Method of making phosphor containing glass plate, method of making light emitting device

• US 7,989,236 B2
• Filed: 12/22/2008
• Issued: 08/02/2011
• Est. Priority Date: 12/27/2007
• Status: Active Grant

• Current Assignee: Sumita Optical Glass, Inc., Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Sumita Optical Glass, Inc., Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Nonogawa, Takashi, Yamaguchi, Seiji, Suehiro, Yoshinobu, Watanabe, Hiroki, Aida, Kazuya
• Primary Examiner(s): Richards; N Drew
• Assistant Examiner(s): Lee; Kyoung
• Application Number:
  US12/318,150
• Publication Number:
  US 20090186433A1
• Time in Patent Office: 953 Days
• Field of Search: None
• US Class Current: 438/26
• CPC Class Codes: C03B 19/063 by hot-pressing powders
• CPC Class Codes: C03C 14/004 the non-glass component being in the form of particles or flakes
• CPC Class Codes: C03C 14/006 the non-glass component being in the form of microcrystallites, e.g. of optically or electrically active material
• CPC Class Codes: C03C 27/00 Joining pieces of glass to pieces of other inorganic material; Joining glass to glass other than by fusing C03C17/00 takes precedence; layered structures comprising at least one glass sheet B32B17/00; wired glass C03B; joining glass to ceramics C04
• CPC Class Codes: C03C 8/24 Fusion seal compositions being frit compositions having non-frit additions, i.e. for use as seals between dissimilar materials, e.g. glass and metal; Glass solders
• CPC Class Codes: C09K 11/7734 Aluminates
• CPC Class Codes: C09K 11/7741 Sulfates
• CPC Class Codes: H01L 2224/05023 the whole internal layer protruding from the surface
• CPC Class Codes: H01L 2224/0508 being stacked
• CPC Class Codes: H01L 2224/05124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/05568 the whole external layer protruding from the surface
• CPC Class Codes: H01L 2224/05573 Single external layer
• CPC Class Codes: H01L 2224/05644 Gold [Au] as principal constituent
• CPC Class Codes: H01L 2224/06102 the bonding areas being at different heights
• CPC Class Codes: H01L 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2224/1703 Bump connectors having different sizes, e.g. different diameters, heights or widths
• CPC Class Codes: H01L 24/97 the devices being connected to a common substrate, e.g. interposer, said common substrate being separable into individual assemblies after connecting
• 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 2924/12041 LED
• CPC Class Codes: H01L 2924/15787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2933/0041 : relating to wavelength conversion elements
• CPC Class Codes: H01L 33/501 : characterised by the materials, e.g. binder
• CPC Class Codes: Y02P 40/57 : Improving the yield, e-g- reduction of reject rates

Abstract

A method of making a light emitting device includes mixing a glass powder with a phosphor powder including at least one of a sulfide phosphor, an aluminate phosphor and a silicate phosphor to produce a mixed powder in which the phosphor powder is dispersed in the glass powder, heating and softening the mixed powder to provide an integrated material, and subsequently solidifying the integrated material to provide a phosphor-dispersed glass, and fusion-bonding the phosphor-dispersed glass onto a mounting portion on which a light emitting element is mounted by hot pressing, and simultaneously sealing the light emitting element with the phosphor-dispersed glass on the mounting portion.

Claims

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

mixing a glass powder with a phosphor powder including at least one of a sulfide phosphor, an aluminate phosphor and a silicate phosphor to produce a mixed powder in which the phosphor powder is dispersed in the glass powder;

heating and softening the mixed powder to provide an integrated material, and subsequently solidifying the integrated material to provide a phosphor-dispersed glass; and

fusion-bonding the phosphor-dispersed glass onto a mounting portion on which a light emitting element is mounted by hot pressing, and simultaneously sealing the light emitting element with the phosphor-dispersed glass on the mounting portion.

2. The method according to claim 1, wherein the mixed powder is heated to provide the integrated material while applying a pressure thereto.

3. The method according to claim 2, wherein the light emitting element includes a plurality of light emitting elements, and

the method further comprises dividing the plurality of light emitting elements sealed with the phosphor-dispersed glass on the mounting portion into a plurality of light emitting devices.

4. The method according to claim 3, further comprising:

forming a phosphor layer including a phosphor different from the phosphor powder on a surface of the phosphor-dispersed glass after sealing the light emitting elements or dividing the plurality of light emitting elements.

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

processing the phosphor-dispersed glass into a plate, wherein the plate phosphor-dispersed glass is fusion-bonded onto the mounting portion.

6. The method according to claim 1, wherein the glass powder is prepared by being classified by a wet classification and then dried.

7. The method according to claim 1, further comprising adding a light diffusing powder to the mixed powder during said mixing.

8. The method according to claim 1, wherein the phosphor powder is dispersed in the glass powder before said heating and softening.

9. The method according to claim 1, wherein a diameter of a glass particle in the glass powder is less than about 200μ

m.

10. The method according to claim 1, wherein the fusion-bonding comprises:

placing the phosphor-dispersed glass on an upper mold comprising a first heater;

placing the mounting portion on a lower mold comprising a second heater; and

pressing the upper mold and the lower mold together at a range of about 20 to 40 kgf/cm².

11. The method according to claim 1, wherein a ratio of a thermal expansion coefficient of the phosphor-dispersed glass to a thermal expansion coefficient of the mounting portion is about 0.85 or more.

12. The method according to claim 1, wherein the heating and softening is conducted at a temperature that is within about 200°

C. from a yielding point of the glass powder.

16. The method according to claim 7, wherein said diffusing powder comprises one of a zirconia, an alumina, and a silica.

13. A method of making a phosphor containing glass plate, comprising:

mixing a glass powder with a phosphor powder including at least one of a sulfide phosphor, an aluminate phosphor and a silicate phosphor to produce a mixed powder in which the phosphor powder is dispersed in the glass powder;

heating and softening the mixed powder to provide an integrated material, and subsequently solidifying the integrated material to provide a phosphor-dispersed glass; and

processing the phosphor-dispersed glass into a plate.

14. The method according to claim 13, wherein the mixed powder is heated to provide the integrated material while applying a pressure thereto.

15. The method according to claim 13, wherein the glass powder is prepared by being classified by a wet classification and then dried.

17. The method according to claim 13, wherein the heating and softening is conducted at a temperature that is within about 200°

C. from a yielding point of the glass powder.

18. The method according to claim 13, wherein a diameter of a glass particle in the glass powder is less than about 200 μ

m.