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Polysulfone electroplating for EMI/RFI shielding.
I have some difficulties to find US based companies specializing in Polysulfone electroplating for EMI/RFI shielding.
I would be very grateful if you could send us the names, addresses,Tel and Fax of some of them.
Thank you for your help
Best RegardsDr. Bouarfa Mahi
Our Directory of Equipment contains several primary suppliers and distributors.
Falls Township, Pennsylvania
"Electroless Copper and Nickel-Phosphorous Plating"
from Abe Books
Are you referring to plating a metal over Polysulfone plastic for the purpose of EMI/RFI shielding a device within? If so then you have chosen a difficult plastic to activate, as polysulfone is well known for its inertness. I have rendered it active for Sn/Pd catalysis followed by electroless Nickel or Copper by first treating it in hot 180° F 10% KOH for 2 min. then boil it in H2SO4/K2Cr2O7 with just enough water to fix the boiling point at 250'F for 1 min. Rinse then apply the Pd catalyst via Sn oxidation. There are off the shelf chemicals/processes for each of these steps.
If you're still having difficulties, I help set up an automated line for a large electronics mfg. firm in the Pacific Northwest some years ago. The line was set up with processes for the application of electroless nickel over electroless copper on injection-molded ABS, various injection-molded structural foams, polysulfone, Ultem, and polycarbonate substrates. As that company elected to get out of that business, I guess its okay to suggest that if you find a shop that's willing, the work (injection-molded polysulfone) must first be stress-relieved in an oven for approx. 12 hours at about 175 degrees F. You can test for doneness by immersing a part (if not cost-prohibitive) in Acetone [affil. link to info/product on Amazon]. If its done, nothing will happen. If its not done, the part will literally fall apart. Then the parts are immersed in a 50% solution of DMF and water heated to 125 degrees F. to swell the skin of the plastic. Rinse in clean water and load for plating. The process we utilized employed a chromic etch, neutralizer, sensitizer, Sn/Pd catalyst, accelerator, electroless copper, Pd activator, then finally the electroless nickel. Hope this helps!Steve Clay
I would like to know if anyone out there has data on the Dielectric Constant and Dissipation factor of Polysulfone at high frequencies i.e above 1 GHz. Thank you.Yvan Araktingi