Contacting scheme for large and small area semiconductor light emitting flip chip devices
View Patent ↗A light emitting device includes a layer of first conductivity type, a layer of second conductivity type, and a light emitting layer disposed between the layer of first conductivity type and the layer of second conductivity type. A via is formed in the layer of second conductivity type, down to the layer of first conductivity type. The vias may be formed by, for example, etching, ion implantation, diffusion, or selective growth of at least one layer of second conductivity type. A first contact electrically contacts the layer of first conductivity type through the via. A second contact electrically contacts the layer of second conductivity type. A ring that surrounds the light emitting layer and is electrically connected to the first contact electrically contacts the layer of first conductivity type.
1. A light emitting device comprising:
a layer of first conductivity type;
a layer of second conductivity type;
a light emitting layer disposed between the layer of first conductivity type and the layer of second conductivity type;
a via formed in the layer of second conductivity type, the via extending to the layer of first conductivity type;
a first contact electrically contacting the layer of first conductivity type through the via;
a second contact electrically contacting the layer of second conductivity type;
a submount interconnect electrically contacting the first contact, wherein at least a portion of the submount interconnect overlies the second contact; and
a ring electrically contacting the layer of first conductivity type, wherein the ring surrounds the light emitting layer and is electrically connected to the first contact.
2. The light emitting device of claim 1 further comprising an insulating layer interposing the submount interconnect and the second contact.
3. The light emitting device of claim 1 wherein the submount interconnect comprises solder.
4. The light emitting device of claim 1 further comprising:
a submount connected to the submount interconnect;
a leadframe connected to the submount; and
a lens underlying the submount.
5. The light emitting device of claim 4 wherein the leadframe comprises:
a first polarity lead comprising two legs; and
a second polarity lead comprising two legs.
6. The light emitting device of claim 4 further comprising:
a body overlying the submount, wherein the body and the lens comprise transparent epoxy.
7. The light emitting device of claim 1 further comprising:
a board connected to the submount interconnect, wherein the board comprises a trace coupled to the submount interconnect.
8. The light emitting device of claim 1 wherein the device has an area less than about 0.2 square millimeter.
9. The light emitting device of claim 1 wherein the layer of first conductivity type and the layer of second conductivity type comprise gallium and nitrogen.
10. The light emitting device of claim 1 wherein the layer of first conductivity type and the layer of second conductivity type comprise aluminum and phosphorus.
11. The light emitting device of claim 1 wherein the via has a width ranging from about 2 μm to about 100 μm.
12. The light emitting device of claim 1 wherein the via has a width ranging from about 10 μm to about 50 μm.
13. The light emitting device of claim 1 flirter comprising a substrate, wherein the layer of first conductivity type overlies the substrate, the light emitting layer overlies the layer of first conductivity type, and the layer of second conductivity type overlies the light emitting layer.