Electronics Forum | Thu Jul 27 07:50:35 EDT 2006 | davef
Send us pix
Electronics Forum | Mon Jul 24 11:35:42 EDT 2006 | Jimk@ics-inc.org
We have experienced a problem with tin leaching or discoloration of lead terminals on random parts on solder side of a paste/paste operation. The profile has been used on previous production runs and there doesn't appear to be any heat damage to othe
Electronics Forum | Tue Oct 27 05:51:28 EST 1998 | jacqueline coia
Could you please tell what are the current avaliable standards, if any (BSI/IPC) for a measurement value on the mechanical pull strength on SMT IC leads after reflow. Thanks in advance, Jack.
Electronics Forum | Sat Aug 21 15:07:34 EDT 2010 | jry74
I have a problem with solder bridging between IC leads, especially fine pitch leads. If we lessen the apature ratio and/or decrease stencil thickness, I have more of a chance for unsoldered or insufficent joints. I am looking for any information th
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 | Mon Aug 23 13:59:18 EDT 2010 | swag
Under a scope, make sure the PCB has soldermask between pads.
Electronics Forum | Thu Feb 18 21:20:13 EST 1999 | Ernie Flamont
During inspection and test we find leads which do not get soldered. Some are because of insufficient paste, but with others everything looks right. This will only happen on 1 to 2 pins, and it is not isolated to a specific type of ic or location on
Electronics Forum | Mon Aug 23 17:43:18 EDT 2010 | davef
SAG: Questions on solder mask webbing with fine pitch parts are: * What is the minimum pitch that you can use webbing between fine pitch pads? * What solder mask do you use?
Electronics Forum | Wed Sep 01 08:05:28 EDT 2010 | sachu_70
Solder mask between pads in case of fine-pitched device footprint may not be a practical solution to implement. Cheers !!!
Electronics Forum | Mon Aug 23 14:09:56 EDT 2010 | davef
Similar to Coop's comments, above ... Bridging: * Mis-placement: misplaced components, high placement force mushrooms paste * Too much paste: HASL thickness, lead finish, poor underside support, poor underside wipe frequency, printing with too lar
