Electronics Forum | Mon Jul 01 16:15:02 EDT 2002 | Matt Kehoe
We are currently trying to gather information pertaining to applying LPI soldermask thicker than normal. The thick coating is necessary for the SIPAD ssd process however, because of the numerous brands of mask and application methods there is no sing
Electronics Forum | Wed Feb 04 16:33:40 EST 2009 | davef
Your specification for all PCB suppliers of 'solder mask over bare copper using LPI on external layers (green)' is broad and open to the use of material from many possible LPI suppliers by your board fabricator. In at least one case, it appears that
Electronics Forum | Thu Oct 14 18:23:40 EDT 2021 | mikeybinec
OK, thanks for access a few decades ago when I was a kid, I printed soldermask and legend inks on circuit boards. Printing solder mask, (PC-401, SR1000, LPI) I would use SM-1000 stencil material on 86 or 110 mesh I've been trying to find sm-1000 bu
Electronics Forum | Mon Jul 01 20:45:38 EDT 2002 | davef
Solder mask thickness specifications by fabricators are: * Wet mask: 0.0002 ~ 0.0004� on trace * LPI mask: 0.0002 ~ 0.0008� on trace Liquids usually range between 10 to 13 um (0.00039 to 0.00051") when dried. Liquid resist processes I have seen are
Electronics Forum | Fri Jun 09 17:34:08 EDT 2000 | Melanie Mulcahy
I need some information regarding the acceptability/unacceptability of using tented vias with LPI soldermask. Long story on all involved, but basically I have a board that I have had manufactured with no problems which has BGA/uBGA parts, tented via
Electronics Forum | Sun Aug 23 11:42:01 EDT 2009 | ysutariya
Hi Dave, I haven't tried the Probimer yet, but the Taiyo ink didn't hold up too well. As a PCB fabricator, finding a white soldermask that has good trace coverage and survives 4X solder immersion (HASL) is like the holy grail of white soldermask.
Electronics Forum | Mon Apr 22 15:05:47 EDT 2002 | tim_easterling
Depending on the volume of boards you are manufacturing, the most cost effective solution would be to epoxy plug the vias prior to LPI soldermask application. The technique is common practice and most suppliers can provide it will little or no cost a
Electronics Forum | Thu Sep 10 11:47:44 EDT 2009 | mikesewell
The adhesive should be a dielectric (insulator) by design, if not it could possibly short across leads of the very parts it's intended to secure. It normally isn't a concern - what is the surface resistance of your soldermask, bodies of ICs, ...etc.
Electronics Forum | Fri May 07 16:28:07 EDT 1999 | Andrew Wulff
On 1.27mm (0.050 inches) Standard Ball Grid Array's. The ball size diameter starts at approximately 0.025 inches. If the ball size decreases to 0.012 inches (due to the solder flowing down a via) is the solder connection reliable? This is a known L
Electronics Forum | Tue Aug 18 10:18:22 EDT 1998 | Dave Hulbert
I have a question on tenting of vias on PWB's. I have designed a 6 >layer, military, mixed components (all on top side), LPI soldermask >board which will be run over the wave. I was planning on tenting vias >but did not specifically specify that on f
