Electronics Forum | Wed Dec 11 20:40:25 EST 2002 | davef
Se�or Tech Consider the following in evaluating your adhesive: * Determine the ability to dispense/print epoxy dots over the full range of application diameters/volumes. * Assess the ability to dispense/print epoxy without undesirable characteristic
Electronics Forum | Thu Dec 05 17:40:24 EST 2002 | davef
While unfamiliar with some of the terms you use, could this be what you seek? http://www.pcbstandards.com/downloads/Metric%20Environment/General%20Documentation/PCB%20Design/PCB%20Design%20Routing/Metric%20BGA%20Routing.pdf Stepping backwards just
Electronics Forum | Mon Dec 09 21:15:27 EST 2002 | MA/NY DDave
Hi I haven't looked yet at what DaveF gave you. It is my guess that your SJR stands for Solder Joint Reliability. The answer would in general be NO to your question. Usually things in the design community are done in steps that provide a certain
Electronics Forum | Thu Dec 05 17:10:17 EST 2002 | EW
It is an interesting topic. This will tell you if they are cleaning the boards well(Di). We typically warn our fab houses if we see them head up or over 4 micrograms per square inch. On occasion we have seen upwards of 20, and "rejected" I think
Electronics Forum | Fri Dec 06 10:16:57 EST 2002 | davef
Bare board cleanliness is still primarily measured by resistivity of solvent extract (ROSE) using instruments such as Omegameters and Zero Ions. What is considered as "acceptable" cleanliness varies between specification and from company to company.
Electronics Forum | Mon Dec 09 08:30:13 EST 2002 | MA/NY DDave
Hi Well you already got good answers with some diversity, yet from what I read they are giving you the answers for Assembled PWBs, i.e. post solder or PWAs. I don't remember ever doing this for raw boards. For most of the current pwb finishes it se
Electronics Forum | Mon Dec 09 20:50:08 EST 2002 | MA/NY DDave
Hi I kind of agree without any reliability studies. Where are the Ionics coming from? After Soldering depending on chemistry I think we agree? Yet these are bare boards after many processes and even testing that should scrub out or off the Ionics.
Electronics Forum | Tue Dec 10 18:30:15 EST 2002 | MikeF
From personal experience, if the PWB vendor is cutting costs and doing their final rinse with tap water instead of DI you will get ionic contaminants left on the board. You might consider having CSL, or one of the other independent labs mentioned e
Electronics Forum | Thu Dec 12 13:53:01 EST 2002 | gregoryyork
Considering only Ionic residues is very dangerous, most heat transfer fluids that are extremely hygroscopic are also non ionic especially those used in HASL / Roller Tinning fluids. Also consider if the resist is cured or in fact porous which absorbs
Electronics Forum | Tue May 18 22:31:05 EDT 2004 | davef
Ionic cleanliness is pretty much meaningless, when discussing nc flux residues. If you do the good solder routine and measure the boards, you'll be in the out-house, because the water in your resistivity of solvent extract tester will turn the res o
