LIGHT-EMITTING DEVICE AND METHOD FOR PRODUCING THE SAME

• US 20110116252A1
• Filed: 11/09/2010
• Published: 05/19/2011
• Est. Priority Date: 11/13/2009
• Status: Active Grant

• Current Assignee: Heavy Duty Lighting LLC (Ni, Wang & Massand, PLLC)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: AGATANI, Makoto, Hata, Toshio, Uemura, Toyonori
• Granted Patent: US 9,024,334 B2
• Time in Patent Office: Days
• US Class Current: 362/84
• 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: H01L 2224/48091 Arched
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• 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 33/38 with a particular shape
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 Optical field-shaping 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: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/167 incorporating printed resistors
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: Y10T 29/49764 with testing or indicating

Abstract

The light-emitting device of the present invention includes LED chips provided on a ceramic substrate and a sealing material in which the LED chips are embedded. The sealing material contains a fluorescent substance and divided into a first fluorescent-substance-containing resin layer and a second fluorescent-substance-containing resin layer by a first resin ring and a second resin ring.

Claims

1. A light-emitting device comprising:

a plurality of light-emitting elements provided on a substrate; and

a sealing material in which the plurality of light-emitting elements are embedded, the sealing material containing a fluorescent substance and being divided into a plurality of areas by a partition wall.

2. The light-emitting device as set forth in claim 1, wherein:

the partition wall (i) is formed on the substrate in such a manner that the partition wall has a circular shape or a cyclic polygonal shape when the substrate is viewed from above and includes at least two partition walls which are formed concentrically.

3. The light-emitting device as set forth in claim 2, wherein:

the plurality of light-emitting elements are provided along a circle which is concentric with the partition wall.

4. The light-emitting device as set forth in claim 1, wherein:

the sealing material in each of the plurality of areas is different in at least one of fluorescent substance content and fluorescent substance composition.

5. The light-emitting device as set forth in claim 1, wherein:

the sealing material contains plural kinds of fluorescent substances.

6. The light-emitting device as set forth in claim 1, wherein:

the partition wall is colored with milky white or white.

7. The light-emitting device as set forth in claim 1, wherein:

the plurality of light-emitting elements are separated into a plurality of groups in which light-emitting elements in a same group are connected to each other via a patterned wire(s).

8. The light-emitting device as set forth in claim 1, further comprising:

at least one of a protective element and a printed resistor, between a main surface of the substrate and the partition wall.

9. The light-emitting device as set forth in claim 8, wherein:

the at least one of the protective element and the printed resistor is wholly covered with the partition wall.

11. The light-emitting device as set forth in claim 1, wherein:

the substrate is provided with a bridge electrode with which one of the plurality of light-emitting elements embedded in a first area is connected to another one of the plurality of light-emitting elements embedded in a second area, the first area and the second area being areas among the plurality of areas.

12. The light-emitting device as set forth in claim 11, wherein:

the bridge electrode is provided between the substrate and the partition wall and traverses the partition wall.

13. The light-emitting device as set forth in claim 11, wherein:

a part of the bridge electrode which part traverses the partition wall is thinner than the other part of the bridge electrode.

14. The light-emitting device as set forth in claim 11, wherein:

the plurality of light-emitting elements are connected in series via the bridge electrode.

15. The light-emitting device as set forth in claim 1, wherein:

the partition wall contains at least one of a thickener and a diffusing agent.

10. The light-emitting device as set forth in claim wherein:

the substrate is further provided with a first electrode land for external connection and a second electrode land for external connection which (i) are respectively provided on both end areas of the main surface of the substrate and (ii) are not covered with the sealing material.

16. A method for producing a light-emitting device, said method comprising the steps of:

(a) providing a plurality of light-emitting elements on a substrate;

(b) providing a partition wall on the substrate;

(c) providing a first sealing material containing a fluorescent substance in one of areas separated by the partition wall;

(d) measuring a chromatic characteristic of the light-emitting device in which the first sealing material has been provided;

(e) in accordance with a result of the measurement, providing a second sealing material containing a fluorescent substance in other one of the areas separated by the partition wall; and

(f) measuring the chromatic characteristic of the light-emitting device in which the second sealing material has been provided.

17. The method as set forth in claim 16, wherein:

the step (a) includes

(g) providing, before the step (d), some of the plurality of light-emitting elements in one of the areas separated by the partition wall, and

(h) providing, after the step (d), rest of the plurality of light-emitting elements in the other one of the areas in which the second sealing material is to be formed.

18. The method as set forth in claim 16 further comprising the step of:

(i) providing, before the step (d), a light-shielding plate in such a manner that the light-shielding plate covers the second sealing material.

19. The method as set forth in claim 16 comprising the steps of:

(j) providing, instead of the step (e), a pseudo fluorescent sheet so that the pseudo fluorescent sheet covers the other one of the areas in which the second sealing material is to be formed; and

(k) measuring a chromatic characteristic of the light-emitting device in which the pseudo fluorescent sheet has been provided.