Delphi's LED Illumination Capability Brings OEMs Innovative Options to Differentiate Vehicle Interiors

TROY, Mich., Aug. 31, 2005 -- Delphi Corporation is offering automakers seeking an element of differentiation to their vehicle interiors an innovative lighting technology that takes advantage of the growing prominence of LED applications.

Delphi is bringing to customers unique answers to their illumination expectations through customized concepts utilizing light emitting diode (LED) technology, responding to vehicle manufacturers' ongoing need to provide distinctive, leading-edge interior designs. Delphi's LED illumination capability will be highlighted at the 61st International Motor Show (IAA) in Frankfurt.

Taking illumination into new areas is one way to do that, noted Dieter Barowski, European engineering director at Delphi's Packard Electric division. Delphi's LED illumination capability in Europe does that, integrating components into conventional wiring and also on flexible printed circuits, the latter allowing for applications where in-vehicle packaging presents challenges.

"Interior illumination has been historically limited to only a few areas, in places such as dome and reading lamps, lighted visors, and the back lighting of various components," Barowski said. "With LEDs and our ability to route flexible printed circuits into places where space is a premium opens up a number of new illumination options inside the vehicle."

Historically, the use of LEDs, though widely seen for years in numerous non-automotive environments, has been limited in vehicle applications to center/high-mounted stop lamps and, most recently, traditional brake lighting and side-panel markers.

Delphi, though, is using integrated LEDs to expand the possibilities, illuminating doorsills, reading lamps, interior courtesy lights, and sun visors. Other applications include LEDs in B- and C-pillar illumination, color change, door handles, and interior roof and other ambient lighting, among others. Delphi has also developed an ultra-thin application for the central high-mounted stop lamp that measures only 6 mm in thickness, allowing automakers greater flexibility for installation with its ability to be mounted directly to the window.

Due to their exemplary durability and low heat generation, along with their longer life cycle and lower power consumption compared to incandescent lamps, LED integration affords vehicle manufacturers strong cost-reduction and improved reliability potential. LEDs offer a high degree of uniform illumination, and in applications such as vanity mirror and reading lamp placement, provide warm white light with outstanding color performance.

"With flexible printed circuits, or 'Flat Wire' utilization, we have created low-profile illumination possibilities that reduce the number of electrical interfaces and assembly complexity, and increase the OEMs' packaging possibilities, a critically important point as one considers the constraints posed by growing vehicle content and the naturally tight routing spaces in which LED illumination is being introduced," said Reinhard Felgenhauer, engineering supervisor, fiber optic and illumination at Delphi Packard Electric.

Flat wire, a general industry term used to describe flexible printed circuits and flat cable, consists of copper conductors insulated in plastic, and comes in several forms. Those include flexible printed circuits (FPC), which are made from conductive patterns created by a print-and-etch process from a copper polymer substrate and then covered by plastic laminate or conformal coating. Flexible flat cable (FFC) consists of flat copper conductors rolled or cut and laminated between plastic film.

A longtime, multiple-decade leader in the technology, Delphi has pioneered several flat wire milestones in the last few years, including the world's FPC headliner harness in 1999, used on a 2000 model year vehicle for a European OEM. This innovative solution replaced the conventional cabling for front and rear interior lighting, illuminated sun visors, power sunroof and microphones.