Electronics Forum | Tue Jan 11 07:46:23 EST 2000 | Dave F
Wolfgang: Boy it's tough to convey context in this medium, isn't it? Clipped from our paste storage work instruction, environmental effects on paste are: 1a Avoid excessive heat (over 80� F). It causes flux separation, reducing print quality. 1b
Electronics Forum | Sun May 23 15:12:59 EDT 1999 | JohnW
| We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendor
Electronics Forum | Mon May 24 13:33:46 EDT 1999 | Dave F
| We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendor
Electronics Forum | Mon Feb 10 16:59:57 EST 2014 | hegemon
It is sort of a self answering question if you come in from the solder paste angle. First....start gathering data. Check every day, or every new paste jar, for: Storage conditions (temp), paste expiration date, ambient temp and humidity where yo
Electronics Forum | Thu May 26 08:52:42 EDT 2011 | davef
Phil Zarrow wrote a useful paper that could help in evaluating paste. Here read it ... Evaluating Solder Paste � Not An Option Contributed by Phil Zarrow of ITM an Independent SMT consulting firm With soldering being the dominant source of assembly
Electronics Forum | Mon May 07 16:07:05 EDT 2012 | davef
Start with targets based on the stencil thickness (for height) and stencil thickness times the aperture size (for volume). * Set reasonable upper and lower control limits (+ 25% and –25 % of the targets, for example). * Next, check the printer set-u
Electronics Forum | Wed Oct 26 23:29:57 EDT 2005 | milroyperera
Hi, As I have seen in the data sheets from solder paste suppliers they always recommend to keep the solder paste until it reaches the ambient temperature after taking out from normal storage temperature. Mostly the storage temperature is 5 - 10 Cels
Electronics Forum | Tue Jul 27 22:30:19 EDT 2004 | KEN
Sr. Tech, when you say you have never had a problem, what exactly does that mean? How do you know you have never had a problem directly associated with your solder process? Do you actively measure your defect levels? How do you maintain traceabili
Electronics Forum | Wed Oct 25 12:38:05 EDT 2000 | Phil
Hi there!! You know what your QA is doing is right, coz by measuring the solder paste height can avoid the following defects: 1.Insufficient solder 2.Short solder or bridging 3.Solder balls SPC monitoring for paste height checking is required
Electronics Forum | Thu Mar 20 20:57:44 EDT 2008 | rrpowers
Well, we are in fact doing a no-clean, multi-shift, very high volume, minimal changeover operation. We use up any paste long before it gets old. Because of the sheer volume any reduction in paste scrap for us is big money. We also are in a zero de
