Wavelength-converting casting composition and its use

• US 6,066,861 A
• Filed: 05/20/1998
• Issued: 05/23/2000
• Est. Priority Date: 09/20/1996
• Status: Expired due to Term

• Current Assignee: OSRAM GmbH (Ams-Osram AG)
• Original Assignee: Siemens AG
• Inventors: Schlotter, Peter, Schmidt, Ralf, Schneider, Jurgen, Debray, Alexandra, Hohn, Klaus
• Primary Examiner(s): Tran, Minh Loan
• Application Number:
  US09/082,205
• Time in Patent Office: 734 Days
• Field of Search: 257/81, 257/89, 257/98, 257/99, 257/100, 313/486, 313/467, 313/468, 252/301.6 P, 252/301.4 R
• US Class Current: 257/99
• 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 A₃ B₅ X₁₂ :M, and the luminous substance pigments have particle sizes<20 μm and a mean grain diameter d₅₀ <5 μm.

Claims

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

a transparent epoxy casting resin;

an inorganic luminous substance pigment powder dispersed in said transparent epoxy resin, said pigment powder comprising luminous substance pigments from a phosphorus group having the general formula A₃ B₅ X₁₂ ;

M, where A is an element selected from the group consisting of Y, Ca, Sr;

B is an element selected from the group consisting of Al, Ga, Si;

X is an element selected from the group consisting of O and S;

M is an element selected from the group consisting of Ce and Tb;

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 particles of Ce-doped garnets.

7. The casting composition according to claim 6, wherein said luminous substance pigments are YAG:

Ce 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 substance pigments are formed with a silicon coating.

10. 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 at least one of an ultraviolet, blue, and green spectral range;

a wavelength-converting casting composition disposed in a vicinity of said semiconductor body, said casting composition being formed of a transparent epoxy casting resin and an inorganic luminous substance pigment powder dispersed in said transparent epoxy resin, said pigment powder comprising luminous substance pigments from a phosphorus group having the general formula A₃ B₅ X₁₂ ;

M, where A is an element selected from the group consisting of Y, Ca, Sr;

B is an element selected from the group consisting of Al, Ga, Si;

X is an element selected from the group consisting of O and S;

M is an element selected from the group consisting of Ce and Tb, and having grain sizes≦

20 μ

m and a mean grain diameter d₅₀ ≦

5 μ

m;

said luminous substance pigments converting a portion of the radiation originating from the ultraviolet, blue and green spectral range into radiation of a higher wavelength, such that the semiconductor component emits mixed radiation including the higher-wavelength radiation and radiation from at least one of the ultraviolet, blue and green spectral range.

11. The light-emitting semiconductor component according to claim 10, wherein said casting composition encloses at least a part of said semiconductor body.

12. The light-emitting semiconductor component according to claim 10, 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.

13. The light-emitting semiconductor component according to claim 10, 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.

14. The light-emitting semiconductor component according to claim 10, wherein said casting composition is provided with various kinds of luminous substance pigments in respect to a host lattice distribution and a type and extent of doping.