Electronics Forum | Tue Feb 17 01:12:52 EST 1998 | J.H. Kim
In solder bumping in flipchip technology by splder printing, the precise control of solder volume and height is very difficult. Therefore I'd like to know the solution of this problem. Thanks
Electronics Forum | Fri Apr 27 11:24:53 EDT 2007 | realchunks
Hi Steve-O, Good question(s). This process was set-up by an engineer that had a PhD in statistics, took him a year to develop and then thru it over the wall at us. The biggest problem we saw was SPC to measure solder volume. SPC is good for measu
Electronics Forum | Wed Jan 30 17:23:07 EST 2013 | dyoungquist
In response to hegemon... This is not a recommended practice but..... We have added a few drops of water soluble flux to our water soluble solder paste when the paste is on the stencil. This was after the paste had "dried" out a bit. We have had
Electronics Forum | Wed Jan 30 19:59:22 EST 2013 | hegemon
To dyoungquist - I understand that situation. I can see where that is possible in the case that your paste has gone a bit dry. As you said, not neccessarily the recommended practice, and yes your print regularity can go out the door. However, I th
Electronics Forum | Thu Apr 29 17:35:17 EDT 2004 | Shinmoto
Hi there, We place FBGA packages on a lot of our memory modules. Our stencils have .013" square apertures and a .005" foil thickness. We are using a type 4 paste from Senju Comtek. The price difference is not that significant and readily available
Electronics Forum | Thu Apr 26 11:40:10 EDT 2007 | CL
Good Morning, We have a 3D solder paste inspection machine. We purchased it on a recommendation from a consultant. We are a CM high mix low volume. The President of my company has attended some seminars and meetings where it was conveyed to her that
Electronics Forum | Thu Jan 03 08:02:53 EST 2002 | davef
Slump is a function of the particular paste you select and the temperature of the paste. Use a slump test like the one that follows to compare fluxes. Slump Test Step Process activity 1 Print paste on white ceramic substrate or microscope sli
Electronics Forum | Fri May 21 15:50:41 EDT 1999 | John Thorup
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 vendors
Electronics Forum | Thu Mar 22 14:12:09 EST 2001 | slthomas
Interesting...the very reason we use water soluble paste on some of our boards is for that reason, although I've never been able to get anyone to show me something in print that supports it. It's just what engineering has told me. We currently have
Electronics Forum | Fri Apr 04 08:49:45 EDT 2008 | ck_the_flip
Define "expired" though... 1 week? 6 weeks? 1 month? 6 months? Unrefrigerated life is generally 30 days. If paste has been stored refrigerated at manufacturer recommended temperatures, what would you guys do, like say, if you owned your own shop
