LIGHT EMITTING DEVICE, DISPLAY DEVICE AND MANUFACTURING METHOD OF THE LIGHT EMITTING DEVICE

• US 20100246213A1
• Filed: 09/17/2008
• Published: 09/30/2010
• Est. Priority Date: 09/21/2007
• Status: Abandoned Application

• Current Assignee: Showa Denko KK
• Original Assignee: Showa Denko KK
• Inventors: Naijo, Shuichi
• Application Number:
  US12/679,104
• Publication Number:
  US 20100246213A1
• Time in Patent Office: Days
• US Class Current: 362/613
• CPC Class Codes: G02B 6/003 Lens or lenticular sheet or layer
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02B 6/0083 Details of electrical connections of light sources to drivers, circuit boards, or the like
• CPC Class Codes: G02B 6/0085 Means for removing heat created by the light source from the package heat extraction or cooling elements for semiconductor light sources in general H01L33/64
• CPC Class Codes: G02F 1/133628 with cooling means
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/54 having a particular shape
• 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 3/202 using self-supporting metal foil pattern

Abstract

A light emitting module (40) includes: eight LEDs emitting red, green and blue light; electric conductor part (60) electrically connected to the LEDs and constitute power feeding routes for the LEDs; a heat conductor part (50) provided so as to be electrically insulated from the electric conductor parts (60) and constitute a heat dissipating route for heat produced by the LEDs; and a lens (70) which seals the LEDs while including respective parts of the electric conductor parts (60) and the heat conductor part (50). Bending process is applied to each of the electrodes, such as a red positive lead electrode portion (61a), of the electric conductor part (60) which are exposed from the lens (70) and a heat dissipating portion (52) etc. in the heat conductor part (50) which are exposed from the lens (70). Accordingly, temperature change in the light emitting elements and accompanying light intensity change are suppressed, and at the same time, thinning of the light emitting device including the light emitting elements is achieved.

Claims

1. A light emitting device comprising:

a plurality of light emitting elements;

an electric conductor that is electrically connected to each of the plurality of light emitting elements, and that forms a power feeding route for the plurality of light emitting elements;

a heat conductor that is disposed so as to be electrically insulated from the electric conductor, and that forms a heat dissipating route for heat produced by the plurality of light emitting elements; and

a sealing part that seals the plurality of light emitting elements while including a part of the electric conductor and a part of the heat conductor, wherein

respective portions, exposed from the sealing part, of the electric conductor and the heat conductor are bent.

2. The light emitting device according to claim 1, wherein

the sealing part has a passage surface through which light emitted from the plurality of light emitting elements passes, and

the heat conductor is bent toward the passage surface side of the sealing part.

3. The light emitting device according to claim 1, wherein the plurality of light emitting elements are arrayed in line.

4. The light emitting device according to claim 1, wherein

the plurality of light emitting elements includes a red light emitting element that emits red light, a green light emitting element that emits green light, and a blue light emitting element that emits blue light, and

the electric conductor has a red power feeding route for feeding electric power to the red light emitting element, a green power feeding route for feeding electric power to the green light emitting element, and a blue power feeding route for feeding electric power to the blue light emitting element.

5. The light emitting device according to claim 1, wherein

the electric conductor includes a plurality of electrodes that receive power feeding from an outside, and a connecting conductor that electrically connects each of the plurality of electrodes and the plurality of light emitting elements,

the heat conductor includes a holding part that holds the plurality of light emitting elements, and a transmission part that is connected to the holding part and that transmits heat produced by the plurality of light emitting elements through the holding part, and

respective parts of the electrodes are exposed from the sealing part in the electric conductor, and a part of the transmission part is exposed from the sealing part in the heat conductor.

6. The light emitting device according to claim 5, wherein

the plurality of electrodes forming the electric conductor are arranged side by side on one end portion side of the sealing part, and the transmission part forming the heat conductor is arranged on the other end portion side of the sealing part.

7. A display device comprising:

a display panel for displaying an image; and

a backlight that is disposed on a back side of the display panel and that illuminates, with light, the display panel from the back side thereof;

wherein

the backlight includes;

a light guide plate that emits light incident on a side surface thereof toward the display panel; and

a light source that illuminates, with light, the light guide plate from the side surface thereof, wherein

the light source includes;

a plurality of light emitting elements;

an electric conductor that is electrically connected to each of the plurality of light emitting elements, and that forms a power feeding route for the plurality of light emitting elements;

a heat conductor that is disposed so as to be electrically insulated from the electric conductor, and that forms a heat dissipating route for heat produced by the plurality of light emitting elements; and

a sealing part that seals the plurality of light emitting elements while including a part of the electric conductor and a part of the heat conductor, and

respective portions, exposed from the sealing part, of the electric conductor and the heat conductor are bent.

8. The display device according to claim 7, wherein a plurality of the light sources are attached so as to be arrayed side by side along the side surface of the light guide plate.

9. The display device according to claim 8, further comprising a wiring board that is arranged so as to stride the plurality of light sources, and electrically connected to the electric conductor disposed in each of the plurality of light sources.

10. The display device according to claim 7, wherein the heat conductor is bent in a direction closer to the light guide plate, and the electric conductor is bent in a direction away from the light guide plate.

11. The display device according to claim 7, wherein the sealing part has a passage surface through which light emitted from the plurality of light emitting elements passes, the passage surface being aspheric.

12. A manufacturing method of a light emitting device including a plurality of light emitting elements, an electric conductor that is electrically connected to each of the plurality of light emitting elements and forms a power feeding route for the plurality of light emitting elements, a heat conductor that is disposed so as to be electrically insulated from the electric conductor and forms a heat dissipating route for heat produced by the plurality of light emitting elements, and a sealing part that seals the plurality of light emitting elements, the manufacturing method comprising the steps of:

mounting the plurality of light emitting elements on a lead frame in which the electric conductor and the heat conductor are connected through a bridging part;

forming the sealing part to the lead frame having the plurality of light emitting elements mounted thereon, the sealing part sealing the plurality of light emitting elements while including a part of the electric conductor and a part of the heat conductor;

removing the bridging part from the lead frame having the sealing part formed thereto; and

bending respective portions, exposed to an outside, of the electric conductor and the heat conductor.

13. The manufacturing method of the light emitting device according to claim 12, wherein

the electric conductor of the lead frame includes a plurality of electrodes that receive power feeding from an outside, and a connecting conductor that electrically connects the plurality of electrodes and the plurality of light emitting elements,

the heat conductor of the lead frame includes a holding part that holds the plurality of light emitting elements, and a transmission part that is connected to the holding part and that transmits heat produced by the plurality of light emitting elements through the holding part, and

the step of forming includes exposing respective parts of the electrodes from the sealing part, and exposing a part of the transmission part from the sealing part.

14. The manufacturing method of the light emitting device according to claim 12, wherein, in the step of forming, the sealing part is not formed to the bridging part.

15. The manufacturing method of the light emitting device according to claim 12, wherein the step of forming includes forming, to the sealing part, a passage surface through which light emitted from the plurality of light emitting elements having been sealed passes.

16. The manufacturing method of the light emitting device according to claim 15, wherein the step of bending includes bending the heat conductor toward the passage surface side of the sealing part, and bending the electric conductor toward a side opposite to the passage surface side.