Electronics Forum | Mon Feb 13 10:41:14 EST 2017 | dyoungquist
Could be that your temperature ramp up rate is too fast. This could cause the flux in the solder paste to burn off too rapidly. When that happens, it can expand as it heats up and burns off, causing the solder to get spread out from the pad.
Electronics Forum | Mon Mar 07 20:27:07 EST 2005 | KEN
Oh silver and its...improved solderability over tin / copper. BS if you ask me. Look to your flux and thermal profile for wetting spread. Ask yourself just how much "wetting spread" do you need to fill a barrel? I have the same 100% barrel fill
Electronics Forum | Wed Aug 23 16:29:16 EDT 2000 | Dr. Ning-Cheng Lee
The surface tension of solder you mentioned should be referred to as interfacial tension between solder and flux. According to Antonow�s rule, the interfacial tension is the difference in surface tension of molten solder and liquid flux. Since flux a
Electronics Forum | Fri Mar 23 11:58:01 EST 2001 | mparker
You are mixing long exposed paste back into fresh? How long has your fresh jar been open to the air? You are probably doing yourself a disservice by scavenging the paste (it could have moisture entrapped). Your visocity has definitely changed. You a
Electronics Forum | Wed Apr 18 01:07:25 EDT 2001 | MW
I some something like this. My package was not flat the belly of the body rested on the PCB. We found that every 4-5 part would wander to the side. What was puzzling is that the blowers would have blown it the opposite side. ultumately we proved
Electronics Forum | Wed Dec 21 17:11:58 EST 2011 | davef
Kim: We understand what you're saying. For us, fluxing the BGA and activating the flux are the issues. * If you're squirting liquid flux under the BGA with a plastic bottle with a needle tip on it and then reflowing less than the whole board with a
Electronics Forum | Tue Oct 13 22:22:14 EDT 1998 | mike
| All Y'll | | How do you clean components that must be added to an assembled board after water wash? | | BACKGROUND | | Our basic process goes like this: | | 1 Print paste with OA flux, place, reflow, wash | 2 Repeat 1 | 3 Insert PTH, OA flux
Electronics Forum | Tue Sep 28 17:56:02 EDT 2004 | Vee Sar
Adam, I would first check hole to lead sizes on the components that you are having hole fill issues with to see that the spacing is withing spec. Second, check for oxides on lead tips, and contaminated leads that cause poor wetting and insufficient
Electronics Forum | Thu Sep 23 11:56:30 EDT 2004 | rkevin
We are printing on an assembly using SAC305 Alloy Sn96.5 Ag 3 Cu .5 with a no clean flux and getting virtually NO spread with either a ramp to spike or straight ramp profile. We are printing to standard FR4 board with immersion Ag finish. I am trying
Electronics Forum | Mon Nov 06 21:09:47 EST 2000 | Dave F
That's cool that you used the Archive. Consider running a designed experiment on your board, using your flux and solder, the limits from the Archive, and on your machine to dial in the spread in dwell numbers you see in the SMTnet Archives to your s
