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 | 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 | 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 | Sun May 07 19:29:52 EDT 2006 | Dhanish
I am seeing high solder bridging for Nexlev Connector.Can someone advise what are the factors causing Solder Brdiging for Nexlev issues.
Electronics Forum | Sun Aug 01 11:39:41 EDT 2004 | Andrew
I am seeing high rate of open joint at NexLev connector and also BGA warpage issue with 52 mm Hyper BGA.anyone has the same experience?
Electronics Forum | Wed Oct 29 23:07:42 EDT 2014 | rajz
Help Needed. I face a solder bridging issue on solder mask define pad at edge only for nexlev connector . The pad design such as smd at four corner only. The bridging happen on signal to ground pin only. Current stencil we use 22 round with 6 mils s
Electronics Forum | Mon Oct 15 10:51:49 EDT 2001 | davef
On over printing, the general issues are: * Paste deposits being so large that when reflowing, collapse onto many, rather than a single solder mass. * Paste expanding during heating and being close to other solder deposits and bridging [as you say].
Electronics Forum | Tue Apr 03 01:37:54 EDT 2001 | philipreyes
60% 36% 0f ball area >36% Class2 Accept Reject 45% of ball diameter >45% 20.25% of ball area >20.25% Class3 Accept
Electronics Forum | Wed Aug 04 10:09:24 EDT 2004 | davef
We assume your opens are on the corners. If so, you are screwed. Look here: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=28669
