HP unveiling two surface-mount LEDs

Electronic News, May 20, 1996 by Sarah Cohen

Palo Alto, Calif.--Hewlett Packard Company today is rolling out two new surface-mount light emitting diodes (LEDs), the SunPower LED series--which HP claims is the industry's brightest LED--and a flip-chip packaged LED which is described as "more reliable" than previous generations of the same product.

Electronic News has also learned that within a year HP plans to come to market with a gallium nitride LED in a bright blue color, a move that would position the company to develop a range of full color LED displays to be used in point-of-sales applications.

Dan Kolody, HP's worldwide SMT marketing manager, optoelectronics division, noted that red, green and blue mix to form white, and these colors also mix to form the spectrum of colors. HP already manufactures LEDs with bright red light, and other companies at this time make relatively expensive LEDs in a bright blue and green, said Mr. Kolody.

However, there are some restrictions to making full color LEDs today, Mr. Kolody explained. Blue and green light right now cost about a dollar per diode, and the technology to make blue light cheaper is still in the early stage. Also, the epoxy in blue light degrades after a short period of time. Mr. Kolody noted that it will likely be about two years before full color LEDs are brought to market.

Meanwhile, HP's newest LED diode, the SunPower LED series comes in amber, orange and reddish-orange colors. The LEDs have luminous intensities of 65 mcd at 20mA for amber and orange, and 50 mcd for reddish-orange--all typical at 20mA drive current. Using HP's aluminum indium gallium phosphide (AllnGaP) material, the company said designers and manufacturers need only four of the new LEDs instead of 12 gallium phosphide LEDs to achieve equivalent illumination.

The elimination of the wire on HP's new flip-chip series LEDs reduces the size and packaging of this LED per chip. It also increases reliability, according to Mr. Kolody, because faultiness within an LED is usually due to deterioration of this wire. The new flip-chip LEDs are qualified to 1,000 temperature cycles at full operating power, as opposed to 100 temperature cycles for conventional wire-bonded units, the company said.

The flip-chip LED series is priced at 10 cents per piece, while the HP SunPower Chip LED series is priced at 20 cents per piece. Both are available now.