Reducing the variation of far-field radiation patterns of flipchip light emitting diodes
US6563142B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 11, 2001 |
| Grant date | May 13, 2003 |
| Priority date | — |
| Expiry date | Jul 11, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10H20/82
Abstract
The present invention relates to reducing the spatial variation in light output from flipchip LEDs and increasing the consistency in light output from LED to LED in a practical manufacturing process. The present invention introduce appropriate texture into the surface of reflective layer to reduce spatial variation in far-field intensity. At least two reflective planes are provided in the reflective contact parallel to the light emitting region such that at least two interference patterns occur in the light exiting from the LED. The reflective planes are separated by an odd integral multiple of (&lgr;n/4) where &lgr;n is the wavelength of the light in the layer between the active region and the reflective contact, resulting in compensating interference maxima and minima, a more uniform distribution of light, and increased consistency in light output from LED to LED.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.