Electronics Forum | Tue Apr 28 08:51:35 EDT 2009 | davef
This is a snip from an ealier post here on SMTnet. Generally, solder pastes are comprised of: 90% solder powder, 5% flux, 4% solvents, and 1% activators [by weight]. Where: * Solder powder, when reflowed, is a metal bonding agent that mechanically
Electronics Forum | Thu Oct 07 17:05:38 EDT 1999 | Bix
I am thinking on testing or possibly changing my company's solder paste brand. Anyone have any suggestions or hints on how to cover all my bases before making such a bold move? Present paste used: Alpha WS-629 Paste to trial: Multicore OA Sys WS-22.
Electronics Forum | Thu Jul 09 10:10:40 EDT 1998 | MAURICE MCCLAIN
IS IT BETTER FOR SOLDER PASTE TO SPREAD OUT AS FAR AS POSSIBLE ON BARE COPPER, OR FOR IT TO KEEP THE SHAPE OF THE PRINT? I'VE BEEN DOING SOME SOLDER PASTE EVALUATIONS, AND I'M TRYING TO EVALUATE THE RESULTS. I'M NOT SURE THAT BECAUSE A PASTE MAY HA
Electronics Forum | Thu May 10 15:32:45 EDT 2012 | 14367
We are having a lot of tomb stoning with this no clean solder paste. It's limited to larger, complex boards, affecting 0603 ferrite beads, capacitors and SOT23s. It was suggested that paste removed from a stencil should not be put back in it's origin
Electronics Forum | Fri Mar 15 16:06:30 EST 2002 | shan
80??? Whatever leads to you to that assumption? I'd love to see a study stating that. Based on experimental results at our facility, overvolume due to the screener parameters have rarely caused a solder short. so, in conclusion, does one need a solde
Electronics Forum | Tue Aug 29 06:00:47 EDT 2006 | bwet
Ladies and Gents: There have been several studies including (http://www.solder.net/PDFs/LeadFree_BGATesting_InitialCycling_BEST.pdf) which have shown lower fast pass yields with solder paste. Based on internal projects of 1000+ of the same BGAs we a
Electronics Forum | Mon Dec 27 13:34:28 EST 2010 | ppcbs
Does anyone have any experience in printing solder paste on a 0.0065" pad? I have a requirement to attach single chips with 600 to 2400 connections. The chip has a 0.005" solder ball, 0.010 pitch. Attaching to a substrate with a 0.0065" pad. An
Electronics Forum | Thu Aug 02 09:56:57 EDT 2012 | mccabekev
We currently operate a procedure of keeping fresh tubes of solder paste in a fridge. When it is required we remove the required quantity from the tube and return the tube to the fridge before it warms up to room temperature. We then store this at r
Electronics Forum | Wed Mar 12 15:26:46 EDT 2014 | dan_ems
Hello, in my SMT process I have some problems with the solderability (look like dewetting) on a PCB with finish HASL Lead Free with a composition that is melt at 230 degree Celsius. My oven is with vapor phase and the peak temperature is 230 degre
Electronics Forum | Mon Aug 08 18:59:49 EDT 2016 | oleksz
What should be solder paste stencil aperture proper size in comparison with PCB copper pad for lead free technology? When designing PCB foortprints I was using solder paste pad undersize of 2.5 mils (0.06mm) per side (solder paste pad size was 2.5 m
