Electronics Forum | Tue Feb 11 10:41:30 EST 2020 | dunks
We had this problem at my old job. My understanding (from googling this problem previously) is that the exposed leads on the side of the qfn are not tinned and are not required/designed to have a fillet. Someone correct me if I'm spouting lies.
Electronics Forum | Sun Feb 23 21:19:08 EST 2020 | sssamw
Yes, this is for tin-lead profile. And for the QFN pins which has copper exposed that not required and not possible to have fillet on side surface as in IPC, see 8.3.13, in IPC-A-610-G
Electronics Forum | Thu Oct 14 16:38:29 EDT 2021 | SMTA-64387687
OSP is there to keep the copper from oxidizing. Once you wash the board, the copper is exposed. So, you have to either use it right away, or store it in a non-oxygen environment (vacuum/nitrogen).
Electronics Forum | Fri Jun 10 17:55:16 EDT 2022 | jdengler
Generally we overprint on the exposed part of these pads. When there isn't enough clearance at the end of the pad we place solder preforms with the placement machine. Jerry
Electronics Forum | Fri Dec 09 22:06:44 EST 2022 | smith88
Are there standards that dictate how long a EEE component can be exposed outside of a nitrogen bag before oxidation occurs? Since Covid I am seeing more and more caps and resistors that seem to have oxidation and do not solder well....
Electronics Forum | Thu Jul 19 21:55:14 EDT 2001 | davef
You're correct, but you need to take it a little bit further. Installed correctly, ExposedPad� TSSOP IC packages significantly increase the thermal efficiency of power constrained standard TSSOP packages. This can increase heat dissipation by as mu
Electronics Forum | Thu Jul 29 23:21:51 EDT 1999 | CH Lee
I received a request from customer to assemble ceramic substrate (alumina oxide)that printed with a low temperature Copper thick film conductor (the overglaze layer is polymer). The Copper pads are exposed without any coating. This ceramic substrate
Electronics Forum | Thu Sep 12 11:50:58 EDT 2002 | stepheno
http://www.jedec.org/download/search/jstd020b.pdf http://www.jedec.org/download/search/jstd033a.pdf The above links are for JEDEC standards regarding moisture sensitivity. SMT magazine has an article a few months ago regarding a company that saved
Electronics Forum | Wed Oct 19 07:44:33 EDT 2005 | davef
When a hole is drilled during board fabrication, it can transfer resin from the base material (eg, FR4 core or prepreg) to cover the exposed edge of conductive material in the wall of a drilled hole. This is called resin smear. Etchback is a control
Electronics Forum | Wed Oct 26 20:20:28 EDT 2011 | machinehead
Our Company is suffering a Huge lose in scrap parts. I recently took over the My12 MyData SMT Machine. And I'm trying to find a remedy to the lose of exposed parts when pulling tape out of feeders. I've tryed alot of things? But still no Luck. I'm lo
