High voltage low current surface-emitting LED
View Patent ↗A monolithic LED chip is disclosed comprising a plurality of junctions or sub-LEDs (“sub-LEDs”) mounted on a submount. The sub-LEDs are serially interconnected such that the voltage necessary to drive the sub-LEDs is dependent on the number of serially interconnected sub-LEDs and the junction voltage of the sub-LEDs. Methods for fabricating a monolithic LED chip are also disclosed with one method comprising providing a single junction LED on a submount and separating the single junction LED into a plurality of sub-LEDs. The sub-LEDs are then serially interconnected such that the voltage necessary to drive the sub-LEDs is dependent on the number of the serially interconnected sub-LEDs and the junction voltage of the sub-LEDs.
1. A LED chip, comprising:
a plurality of sub-LEDs mounted on a submount, wherein said sub-LEDs are formed from a single junction LED;
an insulator layer between said submount and said sub-LEDs; and
electrically conductive and electrically insulating features serially interconnecting said sub-LEDs such that an electrical signal applied to said serially interconnected sub-LEDs along said electrically conductive features spreads to said serially interconnected sub-LEDs, wherein said electrically conductive features comprises a plurality of connector traces serially interconnecting said sub-LEDs.
2. The LED chip of claim 1 , wherein the voltage necessary to drive said sub-LEDs is dependent on the number of said serially interconnected sub-LEDs and the junction voltage of said sub-LEDs.
3. The LED chip of claim 1 , wherein said sub-LEDs are formed from a single junction LED by removing portions of said single junction LED.
4. The LED chip of claim 3 , wherein said sub-LEDs are formed from a single junction LED by isolation implants.
5. The LED chip of claim 3 , wherein the active area utilization ratio is greater than 50%.
6. The LED chip of claim 3 , wherein the active area utilization ratio of said single junction LED active region is greater than 75%.
7. The LED chip of claim 1 , wherein said sub-LEDs are flip-chip mounted on said submount.
8. A LED chip, comprising:
a plurality of sub-LEDs mounted on a submount;
a plurality of bottom contacts, each of which is between one of said sub-LEDs and said submount;
connector traces serially interconnecting said sub-LEDs; and
insulating features to insulate portions of said sub-LEDs from said connector traces.
9. The LED chip of claim 8 , wherein said the drive voltage is dependent on the number of said serially interconnected sub-LEDs and the junction voltage of said sub-LEDs.
10. The LED chip of claim 8 , further comprising an insulating layer between said sub-LEDs and said submount.