Semiconductor light emitting device
A semiconductor light-emitting device has an emitter matrix with an arrangement of emitter cells interspersed with non-emitter cells. The emitter cell has a semiconductor emitter, and a non-emitter cell does not have a semiconductor emitter. A number of bond pads for connection to a power supply and a plurality of wirebonds are present. Each wirebond extends from a bond pad to the semiconductor emitter of an emitter cell. An imaging arrangement includes a light source for illuminating a scene. The light source has a pair of such semiconductor light-emitting devices. A method of manufacturing such a semiconductor light-emitting device is also described.
1. A light-emitting device, comprising:
an emitter matrix comprising an arrangement of emitter cells and non-emitter cells in an array having at least one of a plurality of emitter cells and a plurality of non-emitter cells in at least one row and at least one column of the array such that at least each set of at least one of the emitter cells in one of the at least one row and one of the at least one column is adjacent to at least one of the non-emitter cells, each emitter cell containing a semiconductor emitter configured to emit light, and each non-emitter cell not configured to emit light;
circuitry configured to individually control light emission from each of the semiconductor emitters in the emitter cells;
wirebonds physically coupled to each emitter cell to provide current to the semiconductor emitters of the emitter cells to provide current to the semiconductor emitters in the emitter cells to control the light emission from the semiconductor emitters in the emitter cells;
bond pads adjacent to the emitter matrix, the wirebonds extending between the bond pads and the emitter cells, no wirebonds extending between the bond pads and the non-emitter cells; and
each non-emitter cell containing at least one element selected from elements including:
a semiconductor emitter, and
a switching element but does not contain a semiconductor emitter.
2. The light-emitting device of claim 1 , wherein each non-emitter cell contains a semiconductor emitter.
3. The light-emitting device of claim 1 , wherein each non-emitter cell contains a switching element but does not contain a semiconductor emitter.
4. The light-emitting device of claim 1 , wherein:
each emitter cell comprises a discrete die,
each non-emitter cell comprises a discrete switching element,
the discrete dies are mounted on a carrier, and
each die is wirebonded to a switching element in a neighboring non-emitter cell.
5. The light-emitting device of claim 4 , wherein the carrier comprises a printed circuit board (PCB), the PCB comprising a body that contains conductive tracks embedded therein to the circuitry.
6. The light-emitting device of claim 5 , wherein:
each emitter die is electrically coupled to the conductive tracks via an underside contact and a topside contact to which one of the wirebonds is physically connected, and
the circuitry comprises a driver electrically coupled to each emitter die through at least one of the underside contact and topside contact.
7. The light-emitting device of claim 1 , wherein:
each emitter cell is adjacent to at least one non-emitter cell,
each non-emitter cell is adjacent to at least one emitter cell, and
each wirebond extends from one of the emitter cells to an adjacent non-emitter cell to couple the one of the emitter cells to the adjacent non-emitter cell.
8. The light-emitting device of claim 7 , wherein each non-emitter cell comprises a switching element configured to control current to an adjacent emitter cell.
9. The light-emitting device of claim 1 , wherein the emitter cells and non-emitter cells have identical sizes and do not overlap.
10. The light-emitting device of claim 1 , wherein the emitter cells and non-emitter cells are arranged in a checkerboard pattern of alternating emitter cells and non-emitter cells.
11. The light-emitting device of claim 1 , wherein the emitter cells and non-emitter cells are arranged in a pattern of multiple emitter cells separated by at least one non-emitter cell.
12. The light-emitting device of claim 1 , wherein the light-emitting device is disposed in a smart phone.
13. The light-emitting device of claim 1 , wherein the switching elements comprise transistors.
14. A camera comprising:
a light source comprising a pair of semiconductor light-emitting devices, each semiconductor light-emitting device configured to illuminate a scene and comprising:
an emitter matrix comprising an arrangement of emitter cells and non-emitter cells in an array having at least one of a plurality of emitter cells and a plurality of non-emitter cells in at least one row and at least one column of the array such that at least each set of at least one of the emitter cells in one of the at least one row and one of the at least one column is adjacent to at least one of the non-emitter cells, each emitter cell containing a semiconductor emitter configured to emit light, and each non-emitter cell not configured to emit light;
switching elements, each switching element coupled to a different one of the semiconductor emitters; and
wirebonds physically coupled to each emitter cell to provide current to the semiconductor emitters of the emitter cells;
a driver configured to individually drive each semiconductor emitter via the switching element; and
an image sensor arrangement for capturing an image of the scene illuminated by the light source, the emitter matrices of the semiconductor light-emitting devices being complementary.
15. The camera of claim 14 , further comprising beam-forming optics configured to shape the light emitted by each of the emitter matrices to cover the scene.
16. The camera of claim 14 , wherein the camera is disposed in a smartphone.
17. A light-emitting device, comprising:
an emitter matrix comprising an arrangement of emitter cells and non-emitter cells in an array having at least one of a plurality of emitter cells and a plurality of non-emitter cells in at least one row and at least one column of the array such that at least each set of at least one of the emitter cells in one of the at least one row and one of the at least one column is adjacent to at least one of the non-emitter cells, each emitter cell containing a semiconductor emitter configured to emit light, and each non-emitter cell not configured to emit light;
circuitry configured to individually control light emission from each of the semiconductor emitters in the emitter cells; and
wirebonds physically coupled to each emitter cell to provide current to the semiconductor emitters of the emitter cells to provide current to the semiconductor emitters in the emitter cells to control the light emission from the semiconductor emitters in the emitter cells,
further comprising at least one element selected from elements of:
each non-emitter cell comprises a semiconductor emitter but no wirebond is physically coupled to an adjacent non-emitter cell, and
each emitter cell comprises a discrete die, each non-emitter cell comprises a discrete switching element, the discrete dies are mounted on a carrier, and each discrete die is wirebonded to a switching element in a neighboring non-emitter cell.