Platinum Metals Rev., 1959, 3, (1), 16
Rhodium Plated Printed Circuits
Printed circuit techniques based on conventional etched, copper-clad laminates are well established for the manufacture of multi-way switches. Such techniques greatly simplify construction and reduce manufacturing time and cost.
Electrode posited rhodium is generally accepted as the most satisfactory means of providing such switches with wear-resistant, tarnish-free contact surfaces. Used in conjunction with suitable gold-alloy or palladium-alloy brush materials these switches give low values of contact resistance and electrical noise coupled with a surprisingly long life.
The illustration shows the nine-inch stator of a 200-way switch to be used in telemetry equipment. The rhodium has been deposited on the contact surfaces of the 200 sectors as well as on the two slip rings in the centre. Originally the stator had an outside band of copper linking the sectors, as well as a connecting strip to the two slip rings, to permit plating.