Back in 2005 a customer left a question on our website and it was answered by one of my solder heroes. Here is the Q&A:
Question: “With regard to Indium Corporation's indium sulfamate plating bath… …can it be deposited onto platinum-gold thick film inks? Namely DuPont solderable inks on 96% alumina?”
Answer: “Thick film inks often contain low melting glass frit particles which enhance bondability to the alumina substrate. Solderable thick film inks are designed so that the glass particles do not reside on the surface, thus allowing the solder to wet. As in solder wetting, having a glass frit-free particle surface will also allow electrodeposition of any metal. Therefore if the ink is solderable it should be plateable.”
I learned from this answer so I thought it would be good to share with you. Call me or email me to discuss your questions.