Electronics Forum | Fri Jan 24 11:05:38 EST 2003 | johnw
I fyour just using Sn/Pb in your paste even using nitrogen will lave you with slightly grainy joints. The silver from your PCB will disolve into the Sn/Pb at 'uncontrolled' rate what I mean is depending on the temperature and time above liquidous the
Electronics Forum | Mon Mar 29 14:58:08 EST 2004 | davef
Josh: Final cure of the LPI solder mask: 310*F for 45 minutes. Your board fabricator needs to do a better job. Most fabs do not check cure, because the processes subsequent to cure are so brutal that the fab expects the following process to highlig
Electronics Forum | Tue Sep 01 02:57:42 EDT 2009 | d0min0
davef As for the repair : - with hot air blower it is not possible (you can melt, but it will not wet) - with standard iron - no problem to repair (no additional material is needed) isd.jwendell yes, the profile is checked on those places (same si
Electronics Forum | Mon Apr 15 10:32:23 EDT 2019 | slthomas
Just a comment on the Heller 1500. We had 3 at a previous workplace where we never made the Pb-free transition (this was early 2000's). The ovens we had were not designed for and were never used for Pb-free processing yet every one of them had all o
Electronics Forum | Mon Aug 31 07:56:39 EDT 2009 | d0min0
Hello, since some days we are facing strange problem with SMT component reflow paste on one side of the component is reflowed correctly while the other side is 10%-70% non-reflowed (same component on 3 positions per module, alwyas the same land pad)
Electronics Forum | Wed Oct 19 07:04:06 EDT 2022 | winston_one
If any changes in design is not possible and you have to solder it, it's a real headache, I know... I see only 3 options here that you can try consiquently: 1) Accurately profile the board and optimize a profile (go to lower limit of process windo
Electronics Forum | Thu Jan 11 22:01:09 EST 2007 | davef
Joe: I know this is not the correct forum to post chip "reworking" questions. Reply: Rework questions are as appropriate as the next topic here on SMTnet J: BGA will not reflow at any normal temperature level. I believe these chips may have been gen
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 | Tue Dec 28 12:55:16 EST 1999 | Justin Medernach
Greg, The best advice that I can give you is a PBGA will respond just like any other surface mount package. There may be a 5 degree delta between a PBGA 356 and a QFP208 but the two respond very similarly in the convection reflow environment. CBGAs
Electronics Forum | Tue Jul 28 17:37:00 EDT 1998 | Robert Steltman
| Here is what I would do faced with your problem. First I would profile a similar board or use an existing profile. From there I would place the dummy device on the surface of a sample board with a thin thermocouple soldered to the board surface und
