LIGHT EMITTING ELEMENT AND METHOD OF MANUFACTURING THE SAME

• US 20150280065A1
• Filed: 02/25/2015
• Published: 10/01/2015
• Est. Priority Date: 03/28/2014
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: WADA, Satoshi
• Granted Patent: US 9,728,678 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 33/0095 Post-treatment of devices, e.g. annealing, recrystallisation or short-circuit elimination
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/501 characterised by the materials, e.g. binder

Abstract

A light emitting element includes a crystal growth substrate formed in a flat shape and that has a translucency, a semiconductor layer that constitutes a light emitting element structure and is formed at a side of a first surface of the crystal growth substrate, irregularities formed on a second surface of the crystal growth substrate, the second surface being an opposite surface of the first surface, and a protective layer that has a translucency and a predetermined hardness and brittleness, and covers the irregularities formed on the second surface of the crystal growth substrate.

Claims

1. A light emitting element comprising:

a crystal growth substrate formed in a flat shape and that has a translucency;

a semiconductor layer that constitutes a light emitting element structure and is formed at a side of a first surface of the crystal growth substrate;

irregularities formed on a second surface of the crystal growth substrate, the second surface being an opposite surface of the first surface; and

a protective layer that has a translucency and a predetermined hardness and brittleness, and covers the irregularities formed on the second surface of the crystal growth substrate.

2. The light emitting element according to claim 1, wherein the protective layer comprises at least one of phosphors and light-scattering material.

3. The light emitting element according to claim 1, wherein the protective layer is made of a sintered body of mixed particles of combined body particles and glass particles, and the combined body particles are dispersed in a glass, the combined body particles being obtained by mixing and binding phosphors and dispersed binders;

and

wherein the dispersed binders are non-glass materials having a translucency and a binding property to the phosphors.

4. The light emitting element according to claim 1, further comprising:

an optical thin film that covers the whole surface of a front surface side of the protective layer.

5. A method of manufacturing the light emitting element according to claim 1, the method comprising:

a first process for forming the semiconductor layer at a side of a first surface of a wafer of the crystal growth substrate;

a second process for forming the irregularities on a second surface of the wafer of the crystal growth substrate;

a third process for forming the protective layer at a side of the second surface of the wafer of the crystal growth substrate, the protective layer covering the irregularities; and

a fourth process for dividing, the wafer of the crystal growth substrate, the semiconductor layer and the protective layer which are stacked, into a plurality of light emitting elements by adhering a wafer fixing tape to the protective layer and pressing a breaking blade of a breaking device against a dividing line portion on a surface of the protective layer via the wafer fixing tape.