Electronics Forum | Thu Dec 08 22:41:44 EST 2005 | davef
Mike: You're correct, but in better shops there are guys with little black books in their back pocket. They know how to contol their variables and give you a good product. I worked at this plant where we cooked dirt. It glowed orange-red and flow
Electronics Forum | Fri Dec 09 08:53:12 EST 2005 | russ
We used flash gold once by mistake and we did pay for it. A very high fallout of BGAs and some of the leaded devices for latent failures from fractured solder joints. I do not know how the other types of components faired in this process but I woul
Electronics Forum | Tue Dec 13 22:44:35 EST 2005 | Mike Kennedy
Russ, After a bit more research, I have found that the FLASH gold process doesnt use Phophrous in the process so should not have the black pad problems of ENIG. I am now surprised that you had problems. What did you experience? Was it an oxsidisation
Electronics Forum | Wed Dec 14 08:58:27 EST 2005 | russ
We experienced brittle solder joints that did not withstand thermal cycling as I was told. I am positive about the fractured joints but was informed by customer that it was thermal cycling of the part when they failed so they were latent failures.
Electronics Forum | Thu Dec 08 12:24:11 EST 2005 | cyber_wolf
Any good stencil house should be able to recommend the proper configuration on a fine pitch aperture design. They can also advise you as to which foil thickness works best. The norm foil thickness is .005" - .006". There are always special instances
Electronics Forum | Fri Dec 09 08:11:56 EST 2005 | rlackey
I'll rephrase that - you've got rather a lot forward! Thanks on the zipper - wasn't sure if there was another trick to learn there. We used to use it on crap free issue boards with no solder mask between the pads, and on ultra fine pitch before we
Electronics Forum | Mon Dec 12 16:08:37 EST 2005 | pjc
Here are some guidlines: http://www.tkb-4u.com/articles/printing/stencildesignguide/stencildesignguide.php www.indium.com/documents/applicationnotes/97742.pdf http://www.electronics.ca/standards/general/IPC-7525.html http://www.alphametals.com/pr
Electronics Forum | Wed Dec 14 06:10:24 EST 2005 | tk380514
some of th IPC design guidelines have helped my factory understand the importance of stencil, (before me they used 9 year old guidelines) carzy i know, if you are interested in stencil design then listen to what everyone else has been saying however,
Electronics Forum | Wed Dec 14 07:46:41 EST 2005 | chunks
Yup, I saw the original question too. I just can't see how any one would let a stencil manufacturer dictate their processes. Maybe if your designs are small and straight forward, but are you really going to let a stencil maker tell you what product
Electronics Forum | Thu Dec 08 13:17:31 EST 2005 | Amol Kane
during my researches for LF transition, a question being asked is -- why even consider immersion tin if it whiskers. does it really matter?, because during reflow, the Sn dissolves in the SAC solder alloy and does not exist in a "Sn whisker" formabl
