Light-emitting apparatus and method of producing the same

• US 7,687,823 B2
• Filed: 12/21/2007
• Issued: 03/30/2010
• Est. Priority Date: 12/26/2006
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Okada, Satoshi, Amo, Takahiro, Nishijima, Shinji, Hodono, Yoshifumi
• Primary Examiner(s): Smith; Zandra
• Assistant Examiner(s): Joy; Jeremy J
• Application Number:
  US11/963,250
• Publication Number:
  US 20080149960A1
• Time in Patent Office: 830 Days
• Field of Search: 257E33056-E33061, 257 98-100, 438/27, 438121-122, 438/124, 438/127
• US Class Current: 257/99
• CPC Class Codes: H01L 2224/32188 the layer connector connecting to a bonding area protruding from the surface of the item
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• 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 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/642 characterized by the shape

Abstract

A light-emitting apparatus includes a package including a support having a central section and a peripheral section around the central section. The central section is raised upwardly from the peripheral section, providing a pedestal for supporting a light-emitting device. A light-emitting device secured on an upper surface of the pedestal and has electrodes. Electrically conductive members are provided on a peripheral region of the package and electrically connected to the electrodes of the light-emitting device. A color conversion layer covers the light-emitting device. A light-transmitting member is formed in the package, sealing at least the light-emitting device together with the color conversion layer. The pedestal has its side surface at least partially exposed from the color conversion layer.

Claims

1. A light-emitting apparatus comprising:

a package comprising (a) a support having a central section and a peripheral section around the central section, the central section being raised upwardly from the peripheral section, providing a pedestal for supporting a light-emitting device, and (b) an insulating substrate having a central through-hole therein, an inner wall of the substrate that defines the central through-hole having an annular ledge protruding from a lower portion of the inner wall of the substrate with a side surface of the ledge being spaced apart from a peripheral surface of the pedestal, forming a recess, wherein the support is disposed in the central through-hole of the substrate such that an uppermost surface of the support is positioned higher than an upper surface of the ledge;

a light-emitting device secured on the uppermost surface of the pedestal and having electrodes;

electrically conductive members provided on a peripheral region of the package and electrically connected to the electrodes of the light-emitting device;

a color conversion layer covering the light-emitting device, the uppermost surface of the support and the upper surface of the ledge; and

a light-transmitting member formed in the package, sealing at least the light-emitting device together with the color conversion layer;

wherein the pedestal has its side surface at least partially exposed from the color conversion layer, and the color conversion layer is separated at the recess.

2. The light-emitting apparatus according to claim 1, wherein the color conversion layer is deposited substantially uniformly on the light-emitting device and on the peripheral section.

3. The light-emitting apparatus according to claim 1, wherein the color conversion layer comprises a portion of phosphor material which has been contained in the light-transmitting member and settled onto the light-emitting device.

4. The light-emitting apparatus according to claim 1, wherein

the light-emitting device is secured by a die-bonding member,

the die-bonding member covers a covering region extending from a lower edge of a side surface of the light-emitting device upwardly on a side surface of the device up to a position immediately below a position where a light-emitting layer of the light-emitting device is exposed, and

the color conversion layer covers a side surface of the device above the covering region, and also a side surface of the light-emitting layer.

5. The light-emitting apparatus according to claim 1, wherein a central region of the upper surface of the pedestal is recessed, the light-emitting device is placed in the recess in the pedestal, and the color conversion layer is deposited thicker on the side surface of the light-emitting device than on the upper surface of the light-emitting device.

6. The light-emitting apparatus according to claim 5, wherein the recess in the pedestal has a depth such that a light-emitting layer of the light-emitting device is positioned higher than the upper surface of the pedestal.

7. The light-emitting apparatus according to claim 1, wherein the color conversion layer is locally formed on the upper surface of the pedestal.

8. The light-emitting apparatus according to claim 1, wherein the support is made of a metallic material.

9. The light-emitting apparatus according to claim 1, wherein the color conversion layer comprises a mixture of a phosphor material effecting the color conversion and a light-diffusing additive.

10. The light-emitting apparatus according to claim 1, wherein the color conversion layer comprises a phosphor material and a light-diffusing additive having substantially the same particle size and specific gravity, which have been contained in the light-transmitting member and have been settled down.

11. A method of producing a light-emitting apparatus according to claim 1, the method comprising depositing a phosphor material which has been contained in the light-transmitting member by settling down the phosphor material onto the pedestal, forming the color conversion layer, such that the color conversion layer is discontinued at a step between the upper surface of the pedestal and the upper surface of the peripheral section, thereby exposing a portion of the side surface of the pedestal exposed from the color conversion layer.

12. The light-emitting apparatus according to claim 1, wherein the color conversion layer is formed also in the recess formed between the side surface of the ledge and the peripheral surface of the pedestal.

13. A light-emitting apparatus comprising:

a package comprising an insulating substrate including a central through-hole therein, an inner wall of the substrate that defines the central through-hole having an annular ledge protruding therefrom, and a support including a central projection and a peripheral section around the central section, the support being disposed in the through-hole such that a side surface of the ledge is spaced apart from a peripheral surface of the central projection, forming a recess, and an upper surface of the support is positioned higher than an upper surface of the ledge;

a light-emitting device on the upper surface of the central projection and including electrodes;

electrically conductive members provided on a peripheral region of the package and electrically connected to the electrodes of the light-emitting device;

a color conversion layer on the light-emitting device, the upper surface of the support and the upper surface of the ledge; and

a light-transmitting member on at least the light-emitting device and the color conversion layer,

wherein a side surface of the central projection is at least partially exposed from the color conversion layer, and the color conversion layer is separated at the recess.

14. The light-emitting apparatus according to claim 13, further comprising:

a recess formed in the upper surface of the central projection, wherein the light-emitting device is disposed in the recess.

15. The light-emitting apparatus according to claim 13, wherein the insulating substrate comprises multiple laminated substrate layers.

16. The light-emitting apparatus according to claim 13, wherein the support comprises a metallic material.

17. The light-emitting apparatus according to claim 13, further comprising:

a die bonding member securing the light-emitting device to the central projection.

18. The light-emitting apparatus according to claim 13, wherein the light-emitting member comprises a light-diffusing additive.

19. The light-emitting apparatus according to claim 13, wherein the color conversion layer comprises a light-diffusing additive.