LIGHT EMITTING DEVICE AND METHOD OF MANUFACTURING THE SAME

• US 20160190395A1
• Filed: 12/21/2015
• Published: 06/30/2016
• Est. Priority Date: 12/26/2014
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: SHIRAHAMA, Satoshi
• Granted Patent: US 9,905,740 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 33/486 adapted for surface mounting
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]
• CPC Class Codes: H05K 2201/10234 Metallic balls solder balls H05K2203/041
• CPC Class Codes: H05K 3/3431 Leadless components
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A light emitting device includes a light emitting element, a light-reflecting substrate, and an electrically conductive member. The light emitting element includes a first surface and an electrode provided on the first surface. The light-reflecting substrate has a first main surface facing the first surface of the light emitting element and has a second main surface opposite to the first main surface. The light-reflecting substrate defines a hole at a position corresponding to the electrode. The hole penetrates through the light-reflecting substrate from the first main surface to the second main surface. The electrically conductive member includes a substantially spherical core arranged in the hole and bonded with the electrode, and a coating portion provided in a space between the substantially spherical core and a lateral surface of the hole.

Claims

1. A light emitting device comprising:

a light emitting element including a first surface and an electrode provided on the first surface;

a light-reflecting substrate having a first main surface facing the first surface of the light emitting element and having a second main surface opposite to the first main surface, and defining a hole at a position corresponding to the electrode, the hole penetrating through the light-reflecting substrate from the first main surface to the second main surface; and

an electrically conductive member including a substantially spherical core arranged in the hole and bonded with the electrode, and a coating portion provided in a space between the substantially spherical core and a lateral surface of the hole.

2. The light emitting device according to claim 1,

wherein an opening diameter of the hole on the second main surface is equal to or larger than a diameter of the substantially spherical core, and

wherein an opening diameter of the hole on the first main surface is smaller than the diameter of the substantially spherical core.

3. The light emitting device according to claim 1,

wherein the hole has a tapered shape narrowing from the second main surface toward the first main surface.

4. The light emitting device according to claim 1,

wherein the lateral surface of the hole has an irregularity.

5. The light emitting device according to claim 1,

wherein the substantially spherical core contacts the lateral surface of the hole.

6. The light emitting device according to claim 1,

wherein the substantially spherical core protrudes from the second main surface.

7. The light emitting device according to claim 1,

Wherein, in a plan view, the electrode is accommodated within the hole.

8. The light emitting device according to claim 1,

wherein a melting point of the coating portion is lower than a melting point of the substantially spherical core.

9. The light emitting device according to claim 1,

wherein the substantially spherical core contains Cu, and

wherein the coating portion is made of alloy that contains Au and at least one kind among Si, Ge, and Sn.

12. The light emitting device according to claim 1, further comprising:

a second electrically conductive member comprising;

a second substantially spherical core; and

a second coating portion,

wherein the electrode of the light emitting element is a positive electrode,

wherein the light emitting element has a negative electrode provided on the first surface,

wherein the light-reflecting substrate defines a second hole penetrating from the first main surface to the second main surface of the light-reflecting substrate at a location corresponding to the negative electrode,

wherein the second substantially spherical core is provided in the second hole to be bonded with the negative electrode, and

wherein the second coating portion is provided in a second space between the second substantially spherical core and a lateral surface of the second hole.

10. A method of manufacturing a light emitting device comprising:

providing a light emitting element including a first surface and having an electrode on the first surface;

providing a light-reflecting substrate having

a first main surface and a second main surface opposite to the first main surface, and defining

a hole penetrating from the first main surface to the second main surface of the light-reflecting substrate at a location corresponding to the electrode;

providing a substantially spherical electrically conductive member;

arranging the first surface of the light emitting element and the first main surface of the light-reflecting substrate so that the electrode is exposed in the hole;

arranging the substantially spherical electrically conductive member in the hole; and

bonding the substantially spherical electrically conductive member with the electrode.

11. The method according to claim 10,

wherein the providing of the substantially spherical electrically conductive member includes forming a coating portion that covers a core and has a melting point lower than a melting point of the core, and in the arranging of the substantially spherical electrically conductive member, the substantially spherical electrically conductive member having the core and the coating portion is arranged in the hole, and

wherein the bonding of the substantially spherical electrically conductive member includes melting the coating portion to bond the core with the electrode.

13. The method according to claim 10,

wherein the electrode of the light emitting element is a positive electrode,

wherein the light emitting element has a negative electrode provided on the first surface,

wherein the light-reflecting substrate has a second hole penetrating from the first main surface to the second main surface of the light-reflecting substrate at a location corresponding to the negative electrode,

wherein the arranging of the first surface of the light emitting element and the first main surface of the light-reflecting substrate includes arranging the light emitting element and the light-reflecting substrate so that the negative electrode is exposed in the second hole,

wherein the arranging of the substantially spherical electrically conductive member includes providing a second substantially spherical electrically conductive member in the second hole, and

wherein the bonding of the substantially spherical electrically conductive member with the electrode includes bonding the second substantially spherical electrically conductive member with the negative electrode.