Electronics Forum | Thu Jun 14 20:03:42 EDT 2007 | davef
If you're concerned, consider reducing the period used to monitor pot temperature in your process monitoring. Then, if you observe temperatures that ramp out of control more often than you expect, it might confirm the suspicion about damage to your
Electronics Forum | Mon Jun 18 10:34:40 EDT 2007 | swag
If you are using a fixture/carrier in the oven, make sure that it is not too restrictive on the perimeter of the board/panel. A carrier intended to limit warpage can actually cause warpage if the expanding PCB material has no place to go during refl
Electronics Forum | Mon Jun 18 14:46:24 EDT 2007 | ck_the_flip
I have heard that with lead free soldering, the cooldown phase is NOT as critical as it is for Tin-Lead. -2�C per second cooldown is good enough to form a good solder joint with good grain structure.
Electronics Forum | Sun Jun 17 02:19:47 EDT 2007 | Frank
You can grab a measuring tape and get the size yourself. Those machines are pretty small, I can't see them weighing more that a few hundred pounds. Contact Juki (the real makers of those machines) and I am sure they could dig up the actual weight.
Electronics Forum | Mon Jun 18 02:15:20 EDT 2007 | pavel_murtishev
Good morning, 5mil stencil or less would be appropriate. We deal with 0402's daily and 5mil works. BR, Pavel
Electronics Forum | Mon Jun 18 10:02:26 EDT 2007 | dyoungquist
5mil should work fine. Some stencil manufacturers charge more if you go less than 5mil so stick with 5mil.
Electronics Forum | Thu Jun 21 07:21:26 EDT 2007 | chrispy1963
5 mil is perfect for 0402's. If you are printing SnPb solder use apeture reduction such as home plating the pads. However, if youre using SAC, we've found that printing the entire pad works best due to poor wetting compared to SnPb paste. Chris
Electronics Forum | Fri Jun 22 10:56:07 EDT 2007 | ed_faranda
5mil works great. Just make sure that you screen alignment is dead on. We're using a SAC305 with a home plate design. I ran a test a couple of months back and found that the home plate design works the best with 0402s.
Electronics Forum | Wed Jun 27 21:16:20 EDT 2007 | rfrog
5 mil will treat you just fine. Do some research on stencil area ratio and aspect ratio if you ever reduce your aperture sizes any further.
Electronics Forum | Sun Jun 17 20:03:57 EDT 2007 | davef
We agree. Further, Captcha is not very effective in limiting the ability of computers to replicate the entry code. But the good news is that the verification software that is effective in preventing computer scanning is doubally difficult for human
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