Thermal Evaporation System for Gold Deposition

[Skylar]

I have been reading about resistive evaporation systems & capsule making.

question:

—How do you mask the substrate membrane so that gold is deposited evenly and only where you want it (i.e. not all over the walls of the vacuum chamber or the masking device)?

 

[burdij]

I don't care about the gold that hits the supports and the chamber. That cleans up with acetone. To prevent it from going where I don't want it on the mylar, I make a mask out of aluminum foil. If I were doing a lot of diaphragms, I would make the mask out of brass shim stock. That is available in thicknesses down to 0.5 mils. Either one produces a pretty sharp image on the mylar as the gold atom trajectory is pretty much a straight line radiating outward from the filament.

 

[abbey road d enfer]

Although I've never done it, I know my brother in law did a lot of gold sputtering for lenses. In order to save on the cost of gold, he used an electrode that he put under the lens. I made him a 6kV DC psu. That was in the 70's and he still uses it to this day.