Electronics Forum | Thu Aug 24 13:38:23 EDT 2000 | Dave F
It seems that sceening at -20�C and using a vibration profile similar to the one you mentioned does a good job of high-lighting defective solder connections on assembled boards, but not affecting good connections. Why is this happening? In there a
Electronics Forum | Sat Jul 29 08:52:09 EDT 2006 | davef
This recipe is nice for leaded soldering. The time above liquidous plus 20*C is too short for mixed alloy soldering. Remember all that nonleaded stuff that you add to the solder acts to increase the liquidous temperature of the alloy. Try slowing
Electronics Forum | Mon May 28 22:43:20 EDT 2007 | fazan83
You can refer to this link. http://www.merix.com/files/Lead%20Free%20Material%20Tech%20Bulletin%20Rev%20C.pdf Hope this will help.
Electronics Forum | Sat Aug 27 09:22:14 EDT 2011 | davef
It's tough to say from the picture, but it looks like the connection has not gotten hot enough to cause the solder to flow properly. What was the time above liquidous plus 20*C?
Electronics Forum | Thu Jun 28 15:38:37 EDT 2012 | davef
Matthew: That you can get solder flow when hand soldering, but not when reflow soldering, seems to be telling you that you're not getting the connection warm enough during reflow. You need to have those connections liquidous + 20*C for at least 5 sec
Electronics Forum | Mon Jan 20 22:39:46 EST 2003 | davef
Hi Stevo, Most paste suppliers say something like, �above 183*C for 45 to 60 seconds.� The problem we have with statements like that is that they seem to assume that the pads, component leads, and solder paste are all near eutectic 60/40 solder. A
Electronics Forum | Fri Nov 24 07:10:39 EST 2000 | Chris May
Sarry, Word on the street is that your profile will have to be hotter, maybe up to 20C hotter, I have trialled lead free. The sales guy said, "Right, lets reprofile your oven ! I said, "No, lets try it as it is.....! The results were fine, as the
Electronics Forum | Wed Mar 14 02:04:40 EST 2001 | pjc
zam, each paste mfg. has different "stencil life" times. check w/ your paste mfg's specification for stencil life. also, temp and humidity inside the printer's chamber effects "stencil life" time. we keep ours around 20C @ 50% RH. higher temps and l
Electronics Forum | Tue Oct 14 09:13:14 EDT 2003 | davef
To us, time above liquidous plus 20*C is more important than the 60 sec [er what ever] above 183*C [which we think is meaningless] that the fine solder paste supplier suggest. Based on what you've told us and lacking any failure analysis, we'd gue
Electronics Forum | Wed Mar 24 08:36:58 EST 2004 | Evtimov
Hi! What exatly you do? Do you reflow the both sides of the board at the same time or you reflow your second side? I think in both cases you should decrease you bottom zones. If you reflow both sides - with 10-20C(F) If you reflow the second side - w
