Electronics Forum | Fri Sep 14 14:20:23 EDT 2007 | sjcdcheu
What is the surface finished of your board and what is the peak temp at your solder joint?
Electronics Forum | Wed Jan 14 10:07:38 EST 2004 | Patrick
More on QFP soldering issue as per Paul f original e-mail. 1. Problems occured on different PCB's, on different lines using different equipment 2. Flux residue is common in the dimple on the solder. 3. The fault occurred using both "Kester 265" & "Al
Electronics Forum | Mon Sep 10 18:04:28 EDT 2007 | slthomas
How are you attaching your thermocouples to measure the temperature of the lead/pad connection?
Electronics Forum | Tue Sep 25 14:43:28 EDT 2007 | mun4o
Hi, we change Kester with Interflux and all it is OK.The problem was paste Regards
Electronics Forum | Thu Jan 08 16:21:18 EST 2004 | Dean
Oh I forgot...is this product wave soldered? Opens can occur if your wave preheat and dwell are not controlled. I ran into this years ago....wild situation. Good luck
Electronics Forum | Thu Jan 15 08:39:26 EST 2004 | Patrick
Thanks for the reply, I do know that the HASL finish is "domed " on opposite sides of a QFP site & "smooth" on the other two sides. (ie. Sides 1 & 3 are domed, & sides 2 & 4 are smooth ) depending on the direction the PCB was extracted from sol
Electronics Forum | Wed Sep 05 07:07:25 EDT 2007 | mun4o
hi, I have a big problem with soldering uP QFP144 package.All components in PCB are small, only this chip is big and I can't make good temperature profile.Solder joints of other components are shining and with good wetting, but in QFP leads solder j
Electronics Forum | Wed Jan 14 12:38:59 EST 2004 | Chris Lampron
Good Day, I have had a similar situation with a QFP. It turns out that the PCB HASL finish was too thin causing oxidation on the copper. The problem was only evident on the QFP as this part had the smallest deposition of paste (and therefore, flux)
Electronics Forum | Tue Jan 13 22:43:11 EST 2004 | davef
We have seen this in reflowed parts, where there is flux res collected in the dimple in the solder, where the lead 'presses' in the solder. Generally, we attack this as a thermal issue: * Thermal pads sucking the heat away from the leads. * Leads no
Electronics Forum | Tue Jan 13 01:20:31 EST 2004 | mantis
Hi All, I have seen this issue on a QFP160.Firts of all as previously suggested if the board is wave solderded make sure that you are not seeing topside reflow as the board goes over the wave.Secondly you should verify your reflow profile.I seen this
