Electronics Forum | Fri Aug 11 05:22:55 EDT 2023 | compit
you can put BEFORE the connector so-called preforms - if the connector falls over, enlarge the pads under the connector and place the preforms next to the leads
Electronics Forum | Fri Aug 11 13:38:52 EDT 2023 | lauri
We have a Contact 3AV pick and place and we can't get the table to home. Any solutions?
Electronics Forum | Mon Aug 14 05:45:16 EDT 2023 | dimamalin
First, this is the result of bad printer setup. Adjust knife pressure, PCB gap, separation speed, tooling, and stencil cleaning. Pay attention to the coating of contacts pad and height of solder mask of PCB.
Electronics Forum | Mon Aug 14 13:08:00 EDT 2023 | dimamalin
Similar issues arose for me in cases where the contact pads of components were located below the solder mask level. Ordering a thinner stencil might potentially solve the problem.
Electronics Forum | Mon Aug 14 13:21:48 EDT 2023 | calebcsmt
the implication being the soldermask is too thick, raising the top of the board higher than the pads themselves (eliminating gasketing)? Essentially, the board isn't perfectly planar would be the subject of cause it sounds like?
Electronics Forum | Mon Aug 14 13:51:37 EDT 2023 | calebcsmt
I'm actually currently in the process of discussing with stencil MFG regarding the apertures and reduction to see if perhaps it was not optimal for this fine pitch QFN, as just as you mentioned, we have similar products with similar QFNs that do not
Electronics Forum | Mon Aug 14 14:17:19 EDT 2023 | emeto
Now you have to find the root cause, before you continue. Is it PCB design or printer setup? Or both contribute?
Electronics Forum | Tue Aug 15 14:32:23 EDT 2023 | emeto
I think this part has terrible thermal balance. I assume in reflow process the part is bending so much that it will cause the shorts you see. I would suggest you get one of these beautiful hi temp cameras and record the reflow process. This video sho
Electronics Forum | Tue Aug 15 17:17:26 EDT 2023 | emeto
This one picture would help us so much to assess. Step stencil to 6mil for the connector area.If this doe not resolve it, start thinking about part contamination, insufficient heat in reflow profile and a few other
Electronics Forum | Thu Aug 17 12:48:40 EDT 2023 | denism
Measure the temperature of the central and edge balls. There should be minimal difference in peak temperature and TAL offset. If not, correct reflow profile. For correct reflow profile your BGA mus be backed befor use.
