JP2006005067A - Light emitting device - Google Patents

Light emitting device Download PDF

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Publication number
JP2006005067A
JP2006005067A JP2004178267A JP2004178267A JP2006005067A JP 2006005067 A JP2006005067 A JP 2006005067A JP 2004178267 A JP2004178267 A JP 2004178267A JP 2004178267 A JP2004178267 A JP 2004178267A JP 2006005067 A JP2006005067 A JP 2006005067A
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JP
Japan
Prior art keywords
light
emitting device
formed
light emitting
layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2004178267A
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Japanese (ja)
Inventor
Shota Shimonishi
Atsushi Tsuzuki
Takayoshi Yajima
Toshio Yamaguchi
正太 下西
寿夫 山口
孝義 矢嶋
敦 都築
Original Assignee
Toyoda Gosei Co Ltd
豊田合成株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyoda Gosei Co Ltd, 豊田合成株式会社 filed Critical Toyoda Gosei Co Ltd
Priority to JP2004178267A priority Critical patent/JP2006005067A/en
Publication of JP2006005067A publication Critical patent/JP2006005067A/en
Pending legal-status Critical Current

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    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/47Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/484Connecting portions
    • H01L2224/4847Connecting portions the connecting portion on the bonding area of the semiconductor or solid-state body being a wedge bond
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/42Wire connectors; Manufacturing methods related thereto
    • H01L2224/47Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/49Structure, shape, material or disposition of the wire connectors after the connecting process of a plurality of wire connectors
    • H01L2224/491Disposition
    • H01L2224/49105Connecting at different heights
    • H01L2224/49107Connecting at different heights on the semiconductor or solid-state body
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L2224/00Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/73Means for bonding being of different types provided for in two or more of groups H01L2224/10, H01L2224/18, H01L2224/26, H01L2224/34, H01L2224/42, H01L2224/50, H01L2224/63, H01L2224/71
    • H01L2224/732Location after the connecting process
    • H01L2224/73251Location after the connecting process on different surfaces
    • H01L2224/73265Layer and wire connectors

Abstract

PROBLEM TO BE SOLVED: To reduce variation in chromaticity of light emitted by being converted by a phosphor and to make an introspection inspection.
A light emitting device includes an insulating substrate such as sapphire, a semiconductor layer formed by stacking a nitride semiconductor layer on the surface of the substrate, and a YAG formed on the back surface of the substrate. : It is comprised from the fluorescent substance layer 4 which consists of Ce.
[Selection] Figure 1

Description

  The present invention relates to a light-emitting device, and more particularly to a light-emitting device that reduces the variation in chromaticity of light that is converted and emitted by a phosphor and enables an introspection inspection.

  Conventionally, an LED and a phosphor are combined, the phosphor is excited by light emitted from the LED, and converted into light of a different color from the emitted light by mixing excitation light and emitted light emitted based on the excitation. A light emitting device is provided. As a typical structure of such a light-emitting device, a phosphorescent conversion LED device that converts light emitted from an LED into light of a different color using phosphorescence conversion is known (see, for example, Patent Document 1). .

FIG. 3 is a cross-sectional view showing an LED device as a conventional light emitting device. The LED device 100 includes a substrate 101 made of an insulating material such as sapphire, and, for example, two n-type GaN layers, SQW or MQW GaInN layers, p-type AlGaN layers, and p-type formed on the substrate 101. A light emitting structure 102 including a GaN layer and a phosphorescent thin film 103 as a phosphor formed on the light emitting structure 102 are included. Here, the phosphorescent thin film 103 is formed such that phosphorescent powder represented by YAG: Ce doped with cerium is dispersed, for example.
Japanese Patent Laid-Open No. 2001-244507 ([0004] to [0005], FIG. 2)

  However, according to the light emitting device described in Patent Document 1, in the combination of the LED and the phosphor, the phosphorescent thin film 103 as the phosphor is formed so that phosphorescent powder is dispersed. There is a problem of becoming. That is, in the conventional light emitting device, phosphorescent powder as a dopant is dispersed in the phosphorescent thin film 103, so that the light emitted from the light emitting device has a small deviation from the target chromaticity, or conversely a large deviation. Is likely to occur. There is also a problem that defective products cannot be excluded because the interior inspection of the light emitting device is impossible.

  Accordingly, an object of the present invention is to provide a light emitting device that can reduce the variation in chromaticity of light that is converted by a phosphor and emits light, and enables an interior inspection.

  In order to achieve the above object, the present invention is a light emission having a phosphor layer that is excited by light emitted from a semiconductor layer formed on the surface of an insulating substrate to generate excitation light and emit light different from the excitation light. In the device, the phosphor layer is formed on the back surface of the insulating substrate.

  The phosphor layer is preferably formed by sputtering using a target containing a desired phosphor material.

  The semiconductor layer is preferably formed by stacking nitride semiconductors.

  The insulating substrate is preferably made of sapphire.

  The semiconductor layer preferably emits blue light, and the phosphor layer is preferably a phosphor layer that is excited by the blue light and emits yellow light.

  According to the light emitting device of the present invention, since the phosphor layer is formed on the back surface opposite to the surface of the insulating substrate on which the semiconductor layer is formed, the variation in chromaticity of the light converted and emitted by the phosphor is reduced. In addition, the introspection can be made possible.

(Configuration of light emitting device)
FIG. 1 is a cross-sectional view showing a light emitting device according to an embodiment of the present invention. The light emitting device 1 includes a substrate 2 made of sapphire, a semiconductor layer 3 formed by laminating a nitride semiconductor layer on the surface of the substrate 2, and a phosphor layer made of YAG: Ce formed on the back surface of the substrate 2. 4.

  The semiconductor layer 3 includes an n-type GaN layer 5, an n-type AlGaN layer 6, an undoped GaN layer 7, a p-type AlGaN layer 8, and a p-type GaN layer 9 that are sequentially stacked on the surface of the substrate 2. A p-electrode 10 formed on the surface of the p-type GaN layer 9 and an n-electrode 11 formed on the surface of the n-type GaN layer 5 are included. Such a semiconductor layer 3 constitutes a GaN-based LED having a DH (double hetero) structure that emits ultraviolet light. In this LED, the p-electrode 10 and the n-electrode 11 are electrically connected to a wiring (not shown) by bonding wires 12 and 13 respectively.

  The phosphor layer 4 was formed by sputtering using a target obtained by sintering a material obtained by mixing YAG: Ce powder with a binder made of an organic solvent. Sputtering is performed, for example, by adjusting conditions such as electric power and pressure so that the phosphor layer 4 having a required film thickness can be obtained in a gas atmosphere containing argon and oxygen.

  Next, with reference to FIG. 2, the manufacturing method of the light-emitting device 1 is demonstrated in order of a process.

  First, as shown in FIG. 2A, using a substrate 2 made of sapphire, an n-type GaN layer 5 and an n-type AlGaN layer 6 are formed on the surface of the substrate 2 by metal organic chemical vapor deposition (MOVPE). Then, an undoped GaN layer 7, a p-type AlGaN layer 8, and a p-type GaN layer 9 are sequentially stacked. Other crystal growth methods other than MOVPE can also be used.

  Next, as shown in FIG. 2B, etching is performed from the p-type GaN layer 9 toward the n-type GaN layer 5 to expose a part of the n-type GaN layer 5. The n-electrode 11 is formed on the exposed surface 5 and the p-electrode 10 is formed on the surface of the p-type GaN layer 9 to complete the semiconductor layer 3.

  Next, as shown in FIG. 2 (c), a target is prepared by sintering a material obtained by mixing YAG: Ce powder with a binder made of an organic solvent, and sputtering is performed on the back surface of the substrate 1 using this target. The phosphor layer 4 is formed. The film thickness of the phosphor layer 4 can be accurately controlled to a required value by sputtering.

  Next, the whole including the light emitting structure is mounted on a conductor such as a mount substrate or a lead frame (not shown), and the electrodes 10 and 11 are electrically connected to wires (not shown) by wires 12 and 13, thereby providing a light emitting device. Complete 1

  In the light emitting device 1 described above, a forward bias is applied between the p electrode 9 and the n electrode 10 by a power source (not shown), so that the semiconductor layer 3 emits ultraviolet light and the phosphor layer 4 passes through the transparent substrate 2. Excited. As a result, the phosphor layer 4 emits yellow light, and the phosphor layer 4 mixes the yellow light with ultraviolet light to convert it into white.

(Effect of embodiment)
According to the above-described embodiment, the following effects can be obtained.

(1) Since the phosphor layer 4 is formed by sputtering on the back surface of the substrate 2 opposite to the surface on which the semiconductor layer 3 is formed, the film thickness of the phosphor layer 4 can be easily controlled with high accuracy.

(2) Since the thickness of the phosphor layer 4 can be controlled in this way, the variation in chromaticity of light emitted from the light emitting device 1 can be suppressed, so that the chromaticity can be easily adjusted. In addition, the chromaticity can be easily selected.

(3) Further, since the phosphor layer 4 is formed on the back surface of the substrate 2, an introspection can be performed, so that the LED characteristics can be grasped in the manufacturing process, and defective products can be easily excluded.

(Other embodiments)
As another embodiment of the present invention, a GaN-based semiconductor layer that emits blue light is formed on the surface of the substrate 2 and a phosphor layer that emits yellow light as described above is formed on the back surface of the substrate 2 by sputtering. Thus, a light-emitting device that emits white light can be obtained in the same manner as in the above-described embodiment.

  Effects similar to those of the above-described embodiments can be obtained by other embodiments. Furthermore, since the separation of both colors, which has been easy to occur in the past by the combination of blue and yellow, can be reduced, it is possible to emit clean white light.

  The embodiment of the present invention has been described in detail above, but the specific configuration is not limited to the embodiment, and design changes and the like without departing from the gist of the present invention are included in the present invention. It is. For example, although the example using sapphire has been described as the substrate, other insulating substrates can be used without being limited to sapphire.

  In addition, the semiconductor layer formed on the substrate surface has been described with an example in which the semiconductor layer is formed of a GaN-based nitride semiconductor, but is not limited thereto, and may be formed of another semiconductor such as a GaP-based or GaAs-based semiconductor. Moreover, although the phosphor layer formed on the back surface of the substrate has been described as an example using YAG: Ce, the phosphor layer is not limited to this, and is a phosphor material that emits a desired color when excited by light emitted from the semiconductor layer. Can be selected as appropriate.

  In the embodiment of the present invention described above, a mixture of excitation light and ultraviolet light obtained by exciting a phosphor made of YAG: Ce with ultraviolet light emitted from an LED made of a GaN-based nitride semiconductor. Although the light emitting device 1 that obtains white light based on the above has been described, white light may be obtained by mixing RGB three colors by exciting RGB phosphors with ultraviolet light emitted from an LED. For RGB phosphors, targets can be prepared by mixing phosphors and sintering together with a binder so that white light can be obtained.

It is sectional drawing which shows the light-emitting device which concerns on embodiment of this invention. It is sectional drawing shown to the manufacturing method process order of the light-emitting device which concerns on embodiment of this invention. It is sectional drawing which shows the LED device as a conventional light-emitting device.

Explanation of symbols

1, light emitting device 2, insulating substrate 3, light emitting structure 4, phosphor layer 5, n-type GaN layer 6, n-type GaN layer 7, undoped GaN layer 8, p-type AlGaN layer 9, p-type GaN layer 10, p-electrode 11, n-electrodes 12, 13, wire 100, LED device 103, phosphorescent thin film 102, light-emitting structure 101, substrate

Claims (5)

  1. In a light emitting device having a phosphor layer that is excited by light emitted from a semiconductor layer formed on the surface of an insulating substrate to generate excitation light and emits light different from the excitation light,
    The phosphor layer is formed on a back surface of the insulating substrate.
  2.   The light emitting device according to claim 1, wherein the phosphor layer is formed by sputtering using a target containing a desired phosphor material.
  3.   The light emitting device according to claim 1, wherein the semiconductor layer is formed by stacking nitride semiconductors.
  4.   The light-emitting device according to claim 1, wherein the insulating substrate is made of sapphire.
  5.   5. The light emitting device according to claim 1, wherein the semiconductor layer emits blue light, and the phosphor layer emits yellow light when excited by the blue light.
JP2004178267A 2004-06-16 2004-06-16 Light emitting device Pending JP2006005067A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2004178267A JP2006005067A (en) 2004-06-16 2004-06-16 Light emitting device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2004178267A JP2006005067A (en) 2004-06-16 2004-06-16 Light emitting device

Publications (1)

Publication Number Publication Date
JP2006005067A true JP2006005067A (en) 2006-01-05

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008108871A (en) * 2006-10-25 2008-05-08 Stanley Electric Co Ltd Mounting structure for semiconductor light-emitting element
JP4778107B1 (en) * 2010-10-19 2011-09-21 有限会社ナプラ Light emitting device and manufacturing method thereof

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008108871A (en) * 2006-10-25 2008-05-08 Stanley Electric Co Ltd Mounting structure for semiconductor light-emitting element
JP4778107B1 (en) * 2010-10-19 2011-09-21 有限会社ナプラ Light emitting device and manufacturing method thereof
US8766312B2 (en) 2010-10-19 2014-07-01 Napra Co., Ltd. Light-emitting device comprising vertical conductors and through electrodes and method for manufacturing the same

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