Electronics Forum | Fri Dec 17 16:23:22 EST 1999 | Mike Naddra
Hello Henry, Tombstoning is caused (In most cases) by a force imbalance on either side of the component. As the solder becomes liquidous the surface tension of the liquid will pull the component to the center of the liquidous area. To solve the probl
Electronics Forum | Mon Mar 11 11:11:38 EST 2002 | slthomas
Tahnk you for posting the charts. > > They look > very useful, but I have a silly question: In > reflow problems _ What is "leaching" ? Dissolution of the component metallisation into the liquid solder. _ > What is "Halo effect" ? "...a
Electronics Forum | Mon Aug 19 20:45:31 EDT 2002 | davef
Bob Willis and Phil Zarrow have had a running commentary on the ability of reflowed solder to hold components on the bottom side during reflow. You can find references to their component weight to pad area rations in the fine SMTnet Archives. The
Electronics Forum | Tue Mar 21 21:03:55 EST 2006 | davef
1 Chatter about mask opening � No BIG problems with these statements. It�s just that you may need to tailor your reflow recipe to minimize these escapees. 2 Stencil design - Any area ratio below 0.66 is going to very challenging to print, as you ca
Electronics Forum | Tue Aug 03 17:44:34 EDT 1999 | Earl Moon
| We're getting field failures in a high impedance portion of the circuit. Think the unpopulated pc card has contaminates because we were able to grow dendrites by applying a 9 volt battery across the suspected pad, placed a drop of de-ionized water
Electronics Forum | Fri Sep 21 10:44:34 EDT 2001 | slthomas
You can, and for small parts you probably won't see much difference between body temp. and lead temp. For QFPs or PLCCs there will be a much greater delta, though. I'd be more concerned with the small surface area you're making contact on (spherica
Electronics Forum | Thu Aug 28 11:31:17 EDT 2008 | patrickbruneel
Matt solder mask finishes gives the widest process window in view of potential amount of residues when using No-Clean. Shiny (glass like) finishes are more sensitive to residues due to lower surface area compared to matt finish. If the shiny finish i
Electronics Forum | Mon Aug 19 11:36:27 EDT 2019 | bulur
How does no-clean flux residues on a PCB assembly impact the ROSE testing? Does no-clean flux residues on the PCBA dissolve in solution of ROSE tester and increase ionic contaminants level in terms of NaCl per surface area? Is ROSE tester solution (a
Electronics Forum | Wed Jul 29 17:43:26 EDT 1998 | Steve A
| Hi, good friends | I found this site is so wonderful to learn SMT techniques meaningfully. | We now employ 3 Fuji GL-541 dispensors and raw material with Soma IR-120. but we found glue string casually. From my experience from trouble-shooting the c
Electronics Forum | Thu Oct 19 12:34:36 EDT 2000 | lwatson
I can't seem to find an article about the limiting mass of a SMT component on the solderside of a double-sided reflowed PCB. I'm pretty sure that Phil Zarrow did an article on this subject. It went something like the mass/land surface area?
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