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
Electronics Forum | Thu Mar 25 20:50:50 EDT 2021 | stephendo
A couple more things. The PCB. What size are the pads? One time a board shop had difficulty putting masking between the pads of a QFP and the pads suffered as a result. When I told them they didn't have to have masking between the pads, the pads w
Electronics Forum | Wed Mar 24 23:12:48 EDT 2021 | grahamcooper22
0.66 area aspect ratio...so for example...if the device is 0.5mm pitch QFP, the pcb pad may be 12 thou wide..make the aperture 9 to 10 thou wide...and reduce it's length by 10 % overall compared to the pcb pad.... Depending on device pitch, select ap
Electronics Forum | Thu Mar 25 09:38:36 EDT 2021 | spoiltforchoice
Well everything Graham said with some additional points.. You mention manual printing but very little about your stencil or setup. Everything you have said indicates a very limited budget has been expended, however what you have is an extreme exampl
Electronics Forum | Mon Mar 06 21:58:56 EST 2006 | kent_peterson
Good machine! Just like most part libarys don't let the operators change part profiles. Haven't seen it place 0201's but 0402's have no problem. Tape splicing for the feeders is a problem. The eject wheel gets jammed with anything other than splice t
Electronics Forum | Mon Jul 29 21:41:22 EDT 2002 | davef
Rite. Moisture, not N2, in the air is the issue.
Electronics Forum | Thu Jun 01 03:59:39 EDT 2006 | ts
there should no issues for CM402 or 301.
Electronics Forum | Tue Jun 27 12:12:05 EDT 2006 | GMan
Yes it does seem like a plating issue and analysis is being done. Thank you for your inputs.
