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Chrome plating - anode slurry

January 1, 2012

Q. Hello all.
I am interested in chrome plating and one of its fatal flaws is the line of site LOS dependence on the anode. I have an idea to overcome this and would like to hear your opinions:

STEP 1:
Take lead powder and peroxide it in 5% sulfuric acid, to create protective layer on each particle.

STEP 2
Load the chromic acid solution with powder prepared in step one.

STEP 3
Vigorously agitate solution while performing chroming operations.

The theory is that the electrical conductivity of the solution becomes significantly increased by adding millions of micro anodes throughout the solution. The extent to which agitation will be required will depend on the size of the lead peroxide powder. Smaller particles will take longer to settle, hence less agitation will be required. Please note that the size of particles I am referring to here is on the order of microns.

What do you all think?

Clearly analysis needs to be done to determine optimal particle density. I'd suspect that to yield significant benefits total volume of the particles would need to be about half of the total volume of the solution.

Igor Petrusky
- Stuart, Florida, USA

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Adding micro or nano particles may increase the conductivity of the solution but they do not becomes anodes.
Unfortunately, the areas that face the anode will still plate heavier than the low CD areas.
Experimentation is the only way to find out.

I think that you would be better off spending your time on developing shields, robbers and aux anodes.

I am a great fan of conforming mesh anodes as they can be tweaked to get the chrome to go where you want it as well as it allows a significantly higher plate rate because of the smaller anode to cathode distance.

James Watts
- Navarre, Florida
January 5, 2012