Light emitting device with wavelength converted by phosphor

• US 7,498,734 B2
• Filed: 06/17/2004
• Issued: 03/03/2009
• Est. Priority Date: 06/18/2003
• Status: Expired due to Fees

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Wada, Satoshi, Kato, Hideaki, Suehiro, Yoshinobu, Tohmon, Ryoichi
• Primary Examiner(s): Roy; Sikha
• Assistant Examiner(s): Walford; Natalie K
• Application Number:
  US10/869,036
• Publication Number:
  US 20040257797A1
• Time in Patent Office: 1,720 Days
• Field of Search: 313/502
• US Class Current: 313/502
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• 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 33/505 characterised by the shape, e.g. plate or foil
• 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

Abstract

A light emitting device has a light emitting element portion that radiates light with a predetermined wavelength, and a wavelength conversion portion that surrounds a phosphor to be excited by the light with the predetermined wavelength with a transparent and non-moisture permeability material in the form of laminae. Further, a light emitting device has a plurality of LED elements disposed on a same plane, and a wavelength conversion portion that comprises a flat transparent base member that is disposed opposite to the plurality of LED elements and a phosphor layer that is of a phosphor to be excited by light emitted from the LED element and is formed like a film on the base member. The phosphor layer includes part with no phosphor in plane.

Claims

1. A light emitting device, comprising:

a light emitting element portion that radiates light with a predetermined wavelength; and

a wavelength conversion portion that comprises;

a phosphor layer to be excited by the light with the predetermined wavelength; and

a transparent and non-moisture permeability material including layers that sandwich the phosphor layer, the transparent and non-moisture permeability material comprising low-melting glass,

wherein the phosphor layer consists essentially of a phosphor without a sealing resin.

2. The light emitting device according to claim 1, wherein:

the wavelength conversion portion surrounds and seals the light emitting element portion, and

the phosphor layer is shaped like a thin film and disposed around the light emitting element portion.

3. The light emitting device according to claim 1, wherein:

the wavelength conversion portion has an optical shape to radiate the light according to a desired light distribution characteristic from the light emitting element portion.

4. The light emitting device according to claim 1, wherein:

the wavelength conversion portion is integrally formed such that the phosphor layer formed like a thin film on a surface of a first glass material is sandwiched with a second glass material and then thermally fused.

5. A light emitting device, comprising:

a plurality of LED elements disposed on a same plane; and

a wavelength conversion portion that comprises;

a flat transparent glass base member that is disposed opposite to the plurality of LED elements to allow light extraction through the base member, the flat transparent glass base member comprising a non-moisture permeability material; and

a phosphor layer that comprises a phosphor to be excited by light emitted from the plurality of LED elements and is formed on the base member;

wherein the phosphor layer is a predetermined patterned layer including gaps therein,

the phosphor layer is disposed directly above and at a distance from the plurality of LED elements, and

the phosphor layer consists essentially of the phosphor without a sealing resin.

6. The light emitting device according to claim 5, wherein:

the gaps are located at a region where a light component emitted from the plurality of LED elements and subjected to no reflection in the light emitting device is not allowed to be transmitted through outside the light emitting device.

7. The light emitting device according to claim 5, further comprising:

a plurality of cone-shaped reflection surfaces that are provided corresponding to the plurality of LED elements,

wherein the reflection surfaces are provided with a phosphor layer to be excited by light emitted from the plurality of LED elements.

10. The light emitting device according to claim 5, wherein:

the base member is provided with an uneven surface to give a light diffusion property.

8. A light emitting device, comprising:

a plurality of LED elements disposed on a same plane; and

a wavelength conversion portion that comprises;

a flat transparent glass base member that is disposed opposite to the plurality of LED elements to allow light extraction through the base member, the flat transparent glass base member comprising a non-moisture permeability material; and

a phosphor layer including a phosphor to be excited by light emitted from the plurality of LED elements, the phosphor layer having a predetermined pattern with openings and being sealed in an interior of the flat transparent glass base member while being in the form of a film.

9. The light emitting device according to claim 8, wherein:

the phosphor layer is partially located corresponding to the LED element.