I am working with an AL 1050 heater plate for a semiconductor wafer.
When a wafer is put down on the plate, it picks up tiny, but unacceptable amounts of iron (FYI - AL 1050 has only 0.4% max iron content).
We are using anodizing as a means to "trap" iron under the oxide layer.
This has proven to be a big improvement over bare aluminum, but we are still not where we need to be.
The part is currently cleaned after anodizing in an ultrasonic deionized water bath. It has been suggested to use a nitric acid "chemical cleaning" instead.
Does anyone have experience with this kind of cleaning post-anodize? Will it damage the surface at all? Any alternative cleaning methods that will "pick" iron out of the surface?
