Method for producing a ceramic conversion element and light-emitting device

Patent metadata

Field	Value
Publication number	US-9831398-B2
Application number	US-201515111152-A
Country	US
Kind code	B2
Filing date	Jan 20, 2015
Priority date	Jan 23, 2014
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

A method for producing a ceramic conversion element and a light-emitting device are disclosed. In an embodiment the method includes providing at least four functional layers, each being a green body or a ceramic, wherein first functional layer is formed as a first luminous layer comprising an oxide and configured to at least partially convert light of a first wavelength range into light of a second wavelength range, wherein a second functional layer is formed as a second luminous layer comprising a nitride and configured to at least partially convert light of the first wavelength range into light of a third wavelength range, wherein a third functional layer is formed as a first intermediate layer, wherein the first intermediate layer comprises an oxide, wherein a fourth functional layer is formed as a second intermediate layer, and wherein the second intermediate layer comprises a nitride or an oxynitride.

First claim

The invention claimed is:

1. A method for producing a ceramic conversion element, the method comprising:
providing at least four functional layers, each being a green body or a ceramic,
wherein first functional layer is formed as a first luminous layer comprising an oxide and configured to at least partially convert light of a first wavelength range into light of a second wavelength range,
wherein a second functional layer is formed as a second luminous layer comprising a nitride and configured to at least partially convert light of the first wavelength range into light of a third wavelength range,
wherein a third functional layer is formed as a first intermediate layer, wherein the first intermediate layer comprises an oxide,
wherein a fourth functional layer is formed as a second intermediate layer, and wherein the second intermediate layer comprises a nitride or an oxynitride,
arranging the first to fourth functional layers such that the first intermediate layer lies between the first luminous layer and the second intermediate layer, and the second intermediate layer lies between the first intermediate layer and the second luminous layer; and
mechanically connecting the functional layers using at least one sintering process, wherein after the sintering process the first and the second luminous layers and the first and second intermediate layers are formed as a ceramic.

2. The method according to claim 1 , wherein the first luminous layer is in direct contact with the first intermediate layer and not in direct contact with the second intermediate layer and the second luminous layer, and wherein the second luminous layer is in direct contact with the second intermediate layer and not in direct contact with the first intermediate layer and the first luminous layer.

3. The method according to claim 2 , wherein the first intermediate layer is in direct contact with the second intermediate layer.

4. The method according to claim 1 , wherein the first luminous layer comprises a cerium-doped lutetium aluminum garnet, wherein the first intermediate layer comprises an undoped yttrium aluminum garnet, wherein the second intermediate layer comprises a silicon nitride, and wherein the second luminous layer comprises an Eu 2+ -doped alkaline earth silicon nitride.

5. The method according to claim 1 , wherein the first and/or second luminous layers comprises at least one activator, and wherein a concentration of the respective activator is between 0.1% and 6% and the respective activator is a rare earth element.

6. The method according to claim 1 , wherein the first intermediate layer protects the first luminous layer from chemical reactions and diffusion processes with the second luminous layer and the second intermediate layer during a sintering process, and wherein the second intermediate layer protects the second luminous layer from chemical reactions and diffusion processes with the first luminous layer and the first intermediate layer during a sintering process.

7. The method according to claim 1 , wherein the first and second intermediate layers are transparent to and non-absorbing for light of the first and/or second wavelength range.

8. The method according to claim 1 , wherein the first luminous layer and/or the first intermediate layer and/or the second intermediate layer are configured to be reflective for light of the third wavelength range.

9. The method according to claim 1 , wherein at least one of the first to fourth functional layers comprises scattering centers at which light of the first and/or second and/or third wavelength range is diffusely scatterable.

10. The method according to claim 1 , wherein each the first to fourth functional layers comprises two plan-parallel major sides.

11. The method according to claim 1 , wherein the first to fourth functional layers are arranged one over another in a direction away from a major side of a functional layer such that the major sides of the first to fourth functional layers all extend in parallel with each other.

12. The method according to claim 1 , wherein a thickness of the first luminous layer is between 30 μm and 150 μm, wherein a thickness of the second luminous layer is between 5 μm and 100 μm, and wherein a thicknesses of each of the first and second intermediate layers are between 0.2 μm and 10 μm.

13. The method according to claim 1 , wherein, after a separation process, a lateral extent of the first and second luminous layers and the first and second intermediate layers along associated major sides is between 5 μm and 5 mm.

14. The method according to claim 1 , wherein the at least first to fourth functional layers are arranged next to each other in a direction in parallel with major sides such that the major sides of the first to fourth functional layers extend in parallel with each other and wherein, as seen in plan view of the major sides, the at least first to fourth functional layers do not overlap.

15. The method according to claim 1 , wherein the ceramic conversion element is mechanically self-supporting.

16. The method according to claim 1 , wherein the first luminous layer is provided as a ceramic or as a green body, wherein the first intermediate layer is applied on the first luminous layer as a green body, wherein the second intermediate layer is applied, as a green body, on a side of the first intermediate layer facing away from the first luminous layer, wherein the second luminous layer is applied, as a green body, onto a side of the second intermediate layer facing away from the first luminous layer, and wherein the at least first to fourth functional layers are sintered in a common sintering process to form the ceramic conversion element.

17. The method according to claim 1 , wherein the first intermediate layer and/or the second intermediate layer is applied using one of the following deposition processes: pulsed laser deposition, atomic layer deposition, chemical vapor deposition or aerosol deposition.

18. The method according to claim 1 , wherein the first luminous layer and the first intermediate layer are sintered together to form a first ceramic composite, wherein the second luminous layer and the second intermediate layer are sintered together to form a second ceramic composite, and wherein first ceramic composite and the second ceramic composite are sintered together thereafter.

19. A light-emitting device comprising;
an electroluminescent body having a radiation exit surface which is configured to emit light of a first wavelength range during operation; and
a ceramic conversion element produced according to claim 1 , the ceramic conversion element being arranged in a beam path of the light of a first wavelength range, wherein the ceramic conversion element is configured to at least partially convert the light of the first wavelength range emitted by the electroluminescent body into light of a second and a third wavelength ranges such that the light-emitting device is configured to transmit mixed light having proportions of the first, second and third wavelength ranges.

20. A method for producing a ceramic conversion element, the method comprising:
providing at least four functional layers, each being in a green body or a ceramic,
wherein a first functional layer is formed as a first luminous layer comprising an oxide and configured to at least partially convert light of a first wavelength range into light of a second wavelength range,
wherein a second functional layer is formed as a second luminous layer comprising a nitride and co

Assignees

• Osram Opto Semiconductors Gmbh

Inventors

• Göötz Britta

Classifications

• C09K11/7774

  Aluminates · CPC title

• C04B2237/368

  Silicon nitride · CPC title

• C04B2237/08

  Non-oxidic interlayers · CPC title

• C09K11/7792

  Aluminates · CPC title

• C04B2237/72

  Forming laminates or joined articles comprising at least two interlayers directly next to each other · CPC title