lessons taught

I remember asking Harris for a sample on an 74HC5xx part once. They refused saying these were not complex parts. lol

Meaning, I take it, "If you can't afford to buy a 50-cent chip from Digikey, you aren't a serious customer."

Cheers

Phil Hobbs

A 50 cent chip at a DOD contractor costs over $100 and takes a bunch of my time. You would think Harris would get that, but I guess different divisions.

I was actually told that it costs $100 per line item and that was in the

This would have been magnet wire, what was left over on a spool from MWS.

I'm not sure what hard drawn wire is, but I'm guessing more than the

George H.

Take the four bits out of your pocket?

I would think that if you're using Plutonium wires, conductivity isn't going to be your biggest problem.

PCB layout people have enough things to worry about already, without dealing with criticality.

I always let our layout people know what the critical nets are.

If they're already critical, everybody nearby is dead anyway.

Cheers

Phil Hobbs

Measure, mark, cut 1st approximation, re-measure, mark, trim, verify measurement,

works pretty well IRL. "Measure twice cut once" is too open-loop--lots of mistakes that way.

Cheers, James Arthur

Cheers, James Arthur

On Saturday, May 30, 2015 at 5:41:29 PM UTC-4, Lasse Langwadt Christensen w rote:

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Thanks Lasse, Though my computer had a hard time viewing that document.

So hard annealed is 2-3% higher in resistance.

George H.

Don't know about magnetic layers, but I worked on a machine with 18 layer boards with an omega layer for termination resistors. It saved a lot of space using ECL logic.

We have a guy working with us that came from a tyco division that makes boards, they go up to 64 layers. Lots of mil boards are done there.

Jamie

Embedded resistors and caps (especially power planes) were a big thing once. Do people still do that?

The problem past 10 or so layers is impedance control. To keep reasonable traces, even 50 ohms, either the traces become impossibly skinny, or the board thickness explodes.

We prefer 6 or 8 and have done a few at 10, required to get the signals out of a big BGA. I actually did a TWO layer board earlier this year!

And hard to bend.

I see board houses offering "embedded components" here and there. Never been brave enough to ask for a quote...

Tim