Light source module

Abstract

To provide a light source module in which extraction efficiency of ultraviolet light is improved, and stress generated on the light-emitting element is reduced as much as possible even if an arrangement ratio of light-emitting elements for a mounting substrate is high.SOLUTION: A light source module comprises: a plurality of semiconductor light-emitting elements 31, 140 which emit ultraviolet light for sterilizing fluid; mounting substrates 32, 135 on which the plurality of semiconductor light-emitting elements 31, 140 are directly mounted; translucent members 35, 132 which transmit ultraviolet light, and partition the plurality of semiconductor light-emitting element 31, 140 and the mounting substrates 32, 135 from fluid; and liquid substances 37, 137 which are filled in a space surrounded by an outer shape of the a plurality of semiconductor light-emitting elements 31, 140, the mounting substrate 32, 135 and the translucent member 35, 132.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a light source module.

Background Art

[0002] There is known a sterilization device that sterilizes bacteria and viruses in running water by irradiating ultraviolet light. A mercury lamp has been widely used as a light source for ultraviolet light. Since the mercury lamp uses mercury, it has a problem of strong toxicity and a large environmental load. In addition, when a mercury lamp is used, there is also a problem that the sterilization device becomes large. Therefore, the replacement of the mercury lamp with an ultraviolet LED is in progress.

[0003] Patent Document 1 discloses a water sterilization device using an LED that emits ultraviolet light, in which an ultraviolet light irradiation module is disposed near a water inlet provided at one end of a flow path tube through which water flows, and ultraviolet light is emitted from the ultraviolet light irradiation module in the axial direction of the flow path tube.

[0004] The ultraviolet light irradiation module has a plurality of light emitting elements, a substrate, a housing portion, and a transparent window. The plurality of light emitting elements are ultraviolet LEDs that emit ultraviolet light and are mounted on the substrate. The plurality of light emitting elements and the substrate are housed in the housing portion. An opening for extracting the ultraviolet light emitted from the light emitting elements is provided in the housing portion. The transparent window is installed so as to close the opening of the housing portion. Thereby, the light emitting elements are hermetically sealed in the ultraviolet light irradiation module.

[0005] Patent Document 2 discloses a configuration in which, in a chip-on-board LED module in which a plurality of light emitting elements (LEDs) are mounted on a substrate, the plurality of light emitting elements and the substrate are covered and protected with a transparent curable resin.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the configuration disclosed in Patent Document 1, when the ultraviolet light emitted from the light-emitting element diffuses in the space inside the housing portion, the amount of ultraviolet light that can be extracted from the opening portion decreases. Therefore, it is preferable to increase the extraction efficiency of the ultraviolet light by directing the ultraviolet light emitted from the light-emitting element toward the opening portion as much as possible.

[0008] In this regard, in the configuration disclosed in Patent Document 1, there is no detailed mention of the space inside the housing portion, that is, the space surrounded by the substrate, the plurality of light-emitting elements, and the transparent window, and it is understood that there is merely air in the space.

[0009] In the configuration disclosed in Patent Document 2, when the resin cures in the manufacturing process of the chip-on-board LED module, stress due to the curing of the resin is generated on the light-emitting element, leading to a decrease in the durability of the light-emitting element. In particular, when the arrangement ratio of the light-emitting elements with respect to the mounting substrate is increased, the distance between adjacent light-emitting elements is narrowed. However, when the distance between adjacent light-emitting elements is narrowed, the resin cures in a narrow space, so that the stress on the light-emitting element further increases.

[0010] The present invention has been made in view of such a background, and aims to provide a light source module in which the extraction efficiency of ultraviolet light is improved and the stress generated on the light-emitting element is reduced as much as possible even when the arrangement ratio of the light-emitting elements with respect to the mounting substrate is high.

Means for Solving the Problems

[0011] One aspect of the present invention is a plurality of semiconductor light-emitting elements that emit ultraviolet light for sterilizing a fluid, a mounting substrate on which the plurality of semiconductor light-emitting elements are directly mounted, A light-transmitting member that transmits ultraviolet light and separates a plurality of semiconductor light-emitting elements, a mounting substrate, and a fluid, A light source module includes a liquid substance filled in a space surrounded by the outer shapes of a plurality of semiconductor light-emitting elements, a mounting substrate, and the light-transmitting member.

Advantages of the Invention

[0012] In the light source module of the above aspect, the extraction efficiency of ultraviolet light is improved by the liquid substance filled in the space surrounded by the outer shapes of the plurality of semiconductor light-emitting elements, the mounting substrate, and the light-transmitting member. Since the substance filled in the space surrounded by the outer shapes of the plurality of semiconductor light-emitting elements, the mounting substrate, and the light-transmitting member is a liquid substance, the stress generated in the semiconductor light-emitting elements is reduced even when the arrangement ratio of the light-emitting elements with respect to the mounting substrate is high as compared with the case where the substance is a cured resin.

Brief Description of the Drawings

[0013]

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Embodiments for Carrying Out the Invention

[0014] The light source module includes a plurality of semiconductor light-emitting elements that emit ultraviolet light for sterilizing a fluid, a mounting substrate on which the plurality of semiconductor light-emitting elements are directly mounted, a light-transmitting member that transmits ultraviolet light and separates the plurality of semiconductor light-emitting elements, the mounting substrate, and the fluid, and a liquid substance filled in a space surrounded by the outer shapes of the plurality of semiconductor light-emitting elements, the mounting substrate, and the light-transmitting member.

[0015] In the above light source module, among the plurality of semiconductor light-emitting elements, adjacent semiconductor light-emitting elements are directly mounted on the mounting substrate in a state where their side surfaces are in contact with each other. According to this, the stress generated on the side surfaces of adjacent semiconductor light-emitting elements can be reduced.

[0016] In the above light source module, gas exists in the gap between the side surfaces of the adjacent semiconductor light-emitting elements. According to this, the emission from the element side surface can be suppressed, and the directivity can be improved.

[0017] In the above light source module, the surface roughness Ra of the side surface is 0.1 nm or more and 100000 nm. According to this, the emission from the element side surface can be suppressed, and the directivity can be improved.

[0018] In the above light source module, the maximum gap between the side surfaces of the adjacent semiconductor light-emitting elements is 200000 nm or less. Thereby, the emission from the element side surface can be suppressed, and the directivity can be improved.

[0019] In the above light source module, the contact angle of the liquid substance is 10° or more. According to this, gas is likely to exist in the gap between the side surfaces of adjacent semiconductor light-emitting elements.

[0020] In the above-described light source module, among the plurality of semiconductor light-emitting elements, adjacent semiconductor light-emitting elements are directly mounted on the mounting substrate in a state where their side surfaces are separated from each other by a distance of 5.0 mm or less. Thereby, emission from the side surfaces of the elements can be suppressed, and the directivity can be improved.

[0021] In the above-described light source module, the liquid substance is filled between the side surfaces of the adjacent semiconductor light-emitting elements. Thereby, the extraction efficiency of ultraviolet light from the side surfaces of the adjacent semiconductor light-emitting elements can be improved.

[0022] In the above-described light source module, gas exists between the side surfaces of the adjacent semiconductor light-emitting elements. According to this, emission from the side surfaces of the elements can be suppressed, and the directivity can be improved.

[0023] In the above-described light source module, the contact angle of the liquid substance is 50° or less. Thereby, the liquid substance is easily filled between the side surfaces of the adjacent semiconductor light-emitting elements.

[0024] In the above-described light source module, the liquid substance is a fluorine-based inert liquid. Thereby, the extraction efficiency of ultraviolet light emitted by the plurality of semiconductor light-emitting elements can be effectively improved.

[0025] (Embodiment 1) 1. Outline of the Configuration of the Fluid Sterilizer 1 FIG. 1 is a cross-sectional view showing the configuration of the fluid sterilizer 1 in the present embodiment, and is a cross-section in a plane including the axis of the fluid sterilizer 1. FIG. 2 is an exploded view of the fluid sterilizer 1 in the present embodiment. FIG. 3 is a cross-sectional view showing the configuration of the light source module 30 in the present embodiment. As shown in FIGS. 1 and 2, the fluid sterilizer 1 of the present embodiment includes a housing 10, a flow path tube 20, a light source module 30, a spacer 40, and a plate 50. Further, as shown in FIGS. 2 and 3, the light source module 30 includes a semiconductor light-emitting element 31 (LED chip), a mounting substrate 32, a seal member 33, a light source case 34, and a light-transmitting member 35.

[0026] The fluid sterilization device 1 of this embodiment is a device that flows fluid inside a flow path pipe 20 and a spacer 40, and irradiates the fluid with ultraviolet light emitted from a light source module 30 to sterilize it. The internal spaces of the flow path pipe 20 and the spacer 40 are a flow path space 70 (a space through which the fluid flows during sterilization and is an area irradiated with ultraviolet light). The fluid to be sterilized can be any liquid such as water, oil, alcohol, etc. As long as it has fluidity, it may be in a state where a solid is mixed with the liquid. In this specification, a mixture of a liquid and a solid that has fluidity is also included in the fluid. In this embodiment, water is used as the fluid to be sterilized. Note that although the fluid sterilization device 1 of this embodiment is substantially cylindrical, it may have any shape as long as it can allow the fluid to flow, for example, it may be cylindrical such as a rectangular tube shape.

[0027] 2. Details of each component of the fluid sterilization device 1 Next, each component of the fluid sterilization device 1 will be described in detail.

[0028] 2-1. Housing 10 As shown in FIGS. 1 and 2, the housing 10 is cylindrical, and an inlet 11 is provided at one end face in the axial direction, and an outlet 12 is provided at the side surface of the cylinder that is near the other end face and constitutes the housing 10. The material of the housing 10 is, for example, black PP (polypropylene). Inside the housing 10, a plate 50, a flow path pipe 20, and a spacer 40 are coaxially arranged in order from the inlet 11 side.

[0029] The other end face of the housing 10 is open. A thread 13 is provided on the inner peripheral surface of the cylinder near the other end face. The end face of the housing 10 on the thread 13 side is sealed by a light source module 30. The light source module 30 is fitted into the housing 10 and screwed by the thread 13.

[0030] An O-ring 60 is provided between the housing 10 and the plate 50, between the plate 50 and the flow path pipe 20, and between the flow path pipe 20 and the spacer 40 to prevent water from leaking between the members. The water flowing in from the inlet 11 is irradiated with ultraviolet light emitted from the light source module 30 in the process of sequentially passing through the plate 50, the flow path pipe 20, and the spacer 40, and is discharged from the outlet 12. Note that the positions of the inlet 11 and the outlet 12 may be arbitrary, and their positions may be interchanged.

[0031] 2-2. Flow Path Pipe 20 The flow path pipe 20 is composed of a cylindrical member, and the internal space of the cylindrical member serves as the flow path space. In the present embodiment, as shown in FIG. 1, the flow path pipe 20 is cylindrical and has a transparent pipe 21 and a reflector 22 provided in contact with the outer peripheral surface of the transparent pipe 21. The outer peripheral surface of the reflector 22 is in contact with the inner peripheral surface of the housing 10. The reflector 22 has a high reflectivity of ultraviolet light and can efficiently irradiate the water flowing through the flow path pipe 20 with ultraviolet light by reflecting the ultraviolet light on the side surface of the flow path pipe 20. Note that the extending direction of the central axis 20a of the flow path pipe 20 is defined as the axial direction Y.

[0032] The transparent pipe 21 is a cylindrical pipe made of quartz and allows water to be sterilized to flow inside. The material of the transparent pipe 21 is not limited to quartz and may be any material that transmits ultraviolet light and has a low absorption rate. For example, sapphire, ultraviolet light-transmitting glass, fluororesin, etc. may be used. In particular, a material with a small refractive index difference from water is preferable, and quartz in the present embodiment is suitable in this regard. For example, a material with a refractive index of 1.3 to 1.5 is preferable.

[0033] The thickness of the transparent pipe 21 is arbitrary as long as it has a strength to withstand water pressure and ultraviolet light transmittance, for example, 0.4 to 3 mm. A material and thickness with an ultraviolet light transmittance of 80% or more in the case of normal incidence are preferable.

[0034] The inner peripheral surface of the transparent tube 21 is preferably as flat as possible. For example, the RMS (root mean square height) is preferably 1 μm or less. Bacteria are less likely to adhere to the unevenness of the inner peripheral surface, dirt is less likely to adhere to the inner peripheral surface, a decrease in the sterilization efficiency can be suppressed, and the generation of bubbles and the like can also be prevented. By forming a water-repellent film such as a fluororesin on the inner peripheral surface of the transparent tube 21, the inner peripheral surface of the transparent tube 21 can be made to repel water, and dirt can be prevented from adhering to the inner peripheral surface of the transparent tube 21.

[0035] The reflector 22 is provided in contact with the outer peripheral surface of the transparent tube 21. The reflector 22 reflects the ultraviolet light that passes through the transparent tube 21 and goes to the outside.

[0036] The reflector 22 is formed by winding an unfired PTFE (polytetrafluoroethylene) film around the outer peripheral surface of the transparent tube 21 one to a plurality of times. That is, the reflector 22 is a laminate in which an unfired PTFE film is laminated on the transparent tube 21. The unfired PTFE film is a film such as a sheet or tape obtained by rolling PTFE fine powder without firing. Further, the PTFE fine powder is a white powder in which fine particles of PTFE are aggregated.

[0037] For the PTFE fine powder, for example, the powder for paste extrusion molding (II-1 or II-2) standardized in JIS K 6896:1995 can be used. II-1 satisfies the following characteristics. The apparent density (g / ml) is 0.50 ± 0.15, the moisture content (%) is 0.04 or less, the high-temperature volatile content (%) is 0.1 or less, the melting point (°C) is 327 ± 10, the specific gravity is 2.13 to 2.20, the tensile strength (MPa) is 17.6 or more, and the elongation (%) is 200 or more. The measurement methods of these characteristics are based on JIS K 6896:1995. Further, II-2 has the same characteristics as II-1 except that the specific gravity is 2.18 to 2.28.

[0038] As the PTFE green film, a green film manufactured using the powder for paste extrusion standardized in JIS K 6896:1995 and containing no additives can be used. In particular, the PTFE green tape standardized in JIS K 6885:2005 can be used. The PTFE green tape standardized in JIS K 6885:2005 meets the following quality requirements. The apparent density (g / cm 3 ) is 1.0 or more, the tensile strength (MPa) is 7.0 or more, the elongation (%) is 20 or more, the volatile content reduction (%) is 0.5 or less, and it is non-combustible. The measuring methods for these qualities are based on JIS K 6885:2005.

[0039] Since the PTFE green film is green (unfired), it has self-fusing properties. Therefore, when the PTFE green film is wound around the transparent tube 21, the gap between the transparent tube 21 and the PTFE green film and the gap between the PTFE green films disappear. Thus, the PTFE green film can be closely adhered and fixed to the transparent tube 21 without using an adhesive or the like, and the reflector 22 can be easily formed.

[0040] A small air layer may remain in the gap between the transparent tube 21 and the PTFE green film or between the PTFE green films. Even if an air layer remains, there is reflection due to the refractive index difference at the interface with the air layer, and the ultraviolet light transmitted through the air layer is reflected by the PTFE green film. Therefore, it does not have much effect on the ultraviolet light reflectance of the reflector 22. Therefore, when winding the PTFE green film around the transparent tube 21 to form the reflector 22, it is not necessary to wind it tightly so that no air layer remains, and the reflector 22 can be easily formed.

[0041] The reflector 22 has a high reflectivity to ultraviolet light. This is due to the following reasons. First, because PTFE itself is a material with a high ultraviolet light reflectivity. Second, because there are no gaps between the transparent tube 21 and the unfired PTFE film, and between unfired PTFE films, due to the self-fusing property of the unfired PTFE film. Third, because PTFE fine powder becomes fibrous when a shear stress is applied, the particles of the unfired PTFE film are fibrous, and as a result, the density of the particles is high.

[0042] The thickness of the reflector 22 is preferably 0.02 mm or more, and the number of windings of the unfired PTFE film may be set so as to achieve such a thickness. A reflectivity equal to or higher than that of barium sulfate, which is a common material as a reflector, can be achieved. In particular, the thickness of the reflector 22 is preferably 0.2 mm or more. An ultraviolet light reflectivity equal to or higher than that in the case where the flow path tube 20 is made of an 8-mm-thick PTFE bulk can be realized. There is no particular upper limit to the thickness of the reflector 22, but as it gets thicker, the ultraviolet light reflectivity saturates, so it is preferably 2 mm or less. Also, the thickness of the reflector 22 may be thinner than the thickness of the transparent tube 21. Also, the thickness and width of the unfired PTFE film may be arbitrary, or may be values standardized in JIS K 6885:2005.

[0043] In this embodiment, the flow path tube 20 has the transparent tube 21 and the reflector 22, but the entire flow path tube 20 may be formed in a cylindrical shape of PTFE, SUS, titanium, or polyvinyl chloride. A flow path tube 20 may be a member formed by coating a fluororesin on the inner peripheral surface or the outer peripheral surface of a cylindrical member formed of these materials.

[0044] O-rings 60 are respectively arranged at both ends of the flow path tube 20. Therefore, it is possible to prevent water from entering between the outer peripheral surface of the transparent tube 21 and the inner peripheral surface of the housing 10, more specifically, between the outer peripheral surface of the transparent tube 21 and the inner peripheral surface of the reflector 22, and between the outer peripheral surface of the reflector 22 and the inner peripheral surface of the housing 10.

[0045] As the reflector 22, in addition to the above, aluminum or the like may be used. For example, the reflector 22 can also be formed by winding a thin film of aluminum around the outer peripheral surface of the transparent member 21, or by forming a thin film of aluminum on the outer peripheral surface of the transparent tube 21 by vapor deposition or sputtering. In this case, it is desirable that the film thickness of the aluminum is 25 μm or more.

[0046] 2-3. Light source module 30 As shown in FIGS. 1, 2, and 3, the light source module 30 is cylindrical, and a thread 36 is provided on the side surface of the cylinder (the side surface of the light source case 34). As shown in FIG. 1, the thread 36 of the light source module 30 corresponds to the thread 13 of the housing 10. The light source module 30 is screwed into the open end surface of the housing 10, so that the thread 36 of the light source module 30 and the thread 13 of the housing 10 are engaged and screwed together. The light source module 30 is disposed at one axial end of the flow path tube 20 via a spacer 40.

[0047] The light source module 30 emits ultraviolet light, and the ultraviolet light enters the spacer 40 and the inside of the flow path tube 20 from one end of the spacer 40. Thereby, the fluid flowing through the spacer 40 and the flow path tube 20 can be irradiated with ultraviolet light to sterilize the fluid.

[0048] 2-4. Spacer 40 As shown in FIGS. 1 and 2, the spacer 40 is disposed between the flow path tube 20 and the light source module 30. The spacer 40 is a cylindrical tube made of PTFE and is disposed coaxially with the flow path tube 20. The spacer 40 is provided to increase the irradiation efficiency of ultraviolet light on the fluid flowing through the flow path tube 20 by efficiently reflecting the ultraviolet light having a large angle with respect to the axial direction Y of the flow path tube 20 among the ultraviolet light emitted from the light source module 30.

[0049] 2-5. Plate 50 As shown in FIGS. 1 and 2, the plate 50 is disposed between the inlet 11 of the housing 10 and the flow path pipe 20. The plate 50 is disc-shaped and is arranged coaxially with the flow path pipe 20. The material of the plate 50 is PTFE. By using PTFE with high ultraviolet light reflectivity, the ultraviolet light reaching the end face on the inlet 11 side of the flow path pipe 20 is reflected back into the flow path pipe 20, enhancing the irradiation efficiency of the ultraviolet light on the fluid flowing through the flow path pipe 20. A plurality of through holes are provided in the plate 50. The fluid flowing in from the inlet 11 is dispersed by passing through the plurality of through holes of the plate 50 and then flows into the flow path pipe 20.

[0050] 3. Details of each component of the light source module 30 As shown in FIG. 3, the light source module 30 is substantially cylindrical and includes a semiconductor light emitting element 31, a mounting substrate 32, a sealing member 33, a light source case 34, and a light transmissive member 35. Further, as shown in FIG. 4, the light source module 30 has a liquid substance 37.

[0051] 3-1. Semiconductor light emitting element 31 As shown in FIG. 3, the semiconductor light emitting element 31 is mounted on the bottom surface 322 of the recess 321 of the mounting substrate 32. The semiconductor light emitting element 31 is a bare chip that emits ultraviolet light. The wavelength of the ultraviolet light can be determined according to the fluid flowing through the flow path space 70. In this embodiment, since water is adopted as the fluid, the wavelength of the ultraviolet light is preferably 250 to 285 nm, which is a wavelength with high sterilization efficiency for water. The configuration of the semiconductor light emitting element 31 is not limited, and any of a face-up type, a flip-chip type, and a vertically conductive type may be used. However, in this embodiment, the semiconductor light emitting element 31 adopts a flip-chip type. A plurality of semiconductor light emitting elements 31 are provided, and the number of the semiconductor light emitting elements 31 is not limited as long as it is two or more. In this embodiment, as shown in FIG. 3, three semiconductor light emitting elements 31 are included.

[0052] The semiconductor light-emitting element 31 has a rectangular parallelepiped shape. The surface opposite to the mounting substrate 32 constitutes the element main surface 31a, and all the side surfaces adjacent to the element main surface 31a constitute the element side surfaces 31b. The angle formed by the element main surface 31a and the element side surfaces 31b is in the range of 80 to 100°, preferably 90°, across the entire outer periphery of the element main surface 31a.

[0053] On the surface of the semiconductor light-emitting element 31 on the side of the mounting substrate 32, electrode pads (not shown) are provided. As schematically shown in FIG. 4, an active layer 31c is formed inside the semiconductor light-emitting element 31 between the n-type layer and the p-type layer.

[0054] Inside the semiconductor light-emitting element 31, an element substrate, an n-type layer, the active layer 31c, and a p-type layer are laminated in this order, and ultraviolet light is emitted from the active layer 31c. In the present embodiment, since the semiconductor light-emitting element 31 is of the flip-chip type, the element substrate of the semiconductor light-emitting element 31 is located on the surface opposite to the mounting substrate 32, and the n-type layer, the active layer 31c, and the p-type layer are formed on the side of the mounting substrate 32 with respect to the element substrate.

[0055] The thickness of the semiconductor light-emitting element 31 is 100 μm or more, preferably 400 μm or more. In particular, the thickness of the element substrate of the semiconductor light-emitting element 31 is 100 μm or more.

[0056] A plurality of semiconductor light-emitting elements 31 are directly mounted on the mounting substrate 32 in a state where the element side surfaces 31b of adjacent semiconductor light-emitting elements 31 are in contact with each other.

[0057] 3-2. Mounting Substrate 32 The mounting substrate 32 is a substrate on which the semiconductor light-emitting element 31 is mounted. As shown in FIG. 3, the mounting substrate 32 has a bottomed cylindrical shape and has a recess 321 on the side facing the flow path tube 20. The bottom surface 322 of the recess 321 has a planar shape perpendicular to the axial direction Y.

[0058] As shown in FIG. 3, a plurality of semiconductor light-emitting elements 31 are arranged on the bottom surface 322 of the recess 321.

[0059] As shown in FIG. 3, the side wall portion 323 of the recess 321 has an annular shape standing upright in the axial direction Y. As a result, the mounting substrate 32 has a bottomed cylindrical shape, and a cylindrical space is formed inside the recess 321. The upper surface of the side wall portion 323 is flat, and the light-transmitting member 35 is attached thereto.

[0060] A circuit forming member (not shown) electrically connected to the semiconductor light-emitting element 31 is mounted on the mounting substrate 32. The circuit forming member is a drive circuit for causing the semiconductor light-emitting element 31 to emit light, a connector header for connecting the drive circuit and a power cable, and the like. As other electronic components not shown, a thermistor for measuring the temperature of the mounting substrate, a connector header for connecting the thermistor and a power cable, and the like are provided on the mounting substrate.

[0061] The material of the mounting substrate is not limited, but aluminum is adopted in this embodiment. As the mounting substrate, a glass epoxy substrate such as FR-4 or CEM3, or a flexible substrate made of polyimide or the like may be used. In addition, various processes such as drilling may be performed on the mounting substrate.

[0062] 3-3. Light-transmitting member 35 The light-transmitting member 35 has light-transmitting properties that transmit ultraviolet light, and as shown in FIG. 3, covers the ultraviolet light emission side of the plurality of semiconductor light-emitting elements 31. In this embodiment, the light-transmitting member 35 is flat and is joined to the upper surface of the side wall portion 323 of the mounting substrate 32 by resin or solder. As a result, the inner space of the recess 321 is sealed. And the light-transmitting member 35 is configured to contact the flow path space 70.

[0063] The light-transmitting member 35 functions as a window that transmits the ultraviolet light emitted from the semiconductor light-emitting element 31. The ultraviolet light emitted from the plurality of semiconductor light-emitting elements 31 passes through the light-transmitting member 35 and enters the flow path space 70. Thereby, the fluid flowing through the flow path space 70 is sterilized by the ultraviolet light emitted from the plurality of semiconductor light-emitting elements 31. The light-transmitting member 35 and the semiconductor light-emitting element 31 are separated by a predetermined distance. In the present embodiment, the inner space of the concave portion 321 between the two is filled with the liquid substance 37.

[0064] Note that it is not necessary for the entire upper surface of the light-transmitting member 35 to be in contact with the flow path space 70, but it is preferable that the entire surface is in contact. Also, the side surface of the light-transmitting member 35 may be in contact with the flow path space 70.

[0065] The light-transmitting member 35 is not limited to a flat plate shape and may be a convex lens type. If it is a convex lens type, the directivity of the ultraviolet light emitted from the semiconductor light-emitting element 31 becomes high and the directivity angle becomes narrow, so that the ultraviolet light can be irradiated more efficiently to the fluid flowing through the flow path space 70. In particular, when the difference between the refractive index of the material of the light-transmitting member 35 and the refractive index of the fluid flowing through the flow path space 70 is large, it is preferable to use a convex lens type.

[0066] The material of the light-transmitting member 35 can be any material that transmits the ultraviolet light emitted from the semiconductor light-emitting element 31, but a material having a thermal conductivity of 0.25 W / m·K or more is preferable. This is for enhancing the heat dissipation efficiency. For example, sapphire, quartz, borosilicate glass, fluororesin, etc. can be used. In terms of enhancing the heat dissipation efficiency, a material having a high thermal conductivity is preferable, and sapphire is used in the present embodiment. Also, the light-transmitting member 35 may be formed of a material having a higher thermal conductivity than the thermal conductivity of the mounting substrate 32. Heat conduction from the semiconductor light-emitting element 31 to the light-transmitting member 35 through the inner space of the concave portion 321 can be performed more efficiently, and the heat dissipation efficiency can be improved.

[0067] The thickness of the light-transmitting member 35 is preferably 0.1 mm or more. Since the spread of heat becomes large and the heat dissipation area becomes wide, heat can be more efficiently dissipated to the fluid flowing through the flow path space 70 via the light-transmitting member 35. However, if the light-transmitting member 35 becomes too thick, the thermal resistance increases, so it is preferable to set the area and thickness of the light-transmitting member 35 so as to have appropriate heat dissipation characteristics.

[0068] 3-4. Light source case 34 As shown in FIGS. 2 and 3, the light source case 34 is cylindrical and holds the mounting substrate 32 inside. The material of the light source case 34 is not limited. In this embodiment, it is made of PP, but it may be made of SUS or the like instead. An opening 34b for transmitting ultraviolet light from the semiconductor light-emitting element 31 is provided on the upper surface (the surface on the spacer 40 side) of the light source case 34. Inside the light source case 34, the mounting substrate 32 is arranged such that the opening 34b and the light-transmitting member 35 overlap in the axial direction Y. In this embodiment, the upper surface of the light-transmitting member 35 is arranged flush with the bottom surface of the opening 34b.

[0069] A plurality of convex portions 34a are provided on the outer upper surface of the light source case 34. The convex portions 34a are in contact with the spacer 40. The convex portions 34a create a gap 34c between the upper surface of the light source case 34 and the spacer 40, allowing the fluid that has flowed through the flow path space 70 and reached the inside of the spacer 40 to flow to the discharge port 12 through the gap 34c. The inside of the spacer 40 and the gap 34c are also part of the flow path space 70.

[0070] A thread 36 is provided on the outer peripheral surface of the light source case 34. The thread 36 corresponds to the thread 13 provided on the inner peripheral surface of the housing 10. The light source module 30 fitted into the housing 10 is screwed in by engaging the thread 36 of the light source module 30 with the thread 13 of the housing 10. Note that the light source module 30 may be fixed to the housing 10 by a method other than screwing.

[0071] 3-5. Seal member 33 The sealing member 33 is a caulking material formed to fill the gap between the mounting substrate 32 and the light source case 34. The sealing member 33 is a polymer material having waterproof properties such as urethane resin, silicone resin, epoxy resin, etc. The side surface of the light source case 34 and circuit forming members such as the drive circuit of the mounting substrate 32 are covered by the sealing member 33, so that the electronic components mounted on the mounting substrate 32 are prevented from coming into contact with water. Note that the upper surface of the light-transmitting member 35 is not covered by the sealing member 33 and is in contact with the flow path space 70.

[0072] Note that heat conductive particles or heat conductive fibers may be mixed into the sealing member 33. By imparting high thermal conductivity to the sealing member 33, heat from the semiconductor light emitting element 31 can be easily dispersed through the sealing member 33, and the heat dissipation performance can be enhanced. In particular, it is preferable that the light source case 34 is also made of a material having high thermal conductivity such as metal, and both the sealing member 33 and the light source case 34 are made of materials having high thermal conductivity.

[0073] Since the light source case 34 is in contact with the flow path space 70, the light source case 34 is in direct contact with the fluid flowing through the flow path space 70, and heat can be dissipated from the sealing member 33 through the light source case 34 to the fluid flowing through the flow path space 70. Therefore, the heat dissipation performance can be further enhanced. The sealing member 33 may be brought into contact with the flow path space 70, and heat may be dissipated from the sealing member 33 to the fluid flowing through the flow path space 70.

[0074] 3-6. Liquid Substance 37 The liquid substance 37 is filled in the inner space of the recess 321 of the mounting substrate 32 (the space sealed by the light-transmitting member 35). As shown in FIG. 4, the liquid substance 37 has a main facing portion 37a and a sub-facing portion 37b. The main facing portion 37a is the portion filled in the region where the light-transmitting member 35 and the element main surface 31a face each other in the liquid substance 37. Therefore, the liquid substance 37 is in contact with the light-transmitting member 35 and the element main surface 31a of the semiconductor light emitting element 31.

[0075] The sub-opposing portion 37b is the portion filled in the region where the side wall portion 323 of the recess 321 and the element side surface 31b of the semiconductor light-emitting element 31 face each other among the liquid substances 37. Therefore, the liquid substance 37 is in contact with the side wall portion 323 of the recess 321 and the element side surface 31b of the semiconductor light-emitting element 31.

[0076] The sub-opposing portion 37b is filled up to the region facing the side surface of the active layer 31c of the semiconductor light-emitting element 31. That is, the side surface of the active layer 31c of the semiconductor light-emitting element 31 faces the liquid substance 37.

[0077] The liquid substance 37 is liquid at normal temperature and normal pressure. The liquid substance 37 is an inert compound and can be at least one selected from the group such as fluorine-based inert liquids, silicon compounds, phosphate compounds, etc.

[0078] As an example of the liquid substance 37, a fluorine-based inert liquid is preferably a fluorocarbon compound which is a polymer having a CF bond. The number of carbon atoms in the fluorocarbon compound is 1.9 times or less the number of fluorine atoms in the fluorocarbon compound. The fluorocarbon compound is, for example, perfluoropolyether (PFPE), hydrofluoroether (HFE), etc.

[0079] 4. Details of the liquid substance 37 The liquid substance 37 contains at least one selected from the group such as fluorine compounds, silicon compounds, phosphate compounds, etc. The viscosity of the liquid substance 37 is 0.01 - 50 Pa·s, preferably 0.1 - 50 Pa·s, and more preferably 1 - 50 Pa·s.

[0080] The contact angle of the liquid substance 37 at a temperature of 25°C is 15° - 25°, preferably 27° - 23°, and more preferably 20°. Due to these, the main opposing portion 37a of the liquid substance 37 is held by capillary action. Thereby, the sub-opposing portion 37b of the liquid substance 37 is held by capillary action.

[0081] In particular, the arithmetic mean roughness Ra of the element main surface 31a and the element side surface 31b of the semiconductor light-emitting element 31 is 0.1 to 100000 nm. Also from this, due to capillary action, the main facing portion 37a and the sub-facing portion 37b of the liquid substance 37 are held. Furthermore, the semiconductor light-emitting element 31 is formed in a shape without notches or dents such as cuts over the entire outer periphery of the element main surface 31a at the boundary between the element main surface 31a and the element side surface 31b. Therefore, the main facing portion 37a and the sub-facing portion 37b of the liquid substance 37 are held. Thereby, emission from the element side surface can be suppressed and the directivity can be improved.

[0082] The maximum gap between the element side surfaces 31b of adjacent semiconductor light-emitting elements 31 is 200000 nm or less. Thereby, emission from the element side surface can be suppressed and the directivity can be improved.

[0083] From this, gas exists in the gap between the element side surfaces 31b of adjacent semiconductor light-emitting elements 31. Thereby, emission from the element side surface can be suppressed and the directivity can be improved.

[0084] The boiling point of the liquid substance 37 is 150°C or higher, preferably 200°C or higher. The junction temperature Tj of the semiconductor light-emitting element 31 during operation is set to be 150°C or lower, preferably 100°C or lower. In particular, the boiling point of the liquid substance 37 is 50°C or higher, preferably 100°C or higher, higher than the junction temperature Tj of the semiconductor light-emitting element 31 during operation. Therefore, even if the temperature of the semiconductor light-emitting element 31 rises, vaporization of the liquid substance 37 can be prevented and the state in which the main facing portion 37a and the sub-facing portion 37b are held by capillary action can be maintained.

[0085] The liquid substance 37 has a transmittance of ultraviolet light with an emission wavelength of 280 nm of 50% or more, preferably 80% or more. Further, the refractive index of the liquid substance 37 is closer to the refractive index of the light-transmitting member 35 than the refractive index of air. In this embodiment, the refractive index of the liquid substance 37 is preferably greater than the refractive index of air and equal to or less than the refractive index of the light-transmitting member 35. When the liquid substance 37 is a fluorocarbon compound, the refractive index of the fluorocarbon compound is, for example, 1.2 or more and 1.6 or less.

[0086] 6. Path of ultraviolet light The path of the ultraviolet light emitted from the semiconductor light-emitting element 31 will be described. The ultraviolet light emitted from the active layer 31c of the semiconductor light-emitting element 31 is output from the element main surface 31a of the semiconductor light-emitting element 31. The main facing portion 37a of the liquid substance 37 is filled in the region where the element main surface 31a of the semiconductor light-emitting element 31 and the light-transmitting member 35 face each other. Therefore, in the direction perpendicular to the element main surface 31a, the light-transmitting member 35 is disposed via the liquid substance 37. The emitted ultraviolet light is incident on the light-transmitting member 35 from the element main surface 31a through the liquid substance 37 and is output to the outside from the light-transmitting member 35.

[0087] Here, the liquid substance 37 is in contact with the element main surface 31a, and the liquid substance 37 is in contact with the light-transmitting member 35. Therefore, the emitted ultraviolet light is suppressed from being reflected at the element main surface 31a and is output from the light-transmitting member 35.

[0088] The ultraviolet light emitted from the active layer 31c of the semiconductor light-emitting element 31 is also output from the element side surface 31b of the semiconductor light-emitting element 31. The sub-facing portion 37b of the liquid substance 37 is filled in the region where the element side surface 31b of the semiconductor light-emitting element 31 and the side wall portion 323 of the concave portion 321 face each other. The emitted ultraviolet light is output from the element side surface 31b through the sub-facing portion 37b of the liquid substance 37 to the light-transmitting member 35.

[0089] Here, the liquid substance 37 is in contact with the element side surface 31b, and the liquid substance 37 is in contact with the light-transmitting member 35. Therefore, the emitted ultraviolet light is suppressed from being reflected at the element side surface 31b and is output from the light-transmitting member 35.

[0090] 7. Manufacturing method of the light source module 30 A manufacturing method of the light source module 30 will be described. In the first step, each semiconductor light emitting element 31 is bonded to the bottom surface 322 of the recess 321 of the mounting substrate 32.

[0091] Subsequently, in the second step, the liquid substance 37 is dropped onto the main element surface 31a of each semiconductor light emitting element 31 and its periphery. The volume of the liquid substance 37 to be dropped is approximately the same as the total volume of the main facing portion 37a and the sub-facing portion 37b. Specifically, the total volume of the liquid substance 37 to be dropped is slightly larger than the total volume of the main facing portion 37a and the sub-facing portion 37b.

[0092] Subsequently, in the third step, the light-transmitting member 35 is covered and bonded to the mounting substrate 32. At this time, as the light-transmitting member 35 approaches the main element surface 31a, the liquid substance 37 dropped on the main element surface 31a contacts the light-transmitting member 35 and then gradually moves toward the element side surface 31b side. The liquid substance 37 that has moved to the element side surface 31b side is in a state where the sub-facing portion 37b is held due to the capillary action between the element side surface 31b and the side wall portion 323 of the recess 321. In this way, the light source module 30 shown in FIG. 1 is completed.

[0093] In particular, at a temperature of 25°C, since the contact angle of the liquid substance 37 dropped on the main element surface 31a is within the above angle range, the state in which the main facing portion 37a is held can be maintained. Furthermore, at a temperature of 25°C, since the contact angle of the liquid substance 37 with respect to the element side surface 31b is within the above angle range, the state in which the sub-facing portion 37b is held can be maintained.

[0094] 8. Function and effect Next, the operation and effect of the light source module 30 of the present embodiment will be described in detail. According to the light source module 30 of the present embodiment, since the liquid substance 37 is filled in the space surrounded by the outer shape of the plurality of semiconductor light emitting elements 31, the mounting substrate 32, and the light transmissive member 35, the extraction efficiency of the ultraviolet light emitted by the plurality of semiconductor light emitting elements 31 can be improved. Since the substance filled in the space surrounded by the outer shape of the plurality of semiconductor light emitting elements 31, the mounting substrate 32, and the light transmissive member 35 is the liquid substance 37, the stress generated in the semiconductor light emitting element 31 is reduced even when the arrangement ratio of the light emitting elements 31 with respect to the mounting substrate 32 is high as compared with the case where the substance is a cured resin.

[0095] In the light source module 30 of the present embodiment, among the plurality of semiconductor light emitting elements 31, the adjacent semiconductor light emitting elements 31 are directly mounted on the mounting substrate 32 in a state where the element side surfaces 31b are in contact with each other. According to this, the stress generated in the element side surfaces 31b of the adjacent semiconductor light emitting elements 31 can be reduced.

[0096] In the light source module 30 of the present embodiment, since gas exists in the gap between the element side surfaces 31b of the adjacent semiconductor light emitting elements 31, the emission from the element side surface can be suppressed and the directivity can be improved.

[0097] In the light source module 30 of the present embodiment, the surface roughness Ra of the element side surface 31b is 0.1 nm or more and 100000 nm. According to this, the emission from the element side surface can be suppressed and the directivity can be improved.

[0098] In the light source module 30 of the present embodiment, the maximum gap between the element side surfaces 31b of the adjacent semiconductor light emitting elements 31 is 200000 nm or less. Thereby, the emission from the element side surface can be suppressed and the directivity can be improved.

[0099] In the light source module 30 of the present embodiment, since the contact angle of the liquid substance 37 is 10° or more, gas easily exists in the gap between the element side surfaces 31b of the adjacent semiconductor light emitting elements 31.

[0100] In the light source module 30 of the present embodiment, the liquid substance 37 is a fluorine-based inert liquid. Thereby, the extraction efficiency of the ultraviolet light emitted by the plurality of semiconductor light-emitting elements 31 can be effectively improved.

[0101] (Embodiment 2) In the above-described Embodiment 1, the plurality of semiconductor light-emitting elements 31 are arranged such that the element side surfaces 31b of adjacent semiconductor light-emitting elements 31 are in contact with each other. However, in the present Embodiment 2, as shown in FIG. 5, the plurality of semiconductor light-emitting elements 31 are arranged such that the element side surfaces 31b of adjacent semiconductor light-emitting elements 31 are separated by a predetermined distance.

[0102] The element side surfaces 31b of adjacent semiconductor light-emitting elements 31 are separated by a distance of 5.0 mm or less. The contact angle of the liquid substance 37 filled in the inner space (the space sealed by the light-transmitting member 35) of the concave portion 321 of the mounting substrate 32 is 50° or less.

[0103] Thereby, the liquid substance 37 is filled in the gap between the element side surfaces 31b of adjacent semiconductor light-emitting elements 31, and a state in which the sub-opposing portion 37b of the liquid substance 37 is held in the gap between the element side surfaces 31b of adjacent semiconductor light-emitting elements 31 can be maintained.

[0104] Since the sub-opposing portion 37b of the liquid substance 37 is filled in the region where the element side surfaces 31b of adjacent semiconductor light-emitting elements 31 face each other, among the ultraviolet light emitted from the active layer 31c of the semiconductor light-emitting element 31, the ultraviolet light output from the element side surfaces 31b of adjacent semiconductor light-emitting elements 31 is output from the light-transmitting member 35 through the sub-opposing portion 37b of the liquid substance 37.

[0105] Here, the liquid substance 37 is in contact with the adjacent element side surfaces 31b, and the liquid substance 37 is in contact with the light-transmitting member 35. Therefore, the emitted ultraviolet light is suppressed from being reflected at the element side surface 31b and is output from the light-transmitting member 35.

[0106] According to the light source module 30 of the present embodiment, among the plurality of semiconductor light emitting elements 31, adjacent semiconductor light emitting elements 31 are directly mounted on the mounting substrate 32 in a state where the element side surfaces 31b are separated from each other at an interval of 5.0 mm or less. According to this, ultraviolet light can also be extracted from the element side surfaces 31b of adjacent semiconductor light emitting elements 31.

[0107] According to the light source module 30 of the present embodiment, since the liquid substance 37 is filled between the element side surfaces 31b of adjacent semiconductor light emitting elements 31, the extraction efficiency of ultraviolet light from the element side surfaces 31b of adjacent semiconductor light emitting elements 31 can be improved.

[0108] According to the light source module 30 of the present embodiment, since the contact angle of the liquid substance 37 is 50° or less, the liquid substance 37 is easily filled between the element side surfaces 31b of adjacent semiconductor light emitting elements 31.

[0109] (Modification of Embodiment 2) In Embodiment 2, the liquid substance 37 is filled in the gap between the element side surfaces 31b of adjacent semiconductor light emitting elements 31, but gas (for example, air) may be present in at least a part of the gap between the element side surfaces 31b of adjacent semiconductor light emitting elements 31. The gas may be present in the entire gap between the element side surfaces 31b of adjacent semiconductor light emitting elements 31. The gas may be present only in a part of the gap between the element side surfaces 31b of adjacent semiconductor light emitting elements 31. That is, the gas and the liquid substance 37 may be mixed in the gap between the element side surfaces 31b of adjacent semiconductor light emitting elements 31. According to this, the emission from the element side surface can be suppressed and the directivity can be improved.

[0110] (Embodiment 3) 1. Outline of the configuration of the fluid sterilization device 2 FIG. 6 is a diagram schematically showing the configuration of the fluid sterilization device 2 in the present embodiment. As shown in FIG. 6, the fluid sterilization device 2 in the present embodiment has a flow path pipe 100 and a light source unit 110. Further, the light source unit 110 has a semiconductor light emitting element 141, a column portion 120, and a storage portion 130.

[0111] In the fluid sterilization device 2 of the present embodiment, fluid is flowed from the inlet 101 of the flow path tube 100 into the flow path space inside the flow path tube 100, and the fluid is irradiated with ultraviolet light from the light source unit 110 to sterilize the fluid, and the sterilized fluid is discharged from the outlet 102. The fluid to be sterilized may be a gas or a liquid, and may be a mixture of a gas and a liquid, a mixture of a gas and a powdery solid, etc., as long as it has fluidity. In the case of a liquid, for example, water, oil, alcohol, a solution using these as solvents, etc.

[0112] 2. Details of each component of the fluid sterilization device 2 Next, each component of the fluid sterilization device 2 will be described in detail.

[0113] 2-1. Configuration of the flow path tube 100 The flow path tube 100 is cylindrical and has a cylindrical space inside. This space is the flow path space through which the fluid to be sterilized flows. The material of the flow path tube 100 is a metal such as stainless steel, titanium, aluminum, iron, etc., a resin material such as polyvinyl chloride, polyethylene, or PTFE (polytetrafluoroethylene), or a glass such as quartz glass.

[0114] Stainless steel, titanium, iron, and polyvinyl chloride are materials with a high absorption rate of ultraviolet light and a low reflectivity of ultraviolet light compared to materials with a high reflectivity of ultraviolet light such as aluminum or PTFE (polytetrafluoroethylene). Stainless steel and titanium are materials with high corrosion resistance to seawater. Glass is, for example, quartz glass, soda-lime glass, borosilicate glass, lead glass, etc., and is a material that is transparent to ultraviolet light and has a low reflectivity of ultraviolet light. In the case of a material with a low reflectivity of ultraviolet light as the material of the flow path tube 100, for example, the reflectivity of ultraviolet light on the surface in contact with the fluid to be sterilized is 35% or less.

[0115] One light source unit 110 is provided at each of both ends of the flow path tube 100. Further, an inlet 101 is provided on the side wall of one (left side in FIG. 6) end side in the axial direction of the flow path tube 100, and an outlet 102 is provided on the side wall of the other (right side in FIG. 6) end side. Hereinafter, the end on the inlet 101 side of the flow path tube 100 is referred to as the first end, and the end on the outlet 102 side of the flow path tube 100 is referred to as the second end.

[0116] Of the light source units 110 arranged at both ends of the flow path tube 100, the light source unit arranged closer to the inlet 101 is the first light source unit 110A, and the light source unit arranged closer to the outlet is the second light source unit 110B. Hereinafter, the first light source unit 110A and the second light source unit 110B are simply referred to as the light source unit 110 without distinguishing their names.

[0117] FIG. 7(a) is a diagram showing the position of the inlet 101, and FIG. 7(b) is a diagram showing the position of the outlet 102. FIGS. 7(a) and 7(b) are cross-sectional views of a cross-section cut along a plane perpendicular to the central axis of the flow path tube 100, viewed from the first end side toward the second end side.

[0118] As shown in FIG. 7(a), the inlet 101 is arranged such that the inflow direction of the fluid flowing in from the inlet 101 is offset with respect to the center O of the flow path tube 100. That is, the central axis L1 of the inlet 101 is displaced so as not to pass through the center O of the flow path tube 100. By offsetting the position of the inlet 101 in this way, a spiral flow can be formed in the flow path space in the flow path tube 100 as shown in FIG. 8. The tangential direction of the spiral flow on the central axis L1 of the inlet 101 is the direction of the central axis L1 of the inlet 101.

[0119] The outlet 102 is also arranged such that the outflow direction is offset with respect to the center O of the flow path tube 100, as shown in FIG. 7(b). That is, the central axis L2 of the outlet 102 is displaced so as not to pass through the center O of the flow path tube 100. As a result, a spiral flow can be maintained also on the outlet 102 side, and the tangential direction of the spiral flow on the central axis L2 of the outlet 102 is the direction of the central axis L2 of the outlet 102.

[0120] 2-2. Configuration of Light Source Unit 110 The light source unit 110 includes a column portion 120, a storage portion 130, and a semiconductor light emitting element 141. The storage portion 130 houses the semiconductor light emitting element 141. Hereinafter, the light source unit 110 provided on the first end side will be described, but the light source unit 110 provided on the second end side has the same configuration.

[0121] As shown in FIG. 6, the column portion 120 protrudes in the axial direction of the flow path tube 100 from the first end side to the second end side of the flow path tube 100 and has a frustum-shaped portion. The central axis of the column portion 120 coincides with the central axis of the flow path tube 100. That is, the central axis of the column portion 120 is arranged coaxially with the central axis of the flow path tube 100.

[0122] The inclination angle (angle with respect to the bottom surface) of the side surface of the frustum is, for example, 30 to 70°. The end portion on the larger diameter side of the column portion 120 is connected to the first end of the flow path tube 100, and the end portion on the smaller diameter side is connected to the storage portion 130.

[0123] The shape of the column portion 120 is not limited to a frustum shape, and any shape may be used as long as it becomes thinner toward the second end side. A stepwise thinning shape may be used, but a continuously thinning shape is preferred. For example, a frustum-shaped pyramid may be used. However, a frustum shape is preferred for forming a spiral flow. Also, the entire column portion 120 does not have to be a frustum, and a part may be a frustum and the other part may be a cylinder. For example, as shown in FIG. 6, the tip side portion of the column portion 120 connected to the storage portion 130 may be cylindrical, and the root side portion connected to the first end of the flow path tube 100 may be frustum-shaped.

[0124] As shown in FIG. 9, the storage portion 130 that houses the semiconductor light emitting element 141 includes a glass plate 132, a pedestal portion 133, and a mounting substrate 135.

[0125] The pedestal portion 133 is a bottomed cylindrical member with an open front end surface, and the bottom surface is connected to the tip of the column portion 120. The central axis of the pedestal portion 133 coincides with the central axis of the column portion 120. That is, the central axis of the pedestal portion 133 is arranged coaxially with the central axis of the column portion 120. As described above, the central axis of the column portion 120 is arranged coaxially with the central axis of the flow path pipe 100. Therefore, the central axis of the pedestal portion 133 is also arranged coaxially with the central axis of the flow path pipe 100.

[0126] In the internal space of the pedestal portion 133, a mounting substrate 135 is arranged at the bottom, and a semiconductor light emitting element 141 is mounted on the mounting substrate 135. A glass plate 132 is provided on the front end surface of the pedestal portion 133, sealing the internal space of the pedestal portion 133. The glass plate 132 is a material that transmits ultraviolet light from the semiconductor light emitting element 141, such as quartz or sapphire. By providing a photocatalyst film that transmits ultraviolet light on the surface of the glass plate 132, it is possible to suppress the growth of germs on the glass plate 132 and prevent contamination by organic substances. The glass plate 132 is not limited to a flat plate and may be lens-shaped. For example, it may be a TIR lens, a fly-eye lens, a Fresnel lens, or the like.

[0127] The pedestal portion 133 is formed so as to extend radially outward from the tip of the column portion 120 over the entire circumference of the tip of the column portion 120. That is, the outer diameter of the pedestal portion 133 is larger than the outer diameter of the tip of the column portion 120. Therefore, the bottom surface of the pedestal portion 133 is exposed to the flow path space except for the region connected to the column portion 120.

[0128] A peripheral wall 136 protruding toward the first end side is formed at the outer edge portion of the bottom surface of the pedestal portion 133. As a result, a recessed portion 134 that is recessed more than the peripheral wall 136 is formed in the portion of the bottom surface of the pedestal portion 133 surrounded by the peripheral wall 136. The recessed portion 134 is provided to retain fluid as much as possible near the bottom surface of the pedestal portion 133. The pedestal portion 133 can be cooled by the fluid that stays near the bottom surface of the pedestal portion 133. That is, the heat-generating semiconductor light emitting element 141 can be cooled via the pedestal portion 133.

[0129] In this embodiment, the peripheral wall 136 is provided over the entire circumference of the bottom surface of the pedestal portion 133, but it may be provided only on a part of the bottom surface of the pedestal portion 133. By providing the peripheral wall 136 only on a part of the bottom surface of the pedestal portion 133, the formation of an air pocket in the recess 134 can be suppressed and the cooling efficiency can be improved.

[0130] The peripheral wall 136 is preferably provided outside the semiconductor light-emitting element 141 when viewed in the central axis direction of the flow path tube 100. That is, when viewed in the central axis direction of the flow path tube 100, it is preferable that the recess 134 is located at a position overlapping the semiconductor light-emitting element 141. The fluid staying near the bottom surface of the pedestal portion 133 can cool the pedestal portion 133 more efficiently. That is, the heat-generating semiconductor light-emitting element 141 can be cooled more efficiently via the pedestal portion 133.

[0131] In this embodiment, the pedestal portion 133 is a bottomed cylindrical member, but any member having a bottomed cylindrical shape may be used. For example, it may be a bottomed rectangular tube-shaped (polygonal box-shaped) member. However, from the viewpoint of generating a spiral flow, it is preferable to use a bottomed cylindrical shape as in this embodiment.

[0132] The materials of the column portion 120 and the pedestal portion 133 are preferably metal materials with high thermal conductivity such as aluminum. Titanium may be used as the material of the column portion 120 and the pedestal portion 133, and the surface may be oxidized to form a photocatalytic film. According to this, the propagation of various bacteria in the column portion 120 and the pedestal portion 133 can be suppressed.

[0133] The semiconductor light-emitting element 141 is directly mounted on the mounting substrate 135. A plurality of semiconductor light-emitting elements 141 may be mounted on one mounting substrate 135, and three are mounted in FIGS. 6 and 9.

[0134] The semiconductor light-emitting element 141 is a light-emitting element that emits ultraviolet light. The wavelength of the ultraviolet light is preferably 250 to 285 nm, which is a wavelength with high sterilization efficiency. The configuration of the semiconductor light-emitting element 141 is not limited, and it may be any of a face-up type, a flip-chip type, and a through-conduction type.

[0135] The mounting substrate 135 is a substrate on which the semiconductor light-emitting element 141 is mounted. In this embodiment, the mounting substrate 135 is formed of aluminum. The mounting substrate 135 may be a glass epoxy substrate such as FR-4 or CEM3, or a flexible substrate made of polyimide or the like.

[0136] As shown in FIG. 9, the mounting surface of the mounting substrate 135 on which the semiconductor light-emitting element 141 is mounted is formed in a planar shape perpendicular to the central axis of the pedestal portion 133. In this embodiment, on the mounting surface of the mounting substrate 135, the three semiconductor light-emitting elements 141 are arranged such that the side surfaces of adjacent semiconductor light-emitting elements 141 abut against each other.

[0137] A circuit forming member (not shown) electrically connected to the semiconductor light-emitting element 141 is mounted on the mounting substrate 135. The circuit forming member is a drive circuit for causing the semiconductor light-emitting element 141 to emit light, a connector header for connecting the drive circuit and the power cable, or the like. As other electronic components (not shown), a thermistor for measuring the temperature of the mounting substrate 135, a connector header for connecting the thermistor to the power cable, and the like are provided on the mounting substrate 135.

[0138] As shown in FIG. 9, a liquid substance 137 is enclosed in the storage portion 130. The liquid substance 137 is filled in the inner space of the storage portion 130 (the space sealed by the glass plate 132). The detailed configurations of the semiconductor light-emitting element 141 and the liquid substance 137 are the same as the detailed configurations of the semiconductor light-emitting element 31 and the liquid substance 37 in the above-described Embodiment 1. Therefore, the description of the detailed configurations of the semiconductor light-emitting element 141 and the liquid substance 137 in this Embodiment 2 is omitted.

[0139] 2-3. Optical axis 144 of semiconductor light-emitting element 141 The optical axis 144 of the semiconductor light-emitting element 141 is, in the ultraviolet light emitted by the semiconductor light-emitting element 141, the axis in the stacking direction of the semiconductor layers for emitting ultraviolet light, that is, the axis perpendicular to the main surface of the element substrate on which the semiconductor layers are stacked. The optical axis 144 is, for example, the axis located at the center in the irradiation range of the ultraviolet light of the semiconductor light-emitting element 141 having a predetermined light distribution characteristic.

[0140] The optical axis 144 may be a virtual line extending in the direction in which the luminous intensity of the ultraviolet light is maximized from the semiconductor light-emitting element 141 in the irradiation range of the ultraviolet light, but is not limited to this depending on the configuration of the semiconductor light-emitting element 141. In the present embodiment, the optical axis 144 of the semiconductor light-emitting element 141 is on the perpendicular line with respect to the portion of the mounting surface on which the semiconductor light-emitting element 141 is mounted.

[0141] As described above, the mounting surface of the mounting substrate 135 is formed in a planar shape perpendicular to the central axis of the pedestal portion 133. Therefore, the optical axis 144 of the semiconductor light-emitting element 141 is parallel to the central axis of the pedestal portion 133.

[0142] As described above, the central axis of the pedestal portion 133 is arranged coaxially with the central axis of the flow path tube 100. Therefore, the optical axis 144 of the semiconductor light-emitting element 141 is parallel to the central axis of the flow path tube 100.

[0143] 3. Regarding the flow path of the fluid Next, the flow path of the fluid in the flow path space will be described. FIG. 8 is a diagram schematically showing the flow path of the fluid in the vicinity of the first end of the flow path tube 100. As shown in FIG. 8, the fluid that has entered the flow path space in the flow path tube 100 from the inlet 101 hits the side surface of the frustum-shaped portion of the column portion 120, but is reflected in the axial direction due to the inclination of the side surface, and a flow toward the storage portion 130 is formed. Therefore, the fluid can be efficiently brought into contact with the storage portion 130, and the cooling efficiency can be improved.

[0144] Since the outer diameter of the pedestal portion 133 is larger than the outer diameter of the tip of the column portion 120, fluid can be brought into contact with the bottom surface of the pedestal portion 133 (the left - hand side surface in FIG. 8). Therefore, the pedestal portion 133 can be efficiently cooled.

[0145] Since a peripheral wall 136 is provided on the bottom surface of the pedestal portion 133 and there is a recess 134 surrounded by the peripheral wall 136, fluid is likely to stay on the back surface of the pedestal portion 133. Therefore, heat can be efficiently conducted from the bottom surface of the pedestal portion 133 to the fluid, and the cooling efficiency can be improved.

[0146] Since the inlet 101 is offset, as shown in FIG. 8, a flow that swirls around the column portion 120 is formed. Since the column portion 120 is shaped to become thinner from the first end side toward the second end side, the fluid flows axially from the first end side toward the second end side while swirling around the column portion 120. Therefore, a spiral flow is formed in the flow - path space. By making it a spiral flow, the residence time of the fluid in the flow - path space becomes longer and the irradiation time of ultraviolet light on the fluid becomes longer, so the sterilization efficiency can be improved.

[0147] In the light - source portion 110 on the outlet 102 side, since the column portion 120 is shaped to become thinner from the second end side toward the first end side, the fluid flowing from the first end side toward the second end side can be reflected in the radial direction of the flow - path tube 100 by the column portion 120. Therefore, the residence time of the fluid can be lengthened in the vicinity of the storage portion 130 on the outlet 102 side, so the storage portion 130 can be efficiently cooled.

[0148] 4. Operational Effects Similar to the above - described Embodiment 1, since the liquid substance 137 is enclosed in the storage portion 130, the extraction efficiency of ultraviolet light can be improved in the same manner as in Embodiment 1.

[0149] (Modification of Embodiment 3) In the fluid sterilization device 2 according to Embodiment 3, the light source units 110 are provided on each of the inlet 101 side and the outlet 102 side. However, when the flow path tube 100 is short, etc., the light source unit 110 may be provided only on the inlet 101 side. In this case, a reflecting member that reflects ultraviolet light is arranged on the end face on the second end side, and the sterilization efficiency can be improved by irradiating the fluid with the reflected light of the ultraviolet light by this reflecting member. Further, the light source unit 110 may be provided only on the outlet 102 side. Also in this case, the sterilization efficiency can be improved by providing a reflecting member on the end face on the first end side. As the reflecting member, PTFE, SUS, Ti, etc. can be used.

[0150] (Embodiment 4) In the above Embodiment 3, on the mounting surface of the mounting substrate 135, the three semiconductor light emitting elements 141 are arranged such that the side surfaces of the adjacent semiconductor light emitting elements 141 abut against each other. On the other hand, in this Embodiment 4, as shown in FIG. 8, on the mounting surface of the mounting substrate 135, the three semiconductor light emitting elements 141 are arranged with a predetermined interval between the side surfaces of the adjacent semiconductor light emitting elements 141.

[0151] The storage unit 130 is filled with a liquid substance 137. The liquid substance 137 is filled in the inner space of the storage unit 130 (the space sealed by the glass plate 132). The detailed configurations of the semiconductor light emitting element 141 and the liquid substance 137 are the same as the detailed configurations of the semiconductor light emitting element 31 and the liquid substance 37 in the above Embodiment 2. Therefore, the description of the detailed configurations of the semiconductor light emitting element 141 and the liquid substance 137 in this Embodiment 4 is omitted.

[0152] Similar to the above Embodiment 2, the storage unit 130 is filled with the liquid substance 137, and the liquid substance 137 also exists between the side surfaces of the adjacent semiconductor light emitting elements 141. Therefore, similar to the above Embodiment 2, the extraction efficiency of ultraviolet light can be improved.

[0153] (Other Modification Forms) In the above embodiment, the sterilization of liquids has been described. However, any fluid can be sterilized, including gases, mixtures of gases and liquids, mixtures of gases and powdered solids, etc.

[0154] The present invention is not limited to the above embodiment, and can be applied to various embodiments without departing from the gist thereof.

Explanation of Reference Numerals

[0155] 31 Semiconductor light-emitting element 31b Element side surface (side surface of the semiconductor light-emitting element) 32 Mounting substrate 35 Translucent member 37 Liquid substance

Claims

1. A plurality of semiconductor light-emitting elements that emit ultraviolet light for sterilizing a fluid; A mounting substrate on which the plurality of semiconductor light-emitting elements are directly mounted; A light-transmitting member that transmits the ultraviolet light and separates the plurality of semiconductor light-emitting elements and the mounting substrate from the fluid; A light source module comprising a liquid substance filled in a space surrounded by the outer shapes of the plurality of semiconductor light-emitting elements, the mounting substrate, and the light-transmitting member.

2. The light source module according to claim 1, wherein adjacent semiconductor light-emitting elements among the plurality of semiconductor light-emitting elements are directly mounted on the mounting substrate in a state where their side surfaces are in contact with each other.

3. The light source module according to claim 2, wherein a gas exists in a gap between the side surfaces of the adjacent semiconductor light-emitting elements.

4. The light source module according to claim 3, wherein the surface roughness Ra of the side surface is 0.1 nm or more and 100,000 nm or less.

5. The light source module according to claim 3, wherein a maximum gap between the side surfaces of the adjacent semiconductor light-emitting elements is 200,000 nm or less.

6. The light source module according to claim 3, wherein a contact angle of the liquid substance is 10° or more.

7. The light source module according to claim 1, wherein adjacent semiconductor light-emitting elements among the plurality of semiconductor light-emitting elements are directly mounted on the mounting substrate in a state where their side surfaces are separated by a distance of 5.0 mm or less.

8. The light source module according to claim 7, wherein the liquid substance is filled in a gap between the side surfaces of the adjacent semiconductor light-emitting elements.

9. The light source module according to claim 7, wherein a gas exists in a gap between the side surfaces of the adjacent semiconductor light-emitting elements.

10. The contact angle of the liquid substance is 50° or less. The light source module according to claim 7 or 8.

11. The liquid substance is a fluorine-based inert liquid. The light source module according to claim 1.

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