Toshiba Unveils 'Industry's Smallest' White LED Chip
Toshiba Corp developed what it claims is the industry's smallest (0.65 x 0.65mm) white LED for lighting applications.
With the company's wafer-level CSP (chip scale package) technology, the footprint of the LED, "CSP-LED," is 50% or more smaller than those of its competitors' LEDs. Because the new LED allows to drastically reduce the size of light source, it enables to design lighting equipment more freely as well as to make use of space in which a conventional light source cannot be installed.
Toshiba will start shipping samples of the LED in late April 2014.
Toshiba has been mass-producing white LEDs using GaN-on-Si technology, which forms a gallium nitride (GaN) layer on a 200mm-diameter silicon (Si) wafer. They can be manufactured at low costs, compared with white LEDs using a sapphire wafer. Currently, the company is producing the white LEDs at a rate of 50 million to 100 million units per month.
Using core technologies of semiconductor unit
This time, Toshiba applied core technologies of its semiconductor unit such as packaging and Cu multi-layer wiring technologies to white LEDs, it said. Specifically, the company used its wafer-level CSP technology, which is used for installing RF devices, etc.
The technology forms wiring and pins and conducts resin sealing at the wafer level, and, then, the wafer is separated into chips. To apply this method to white LED, Toshiba newly developed a device structure that enables to directly pull out copper (Cu) electrodes from the reverse side of the light-emitting layer without using wire bonding.
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