Electronics Forum | Sun Feb 07 10:51:09 EST 2010 | davef
The ratio of aperture opening area to aperture wall area is a critical evaluation measure for the release of the printed solder paste. The stencil thickness has the biggest impact on area ratio.
Electronics Forum | Mon May 06 11:45:32 EDT 2019 | slthomas
There are quite a few papers out there on the subject. Just enter "SMT void reduction" into google or other search engine and take your pick. That said, slow ramp rates and paste volume reduction are a good place to start. Although I haven't tried i
Electronics Forum | Mon Nov 16 12:41:46 EST 1998 | MMurphy
| | | | | I keep hearing about polyimide stencils, but what are they like in terms of registration and aperture accuracy? | | | | | | | | | Fraser- | | | | | | | | We use polyimide stencils with great success for our prototype boards. They are
Electronics Forum | Fri Jul 30 17:13:30 EDT 1999 | Dave F
| | | Looking for solder paste specification limits which have reliability data to support them. Currently, we are looking to define the min/max volume necessary to ensure a good joint on CBGA, PBGA, and Micro-BGA's. Any information will be greatly
Electronics Forum | Thu May 17 07:36:40 EDT 2001 | Bob Willis
Here is a copy of a draft document on PIHR Inspection I have jotted down on a flight to Scotland yesterday, any comments suggestions etc ? I have already most of the photos for the standard but as you know there is nothing in the IPC document it just
Electronics Forum | Thu Aug 05 05:23:13 EDT 2004 | Bryan
Hi All,per my understanding ,the fail mode is the heel fillet of QFP seems no good,right?If yes...I think..we should:1.increase the aperture length on stencil and make sure there's enough solder paste on pad before reflow. or you can increase your t
Electronics Forum | Fri Mar 02 10:06:28 EST 2007 | oldsmtdude
Agilent SP50 rocks for continuous improvement and pass-fail efforts. You'll see variation you never imagined you had prior. But be aware you absolutely have to monitor data and tweak your processes to improve results. Do not jump in and try and use
Electronics Forum | Mon May 12 15:13:29 EDT 2014 | emeto
Thank you guys. As we are speaking I keep examine the problem and here is what I got so far. 1. I measured the temperatures on my profile and the lead is hotter than the board. The lead goes 12 seconds earlier than the pad and is taking the solder.
Electronics Forum | Wed Nov 21 12:29:52 EST 2001 | mparker
Now that we know where you've been and what you wish to accomplish next, I can still give you some suggestions. 1. Get IPC-7912. Use it to evaluate your CM's. Especially if you have multiple contractors supplying like products. You will quickly see
Electronics Forum | Wed Aug 16 13:31:30 EDT 2006 | a_laser
You can stop cleaning after a job when there is no more paste in the apertures. Under wiping should be done with a quality cloth and should leave no paste on the underside of the stencil (assures good contact on the next print and reduces chances of
