Electronics Forum | Mon Nov 06 10:29:28 EST 2000 | Dean Stadem
All of the replies have merit. Here is another one. Because the cause of the tombstoning is wetting forces that are imbalanced, and one end wets faster or more readily than the other, the 0402 lifts up on that end easily because of its low mass. Incr
Electronics Forum | Tue Oct 31 03:50:20 EST 2000 | JohnW
Honda, Prnting Glueisn't as difficult as it sounds, as long as you have the right stuff and a good set up. It also depend's on what your going to be placing. If your just doing 0603, 0805 and 1208 than you really only need an 8 thou or 10 thou stenc
Electronics Forum | Mon Oct 30 13:26:09 EST 2000 | stefano bolleri
Ramon, I have placed BGAs before with an IP-2. It can be done, but with limitations: IP-2 can only see shape of BGAs, not balls (back-light only). Is this OK for you? I only placed components with balls having 50mil pitch, and the centering with bod
Electronics Forum | Mon Oct 30 16:00:30 EST 2000 | Finepitch Services
Sal, I kind of assume you have paste there to start with... Because sometimes the edge components do not have paste applied caused by the bottom support in the screen printer etc. And if that is the case for one direction, the other direction applie
Electronics Forum | Thu Oct 26 08:59:56 EDT 2000 | Antonio A. Medina
Ok guys, I need help. Here's the deal. We're getting micro solder balls under discreets on the bottomside of the board. Here's my set up... MPM screener w/vacuum plate 6 mil metal screen with 90% circular (rounded) apertures 7 mil (measured) past
Electronics Forum | Tue Oct 31 14:52:25 EST 2000 | Dr. Kantesh Doss
Hi Antonio: You clearly have printed excessive amount of solder paste on the pad. You can reduce the amount of paste by one or two methods: 1. Switchover to 5 mil thick stencils. 2. Change the design of your stencil openings (at the discrete compone
Electronics Forum | Wed Oct 25 12:24:02 EDT 2000 | Philip
Hi Chris! I hope this will help you! The CBGA uses an array of high melting point solder spheres(Sn10/Pb90) to connect its ceramic chip carrier to an epoxy glass (FR4) PCB using eutectic (Sn63/Pb37) solder joints at both ceramic and card inter
Electronics Forum | Wed Oct 25 10:11:09 EDT 2000 | Wolfgang Busko
Paddesign, aperture size and stencil thickness determine the amount of solder for your joint. Once you have found suitable parameters you need to control the volume of your paste deposit which is influenced by printer settings, paste condition, stenc
Electronics Forum | Tue Oct 24 12:20:35 EDT 2000 | JohnW
Adam, Did some work on this a bit back via some good old Taguchi DOE and like Dave(the guru)F say's your component terminations is a big factor but I also foundthat the amount of flux you put on as well as the preheat's has an effect, generally we f
Electronics Forum | Wed Oct 18 10:02:04 EDT 2000 | Jason Nipper
I know it's a tin residue because we have a Cheme in house who had a spectrum analysis performed in an outside lab. The waves parameters were out of control long enough to effect a number of units that are, we�ll can I say substaincial in a fiscal s
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