Electronics Forum | Wed Jan 22 13:17:48 EST 2003 | slthomas
We're considering stenciling SMT adhesive to increase throughput. This is an as-of-yet unproven process and for that matter pcb design (we've never done anything with more than about 50 SMT parts on the bottom, this board has in excess of 1200, but
Electronics Forum | Fri Mar 12 18:12:15 EST 1999 | B. Walton
Spray cleaners are poor alternatives to todays ultrasonic stencil cleaners. Ultrasonics are the way to go and you can use rather benign water based chemistries to get the job done. As for screening adhesives and cleaning glue residue with spray wands
Electronics Forum | Wed Jul 27 09:58:05 EDT 2011 | davef
Pressure printing systems Conventional stencil printing techniques have fundamental limitations as regards paste handling: The volume of paste available for printing is limited, so frequent replenishment is necessary Paste is difficult to c
Electronics Forum | Sun Aug 15 14:56:03 EDT 1999 | Dean
| One of the DFM suggestions I've seen is to remove the solder mask web, i.e. the mask between pads on 20-mil QFP devices. The rational is that if the mask is thicker than the pad the mask can prevent the stencil from making intimate contact with th
Electronics Forum | Wed Dec 18 15:38:59 EST 2002 | swagner
I have had a similar problem in the past, since I have never worked with a semiautomatic printer there could be a few things I recommend that will not work for you. 1. Make absolutly sure that you have proper support under all of the BGA's. 2. Print
Electronics Forum | Mon Mar 04 17:52:59 EST 2002 | davef
Yes, providing the surface of the via is solderable. * If so, how much paste? => Vias come in various sizes. Boards vary in thickness. So, the amount of paste to fill a via varies. Roughly, you�ll need twice as much paste as the volume of the via
Electronics Forum | Thu May 30 10:31:03 EDT 2002 | robbied
Hi Yannick. This is an issue that we are just recently getting into but here is some ifo that I have gathered so far. I have seen/ used 2 different rework machines. The one we have bought is a 'PACE TF2000' which was at the lower cost end of the mar
Electronics Forum | Fri Jun 02 17:33:51 EDT 2000 | Dave F
Hey CK, we�re all sodder googoo�s ... wanna be gurus Why donchu tell �em not to put sodder in your vias? Er, makit so the sodder won�t flow out of the bottom of the vias and cause dem stalactites? OK OK, here�s wacha do, modify the second side ste
Electronics Forum | Fri Feb 11 09:48:56 EST 2000 | Christopher Lampron
Dear Masdi, Solder beading (as opposed to solder balls) is usually caused by volume of solder paste, displacement of solder paste when component is placed and sometimes the proximity of the solder depositions for that component. Basically, a small a
Electronics Forum | Tue Jan 25 09:15:02 EST 2005 | Marc A
Good info, thanks for passing along. The company I work for (equipment supplier) ran some tests with lead free material in air and N2 environements for reflow. In the air reflow environement it was noticed that the material does not spread, much li
