Electronics Forum | Fri Sep 24 10:57:18 EDT 1999 | Earl Moon
| Hi Folks: | | We've been having bridging problems on our fine-pitch QFP's, despite thorough inspection of paste height, volume, and placement accuracies....profiles look good also. | | The bridging is happening after coming out of reflow...one la
Electronics Forum | Tue Feb 28 17:22:23 EST 2006 | dave
All, I am currently trying to run a quantity of boards thru my wave machine but I am having serious issues with hole-fill or lack of aswell as others. The boards are HASL finish and due to materials issue they have been waiting for Wave Solder Proce
Electronics Forum | Fri Dec 15 13:57:46 EST 2000 | genny
It is only after the reflow heating process that the peaks may show up, as the solder build up in some vias(due to HASL'ing) might drip down during reflow. I don't think I've ever heard of it being desirable to have a bare copper surface that will ox
Electronics Forum | Mon Apr 17 19:30:27 EDT 2000 | Boca
All of the above is good stuff. To add, I have seen this several times if the assembly is wavesoldered. Heat from the wave can partially reflow the top side SM solder joints and weaken them. To test, check joint strength before wave and then after
Electronics Forum | Thu Jun 17 10:37:42 EDT 1999 | Brian Wycoff
| | | | | Our company is experiencing cracked caps at our pick and place operations. The caps are being placed onto epoxy dots for subsequent wave solder operations. At present, be have set the pressure of the head at 2 in/lbs. This being down from
Electronics Forum | Mon Jun 14 11:39:29 EDT 1999 | Marshall
| | | | Our company is experiencing cracked caps at our pick and place operations. The caps are being placed onto epoxy dots for subsequent wave solder operations. At present, be have set the pressure of the head at 2 in/lbs. This being down from m
Electronics Forum | Thu Jun 17 11:18:03 EDT 1999 | Ian Clelland
| | | | | | Our company is experiencing cracked caps at our pick and place operations. The caps are being placed onto epoxy dots for subsequent wave solder operations. At present, be have set the pressure of the head at 2 in/lbs. This being down fr
Electronics Forum | Thu Nov 19 05:25:07 EST 1998 | karlin
| | We are experiencing 'lifting' on one or more sides of a QFP. Poor lead co-planarity has been ruled out by independent tests. Please tell me which of the two remaining failure modes is the most probrable? | | | | 1. Expansion of gases in vias und
Electronics Forum | Thu Aug 10 13:16:17 EDT 2000 | Bob Willis
Here is some thing that I wrote a while back on solder beading. First what is a Solder Bead? The term solder bead is used to differentiate it from solder balls. A solder bead is a solder ball but its location is normally constant unlike solder bal
Electronics Forum | Fri Feb 29 08:12:56 EST 2008 | davef
Solder paste suppliers often make recommendations on solder paste handling after removing it from the container [eg, jar, cartridge, etc]. For instance, Multicore Solder Paste Handling Guidelines, September 2004 says: As a general rule, paste that h