PROCESS FOR PRODUCING LIGHT-EMITTING DEVICE AND LIGHT-EMITTING DEVICE

• US 20090072265A1
• Filed: 11/18/2008
• Published: 03/19/2009
• Est. Priority Date: 05/18/2006
• Status: Abandoned Application

• Current Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Original Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Inventors: Nakamura, Nobuhiro, Matsumoto, Syuji
• Application Number:
  US12/273,194
• Publication Number:
  US 20090072265A1
• Time in Patent Office: Days
• US Class Current: 257/100
• CPC Class Codes: C03C 3/155 containing zirconium, titanium, tantalum or niobium
• CPC Class Codes: C03C 3/253 containing germanium
• 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 2224/13 of an individual bump connector
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 24/05 of an individual bonding area
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/56 Materials, e.g. epoxy or silicone resin
• CPC Class Codes: H01L 33/58 Optical field-shaping elements

Abstract

The present invention provides a process for producing a light-emitting device capable of achieving high directivity without a cavity, which minimizes occurrence of short circuit at a time of covering a light-emitting element with glass. The present invention further provides a light-emitting device capable of achieving high directivity without a cavity.

After a LED mounted on a wiring board is prepared, a glass member having a shape approximated by a rectangular solid or a sphere is placed on the LED. In this step, the glass member is placed so that the central axis of the glass member placed on the LED is present in a region from the central axis of LED to a position inside from the periphery of LED, and that the area of the region is at most 90% of the area of entire surface on which the glass member is placed. Thereafter, the glass member is softened by a heat treatment to cover the LED with the glass member so that a shape that the central axis of LED substantially agrees with the central axis of the glass member in a self-alignment manner.

Claims

1. A process for producing light-emitting device comprising a step of preparing a light-emitting element mounted on a wiring board, a step of placing on the light-emitting element a glass member approximated by a rectangular solid or a sphere, and a step of softening the glass member by a heating treatment, wherein the central axis of the glass member placed on the light-emitting element is located in a region centered at the central axis of the light-emitting element and ranting to a position inside from the periphery of the light-emitting element, the area of the region is at most 90% of the area of the entire surface on which the glass member is mounted, and the step of softening the glass member is a step of covering the light-emitting element with the glass member to thereby forming a shape in which the central axis of the light-emitting element substantially agrees with the central axis of the glass member by a self-alignment manner.

4. The process for producing light-emitting device according to claim 1, wherein the step of preparing a light-emitting element mounted on a wiring board comprises a step of preparing a light-emitting element having a substrate, a semiconductor layer on the substrate and an electrode for applying voltage to the semiconductor layer, and a step of mounting the light-emitting element on the wiring board so that the angle between the substrate and the wiring board becomes at most 1°

.

7. The process for producing light-emitting device according to claim 1, wherein the step of mounting a light-emitting element on a wiring board is a step of electrically connecting the electrode with the wiring board via bumps, and the number of bumps is at least 3.

10. The process for producing light-emitting device according to claim 1, wherein the light-emitting element comprises a substrate and a semiconductor layer provided on the substrate;

a side face of the substrate has a taper portion within a predetermined vertical range from the face of the substrate on which the semiconductor layer is provided; and

the step of softening glass member is a step of covering with the glass member the taper portion of the substrate and a portion above the taper portion.

13. The process for producing light-emitting device according to claim 1, wherein the glass member contains TeO₂, B₂O₃ and ZnO as main components.

16. The process for producing light-emitting device according to claim 1, wherein the light-emitting element is any one of an LED and a semiconductor laser.

22. The light-emitting device according to claim 10, wherein the glass member contains TeO₂, B₂O₃ and ZnO as main components.

2. A process for producing light-emitting device comprising a step of preparing a light-emitting element mounted on a wiring board, a step of providing a glass paste on the light-emitting element, a step of baking the glass paste to form a glass member, and a step of softening the glass member by a heating treatment, wherein the step of softening the glass member is a step of covering the light-emitting element with the glass member to thereby forming a shape in which the central axis of the light-emitting element substantially agrees with the central axis of the glass member by a self-alignment manner.

5. The process for producing light-emitting device according to claim 2, wherein the step of preparing a light-emitting element mounted on a wiring board comprises a step of preparing a light-emitting element having a substrate, a semiconductor layer on the substrate and an electrode for applying voltage to the semiconductor layer, and a step of mounting the light-emitting element on the wiring board so that the angle between the substrate and the wiring board becomes at most 1°

.

8. The process for producing light-emitting device according to claim 2, wherein the step of mounting a light-emitting element on a wiring board is a step of electrically connecting the electrode with the wiring board via bumps, and the number of bumps is at least 3.

11. The process for producing light-emitting device according to claim 2, wherein the light-emitting element comprises a substrate and a semiconductor layer provided on the substrate;

a side face of the substrate has a taper portion within a predetermined vertical range from the face of the substrate on which the semiconductor layer is provided; and

the step of softening glass member is a step of covering with the glass member the taper portion of the substrate and a portion above the taper portion.

14. The process for producing light-emitting device according to claim 2, wherein the glass member contains TeO₂, B₂O₃ and ZnO as main components.

17. The process for producing light-emitting device according to claim 2, wherein the light-emitting element is any one of an LED and a semiconductor laser.

3. A process for producing light-emitting device comprising a step of preparing a light-emitting element mounted on a wiring board, a step of placing a green sheet on the light-emitting element, a step of baking the green sheet to form a glass member, and a step of softening the glass member by a heating treatment, wherein the step of softening the glass member is a step of covering the light-emitting element with the glass member to thereby forming a shape in which the central axis of the light-emitting element substantially agrees with the central axis of the glass member by a self-alignment manner.

6. The process for producing light-emitting device according to claim 3, wherein the step of preparing a light-emitting element mounted on a wiring board comprises a step of preparing a light-emitting element having a substrate, a semiconductor layer on the substrate and an electrode for applying voltage to the semiconductor layer, and a step of mounting the light-emitting element on the wiring board so that the angle between the substrate and the wiring board becomes at most 1°

.

9. The process for producing light-emitting device according to claim 3, wherein the step of mounting a light-emitting element on a wiring board is a step of electrically connecting the electrode with the wiring board via bumps, and the number of bumps is at least 3.

12. The process for producing light-emitting device according to claim 3, wherein the light-emitting element comprises a substrate and a semiconductor layer provided on the substrate;

a side face of the substrate has a taper portion within a predetermined vertical range from the face of the substrate on which the semiconductor layer is provided; and

the step of softening glass member is a step of covering with the glass member the taper portion of the substrate and a portion above the taper portion.

15. The process for producing light-emitting device according to claim 3, wherein the glass member contains TeO₂, B₂O₃ and ZnO as main components.

18. The process for producing light-emitting device according to claim 3, wherein the light-emitting element is any one of an LED and a semiconductor laser.

19. A light-emitting device comprising a wiring board;

a light-emitting element having a substrate of rectangular shape in a front view, a semiconductor layer on the substrate, and an electrode electrically connected with the wiring board and for applying voltage to the semiconductor layer; and

a glass member for covering the light-emitting element;

wherein entirety of the glass member is substantially spherical, the light-emitting element is embedded in a part of the glass member, a curved face of the glass member contacts with a side face of the light-emitting element, and a radius R of a sphere approximating the glass member and the length L of a diagonal line of the substrate satisfy a relation;

L<

2R≦

3L.

21. The light-emitting device according to claim 19, wherein the glass member contains TeO₂, B₂O₃ and ZnO as main components.

23. The light-emitting device according to claim 19, wherein the light-emitting element is any one of an LED and a semiconductor laser.

20. A light-emitting device comprising a wiring board;

a light-emitting element having a substrate of rhombic shape or parallelogram shape in a front view, a semiconductor layer on the substrate, and an electrode electrically connected with the wiring board and for applying voltage to the semiconductor layer; and

a glass member for covering the light-emitting element;

wherein entirety of the glass member is substantially spherical, the light-emitting element is embedded in a part of the glass member, a curved face of the glass member contacts with a side face of the light-emitting element, and a radius R of a sphere approximating the glass member and the length L of one of diagonal lines whichever longer of the substrate satisfy a relation;

L<

2R≦

3L.

24. The light-emitting device according to claim 20, wherein the light-emitting element is any one of an LED and a semiconductor laser.