High-powered light emitting device with improved thermal properties
View Patent ↗A light emitting device includes a first semiconductor layer of a first conductivity type, an active region, and a second semiconductor layer of a second conductivity type. First and second contacts are connected to the first and second semiconductor layers. In some embodiments at least one of the first and second contacts has a thickness greater than 3.5 microns. In some embodiments, a first heat extraction layer is connected to one of the first and second contacts. In some embodiments, one of the first and second contacts is connected to a submount by a solder interconnect having a length greater than a width. In some embodiments, an underfill is disposed between a submount and one of the first and second interconnects.
1. A method of operating a light emitting device, the method comprising:
forming a first semiconductor layer of a first conductivity type;
forming an active region overlying the first semiconductor layer;
forming a second semiconductor layer of a second conductivity type overlying the active region;
selecting at least one of an area, thickness, and material of one of a first contact and a second contact to reduce a temperature gradient within the device during operation to less than about 30 K/mm;
forming the first contact electrically connected to the first semiconductor layer;
forming a second contact electrically connected to the second semiconductor layer; and
operating the device at a current density greater than 143 A/cm 2 ;
wherein a maximum temperature gradient within the device is less than 30 K/mm during operation.
2. The method of claim 1 further comprising selecting at least one of an area, thickness, and material of one of a first contact and a second contact to reduce a thermal resistance per area of the device, defined as a change in temperature divided by a corresponding change in power and area, to below 10 K/W-mm 2 .
3. The method of claim 1 further comprising forming at least one heat extraction layer electrically connected to one of the first contact and the second contact.
4. The method of claim 1 further comprising attaching one of the first contact and the second contact to a submount by a solder interconnect having a length longer than a width.
5. The method of claim 1 further comprising:
attaching one of the first contact and the second contact to a submount; and providing an underfill in a space between the submount and one of the first contact and the second contact.