SEMICONDUCTOR LIGHT EMITTING DEVICE AND MANUFACTURING METHOD

• US 20120236582A1
• Filed: 01/23/2012
• Published: 09/20/2012
• Est. Priority Date: 01/24/2011
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: ITO, Kosaburo, SEKO, Toshihiro, WARAGAYA, Takeshi, UENO, Kazuhiko, OWADA, Soji
• Granted Patent: US 8,581,287 B2
• Time in Patent Office: Days
• US Class Current: 362/510
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• 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 33/502 Wavelength conversion materials
• 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 33/60 Reflective elements

Abstract

A semiconductor light-emitting device and a method for manufacturing the same can include a wavelength converting layer in order to emit various colored lights including white light. The device can include a board, a frame located on the board, at least one light-emitting chip mounted on the board, the wavelength converting layer located between an optical plate and an outside surface of the chips so that a density of a peripheral region is lower than that of a middle region, and a reflective material layer disposed at least between the frame and a side surface of the wavelength-converting layer. The device can have the reflective material layer form each reflector and can use a wavelength converting layer having different densities, and therefore can emit a wavelength-converted light having a high light-emitting efficiency and a uniform color tone from various small light-emitting surfaces.

Claims

1. A semiconductor light-emitting device comprising:

a base board having a mounting surface and a conductor pattern located on the mounting surface;

a semiconductor light-emitting chip having a bottom surface, a top surface and an outside surface, and including chip electrodes adjacent the bottom surface, the chip electrodes being electrically connected to a respective portion of the conductor pattern of the base board via solder bumps;

an optical plate having a side surface, a bottom surface, a middle region, a peripheral region and an edge located between the side surface and the bottom surface, the peripheral region surrounding the middle region and including the edge of the optical plate, the optical plate being located over the top surface of the semiconductor light-emitting chip so that the middle region of the optical plate overlaps the top surface of the semiconductor light-emitting chip;

a wavelength converting layer having a side surface and a thickness, the wavelength converting layer including at least one phosphor and disposed between the edge of the optical plate and the outside surface of the semiconductor light-emitting chip so that the side surface of the wavelength converting layer extends from the outside surface of the semiconductor light-emitting chip toward the edge of the optical plate, wherein a density of the at least one phosphor included in the wavelength converting layer that is disposed between the middle region of the optical plate and the top surface of the semiconductor light-emitting chip is higher than that of the phosphor included in the wavelength converting layer that is disposed between the peripheral region of the optical plate and the outside surface of the semiconductor light-emitting chip;

a frame located adjacent the mounting surface of the base board so as to surround the semiconductor light-emitting chip and the wavelength converting layer; and

a reflective material layer having an inclined side surface disposed between the frame and both the side surface of the wavelength converting layer and the side surface of the optical plate and between the bottom surface of the semiconductor light-emitting chip and the mounting surface of the base board while also surrounding the solder bumps, wherein the inclined side surface contacts with the side surface of the wavelength converting layer and extends from the outside surface of the semiconductor light-emitting chip toward the edge of the optical plate.

2. The semiconductor light-emitting device according to claim 1, wherein the wavelength converting layer includes an upper layer and a lower layer that are divided by an imaginary central plane between the bottom surface of the optical plate and the top surface of the semiconductor light-emitting chip, and a density of the phosphor included in the wavelength converting layer of the lower layer located on the top surface of the semiconductor light-emitting chip is higher than a density of the phosphor included in the wavelength converting layer of the upper layer.

3. The semiconductor light-emitting device according to claim 1, wherein the bottom surface of the peripheral region of the optical plate is formed as a rough surface, and the bottom surface of the middle region of the optical plate is formed as at least one of a rough surface and a plane surface, wherein a roughness on the bottom surface of the peripheral region is larger than a roughness of the middle region.

4. The semiconductor light-emitting device according to claim 1, wherein the inclined side surface of the reflective material layer is formed in at least one of a substantially linear shape and a convex shape having a curvature of 5 or less extending in a direction toward the semiconductor light-emitting chip between the side surface of the semiconductor light-emitting chip and the edge of the optical plate.

5. The semiconductor light-emitting device according to claim 1, further comprising:

an outer meniscus control structure projecting from the bottom surface of the optical plate toward the semiconductor light-emitting chip and extending along the edge of the optical plate, wherein the side surfaces of the wavelength converting layer extend from the outside surface of the semiconductor light-emitting chip to the outer meniscus control structure.

6. The semiconductor light-emitting device according to claim 1, further comprising:

a particulate spacer disposed in the wavelength converting layer, wherein the thickness of the wavelength converting layer is defined between the top surface of the semiconductor light-emitting chip and the bottom surface of the optical plate by supporting the bottom surface of the optical plate using the particulate spacer located on the top surface of the semiconductor light-emitting chip.

7. The semiconductor light-emitting device according to claim 1, further comprising a plurality of semiconductor light-emitting chips electrically connected to a respective portion of the conductor pattern of the base board.

16. A method for manufacturing the semiconductor light-emitting device according to claim 1, comprising:

providing the base board;

connecting each of the chip electrodes of the semiconductor light-emitting chip to a respective portion of the conductor pattern of the base board via the solder bumps;

disposing an uncured wavelength converting material between the bottom surface of the optical plate and the outside surface of the semiconductor light-emitting chip so as to extend from the outside surface of the semiconductor light-emitting chip toward the edge of the optical plate; and

disposing an uncured reflective material at least between the frame and both the side surface of the wavelength converting layer and the side surface of the optical plate and between the bottom surface of the semiconductor light-emitting chip and the mounting surface of the base board.

17. A method for manufacturing the semiconductor light-emitting device according to claim 3, comprising:

providing the base board;

connecting each of the chip electrodes of the semiconductor light-emitting chip to a respective portion of the conductor pattern of the base board via the solder bumps;

disposing an uncured wavelength converting material between the bottom surface of the optical plate and the outside surface of the semiconductor light-emitting chip so as to extend from the outside surface of the semiconductor light-emitting chip toward the edge of the optical plate; and

disposing an uncured reflective material at least between the frame and both the side surface of the wavelength converting layer and the side surface of the optical plate and between the bottom surface of the semiconductor light-emitting chip and the mounting surface of the base board.

8. A semiconductor light-emitting device comprising:

a base board having a mounting surface and a conductor pattern formed on the mounting surface;

a plurality of semiconductor light-emitting chips having an outside surface and at least one pair of adjacent surfaces, and each of the semiconductor light-emitting chips having a bottom surface and a top surface, being formed in a substantially cubic shape and including chip electrodes adjacent the bottom surface, the chip electrodes electrically connected to a respective portion of the conductor pattern of the base board via solder bumps, and the plurality of semiconductor light-emitting chips aligned so that each of the at least one pair of adjacent surfaces is substantially parallel with respect to each other;

an optical plate having a side surface, a bottom surface, a middle region, a peripheral region and an edge located between the side surface and the bottom surface, the peripheral region surrounding the middle region and including the edge of the optical plate, the optical plate being located over the top surface of each of the semiconductor light-emitting chips so that the middle region of the optical plate overlaps the top surface of each of the semiconductor light-emitting chips;

a wavelength converting layer having a thickness, at least one side surface and at least one concave surface, the wavelength converting layer including at least one phosphor and disposed between the outside surface of the semiconductor light-emitting chips and the edge of the optical plate so that the side surface of the wavelength converting layer extends from the outside surface of the semiconductor light-emitting chips toward the edge of the optical plate, and the concave surface of the wavelength converting layer being located between the at least one pair of adjacent surfaces and formed in a concave shape toward the peripheral region of the optical plate, wherein a density of the at least one phosphor included in the wavelength converting layer that is disposed between the middle region of the optical plate and the top surface of each of the semiconductor light-emitting chips is higher than a density of the phosphor included in the wavelength converting layer that is disposed between the peripheral region of the optical plate and both the outside surface of the semiconductor light-emitting chip and the at least one concave surface of the wavelength converting layer;

a frame located adjacent the mounting surface of the base board so as to surround the wavelength converting layer and the semiconductor light-emitting chips; and

a reflective material layer having an inclined side surface and at least one convex surface disposed between the frame and both the side surface of the wavelength converting layer and the side surface of the optical plate and between the bottom surface of each of the semiconductor light-emitting chips and the mounting surface of the base board while surrounding the solder bumps, wherein the inclined side surface contacts with the side surface of the wavelength converting layer and extends from the outside surface of the semiconductor light-emitting chips toward the edge of the optical plate, and the at least one convex surface also contacts with the at least one concave surface of the wavelength converting layer and extends toward the peripheral region of the optical plate between the at least one pair of adjacent surfaces of the plurality of semiconductor light-emitting chips.

9. The semiconductor light-emitting device according to claim 8, wherein the wavelength converting layer includes an upper layer and a lower layer that are divided by an imaginary central plane between the bottom surface of the optical plate and the top surface of each of the semiconductor light-emitting chips, and a density of the phosphor included in the wavelength converting layer of the lower layer located on the top surface of each of the light-emitting chips is higher than a density of the phosphor included in the wavelength converting layer of the upper layer.

10. The semiconductor light-emitting device according to claim 8, wherein the bottom surface of the peripheral region of the optical plate is formed as a rough surface, and the bottom surface of the middle region of the optical plate is formed as at least one of a rough surface and a plane surface, wherein a roughness on the bottom surface of the peripheral region is larger than a roughness of the middle region.

11. The semiconductor light-emitting device according to claim 8, wherein the inclined side surface of the reflective material layer is formed in at least one of a substantially linear shape and a convex shape having a curvature of 5 or less extending in a direction toward the semiconductor light-emitting chips between the side surface of each of the semiconductor light-emitting chips and the edge of the optical plate.

12. The semiconductor light-emitting device according to claim 8, further comprising:

an outer meniscus control structure projecting from the bottom surface of the optical plate toward the semiconductor light-emitting chips and extending along the edge of the optical plate, wherein the side surface of the wavelength converting layer extends from the outside surface of the semiconductor light-emitting chips to the outer meniscus control structure.

13. The semiconductor light-emitting device according to claim 8, further comprising:

a particulate spacer disposed in the wavelength converting layer, wherein the thickness of the wavelength converting layer is defined between the top surface of each of the semiconductor light-emitting chips and the bottom surface of the optical plate by supporting the bottom surface of the optical plate using the particulate spacer located on the top surface of each of the semiconductor light-emitting chips.

14. A vehicle headlight including the semiconductor light-emitting device according to claim 8, and further comprising:

a heat sink connected with the semiconductor light-emitting device; and

a reflector having an opening portion located adjacent the heat sink so that light emitted from the semiconductor light-emitting device during operation of the semiconductor light-emitting device is emitted in a light-emitting direction of the vehicle headlight from the opening portion of the reflector.

15. A vehicle headlight including the semiconductor light-emitting device according to claim 9, and further comprising:

a heat sink connected with the semiconductor light-emitting device; and

a reflector having an opening portion located adjacent the heat sink so that light emitted from the semiconductor light-emitting device during operation of the semiconductor light-emitting device is emitted in a light-emitting direction of the vehicle headlight from the opening portion of the reflector.

18. A method for manufacturing the semiconductor light-emitting device according to claim 8, comprising:

providing the base board;

connecting each of the chip electrodes of the semiconductor light-emitting chips to a respective portion of the conductor pattern of the base board via the solder bumps;

disposing an uncured wavelength converting material between the bottom surface of the optical plate and the outside surface of the semiconductor light-emitting chips so as to extend from the outside surface of the semiconductor light-emitting chips toward the edge of the optical plate; and

disposing an uncured reflective material at least between the frame and both the side surface of the wavelength converting layer and the side surface of the optical plate and between both the bottom surface of each of the semiconductor light-emitting chips and the at least one concave surface of the wavelength converting layer and the mounting surface of the base board.

19. The method for manufacturing the semiconductor light-emitting device according to claim 18, further comprising:

precipitating the at least one phosphor included in the uncured wavelength converting material toward the top surface of each of the semiconductor light-emitting chips, during disposing the uncured wavelength converting material between the bottom surface of the optical plate and the outside surface of the semiconductor light-emitting chips so as to extend from the outside surface of the semiconductor light-emitting chips toward the edge of the optical plate.

20. A method for manufacturing the semiconductor light-emitting device according to claim 10, comprising:

providing the base board;

connecting each of the chip electrodes of the semiconductor light-emitting chips to a respective portion of the conductor pattern of the base board via the solder bumps;

disposing an uncured wavelength converting material between the bottom surface of the optical plate and the outside surface of the semiconductor light-emitting chips so as to extend from the outside surface of the semiconductor light-emitting chips toward the edge of the optical plate; and

disposing an uncured reflective material at least between the frame and both the side surface of the wavelength converting layer and the side surface of the optical plate and between both the bottom surface of each of the semiconductor light-emitting chips and the at least one concave surface of the wavelength converting layer and the mounting surface of the base board.