Electronics Forum | Wed Jul 09 19:05:06 EDT 2003 | randywomack
LOZ. Under-cured or out-of-spec(sloppily) applied resist is realistic. What other physics: Shiny resist surface is more prone to balls then matte finish. How about an operator eating fish & chips before handling the boards. Don't laugh... ... saw th
Electronics Forum | Mon Nov 14 10:10:52 EST 2005 | davef
When soldering your full tin (no lead) and Pb95/Sn5 solder components, you need to modify your PbSn reflow recipe to compensate for the higher melting point of the changed solder alloy [with your Sn62/Pb36/Ag2 solder paste] on those component leads.
Electronics Forum | Tue Mar 23 23:17:12 EDT 2021 | llawrence
Hello everyone, I work for a company that, up until now, has done everything using through-hole components. This has been fine for years, but we have been pushed into the world of surface mount manufacturing by a new product that is far cheaper and
Electronics Forum | Thu Apr 29 06:02:35 EDT 2021 | ttheis
Buy a good used PNP machine from a dealer in your area. There is no comparison when you are using these machines for production. Unfortunately the ddm equipment you describe is unlikely to perform any better and the time you spend trying would be bet
Electronics Forum | Thu Jul 03 18:14:03 EDT 2003 | russ
Kris, I don't know what I HAVEN'T SEEN yet cuz I haven't seen it. (HAHAHA) It is kind of like when you are looking for something and you always say after you found it that it was the last place you looked (Why would anyone keep looking for something
Electronics Forum | Thu Mar 25 20:09:35 EDT 2021 | grahamcooper22
What is the QFP pitch ? What aperture dimensions have you chosen ? Is the stencil laser cut then polished ? Your AFTER stencil size looks promising...your BEFORE stencil aperture size looks disastrous...would surely give bridges.. Your pcb pad siz
Electronics Forum | Thu Mar 25 23:23:00 EDT 2021 | llawrence
The QFP pitch is 0.5mm. Pad size is 1.475 x 0.3mm, and the new aperture size is 1.32 x 0.22mm. I'm not sure about whether or not it is lasered, but on the newly ordered stencil I selected the polishing option. Looks like the pad width is already 2/3
Electronics Forum | Fri Mar 26 15:48:31 EDT 2021 | grahamcooper22
Leaded HASL on small pads can be quite difficult to print on...the HASL tends to be domed rather than flat..and that can affect print quality...you really need a perfectly flat pcb pad to print paste on when you are assembling 0.5mm QFPs. If the pcb
Electronics Forum | Fri Aug 07 07:44:56 EDT 1998 | Earl Moon
| | | No sour grapes, | | | This has gone on too long. I expect no free advertising, nor do I seek it. It is clearly understood Bob is an industry leading consultant. What is not understood, at least by me, how he is allowed to "advertise" so freely
Electronics Forum | Thu Mar 25 19:07:22 EDT 2021 | llawrence
That is all a lot to take in, but thank you all for the recommendations. From what I understand, I'm going to start by ordering a new polished 0.1mm stencil with size reduced apertures and seeing if reduced paste deposit will help. As for the sten
