Electronics Forum | Fri May 10 14:02:05 EDT 2002 | pjc
First off what bone-head designer put them there in the first place. Vias in solder lands is a big time no no. I had this problem at a CEM I worked at. I had the customer change the design but had to run the 6 samples they supplied. I ended up fillin
Electronics Forum | Tue May 14 14:59:47 EDT 2002 | fmonette
Greg, As Dave pointed out, the main reason to bake components is to remove absorbed moisture from moisture-sensitive components. All you need to know on this subject, including the specific bake conditions (temperature and duration) are clearly s
Electronics Forum | Tue May 14 08:04:58 EDT 2002 | robbied
Hi. Does anyone out there know of a way to calculate the surface area of populated PCB's? We build many different types, and until now have been using a water displacement method, which I believe to be fundamentally flawed. Our technique is to drop a
Electronics Forum | Tue May 14 13:18:33 EDT 2002 | Scott B
I think what David was getting at was, as an example. Take a cubic inch of gold. Surface area = 6 sq/in. Volume = 1 cu/in. Water displacement = X. Mass = Y Roll that cube of gold out to a micron thick. Surface area = football pitch. Volume = 1 cu/i
Electronics Forum | Fri May 17 03:04:15 EDT 2002 | Mike Konrad
This conversation reminds me of the old �How Many Engineers Does It Take To�� joke. We manufacturer the ionic contamination (ROSE, SEC) testers and I am not aware of anyone that performs such exacting surface area calculations. Most people use th
Electronics Forum | Tue May 14 18:07:27 EDT 2002 | soupatech
My method is not good if accuracy is an issue. Most of our reels come with a guage on the back. It is not a perfect count but with a good eye you can get within a couple hundred on reels of 5k. On the reels shipped with no guage I usually just hold a
Electronics Forum | Tue May 14 14:48:33 EDT 2002 | fmonette
Hi Dason, Here is some relevant information that you might find useful : J-STD-033, section 7.1.2.2 Dry Box : "Components may be placed in a dry box, capable of maintaining 25+/-5C and less than 10%RH. Nitrogen or dry air may be used." In other w
Electronics Forum | Wed May 15 17:49:44 EDT 2002 | slthomas
We have two E5's, and like them a lot. If money were easier to come by we'd buy one more. Tech. support is excellent, print quality is good (I only have semi-auto clamshell machine prints to compare them to, and it's no comparison). They don't offe
Electronics Forum | Tue May 14 20:25:02 EDT 2002 | russ
Hello All, I've got a little problem here. I have a 456 ball PBGA 1mm pitch, .5mm balls, with .6mm pads on the board. given that the pad size is way to big (S/B .45mm or so)I need any and all advice on how to rework these things without shorting o
Electronics Forum | Thu May 16 15:05:20 EDT 2002 | Hussman69
No need to make rocket science out it. Buy an AOI mchine. If that's too expensive, scrap a board to use as a sample. Can't do that, use a digital camera and snap a couple pix of a good board and make some kick ass work instructions to use. Can't
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