Goldeneye reduces process steps with EpiChip LED
A process to produce a thin-film "epi-only" chip without the need to bond to a submount could result in a simplified and lower cost LED manufacturing process.
The so-called "EpiChip™" technology produces a chip that consists entirely of epitaxial material i.e. there is no growth susbtrate present. Unlike other "thin film" technologies, where the growth substrate is also removed, the EpiChip is not bonded to a submount.
"The free-standing nature of the EpiChip™ is a key advantage," explains Ken Livesay, Marketing and Sales Manager for Goldeneye, "since it eliminates the necessity for the step that bonds existing devices to a submount, as well other process steps, resulting in reduced consumables, a boost in yield, and ultimately lower costs and more reliable parts." Livesay also says that EpiChip enables some significant advantages in packaging that will become evident as the company makes further announcements.
“The EpiChip™ is the ultimate simplification in LED design, in that it is simply all epi,” says Scott Zimmerman, Goldeneye’s VP of Technology. “It provides the lowest thermal resistance, highest extraction efficiency, lowest cost of manufacturing, and maximum flexibility in packaging.”
The new device marks the introduction of several Goldeneye innovations, including the use of an economical proprietary thick epitaxial layer. Livesay says that the thick epi layer ranges from 10 microns to 50 microns depending on die size and application. "The use of thicker epi enables structural integrity, improved crystal quality, improved current spreading, and physical separation of contact surfaces for subsequent packaging."
The company is working with a range of nitride-based materials. Blue and Green EpiChip™ LEDs up to 1 mm2 have been produced. A wide range of die configurations, sizes and colors, including amber and white, are being developed. Typical output levels at 20 mA exceed 5 mW at 520 nm for 200 x 200 micron emitters. Devices from 350nm to 585nm have been demonstrated. The company expects to have selected products ready for commercial introduction by the third quarter of 2008.
However, notes Livesay, Goldeneye does not have plans at this time to enter the LED business by selling bare die EpiChips. "This technology will be used in complete packages from Goldeneye," he says.
The EpiChip™ technology platform was developed initially for use in Goldeneye’s patented light recycling systems. However, says the company, the benefits of the EpiChip™ quickly became evident and the company now has multiple patents pending covering other applications including automotive, architectural, and general lighting.
“We have spent the last several years putting a wide range of technologies together both from an IP and process standpoint,” says Goldeneye CEO Bill Livesay. “Over the next 12 to 18 months we intend to roll out a series of products utilizing the EpiChip™ that will have a strong impact on the solid state lighting and display industries.”