Electronics Forum | Tue Jun 04 13:13:58 EDT 2002 | slthomas
Another thing we see is solder balls (sometimes fines, sometimes larger stuff) in the vias after a misprint has been poorly cleaned, as in wiped down but not washed. They end up in the plated through holes too, but those get nicely cleaned up in the
Electronics Forum | Tue Jun 04 14:14:42 EDT 2002 | ckd
I meant to include this in the original message. One, the solder balls are on the circuit side of PCB. Two, some of the vias on both top and bottom are closed and some are not. Is this a process problem with the board house(s)?
Electronics Forum | Tue Jun 04 15:52:44 EDT 2002 | Hussman69
Closed by solder mask? At any rate, still sounds like wave solder. Take a look before and after wave. That should tell ya.
Electronics Forum | Thu Jun 06 07:33:04 EDT 2002 | cyber_wolf
Whoa ! sorry guys I thought my post from yesterday did not go through. Anyhow they both mean the same thing.
Electronics Forum | Tue Jun 04 18:21:29 EDT 2002 | arzu
We have "conductive" coats,shoes,floors,chairs and wriststraps. I want to get rid of the wriststraps, for the wires can ruin a product during touchup and hand-building SMD components on paste. My Question: when do we have enough ESD protection?? are
Electronics Forum | Wed Jun 05 18:05:04 EDT 2002 | davef
The issue is not the shoes, coats, straps, or doodangs. This issue is the voltage that the component / assembly 'sees'. * What voltages are you seeing in this work area? * What voltage will damage the components in this work area?
Electronics Forum | Tue Jun 04 22:46:21 EDT 2002 | davef
Factors to consider are: * Squeegee speed * Squeegee pressure * Separation speed * Stencil thickness * Stencil aperture fabrication method * Stencil aperture shape * Paste type * Stencil under-wipe frequency Search the fine SMTnet Archives for a thr
Electronics Forum | Wed Jun 05 14:44:49 EDT 2002 | arzu
Hello again, Indeed most of the mentioned factors we will use as variable parameters, and some of them we keep fixed. I am interested in the way how to measure results. Thanks for the hint to dig into former paste-printing threads; I will look at
Electronics Forum | Thu Jun 06 03:41:28 EDT 2002 | ianchan
Hi mates, just to add-on, for DOE, also include squeegee printing direction as a factor. Good Luck! happy DOE-ing.
Electronics Forum | Thu Jun 06 21:42:17 EDT 2002 | davef
Hussman, What is a Cyber Centry? Who makes it? What does it do? What kind of accuracy does it possess? Cost? etc.
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