Light-emitting diode and method for the production thereof
View Patent ↗A light-emitting diode ( 1 ) has a lens body ( 3 ) that is fabricated from an inorganic solid. Fastened on the lens body ( 3 ) are semiconductor chips ( 2 ) that emit light beams ( 18 ). Furthermore, the light-emitting diode ( 1 ) is provided with a housing ( 20 ) that can be screwed into a conventional lamp holder via a thread ( 21 ).
1. A light-emitting diode comprising a semiconductor chip ( 2 ) that has a photon-emitting active layer ( 5 ) applied on a substrate ( 4 ), and, seen from the substrate ( 4 ), a contact layer ( 8 ) subsequent to the active layer ( 5 ), wherein there is arranged on the contact layer ( 8 ) a lens body ( 3 ) that is made from a radiation-resistant solid, is transparent to the emitted photons, and dissipates the heat from the active layer ( 5 ); and
wherein a heat sink ( 13 , 24 ) is fitted on the lens body ( 3 ).
2. The light-emitting diode as claimed in claim 1 , wherein the lens body ( 3 ) is provided with a conductor track ( 12 ) that makes contact with contact layer ( 8 ).
3. The light-emitting diode as claimed in claim 1 , wherein the lens body ( 3 ) has the shape of a spherical segment.
4. The light-emitting diode as claimed in claim 1 , wherein the lens body ( 3 ) has an antireflection layer ( 15 ) on a luminous surface ( 11 ).
5. The light-emitting diode as claimed in claim 1 , wherein a layer ( 15 ) on a luminous surface ( 11 ) of the lens body ( 3 ) contains optical conversion materials.
6. The light-emitting diode as claimed in claim 1 , wherein the semiconductor chip ( 2 ) is mounted in a depression ( 14 ) in the lens body ( 3 ).
7. The light-emitting diode as claimed in claim 6 , wherein regions ( 6 ) of the active layer ( 5 ) that emit in a lateral direction are situated inside the depression ( 14 ) in such a way that photons ( 17 b ) emerging from the laterally emitting regions ( 6 ) of the active layer ( 5 ) are coupled into the lens body ( 3 ).
8. The light-emitting diode as claimed in claim 1 , wherein a rear side, facing the semiconductor chip ( 2 ), of the lens body ( 3 ) is at least partially reflective coated.
9. The light-emitting diode as claimed in claim 1 , wherein the lens body ( 3 ) is fabricated from SiC, Al 2 O 3 or a garnet crystal.
10. The light-emitting diode as claimed in claim 1 , wherein the active layer ( 5 ) is fabricated on the basis of Ga x Al y In 1−x−y N in which case it holds that 0≦x≦1, 0≦y≦1 and x+y≦1.
11. The light-emitting diode as claimed in claim 10 , wherein the substrate is an electrically conducting substrate which acts as one of the electric connections of the active layer ( 5 ).
12. The light-emitting diode as claimed in claim 11 , wherein the substrate is a doped SiC substrate.
13. The light-emitting diode as claimed in claim 1 , wherein a plurality of semiconductor chips ( 2 ) are mounted next to one another on the lens body ( 3 ).
14. The light-emitting diode as claimed in claim 13 , wherein all the semiconductor chips ( 2 a, 2 b ) are arranged in depressions ( 14 ).
15. The light-emitting diode as claimed in claim 1 , wherein the light-emitting diode is provided with a housing ( 20 ) that is equipped with a thread ( 21 ) for screwing into a lamp holder.
16. The light-emitting diode as claimed in claim 1 , wherein the light-emitting diode is provided on the rear side of the lens body ( 3 ) with a surface-mountable housing that can be mounted on the surface of an electric connecting plate.
17. The light-emitting diode as claimed in claim 1 , wherein the semiconductor chip ( 2 ) emits, inter alia, radiation from the ultraviolet spectral region.
18. The light-emitting diode as claimed in claim 1 , wherein the semiconductor chip ( 2 ) has a reflecting layer ( 7 ) on the side averted from the lens body ( 3 ).
19. The light-emitting diode as claimed in claim 1 , wherein the semiconductor chip ( 2 ) emits, inter alia, radiation from the blue or short wave green spectral region.
20. The light-emitting diode as claimed in claim 1 , wherein the spacing of the active layer ( 5 ) from the lens body ( 3 ) is small by comparison with the thickness of the substrate ( 4 ).
21. A method for producing a light-emitting diode as claimed in claim 1 , in which the semiconductor chip ( 2 ) is connected to the lens body ( 3 ) by means of laser soldering through the lens body ( 3 ), in particular via a conductor track ( 12 ) located on the lens body ( 3 ).
22. The method as claimed in claim 21 , having the following method steps:
(a) fabricating a plurality of lens bodies ( 3 ) in a wafer composite;
(b) applying conductor tracks ( 12 ) for a plurality of semiconductor chips ( 2 ) to the side of the wafer composite on which the semiconductor chips are later mounted;
(c) fastening a plurality of semiconductor chips on the conductor tracks ( 12 ) by means of laser soldering through the wafer composite; and
(d) dividing the wafer composite into smaller lens body units or into individual lens bodies ( 3 ) with semiconductor chips ( 2 ).
23. The method as claimed in claim 22 , in which between the steps (c) and (d) electric conductor tracks ( 22 ) for the electric connection of rear contacts ( 7 ) of the semiconductor chips ( 2 ) are applied to the wafer composite.