This post was written by Keith Dawson for UBM Tech’s community Web site All LED Lighting, sponsored by Philips Lumileds. It is archived here because the All LED Lighting site has gone dark. This material is Copyright 2013-2015 by UBM Americas.

2013-12-16

Monday Roundup: Sticky

This week: Intematix's ChromaLit Linear remote phosphor, solving sticky adhesive issues, and SSL companies get Department of Energy tax credits.

Cree, Osram Sylvania awarded DoE tax credits
The two lighting companies share in $150 million in DoE-awarded tax credits to advance clean energy manufacturing. Cree and Osram Sylvania are the only SSL-focused companies among the 12 winners; others produce products and technologies for air conditioning, automobiles, batteries, energy distribution, hydropower, and wind power.

Cree will receive $30 million in tax credits to expand its manufacturing capacity in Durham, N.C., and Racine, Wis. Osram Sylvania was awarded an undisclosed amount of tax credits. Oddly, the official DoE list of selected projects reads "Not Authorized for Public Disclosure by the Taxpayer" for both amount and manufacturing location. But the purpose of the award was made plain: It is to expand production capacity for the company's "energy-efficient and cutting edge single-point LED systems for automotive low/high beam projectors."

Shuji Nakamura is honored
The inventor of the blue and white LEDs that enabled the lighting revolution in which we are now engulfed, Shuji Nakamura, has been named "Person of the Year" by Lux and has been inducted into Electronic Design's Engineering Hall of Fame. Nakamura is a professor at the Materials Department of the College of Engineering, University of California, Santa Barbara, and is a co-founder of Soraa.


Intematix's ChromaLit Linear. (Source: Intematix)

Intematix's ChromaLit Linear remote phosphor
The phosphor company announced the availability of ChromaLit Linear, "a remote phosphor offering uniform luminance over any length" -- up to 2,500 lm per foot. The product received a 2014 Lux Award for Light Source Innovation of the Year, and will be among those listed in the IES Progress Report this year. Remote phosphor designs can feature high efficacy and good color stability (because the phosphor is far from the heat source). Intematix claims that ChromaLit Linear can be used in luminaires having a system efficiency of 130 lumens per Watt.

One unique claim made for this phosphor is a white appearance when in the off state, instead of the strong yellow color that dimmed the commercial prospects of the Philips L Prize bulb. Margery Conner's review of the ChromaLit Linear calls its off color a "very pale yellow." The Klauf Light Bar, whose Kickstarter project we discussed last April, uses a different Intematix remote phosphor and appears egg-yolk yellow when off, according to photos of prototypes. (I contributed to the Kickstarter project and am still awaiting delivery of my one and a half feet of Klauf Light Bar, which was initially promised for August.)

Solving sticky adhesive issues
Design News has a most informative post on the ins and outs of choosing adhesives when putting together LED assemblies with, for example, encapsulant and a silicone lens. Outgassing from the adhesives can result in premature dimming and color shift of LED die. The author, Ed Fisher of adhesives manufacturer Henkel Corp., explains in some detail the compatibility testing his company has done with adhesives of various types, cured and uncured, in contact with LED die and far from them. The good news is that the problems of color shift can be well controlled by choosing compatible adhesives for the application at hand. The article is "Assessing Compatibility of Adhesives for LED Assembly."

Related posts:

— Keith Dawson Circle me on Google+ Follow me on Twitter Visit my LinkedIn page, Editor-in-Chief, All LED Lighting