Light emitting device

• US 9,966,367 B2
• Filed: 05/05/2017
• Issued: 05/08/2018
• Est. Priority Date: 01/22/2010
• 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: Ishizaki, Shinya, Agatani, Makoto, Nada, Tomokazu, Hata, Toshio
• Primary Examiner(s): Tran, Minh-Loan
• Application Number:
  US15/587,759
• Publication Number:
  US 20170243859A1
• Time in Patent Office: 368 Days
• Field of Search: None
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: F21K 9/238 Arrangement or mounting of circuit elements integrated in the light source
• CPC Class Codes: F21V 29/74 with fins or blades
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21V 5/048 the lens being a simple lens adapted to cooperate with a point-like source for emitting mainly in one direction and having an axis coincident with the main light transmission direction, e.g. convergent or divergent lenses, plano-concave or plano-convex lenses
• CPC Class Codes: F21V 5/10 comprising photoluminescent material
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/167 comprising optoelectronic devices, e.g. LED, photodiodes
• CPC Class Codes: H01L 27/15 including semiconductor components having potential barriers, specially adapted for light emission
• 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 2924/3011 Impedance
• CPC Class Codes: H01L 33/38 with a particular shape
• CPC Class Codes: H01L 33/483 Containers
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body
• CPC Class Codes: H01L 33/52 Encapsulations
• 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 33/60 : 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

Abstract

A light emitting device includes: a ceramic substrate; a plurality of LED chips; a printed resistor(s) connected in parallel with the plurality of LED chips; a dam resin made of a resin having a low optical transmittance; a fluorescent-material-containing resin layer; and an anode-side electrode and a cathode-side electrode, (a) which are provided on a primary surface of the ceramic substrate so as to face each other along a first direction on the primary surface and (b) which are disposed below at least one of the dam resin and the fluorescent-material-containing resin layer. With the configuration in which a plurality of LEDs, which are connected in a series-parallel connection, are provided on a substrate, it is possible to provide a light emitting device which can achieve restraining of luminance unevenness and an improvement in luminous efficiency.

Claims

1. A light emitting device comprising:

a substrate;

a plurality of LED chips positioned around a center of a primary surface of the substrate;

a resin frame made of resin that has light reflectivity, formed on the primary surface of said substrate and provided annularly so as to surround a mounting area in which said plurality of LED chips are provided;

an anode-side electrode land and a cathode-side electrode land which are electrodes to be connected to an external voltage supply of said light emitting device, the anode-side electrode land and the cathode-side electrode land being provided outside said resin frame;

an electrode wiring pattern formed on the primary surface of said substrate including (i) an anode pattern extending from said anode-side electrode land to a portion under said resin frame and

(ii) a cathode pattern extending from said cathode-side electrode land to another portion under said resin frame, so as to electrically connect the plurality of LED chips to the anode-side electrode land and the cathode-side electrode land; and

a protection film provided on the anode pattern and the cathode pattern.

2. The light emitting device as set forth in claim 1, wherein said substrate has rectangular outer shape in a top view.

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

the cathode-side electrode land is provided near a corner of the primary surface of the substrate, which corner is diagonally opposite a corner where the anode-side electrode land is provided.

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

the anode-side electrode land and the cathode-side electrode land are disposed diagonally on the primary surface of the substrate.

5. The light emitting device as set forth in claim 1, wherein the anode-side electrode land and the cathode-side electrode land are provided near corners of the primary surface of the substrate.

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

a fluorescent-material-containing resin layer provided so as to (i) be attached to an inner side of the resin frame and (ii) cover the plurality of LED chips.

7. The light emitting device as set forth in claim 6 wherein:

the fluorescent-material-containing resin layer is provided along a shape of the resin frame so as to have a circular shape in the top view.

8. The light emitting device as set forth in claim 1, wherein each of said anode-side electrode land and said cathode-side electrode land has a width larger than that of said electrode wiring pattern.

9. The light emitting device as set forth in claim 1, wherein said substrate comprises ceramic.

10. The light emitting device as set forth in claim 1, wherein said LED chips are attached to the primary surface of said substrate via a resin adhesive agent comprising silicone.

11. The light emitting device as set forth in claim 1, wherein said anode pattern further extends to the mounting area.

12. The light emitting device as set forth in claim 1, wherein said cathode pattern further extends to the mounting area.

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

the protection film includes a first protection film and a second protection film; and

the first protection film and the second protection film are provided on the anode pattern and the cathode pattern, respectively.

14. The light emitting device as set forth in claim 13, wherein at least part of the first protection film and at least part of the second protection film are provided so as to be exposed without being covered with the resin frame.