Electronics Forum | Mon Feb 20 20:57:35 EST 2006 | Cal Kolokoy
The ramp sets the stage for flux activation, and if ramping in a linear fashion, burning off some of the volatiles, but yet preserving the activators. The ramp is also intended to preheat the SMDs to prevent thermal shock. Most solder paste data sh
Electronics Forum | Tue Dec 18 16:49:17 EST 2001 | davef
J-STD-001 - Requirements For Soldered Electrical & Electronis Assemblies is the governing document. It defines no specific limits like you mention. It states words to the effect that preheating should not do bad things.
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 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 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 | Tue Jan 30 01:06:51 EST 2018 | dgassier81
Hi, In our shop we've always baked out PCBs and moisture sensitive parts prior to electronic assembly using a gentle ramp rate of 2 degC/minutes going hot (93degC) and same ramp rate going cold (back to room temp). We're trying to outsource that pro
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 | Sat Apr 14 00:04:21 EDT 2001 | zam_bri
I'm not a Wave soldering guy and my friend have asked me a question on what is the best preheat time and temperature for Wave soldering.They experiences only 10% flow up thru the PTH barrel. I've asked them to increase the temperatue to 120 Deg C. Cu
Electronics Forum | Mon Apr 16 12:59:51 EDT 2001 | Mike R
If you will place a temperature strip on the board during wave soldering process you will get a max of 210 F or 98.8 C which is normal on the standard wave temperature. The problem on the 10% solder on the TH via hole can be caused by insufficient fl
Electronics Forum | Sat Apr 14 03:25:04 EDT 2001 | kpliew
Hi , As far as I experienced with wave reflow. If u have a refective thermal reader , u will see that the board is exposed to much more temp than the 120 deg that u set. Actually , once u see the board warp or comp. crack u should know that
