Wavelength-converting casting composition and white light-emitting semiconductor component

• US 6,613,247 B1
• Filed: 09/01/2000
• Issued: 09/02/2003
• Est. Priority Date: 09/20/1996
• Status: Expired due to Term

• Current Assignee: OSRAM GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Schlotter, Peter, Schmidt, Ralf, Schneider, Jürgen, Höhn, Klaus, Debray, Alexandra
• Primary Examiner(s): Koslow, C. Melissa
• Application Number:
  US09/654,368
• Time in Patent Office: 1,096 Days
• Field of Search: 252/301.36, 252/301.4 R, 257/99, 257/98, 257/100, 313/486, 313/467, 313/468
• US Class Current: 252/301.36
• CPC Class Codes: C09K 11/7774 Aluminates
• 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 2224/48472 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 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 2924/00014 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 33/502 Wavelength conversion materials
• 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 garnets, thiogallates, aluminates, or orthosilicates doped with rare earths, and preferably Ce-doped phosphors. The luminous substance pigments have particle sizes ≦20 μm and a mean grain diameter d₅₀≦5 μM.

Claims

1. A wavelength-converting casting composition, comprising:

a transparent epoxy casting resin;

an inorganic luminous substance pigment powder dispersed in said transparent casting resin, said pigment powder comprising 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

said luminous substance pigments having grain sizes ≦

20 μ

m and a mean grain diameter d₅₀ ≦

5 μ

m.

2. The casting composition according to claim 1, wherein said luminous substance pigments are substantially spherical particles.

3. The casting composition according to claim 1, wherein said luminous substance pigments are flakelike particles.

4. The casting composition according to claim 1, wherein the mean grain diameter d₅₀ of said luminous substance pigments is between one and two micrometers.

5. The casting composition according to claim 1, which comprises the following components:

a) epoxy casting resin ≧

60% by weight;

b) luminous substance pigments >

0 and ≦

25% by weight;

c) thixotropic agent >

0 and ≦

10% by weight;

d) mineral diffusor >

0 and ≦

10% by weight;

e) processing adjuvant >

0 and ≦

3% by weight;

f) hydrophobic agent >

0 and ≦

3% by weight; and

g) adhesion promoters >

0 and ≦

2% by weight.

6. The casting composition according to claim 1, wherein said luminous substance pigments are Ce-doped garnets.

7. The casting composition according to claim 1, wherein said luminous substance pigments are YAG:

Ce based particles.

8. The casting composition according to claim 1, which comprises a content of iron ≦

20 ppm.

9. The casting composition according to claim 1, wherein said luminous pigment are formed with a silicone coating.

10. The casting composition according to claim 1, wherein said luminous substances pigment powder converts a wavelenght of ultraviolet, blue, or green light into a relatively longer wavelenght.

11. The casting composition according to claim 1, which comprises light-scattering particles added to said casting resin.

12. A light emitting semiconductor component, comprising;

a semiconductor body formed of a semiconductor layer sequence and being capable, during an operation of the semiconductor component, of emitting electromagnetic radiation in a first spectral range selected from ultraviolet, blue, and green;

wavelength-converting casting composition disposed in a vicinity of said semiconductor body and formed of a transparent epoxy casting resin in an inorganic luminous substance pigment powder dispersed in said transparent casting resin;

said pigment powder comprising luminous substance pigments selected from the group consisting of garnets dopes with rare earths;

thiogallates doped with rare earths;

aluminates doped with rare earths; and

orthosilicates doped with rare earths; and

said luminous substance pigments having grain sizes ≦

20 μ

m and a mean grain diameter d₅₀≦

5 μ

m and converting a portion of the radiation originating from said semiconductor component into radiation of a higher wavelength, such that the semiconductor component emits mixed radiation including the higher-wavelength radiation and radiation from the first spectral range.

13. The light-emitting semiconductor component according to claim 12, wherein said casting composition encloses at least a part of said semiconductor body.

14. The light-emitting semiconductor component according to claim 12, wherein said semiconductor body is adapted to emit radiation in a blue spectral range having a maximum luminescence intensity at λ

=430 nm or at λ

=450 nm.

15. The light-emitting semiconductor component according to claim 12, which further comprises an opaque base housing having a recess formed therein, said semiconductor body being disposed in said recess and said recess being at least partially filled with said casting composition.

16. The light-emitting semiconductor component according to claim 12, wherein said pigment powder comprises of at least two luminous substance pigments, where at least one is selected from the luminous substances group of claim 12.

17. The light-emitting semiconductor component according to claim 12, wherein said semiconductor body is a blue light emitting semiconductor body, and said luminous substance pigments are Ce-doped phosphors adapted to shift some of the blue light emitted by said semiconductor body into a yellow spectral range, whereby the semiconductor component emits white light.

18. The light-emitting semiconductor component according to claim 12, wherein said semiconductor body is a blue light emitting semiconductor body, and said luminous substance pigments shift some of the blue light emitted by said semiconductor body into a green and red spectral range, whereby the semiconductor component emits white light.

19. The light-emitting semiconductor component according to claim 12, wherein the mean grain diameter d₅₀ of said luminous substance pigments is between one and two micrometers.

20. The light-emitting semiconductor component according to claim 12, which comprises light-scattering particles added to said casting resin.

21. The light-emitting semiconductor according to claim 12, wherein said luminous substances pigment powder is a tempered pigment powder.