Electronics Forum | Tue Oct 03 11:35:51 EDT 2000 | aaronho
Screen printing has much lower profile than dispensing. So it is suitable for chips without body stand-off, (Even sot23 has stand-off). But is is much faster. Dispensers can not catch up with some chip shooters.
Electronics Forum | Thu Aug 17 08:32:49 EDT 2000 | Jacqueline
Thanks for your comment; if it is an unbalance heat distribution, why is it reflowing some cards with the BGA?? If it was a incorrect thermal profile, wouldnt they all be displaying the same problem? All boards & comps are being baked prior to rewor
Electronics Forum | Wed Aug 09 22:00:44 EDT 2000 | Dave F
Hey Charles!!! Where in earthly heaven did you get a TO263 with "large solderable tab (approx 8mm square) on the back and 5 leads"? All the TO263s that�ve reached-up and smacked me have been "TO220s" with a modified tab and three leads that are f
Electronics Forum | Thu Jul 27 21:34:41 EDT 2000 | Dave F
Gary: That's curious. Tell us more about your process steps, temperature profiles, paste, warping of the board without the PIH processing, components, etc
Electronics Forum | Wed Jun 14 08:08:56 EDT 2000 | Wolfgang Busko
Hi ji tae, we had a similar problem with QFPs 0,5 pitch processed by one subcontractor. The symptoms we noticed were: - the solderjointshape and wetting looked normal - the surface had a dull gray appearance - by pushing a lead sideways with a tweez
Electronics Forum | Tue Apr 03 22:07:20 EDT 2001 | spchua
Hi, as what's I understand, there have no any standart of these. In order to prevent these or to improve these, please check the rework temp. profile.
Electronics Forum | Wed May 10 01:17:47 EDT 2000 | Edmund S. Molina
How to avoid tombstoning of film capacitors. The temperature profile is within standard/specifications, printing is good and placement is okay but tombstoning of film capacitor still occur. I need your help. Thank you.
Electronics Forum | Wed Apr 12 09:20:57 EDT 2000 | C.Long
anyone any ideas how to minimise my DPM as regards tombstoning..i have checked oven profile..appeture size on my stencils..placement machine etc and still problems.???????????
Electronics Forum | Sat Apr 08 09:32:51 EDT 2000 | Matt
Make sure your screen aperture size is about 80%, and you should not have a problem. Some pastes require a hump profile, to get rid of balls.
Electronics Forum | Thu Mar 02 11:56:04 EST 2000 | Dave Pearcy
We are experiencing the same problem. We just spent $1,200 to figure out that the "black stuff" is a Nickel Oxide. I am going to look into the profile end of this problem. Any suggestions would be very helpful. Dave
