Electronics Forum | Tue Mar 30 17:52:15 EDT 2010 | cusackmusic
They are very finiky. If you have good solder paste, and a slight down pressure, to make sure the LED is "stuck" to the board, you should be able to place it. Pick it up on the center of the flat, NOT the lens. Even with the vacuum turned off, t
Electronics Forum | Wed Sep 01 08:25:31 EDT 2010 | sachu_70
Tombstoning is a result of imbalanced force experiences by the device during reflow due to unequal behavious of the solder paste across all sides of the device. Could be due to many factors a few of this are: (1) Unequal solder mass distribution, (2)
Electronics Forum | Tue Nov 02 07:50:18 EDT 2010 | babe7362000
I just need a clarification on NC254 No clean solder paste. If we have parts on the bottom side of the board that already are soldered and we go to run the other side of the board and it was misprinted, is it ok to run thru the washer? I just need
Electronics Forum | Wed Jan 12 17:24:16 EST 2011 | piter
HI Ok solder past seems to be ok, but what type do you have finihing of PCB(ENIG, immersion silver, SN100??), second what type of solder alloy do you have on BGA, its important, I don't think that you have problem with stencil. answer on my questio
Electronics Forum | Wed Jul 06 13:56:35 EDT 2011 | cyber_wolf
The only thing I have ever heard of that prints solder paste (accurately) without a stencil is a Mydata MY500. You can buy thousands of stencils for what this machine cost. You should not have long lead times on stencils. We get ours next day for no
Electronics Forum | Wed Jun 20 08:46:15 EDT 2012 | jdengler
Hello all, We have a customer requesting the use of Sn95/Sb5. Of course they are in a hurry and I have not found any in stock. I need solder paste and cored wire. We can use water soluble or low residue (no-clean) flux. Anyone have a lead on a s
Electronics Forum | Sat Aug 25 23:01:45 EDT 2012 | ssridhar
Hello jdumont, I think the spheres are leaning as there is not enough meat under the spheres. In ceramic BGA devices there is a solder fillet which is generally a solder paste which is used to give the device some height before balling it. This heig
Electronics Forum | Mon Oct 15 08:24:24 EDT 2012 | scottp
You could pay the extra to have the microvias plated shut and planarized. If your voids are larger than 25% of the BGA joint area then I would suspect a solderability problem. Either the board plating or a solder paste problem. If they're less tha
Electronics Forum | Fri Feb 08 16:21:15 EST 2013 | spitkis2
Are you doing this to minimize solder paste splattering? Is this a value that you use for all QFN's (would the overall size of a QFN matter)? I was told reducing placement force with these components is recommended so just was wondering what is bein
Electronics Forum | Wed Jan 04 07:32:35 EST 2017 | pavel_murtishev
Good day, Having recieved new batch of PCBs with OSP surface finish, I have noticed that some polygons not covered by solder mask and solder paste become darker after second reflow cycle compared to PCBs not being sent to reflow. I wonder whether i
