Electronics Forum | Thu May 08 21:19:46 EDT 2008 | davef
Don't allow x-outs. There has been previous discussions here in SMTnet that maybe found by searching the Archives. Steve Gregory calculated that printing paste on X-outs cost him about $50k a year.
Electronics Forum | Mon Aug 18 15:18:08 EDT 2008 | realchunks
Open the same size as the via's anular ring. Any slight off print will wet its way back into the via hole.
Electronics Forum | Wed May 19 16:35:18 EDT 2010 | stepheniii
How thick is the stencil? Also what type of paste? We have a nice little microscope that has gradients on the lens so we can measure whether an aperture is 8 thou or not. Almost always it is but then we buy from a couple of good stencil suppliers.
Electronics Forum | Mon Aug 02 14:10:50 EDT 2010 | davef
What kind of paste printing defects do you get from having the stencil tension: * Too high? * Too low?
Electronics Forum | Tue Nov 30 07:53:16 EST 2010 | edmaya33
could be a printer or stencil issue. try to check your printing repeatability. Suggest to use SPI for a checking paste volume/height/area.A regular stencil cleaning may reduced your headache.
Electronics Forum | Tue Jun 05 11:10:57 EDT 2012 | capse
hi, SMTNet has a good source for your info at; http://www.smtnet.com/company/index.cfm?fuseaction=view_company&company_id=53734 I've worked with Chrys Shea (Shea Engineering Services) in the past. She is extremely knowledgeable on printing.
Electronics Forum | Mon Aug 06 13:17:31 EDT 2012 | leemeyer
Contact Sipad Systems and see if your board is a match for their process. They use a flux that stays tacky for weeks. We have used them in the past for exactly this reason and everything worked out well.
Electronics Forum | Mon Nov 26 11:33:25 EST 2012 | pbarton
We print paste directly on to the parts then invert, place & reflow using a dedicated I/R rework station. Works well for us on a wide variety of footprints.
Electronics Forum | Tue Feb 19 03:02:01 EST 2013 | pbarton
No Pete, > > problems start with very first > print. OK, So what is the flux type in your paste?
Electronics Forum | Fri Jan 31 12:03:24 EST 2014 | markhoch
I can vouch for Keith. I've worked with him in the past on the exact two machines that Bill referenced. Keith is a fine old chap, who was very knowledgable and helpful!
