| 摘要 |
The LEDs (72,74) are fabricated as a monolithic structure on a semiconductor wafer and are separated by sawing, cutting etc. Selected non-adjacent LEDs are removed from the diced monolithic wafer and transferred to a heat dissipating substrate in a single process step whilst maintaining their relative positions and separations. An array of lenses 122, 124 or reflectors is also transferred onto the LED assembly formed on the heat dissipating substrate. The LEDs typically have dimensions of 25-100 microns which reduces losses due to internal reflection and increases light output. The density of the LED assembly on the heat dissipating substrate is smaller than the density of the LEDs as formed on the monolithic wafer, maintaining the relative positions and orientations of the transferred LEDs in this way ensures that heat can be effectively removed from the LEDs. The manufacturing efficiency is improved in comparison with conventional pick and place techniques where individual LEDs from the monolithic wafer are selected and transferred to an LED array substrate in a sequential manner. |
