Californian LED die maker Bridgelux has introduced a range of multi-die power LEDs up to 2,000 lm.
"One of the things we have focused on is a consistent product," v-p of business development Keith Scott told Electronics Weekly. "The 800 lm device you buy today will match the 800lm product you buy in five years. OEMs will have no problem matching from luminair to luminair."
To provide isolated heatsinks with high thermal conductivity, the firm has built isolation into the individual die. "All there is in the package is the die, the die attach, and the aluminium substrate," said Scott. "Thermal conductivity is in the range 0.5 to 0.8°C/W."
Bridgelux has opted to cover blue die with a silicon/phosphor mixture rather than phosphor-coat each individual die. "The approach we use really enhances uniformity," said Scott.
There are two packages, one in the traditional 'star' style offered with output up to 400 lm, and a slightly larger rectangular style available in 800, 1,200, and 2,000 lm versions.
Cool, neutral and warm white options are available, and Scott is particularly proud of the warm white: "These have a colour rendering index in the 82 to 83 range."
Efficacy of the arrays is in the 55-75 lm/W range depending on light output and hue. This is not state of the art, but Scott points out Bridgelux' aim is low-cost lumens rather than extreme efficacy: "Cree will sell you a 110 lm/W device, but it will cost you $4," he claimed.
"There are a lot of 65 lm/W devices, but the majority of production in the market today is in the 50-55 lm/W range."
With Cree and Lumileds, Bridgelux is the third maker of Blue power LED die in the US. Bridgelux has been supplying bare die to Far Eastern LED makers.
Until the end of December when they settled, Cree and Bridgelux were tangled in litigation.
As part of the settlement, Cree granted Bridgelux a license to the Cree and Boston University patents at issue in the litigation, and Bridgelux agreed to pay a license fee and royalties.
In addition, a supply deal means Cree will become a "significant supplier" to Bridgelux. said a joint statement. Other terms of the settlement are confidential.
See also: Electronics Weekly's roundup of content related to LEDs, with a special focus on both white LEDs and coloured LEDs:
LED technology - White LEDs
LED technology - Coloured LEDs
LED technology - LEDs general
LED technology - OLEDs
LED technology - LEDs Lighting