Electronics Forum | Tue Feb 06 23:01:44 EST 2007 | Wayne
The QFN is found to have contact problem during FCT. The paste that I am currently using is SnPb 63/37 water soluble paste. Is it because of water soluble paste? (unable to clean after reflow process as QFN is entrapped by paste/flux) Should we use
Electronics Forum | Wed Feb 07 09:37:48 EST 2007 | billyd
Had the very same thing happen the first time we used the small QFNs. The aperture for the thermal pad in the center needs to be cut in a grid form, either squares (with around a 10 mil spacing between openings) or circles, like a BGA pattern. Too mu
Electronics Forum | Wed Feb 07 07:45:50 EST 2007 | jax
Water soluble residues probably won't cause instant failures. The failures are most likely caused by excess paste being deposited on the center pad of the QFN. The excess solder keeps the part from sitting down in reflow and increases the possibility
Electronics Forum | Fri Sep 24 07:31:13 EDT 2021 | mun4o
Hi all, our company planning to buy a new /third/ smd line.I have choose P&P ,and solder paste printer , but I hesitate about reflow oven.Now we have two smd lines.The first oven is a old ersa hotfow5 - very robust machine. The second reflow oven is
Electronics Forum | Thu Dec 14 04:42:11 EST 2017 | jineshjpr
Can anybody suggest how can I achieve good solderability in convectional reflow oven If I reduced Convection Air Speed 80%. The whole purpose is to reduce 0402 LED tilting in the convectional reflow and the PCB having QFN with 60 to 120 sec soak, 30
Electronics Forum | Fri Apr 06 11:01:34 EDT 2012 | umairzameer
Agree with Reese with my experience with QFN parts it is the reflow.
Electronics Forum | Thu Jul 05 13:47:10 EDT 2007 | arun2382
QFN assembled on a PCB indicates paramteric fails when tested. When the QFN on PCB is reflowed a second time, it recovers and passes testing. Visual, X-ray inspection revealed no anomalies. Cross-section images of solder joint revealed no anomalies (
Electronics Forum | Mon Mar 11 03:40:18 EDT 2019 | jineshjpr
BOT SIDE QFN DROP DURING TOP SIDE REFLOW; Bot & Top side solder profile temperatures are almost similar with a 5 Deg variation
Electronics Forum | Thu Mar 29 02:46:25 EDT 2012 | johndoe0222
My company is doing a project with a lot of QFN. The question that we are not sure is how to properly solder a QFN on a PCB. QA says The alignment tab on the side of the QFN should have a physical solder from the board, like a leaded chip. After refl
Electronics Forum | Wed Feb 13 10:53:58 EST 2019 | pace_worldwide
The TF2800 features a much more powerful 1900W bottom-side preheater which incorporates 7 independently activated (via software) IR emitters. The preheater is also height adjustable to allow it to get closer to the pcb to provide more aggressive ther
