Electronics Forum | Thu Feb 08 09:07:22 EST 2001 | Hussman
OK, without knowing the specifics, why does everyone blame the oven? Most solder balls occur around R's and C's in almost every shop I've been to. The best place to start looking is the screen printer - not the oven. Sure the oven is the last proc
Electronics Forum | Thu Jun 06 09:28:24 EDT 2002 | Hussman69
Sure do, it's from the paste that gets squeezed under your R's and C's. This paste is now on your mask and during reflow, wants to move off the mask. Unfortunatly, it follows the flux residue to the side of your component. An easy fix is to use th
Electronics Forum | Mon Jul 16 14:48:16 EDT 2001 | mparker
Just received "Circuits Assembly", July 2001 issue. An article regarding solder balls and aperture design, beginning on page 40. This DOE had aperture, reflow profile and no clean pastes (3 types) as attributes. It is advocated that a U-shaped a
Electronics Forum | Wed Feb 07 21:56:00 EST 2001 | davef
Every critter out there with large incisors adapted for gnawing and nibbling has a different theory of solder ball formation. [My theory: It�s punishment for using NC fluxes. Stand and deliver. My solder balls end-up in the gross filter connected
Electronics Forum | Fri Jul 20 10:35:34 EDT 2001 | slthomas
David, I've thought about doing this also with no clean boards that were poorly cleaned following a misprint (and subsequently reprinted, populated, and reflowed) but have shyed away because of the potential for damage to components from the ultraso
Electronics Forum | Thu Jul 12 10:32:59 EDT 2001 | Hussman
Wow, what a string of answers and nobody brought up the easiest way to eliminate solder balls. Yes, the paste being squished under the part does reflow and work it's way out to the side during reflow. I did a 5 week study on this (when I was a bori
Electronics Forum | Tue Jun 04 17:21:22 EDT 2002 | jasonfang
I found solderballs are around chip components (on one side of middle area), I checked gerber data, solder paste of aperture on the stencil for these chip components have 5% reduction to solder land on PCB, shape of solder land are square, not home p
Electronics Forum | Tue May 11 15:52:03 EDT 2004 | Erhan
It's been 10 years since I started to use this editing method but never knew that it was called wendy-house style. :-) This is most probably the answer you're looking for if you're only having problems around the 1206 types. For QFPs, I used to redu
Electronics Forum | Wed Apr 06 21:37:35 EDT 2005 | KEN
Are you saying you have solder balls (as in solder paste balls) at the lead tips (or land tip)? This means your thermal profile is not hot enough. why the sudden cahnge? I will bet the lead frame material was copper and is now alloy 42. sounds like
Electronics Forum | Wed Nov 01 13:44:50 EST 2000 | Thomas Ballhausen
Using convection type reflow we observed following problem: One ball of a 313-PBGA appears to be dewetting. This happens randomly, i.e. no specific ball location, failure rate is rather low (3-4%), but since there are 12 PBGAs on one board the failu
