Electronics Forum | Fri Sep 10 17:18:10 EDT 2010 | spitkis2
They may be misaligned so much so that self centering would not occur. How are you placing the micro BGA's? Depending on how the boards are transported onto the oven's conveyer, by the time they start to go through the oven, there could be additio
Electronics Forum | Mon Jan 09 17:52:50 EST 2023 | duchoang
The reasons could be: -The pads size are uneven. Modify the pads size. -The part has not enough time for self-centering. Check and increase TAL. -Solderpaste not melted completely. Increase peak temp. -Solderpaste does not work well. Use alternate so
Electronics Forum | Tue May 22 17:21:43 EDT 2001 | davef
BGA require placement accuracy of only 0.3mm (�12 thou), compared with a required placement accuracy of 0.08mm (�3 thou) for fine pitch devices. Even with this level of misalignment, plastic BGA self-center / self-correct during reflow due to symmetr
Electronics Forum | Fri May 26 05:49:09 EDT 2000 | Richard Wilders
1.67. A lower accuracy will result in many off-pad flipchips; this means a lot of displacements. And there is no chance at all the flipchip will self-center back to the correct placement spot. I think you'll have to evaluate machinery that is capabl
Electronics Forum | Wed Apr 28 10:13:24 EDT 2004 | onesime
Hi out there, I have an ongoing project in wich I have to use several BGAs. As I have no practice at soldering those components I want to take advantage of their self centering features . can any one gives me a tip on securing components? does any on
Electronics Forum | Mon Oct 31 08:29:51 EST 2005 | chunks
Shifting? Please describe the "Shifting". I.E. is it centering, sliding to cause shorts..... Most 208s will self center. If it's causing shorts, first check your print to make sure it is on the pads. Next check placement. Another area to check
Electronics Forum | Mon May 28 07:50:08 EDT 2007 | pavel_murtishev
Good afternoon, Have you checked placement accuracy? Is it installed without shift prior to reflow? Are you sure it shifts in the oven? I believe tension cannot cause QFP shift since QFP has quite low self centering ability. Such kinds of shifts are
Electronics Forum | Mon Mar 10 09:19:15 EDT 2008 | lysik
As you know 90% of defects come from the printer. This product is well worth the investment. You will improve yeilds and reduce rework. Very important with micro BGA's. Also lead free components do not self center (during reflow) as well. There is ve
Electronics Forum | Thu Feb 05 02:34:05 EST 2009 | sachu_70
Hi Manuel, most passives are chip components. These tend to self-center/align during the reflow process. However, you need to ensure that there is a uniform balanced solder paste deposit. I had tried few such ovals in earlier stencil designs and resu
Electronics Forum | Mon Jan 13 14:44:19 EST 2020 | dwl
I wouldn't think the vibration from weights dropping would be significant enough to effect the SMT machines. If you are concerned, look into placing vibration dampening pads under the machine feet. you don't need anything fancy, just neoprene pads wo
