Electronics manufacturers are gaining interest in a formable shield that protects against electromagnetic interference and limits radiation emissions.
Four cellular telephone makers and two equipment contract manufacturers are testing Form/Met plastic shields. Shielding For Electronics Inc. of Sunnyvale, Calif., forms the shields into a variety of shapes to protect devices from EMI and radio-frequency interference. A business unit applies aluminum vacuum metalization on one or both sides of a thin, thermoformed film of polycarbonate, PVC or glycol-modified PET, said Rocky Arnold, SFEI president and chief executive officer.
While still small, “our business for the Form/Met product line is up more than 100 percent over last year,” said John Millis, SFEI vice president of business development. Patent applications and other Form/Met product developments are pending.
Form/Met can eliminate the need for in-house or contract part painting or plating. Usually, a Form/Met shield can provide EMI protection for about 95 percent of current electronic products, SFEI said.
Optional applications include conformal shields inside a plastic housing, over multiple areas of printed circuit board or over a single area of a larger PCB.
Higher frequencies and more cross-talk push developers toward such solutions.
Form/Met “will become an industry standard,” eliminating gaskets and being more consistent than spray paint, said Josh Hoyt, a product-development consultant in Portland, Ore., with Flextronics International Ltd.'s design business unit. “I am looking at the benefits from an overall product-development perspective.”
Hoyt said the use of Form/Met shifts responsibility for EMI solutions to circuit-board designers upfront, rather than mechanical engineers in later development stages.
“You only occasionally run across things that can make a fundamental shift,” Hoyt said. “When you start talking about impacting a manufacturing line, the dollars [are] big and implications huge.”
A group in Flextronics' San Jose, Calif., headquarters is evaluating Form/Met technology.
A Form/Met part, as a separate, inserted component, is cost-competitive with paint, said Chuck Villa, executive vice president of business development with United Plastics Group Inc. in Westmont, Ill.
“We anticipate less fall-off in the process, which equates to lower cost and additional machine capacity available to sell,'' Villa said.
A Form/Met shield conforms to the inside of an enclosure in a shape designers are “unable to duplicate in metal at any cost,” said Mark Siminoff, a senior mechanical engineer in the Palo Alto, Calif., office of Ideo Product Development.
Apple Computer Inc. of Cupertino, Calif., used a Form/Met shield inside a clamshell for an early version of its wireless AirPort local-area-network base station.
Formalizable and metalizable, shortened to Form/Met, describe the production steps in a patent issued in 1998 to John Gabower, then-majority owner of Vacuum Platers Inc., a decorative metalization firm in Mauston, Wis.
SFEI acquired the patent and Vacuum Platers in May 2000 and created separate Mauston business units for decorative metalization services and EMI shielding. SFEI operates one panel forming press with a 30-by-30-inch bed and subcontracts for production-volume forming.
The SFEI units employ more than 40 in Mauston. Another 10 work in Sunnyvale and field sales positions. The Sunnyvale site has design capabilities and prototype laboratories for tooling, thermoforming and testing.