Electronics Forum | Tue Sep 18 11:34:36 EDT 2001 | jschake
The tightest spacing between neighboring 0201 components assembled was 8-mils. Please refer to the response for the query entitled �Minimizing Tombstoning Defects� posted by martys, as the response provided there is also relevant to address this que
Electronics Forum | Mon Oct 15 10:51:49 EDT 2001 | davef
On over printing, the general issues are: * Paste deposits being so large that when reflowing, collapse onto many, rather than a single solder mass. * Paste expanding during heating and being close to other solder deposits and bridging [as you say].
Electronics Forum | Mon Sep 23 18:11:10 EDT 2002 | steveb
On an assembly reflowed in air saw the same thing: 0201's with a grainular solder joint, but 0402's and above with perfectly formed joints. Reflow profile all within acceptable tolerances. Reflowing in nitrogen solves this problem, but increases t
Electronics Forum | Wed Apr 11 19:32:39 EDT 2001 | Adam
I'm trying to find information/articles describing the effects of temp and humidity on solder paste. Just recently we have gone through a change outside temperature and humdidty and have notice solderabilty problems with smt boards.
Electronics Forum | Fri Jun 23 10:10:15 EDT 2006 | Gman
Some amount of voiding was always seen on sites where solder paste is printed. These voids are much smaller. However the site where a flip chip is flux dipped has never had problems with voiding. Macro voids (and huge ones at that)across the board s
Electronics Forum | Thu Nov 30 15:19:56 EST 2006 | CK the Flip
Mike, dude, I feel your pain. Hearing stories like this makes my blood boil! It's almost as ridiculous as a customer who told me to put more solder paste on a MELF component to overcome noise issues - he used more solder paste as antennas to overco
Electronics Forum | Sun Mar 01 15:52:13 EST 1998 | Earl Moon
| From several months I am investigation about the VOIDS PERSENCE and his important as reliability. | One question now is : | It is possible that on the BGA components the voids are already present into the balls, before the mounting on the pcb ? | I
Electronics Forum | Tue Nov 11 16:30:08 EST 2008 | naynayno
Occasionally solder mask thickness is believed to be the cause of gasketing challenges during paste printing. We currently specific IPC-SM-840 on our fab drawings but this provides no limits or guidelines on thickness. I do not want to cause an unr
Electronics Forum | Tue Nov 11 17:35:08 EST 2008 | davef
SM-840, is a material qualification document only, with all the test requirements applicable only to a defined test coupon, not to production boards. So, it's useless for what you're trying to accomplish. As assemblers use A-610 - Acceptability Of E
Electronics Forum | Tue Jul 09 15:20:19 EDT 2002 | pjc
When you look at the capabilities of Combo machines they tend to sacrifice performance when compared to separate X-ray and AOI machines, meaning they don't do either the X-ray or AOI operations as well as a machine that was designed to do only one. A
