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 | Mon Aug 23 03:12:57 EDT 2010 | grahamcooper22
Possible route causes of bridging on fine pitch ICs are; too much paste (stencil aperture wrong), poor print quality (paste smudges during printing), pcb pads not flat depending on the solderable coating, paste has poor cold slump properties, too muc
Electronics Forum | Fri Jul 21 13:34:54 EDT 2006 | fredericksr
hot/cold slump, print misregistration
Electronics Forum | Fri Mar 14 08:38:15 EDT 2008 | davef
Pastes from different suppliers have different hot slump characteristics
Electronics Forum | Thu Nov 11 14:13:57 EST 1999 | Dave F
Thomas: From what you're telling us, you seem to be thinking correctly: 1 Paste should not spread appreciably in preheat 2 Something has changed, because you've not had this problem, until recently Two things to consider: 1 Has any thing changed
Electronics Forum | Wed Jul 28 17:46:13 EDT 2004 | Steve Stach
Both temperature and humidity can cause solder paste to behave in a way to cause these formations. Temperature can cause slumping, slumping spreads out the paste, upon reflow perimeter paste does not join the bulk, and because of insuffient oxide
Electronics Forum | Wed Apr 08 07:16:21 EDT 2009 | arrowvale
We have just switched to Almit (www.almit.com)LFM48 W TM-HP-S lead free solder paste. In general terms it is an easy printing paste, with great slump properties, wide reflow process window and offers excellent solderability on all pcb / component pa
Electronics Forum | Wed Dec 13 14:37:06 EST 2000 | Chris
I should explain that this bake out was performed after population. The solder paste slumped terribly after this bake out. However, after the back out and after reflow, no bridging.
Electronics Forum | Thu Aug 24 13:31:41 EDT 2000 | Dr. Ning-Cheng Lee
For 20 mil pitch applications, two important properties to evaluate are (1) dispensing volume consistency, (2) slump performance. As to the dispensing equipment, positive displacement will be the better choice for better consistency. Nozzle size is v
Electronics Forum | Thu Nov 18 00:13:09 EST 1999 | Thomas
10% slump). I am finding out their test std used but I think those lab test is different from real reflow as the heat transfer rate of reflow oven is much higher. Any one care to share your views?
