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 | 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 Apr 07 14:11:33 EDT 2022 | SMTA-69080803
@Stephen How big was the adapter board? It's challenging to depanelize and tedious to manually put these tiny assemblies in a tray.
Electronics Forum | Tue Oct 22 17:23:35 EDT 2002 | Yannick
Hi, I wondering if someone know the anwser to that. I'm using a solder paste 63/37 and on the solder joint we have a tiny little layer or flux who is like crystalin. I try to play with my profile the get it off but I don't get much success. So D
Electronics Forum | Sat Jul 29 09:10:16 EDT 2006 | davef
Ball Grid Array (BGA). A surface mount technology leadless package with the connectors to the board placed in an array on the bottom of the package. They are attached to the board with tiny balls of solder placed on each contact. Pin Grid Array (P
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 | Fri Oct 12 09:17:12 EDT 2001 | mikecampbell
Hello, I need some advice. I want to create apertures in my stencil for a IBM CCGA. I've heard the standard is 4800 cubic mils of paste per aperture. I usually use a 5mil stencil for this type of product. There is no way I'll get enough paste wit
