High-performance LED fabrication
View Patent ↗High-performance light-emitting diode together with apparatus and method embodiments thereto are disclosed. The light emitting diode devices emit at a wavelength of 390 nm to 470 nm or at a wavelength of 405 nm to 430 nm. Light emitting diode devices are characterized by having a geometric relationship (e.g., aspect ratio) between a lateral dimension of the device and a vertical dimension of the device such that the geometric aspect ratio forms a volumetric light emitting diode that delivers a substantially flat current density across the device (e.g., as measured across a lateral dimension of the active region). The light emitting diode devices are characterized by having a current density in the active region of greater than about 175 Amps/cm 2 .
1. An LED package comprising:
a ceramic substrate having a substrate top surface;
a plurality of traces overlaying said substrate top surface;
a plurality of contacts, each contact being electrically connected to one of said traces;
a reflective material disposed over at least a portion of said traces, said reflective material not extending above said plurality of contacts; and
a flip-chip LED die having LED contacts said LED contacts contacting said plurality of contacts.
2. The LED package of claim 1 , wherein said ceramic substrate is electrically isolated from said plurality of traces.
3. The LED package of claim 2 , wherein said LED chip is volumetric.
4. The LED package of claim 2 , wherein said ceramic substrate consists of an insulating material.
5. The LED package of claim 4 , wherein said substrate comprises at least one of a ceramic, oxide, or nitride.
6. The LED package of claim 1 , wherein said traces have a first footprint area and said contacts have a second footprint area, wherein said second footprint area is smaller than said first footprint area.
7. The LED package of claim 1 , wherein said reflective layer forms a surface and said contacts protrude above said surface.
8. The LED package of claim 1 , wherein said LED die fully covers said contacts.
9. The LED package of claim 1 , wherein said traces are covered completely.
10. The LED package of claim 1 , wherein said traces and said contacts comprise copper.
11. The LED package of claim 1 , wherein the reflective material does not cover said contacts.
12. The LED package of claim 1 , wherein said contacts cover a fraction of said traces and wherein said reflective material covers another fraction of said traces.
13. A method of preparing an LED package comprising:
disposing a plurality of traces over a ceramic substrate;
disposing a plurality of contacts over said substrate such that each contact is electrically connected to one of said traces;
disposing a reflective material over at least a portion of said traces, said reflective material not extending above said plurality of contacts; and
flip-chip mounting an LED die having LED contacts over said substrate such that said LED contacts contact said plurality of contacts.
14. The method of claim 13 , wherein said plurality of traces is disposed in a first layer, and said contacts are disposed in a subsequent second layer.
15. The method of claim 14 , wherein said reflective material is disposed in a third layer subsequent to said second layer.
16. The method of claim 13 , wherein said traces have a first footprint area and said contacts have a second footprint area, wherein said second footprint area is smaller than said first footprint area.
17. The method of claim 13 , wherein said reflective layer forms a surface and said contacts protrude above said surface.
18. The method of claim 13 , wherein said LED die fully covers said contacts.
19. The method of claim 13 , wherein said traces are covered completely.
20. The method of claim 13 , wherein the reflective material does not cover said contacts.
21. The method of claim 13 , wherein said contacts cover a fraction of said traces and wherein said reflective material covers another fraction of said traces.