LIGHT EMITTING DEVICE AND METHOD OF MANUFACTURING THE SAME

• US 20090021140A1
• Filed: 05/16/2008
• Published: 01/22/2009
• Est. Priority Date: 05/18/2007
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: TAKASU, Isao, AMEMIYA, Isao, ABE, Kazuhide, HIOKI, Tsuyoshi, NOMURA, Yuko
• Granted Patent: US 7,839,087 B2
• Time in Patent Office: Days
• US Class Current: 313/502
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• 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 2924/00014 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 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• 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 33/54 having a particular shape

Abstract

A method of manufacturing a light emitting device. The method includes: mounting a light emitting chip on a substrate; forming a transparent resin portion and a phosphor layer by using a liquid droplet discharging apparatus, the transparent resin portion being formed in a shape of a dome and covering the light emitting chip to fill an exterior thereof on the substrate, a phosphor layer containing phosphor and being formed on an exterior of the transparent resin portion close to at least a top side thereof; and forming a reflecting layer at a position exterior of the transparent resin portion and the phosphor layer close to the substrate.

Claims

1. A method of manufacturing a light emitting device, comprising:

mounting a light emitting chip on a substrate;

forming a transparent resin portion and a phosphor layer by using a liquid droplet discharging apparatus, the transparent resin portion being formed in a shape of a dome and covering the light emitting chip to fill an exterior thereof on the substrate, a phosphor layer containing phosphor and being formed on an exterior of the transparent resin portion close to at least a top side thereof; and

forming a reflecting layer at a position exterior of the transparent resin portion and the phosphor layer close to the substrate.

2. The method according to claim 1,

wherein the forming of the transparent resin portion and the phosphor layer includes discharging liquid droplets upward by the use of the liquid droplet discharging apparatus.

3. The method according to claim 2,

wherein the discharging of liquid droplets includes:

discharging liquid droplets of transparent resin upward onto the substrate and an outer side of the light emitting chip, and

then discharging liquid droplets of transparent resin containing the phosphor upwards.

4. The method according to claim 2,

wherein the discharging of liquid droplets includes:

discharging liquid droplets of transparent resin containing phosphor upward onto the substrate and an outer side of the light emitting chip, and

precipitating the phosphor in the transparent resin in a portion near a surface of the dome before the transparent resin is cured.

5. The method according to claim 1,

wherein the forming of the reflecting layer includes discharging droplets of metal-containing ink by the liquid droplet discharging apparatus.

6. The method according to claim 5,

wherein the metal-containing ink is discharged upward.

7. The method according to claim 1,

wherein the forming of the reflecting layer is performed in advance of the forming of the transparent resin portion and the phosphor layer.

8. The method according to claim 1,

wherein the forming of the reflecting layer is performed after the forming of the transparent resin portion and the phosphor layer.

9. The method according to claim 1,

wherein the liquid droplet discharging apparatus discharges liquid droplets by a sound pressure using a converged ultrasonic wave.

10. The method according to claim 1, further comprising:

subjecting a surface of the substrate on which the chip is mounted to a water repellency treatment in advance of the forming of the transparent resin portion and the phosphor layer.

11. A light emitting device comprising:

a substrate;

a light emitting chip mounted on the substrate;

a transparent resin portion being formed in a shape of dome and covering the light emitting chip mounted on the substrate;

a phosphor-containing phosphor layer formed at least on an exterior of the transparent resin portion close to a top side thereof; and

a reflecting layer formed at a position exterior of the dome-shaped transparent resin portion and the phosphor layer close to the substrate.

12. The device according to claim 11,

wherein the substrate has a flat surface being in contact at least with the light emitting chip, the transparent resin portion and the reflecting layer.

13. The device according to claim 11,

wherein the phosphor layer includes a plurality of phosphor particles dispersed in the transparent resin;

and

the phosphor particles are distributed to be larger in diameter as positions thereof get closer to a surface of the phosphor layer.

14. The device according to claim 11,

wherein the light emitting chip comprises a blue color LED chip;

the phosphor comprises a yellow color phosphor; and

the light emitting device emits white light.

15. The device according to claim 11, further comprising:

a second transparent resin portion covering an exterior of the phosphor layer;

a second phosphor layer containing a green color phosphor and being formed on an exterior of the second transparent resin portion close to at least a top side thereof;

a third transparent resin portion covering an exterior of the second phosphor layer;

a third phosphor layer containing a blue color phosphor and being formed on an exterior of the third transparent resin portion close to at least a top side thereof;

wherein the light emitting chip comprises an ultraviolet LED chip;

the phosphor comprises a red color phosphor; and

the light emitting device emits white light.