Light-emitting element and light irradiation device

Abstract

To provide an electron beam excitation type light-emitting element that can be easily mounted on a substrate such as a printed board, and a light irradiation device including the light-emitting element.SOLUTION: A light-emitting element 10 includes an electron beam source 11, and a light-emitting unit 21 including a light-emitting layer 21L excited by an electron beam of the electron beam source 11. The electron beam source 11 is mounted on a board 31, and an outline part 51 that surrounds the electron beam source 11 from above is disposed on an upper surface 31A of the substrate 31. The light-emitting unit 21 is disposed over the outline part 51. The space surrounded by the substrate 31, the outline part 51, and the light-emitting unit 21 is vacuum. The light-emitting unit 21 includes an anode electrode 41 to which the high voltage for accelerating the electron beam is applied. A cathode terminal TC and a gate terminal TG that electrically connect to the electron beam source 11, and an anode terminal TA that electrically connects to the anode electrode 41 are disposed planarly on a lower surface 31 of the substrate 31 so that the substrate 31 can be mounted planarly.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a light-emitting element and a light irradiation device. [Background technology]

[0002] Development of electron beam excited light emitting devices comprising an electron beam source and a light emitting layer excited by the electron beam of the electron beam source is underway (e.g., Patent Documents 1 to 3). This type of light emitting device is expected to serve as a light source of deep ultraviolet light suitable for disinfection, sterilization, sterilization, surface modification, etc. Patent Document 1 proposes a configuration in which, with the aim of combining an electron beam source and a light emitting layer excited by the electron beam of the electron beam source into an element or modularization, a glass plate is placed on an electron emitting element, and a gold vapor deposition surface and a hexagonal boron nitride thin film are laminated on the glass plate, thereby forming a cathode attached to the back surface of the substrate of the electron emitting element and a Ti / Au surface formed on the underside of the hexagonal boron nitride thin film as an anode. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-79873 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-46415 [Patent Document 3] Japanese Patent Publication No. 2023-55415 Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, it is desirable to develop an electron beam excited light emitting element that can be easily mounted on a substrate such as a printed circuit board, in the same way as general semiconductor components. However, none of the techniques described in Patent Documents 1 to 3 disclose mounting on a printed circuit board, etc. For example, the technique described in Patent Document 1 discloses applying a voltage to an anode electrode attached to the back surface of a light-emitting layer, an electron beam emitting substrate attached to the light-emitting layer via an insulating spacer, and a cathode electrode attached to the back surface of the electron beam emitting substrate, but does not disclose how to mount on a printed circuit board. Therefore, an object of the present disclosure is to provide an electron beam excited light emitting element that can be easily mounted on a mounting board such as a printed circuit board, and a light irradiation device including the light emitting element. [Means for solving the problem]

[0005] In order to achieve the above object, there is provided a light-emitting element comprising an electron beam source and a light-emitting layer excited by electron beams from the electron beam source, the light-emitting element comprising: a substrate having an upper surface and a lower surface, on the upper surface of which the electron beam source is mounted; an outer shell that surrounds the electron beam source from above and has a vacuum interior; and a light-emitting section that is arranged above the outer shell and has the light-emitting layer L, the light-emitting section having an anode electrode to which a high voltage for accelerating the electron beam is applied, and a cathode terminal and a gate terminal that are electrically connected to the electron beam source, and an anode terminal that is electrically connected to the anode electrode, are arranged on the lower surface of the substrate in a planar manner so that the substrate can be surface-mounted. The present invention also provides a light irradiation device for industrial use that includes a printed circuit board on which the light emitting element is mounted, and that irradiates an object with light from the light emitting element. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide an electron beam excited light emitting element that can be easily mounted on a mounting board such as a printed circuit board, and a light irradiation device including the light emitting element. [Brief explanation of the drawings]

[0007] [Figure 1] (A) shows the wiring structure of the light-emitting element, and (B) shows the light-emitting principle. [Figure 2] FIG. 2 is a diagram schematically illustrating a cross-sectional structure of a light-emitting element. [Figure 3] FIG. 2 is a diagram showing a conductive structure between an electron beam source and a substrate. [Figure 4] 10A and 10B are diagrams showing the conductive structure between the light-emitting part and the outer casing, and the conductive structure between the outer casing and the substrate. [Figure 5] 10A and 10B are diagrams illustrating modified examples of the outer pattern layer. [Figure 6] FIG. 1A is a perspective view of a light emitting element according to a first embodiment, and FIG. 1B is an exploded perspective view of the light emitting element according to the first embodiment. [Figure 7] FIG. 2 is a diagram showing a substrate of the light emitting element according to the first embodiment. [Figure 8] 1(A) to 1(D) are diagrams showing a number of modes in which a light emitting element is mounted on a mounting substrate. [Figure 9] (A) shows the outer casing of the light-emitting element according to the second embodiment, (B) shows the cross-sectional structure of the light-emitting element 10 according to the second embodiment, and (C) shows the cross-sectional structure of a light-emitting element according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 shows the basic structure of a light-emitting element 10 according to this embodiment, with Fig. 1(A) showing the wiring structure of the light-emitting element 10 and Fig. 1(B) showing the light-emitting principle. Fig. 2 is a diagram schematically showing the cross-sectional structure of the light-emitting element 10. The light-emitting element 10 of this embodiment has a configuration in which an electron beam source 11, a light-emitting section 21 having a light-emitting layer 21L excited by electron beams from the electron beam source 11, a substrate 31 (FIG. 2) on which the electron beam source 11 is mounted, and an anode electrode 41 to which a high voltage is applied are integrated into a device and packaged. Therefore, the light-emitting element 10 can be referred to as an electron-beam-excited light-emitting element, an electron-beam-excited light-emitting element package, or the like. Since the anode electrode 41 is provided in the light-emitting layer 21L, the anode electrode 41 will be described as being provided in the light-emitting section 21.

[0009] 1(A), the electron beam source 11 has a MIM (Metal / Insulator / Metal) structure in which an insulator (e.g., an insulating film) is sandwiched between an upper electrode 11A and a lower electrode 11B, or a MIS (Metal / Insulator / Semiconductor) structure in which an oxide (e.g., an oxide film) is sandwiched between the upper electrode 11A and the lower electrode 11B, and is formed into a planar electron beam source 11. In FIG. 1(A), the portion (insulator / oxide) between the upper electrode 11A and the lower electrode 11B is indicated by the reference numeral 11C.

[0010] The lower electrode 11B corresponds to a cathode electrode, and the upper electrode 11A corresponds to a gate electrode having a positive potential relative to the cathode electrode. By applying a predetermined voltage Va between the upper electrode 11A and the lower electrode 11B, a strong electric field is created in the portion 11C, causing electrons to tunnel. Of these electrons, those with energy exceeding the work function of the upper electrode 11A are emitted into vacuum. The voltage Va is, for example, 10 to 30 V.

[0011] It is preferable to use graphene for the upper electrode 11A in order to suppress scattering of electrons by the upper electrode 11A. For example, graphene can be formed on an insulating film by chemical vapor deposition (CVD). Employing a layered structure (which can be called a GOS structure) consisting of graphene / oxide film / silicon (Graphene / Oxide / Semiconductor) for the electron beam source 11 can improve electron emission efficiency.

[0012] The anode electrode 41 faces the upper electrode 11A of the electron beam source 11, and accelerates the electron beam generated by the electron beam source 11 in a vacuum space (acceleration space) by applying an acceleration voltage Vb to the anode electrode 41. The anode electrode 41 is also called an extraction electrode that accelerates the electron beam. The acceleration voltage Vb is a high voltage, for example, 5 to 15 kV. As shown in FIG. 1(B), the light-emitting unit 21 has a structure in which a first thin film functioning as the light-emitting layer 21L and a second thin film functioning as the anode electrode 41 are laminated on the lower surface of a transparent substrate 21T. The first thin film is a light-emitting layer that emits deep ultraviolet light when irradiated with an electron beam, and the light from the light-emitting layer passes through the transparent substrate 21T and is emitted to the outside. Suitable materials for the transparent substrate 21T are MgF2 (magnesium fluoride), Al2O3 (sapphire), CaF2 (calcium fluoride), SiO2 (synthetic quartz / fused silica), and LiF (lithium fluoride), which are known to be highly transparent to deep ultraviolet light.

[0013] In this embodiment, the first thin film (light-emitting layer 21L) is made of a thin film of magnesium zinc oxide (MgZnO) or hexagonal boron nitride (hBN), which emits deep ultraviolet light having a peak wavelength in the shorter wavelength range of ultraviolet light. The second thin film (anode electrode 41) is made of an aluminum (Al) evaporated film formed with a slit of a predetermined width, and an electron beam passing through the slit irradiates the first thin film.

[0014] With the above configuration, the electron beam source 11 and the light-emitting unit 21 can be easily manufactured using semiconductor microfabrication technology, and can be easily miniaturized. Semiconductor microfabrication technology includes photolithography, etching, thin film formation, etc. Furthermore, since the device emits deep ultraviolet light, it is suitable for disinfection, sterilization, sterilization, surface modification, and other applications.

[0015] The material and structure of each part of the electron beam source 11 may be changed as appropriate within the scope of feasible manufacturing methods using semiconductor microfabrication techniques. For example, the material of the first thin film may be changed as appropriate to irradiate desired light such as ultraviolet light, or Cs may be added to the upper electrode 11A to improve electron emission efficiency. Furthermore, although the light emitting layer 21L is formed as a thin film in the above example, it is not limited to a thin film, and the light emitting layer 21L may be directly attached to the transparent substrate 21T.

[0016] 2, the electron beam source 11 of the light-emitting element 10 is mounted on the upper surface 31A of a substrate 31 made of a flat ceramic substrate. The light-emitting element 10 also has an outer casing 51 that surrounds the electron beam source 11 from above. The outer casing 51 has an opening 51K that opens in the vertical direction, and the opening 51K is closed by the light-emitting element 21. The space surrounded by the outer casing 51, the light-emitting element 21, and the substrate 31 is a vacuum.

[0017] FIG. 3 is a diagram showing the conduction structure between the electron beam source 11 and the substrate 31. As shown in FIG. 3, the lower electrode 11B of the electron beam source 11 is joined to the upper surface 31A of the substrate 31 with a metal joining material MB1 made of a solder material or a metal brazing material. More specifically, an electrode layer M1 (hereinafter referred to as the lower electrode layer M1) is provided on the lower surface of the lower electrode 11B, and a pattern layer M2 (hereinafter referred to as the substrate upper surface cathode pattern layer M2) that forms part of the conductive pattern on the upper surface of the substrate 31 is provided on the upper surface 31A of the substrate 31, and these lower electrode layer M1 and substrate upper surface cathode pattern layer M2 are joined together with the metal joining material MB1. This electrically and physically connects the lower electrode 11B and the substrate 31.

[0018] The lower electrode layer M1, the substrate upper surface cathode pattern layer M2, and each of the pattern layers M4, M6 to M8 described below are formed by metallizing the base material surface (e.g., the surface of a non-metal such as ceramic) of the substrate 31, and are made of, for example, an alloy of Ni (nickel) and an active metal such as Ti (titanium) or Cr (chromium). The electrode layer and pattern layers M1 to M8 may also be made of other metal materials (conductive members). Each of the electrode layers and pattern layers M1 to M8 can be formed using semiconductor microfabrication technology.

[0019] The upper electrode 11A of the electron beam source 11 is electrically connected to the upper surface 31A of the substrate 31 using known wire bonding. More specifically, an electrode layer M3 (hereinafter referred to as the upper electrode layer M3) is provided on a part of the upper surface of the upper electrode 11A, and a pattern layer M4 (hereinafter referred to as the substrate upper surface gate pattern layer M4) that forms a part of the conductive pattern on the upper surface of the substrate 31 is provided on the upper surface 31A of the substrate 31, and these electrode layer M3 and pattern layer M4 are connected to each other by a metal wire W1 (conductive member). Note that connection may be made by a method other than wire bonding.

[0020] A cathode terminal TC and a gate terminal TG, each made of an electrode layer constituting part of the conductive pattern on the underside of the substrate 31, are provided at a distance from each other on the underside 31B of the substrate 31. The cathode terminal TC is electrically connected to a substrate upper surface cathode pattern layer M2, which is electrically connected to the lower electrode 11B, by a via structure ST1, such as a through-hole via, penetrating the substrate 31. The gate terminal TG is electrically connected to a substrate upper surface gate pattern layer M4, which is electrically connected to the upper electrode 11A, by a via structure ST2, such as a through-hole via, penetrating the substrate 31.

[0021] FIG. 4 is a diagram showing the conductive structure between the light-emitting section 21 and the outer casing 51, and the conductive structure between the outer casing 51 and the substrate 31. As shown in FIG. 4, an electrode layer M5 (hereinafter referred to as bonding electrode layer M5) that functions as a buffer layer (adhesion layer) is provided on the lower surface of the second thin film that functions as the anode electrode 41, and a pattern layer M6 (hereinafter referred to as outer portion pattern layer M6) that is bonded to the bonding electrode layer M5 via a metal bonding material MB2 made of a solder material or a metal brazing material is provided on the outer portion 51. In the example of FIG. 4, the outer portion 51 is formed of an insulating material, and the outer portion pattern layer M6 made of a conductor is provided so as to be continuous across the upper surface, outer side surface, and lower surface of the outer portion 51. The anode electrode 41 and the outer portion 51 (outer portion pattern layer M6) are electrically and physically connected via these pattern layers and the metal bonding material MB2.

[0022] Here, the aluminum (AL) vapor deposition film comprising the second thin film (anode electrode 41) has a strong surface oxidation property, making soldering or brazing difficult. Therefore, in this configuration, a bonding electrode layer M5 containing at least one of Ti and Cr is provided on the surface of the second thin film, and this bonding electrode layer M5 is bonded to the outer pattern layer M6 via a metal bonding material MB2. This makes it easy to bond the AL vapor deposition film comprising the anode electrode 41 to the outer pattern layer M6 comprising the conductor of the outer portion 51.

[0023] The outer pattern layer M6 constituting the conductor of the outer casing 51 is joined to the upper surface 31A of the substrate 31 at a position corresponding to the lower surface of the outer casing 51 via a metal joining material MB3 made of solder or brazing metal. More specifically, a pattern layer M7 (hereinafter referred to as a substrate upper surface anode pattern layer M7) constituting part of the conductive pattern on the upper surface of the substrate 31 is provided on the upper surface 31A of the substrate 31, and these pattern layers M6, M7 are joined to each other via the metal joining material MB3. This electrically and physically connects the outer pattern layer M6 constituting the conductor of the outer casing 51 and the substrate 31.

[0024] An anode terminal TA is provided on the lower surface 31B of the substrate 31. The anode terminal TA is formed of a pattern layer that constitutes part of the conductive pattern on the lower surface of the substrate 31. The anode terminal TA is electrically connected to the outer pattern layer M6 that constitutes the conductor of the outer surface 51 by a via structure ST3, such as a through-hole via, that penetrates the substrate 31. In this way, the cathode terminal TC, the gate terminal TG, and the anode terminal TA are arranged in a planar manner with intervals between them on the lower surface 31B of the substrate 31, which enables easy mounting of the light emitting element 10 (light emitting element package) on a mounting substrate such as a printed circuit board 31. The positions of the anode terminal TA and the like can be appropriately set within the range of the lower surface 31B of the substrate 31. This makes it easier to ensure an insulation distance (creepage distance and clearance distance) between the anode terminal TA, to which a high voltage is applied, and other conductors (e.g., the cathode terminal TC and the gate terminal TG).

[0025] 4 illustrates an example in which the outer shell pattern layer M6 is provided so as to be continuous across the upper surface, outer side surface, and lower surface of the outer shell 51, that is, so as to be exposed to the outside of the outer shell 51. However, this is not limiting. For example, as shown in FIG. 5, the outer shell pattern layer M6 may be provided so as to be continuous across the upper surface, inner side surface, and lower surface of the outer shell 51. Alternatively, the outer shell pattern layer M6 may be provided inside the outer shell 51.

[0026] Next, specific shapes of the light emitting element 10 will be illustrated. FIG. 6(A) is a perspective view of the light emitting element 10 according to the first embodiment, and FIG. 6(B) is an exploded perspective view of the light emitting element 10 according to the first embodiment. In the first embodiment, the outer casing 51 is formed in a hollow rectangular parallelepiped shape that is open downward. A rectangular opening 51K is provided in the center of the top surface, and the opening 51K is blocked by a rectangular light-emitting unit 21. The substrate 31 is formed in a rectangular plate shape that is larger in both the front and rear and left and right directions than the outer casing 51. A single electron beam source 11 is mounted in the center of the substrate 31. In addition, a groove 31M into which the lower part of the outer casing 51 fits is formed around the periphery of the upper surface 31A of the substrate 31. This groove 31M makes it easier to position the outer casing 51. This groove 31M and the lower part of the outer casing 51 are blocked by pattern layers M7 and M6 and a metal bonding material MB3 shown in FIG. 4. Note that the outer casing pattern layer M6 is not shown in FIGS. 6(A) and 6(B).

[0027] FIG. 7 is a diagram showing the substrate 31 of the light emitting device 10 according to the first embodiment. As shown in Figure 7, the upper surface 31A of the substrate 31 is provided with a substrate upper surface cathode pattern layer M2 to which the lower electrode 11B of the electron beam source 11 is connected, a substrate upper surface gate pattern layer M4 to which the upper electrode 11A of the electron beam source 11 is connected, and a substrate upper surface anode pattern layer M7 connected to the outer portion pattern layer M6. The substrate upper surface anode pattern layer M7 is provided along a predetermined polygonal or curved shape, and the substrate upper surface cathode pattern layer M2 and the substrate upper surface gate pattern layer M4 are provided in an area corresponding to the center of this predetermined shape. This allows the substrate upper surface anode pattern layer M7, to which a high voltage is applied, to be effectively separated from other conductive patterns (pattern layers M2, M4, etc.), making it easier to ensure insulation distances (creepage distances and clearance distances) between the substrate upper surface anode pattern layer M7 and other conductive patterns.

[0028] More specifically, the substrate upper surface anode pattern layer M7 is provided so as to have a rectangular frame shape that follows the outer periphery of the substrate 31. The area in which this substrate upper surface anode pattern layer M7 is provided is within the groove 31M (see FIG. 6 ) into which the lower part of the outer frame 51 fits. In other words, it is the area of ​​the upper surface 31A of the substrate 31 that is the shape of the lower surface of the outer frame 51 projected onto the upper surface 31A of the substrate 31. Therefore, the substrate upper surface anode pattern layer M7 extends between the outer frame 51 and the substrate 31, making it easier to align the boundary structure between the outer frame 51 and the substrate 31. Note that it is also preferable that the outer frame pattern layer M6 also extends between the outer frame 51 and the substrate 31, as shown in FIGS. 2 and 5 . This is advantageous for simplifying the airtight structure between the outer frame 51 and the substrate 31 and maintaining airtightness. The substrate upper surface cathode pattern layer M2 and the substrate upper surface gate pattern layer M4 are provided adjacent to each other in a region corresponding to the center of the substrate 31 with a minimum gap therebetween.

[0029] As shown in Figure 7, the lower surface 31B of the substrate 31 is provided with a cathode terminal TC connected to the substrate upper surface cathode pattern layer M2, a gate terminal TG connected to the substrate upper surface gate pattern layer M4, and an anode terminal TA connected to the substrate upper surface anode pattern layer M7. The anode terminal TA is provided with a constant width in the region of one of the two opposing sides of the substrate 31. The cathode terminal TC and the anode terminal TA are provided in a region corresponding to the center of the lower surface 31B of the substrate 31, at positions that overlap the substrate upper surface cathode pattern layer M2 and the substrate upper surface cathode pattern layer M2, respectively, in the vertical direction.

[0030] As shown in FIG. 7, even on the lower surface 31B of the substrate 31, the anode terminal TA to which a high voltage is applied can be effectively separated from other conductive patterns (such as the cathode terminal TC and the gate terminal TG), making it easier to ensure an insulation distance (creepage distance and spatial distance) between the anode terminal TA and other conductive patterns.

[0031] 7, a pattern layer M8 (hereinafter referred to as a fixing pattern layer M8) is provided on at least a part of a region α of one side of the lower surface 31B of the substrate 31 that faces the other side on the anode terminal TA side of the substrate 31. If the fixing pattern layer M8 were not provided, when the substrate 31 was placed on a mounting substrate such as a printed circuit board, the substrate 31 might tilt relative to the mounting substrate by an amount equivalent to the thickness of the anode terminal TA. In contrast, when the fixing pattern layer M8 is provided, the anode terminal TA and the fixing pattern layer M8, which have approximately the same thickness, come into contact with the mounting substrate, so that the substrate 31 can be prevented from tilting relative to the mounting substrate.

[0032] As described above, in the light-emitting element 10 of this embodiment, the outer casing 51 is disposed on the upper surface 31A of the substrate 31 on which the electron beam source 11 is mounted, surrounding the electron beam source 11 from above, and the light-emitting section 21 having the light-emitting layer 21L is disposed above the outer casing 51. The space surrounded by the substrate 31, the outer casing 51, and the light-emitting section 21 is a vacuum. The light-emitting section 21 has an anode electrode 41 to which a high voltage for accelerating the electron beam is applied. A cathode terminal TC and a gate terminal TG electrically connected to the electron beam source 11, and an anode terminal TA electrically connected to the anode electrode 41 are disposed on the lower surface 31B of the substrate 31 in a planar manner so that the substrate 31 can be planarly mounted. This configuration can provide an electron-beam-excited light-emitting element (light-emitting element package) that can be easily manufactured using semiconductor microfabrication technology and can be easily mounted on a mounting substrate 100 such as a printed circuit board, as shown in FIG. 8(A).

[0033] According to the configuration of this embodiment, the configuration is not limited to mounting a single light emitting element 10 on the mounting substrate 100 as shown in Fig. 8(A), and it is also easy to mount a plurality of light emitting elements 10 on the mounting substrate 100 as shown in Fig. 8(B). In addition, it is also easy to mount a so-called multi-drive configuration in which a plurality of electron beam sources 11 are mounted on the substrate 31 as shown in Fig. 8(C), and it is also easy to mount a wide-area array of electron beam sources 11 on the substrate 31 as shown in Fig. 8(D).

[0034] It is also easy to change the positions of the electron beam source 11 and the conductive paths of the terminals TC, TG, TA, etc. relative to the substrate 31. This makes it easier to ensure the insulation distance (creepage distance and spatial distance) between the anode terminal TA to which a high voltage is applied and other conductive paths.

[0035] The outer casing 51 is an insulating member provided with an outer casing pattern layer M6 that is electrically connected to the anode electrode 41, and the substrate 31 is provided with a substrate pattern layer (corresponding to the substrate upper surface anode pattern layer M7) that is joined to the outer casing pattern layer M6 that constitutes the conductor of the outer casing 51 and is electrically connected to the anode terminal TA. With this configuration, the outer casing 51 is made of an insulator, and the outer casing pattern layer M6 can be used to electrically connect the anode electrode 41 and the anode terminal TA.

[0036] The outer casing 51 may be formed of a conductive material, and the outer casing 51 itself may be a conductor that electrically connects the anode electrode 41 and the anode terminal TA. Fig. 9 shows an example (second embodiment) of the light-emitting element 10 in which the outer casing 51 is a conductor, Fig. 9(A) shows the outer casing 51 of the light-emitting element 10 according to the second embodiment, and Fig. 9(B) is a diagram showing the cross-sectional structure of the light-emitting element 10 according to the second embodiment.

[0037] 9(A), the outer casing 51 is formed of a substantially cylindrical metal cap, and may be, for example, a component similar to the metal cap used in a TO-can semiconductor laser. As shown in FIG. 9(B), the light emitting unit 21 is placed on the upper surface of the outer casing 51, and the bonding electrode layer M5 exposed on the lower surface of the light emitting unit 21 is directly bonded to the outer casing 51 via a metal bonding material MB2. The lower surface of the outer casing 51 is directly bonded to the substrate upper surface anode pattern layer M7 exposed on the upper surface 31A of the substrate 31 via a metal bonding material MB1. In other words, the outer casing 51 is a conductor that can electrically connect the anode electrode 41 and the upper surface 31A of the substrate 31, and the substrate 31 is provided with a substrate pattern layer (corresponding to the substrate upper surface anode pattern layer M7) that is joined to the outer casing 51 and is electrically connected to the anode terminal TA. This allows the outer casing 51 to be configured as a metal cap and to serve as a conductor that electrically connects the anode electrode 41 provided in the light-emitting unit 21 and the anode terminal TA provided on the substrate 31.

[0038] The shape of the outer shell 51 and the structure of each part of the light emitting element 10 may be changed as appropriate. For example, Figure 9(B) illustrates a case in which the anode terminal TA and the conductor of the outer casing 51 are connected by a substrate pattern layer (corresponding to the substrate upper surface anode pattern layer M7) and a via structure ST3 such as a through-hole via that penetrates the substrate 31. However, as shown in Figure 9(C), a conductive member M7A such as a pattern layer that is continuous across the upper surface 31A, side and lower surfaces of the substrate 31 may be provided, and this conductive member M7A may be used to provide electrical continuity between the anode terminal TA and the conductor of the outer casing 51.

[0039] 7, the substrate pattern layer (corresponding to the substrate upper surface anode pattern layer M7) is provided on the upper surface 31A of the substrate 31 along a predetermined polygonal or curved shape, and the gate terminal TG and the cathode terminal TC are provided in a region corresponding to the center of the predetermined shape on the lower surface 31B of the substrate 31. Note that the predetermined shape may be set appropriately and does not have to be a closed polygonal shape or a closed curved shape (which can be said to be an endless shape) as exemplified in FIG. 7. This configuration makes it easier to ensure an insulating distance between the conduction path including the anode terminal TA to which a high voltage is applied and other conduction paths.

[0040] Furthermore, the substrate pattern layer (corresponding to the substrate upper surface anode pattern layer M7) has a shape that extends over the upper surface 31A of the substrate 31 within the range of the shape obtained by projecting the lower surface of the outer portion 51 onto the upper surface 31A of the substrate 31. With this configuration, the substrate pattern layer extends between the outer portion 51 and the substrate 31, making it easier to align the boundary structure between the outer portion 51 and the substrate 31. This is advantageous for simplifying the airtight structure between the outer portion 51 and the substrate 31 and maintaining airtightness.

[0041] The anode electrode 41 contains aluminum, and is provided with a bonding electrode layer M5 (see FIG. 4) containing at least one of Ti and Cr, and the bonding electrode layer M5 is bonded to the conductor of the outer casing 51 (the outer casing pattern layer M6 or the outer casing 51 itself of the conductor) via a metal bonding material MB2. This configuration makes it easy to bond the anode electrode 41 and the conductor of the outer casing 51 while using a vapor-deposited film containing aluminum, which has a strong surface oxidizing effect, for the anode electrode 41.

[0042] The light-emitting section 21 also includes a transparent substrate 21T that covers the opening 51K provided in the outer shell 51, a first thin film that is formed on the lower surface of the transparent substrate 21T and functions as the light-emitting layer 21L, and a second thin film that is formed on the lower surface of the light-emitting layer 21L and functions as the anode electrode 41. With this configuration, a small and thin light-emitting section 21 can be manufactured using semiconductor microfabrication technology. Furthermore, the light emitting layer 21L is configured to emit light having a peak wavelength in the deep ultraviolet wavelength range when exposed to electron beams, and is therefore suitable for disinfection, sterilization, sterilization, surface modification, and other uses.

[0043] The above embodiment is merely an example of one aspect of the present invention, and any modifications and applications are possible within the scope of the present invention. For example, although the light-emitting element 10 of the present invention has been described as being applied to a light-emitting element that emits deep ultraviolet light, it may also be applied to a light-emitting element that emits light other than deep ultraviolet light. Furthermore, the present invention may also be applied to an industrial light irradiation device that includes a mounting substrate 100 such as a printed circuit board on which the light-emitting element 10 is mounted and that irradiates an object with light from the light-emitting element 10. Examples of industrial light irradiation devices include a container sterilization device, an air sterilization device, a running water sterilization device, and a surface modification device.

[0044] The above embodiment supports the following configurations.

[0045] (Configuration 1) A light-emitting device comprising an electron beam source and a light-emitting section having a light-emitting layer excited by an electron beam from the electron beam source, wherein the electron beam source is mounted on a substrate, an outer casing that surrounds the electron beam source from above is disposed on an upper surface of the substrate, the light-emitting section is disposed above the outer casing, the space surrounded by the substrate, the outer casing, and the light-emitting section is a vacuum, the light-emitting section has an anode electrode to which a high voltage for accelerating the electron beam is applied, and a cathode terminal and a gate terminal that are electrically connected to the electron beam source and an anode terminal that is electrically connected to the anode electrode are disposed on a lower surface of the substrate in a planar manner so that the substrate can be planar-mounted. This configuration provides an electron beam excited light emitting element that can be easily fabricated using semiconductor microfabrication technology and easily mounted on a mounting substrate such as a printed circuit board. Furthermore, since the electron beam source is mounted on the substrate, it is easily adaptable to a multi-drive configuration in which multiple electron beam sources are mounted on the substrate, or to the mounting of electron beam sources in a wide-area array. Furthermore, the positions of the electron beam source and the conductive paths, such as the cathode terminal, gate terminal, and anode terminal, on the substrate can be easily changed, making it easier to ensure insulation distances (creepage distances and clearance distances) between the anode terminal to which a high voltage is applied and other conductive paths.

[0046] (Configuration 2) A light-emitting element according to configuration 1, wherein the outer casing is an insulating member provided with an outer casing pattern layer that is conductive to the anode electrode, and the substrate is provided with a substrate pattern layer that is joined to the outer casing pattern layer that constitutes the conductor of the outer casing and is conductive to the anode terminal. According to this configuration, the outer shell is made of an insulator, and the outer shell pattern layer can be used to establish electrical continuity between the anode electrode and the anode terminal.

[0047] (Configuration 3) A light-emitting element according to configuration 1, wherein the outer casing is a conductor capable of electrically connecting the anode electrode and the upper surface of the substrate, and the substrate is provided with a substrate pattern layer that is joined to the outer casing and electrically connected to the anode terminal. According to this configuration, the outer shell is a metal cap, which can be used as a conductor to electrically connect the anode electrode provided in the light-emitting portion and the anode terminal provided on the substrate.

[0048] (Structure 4) A light-emitting element described in structure 2 or 3, wherein the substrate pattern layer is provided on the upper surface of the substrate along a predetermined shape, and the gate terminal and cathode terminal are provided in an area corresponding to the center of the predetermined shape on the lower surface of the substrate. This configuration makes it easier to ensure an insulation distance between the conductive path including the anode terminal to which a high voltage is applied and other conductive paths.

[0049] (Configuration 5) The light-emitting device according to configuration 4, wherein the substrate pattern layer has a shape that extends on the upper surface of the substrate within a range of the shape obtained by projecting the lower surface of the outer portion onto the upper surface of the substrate. According to this configuration, the substrate pattern layer extends between the outer casing and the substrate, making it easier to align the boundary structure between the outer casing and the substrate, which is advantageous for simplifying the airtight structure between the outer casing and the substrate and maintaining airtightness.

[0050] (Configuration 6) A light-emitting element according to configuration 2 or 3, wherein the anode electrode contains aluminum, and the anode electrode is provided with a bonding electrode layer containing at least one of Ti and Cr, and the bonding electrode layer is bonded to the conductor of the outer casing via a metal bonding material. According to this configuration, the anode electrode is made of a vapor-deposited film containing aluminum, which has a strong surface oxidation effect, and the anode electrode and the conductor of the outer shell can be easily joined.

[0051] (Structure 7) The light-emitting element according to any one of structures 1 to 6, wherein the light-emitting portion comprises a transparent substrate covering an opening provided in the outer shell portion, a first thin film formed on the underside of the transparent substrate and functioning as the light-emitting layer, and a second thin film formed on the underside of the light-emitting layer and functioning as the anode electrode. According to this configuration, a small and thin light emitting section can be manufactured using semiconductor microfabrication technology.

[0052] (Configuration 8) The light-emitting device according to any one of configurations 1 to 7, wherein the light-emitting layer emits deep ultraviolet light when exposed to the electron beam. This configuration is suitable for applications such as disinfection, sterilization, sterilization, and surface modification.

[0053] (Configuration 9) A light irradiation device for industrial use, comprising a printed circuit board on which the light emitting element according to any one of configurations 1 to 8 is mounted, for irradiating an object with light from the light emitting element. According to this configuration, it is possible to provide a light irradiation device for industrial use that includes an electron beam excited light emitting element that can be easily mounted on a printed circuit board and irradiates an object with light from this light emitting element. [Explanation of symbols]

[0054] 10 Light emitting element (light emitting element package) 11 Electron beam source 11A upper electrode 11B Lower electrode 21 Light-emitting part 21L Emitting layer (first thin film) 21T transparent substrate 31 PCB 41 Anode electrode (second thin film) 51 Outer wall 51K opening 100 Mounting board (printed circuit board) M1 lower electrode layer M2: Pattern layer for cathode on top of substrate M3 upper electrode layer M4 PCB top pattern layer M5 Bonding electrode layer (conductive material) M6 Outer pattern layer M7 Substrate top anode pattern layer (substrate pattern layer) M8 Fixing Pattern Layer MB1~MB3 Metal bonding material TC cathode terminal TG Gate terminal TA Anode terminal

Claims

1. A light-emitting device comprising: an electron beam source; and a light-emitting section having a light-emitting layer excited by an electron beam from the electron beam source, the electron beam source is mounted on a substrate, an outer casing is disposed on an upper surface of the substrate so as to surround the electron beam source from above, and the light emitting unit is disposed above the outer casing; a space surrounded by the substrate, the outer shell, and the light-emitting portion is a vacuum; the light-emitting unit has an anode electrode to which a high voltage for accelerating the electron beam is applied, A cathode terminal and a gate terminal that are electrically connected to the electron beam source, and an anode terminal that is electrically connected to the anode electrode are arranged on the lower surface of the substrate in a planar manner so that the substrate can be surface-mounted. Light-emitting element.

2. The outer shell is an insulating member provided with an outer shell pattern layer that is electrically connected to the anode electrode, and the substrate is provided with a substrate pattern layer that is bonded to the outer shell pattern layer that constitutes the conductor of the outer shell and is electrically connected to the anode terminal. The light-emitting device according to claim 1 .

3. the outer shell is a conductor that can electrically connect the anode electrode and an upper surface of the substrate, The substrate is provided with a substrate pattern layer that is bonded to the outer shell and is electrically connected to the anode terminal. The light-emitting device according to claim 1 .

4. the substrate pattern layer is provided on the upper surface of the substrate along a predetermined shape; The gate terminal and the cathode terminal are provided in a region corresponding to the center of the predetermined shape on the lower surface of the substrate. The light-emitting device according to claim 2 or 3.

5. The substrate pattern layer has a shape that extends on the upper surface of the substrate within a range of a shape obtained by projecting the lower surface of the outer portion onto the upper surface of the substrate. The light-emitting device according to claim 4 .

6. the anode electrode includes aluminum; The anode electrode is provided with a bonding electrode layer containing at least one of Ti and Cr, and the bonding electrode layer is bonded to the conductor of the outer shell portion via a metal bonding material. The light-emitting device according to claim 2 or 3.

7. The light emitting unit includes a transparent substrate that covers the opening provided in the outer portion, a first thin film that is formed on a lower surface of the transparent substrate and functions as the light emitting layer, and a second thin film that is formed on a lower surface of the light emitting layer and functions as the anode electrode. The light-emitting device according to claim 1 .

8. The light-emitting layer emits deep ultraviolet light by the electron beam. The light-emitting device according to claim 1 .

9. A printed circuit board on which the light-emitting element according to any one of claims 1 to 3 is mounted, An industrial light irradiation device that irradiates an object with light from the light emitting element.

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