Electronics Forum | Thu Dec 08 15:27:54 EST 2005 | Samir Nagaheenanajar
Yes, yes, I agree with American man, URL, on all his points about having to know the overall process 1st. I'm surprised he doesn't have his own free consulting website. Other things you can try are: * "Dog-bone" apertures... taper down the apertur
Electronics Forum | Thu May 24 08:55:25 EDT 2007 | ck_the_flip
Here's some quick things to look for: 1. Does your solder paste feel like concrete, does it roll-up into your squeegee blades, and stick to your stencil? If so, your problem is the solder paste. The mixture of powder and flux, or metal load is ou
Electronics Forum | Fri Feb 22 14:22:07 EST 2008 | stevek
Are you using nocleans, especially when you get to SMT? Years ago, I had OA wave flux get into vias that were plugged from the top under parts. It is really difficult to clean small, high aspect ratio vias. Cross sections showed that the copper in
Electronics Forum | Wed Jul 23 08:18:29 EDT 2008 | davef
Q1. Is this a standard process for plugging? A1. Not as such. We checked both IPC-6012 and IPC-SM-840. Neither comments on plugging. So, your fabrication notes rule the day. Q2. Is this okay for such thick PCB's or is it mandatory to use a special pl
Electronics Forum | Tue Dec 23 17:34:07 EST 2008 | davef
We hear you talking two main issues: 1 Solder paste release 2 Thoughts on using two passes of solder paste on the stencil 1 Solder paste release * Check your aperture & aspect ratios [Search the fine SMTnet Archives for more] * Do a better job with
Electronics Forum | Wed May 30 21:16:05 EDT 2001 | davef
MPM AP-27 preferred over MPM AP-20 The issue is release of paste from the stencil. A vertical lift printer kinda snaps the stencil away from the board to complete the print cycle. The inertia and the rheometric properties of the paste make it rele
Electronics Forum | Wed Jun 20 12:07:13 EDT 2001 | Steve
I would suggest getting a copy of IPC-SM-782A, Surface Mount Design and Land Pattern Standard, and IPC-7525 Stencil Design Guidelines. My experience is that reflow does not cause tombstoning very often. Pad and land design, paste volume, and placemen
Electronics Forum | Fri Aug 13 18:38:47 EDT 2004 | russ
Your paste manufacturer will have the best guidelines for you. Different paste types and manufacturers sometimes/usually require a little bit different setup. I would also contact your printer manufacturer. As far as stencil concerns the larger/be
Electronics Forum | Mon Aug 30 11:20:12 EDT 1999 | John Thorup
| | | Planning to evaluate the above process... | | | Can anyone can give me some tips/infos on the above.... | | | e.g. stencil aperture design, aperture ratio, common problems and solutions they encountered on the above process, is the profile diff
Electronics Forum | Mon Aug 30 12:02:16 EDT 1999 | Brian Wycoff
| | | | Planning to evaluate the above process... | | | | Can anyone can give me some tips/infos on the above.... | | | | e.g. stencil aperture design, aperture ratio, common problems and solutions they encountered on the above process, is the profil
