Electronics Forum | Mon Feb 03 18:00:49 EST 2003 | slthomas
I know that the accepted (by some, although some say it may be too conservative) rule is anything less than or equal to 30 grams/square inch of surface contact area should stay on the bottom side during the second pass. How is that surface area meas
Electronics Forum | Tue Nov 20 09:50:07 EST 2007 | rgduval
Only on the bottom side? Run that side first . We usually determine our run process based on the heaviest components, and propensity for falling off during the second reflow process. If there's only the one BGA on that side of the board, we'd tend
Electronics Forum | Tue May 14 21:07:03 EDT 2002 | ianchan
Hi mates, Yes, the lighter mass is a valid reasoning. in addition to the "lighter (mass) than thou" point of view, 1) the first reason for mounting active Parts (eg. IC, QFP, LGA...) is to minimize the temperature exposure of the Parts to a single
Electronics Forum | Thu Nov 11 14:13:57 EST 1999 | Dave F
Thomas: From what you're telling us, you seem to be thinking correctly: 1 Paste should not spread appreciably in preheat 2 Something has changed, because you've not had this problem, until recently Two things to consider: 1 Has any thing changed
Electronics Forum | Sat Apr 17 17:08:22 EDT 2004 | finepitch
Russ has a hint by saying "too long of a soak at too high of a temp or being in reflow for too long/hot". I think the board should stay in the oven for 3-4 minutes, spending 60-90 seconds of which during reflow. in order to stay in the oven for 3 m
Electronics Forum | Wed Mar 24 10:04:09 EST 2004 | Marc Apell
183C, 60 +- 15 seconds). The quesiton to use a straight ramp or soak profile comes down to the product your are soldering. The key is to get the whole assembly at the same peak temp (minimized delta) and same TAL for effective formation of the so
Electronics Forum | Fri May 21 13:57:02 EDT 1999 | KA Stillings
| | hello...can somebody help me regarding the POPCORN at Reflow. What is this POPCORN at reflow, what it looks like, its cause and corrective action if there is... | | | | your help is greatly appreciated...thanks | | | | omat marasigan | | | |
Electronics Forum | Sat Oct 10 04:58:18 EDT 1998 | Tony B
| *Reply to: ericr@nj.tanon.com | | Without going into a lengthy explaination {at this time}, has anyone experimented, tested, evaluate, and/or 'perfected' an SMT double-side reflow process. Presently I'm using a Kester R593 OA (water soluble) Sn63/
Electronics Forum | Fri Feb 10 12:21:44 EST 2006 | Cal Kolokoy
DaveF is correct in saying that TAL is not the best metric to use in reflow soldering. That is why paste manufacturers give such a wide range; typically 30 to 120 seconds. The peak temperature is more important, especially in the mixed Pb and Pb-F
Electronics Forum | Thu Jun 22 11:01:54 EDT 2000 | Chrys Shea
Jason, Double sided reflow should be no problem. People have been doing it for years. The surface tension of the molten solder will hold the components on the bottom side during your second pass. This is almost always the case, unless you have re
