PCB mounting fasteners

That might help, but it doesn't improve compliance and adds resistance, which can warm up the rig and increase cold flow.

John

have

M5

re

er

Seastrom (sp?) wahsers seem great. They've got a large selection of BeCu and Steel washers in all sorts of wavy/beleville patterns. (And I'm not getting any kickback.. I just found them a month ago and am still excited!)

George H. (A man excited by BeCu washers.)

have

M5

Better put a flat washer between the star washer and the PCB. The star = washer=20 will deform the board and cut the copper clad, both bad things.

stuff.

?I have

using M5

the

figure

customer

John, do you suggest a standard Belleville washer, or a Belleville washer with serrated faces, for additional locking power. I've tested the serrated kind in our lab, and it gives a nice pattern of contact into the copper pad on the PCB. Toothed lockwashers scrape into the copper, damaging it, but the serrations on the Belleville washer seem to just press into the copper.

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I haven't tried serrated Bellevilles, so I don't know. My theory suggests a uniformly spread-out pressure, rather than concentrated pressure points, to minimize cold flow. I sort of like plain bellevilles or medium-stiff wavy washers, as they don't damage the board.

The larger the radius of the PCB contact the lower the resistance, so a plain belleville with the big end against the board would probably be good. Fewer, smaller contact points will increase resistance and localized heating.

Soldering is best. I like 1/4" faston tabs, multiple of them for high currents. The mating wires add ballast resistance to even out the currents. They go on and off without messing with nuts and bolts and lockwashers.

John