Wavelength-converting casting composition and light-emitting semiconductor component

• US 7,709,852 B2
• Filed: 05/21/2007
• Issued: 05/04/2010
• Est. Priority Date: 09/20/1996
• Status: Expired due to Fees

• Current Assignee: OSRAM GmbH (Ams-Osram AG)
• Original Assignee: OSRAM GmbH (Ams-Osram AG)
• Inventors: Schmidt, Ralf, Schlotter, Peter, Schneider, Jürgen, Höhn, Klaus, Debray, Alexandra
• Primary Examiner(s): TRAN, MINH LOAN
• Application Number:
  US11/751,291
• Publication Number:
  US 20070216281A1
• Time in Patent Office: 1,079 Days
• Field of Search: 257/98, 257/99, 257/100, 257/E33.059, 257/E33.061, 257/E33.074, 313/485, 313/486, 313/501, 313/502, 313/503, 313/504, 252/301.36, 252/301.4 R, 252/301.4 P, 252/301.6 P
• US Class Current: 257/98
• CPC Class Codes: C09K 11/7718 with alkaline earth metals
• CPC Class Codes: C09K 11/7746 with alkaline earth metals
• CPC Class Codes: C09K 11/7767 Chalcogenides
• CPC Class Codes: C09K 11/7769 Oxides C09K11/7768 takes precedence
• CPC Class Codes: C09K 11/7774 Aluminates
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/502 : Wavelength conversion materials
• CPC Class Codes: H01L 33/56 : Materials, e.g. epoxy or silicone resin
• CPC Class Codes: Y02B 20/00 : Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

The wavelength-converting casting composition is based on a transparent epoxy casting resin with a luminous substance admixed. The composition is used in an electroluminescent component having a body that emits ultraviolet, blue or green light. An inorganic luminous substance pigment powder with luminous substance pigments is dispersed in the transparent epoxy casting resin. The luminous substance is a powder of Ce-doped phosphors and the luminous substance pigments have particle sizes ≦20 μm and a mean grain diameter d₅₀≦5 μm.

Claims

1. Apparatus comprising:

a semiconductor body configured to emit electromagnetic radiation in a first wavelength range; and

a wavelength-converting casting composition positioned to receive the electromagnetic radiation from the semiconductor body and configured to convert some of the electromagnetic radiation from the first wavelength range to a second wavelength range,

wherein the casting composition comprises luminous substance pigments selected from the group consisting of garnets doped with rare earths;

thiogallates doped with rare earths;

aluminates doped with rare earths; and

orthosilicates doped with rare earths, and

wherein the luminous substance pigments having grain sizes ≦

20 μ

m and a median diameter ≦

5 μ

m, wherein 50% of the pigments have a grain diameter greater than said median diameter and 50% of the pigments have a grain diameter less than said median diameter.

2. The apparatus of claim 1, wherein the median diameter of the luminous substance pigments is between 1 and 2 micrometers.

3. The apparatus of claim 1, wherein the luminous substance pigments comprise Ce-doped garnet material.

4. The apparatus of claim 1, wherein the luminous substance pigments comprise YAG:

Ce material.

5. The apparatus of claim 1, wherein iron content in the casting composition is ≦

20 ppm.

6. The apparatus of claim 1, wherein the casting composition comprises epoxy resin and where the luminous substance pigments are dispersed within the epoxy resin.

7. The apparatus of claim 1, wherein the luminous substance pigments are configured to convert the electromagnetic radiation from a ultraviolet, blue or green spectral range to a relatively longer wavelength.

8. The apparatus of claim 1, wherein the casting composition further comprises light-scattering particles.

9. The apparatus of claim 1, wherein the first spectral range emitted by the semiconductor body comprises a maximum at a wavelength between 420 nm and 460 nm.

10. The apparatus of claim 1, wherein the first spectral range comprises ultraviolet, blue, or green.

11. The apparatus of claim 1, wherein during operating the electromagnetic radiation remaining in the first spectral range mixes with the converted electromagnetic radiation in the second spectral range to produce a mixed color electromagnetic radiation output for the apparatus.

12. The apparatus of claim 11, wherein the mixed color electromagnetic radiation output appears as white light.

13. The apparatus of claim 12, wherein the first spectral range comprises blue and the second spectral range comprises yellow, which mix to produce the appearance of the white light.

14. The apparatus of claim 12, wherein the first spectral range comprises blue and the second spectral range comprises green and red, all of which mix to produce the appearance of the white light.

15. The apparatus of claim 1, wherein the casting composition is spaced from the semiconductor body.

16. The apparatus of claim 1, wherein the casting composition is applied to the semiconductor body.

17. The apparatus of claim 16, wherein the casting composition is applied directly to the semiconductor body as a layer.

18. The apparatus of claim 1, further comprising a housing with a recess, and wherein the semiconductor body is positioned within the housing.

19. The apparatus of claim 16, wherein the casting composition covers the semiconductor body in the recess.