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Preparation of titanium for sputter coating with silver or nickel

I want to use thin (5 micrometer) foils from pure titanium as part of a particle detector.
To be able to solder the foils on a supporting frame made from printed circuit board, I need to coat it (only partially!) with a thin silver layer with very good adhesion.

Our lab sputter coated some test samples with a 0.5 to 1 micrometer thick silver layer. The adhesion of the silver to the titanium was tested by disrupting the soldered foil from the PCB.

It varied from poor to good, but is not predictable. What is a right preparation of the titanium to get a strong adhesion of the sputtered silver? (We only cleaned the foil with ethanol.)

Are there other processes which provide silver (or nickel) layers with good adhesion?

Rudolf Doelling
research institute -Aargau, Switzerland
2003

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Titanium is difficult to activate, but it can be reliably nickel electroplated with excellent adhesion by a process that involves plating, followed by diffusion, followed by replating.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003

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Thanks for the fast comment (and all the letters already published). I am not familiar with electroplating. I am in doubt if it is applicable here.
On the one hand the titanium foil is not easy to handle because it is so thin/has a strip pattern etched (through)/should not buckle. Processing can only be done when tensioned over a frame.


On the other hand the silver or nickel coating should only extend to a limited region of the surface. So sputter deposition seems easier to me from the handling point. What chemical or physical pretreatment can be applied?

From other letters I get the impression that removal of the oxide layer is crucial. Is diffusion by heating (to what temperature?) a useful post-treatment also in the case of sputter deposition?

Rudolf Doelling
research institute - Switzerland
2003