Method of producing a wavelength-converting casting composition

• US 6,277,301 B1
• Filed: 03/28/2000
• Issued: 08/21/2001
• 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, CAROL M
• Application Number:
  US09/536,564
• Time in Patent Office: 511 Days
• Field of Search: 252/301.36, 252/301.4 R
• US Class Current: 252/301.36
• 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 phosphorous group of the general formula A₃B₅X₁₂:M, and the luminous substance pigments have particle sizes ≦20 μm and a mean grain diameter d₅₀≦5 μm.

Claims

1. A method of producing a wavelength-converting casting composition, for converting a wavelength of ultraviolet, blue or green light emitted by an electroluminescent component, the method comprising:

providing a base of transparent epoxy casting resin;

providing a luminous substance pigment powder containing luminous substance pigments having grain sizes ≦

20 μ

m and a mean grain diameter d₅₀≦

5 μ

m and being selected from the group consisting of Ce-doped phosphors;

garnets doped with rare earths;

thiogallates doped with rare earths;

aluminates doped with rare earths; and

orthosilicates doped with rare earths;

tempering the luminous substance pigment powder at a temperature of ≧

200°

C. and subsequently mixing the tempered pigment powder with the epoxy casting resin.

2. The method according to claim 1, wherein the step of providing a luminous substance pigment powder comprises providing an inorganic luminous substance pigment powder comprising luminous substance pigments of agents doped with rare earths and having grain sizes ≦

20 μ

m and a mean grain diameter d₅₀≦

5 μ

m.

3. The method according to claim 1, which comprises, prior to the mixing step, slurrying the luminous substance pigment powder in a higher-boiling alcohol and subsequently drying the luminous substance pigment powder.

4. The method according to claim 1, which comprises, prior to the mixing step, adding a hydrophobic silicone wax to the luminous substance pigment powder.

5. The method according to claim 1, which comprises surface-modifying the luminous substance pigment powder at elevated temperatures with alcohols, glycol ethers and silicones.

6. A method of producing a wavelength-converting casting composition, the method comprising:

providing a base of transparent epoxy casting resin;

providing a luminous substance pigment powder containing luminous substance pigments having grain sizes ≦

20 μ

m and a mean grain diameter d₅₀≦

5 μ

m and being selected from the group consisting of Ce-doped phosphors;

garnets doped with rare earths;

thiogallates doped with rare earths;

aluminates doped with rare earths; and

orthosilicates doped with rare earths; and

mixing the pigment powder with the epoxy casting resin.

7. The method according to claim 6, which comprises, prior to the mixing step, tempering the luminous substance pigment powder at a temperature of ≧

200°

C.

8. The method according to claim 6, which comprises, prior to the mixing step, slurrying the luminous substance pigment powder in a high-boiling point alcohol and subsequently drying the luminous substance pigment powder.

9. The method according to claim 7, which comprises, prior to the mixing step, adding a hydrophobic silicone wax to the luminous substance pigment powder.

10. The method according to claim 7, which comprises surface-modifying the luminous substance pigment powder at elevated temperatures with alcohols, glycol ethers and silicones.

11. A method of producing a wavelength-converting casting composition for a white light emitting semiconductor component having an electroluminescing semiconductor body emitting blue light, the method comprising:

providing a base of transparent epoxy casting resin;

providing a luminous substance pigment powder of luminous substance pigments having grain sized ≦

20 μ

m and a mean grain diameter d₅₀≦

5 μ

m, the pigment powder comprising luminous substance pigments from Ce-doped phosphors which shift some of the blue light emitted by the semiconductor body into the yellow spectral range; and

mixing the pigment powder with epoxy casting resin.

12. The method according to claim 11, wherein the pigment powder comprises luminous pigments from a phosphorous group having the general formula A₃B₅O₁₂:

M, where A is at least one element selected from the group consisting of Y, Gd and Lu;

B is at least one element selected from the group consisting of Al and Ga; and

M is at least one element selected from the group consisting of Ce, Eu and Cr.

13. The method according to claim 12, wherein the mean grain diameter d₅₀ of the luminous substance pigments is between one and two micrometers.

14. The method according to claim 12, which comprises adding light-scattering particles to the casting composition.

15. The method according to claim 11, which comprises, prior to the mixing step, tempering the luminous substance pigment powder at a temperature of ≧

200°

C.

16. A method of producing a wavelength-converting casting composition for a white light emitting semiconductor component having an electroluminescing semiconductor body emitting blue light, the method comprising:

providing a base of transparent epoxy casting resin;

providing a luminous substance pigment powder of luminous substance pigments having grain sizes ≦

20 μ

m and a mean grain diameter d₅₀≦

5 μ

m;

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

thiogallates doped with rare earths;

alluminates doped with rare earths; and

orthosilicates doped with rare earths;

which pigments shift some of the blue light emitted by the semiconductor body into the green and red spectral range; and

mixing the tempered pigment powder with the epoxy casting resin.

17. The method according to claim 16, wherein the main grain diameter d₅₀ of the luminous substance pigments is between one and two micrometers.

18. The method according to claim 16, which comprises adding light-scattering particles to the casting composition.

19. The method according to claim 16, which comprises, prior to the mixing step, tempering the luminous substance pigment powder at a temperature of ≧

200°

C.