since I know you wouldn't steer me wrong...although the lst time I looked at the IPC spec for a solder profiel it was still designed for older generations of paste and were specifically water wash biased although that doesn't c
Electronics Forum | Tue Apr 09 08:44:43 EDT 2002 | davef
Read IPC-7530 "Guidelines for Temperature Profiling for Mass Soldering Processes (Reflow & Wave)". There is no advantage in dropping off much faster than 4�C/sec. In fact, you risk fracturing your newly formed solder connections due to board warping
Electronics Forum | Tue Apr 09 08:49:43 EDT 2002 | davef
Hey Bud. Allow me to 'turn' your point about 'grain structure' just a bit. Fast cooling rates / coarse grain structures was a bit of red herring in the early 80's. Faster cooling DOES produce finer grained solder connections. Accelerated testing of
Electronics Forum | Fri Jul 09 07:14:36 EDT 2010 | cobar
http://www.shanelo.co.za/reflow_profile_adjustment.htm http://www.shanelo.co.za/how_to_profile_a_pcb.htm http://www.shanelo.co.za/SMD%20Assist.htm
Electronics Forum | Mon Jul 12 04:52:50 EDT 2010 | cksam
Thanks for the information about the reflow profiling its really useful for me to set up my own profile.
Electronics Forum | Tue Jul 06 00:23:11 EDT 2010 | cksam
I am doing the case study of the component chip 0201 tombstoning problem. The significant causes was the reflow profiling preheat slope or ramp up rate. I really can't differential between preheat slope and ramp up rate. Could anyone here show me the
Electronics Forum | Mon Jul 12 05:01:30 EDT 2010 | cobar
Please follow the paste suppliers specs for the paste as an indicator.Most people think that if they follow the paste suppliers recommendations to the T it will be a perfect profile but this is not the case.Play around with preheat settings but follo
