Semiconductor light emitting device, light emitting module and lighting apparatus

• US 20060180818A1
• Filed: 07/22/2004
• Published: 08/17/2006
• Est. Priority Date: 07/30/2003
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Nagai, Hideo, Mukai, Kenji
• Granted Patent: US 7,473,934 B2
• Time in Patent Office: Days
• US Class Current: 257/89
• CPC Class Codes: F21K 9/00 Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2105/12 characterised by the geometrical disposition of the light-generating elements, e.g. arranging light-generating elements in differing patterns or densities
• CPC Class Codes: F21Y 2113/13 comprising an assembly of point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48091 Arched
• 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 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• 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

Abstract

An LED array chip (2) includes blue LEDs (6) and red LEDs (8). The blue LEDs (6) are formed by epitaxial growth on an SiC substrate (4). Bonding pads (46 and 48) are formed on the SiC substrate (4) in a wafer fabrication process. The red LEDs (8) are separately manufactured from the blue LEDs (6), and flip-chip mounted on the bonding pads (46 and 48) formed on the SiC substrate.

Claims

1. A semiconductor light emitting device comprising:

a substrate;

a first light emitting member that is formed on the substrate in an epitaxial growth step of a wafer fabrication process;

an electrically conductive pattern that is formed on the substrate in a wiring step of the wafer fabrication process; and

a second light emitting member that is separately formed and then mounted on the electrically conductive pattern, the second light emitting member emitting light of a different color from the first light emitting member.

2. The semiconductor light emitting device of claim 1, wherein

the electrically conductive pattern includes a plurality of pads,

the first light emitting member includes a plurality of first light emitting elements, and

the second light emitting member includes a plurality of second light emitting elements that are mounted on the plurality of pads in a one-to-one correspondence.

3. The semiconductor light emitting device of claim 2, wherein

the plurality of first light emitting elements and the plurality of second light emitting elements are arranged in a matrix on the substrate, in such a manner that every light emitting element adjacent to a second light emitting element in row and column directions is a first light emitting element.

4. The semiconductor light emitting device of claim 3, wherein

each of the plurality of first light emitting elements is one of a red LED and a blue LED, and each of the plurality of second light emitting elements is a different one of the red LED and the blue LED, and

the semiconductor light emitting device further comprises:

a phosphor that covers a plurality of red LEDs and a plurality of blue LEDs, the phosphor converting blue light emitted by the plurality of blue LEDs into green-yellow light.

5. The semiconductor light emitting device of claim 4, wherein

the red light has a peak emission wavelength within a range of 615 nm and 635 nm,

the blue light has a peak emission wavelength within a range of 450 nm and 470 nm, and

the green-yellow light has a peak emission wavelength within a range of 540 nm and 560 nm.

6. The semiconductor light emitting device of claim 5, wherein

the red light has a peak emission wavelength within a range of 620 nm and 630 nm,

the blue light has a peak emission wavelength within a range of 455 nm and 465 nm, and

the green-yellow light has a peak emission wavelength within a range of 545 nm and 555 nm.

7. The semiconductor light emitting device of claim 4, wherein

the phosphor is a silicate phosphor (Ba, Sr)2SiO4:

Eu2+.

8. The semiconductor light emitting device of claim 4, wherein

the substrate is made of one of SiC and AlN materials.

9. The semiconductor light emitting device of claim 2, further comprising:

a wiring pattern that is formed on the substrate in the wiring step of the wafer fabrication process, the wiring pattern electrically connecting the plurality of first light emitting elements and the plurality of second light emitting elements together.

10. The semiconductor light emitting device of claim 9, wherein

the wiring pattern connects the plurality of first light emitting elements and the plurality of second light emitting elements in series.

11. The semiconductor light emitting device of claim 1, wherein

the first light emitting member emits blue light, and the second light emitting member emits red light, and

the semiconductor light emitting device further comprises:

a phosphor that covers the first light emitting member and the second light emitting member, the phosphor converting the blue light into green-yellow light.

12. The semiconductor light emitting device of claim 11, wherein

the phosphor is a silicate phosphor (Ba, Sr)2SiO4:

Eu2+.

13. The semiconductor light emitting device of claim 11, wherein

the red light has a peak emission wavelength within a range of 615 nm and 635 nm,

the blue light has a peak emission wavelength within a range of 450 nm and 470 nm, and

the green-yellow light has a peak emission wavelength within a range of 540 nm and 560 nm.

14. The semiconductor light emitting device of claim 13, wherein

the red light has a peak emission wavelength within a range of 620 nm and 630 nm,

the blue light has a peak emission wavelength within a range of 455 nm and 465 nm, and

the green-yellow light has a peak emission wavelength within a range of 545 nm and 555 nm.

15. The semiconductor light emitting device of claim 1, further comprising

a third light emitting member that is mounted on the substrate, the third light emitting member emitting light of a different color from the first light emitting member and the second light emitting member.

16. A light emitting module comprising:

a printed-wiring board; and

a semiconductor light emitting device that is claimed in claim 1 and is mounted on the printed-wiring board.

17. A lighting apparatus comprising a light emitting module claimed in claim 16.