Re: accuracy of the 720 rule
I read +-7% of the target oxide thickness as the target thickness +-7%. Which if you have a target thickness of 1 mil or .001", +-7% would only be .07 mil or .00007". If this is the typical variation on the 720 rule calculations, I consider it to be extremely accurate. In the machine shop, parts with a designated tolerance call out in the tenths of thousandths also have a temperature call out for the part to be checked at.
As for the parameters that effect coating thickness, Redriver covered it well.
SS
|