LIGHT EMITTING DEVICE AND METHOD FOR MANUFACTURING THE SAME

• US 20080224608A1
• Filed: 03/17/2008
• Published: 09/18/2008
• Est. Priority Date: 03/15/2007
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: KONISHI, Masahiro, Hata, Toshio, Agatani, Makoto
• Granted Patent: US 7,843,131 B2
• Time in Patent Office: Days
• US Class Current: 313/505
• CPC Class Codes: F21K 9/20 Light sources comprising attachment means
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21V 23/002 Arrangements of cables or conductors inside a lighting device, e.g. means for guiding along parts of the housing or in a pivoting arm
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/45169 Platinum (Pt) as principal constituent
• 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 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/01015 Phosphorus [P]
• CPC Class Codes: H01L 2924/01047 Silver [Ag]
• CPC Class Codes: H01L 2924/01068 Erbium [Er]
• CPC Class Codes: H01L 2924/01087 : Francium [Fr]
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 33/32 : containing nitrogen
• CPC Class Codes: H01L 33/36 : characterised by the electrodes
• CPC Class Codes: H01L 33/38 : with a particular shape
• 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: H01L 33/60 : Reflective elements
• 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

Abstract

By using a light emitting device including an insulating substrate and a light emitting unit formed on the insulating substrate, the light emitting unit including: a plurality of linear wiring patterns disposed on the insulating substrate in parallel with one another, a plurality of light emitting elements that are mounted between the wiring patterns while being electrically connected to the wiring patterns, and a sealing member for sealing the light emitting elements, as well as a method for manufacturing thereof, it becomes possible to provide a light emitting device that achieves sufficient electrical insulation and has simple manufacturing processes so that it can be manufactured at a low cost, and a method for manufacturing the same.

Claims

1. A light emitting device comprising:

an insulating substrate; and

a light emitting unit formed on the insulating substrate, wherein

the light emitting unit includes;

a plurality of linear wiring patterns disposed on the insulating substrate in parallel with one another;

a plurality of light emitting elements mounted between the wiring patterns while being electrically connected to the wiring patterns; and

a sealing member for sealing the light emitting elements.

2. The light emitting device according to claim 1, wherein the plurality of light emitting elements are mounted with each of the linear wiring patterns being sandwiched therebetween, to be linearly aligned along the wiring patterns.

3. The light emitting device according to claim 2, wherein the light emitting elements mounted with each of the linear wiring patterns being sandwiched therebetween are disposed to be mutually shifted such that side faces thereof do not oppose one another.

4. The light emitting device according to claim 1, wherein the light emitting elements, each having a rectangular shape in cross section, are mounted such that a direction along a short side thereof is parallel with a longitudinal direction of the wiring patterns.

5. The light emitting device according to claim 4, wherein each of the light emitting elements has an elongated shape in cross section.

6. The light emitting device according to claim 1, wherein the light emitting elements mounted with each of the linear wiring patterns being sandwiched therebetween are electrically connected in series with one another.

7. The light emitting device according to claim 2, wherein the light emitting elements linearly mounted along the linear wiring patterns are electrically connected in parallel with one another.

8. The light emitting device according to claim 1, wherein the wiring patterns further include one of a pattern used for positioning electrical connections between the light emitting elements and a pattern serving as a measure for mounting positions of the light emitting elements.

9. The light emitting device according to claim 1, wherein a linear distance between each light emitting element and each wiring pattern is 0.1 mm or more.

10. The light emitting device according to claim 1, wherein the insulating substrate is a white ceramic substrate.

11. The light emitting device according to claim 10, wherein the white ceramic substrate is made of at least one material selected from aluminum oxide, aluminum nitride, boron nitride, silicon nitride, magnesium oxide, forsterite, steatite, and low-temperature sintered ceramics, or a composite material of these materials.

12. The light emitting device according to claim 1, wherein all the linear wiring patterns and light emitting elements on the insulating substrate are sealed by a single sealing member.

13. The light emitting device according to claim 1, wherein the sealing member contains a fluorescent material.

14. The light emitting device according to claim 13, wherein the sealing member includes a first sealing member layer containing a first fluorescent material and a second sealing member layer that contains a second fluorescent material and is laminated on the first sealing member layer.

15. The light emitting device according to claim 14, wherein the second sealing member layer is laminated on the first sealing member layer in such a manner as to cover at least one portion of the first sealing member layer.

16. The light emitting device according to claim 1, wherein the sealing member is formed into a shape having one of a hexagonal shape, a round shape, a rectangular shape, and a square shape in cross section.

17. The light emitting device according to claim 1, the device having a shape having one of a round shape and a square shape in cross section.

18. The light emitting device according to claim 1, the device being used for one of a backlight light source of a liquid crystal display and a light source for illumination.

19. A method for manufacturing a light emitting device comprising the steps of

forming wiring patterns on an insulating substrate;

mounting a light emitting element between the wiring patterns;

electrically connecting the light emitting element and the wiring patterns;

placing a silicone rubber sheet having a through hole onto the insulating substrate; and

forming a sealing member for sealing the light emitting element in the through hole of the silicone rubber sheet.

20. The method according to claim 19 for manufacturing a light emitting device, further comprising the steps of:

inspecting a characteristic of the light emitting element after electrical connection between the light emitting element and the wiring patterns is made; and

upon detection of any defect in the characteristic as a result of the inspection, connecting a spare light emitting element with the wiring patterns.

21. The method according to claim 19 for manufacturing a light emitting device,

wherein the sealing member contains a fluorescent material.

22. The method according to claim 21 for manufacturing a light emitting device,

wherein the step of sealing the light emitting element by using the sealing member includes the steps of:

injecting a sealing material containing a first fluorescent material into the through hole of the silicone rubber sheet;

curing the sealing material containing the first fluorescent material to form a first sealing member layer; and

measuring a chromaticity characteristic of the light emitting device after the first sealing member layer is formed.

23. The method according to claim 22 for manufacturing a light emitting device, further comprising the steps of:

after the step of measuring a chromaticity characteristic of the light emitting device after the first sealing member layer is formed, injecting a sealing material containing a second fluorescent material onto the first sealing member layer;

curing the sealing material containing the second fluorescent material to form a second sealing member layer;

measuring a chromaticity characteristic of the light emitting device after the second sealing member layer is formed; and

removing the silicone rubber sheet.