Electronics Forum | Fri May 29 23:11:08 EDT 2009 | isd_jwendell
Have you tried different board orientation through the oven, or have the boards been put through the same way each time?
Electronics Forum | Mon Jun 01 17:49:39 EDT 2009 | gregoryyork
Sorry looking at your profile again and considering its Aluminium substrate I would opt for an increase to the preheat or introduce a soak to the profile to get the PCB up to reflow. Try soaking between 175 - 200C sufficient enough to heat the whole
Electronics Forum | Thu Jun 04 14:35:11 EDT 2009 | floydf
We wound up using a ramp to spike profile with 50 sec. between 150C and 217C and 90 sec. above 217C. The idea being the flux is still active when it hits reflow, and it stays in reflow long enough for the weird alloy in the parts lead to wet. All par
Electronics Forum | Fri May 14 00:28:09 EDT 1999 | Mike D.
| I am seeing reflow around my signal pins after being subjected | to a profile of 204c for 1 minute and 225c for a min of 30 seconds. Signal pins are soldered into a copper plated alum. case with SB5 and then silver plated. The pins have a hot oil
Electronics Forum | Mon Jun 01 17:41:20 EDT 2009 | gregoryyork
What is your squeegee pressure and size. Also does the pad sit on a ground plane, as it looks like it is partially reflowed so surface has gone but not coallesced properly which would indicate it is more a problem with reflow above 217-219C OR obviou
Electronics Forum | Thu Oct 20 06:03:23 EDT 2005 | Slaine
during the soldering process on larger BGAs the corners can bend up or down due the large copper heatsink on top expanding quicker than the material the bga is made out of, in the worst cases this can lead to to the balls lifting out of the paste and
Electronics Forum | Fri Nov 09 19:31:43 EST 2007 | yshiau
Thank you to Dave and Scott!! What I'm delaing with is mass production test for small memory cards in volume! The reason I choose Non-operating temperature cycling is so that I can deal with volume. I can throw in quite a few memory cards in chambe
Electronics Forum | Wed Oct 03 17:07:52 EDT 2001 | davef
We have had soldering problems with fine pitch QFP in the past [and probably will in the future]. Several questions leap to mind: * When you took your profile on the component pads, do you profile on the pads that did not solder well? * When you say
Electronics Forum | Tue Sep 22 06:07:02 EDT 1998 | jacqueline coia
need advice to point me in the correct direction for solution to the problem of unsoldered joints which look soldered under normal visual inspection, but when pull strength test is performed the leads are coming away from pad, no strong intermetallic
Electronics Forum | Mon Dec 17 11:20:12 EST 2001 | slthomas
Well, I was able to convince them we had a serious problem on the poorly reflowed boards without spending 2k on off- site analysis. Now all we have to do is sort out the ones that flowed well but had solder balls (looks like a damaged stencil prob
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