SEMICONDUCTOR LIGHT EMITTING DEVICE

• US 20010015443A1
• Filed: 05/26/1999
• Published: 08/23/2001
• Est. Priority Date: 05/27/1998
• Status: Abandoned Application

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: KOMOTO, SATOSHI
• Application Number:
  US09/320,379
• Publication Number:
  US 20010015443A1
• Time in Patent Office: Days
• US Class Current: 257/81
• 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 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• 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 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01025 Manganese [Mn]
• CPC Class Codes: H01L 2924/01039 Yttrium [Y]
• CPC Class Codes: H01L 2924/01063 Europium [Eu]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H01L 33/641 characterized by the materials
• CPC Class Codes: H01L 33/647 : the elements conducting electric current to or from the semiconductor body

Abstract

A semiconductor light emitting device includes a lead frame made of a material having a thermal conductivity not higher than 100 W/(m·K), and a gallium nitride compound semiconductor light emitting element mounted on the lead frame. Alternatively, the semiconductor light emitting device includes a lead frame, a gallium nitride compound semiconductor light emitting element mounted on the lead frame, wires connecting electrode terminals of the lead frame to the light emitting element, a first encapsulater provided around the light emitting element to cover it, and a second encapsulater provided around the first encapsulater to cover it. Each wire has a larger diameter at one end portion thereof connected to the light emitting element than that of its major part, and the first encapsulater is provided so that its surface extends across the end portions.

Claims

1. A semiconductor light emitting device comprising:

a lead frame; and

a gallium nitride compound semiconductor light emitting element mounted on said lead frame,

said lead frame being made of a material having a thermal conductivity not higher than 100 W/(mK).

2. The semiconductor light emitting device according to

claim 1

further comprising:

a first encapsulater provided around said light emitting element to cover it; and

a second encapsulater provided around said first encapsulater to cover it.

3. The semiconductor light emitting device according to

claim 2

wherein a coefficient of linear expansion of said first encapsulater lies between that of said second encapsulater and said that of said a gallium nitride compound semiconductor light emitting element.

4. The semiconductor light emitting device according to

claim 2

wherein said first encapsulater contains a fluorescent material to absorb light of a first wavelength emitted from said light emitting element and to emit light of a second wavelength different from said first wavelength.

5. The semiconductor light emitting device according to

claim 2

herein said first encapsulater is made of an inorganic adhesive.

6. The semiconductor light emitting device according to

claim 5

wherein said inorganic adhesive is made of any one selected from the group consisting of alkali metal silicate, phosphate, colloidal silica, silica sol, water glass, Si(OH)_n, SiO₂ and TiO₂.

7. The semiconductor light emitting device according to claim 2 wherein said second encapsulater is made of a material having a glass transition temperature not lower than 150°

C.

8. The semiconductor light emitting device according to

claim 7

wherein said second encapsulater is made of epoxy resin.

9. The semiconductor light emitting device according to

claim 1

wherein said lead frame is made of an iron-based material.

10. A semiconductor light emitting device comprising:

a lead frame having an electrode terminal;

a gallium nitride compound semiconductor light emitting element mounted on said lead frame;

a wire connecting said electrode terminal of said lead frame to said light emitting element;

a first encapsulater provided around the light emitting element to cover it; and

a second encapsulater provided around the first encapsulater to cover it,

said wire having a larger diameter at one end portion thereof connected to said light emitting element than the remainder part thereof, and

the boundary between the first encapsulater and the second encapsulater extending across said end portion.

11. The semiconductor light emitting device according to

claim 10

wherein said lead frame has a cup portion and said gallium nitride compound semiconductor light emitting element is mounted on the bottom surface of said cup portion.

12. The semiconductor light emitting device according to

claim 11

wherein said cup portion of said lead frame defines an inner wall surface which is roughly finished at least in a part thereof.

13. The semiconductor light emitting device according to

claim 10

wherein said end portion is a ball portion or a neck portion formed by a bonding of said wire to said light emitting element.

14. The semiconductor light emitting device according to

claim 10

wherein said first encapsulater contains a fluorescent material to absorb light of a first wavelength emitted from said light emitting element and to emit light of a second wavelength different from said first wavelength.

15. The semiconductor light emitting device according to

claim 10

wherein said first encapsulater is made of an inorganic adhesive.

16. The semiconductor light emitting device according to

claim 15

wherein said inorganic adhesive is made of any one selected from the group consisting of alkali metal silicate, phosphate, colloidal silica, silica sol, water glass, Si(OH)_n, SiO₂ and TiO₂.

17. The semiconductor light emitting device according to

claim 10

wherein said second encapsulater is made of a material having a glass transition temperature not lower than 150°

C.

18. The semiconductor light emitting device according to

claim 10

wherein said lead frame is made of a material having a thermal conductivity not higher than 100 W/(mK).

19. The semiconductor light emitting device according to

claim 18

wherein said lead frame is made of an iron-based material.

20. The semiconductor light emitting device according to

claim 19

wherein said lead frame has an outer lead portion applied with solder outer plating.