Q. I work for a company that makes components for use in military hardware. We are using a mil spec polyurethane topcoat, MIL-PRF-85285, on an electronics housing, and I am trying to find a reference indicating that this topcoat is fungus-resistant. The specification does not mention fungus-resistance, and I haven’t run across any fungus-resistance studies referencing this specification. Do you have any suggestions short of testing? M.D.
A. My guess is that if the paint was fungus-resistant, it would be spelled out in the specification. The folks who write these specifications are very thorough about these things. I suggest you ask the paint supplier to be sure. If the topcoat is not fungus-resistant and that property is required, you will have to change paints to one that meets that requirement. Remember to get your customer’s permission to make such a change.
Whelen Engineering was among the thousands of OEMs that sourced its printed circuit boards from Asia until increasing costs led the company to build—greenfield and in-house—America’s first new rigid PCB shop in 15 years.
This article is the third of four parts of a re-publication of the 15th William Blum Lecture, presented at the 61st AES Annual Convention in Chicago, Illinois, on June 17, 1974. Dr. George Dubpernell reviews the history and extent of commercial plating, then delves into the electrochemical science, including potentials, overvoltage and connections to electronics.
Electroplating chemistries evolve to meet electronics industry needs