Light emitting apparatus and method of manufacturing the same

• US 7,301,175 B2
• Filed: 09/30/2003
• Issued: 11/27/2007
• Est. Priority Date: 10/12/2001
• Status: Active Grant

• Current Assignee: Nichia Corporation
• Original Assignee: Nichia Corporation
• Inventors: Sakamoto, Keiji, Izuno, Kunihiro, Sano, Masahiko, Nagahama, Shinichi, Yanamoto, Tomoya, Matsumoto, Kouki
• Primary Examiner(s): TRAN, MINH LOAN
• Application Number:
  US10/673,273
• Publication Number:
  US 20040061433A1
• Time in Patent Office: 1,519 Days
• Field of Search: 257/95, 257/96, 257/97, 257 98-100, 257/40, 257/103, 257/E33.059, 257/E33.061, 313/696, 313/697, 313/691
• US Class Current: 257/98
• CPC Class Codes: H01L 21/76251 using bonding techniques
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/29111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/2919 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/32257 the layer connector connecting to a bonding area disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/49107 on the semiconductor or solid-state body
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/8592 Applying permanent coating, e.g. protective coating
• CPC Class Codes: H01L 24/29 of an individual layer connector
• 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 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01012 Magnesium [Mg]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 Silicon [Si]
• CPC Class Codes: H01L 2924/01019 : Potassium [K]
• CPC Class Codes: H01L 2924/0102 : Calcium [Ca]
• CPC Class Codes: H01L 2924/01021 : Scandium [Sc]
• CPC Class Codes: H01L 2924/01025 : Manganese [Mn]
• CPC Class Codes: H01L 2924/01026 : Iron [Fe]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01037 : Rubidium [Rb]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01049 : Indium [In]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01057 : Lanthanum [La]
• CPC Class Codes: H01L 2924/01063 : Europium [Eu]
• CPC Class Codes: H01L 2924/01066 : Dysprosium [Dy]
• CPC Class Codes: H01L 2924/01067 : Holmium [Ho]
• CPC Class Codes: H01L 2924/01068 : Erbium [Er]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01077 : Iridium [Ir]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/0132 : Binary Alloys
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/0133 : Ternary Alloys
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/09701 : Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/12036 : PN diode
• CPC Class Codes: H01L 2924/12041 : LED
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/157 : with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/3025 : Electromagnetic shielding
• CPC Class Codes: H01L 2924/351 : Thermal stress
• CPC Class Codes: H01L 2924/3512 : Cracking
• CPC Class Codes: H01L 33/32 : containing nitrogen
• CPC Class Codes: H01L 33/44 : characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/483 : Containers
• CPC Class Codes: H01L 33/501 : characterised by the materials, e.g. binder
• CPC Class Codes: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

A light emitting apparatus comprising a light emitting device (101) disposed on a supporting body (105), and coating layers ((108, 109) that bind a fluorescent substance that absorbs light emitted by the light emitting device (101) and emits light of a different wavelength and secures the fluorescent substance onto the surface of the light emitting device (101). The coating layers (108, 109) are made of an inorganic material including an oxide and a hydroxide, each containing at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals. Also an adhesive layer (110) is made of the same inorganic material as that of the coating layers (108, 109).

Claims

1. A light emitting apparatus comprising:

a light emitting device disposed on a supporting body; and

a coating layer comprising a fluorescent substance and covering at least a surface of said light emitting device, said fluorescent substance absorbs at least a portion of light emitted by said light emitting device and emits light of a different wavelength;

wherein said coating layer comprises an oxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals, and a hydroxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals

wherein said coating layer covers the surface of said supporting body and the entire surface of said light emitting device, and the thickness of said coating layer on a top surface, a side face and a corner of said light emitting device and the thickness of said coating layer on a surface of said supporting body are substantially the same.

2. A light emitting apparatus comprising:

a light emitting device disposed on a supporting body; and

a coating layer comprising a fluorescent substance and covering at least a surface of said light emitting device, said fluorescent substance absorbs at least a portion of light emitted by said light emitting device and emits light of a different wavelength;

wherein said coating layer comprises an oxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals, and a hydroxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals

wherein said coating layer comprises at least two layers, each layer having a refractive index that is smaller than that of a nitride semiconductor of said light emitting device, and the refractive index of each layer decreases gradually with the distance from said light emitting device.

3. A light emitting apparatus comprising:

a light emitting device disposed on a supporting body; and

a coating layer comprising a fluorescent substance and covering at least a surface of said light emitting device, said fluorescent substance absorbs at least a portion of light emitted by said light emitting device and emits light of a different wavelength;

wherein said coating layer comprises an oxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals, and a hydroxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals

wherein said light emitting device is disposed so as to oppose the top surface of said supporting body via an adhesive layer, while the adhesive layer contains the same material as that of said coating layer.

4. The light emitting apparatus according to 3,

wherein said adhesive layer contains particles of an oxide and a hydroxide.

5. The light emitting apparatus according to 3,

wherein said adhesive layer extends over a side face of said light emitting device.

6. A light emitting apparatus comprising:

a light emitting device disposed on a supporting body; and

a coating layer comprising a fluorescent substance and covering at least a surface of said light emitting device, said fluorescent substance absorbs at least a portion of light emitted by said light emitting device and emits light of a different wavelength;

wherein said coating layer comprises an oxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals, and a hydroxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals

wherein said light emitting device has an emission peak at a wavelength from 250 nm to 530 nm, and an emission wavelength of said fluorescent substance is longer than a wavelength of the main emission peak of said light emitting device.

7. A light emitting apparatus comprising:

a light emitting device disposed on a supporting body; and

a coating layer comprising a fluorescent substance and covering at least a surface of said light emitting device, said fluorescent substance absorbs at least a portion of light emitted by said light emitting device and emits light of a different wavelength;

wherein said coating layer comprises an oxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals, and a hydroxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals

wherein said fluorescent substance is yttrium aluminum garnet-containing fluorescent substance that includes;

Y;

Al;

at least one element selected from the group consisting of Lu, Sc, La, Gd, Tb, Eu and Sm; and

at least one element selected from the group consisting of Ga and In,

and said fluorescent substance is activated with a rare earth element.

8. A light emitting apparatus comprising:

a light emitting device disposed on a supporting body; and

a coating layer comprising a fluorescent substance and covering at least a surface of said light emitting device, said fluorescent substance absorbs at least a portion of light emitted by said light emitting device and emits light of a different wavelength;

wherein said coating layer comprises an oxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals, and a hydroxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals

wherein said fluorescent substance includes;

N;

at least one element selected from the group consisting of Be, Mg, Ca, Sr, Ba and Zn;

at least one element selected from the group consisting of C, Si, Ge, Sn, Ti, Zr and Hf; and

a nitride-containing fluorescent substance activated with a rare earth element.

9. A light emitting apparatus comprising:

a supporting body;

an adhesive layer, and a light emitting device comprising a gallium nitride-containing compound semiconductor layer, said light emitting device being disposed on said supporting substrate via the adhesive layer;

wherein said adhesive layer comprises an oxide containing at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals, and a hydroxide containing at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals,

wherein said adhesive layer extends over a side face of the light emitting device.

10. A light emitting apparatus comprising:

a supporting body;

an adhesive layer, and a light emitting device comprising a gallium nitride-containing compound semiconductor layer, said light emitting device being disposed on said supporting substrate via the adhesive layer;

wherein said adhesive layer comprises an oxide containing at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals, and a hydroxide containing at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals,

wherein said light emitting device has a main emission peak at a wavelength in a range from 250 nm to 530 nm.

11. A light emitting apparatus comprising:

a supporting body;

an adhesive layer, and a light emitting device comprising a gallium nitride-containing compound semiconductor layer, said light emitting device being disposed on said supporting substrate via the adhesive layer;

wherein said adhesive layer comprises an oxide containing at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals, and a hydroxide containing at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals,

wherein the adhesive layer comprises a filler having a heat conductivity higher than that of said oxide.

12. A light emitting apparatus comprising:

a light emitting device disposed on a supporting body; and

a coating layer comprising a fluorescent substance and covering at least a surface of said light emitting device, said fluorescent substance absorbs at least a portion of light emitted by said light emitting device and emits light of a different wavelength;

wherein said coating layer comprises an oxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals, and a hydroxide including at least one element selected from the group consisting of Si, Al, Ga, Ti, Ge, P, B, Zr, Y, Sn, Pb and alkali earth metals

wherein said light emitting device includes;

a support substrate;

a junction layer that is formed on one principal surface of the support substrate, said junction layer having a eutectic layer; and

stacked layers comprising a p-type nitride semiconductor layer of single-layer or multi-layer structure formed on the junction layer, an active layer formed on the p-type nitride semiconductor layer, and an n-type nitride semiconductor layer of single-layer or multi-layer structure formed on the active layer.

13. The light emitting apparatus according to 12,

wherein at least part of a surface of the stacked layers has a concave-convex shape.