Electronics Forum | Wed Jun 01 15:50:59 EDT 2011 | markhoch
I don't believe that particle size of the solderpaste will offer you any relief from this issue. The solder flows into the via, leeching away from the desired solderpoint, after the solder has become liquious. The chemical make-up of the solder contr
Electronics Forum | Wed Jun 01 00:25:28 EDT 2011 | alcatel
I have one pcb which has via holes on both solder pads of 0402 chips. Right now im using type 3 solder paste with 45 degree squeegee. and a lot of these chips are tombstoning. Im guessing with larger particle size of solder paste, the solder will
Electronics Forum | Wed Jun 01 14:50:09 EDT 2011 | kahrpr
Try shifting the placement location slightly toward the pad that is not soldered. This is assuming it is always standing up on the same pad
Electronics Forum | Thu Jun 02 06:23:08 EDT 2011 | alcatel
1 chip has 2 solder pads....and both pads definitely has solder.... im not getting what you are trying to say.
Electronics Forum | Thu Jun 02 06:23:40 EDT 2011 | alcatel
1 chip has 2 solder pads....and both pads definitely has solder.... im not getting what you are trying to say.
Electronics Forum | Thu Jun 02 07:27:11 EDT 2011 | scottp
You need to post a picture or describe your geometry better. Is this a through hole via in pad or is the via offset from the pad with no soldermask in between?
Electronics Forum | Thu Jun 02 10:54:12 EDT 2011 | davef
Al: We agree with AVFOM. You have a different problem than solder paste mesh selection. Most often, tombstoning occurs when the wetting forces on the two pads are unequal. Examples of things that can cause this are: * Pads are different * Board pad
Electronics Forum | Mon Jun 25 17:17:06 EDT 2007 | razor1
A German college has reported finding swarf particles on minimelf. No one state side is familiar with the term swarf. We have heard of it concerning machining and surfacing but not in the electronics industry. Has anyone heard of swarf particles on
Electronics Forum | Sat May 06 16:43:45 EDT 2006 | grantp
Hi, We have had some failures due to particles, but only larger visible particles such and you should not need a real "clean room" but it's important to make sure things are kept clean, and sweep and mop as often as you need to make sure everything
Electronics Forum | Thu May 04 11:07:23 EDT 2006 | JW
Hello, During a recent customer audit, one of their auditors asked if we measured airborne particles in our SMT operation area. Within their operations, they mentioned a concern when placing micro-BGA's. My question is: do some SMT lines use a pseudo
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