The Edwards Agency


Northshore High Tech: Conductive Rubber Technology--the keypad people

silicon rubber

Woodinville resident Jim Herrera blends silicon rubber.
Photo by Gordon Mitchell.

Northshore High Tech by Gordon Mitchell, Ph.D.
From TV remote controls to cash machines, silicone rubber buttons are being pressed. They activate polymer switches, providing a cost-effective alternate to mechanical switches. Conductive Rubber Technology (CRT) fabricates these switches in the form of custom keypads for well-known equipment manufacturers such as Tektronix.
   The company started in 1979 and now employs 30 people in their Bothell office. Sales are handled by representatives throughout the U.S. Keyboards are fabricated in China and Malaysia.
   Polymer switch keyboards were first developed in Japan, then as labor costs increased, fabrication facilities moved to Asia. Computer-aided design technology lets CRT design products that use these offshore facilities--designs are sent via computer files to factories that make the products and ship to Bothell.
   During my visit, Brad Lawrence, the company president, proudly showed me prototype design capabilities starting in the engineering area. Here, designers work with designs provided by clients. For example, a client might provide the shell of a new TV remote control. CRT polymer switches are fit into the holes of the shell and touch contacts on the circuit board. After a computer-based design is completed, it is used to produce a precision mold for the new parts.
   Dyes are added to a silicone material which is baked in the mold that shapes the final product. After completion of the prototype, the design files are sent via the Internet to an Asian factory.
   Challenges in the design process involve making inexpensive keyboard switches feel good and last many years. The "feel" of switches can actually be measured. At CRT, this is done by measuring displacement and force during the travel of the switch and its rebound. Engineers use these measurements to quantify switch performance.
   Isn't this company exporting good U.S. jobs? Brad explained that the polymer key process started overseas and really never existed in this country until the company founder began importing keypads. CRT gives U.S. manufacturers access to this technology for their low-cost products, often saving a factor of 5 or 10 compared to mechanical switch designs.

Gordon Mitchell has a background in the engineering management of high tech organizations. He is a principal of Future Focus, a Woodinville company that provides an unusual investigative service, working with commercial clients who suspect they may be victims of electronic eavesdropping. Future Focus performs specialized inspections to locate bugs and taps that may have been installed by unethical competitors or dissatisfied employees. Gordon can be contacted at 489-0446 or via e-mail at