TW201431135A - Ultraviolet light emitting apparatus - Google Patents

Abstract

An ultraviolet light-emitting apparatus of the present invention comprises: a mounting substrate, a plurality of ultraviolet LED chips, a frame member, and window material. According to the ultraviolet light-emitting apparatus of the present invention, when the radiation angle of ultraviolet with respect to the optical axis is denoted as <theta>, the radiation intensity in the direction of <theta> is denoted as I<theta>, and the range of radiation angle <theta> is divided into a first confined range of -90 DEG to 90 DEG, including 0 DEG, and a second confined range having an absolute value greater than any value within the first confined range, the dependence of radiation intensity I<theta> on the radiation angle is smaller than cos<n><theta> in the first confined range and greater than cos<n><theta> in the second confined range by using cos<n><theta> (n is a real number greater than 1) as the reference of the same output. In this manner, a plurality of ultraviolet LED chips are configured to avoid the center of the region and surround the center, wherein the region refers to the area surrounded by the frame member when one surface of the mounting substrate is viewed from the top, thereby achieving the purpose of uniform illumination on a planar surface being illuminated.

Description

Ultraviolet light emitting device

The present invention relates to an ultraviolet light emitting device.

In the past, regarding ultraviolet light-emitting devices, for example, ultraviolet light-emitting LEDs having an emission peak wavelength of 385 nm have been known (refer to, for example, the ultraviolet light-emitting LED standard specification NICHIASTS-DA1-1763C<Cat. No. 120518>, Nichia Chemical Co., Ltd. Industrial Co., Ltd.). Hereinafter, "UV-illuminated LED standard specification NICHIASTS-DA1-1763C<Cat. No. 120518>" is referred to as Document 1. The ultraviolet light-emitting LED described in Document 1 is made of ceramic, and the glass window is made of hard glass/Kovar. In Document 1, regarding the optical characteristics of the ultraviolet light-emitting LED, the directivity as shown in FIG. 17 is described.

In addition, as for the ultraviolet light-emitting device, for example, an ultraviolet LED that emits deep ultraviolet rays is known (see, for example, Japanese Patent Laid-Open Publication No. 2010-285785). Hereinafter, Japanese Patent Laid-Open Publication No. 2010-285785 is referred to as Document 2.

Document 2 describes the use of ultraviolet LEDs as a sterilization mechanism for bacteria. Further, Document 2 describes that the ultraviolet light emitted from the ultraviolet LED is set to have a light-emitting wavelength of between 250 nm and 280 nm, whereby the bacteria and the like can be efficiently sterilized.

Further, Document 2 discloses that an ultraviolet LED can also be used to mount a semiconductor light emitting element to a metal. The purpose of the aspect of the tank or ceramic package.

The directivity shown in Fig. 17, that is, the radiation angle dependence of the intensity of the emitted light, can be approximated by the Lambert type distribution of cos θ when the radiation angle is θ.

Therefore, it is considered that the ultraviolet light-emitting LED described in Document 1 has the same purpose as the ultraviolet light LED described in Document 2 in order to achieve uniformity of illumination on a planar illuminated surface.

Accordingly, an object of the present invention is to provide an ultraviolet light-emitting device which can achieve the purpose of uniformizing the illuminance on a planar illuminated surface.

The ultraviolet light-emitting device of the present invention comprises: a mounting substrate, a plurality of ultraviolet LED chips, a frame, and a window material. The plurality of ultraviolet LED chips are mounted on a surface side of the mounting substrate. The frame is disposed on the one surface side of the mounting substrate so as to surround the plurality of ultraviolet LED chips. The window member is disposed on the one surface side of the mounting substrate so as to cover the frame and the plurality of ultraviolet LED chips. The ultraviolet rays of each of the ultraviolet LED chips can pass through the window material. In the ultraviolet light-emitting device, the radiation angle of the ultraviolet light with respect to the optical axis is θ , the intensity of the radiation light in the radiation angle θ direction is I _θ , and the range of the radiation angle θ is divided into -90° to 90°. when included in a first inner 0 ° and the absolute values defined in a second range greater than the range of values defined within the first defined range, the radiation angle of the radiation intensity _I θ dependency to the same output cos ⁿ θ The reference is smaller than cos ⁿ θ in the first limited range, and larger than cos ⁿ θ in the second limited range. Where n is a real number of 1 or more. The ultraviolet light-emitting device satisfies the plurality of ultraviolet LED chips in a region surrounded by the frame in a plan view of the one surface of the mounting substrate so as to satisfy the radiation angle dependence of the radiation light intensity I _θ , configured to avoid the center of the area and surround the center. Thereby, the ultraviolet light-emitting device can achieve the purpose of uniformizing the illuminance on the planar illuminated surface.

In the ultraviolet light-emitting device, the frame is preferably a reflection portion that reflects ultraviolet rays emitted from the respective ultraviolet LED chips to the side of the window member.

In the ultraviolet light-emitting device, the window member includes a plano-convex aspherical lens portion that controls light distribution of ultraviolet rays emitted from the ultraviolet LED chip, and protrudes outward from the outer peripheral portion of the aspherical lens portion over the entire periphery. Flange. The flange of the window material is joined to the frame. In the window material, the first lens surface on the side close to the mounting substrate is formed by a convex curved surface, and the second lens surface on the side away from the mounting substrate is formed by a flat surface.

1‧‧‧UV illuminating device

2‧‧‧Installation substrate

2a‧‧‧Area

2a1‧‧‧1st

2aa‧‧‧ Center

3‧‧‧UV LED chip

4‧‧‧ frame

4a‧‧‧ inside

5‧‧‧ Window materials

5a‧‧‧Aspheric lens section

5b‧‧‧Flange

5aa‧‧‧1st lens surface

5ab‧‧‧2nd lens surface

7‧‧‧ illuminated surface

10‧‧‧Light source

13‧‧‧Sub-assembly components

13a‧‧‧Substrate

13b‧‧‧1st conductor layer

13bb‧‧‧Wiring Department

17‧‧‧ lead

20‧‧‧Support substrate

21‧‧‧Metal plates

21a1‧‧‧ surface

22‧‧‧Electrical insulation

23‧‧‧2nd conductor layer

23a‧‧‧1st terminal part

23b‧‧‧2nd terminal section

24‧‧‧ Hole Department

26‧‧‧Protective layer

29‧‧‧ Hole Department

H1‧‧‧ height dimensions

H2‧‧‧ height dimension

W1‧‧‧Width

W2‧‧‧Maximum inner diameter

A ₂ , B ₂ , A ₂₂ , B ₂₂ , A ₀₁ , A ₀₂ , A ₀₃ , A ₀₄ , A ₁₁ , A ₁₂ , A ₁₃ , A ₁₄ , A ₂₁ , A ₂₂ , A ₂₃ , A ₂₄ , A ₃₁ , A ₃₂ , A ₃₃ , A ₃₄ , Ax , Ay‧‧‧ light distribution characteristics

The preferred embodiment of the invention is described in more detail. Other features and advantages of the invention will be apparent from the description and appended claims appended claims.

Fig. 1A is a schematic plan view of an ultraviolet light-emitting device of an embodiment. Fig. 1B is a schematic plan view showing a main part of a partially broken ultraviolet light-emitting device according to an embodiment.

Fig. 2 is a schematic exploded perspective view of an ultraviolet light emitting device according to an embodiment.

Fig. 3 is a schematic cross-sectional view showing a main part of an ultraviolet light-emitting device of an embodiment.

Fig. 4 is a schematic explanatory view showing an irradiation range of an ultraviolet light-emitting device of an embodiment.

Fig. 5A is an explanatory view showing a target light distribution characteristic of an ultraviolet light-emitting device according to an embodiment in a polar coordinate. Fig. 5B is an explanatory view showing the light distribution characteristics of the ultraviolet light-emitting device of the comparative example in terms of polar coordinates.

Fig. 6A is an explanatory diagram showing the light distribution characteristics of the point light source in terms of polar coordinates. Fig. 6B is an explanatory diagram showing the light distribution characteristics of the point light source in a rectangular coordinate.

Fig. 7 is an explanatory diagram of a light distribution of a point light source on an illuminated plane.

Fig. 8A is an explanatory view showing a target light distribution characteristic of an ultraviolet light-emitting device according to an embodiment in a polar coordinate. Fig. 8B is an explanatory view showing a target light distribution characteristic of the ultraviolet light-emitting device of the embodiment in a rectangular coordinate.

Fig. 9 is an explanatory view showing a target light distribution of an ultraviolet light-emitting device of an embodiment on an illuminated surface.

Fig. 10 is a view showing an actual measurement example of the light distribution characteristics of the ultraviolet light-emitting device of the embodiment.

Fig. 11 is a view showing an actual measurement example of the light distribution characteristics of the ultraviolet light-emitting device of the embodiment.

Fig. 12 is an explanatory view showing the light distribution characteristics of the ultraviolet light-emitting device of the embodiment.

13A, B, and C are illuminance distribution diagrams of the ultraviolet ray-emitting device of the embodiment.

Fig. 14 is an explanatory view of a main part of a first modified embodiment of the ultraviolet light-emitting device of the embodiment.

Fig. 15 is a illuminance distribution diagram of the first modified embodiment of the ultraviolet light-emitting device according to the embodiment of the present invention.

Fig. 16 is an explanatory view of a main part of a second modified embodiment of the ultraviolet light-emitting device of the embodiment.

Fig. 17 is a directivity diagram of a conventional ultraviolet light emitting LED.

Hereinafter, the ultraviolet light-emitting device 1 of the present embodiment will be described with reference to Figs. 1 to 5 .

The ultraviolet light-emitting device 1 includes a mounting substrate 2, a plurality of ultraviolet LED chips 3, a housing 4, and a window member 5. In the example shown in the figure, six ultraviolet LED chips 3 are provided. The plurality of ultraviolet LED chips 3 are mounted on one mounting substrate 2. The frame 4 is configured to surround the plurality of ultraviolet LED chips 3 on one surface side of the mounting substrate 2. The mounting substrate 2 has a surface and another surface opposite the one surface. Hereinafter, one surface of the mounting substrate 2 is referred to as a first surface 2a1. The window member 5 is disposed so as to cover the frame body 4 and the plurality of ultraviolet LED chips 3 on the first surface 2a1 side of the mounting substrate 2. The window material 5 is an ultraviolet permeable member of each of the ultraviolet LED chips 3.

The plurality of ultraviolet LED chips 3 are disposed in a region 2a surrounded by the frame 4 in a plan view of the first surface 2a1 of the mounting substrate 2. Here, the plurality of ultraviolet LED chips 3 are arranged to avoid the center 2aa of the region 2a and surround the center 2aa. In short, in the ultraviolet light-emitting device 1, the ultraviolet LED chips 3 are not disposed in the central portion of the region 2a, but the plurality of ultraviolet LED chips 3 are disposed only around the region 2a. In the ultraviolet light-emitting device 1, when the radiation angle of the ultraviolet light with respect to the optical axis is θ, the radiation light intensity in the radiation angle θ direction is I _θ , and the radiation angle θ is divided into -90° to 90°. comprising including 0 ° and the absolute values of the first defined range of values greater than the second defined range of the first defined range, the radiation angle of emitted light intensity dependence of _I θ, cos ⁿ θ to the same output The reference is smaller than cos ⁿ θ in the first limited range, and larger than cos ⁿ θ in the second limited range. Where n is a real number of 1 or more. The ultraviolet light-emitting device 1 arranges the plurality of ultraviolet LED chips 3 so as to satisfy the above-described radiation angle dependence of the radiation light intensity I _θ . Thereby, as shown in FIG. 4, the ultraviolet light-emitting device 1 can achieve the purpose of uniformizing the illuminance on the planar illuminated surface 7. In FIG. 4, the traveling path of the ultraviolet rays radiated by the ultraviolet light-emitting device 1 and incident on the illuminated surface 7 is schematically illustrated by a solid line with an arrow. The illuminated surface 7 is a plane that is substantially orthogonal to the optical axis of the ultraviolet light-emitting device 1 and is irradiated with ultraviolet rays of the ultraviolet light-emitting device 1. Here, the same output means the same meaning as the case where the light output has a light distribution characteristic of cos ⁿ θ. Fig. 5A is an explanatory diagram showing the target light distribution characteristics of the ultraviolet light-emitting device 1 in terms of polar coordinates. Fig. 5B is an explanatory view showing the light distribution characteristics of the ultraviolet light-emitting device of the comparative example in terms of polar coordinates.

More specifically, B ₂ in FIG. 5A is an explanatory diagram in which the light distribution characteristics of cos ² θ are represented by polar coordinates. In addition, A ₂ in FIG. 5A is the target of the same output when n=2, the first limited range is -19°<θ<19°, and the second limited range is 19°<| θ |<45°. An illustration of the light distribution characteristics. The ultraviolet light-emitting device 1 has a light distribution characteristic of A ₂ as shown in FIG. 5A, whereby it can be made to be on the planar illuminated surface 7 as compared with the case of having a light distribution characteristic such as B ₂ . The purpose of illuminating is uniform. The numerical values of the first limited range and the second limited range are merely examples, and are not particularly limited.

B ₂₂ in Fig. 5B is an explanatory diagram in which the light distribution characteristics of cos ² θ are represented by polar coordinates. In addition, A ₂₂ in FIG. 5B is an explanatory diagram of light distribution characteristics in which the radiation angle is flattened in the range of -19° to 19° in the light distribution characteristics of cos ² θ. The ultraviolet light-emitting device of the comparative example has the light distribution characteristics of A ₂₂ , whereby when the area of the illuminated surface 7 is set to be the same as that of the ultraviolet light-emitting device of the reference example having the light distribution characteristics of B ₂₂ , the equivalent The excess irradiation energy in the range of the oblique line in FIG. 5B is reduced, thereby achieving the purpose of reducing power consumption.

Hereinafter, each component of the ultraviolet light-emitting device 1 will be described in detail.

The ultraviolet LED chip 3 is an LED chip that emits ultraviolet rays (ultraviolet light). UV LED chip 3, For example, an LED chip in which the material of the light-emitting layer is an AlGaN-based material can be employed. The LED chip, for example, can emit light in an ultraviolet wavelength range of an emission wavelength of 210 nm to 360 nm.

The ultraviolet LED chip 3 may be, for example, an LED wafer in which an AlN layer, an n-type nitride semiconductor layer, a light-emitting layer, an electron blocking layer, a p-type nitride semiconductor layer, and a p-type contact layer are stacked on one surface side of the sapphire substrate. The ultraviolet LED chip 3 may have a structure including a first electrode electrically connected to the n-type nitride semiconductor layer and a second electrode electrically connected to the p-type nitride semiconductor layer through the p-type contact layer. The n-type nitride semiconductor layer is composed of, for example, an n-type Al _x Ga _1-x N (0 < x < 1) layer. The light-emitting layer has a quantum well structure composed of an AlGaN-based material. The quantum well structure is composed of a barrier layer and a well layer. The quantum well structure can be a multiple quantum well structure or a single quantum well structure. The UV LED wafer 3 can also form a dual hybrid structure. In the ultraviolet LED wafer 3, the light-emitting layer may have a single-layer structure, or a double-hybrid structure may be formed by the film layers on both sides in the thickness direction of the light-emitting layer and the light-emitting layer. As the film layers on both sides in the thickness direction of the light-emitting layer, for example, an n-type nitride semiconductor layer and a p-type nitride semiconductor layer can be used. Further, the structure of the ultraviolet LED chip 3 is not particularly limited.

The light-emitting layer sets the composition ratio of Al of the well layer in such a manner as to emit ultraviolet rays of a desired light-emitting wavelength. The light-emitting layer composed of the AlGaN-based material can be set to an arbitrary light-emitting wavelength in a range of 210 to 360 nm by changing the composition ratio of Al. For example, when the ultraviolet light-emitting device 1 is used for sterilization of bacteria or the like, the light-emitting wavelength of the ultraviolet LED chip 3 may be appropriately set within a range of, for example, 250 nm to 280 nm. For example, when the emission wavelength of the ultraviolet LED chip 3 is 265 nm, the composition ratio of Al may be set to about 0.50.

The ultraviolet LED wafer 3 was set to have a wafer size of 0.39 mm square (0.39 mm × 0.39 mm). The wafer size of the LED wafer is not particularly limited, and for example, a size of 0.3 mm square, 0.45 mm square, or 1 mm square can be used.

Further, the ultraviolet LED chip has a thickness of about 0.16 mm, but is not particularly limited.

The ultraviolet LED chip 3 can be disposed such that the first electrode and the second electrode are disposed on the same surface side. Made. The ultraviolet LED chip 3 is electrically connected to the first conductor layer 13b of the mounting substrate 2 through a bump (not shown). When the first conductor layer 13b is viewed from each of the ultraviolet LED chips 3, the first portion to which the first electrode is connected and the second portion to which the second electrode is connected are electrically insulated to form a predetermined pattern. In the ultraviolet LED chip 3, the structure of the first electrode and the second electrode is disposed on one surface side in the thickness direction of the ultraviolet LED chip 3, and light is taken out from the one surface side. At this time, in the ultraviolet LED chip 3, the first electrode can be electrically connected to the first portion through the first lead, and the second electrode can be electrically connected to the second portion through the second lead. For the first lead and the second lead, for example, an Au wire, an Al wire, an Al-Si wire, a Cu wire, or the like can be used.

The ultraviolet LED chip 3 is not limited to the LED chip in which the first electrode and the second electrode are provided on one surface side in the thickness direction of the ultraviolet LED chip 3. The ultraviolet LED chip 3 may be, for example, an LED chip in which a first electrode is provided on one surface side in the thickness direction of the ultraviolet LED wafer 3 and a second electrode is provided on the other surface side. In this case, the ultraviolet LED chip 3 is such that one of the first electrode and the second electrode is transmitted through the conductive bonding material to the first conductor layer 13b, and the other is electrically connected to the other first conductor layer 13b. Just fine. As the lead wire, for example, an Au wire, an Al wire, an Al-Si wire, a Cu wire, or the like can be used. As the conductive bonding material, for example, solder or Ag paste or the like can be used.

In the ultraviolet light-emitting device 1, the number of the ultraviolet LED chips 3 can be set to six, and the six ultraviolet LED chips 3 are placed on the first surface 2a1 of the mounting substrate 2 on the circumference of one imaginary circle surrounding the center. Configured at roughly equal intervals. The number of the ultraviolet LED chips 3 is not limited to six. The number of the ultraviolet LED chips 3 can be plural. The number of the ultraviolet LED chips 3 is preferably three or more, and more preferably four or more.

The mounting substrate 2 is a substrate on which the ultraviolet LED chip 3 is mounted. The term "installation" includes the concept of arranging the ultraviolet LED chip 3 and mechanically and electrically connecting it. Therefore, the mounting substrate 2 has a function of mechanically holding the ultraviolet LED chip 3 and a function of forming wiring for supplying power to the ultraviolet LED chip 3. The substrate 2 is mounted, and a plurality of ultraviolet LED chips 3 can be mounted. The substrate 2 is mounted, for example, six ultraviolet LED chips 3 can be mounted.

The mounting substrate 2 may include a sub-carrier member 13 having the above-described first conductor layer 13b, and a flat The face size is larger than the sub-carrier member 13 and supports the support substrate 20 of the sub-carrier member 13.

The support substrate 20 may include a metal plate 21 and an electrical insulating layer 22 formed on one surface 21a1 side of the metal plate 21. The support substrate 20 may include a hole portion 24 formed in the electrically insulating layer 22 to expose a part of one surface 21a1 of the metal plate 21, and two second conductor layers 23 for power supply formed on the electrically insulating layer 22. The sub-carrier member 13 is disposed inside the hole portion 24 formed by the electrically insulating layer 22. The sub-carrier member 13 is joined to one surface 21a1 side of the metal plate 21. The second conductor layer 23 has a first terminal portion 23a and a second terminal portion 23b. In the mounting board 2, one of the two second terminal portions 23b constitutes an external connection terminal on the high potential side, and the other of the two second terminal portions 23b constitutes an external connection terminal on the low potential side.

The sub-carrier member 13 may include a base material 13a and a first conductor layer 13b. The substrate 13a has a higher thermal conductivity than the electrically insulating layer 22 and is electrically insulating. The first conductor layer 13b is formed on the opposite surface side of the metal plate 21 side of the base material 13a. The first conductor layer 13b has two wiring portions 13bb formed on the outer surface of the region surrounded by the frame body 4 on one surface of the base material 13a and the outer region of the casing 4.

In the mounting substrate 2, the wiring portion 13bb disposed adjacent to each other in plan view is electrically connected to the first terminal portion 23a through the lead wires 17. Thereby, the mounting substrate 2 can be provided with two lead wires 17. Further, in the ultraviolet light-emitting device 1 of the present embodiment, wiring is formed by the first conductor layer 13b, the respective second conductor layers 23, and the respective leads 17.

The outer peripheral shape of the metal plate 21 is a rectangle. In addition, the rectangle contains the concept of a rectangle and a square. Further, the outer peripheral shape of the metal plate 21 is not limited to a rectangular shape, and may be, for example, a polygonal shape such as a circular shape or a rectangular shape.

The material of the metal plate 21 is preferably a metal having a high thermal conductivity. Therefore, the material of the metal plate 21 is copper. The material of the metal plate 21 is not limited to copper. For example, aluminum, aluminum alloy, silver, phosphor bronze, copper alloy, nickel alloy or the like can also be used. The copper alloy is, for example, a 42 alloy or the like. The metal plate 21 may be provided with a surface treatment layer (not shown) on the surface of the base material composed of the above materials. As the surface treatment layer, for example, a single layer film of an Au film, an Al film, an Ag film, or the like can be used. Surface treatment layer, not limited to single As the layer film, for example, a Ni film, a stacked film of a Pd film and an Au film, a stacked film of a Ni film and an Au film, a stacked film of an Ag film, a Pd film, and an AuAg alloy film may be used. The surface treatment layer is preferably composed of a plating layer. In short, the surface treatment layer is preferably formed by electroplating, but is not limited to being formed by electroplating.

The electrically insulating layer 22 can be formed on one surface 21a1 of the metal plate 21, and a hole portion 24 in which a central portion of one surface 21a1 of the metal plate 21 is exposed can be formed. The opening shape of the hole portion 24 is a rectangle. The shape of the opening of the hole portion 24 is not particularly limited.

As the material of the second conductor layer 23, for example, copper, phosphor bronze, a copper alloy, a nickel alloy, aluminum, an aluminum alloy or the like can be used. As the copper alloy, for example, a 42 alloy or the like can be used. The second conductor layer 23 can be formed, for example, by a metal foil, a metal film, or the like. The second conductor layer 23 preferably has a Cu layer, a Ni layer and an Au layer stacked structure, and the outermost surface side is an Au layer.

The electrically insulating layer 22 and each of the second conductor layers 23 can be formed, for example, by a printed wiring board. The electrical insulating layer 22 can be composed of an insulating base material of a printed wiring board, and a fixed adhesive sheet in which the insulating base material and the metal plate 21 are fixedly adhered. As the insulating substrate, for example, a polyimide film, a phenol paper substrate, a glass epoxy substrate, or the like can be used. As the fixing adhesive sheet, for example, a polyolefin-based fixing adhesive sheet can be used.

The substrate 20 is supported, and the metal plate 21, the electrically insulating layer 22, and each of the second conductor layers 23 may be formed by a metal base printed wiring board. At this time, in the support substrate 20, the metal plate 21 of the support substrate 20 can be formed by printing the metal plate of the wiring board with a metal base. Further, in the support substrate 20, the insulating layer of the wiring board can be printed on the metal substrate to form the electrically insulating layer 22 of the support substrate 20. Further, in the support substrate 20, each of the second conductor layers 23 of the support substrate 20 can be formed by printing a copper foil of the wiring board with a metal base.

The support substrate 20 has a protective layer 26 covering each of the second conductor layers 23 and a portion where the second conductor layers 23 are not formed in the electrical insulating layer 22 (see FIG. 1A). The protective layer 26 may be, for example, a white-based resist layer. As the material of the resist layer, for example, a white resist composed of a resin containing a white pigment such as barium sulfate (BaSO ₄ ) or titania (TiO ₂ ) (for example, a neon resin) can be used.

The protective layer 26 is patterned in such a manner that the first terminal portion 23a and the second terminal portion 23b of the second conductor layer 23 are exposed in the vicinity of the hole portion 24 of the electrically insulating layer 22.

In the ultraviolet light-emitting device 1, all of the ultraviolet LED chips 3 are mounted on the metal plate 21 through one sub-carrier member 13. Thereby, in the ultraviolet light-emitting device 1, the heat conduction path generated by each of the ultraviolet LED chips 3 forms a conduction path which is conducted by the sub-carrier member 13 and the metal plate 21 without being transmitted through the electrically insulating layer 22. Therefore, the ultraviolet light-emitting device 1 can improve heat dissipation. Thereby, the ultraviolet light-emitting device 1 can achieve the purpose of improving the output (light output).

The base material 13a of the sub-carrier member 13 is formed in a plate shape. The base material 13a has a rectangular shape in plan view, but is not limited thereto. For example, the base material 13a may have a shape such as a circular shape or a polygonal shape other than a rectangular shape. The planar dimensions of the sub-carrier member 13 are preferably set to a plurality of ultraviolet LED wafers 3 and are larger than the sum of the plurality of ultraviolet LED wafers 3. The plane size of the sub-carrier member 13 is set to 4.3 mm × 3 mm, but this is merely an example and is not particularly limited. The material of the substrate 13a is preferably a material having a high thermal conductivity and a linear expansion coefficient which is a value between the linear expansion coefficient of the metal plate 21 and the linear expansion coefficient of the ultraviolet LED wafer 3. Thereby, the ultraviolet light-emitting device 1 can prevent cracks from occurring at the joint portion between the ultraviolet LED chip 3 and the sub-carrier member 13 due to thermal stress. Further, for the joint portion of the ultraviolet LED wafer 3 and the sub-carrier member 13, for example, a bump can be used. The material of the substrate 13a is AlN.

The first conductor layer 13b of the sub-carrier member 13 is formed into a predetermined pattern so that the plurality of ultraviolet LED chips 3 can be connected in series and in parallel. The first conductor layer 13b is patterned such that a plurality of ultraviolet LED chips 3 can be arranged at substantially equal intervals on the circumference of one imaginary circle. The pattern of the first conductor layer 13b is not particularly limited.

The first conductor layer 13b may be configured such that a plurality of ultraviolet LED chips 3 are connected in series or may be connected in parallel.

The sub-carrier member 13 can be joined to the metal plate 21 through a first joint portion (not shown). The material of the first bonding portion is, for example, a lead-free solder such as AuSn or SnAgCu. When the material of the first joining portion is AuSn, it is necessary to preliminarily form a metal layer made of Au or Ag on the joining surface of one surface 21a1 of the metal plate 21. The first joint portion may be formed of a conductive paste. As the conductive paste, for example, silver glue, gold glue, copper glue or the like can be used.

The thickness of the sub-carrier member 13 is preferably set such that the surface of the first conductor layer 13b is farther from the metal plate 21 than the surface of the protective layer 26. Then, the ultraviolet light-emitting device 1 can prevent light emitted from the ultraviolet LED chip 3 to the both sides from being absorbed by the electrically insulating layer 22 through the inner peripheral surface of the hole portion 24 of the electrically insulating layer 22.

The thickness dimension of the sub-carrier member 13 is set to about 0.3 mm, but is not particularly limited. Among them, in the ultraviolet light-emitting device 1, since the thickness of the sub-carrier member 13 is larger as the thermal resistance in the thickness direction is larger, it is not preferable to set it too large.

As the material of the first conductor layer 13b, for example, Au, Ag, or the like can be used. In the ultraviolet light-emitting device 1, when the ultraviolet LED chip 3 is electrically connected through the bumps, the material of the first conductor layer 13b is preferably the same as that of the bump. When the material of the bump is Au, the material of the first conductor layer 13b is also preferably Au. The first conductor layer 13b is not limited to a single layer film, and may be a multilayer film. In this case, the outermost layer is preferably formed of the same material as the material of the bump.

In the ultraviolet light-emitting device 1, when the ultraviolet LED chip 3 is provided with the first electrode on one surface side in the thickness direction and the second electrode is provided on the other surface side, the ultraviolet LED wafer 3 and the sub-carrier member 13 can be, for example, It is bonded by a solder such as SnPb, AuSn, or SnAgCu or a conductive paste such as silver paste. The bonding of the ultraviolet LED chip 3 and the first conductor layer 13b of the sub-carrier member 13 is preferably performed by using a lead-free solder such as AuSn or SnAgCu. In this case, the first conductor layer 13b is preferably made of a metal layer such as an Au layer or an Ag layer. The first conductor layer 13b may be formed by, for example, a vapor deposition method, a sputtering method, or a CVD (Chemical Vapor Deposition) method.

In the ultraviolet light-emitting device 1, for example, when one side of the ultraviolet LED chip 3 is in the thickness direction When the first electrode is provided and the second electrode is provided on the other surface side, the sub-carrier member 13 has a tendency to relax the stress acting on the ultraviolet LED wafer 3 due to the difference in linear expansion ratio between the ultraviolet LED chip 3 and the metal plate 21. Features. The sub-carrier member 13 has a heat conduction function of transferring the heat generated by the ultraviolet LED wafer 3 to a wider range of the wafer size of the ultraviolet LED wafer 3 than the ultraviolet LED wafer 3, in addition to the function of alleviating the stress. Therefore, the ultraviolet light-emitting device 1 can efficiently dissipate heat generated by the ultraviolet LED wafer 3 through the sub-carrier member 13 and the metal plate 21.

The material of the substrate 13a is not limited to AlN, and for example, Si, CuW, composite SiC, or the like can also be used. When the material of the substrate 13a is made of a material such as Si or CuW which is not an insulator, an insulating film is provided on the surface of the base material composed of the material of the substrate 13a, and the first conductor layer is formed on the insulating film. 13b can form a predetermined pattern.

The sub-carrier member 13 may form a reflection film that reflects the ultraviolet rays emitted from the ultraviolet LED wafer 3 in a region where the first conductor layer 13b is not formed on the surface of the substrate 13a. Thereby, the sub-carrier member 13 can prevent the ultraviolet rays radiated from the side surface of the ultraviolet LED chip 3 from being absorbed by the sub-carrier member 13, thereby improving the light extraction efficiency to the outside. Here, the reflective film of the sub-carrier member 13 may be composed of, for example, a stacked film of a Ni film and an Al film.

The sub-carrier member 13 may be provided with an insulating layer made of an electrically insulating material in a region where the frame 4 may come into contact. Thereby, when the frame 3 is formed of a material such as metal, the first conductor layer 13b can be electrically insulated from the frame 4. As the electrical insulating material of the insulating layer, for example, a material such as tantalum oxide can be used.

In the ultraviolet light-emitting device 1, the hole portion 29 penetrating the mounting substrate 2 in the thickness direction is preferably provided on the mounting substrate 2 so as to be attachable to another member such as a circuit board. The opening shape of the hole portion 29 is a circular shape. In the ultraviolet light-emitting device 1, the mounting substrate 2 has a rectangular shape in plan view, and the second terminal portion 23b is provided in the vicinity of the two corner portions facing each other among the four corner portions of the mounting substrate 2, and the remaining portions are provided. A hole portion 29 is provided in the vicinity of the two corner portions. Thereby, the ultraviolet light-emitting device 1 can be attached to another member such as a circuit board by a member such as a bolt. The bolt is as long as the outer diameter of the head portion is larger than the inner diameter of the hole portion 29, and the outer diameter of the shaft portion is smaller than the inner diameter of the hole portion 29, that is, can. For bolts, metal bolts or resin bolts can be used.

Since the two second terminal portions 23b and the two hole portions 29 are arranged as described above in the ultraviolet light-emitting device 1, it is possible to prevent the stress applied to the second joint portion of the second terminal portion 23b and the electric wire or the bolt. The stress or the like causes problems such as warpage of the mounting substrate 2.

The casing 4 is disposed on the first surface 2a1 side of the mounting substrate 2. The casing 4 and the mounting substrate 2 are joined to each other through a third joint portion (not shown). As the material of the third joint portion, for example, a material such as an epoxy resin can be used.

The frame 4 is formed in a frame shape in which the opening area is gradually increased from the mounting substrate 2. The housing 4 constitutes a reflecting portion that reflects ultraviolet rays emitted from the ultraviolet LED chip 3 to both sides to the window member 5 side.

The material of the frame 4 is made of aluminum. The reflectance of the reflecting surface formed by the inner side surface 4a of the casing 4 is, for example, about 97% for ultraviolet rays of 265 nm. The angle formed by the surface of the casing 4 on the side of the mounting substrate 2 and the inner side surface 4a is set to 55°, but this is merely an example and is not particularly limited. The material of the frame 4 is not limited to aluminum, and may be, for example, a resin such as PBT. In this case, the frame 4 is preferably provided with a reflective film made of a metal such as aluminum on the inner surface of the frame-shaped resin molded article. The frame 4 may have a structure integrally formed with the mounting substrate 2. Further, the casing 4 is not limited to necessarily forming the reflecting portion.

The outer peripheral shape of the window member 5 is rectangular, but is not particularly limited. The window member 5 is disposed to cover the frame 4 and the plurality of ultraviolet LED chips 3. Here, the window member 5 is joined to the opposite side surface of the casing 4 on the side of the mounting substrate 2.

The light transmittance of the ultraviolet ray emitted from the window material 5 to the ultraviolet LED chip 3 is preferably 70% or more, more preferably 80% or more. As the material of the window material 5, for example, quartz glass or borosilicate glass having a light transmittance of ultraviolet rays emitted from the ultraviolet LED chip 3 of 80% or more is preferably used. When the material of the window material 5 is borosilicate glass, for example, a product of No. 8337B manufactured by SCHOTT Co., Ltd., or the like can be used. Thereby, in the ultraviolet light-emitting device 1, the light transmittance of the ultraviolet ray emitted from the window member 5 to the ultraviolet LED chip 3 can be made 80% or more.

The window material 5 is formed into a flat shape, but is not limited thereto. For example, the window material 5 may have a lenticular shape.

Hereinafter, the light distribution characteristics of the point light source will be described first, and then the light distribution characteristics of the ultraviolet light-emitting device 1 will be described.

Fig. 6A is an explanatory diagram showing the light distribution characteristics of the light source 10 of the point light source in terms of polar coordinates. Fig. 6B is an explanatory diagram showing the light distribution characteristics of the light source 10 in a rectangular coordinate.

When the light distribution of the radiation intensity of the light source 10 is set to I ₀ in the normal direction of the center point of the light extraction surface of the light source 10, the angle with respect to the normal direction is set to the radiation angle. emitted light intensity [theta], [theta] and the angle of emission direction is I _θ, then ^{_{I θ = I 0 cos n θ}} . Where n is a real number of 1 or more. Accordingly, the radiated radiation intensity I of the light intensity I _{[theta] 0,} normalization / I distribution of the light distribution ₀ cos ⁿ θ.

In each of FIGS. 6A and 6B, A ₀₁ , A ₀₂ , A _{03 ,} and A ₀₄ , the normalized radiation light intensities I _θ /I ₀ are cos θ, cos ² θ, cos ³ θ, and cos ⁴ θ, respectively. Light distribution characteristics. Fig. 7 is an explanatory diagram of a light distribution of the point light source 10 on the planar illuminated surface 7. In Fig. 7, A ₁₁ , A ₁₂ , A _{13 ,} and A ₁₄ are illuminance distributions on the illuminated surface 7 when the light distribution characteristics are A ₀₁ , A ₀₂ , A _{03 ,} and A ₀₄ , respectively.

In addition, when the irradiated material is irradiated with ultraviolet rays for the purpose of disinfection of bacteria or the like, the amount of ultraviolet rays necessary for disinfection of bacteria varies depending on the type of bacteria or growth conditions, and the irradiation intensity [W/cm ² ] can be used. × irradiation time (sec) is indicated. Here, the inventors of the present invention thought that if the irradiation time is the same, the irradiation intensity of the ultraviolet ray in the irradiation region can be made substantially larger, and it is not necessary to enhance the irradiation intensity in the vicinity of the center of the irradiation region. Then, the inventors of the present invention considered that when the planar irradiation target surface is irradiated with ultraviolet rays, excess energy is consumed in the central portion of the light distribution, that is, in the range where the absolute value of the radiation angle θ is small.

Thus, the inventor of the present invention thought of flattening the central portion of the light distribution as shown in FIG. 8A. (flat) light distribution characteristics. The light distribution of FIG. 8A and FIG. 8B is a light distribution when the irradiated surface irradiated in the range of 1/2 beam angle is irradiated with uniform radiation light intensity in the light distribution of FIGS. 6A and 6B. Here, the 1/2 beam angle refers to an angle twice the angle formed by the direction in which the intensity of the radiation light becomes 1/2 of the maximum value and the optical axis.

FIG. 8A is an explanatory diagram showing the target light distribution characteristics of the ultraviolet light-emitting device 1 in terms of polar coordinates. Fig. 8B is an explanatory diagram showing the target light distribution characteristics of the ultraviolet light-emitting device 1 in a rectangular coordinate.

In each of FIGS. 8A and 8B, A ₂₁ , A ₂₂ , A _{23 ,} and A ₂₄ are in the case where the light distribution characteristics are cos θ, cos ² θ, cos ³ θ, and cos ⁴ θ, respectively. The light distribution characteristics when the irradiated surface irradiated in the range of the beam angle is irradiated with uniform radiation light intensity. Fig. 9 is an explanatory diagram of a target light distribution of the ultraviolet light-emitting device 1 on the illuminated surface 7. In Fig. 9, A ₃₁ , A ₃₂ , A _{33 ,} and A ₃₄ are illuminance distributions on the illuminated surface 7 when the light distribution characteristics are A ₂₁ , A ₂₂ , A _{23 ,} and A ₂₄ , respectively. The light distribution of Fig. 9 is a light distribution of a flat portion on the surface 7 to be illuminated.

Then, in the ultraviolet light-emitting device 1, the radiation angle dependence of the radiation light intensity I _θ is taken as the reference of the same output with cos ⁿ θ (n is a real number of 1 or more), and is smaller than the cos ⁿ θ in the first limited range. In the second limited range, it is larger than cos ⁿ θ, and a plurality of ultraviolet LED chips 3 are arranged in this manner. Thereby, the ultraviolet light-emitting device 1 can ensure the illuminance necessary for the planar illuminated surface 7 (see FIG. 4) and achieve uniformity of illumination. In FIG. 5A, the first limited range is set to -19° < θ < 19°, which is an angular range that is the same as the 1/2 beam angle.

FIG. 10 is a practical example of the light distribution characteristics indicated by the polar coordinates of the embodiment of the ultraviolet light-emitting device 1. In Fig. 10, Ax indicates that when the X-axis and the Y-axis orthogonal to the optical axis are defined, the light distribution characteristics on the plane including the optical axis and the X-axis, and Ay are included in the optical axis. Light distribution characteristics on the plane with the Y axis.

Fig. 11 is a view showing an actual measurement example of the light distribution characteristics indicated by the rectangular coordinates of the embodiment of the ultraviolet light-emitting device 1. In Fig. 11, the measured light distribution characteristics on the plane including the optical axis and the X-axis are indicated by solid lines, and the alignment characteristics of the imaginary cos ² θ on the plane including the optical axis and the X-axis are a little chain. Line representation.

Fig. 12 is a diagram in which the output of the virtual cos ² θ alignment characteristic is normalized to the same output as the actual measurement example with respect to the light distribution characteristics of Fig. 11 . Fig. 12 is an explanatory view of the light distribution characteristics of this embodiment of the ultraviolet light-emitting device 1. In Fig. 12, the solid line indicates the measured light distribution characteristics, and the one-point chain line indicates the normalized alignment characteristic of cos ² θ. Seen from FIG. 12, 1 and A ₂ can be obtained the same light distribution characteristic of the ultraviolet light-emitting device of FIG. 5A. Therefore, the ultraviolet light-emitting device 1 can ensure the necessary illuminance on the planar illuminated surface 7, and at the same time achieve the purpose of uniformizing the illuminance.

Fig. 13 is an illuminance distribution diagram of the ultraviolet ray emitting device 1 on the illuminated surface 7. This illuminance distribution map is a simulation result of the illuminance on the illuminated surface 7. Fig. 13A shows the distribution of irradiance on a right angle plane. Fig. 13B shows the distribution of the irradiance on the X-axis. Fig. 13C shows the distribution of irradiance on the Y-axis.

It can also be inferred from Fig. 13 that the ultraviolet light-emitting device 1 can ensure the illuminance necessary for the planar illuminated surface 7 and at the same time achieve the purpose of uniformizing the illuminance.

In the ultraviolet light-emitting device 1, the shape of the frame 4 and the like are limited in consideration of the requirements for miniaturization and low height. Therefore, in the ultraviolet light-emitting device 1, as shown in FIG. 3, when the height dimension of the frame 4 is set to H2, the height dimension of the ultraviolet LED chip 3 is set to H1, and the width of the mounting area of the plurality of ultraviolet LED chips 3 is set. When W1 is set and the maximum inner diameter of the casing 4 is W2, it is considered that the condition of H1 < H2 ≦ W1/2 and W2 ≦ 2 × W1 is satisfied. At this time, the ultraviolet light-emitting device 1 cannot consider a group of the plurality of ultraviolet LED chips 3 as a point light source. Therefore, in the ultraviolet light-emitting device 1, it is difficult to obtain a desired light distribution only by the shape design of the frame 4 constituting the reflection portion, and the frame 4 has only a function of finely adjusting the light distribution. However, in the ultraviolet light-emitting device 1 of the present embodiment, the plurality of ultraviolet LED chips 3 are avoided in the region 2a surrounded by the frame 4 in a plan view of the first surface 2a1 of the mounting substrate 2 to avoid the region 2a. The center 2aa is arranged in such a manner as to surround the center 2aa. Therefore, in the ultraviolet light-emitting device 1 of the present embodiment, the illuminance necessary for the planar illuminated surface 7 can be ensured by the group arrangement of the plurality of ultraviolet LED chips 3, and the illuminance can be uniformized. . The ultraviolet light-emitting device 1 can be miniaturized and reduced in height. Reduce material costs, thereby reducing costs, or assembly in a narrow space in sanitary fixtures. Further, the sanitary appliance is, for example, a sterilizer, a water purifier, a purifier, or the like.

When the ultraviolet light-emitting device 1 considers one of cos ² θ, cos ³ θ, and cos ⁴ θ as a reference for the same output, the frame 4 preferably constitutes a reflecting portion. When the ultraviolet light-emitting device 1 uses cos θ as a reference for the same output, the frame 4 may constitute a reflection portion, and may not constitute a reflection portion. Further, when the ultraviolet light-emitting device 1 regards one of cos ³ θ and cos ⁴ θ as a reference for the same output, the window member 5 preferably has a plano-convex lens shape. When the ultraviolet light-emitting device 1 uses one of cos θ and cos ² θ as a reference for the same output, the window material 5 may have a plano-convex lens shape, and may have a plate shape and may have a plate shape.

Fig. 14 is a main part explanatory view showing a first modified example of the ultraviolet light-emitting device 1 according to the embodiment.

In the ultraviolet light-emitting device 1, as shown in the first modified example of FIG. 14, the window member 5 may have a plano-convex aspherical lens portion 5a and a convex portion that protrudes outward from the outer peripheral portion of the aspherical lens portion 5a over the entire circumference. The structure of the edge 5b.

The aspherical lens portion 5a is optically designed to control the light distribution of the ultraviolet rays emitted from the ultraviolet LED wafer 3. The solid line with an arrow in FIG. 14 schematically shows an example of the direction in which the ultraviolet light emitted from the ultraviolet LED chip 3 is proceeding.

The flange 5b is a portion for joining the window member 5 and the frame body 4. The flange 5b is preferably planar on both sides in the thickness direction. In the ultraviolet light-emitting device 1, the above-described borosilicate glass is used as the material of the window member 5, whereby the window member 5 can be formed by molding. The window member 5 is joined to the frame 4 by a flange 5b. In the window material 5, the first lens surface 5aa of the aspherical lens portion 5a on the side close to the mounting substrate 2 is formed of a convex curved surface, and the second lens surface 5ab on the side away from the mounting substrate 2 is formed of a flat surface. The convex curved surface constituting the first lens surface 5a changes its curvature continuity. The aspherical lens portion 5a of the window member 5 is preferably disposed inside the frame 4 in plan view.

The window member 5 has a plano-convex aspherical lens portion 5a, which is constructed by a hemispherical spherical lens In the case of the case, the absorption loss can be further reduced.

Fig. 15 is a illuminance distribution diagram of the first modified embodiment of the ultraviolet light-emitting device 1 on the illuminated surface. This illuminance distribution map is a simulation result of the illuminance on the illuminated surface 7. Fig. 15A shows the distribution of irradiance on the XY plane. Fig. 15B shows the distribution of the irradiance on the X-axis. Fig. 15C shows the distribution of irradiance on the Y-axis.

It can also be inferred from Fig. 15 that the ultraviolet light-emitting device 1 can ensure the illuminance necessary for the planar illuminated surface 7 and at the same time achieve the purpose of uniformizing the illuminance.

Further, in the ultraviolet light-emitting device 1, as in the second modified example shown in FIG. 16, the first lens surface 5aa on the side close to the mounting substrate 2 among the aspherical lens portions 5a of the window member 5 may be planar. The second lens surface 5ab on the side away from the mounting substrate 2 is formed of a convex curved surface. The convex curved surface constituting the second lens surface 5ab changes its curvature continuity. The solid line with an arrow in Fig. 16 schematically shows an example of the direction in which the ultraviolet light emitted from the ultraviolet LED chip 3 is proceeding.

In the ultraviolet light-emitting device 1 of the first modified example and the ultraviolet light-emitting device 1 of the second modified example, the ultraviolet light-emitting device 1 of the first modified example can reduce the ultraviolet rays passing through the flange 5b, thereby preventing the efficiency from being lowered. Moreover, the light distribution control becomes easier.

Further, each of the drawings described in the above embodiments is a schematic view, and the ratio of the size or thickness of each constituent element does not necessarily reflect the actual component size ratio.

1‧‧‧UV illuminating device

2‧‧‧Installation substrate

2a‧‧‧Area

2a1‧‧‧1st

2aa‧‧‧ Center

3‧‧‧UV LED chip

4‧‧‧ frame

5‧‧‧ Window materials

13‧‧‧Sub-assembly components

13b‧‧‧1st conductor layer

13bb‧‧‧Wiring Department

17‧‧‧ lead

20‧‧‧Support substrate

21a1‧‧‧ surface

23‧‧‧2nd conductor layer

23a‧‧‧1st terminal part

23b‧‧‧2nd terminal section

24‧‧‧ Hole Department

26‧‧‧Protective layer

29‧‧‧ Hole Department

Claims (3)

An ultraviolet light emitting device, comprising: a mounting substrate; a plurality of ultraviolet LED chips mounted on a surface side of the mounting substrate; and a frame body on the one surface side of the mounting substrate to surround the plurality of ultraviolet LED chips And a window material disposed on the surface side of the mounting substrate to cover the frame and the plurality of ultraviolet LED chips, wherein ultraviolet rays from each of the ultraviolet LED chips are transparent to the window material; The radiation angle of the optical axis is θ , the radiation intensity of the radiation angle θ direction is I _θ , and the range of the radiation angle θ is divided into the first range including 0° between -90° and 90°. When the limited range and the second limited range in which the absolute value is larger than the numerical value in the first limited range, the radiation angle dependence of the radiation light intensity I _{θ is} the same output as cos ⁿ θ (n is a real number of 1 or more) a reference, the plurality of ultraviolet LED chips are arranged in a region surrounded by the frame in a plan view of the surface of the mounting substrate, avoiding a center of the region and surrounding the center, and emitting a light intensity I _θ radiation Degree of dependence on the first defined range is smaller than cos ⁿ θ, while in the second range defined larger than cos ⁿ θ. The ultraviolet light-emitting device according to claim 1, wherein the frame is a reflection portion that reflects ultraviolet rays emitted from the ultraviolet LED chips toward both sides toward the window member side. The ultraviolet light-emitting device of claim 1, wherein the window material comprises: a plano-convex aspherical lens portion that controls a light distribution of ultraviolet rays emitted by the ultraviolet LED chip; and a flange from which the The outer peripheral portion of the spherical lens portion protrudes outwardly over the entire circumference; the flange is joined to the frame; and the first lens surface on one side of the mounting substrate is formed by a convex curved surface away from the other side of the mounting substrate The second lens surface is formed by a flat surface.