JP5220687B2 - Lighting device and plant cultivation system for plant cultivation - Google Patents

Description

  The present invention relates to a lighting device for plant cultivation and a plant cultivation system using the same.

In recent years, plant factories and vegetable factories that produce crops by controlling all conditions that affect plant growth, such as light, temperature, humidity, and carbon dioxide concentration in the cultivation environment, as an agricultural environment that is not affected by changes in natural conditions Etc. are being put to practical use.
These plant factories include a completely artificial light type and a combination type of sunlight, and it is essential to install an illumination device that emits artificial light. And it is required from a lighting device to irradiate a plant with red and blue light. A semiconductor light emitting element (LED: Light Emitting Diode) has been used as a light source of these lighting devices.
The environment of a cultivation room for plant cultivation such as a plant factory is maintained at a predetermined temperature and humidity. Therefore, the heat generated from the lighting device installed there is not preferable because it affects the temperature management of the cultivation room. Furthermore, since the cultivation room is generally high temperature and high humidity, if the lighting device is installed there, it is not preferable as an environment where the lighting device is installed.

Patent Document 1 describes a plant cultivation apparatus in which a light source composed of a panel-shaped optical semiconductor unit provided with a forced cooling device using a thermal refrigerant is installed close to a plant cultivation surface.
In Patent Document 2, in order to increase the durability of a lighting panel for plant cultivation even in a high humidity environment, a base, a substrate made of a thin metal plate closely attached to the base, and a large number of substrates arranged on the substrate are disclosed. The space is provided with a light emitting diode, a cover disposed with a space between the base, and a sealing material interposed between the base and the cover to maintain the space airtight with respect to the outside. A lighting panel for plant cultivation in which dry air is filled and a desiccant is contained in a frame material is described.
In Patent Document 3, in order to promote the heat radiation of the semiconductor light emitting element of the semiconductor light emitting lighting device for plant cultivation and to increase the brightness by applying a large current, it is possible to pass cooling water on the upper side and to energize the inside. A semiconductor light-emitting illuminating device having a metal wall and a light source unit attached to the lower part of the metal wall is described.

JP-A-9-98665 JP 2000-207933 A JP 2003-110143 A

Conventionally, in plant cultivation using a semiconductor light emitting device as a light source, a current exceeding the rated current has been applied in order to obtain a photon density necessary for plant growth. Accordingly, the amount of heat generated by the semiconductor light emitting element has increased, and the junction temperature of the semiconductor light emitting element has increased. The increase in the temperature of the semiconductor light emitting device has a problem in that the light emitting efficiency of the semiconductor light emitting device itself decreases and the resin material such as epoxy resin that is a peripheral member of the semiconductor light emitting device causes yellowing. In order to solve this, it is effective to water-cool the semiconductor light-emitting element, but it causes condensation and moisture absorption on the semiconductor light-emitting element and peripheral members of the semiconductor light-emitting element, thereby causing deterioration and non-lighting of the semiconductor light-emitting element itself. The problem was that light emission intensity decreased due to oxidation of surrounding silver plating, solder, and copper foil, and that lighting did not proceed rapidly. In particular, the red light-emitting device having a peak wavelength of 660 nm is a Ga _1-x Al _x As-based compound semiconductor light-emitting device having a high Al composition, so that oxygen is easily bonded to Al atoms in a high-humidity environment. It itself changed rapidly, the light emission intensity decreased rapidly, and finally turned off.
An object of the present invention is to solve problems caused by condensation and moisture absorption when a semiconductor light emitting device is efficiently cooled by a coolant such as water, and is used for plant cultivation using a semiconductor light emitting device having a long life and maintaining high efficiency as a light source. It is providing the lighting apparatus of this and a plant cultivation system using the same.

For such an object, a lighting device to which the present invention is applied has a plurality of light-emitting elements and a light-transmitting window that transmits light emitted from the light-emitting elements, and is provided so as to cover the light-emitting elements. A heat dissipating substrate disposed inside the housing and dissipating heat generated by the light emitting element by conduction, and a refrigerant conduit attached to the heat dissipating substrate and serving as a refrigerant flow path. The lighting device for plant cultivation is configured to include a refrigerant conduit inside and to suppress the inflow of outside air inside the housing.
In such a plant cultivation lighting device, the housing may be configured such that the inside of the housing is filled with dry air or dry nitrogen.
Further, the lighting device for plant cultivation further includes a connecting means for connecting the refrigerant conduit and the adjacent refrigerant conduit provided in the adjacent lighting device, and forming a refrigerant flow path between the adjacent refrigerant conduit and the refrigerant conduit. Can be characterized.

On the other hand, the case has a long box shape, and one surface in the longitudinal direction constitutes a light-transmitting window portion, and the other three surfaces in the longitudinal direction constitute a continuous exterior portion, The remaining two surfaces may be featured as side portions.
The exterior part may be manufactured by extrusion molding of aluminum or aluminum alloy.
The heat dissipating substrate has a portion into which the refrigerant conduit is inserted, and is manufactured by extrusion molding of aluminum or an aluminum alloy, and is configured integrally with the inserted refrigerant conduit.
The light emitting device is installed in the light emitting device package, the light emitting device package is fixed to the circuit board, and the circuit board is fixed to the heat dissipation board.
The light emitting element may be directly attached to a metal base portion of a metal base circuit board, and the circuit board may be fixed to the heat dissipation board.
The light emitting element may include a light emitting element having an emission peak wavelength of 400 to 500 nm and a light emitting element having an emission peak wavelength of 655 to 675 nm.
The light-emitting element includes a compound semiconductor layer including at least a pn junction type light-emitting portion and a strain adjustment layer stacked on the light-emitting portion, and the light-emitting portion has a composition formula (Al _X Ga _1-X ) _Y In _{1-1. It} has a laminated structure of a strained light emitting layer made of YP (0 ≦ X ≦ 0.1, 0.37 ≦ Y ≦ 0.46) and a barrier layer, and the strain adjusting layer is transparent to the light emission wavelength. And having a lattice constant smaller than that of the strained light emitting layer and the barrier layer.
Further, the lighting device for plant cultivation to which the present invention is applied is characterized in that it further includes a reflector for setting the direction of light of the light emitting element between the light emitting element and the translucent window. it can.

  From another viewpoint, the plant cultivation system to which the present invention is applied has a plurality of light emitting elements and a light-transmitting window that transmits light emitted from the light emitting elements, and is provided so as to cover the light emitting elements. An adjacent casing, a heat dissipating board disposed inside the casing and dissipating heat generated by the light emitting element by conduction, and a refrigerant conduit attached to the heat dissipating board and serving as a refrigerant flow path. A plurality of plant cultivation lighting devices that connect the conduits to each other to form a refrigerant flow path, a plurality of plant cultivation lighting devices, a refrigerant supply unit that supplies refrigerant to the coupled refrigerant conduits, and a plurality The illumination control part which controls lighting and extinction of the light emitting element of the illuminating device for plant cultivation of this can be provided, It can be characterized by the above-mentioned.

  ADVANTAGE OF THE INVENTION According to this invention, it solves the malfunction by condensation and moisture absorption at the time of cooling a semiconductor light-emitting device efficiently with refrigerant | coolants, such as water, For plant cultivation which uses a semiconductor light-emitting device with a long lifetime and high efficiency as a light source It is possible to provide a lighting device and a plant cultivation system using the same.

It is a figure which shows an example of the plant cultivation system to which this Embodiment is applied. It is a figure which shows an example of the external shape of the illuminating device to which 1st Embodiment is applied. It is a figure explaining an example of the 1st piping coupler and the 2nd piping coupler. It is a figure explaining an example of the inside of an illuminating device. It is a figure explaining an example of the composition of the light emitting element package used in a 1st embodiment. It is sectional drawing explaining an example of a structure of the semiconductor light-emitting device of the blue light emission used in this Embodiment. It is a top view of the semiconductor light emitting element of blue light emission. It is sectional drawing explaining an example of a structure of the semiconductor light emitting element of the red light emission used in this Embodiment. It is a top view of a semiconductor light emitting element emitting red light. It is sectional drawing of an example of the illuminating device to which 2nd Embodiment is applied. It is a top view for demonstrating an example of the connection relation between the connection wiring provided in the chip-on-board type circuit board, and the semiconductor light emitting element. It is a figure which further demonstrates the chip-on-board-type circuit board which mounted the semiconductor light-emitting device directly.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
(First embodiment)
FIG. 1 is a diagram illustrating an example of a plant cultivation system 1 to which the present exemplary embodiment is applied.
The plant cultivation system 1 is installed in the cultivation room 60 and is installed in the cultivation room 60 in the vicinity of the cultivation container 50 and irradiates light to the plant to be cultivated. And a plurality of lighting devices 10. The lighting device 10 is provided with a refrigerant conduit 25. And the some illuminating device 10 is connected by the connection means. That is, the refrigerant conduit 25 of a certain lighting device 10 and the refrigerant conduit 25 (adjacent refrigerant conduit) of the lighting device 10 adjacent thereto are connected to form a refrigerant flow path.
Furthermore, the plant cultivation system 1 is installed outside the cultivation room 60 and controls the lighting control unit 30 to turn on / off the illumination of the lighting device 10, and is also installed outside the cultivation room 60 and water that cools the lighting device 10. And a refrigerant supply unit 40 that supplies the refrigerant conduit 25 to the refrigerant conduit 25.

The cultivation room 60 may have any configuration as long as the environment can control temperature, humidity, daylighting, and the like. The cultivation room 60 may be an environment in which the circulation of light and air from the outside is blocked, or may be an environment having a window that allows the circulation of light and air from the outside.
The cultivation container 50 may be a container in which soil is put and a plant is grown. Moreover, the container holding the nutrient solution which nourishes a plant like hydroponics may be sufficient.
And although not shown in FIG. 1, the plant cultivation system 1 may be provided with the watering part for watering the plant of the cultivation container 50. FIG. Moreover, when a plant is hydroponics, you may provide the nutrient solution supply part which supplies or circulates the nutrient solution for hydroponics.

As will be described later, the lighting device 10 includes a plurality of semiconductor light emitting elements as light emitting elements (for example, a plurality of semiconductor light emitting elements of the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b in the light emitting element package 21 of FIG. 5 described later). Element is housed). In this case, the light generated by the plurality of semiconductor light emitting elements is irradiated to the plant grown in the cultivation container 50. For this reason, each illuminating device 10 is provided with the illumination control wiring 31 which supplies the electric power for light emission to a semiconductor light emitting element, and controls lighting / light extinction of a semiconductor light emitting element. These illumination control wirings 31 are connected to the illumination control unit 30.
Each lighting control wiring 31 may be connected so that all the semiconductor light emitting elements in the lighting device 10 to which the lighting control wiring 31 is connected are turned on / off simultaneously. Further, the semiconductor light emitting elements in one lighting device 10 may be grouped according to, for example, emission color, and connected so that lighting / extinguishing can be controlled for each group.

  The illumination control unit 30 may be anything that can control the lighting device 10 to be turned on / off. Therefore, it may be a switch array in which switches for turning on / off power supply are arranged for each lighting device 10. The on / off of the switch array may be controlled by a computer or the like. The illumination control unit 30 only needs to be capable of setting and controlling the applied current value of a semiconductor light emitting element such as red or blue. Further, as the pulse lighting, it is desirable to control the cycle and duty of semiconductor light emitting elements such as red and blue. What controls the lighting time and non-lighting time with a timer is desirable.

Further, as shown by the broken line in FIG. 1, each lighting device 10 discharges heat generated from the semiconductor light-emitting elements to the outside of the cultivation room 60, so that a refrigerant conduit provided through the lighting device 10 in the longitudinal direction. 25. And each illuminating device 10 is mutually connected by the piping coupler (The 1st piping coupler 16 and the 2nd piping coupler 17 of FIG. 2 mentioned later) connected to the edge part of the refrigerant | coolant conduit | pipe 25. As shown in FIG. Two ends of the refrigerant conduit 25 that are not connected to the other lighting devices 10 are connected to the refrigerant supply unit 40 via the refrigerant pipe 41. Thus, since the refrigerant | coolant conduit | pipe 25 becomes a part of conduit | pipe connected to one through the refrigerant | coolant supply part 40, a liquid (refrigerant) can be circulated.
The refrigerant supply unit 40 controls the refrigerant to circulate through the plurality of lighting devices 10 (the direction in which the refrigerant flows is indicated by an arrow). The refrigerant supply unit 40 may be a pump driven by a motor, for example. And the electric power supply to a motor may be interlocked with the illumination control part 30 so that a refrigerant may be supplied when the semiconductor light emitting element is turned on.

In addition, although the case where all the illuminating devices 10 are connected in series is shown in FIG. 1, a plurality of rows of illuminating devices 10 connected in series may be provided in parallel. Moreover, you may mix a serial part and a parallel part. That is, it is only necessary that the refrigerant supply unit 40 cools the lighting device 10 by flowing the refrigerant so as to circulate through the refrigerant conduit 25 of the lighting device 10, and discharges the heat generated by the semiconductor light emitting element to the outside of the cultivation room 60.
In addition, in the illuminating device 10 of FIG. 1, in order to clarify the refrigerant | coolant flow in the plant cultivation system 1, the refrigerant | coolant conduit | pipe 25 in the illuminating device 10 was shown with the broken line, but in the illuminating device 10 so that it may mention later, In addition to the refrigerant conduit 25, a light emitting device package (a light emitting device package 21 in FIG. 5 described later) and the like are included.

FIG. 2 is a diagram illustrating an example of the outer shape of the illumination device 10 to which the present exemplary embodiment is applied. 2A is a top view, FIG. 2B is a bottom view, FIG. 2C is a left side view, and FIG. 2D is a right side view.
The illuminating device 10 includes a U-shaped exterior cover 11 as an example of an exterior part, a transparent cover 12 as an example of a translucent window part provided so as to cover an open part of the U-shape, and a left side. The 1st side cover 13 as an example of the side part provided in a surface, and the 2nd side cover 14 as an example of the side part provided in a right side are provided.
The first side cover 13 and the second side cover 14 are provided so as to cover both ends of the exterior cover 11 where the transparent cover 12 is attached.
That is, the outer shape of the lighting device 10 has a box shape surrounded by the exterior cover 11, the transparent cover 12, the first side cover 13, and the second side cover 14. As the box shape, a long box shape is preferably used in the use environment. However, in the present invention, the box shape is not particularly limited. The exterior cover 11, the transparent cover 12, the first side cover 13, and the second side cover 14 constitute a housing of the lighting device 10. The inside of the housing formed by these covers is referred to as the inside or inside of the lighting device 10, and the outside of the housing is referred to as the outside or outside of the lighting device 10.

On the outside of the first side cover 13 provided on the left side surface of the lighting device 10, a female pipe as an example of a connecting means connected to the refrigerant conduit 25 inside the lighting device 10 via a pipe joint 15. A second pipe coupler 17 as a member is provided.
A first pipe coupler 16, which is a male pipe member as an example of a connecting means connected to the refrigerant conduit 25 via a pipe joint 15, is provided outside the second side cover 14. That is, the first pipe coupler 16 and the second pipe coupler 17 are provided at positions facing the housing of the lighting device 10.
Further, the illumination control wiring 31 is extended from the second side cover 14 to the outside. For the illumination control wiring 31, a covering cord that can withstand a high temperature and high humidity environment in the cultivation room 60 is selected.

The exterior cover 11 can be made of any material as long as it provides rigidity to the lighting device 10 to prevent deformation. For example, metal materials such as aluminum (Al), stainless steel (SUS), copper (Cu), and titanium (Ti), and plastic materials such as ABS resin can be used. Among these, an extruded product made of Al or aluminum alloy, which is excellent in terms of weight and cost, is preferably used. In this case, the surface is more preferably anodized to prevent Al corrosion. Further, from the viewpoint of increasing the reflectivity and effective use of light, it is more preferable that the alumite processing is a white anodized or a clear coating thereon.
The transparent cover 12 can be made of any material as long as it efficiently transmits the light emission wavelength of the semiconductor light emitting element provided in the lighting device 10. The transparent cover 12 is preferably glass, for example. Further, acrylic resins such as acrylic acid ester, methacrylic acid ester polymer, polymethyl methacrylate resin (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), and the like can be suitably used. Furthermore, it is more preferable that an antireflection film for the emission wavelength of the semiconductor light emitting element is provided inside the illumination device 10 of the transparent cover 12.

  The first side cover 13 and the second side cover 14 can be made of any material as long as it provides rigidity to the lighting device 10 and prevents deformation, similarly to the exterior cover 11. That is, the first side cover 13 may be any one that can suppress deformation even when the refrigerant conduit 25 and the second pipe coupler 17 are connected with the first side cover 13 interposed therebetween. Similarly, the second side cover 14 only needs to be able to suppress deformation even when the refrigerant conduit 25 and the first pipe coupler 16 are connected with the second side cover 14 interposed therebetween. For these, for example, a metal material such as Al, SUS, Cu, Ti, and Mo, or a plastic material such as ABS can be used. Al die-casting which is superior in terms of weight may be used. And it is preferable that the 1st side cover 13 and the 2nd side cover 14 are provided with the dent so that the edge part of the exterior cover 11 and the transparent cover 12 can be inserted.

The lighting device 10 is filled with dry air, dry nitrogen, and the like, and the exterior cover 11, the transparent cover 12, the first cover 1, and the like so that air (outside air) containing moisture from the outside does not enter the lighting device 10. It is preferable that a portion serving as a boundary between the side cover 13 and the second side cover 14 is sealed with a filler.
By doing in this way, from the environment of high temperature and high humidity in the cultivation room 60, the deterioration of the semiconductor light emitting element and the circuit board on which the semiconductor light emitting element described later is mounted (the circuit board 22 of FIG. 4B described later). Copper foil, silver plating on copper foil, corrosion of solder, etc. can be suppressed.
A caulking material such as silicone can be used as the filler.

FIG. 3 is a diagram illustrating an example of the first pipe coupler 16 and the second pipe coupler 17. In the plant cultivation system 1 to which the present exemplary embodiment is applied, as illustrated in FIG. 1, the plurality of lighting devices 10 are connected by fitting the first pipe coupler 16 and the second pipe coupler 17 together. .
FIG. 3 shows a state in which the first pipe coupler 16 and the second pipe coupler 17 are fitted.
Both the first pipe coupler 16 and the second pipe coupler 17 are rotationally symmetric bodies. Therefore, the upper side of the first pipe coupler 16 and the second pipe coupler 17 shown in FIG. 3 shows a cross section in a plane including a symmetrical axis. The lower side of FIG. 3 shows the outer shapes of the first pipe coupler 16 and the second pipe coupler 17.

The first pipe coupler 16 is a cylindrical rotationally symmetric body having a hollow inside, and a hexagon nut is formed at one end thereof, and a female screw is cut so that the refrigerant pipe 25 can be connected. The other end of the first pipe coupler 16 is incorporated in the first pipe coupler main body 16a, and is sandwiched between the movable ring 16b that slides in the axial direction, and the first pipe coupler main body 16a and the movable ring 16b. A claw 16c having a spring action and a spring coil 16d provided between the first pipe coupler main body 16a and the movable ring 16b and suppressing the movement of the movable ring 16b are provided.
On the other hand, the second pipe coupler 17 is a cylindrical rotationally symmetric body having a hollow inside, and a hexagon nut is formed at one end of the second pipe coupler body 17a so that the second pipe coupler 17 can be connected to the refrigerant conduit 25. Screws are cut. And the other end part of the 2nd piping coupler main body 17a becomes a thin part which can be fitted with the inner side of the 1st piping coupler main body 16a, and the wall surface in the 1st piping coupler main body 16a is formed in the front-end | tip part. An O-ring 17b is provided so as to be in contact with the outer periphery. Further, a groove 17c is formed around the outer periphery of the narrowed portion of the second pipe coupler main body 17a between the hexagon nut formed in the second pipe coupler main body 17a and the O-ring 17b.

When the thinned portion of the second pipe coupler 17 is inserted into the cylinder of the first pipe coupler 16, the O-ring 17b of the second pipe coupler 17 is brought into close contact with the inner wall of the first pipe coupler 16 to suppress refrigerant leakage. To do. And the nail | claw 16c of the 1st piping coupler 16 and the groove | channel 17c of the 2nd piping coupler 17 mesh, and it prevents that the 1st piping coupler 16 and the 2nd piping coupler 17 remove | deviate.
Then, when the movable ring 16b is moved in the axial direction against the repulsive force of the spring coil 16d, the claw 16c is deformed by the spring action, and the engagement between the claw 16c and the groove 17c is loosened, whereby the first pipe coupler. 16 and the 2nd piping coupler 17 come off easily.
Thereby, while the connection of the some illuminating device 10 becomes easy, it becomes easy to cancel | release connection and to change the structure of the plant cultivation system 1. FIG.
As the 1st piping coupler 16 and the 2nd piping coupler 17, the thing by plastic materials, such as what uses metal materials, such as SUS and a copper alloy, and ABS resin can be used.

  In the present embodiment, the first pipe coupler 16 and the second pipe coupler 17 are used as connecting means, but the present invention is not limited to this. For example, a hose attachment port may be provided at an end portion where the refrigerant conduit 25 is extended, and the refrigerant conduit 25 (adjacent refrigerant conduit) of the adjacent lighting device 10 may be connected by a hose. Alternatively, the refrigerant conduit 25 and the adjacent refrigerant conduit may be abutted and fixed with a packing interposed therebetween.

FIG. 4 is a diagram illustrating an example of the inside of the illumination device 10. FIG. 4A shows the inside of the lighting device 10 with the transparent cover 12 removed from the lighting device 10 shown in FIG. FIG. 4B is a cross-sectional view taken along line IVB-IVB in FIG.
As shown in FIG. 4B, the lighting device 10 includes a light emitting element package 21 and a light emitting element package 21 on which semiconductor light emitting elements (first semiconductor light emitting element 64a and second semiconductor light emitting element 64b in FIG. 5 described later) are mounted. The circuit board 22 on which the circuit board 22 is mounted, the heat radiating board 24 to which the circuit board 22 is fixed, the circuit board 22 and the heat radiating board 24 are electrically insulated and the film-like insulating heat radiating material 23 having excellent thermal conductivity is provided. The light emitting device package 21 is provided to face the transparent cover 12 so that the generated light is emitted from the transparent cover 12.
Furthermore, the illuminating device 10 includes a reflector 26 that sets a light emitting direction so that light from the semiconductor light emitting element of the light emitting device package 21 is emitted from the transparent cover 12 of the illuminating device 10 in the vertical direction. .

As an example, as shown in FIG. 4A, the circuit board 22 has a plurality of light emitting element packages 21 arranged in three rows in the longitudinal direction. Then, three rows of reflectors 26 each having a reflecting surface 27 that is a paraboloid of revolution are provided so as to surround the light emitting device packages 21, corresponding to the rows of the light emitting device packages 21.
In FIG. 4, the light emitting device packages 21 are arranged in three rows on the circuit board 22, but the number is not limited to this. And although the circuit board 22 was comprised from one board | substrate, the board | substrate divided for every row | line | column may be sufficient. In addition, the circuit board 22 is a single board connected in the longitudinal direction of the lighting device 10, but may be a board divided into a plurality of parts in the longitudinal direction.
The circuit board 22 may be a glass epoxy board in which a copper cloth is provided on glass epoxy in which a glass cloth is impregnated with an epoxy resin, or a ceramic in which a thick film wiring such as Ag is provided. In terms of cost, glass epoxy is preferable.
The light emitting element package 21 may be mounted on the circuit board 22 by soldering, for example.

The illumination control wiring 31 is connected to the surface (semiconductor light emitting element mounting surface) of the circuit board 22 so that electric power for light emission is supplied to the semiconductor light emitting element. The illumination control wiring 31 is drawn out to the back surface of the heat dissipation board 24 through an opening provided in a part of the heat dissipation board 24. And the illumination control wiring 31 is connected by the back surface of the thermal radiation board | substrate 24, is taken out of the housing | casing as the illumination control wiring 31, and is connected to the illumination control part 30 provided outside the cultivation room 60.
The illumination control wiring 31 may be a vinyl-coated copper wire.

In FIG. 4, the reflectors 26 are provided for each row of the three rows of light emitting element packages 21 in the longitudinal direction of the lighting device 10. However, the reflector 26 may be provided for each light emitting element package 21. Moreover, the some reflector 26 divided | segmented into the longitudinal direction may be sufficient. In FIG. 4, the reflectors 26 are provided for each of the three rows of the light emitting element packages 21, but the three rows may be integrated without being divided. That is, the reflector 26 only needs to be able to emit light generated from the semiconductor light emitting element of the lighting device 10 in a direction perpendicular to the transparent cover 12 of the lighting device 10.
As the reflector 26, for example, an Al block provided with an opening whose cross section is a parabola can be used. The wall of the opening becomes the reflection surface 27. Moreover, what formed metal films, such as Al and Ag, in the resin etc. which provided the opening from which the wall becomes the reflective surface 27 by vapor deposition etc. can be used.
In addition, that the light is emitted in the vertical direction with respect to the transparent cover 12 by the reflector 26 means that the amount of light in the vertical direction is larger than in the case where the reflector 26 is not provided.

The heat dissipation substrate 24 is a substrate for discharging heat generated with light emission of the semiconductor light emitting element to the outside of the cultivation room 60, and is made of a material having good thermal conductivity, and includes a refrigerant conduit 25. .
The refrigerant conduit 25 is configured in close contact with the conduit insertion portion of the heat dissipation substrate 24. Since the heat transfer efficiency is poor simply by insertion, the tube diameter is expanded by compressed air with compressed air, and the tube is formed through a conduit drawing process in which the conduit is closely attached to the conduit insertion portion of the heat dissipation substrate 24. Therefore, the heat from the semiconductor light emitting element mounted on the wiring board 22 is transmitted to the refrigerant conduit 25 through the heat radiating board 24 and discharged outside the cultivation room 60 by the refrigerant. In other words, the refrigerant flowing through the refrigerant conduit 25 cools the heat dissipation substrate 24 and cools the light emitting element package 21 mounted on the circuit board 22 disposed in close contact with the heat dissipation substrate 24. Therefore, since the heat from the semiconductor light emitting element is not discharged into the cultivation room 60, the temperature and humidity in the cultivation room 60 can be controlled independently of the heat generated from the semiconductor light emitting element.

Therefore, the number of light emitting element packages 21 that can be mounted on the circuit board 22 is determined by the cooling capacity determined by the temperature, flow rate, etc. of the refrigerant and the heat generation amount of the semiconductor light emitting elements. In particular, the length of the refrigerant conduit 25 in the direction perpendicular to the direction in which the refrigerant flows (the width of the circuit board 22) is limited by heat dissipation characteristics such as the thermal resistance of the heat dissipation board 24.
As the heat dissipation substrate 24, Al or Cu having excellent thermal conductivity can be used. In particular, the refrigerant conduit 25 is preferably made of Cu which is not easily corroded.
In order to improve heat dissipation, a through-hole penetrating to the back surface of the circuit board 22 is opened in the bonding pad of the circuit board 22 to which the lead on which the chip of the light emitting device package 21 is mounted is soldered. It is desirable to connect via copper foil and plated metal. Of course, the back surface of the circuit board 22 should also be patterned so that the semiconductor light emitting device is not short-circuited.
In addition, the refrigerant | coolant conduit | pipe 25 is arrange | positioned, without contacting the exterior cover 11 grade | etc., As shown in FIG.4 (b). The lighting device 10 is filled with dry air, dry nitrogen, etc. as described above. Therefore, even if a refrigerant having a temperature lower than the temperature of the cultivation room 60 is supplied to the refrigerant conduit 25, the circuit board 22, the light emitting element package 21, and other components including the refrigerant conduit 25 and the heat dissipation substrate 24 to which the refrigerant conduit 25 is attached are condensed. Is suppressed. Thereby, the corrosion by the moisture and dew condensation of the circuit board 22, the light emitting element package 21, and other components including the refrigerant conduit 25 and the heat dissipation board 24 can be suppressed.

The insulating heat dissipating material 23 is disposed in close contact with each other between the circuit board 22 and the heat radiating board 24 so as to maintain electrical insulation and conduct heat generated from the circuit board 22 to the heat radiating board 24. Is provided. As described above, the refrigerant conduit 25 provided in close contact with the heat dissipation substrate 24 is connected to the first pipe coupler 16 and the second pipe coupler 17. The first piping coupler 16 and the second piping coupler 17 are provided outside the lighting device 10. For this reason, an operator engaged in plant cultivation may touch the first piping coupler 16 or the second piping coupler 17. Therefore, in order to prevent electric shock, no current should flow through the first pipe coupler 16 and the second pipe coupler 17. Therefore, it is necessary to electrically insulate the heat dissipation board 24 and the circuit board 22 from each other.
The insulating heat dissipation material 23 electrically insulates the circuit board 22 and the heat dissipation board 24 and conducts heat generated from the semiconductor light emitting element on the circuit board 22 to the heat dissipation board 24. For this reason, the insulating heat dissipating material 23 is preferably a film having flexibility, high electrical insulation resistance, and low thermal resistance so that the circuit board 22 and the heat radiating board 24 can be in close contact with each other. As such a film, polyethylene terephthalate (PET), polyethylene (PE), or the like can be used.

The circuit board 22 and the heat radiating board 24 may be fixed with screws or the like in a portion where the wiring of the circuit board 22 is not provided.
The reflector 26 may also be fixed to the heat dissipation board 24 via the circuit board 22 with screws or the like. Also in this case, attention should be paid to the insulation distance between the pattern of the circuit board 22 and the mounting screw so as not to leak electricity to the mounting screw.
And what is necessary is just to fix the thermal radiation board | substrate 24 by inserting in the slit provided in the exterior cover 11, as shown in FIG.4 (b).

  Now, the refrigerant | coolant conduit | pipe 25 shown in FIG.4 (b) is connected to the 1st piping coupler 16 and the 2nd piping coupler 17. FIG. At this time, when piping is required between the heat radiation board 25 and the first piping coupler 16 and the second piping coupler 17, for example, a screw such as Cu may be provided and added. What is necessary is just to comprise so that a refrigerant | coolant may circulate through the some illuminating device 10, without a refrigerant | coolant leaking.

  As an example, the illumination device 10 has a length of 1200 mm, a width of 100 mm, and a depth of 45 mm. The diameter of the refrigerant conduit 25 is 12 mm. In addition, it is not limited to this shape, It is good also as another value.

  FIG. 5 is a diagram illustrating an example of the configuration of the light emitting element package 21 used in the present embodiment. Here, FIG. 5A shows a top view of the light emitting element package 21, and FIG. 5B shows a VB-VB sectional view of FIG. 5A.

The light emitting device package 21 includes a resin container 61 in which a recess 61a is formed in an opening surface 71 formed in a planar shape, anode lead parts 62a and 62b made of a lead frame integrated with the resin container 61, and a cathode lead part. 63a, 63b, and a first semiconductor light emitting element 64a and a second semiconductor light emitting element 64b as an example of the light emitting element attached to the bottom surface 70 of the recess 61a. That is, the light emitting element package 21 is a 2-in-1 package in which the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b are mounted together. As an example, the first semiconductor light emitting element 64a is a blue light emitting element having an emission peak wavelength of 450 nm. On the other hand, the second semiconductor light emitting element 64b is a red light emitting element having an emission peak wavelength of 660 nm.
As the first semiconductor light emitting element 64a, one having an emission peak wavelength of 400 to 500 nm can be used. Moreover, as the second semiconductor light emitting element 64b, one having an emission peak wavelength of 655 to 675 nm can be used. Here, the emission peak wavelength means a wavelength having the highest light intensity.

  In the resin container 61, a thermoplastic resin (referred to as a white resin in the following description) containing a white pigment is injection-molded in a metal lead portion including the anode lead portions 62a and 62b and the cathode lead portions 63a and 63b. It is formed by.

  In addition, a material with sufficient heat resistance is selected for the white resin so that it can cope with a process requiring high temperature such as solder reflow. PPA (polyphthalamide) is most commonly used as the base resin, but may be a liquid crystal polymer, an epoxy resin, polystyrene, or the like. Among these, in this embodiment, nylon 4T, nylon 6T, nylon 6I, nylon 9T, and nylon M5T, which are copolymers of diamine and isophthalic acid or terephthalic acid, can be particularly preferably used as PPA.

  The recess 61 a provided in the resin container 61 includes a bottom surface 70 having a circular shape, an opening portion 71 having a circular shape, and a wall surface 80 that rises from the periphery of the bottom surface 70 toward the opening portion 71. ing. Here, the bottom surface 70 is a gap between the anode lead portions 62a and 62b and the cathode lead portions 63a and 63b exposed to the recess 61a, and the anode lead portions 62a and 62b and the cathode lead portions 63a and 63b. It is comprised with the white resin of the resin container 61. FIG. On the other hand, the wall surface 80 is made of a white resin constituting the resin container 61. The shape of the bottom surface 70 may be any of a circle, a rectangle, an ellipse, and a polygon. The shape of the opening 71 may be any of a circle, a rectangle, an ellipse, and a polygon, and may be the same as the bottom shape.

  A part of each of the anode lead parts 62a and 62b and the cathode lead parts 63a and 63b is held between the resin containers 61, and the other part is exposed to the outside of the resin container 61. These are terminals for applying a current to the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b. When surface mounting is assumed, as shown in FIG. 5, the anode lead portions 62a and 62b and the cathode lead portions 63a and 63b are respectively bent to the back side of the resin container 61, and the tip is placed on the bottom of the resin container 61. May be arranged.

  The anode lead parts 62a and 62b and the cathode lead parts 63a and 63b, that is, the lead frame is a metal plate having a thickness of about 0.1 to 0.5 mm, and is based on a metal conductor such as a copper alloy, A silver plating layer is formed on the surface by silver plating.

The first semiconductor light emitting element 64a is bonded and fixed to the cathode lead portion 63a disposed on the bottom surface 70 of the recess 61a with a die bond agent made of silicone resin or epoxy resin. Similarly, the second semiconductor light emitting element 64b is bonded and fixed to the anode lead portion 62b disposed on the bottom surface 70 of the recess 61a with a die bond agent made of silicone resin or epoxy resin.
In addition, an AuSn layer is formed on the back surface of the first semiconductor light emitting element 64a via a metal layer such as Al or Ni, and fixed on the cathode lead portion 63a disposed on the bottom surface 70 of the recess 61a by heat melting. More preferably. The same applies to the second semiconductor light emitting element 64b.
The first semiconductor light emitting element 64a has an n-type pad electrode and a p-type pad electrode. The p-type pad electrode is connected to the anode lead portion 62a and the n-type pad electrode is connected to the cathode lead via the bonding wire 65. Each is connected to the part 63a. Similarly, the second semiconductor light emitting element 64b also has an n-type pad electrode and a p-type pad electrode, where the p-type pad electrode is in the anode lead portion 62b, the n-type pad electrode is in the cathode lead portion 63b, They are connected via bonding wires 65.

The light emitting device package 21 is sealed with a sealing resin so as to fill the recess 61a. The sealing resin only needs to be made of a transparent resin that transmits light emitted from the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b.
For example, as the transparent resin, a curable resin for sealing so as to cover the concave portion, a curing agent for curing the transparent resin, and further blended as necessary, for example, an antioxidant, a discoloration preventing agent, a photodegradation preventing agent, a reaction That contain a reactive diluent, an inorganic filler, a flame retardant, an organic solvent, and the like.
Specific examples of the curable resin include silicone resin, epoxy resin, epoxy silicone hybrid resin, acrylic resin, and polyimide resin. Among these, from the viewpoint of heat resistance, a silicone resin and an epoxy resin are preferable, and a silicone resin is particularly preferable.
Here, the anode lead portions (62a, 62b) and the cathode lead portions (63a, 63b) are provided in the first semiconductor light emitting device 64a and the second semiconductor light emitting device 64b, respectively. May be.
Here, the light emitting device package 21 is a 2-in-1 package in which the two first semiconductor light-emitting devices 64a and the second semiconductor light-emitting device 64b are mounted together. However, a multi-chip is also used in a 1-in-1 package in which a single chip is mounted. An on-board package may be used. The wiring in the package in the case of a multichip may be a parallel circuit having a common terminal at one end or both ends, and may have an independent positive electrode and negative electrode for each chip. Further, a series circuit in which chips are connected in series in a package may be used.

Next, an example of the first semiconductor light emitting element 64a (blue light emitting element) and the second semiconductor light emitting element 64b (red light emitting element) will be described. Note that the structures and numerical values shown below are representative structures and numerical values, and are not limited to the structures and numerical values shown here.
<Blue light emitting element>
FIG. 6 is a cross-sectional view for explaining an example of the configuration of the first semiconductor light emitting element 64a that emits blue light used in the present embodiment. FIG. 7 is a top view of the blue light emitting semiconductor light emitting element 64a. Here, a blue light emitting semiconductor light emitting element 64a having an emission peak wavelength of 450 nm will be described.
As shown in FIG. 6, the first semiconductor light emitting device 64 a includes a first substrate 110, an intermediate layer 120 stacked on the first substrate 110, and a foundation layer 130 stacked on the intermediate layer 120. In addition, the first semiconductor light emitting element 64 a includes a first n-type semiconductor layer 140 stacked on the base layer 130, a first light-emitting layer 150 stacked on the first n-type semiconductor layer 140, and the first light-emitting layer 150. The first p-type semiconductor layer 160 is stacked. In the following description, the first n-type semiconductor layer 140, the first light emitting layer 150, and the first p-type semiconductor layer 160 are collectively referred to as a first stacked semiconductor layer 100 as necessary. Further, the first semiconductor light emitting element 64 a includes a transparent electrode 170 that is stacked on the first p-type semiconductor layer 160 and transmits light generated by the first light emitting layer 150. The first semiconductor light emitting element 64a includes a first bonding pad electrode 210 that is stacked on the upper surface 170c of the transparent electrode 170 and serves as a p-type pad electrode. Furthermore, the first semiconductor light emitting device 64a is exposed to the semiconductor layer of the first n-type semiconductor layer 140 exposed by cutting out part of the first p-type semiconductor layer 160, the first light-emitting layer 150, and the first n-type semiconductor layer 140. A second bonding pad electrode 240 that is stacked on a part of the surface 140c and serves as an n-type pad electrode is provided.
Further, the first semiconductor light emitting element 64a is configured such that the first n-type semiconductor layer 140, the first light-emitting layer 150, and the first p-type semiconductor layer except for a part of the surface of the first bonding pad electrode 210 and the second bonding pad electrode 240. 160 and a first protective layer 180 that covers the transparent electrode 170.

The first semiconductor light emitting element 64a is bonded and fixed onto the cathode lead portion 63a as described above, and the first bonding pad electrode 210 is connected to the anode lead portion 62a of the lead frame by the bonding wire 65. The second bonding pad electrode 240 is connected to the cathode lead portion 63a of the lead frame by the bonding wire 65.
The first bonding pad electrode 210 is a positive electrode, the second bonding pad electrode 240 is a negative electrode, and the first stacked semiconductor layer 100 (specifically, the first p-type semiconductor layer 160, the first light emitting layer 150, and the first n-type semiconductor layer 140). ) Causes the first light emitting layer 150 to emit light. The generated light is extracted to the outside of the semiconductor light emitting element 64a from the upper surface of the transparent electrode 170 where the first bonding pad electrode 210 is not provided.

  In addition, about the structure of the 1st semiconductor light-emitting device 64a, its manufacturing method, etc., it can carry out with reference to Unexamined-Japanese-Patent No. 2009-123718, for example.

In the present embodiment, as shown in FIG. 6, the first protective layer 180 made of silicon oxide such as SiO ₂ is used as the transparent electrode 170, the first p-type semiconductor layer 160, and the first n-type semiconductor layer 140. The semiconductor layer exposed surface 140c may be formed so as to cover the upper surface (including etched side walls), the peripheral portion of the first bonding pad electrode 210, the peripheral portion of the second bonding pad electrode 240, and the like.
This shields the first semiconductor light emitting element 64a except for the upper surface of the bonding pad electrodes (210, 240), and greatly reduces the possibility of external air and moisture entering the first semiconductor light emitting element 64a. Thus, the transparent electrode 170 and the bonding pad electrodes (210, 240) of the first semiconductor light emitting element 64a can be prevented from being peeled off.
The thickness of the first protective layer 180 is preferably 50 to 1000 nm, more preferably 100 to 500 nm, and still more preferably 150 to 450 nm.
By setting the thickness of the first protective layer 180 to 50 to 1000 nm, it is possible to greatly reduce the possibility that external air or moisture may penetrate into the first light emitting layer 105 of the first semiconductor light emitting element 64a. The first bonding pad electrode 210 and the second bonding pad electrode 240 of the light emitting element 64a can be prevented from peeling off.

The first protective layer 180 is formed by, for example, firstly transparent electrode 170, first p-type semiconductor layer 160, upper surface of semiconductor layer exposed surface 140c of first n-type semiconductor layer 140 (including etched sidewalls), first After forming the first protective layer 180 made of SiO _{2 on} the surface of the first bonding pad electrode 210 and the surface of the second bonding pad electrode 240, a resist (not shown) is applied on the first protective layer 180.
Then, a part of the resist on the surfaces of the first bonding pad electrode 210 and the second bonding pad electrode 240 is removed, and the first protective layer 180 is removed by a known etching technique, whereby a part of the surface of each electrode is obtained. To expose.
As described above, the first semiconductor light emitting device 64a is manufactured.

<Red light emitting element>
FIG. 8 is a cross-sectional view illustrating an example of the configuration of the second semiconductor light emitting element 64b that emits red light used in the present embodiment. FIG. 9 is a top view of the second semiconductor light emitting element 64b that emits red light. Here, the second semiconductor light emitting element 64b that emits red light having an emission peak wavelength of 660 nm will be described. 8 is a cross-sectional view taken along line VIII-VIII in the top view of FIG.

As shown in FIG. 8, the second semiconductor light emitting element 64 b is configured by bonding a second stacked semiconductor layer 300 and a second substrate 310. The second stacked semiconductor layer 300 includes a strain adjustment layer 320, a second p-type semiconductor layer 330 that functions as a lower cladding layer, a second light emitting layer 340, and a second n-type semiconductor layer 350 that functions as an upper cladding layer. It is configured.
The second semiconductor light emitting device 64b is formed on the upper surface 350c of the second n-type semiconductor layer 350, and functions as an n-type pad electrode. The second n-type semiconductor layer 350 of the second stacked semiconductor layer 300 is formed. A fourth bonding pad electrode 410 is formed on the upper surface 320c of the strain adjustment layer 320 exposed by cutting out a part of the second light emitting layer 340 and the second p-type semiconductor layer 330, and serves as a p-type pad electrode.
As shown in FIG. 9, the third bonding pad electrode 400 is connected to the wiring 401 formed on the second n-type semiconductor layer 350, for example, in a lattice shape. The wiring 401 is formed of a thin line with the same material as the third bonding pad electrode 400 so as not to affect the extraction of light from the second n-type semiconductor layer 350. Accordingly, the potential distribution of the second n-type semiconductor layer 350 is made more uniform than that in the case where the wiring 401 is not provided, and the light emission distribution of the second light emitting layer 340 is made uniform.

  Further, the second semiconductor light emitting element 64b has a strain adjustment layer 320, a second p-type semiconductor layer 330, a second light emitting layer 340, except for a part of the surface of the third bonding pad electrode 400 and the fourth bonding pad electrode 410. A second protective layer 360 is provided to cover the second n-type semiconductor layer 350.

  In the second semiconductor light emitting device 64b, the third bonding pad electrode 400 is a negative electrode, the fourth bonding pad electrode 410 is a positive electrode, and the second stacked semiconductor layer 300 (more specifically, the second p-type semiconductor layer is interposed therebetween). 330, the second light emitting layer 340, and the second n-type semiconductor layer 350), the second light emitting layer 340 emits light by passing a current. The generated light is extracted to the outside of the second semiconductor light emitting element 64b from the upper surface of the second n-type semiconductor layer 350 where the third bonding pad electrode 400 and the wiring 410 are not provided or from the side surface of the second substrate 310. .

Hereinafter, the configuration of the second semiconductor light emitting element 64b will be described in more detail.
(Second board)
As shown in FIG. 8, the second substrate 310 is bonded to the strain adjustment layer 320 that constitutes the second stacked semiconductor layer 300. The second substrate 310 has sufficient strength to mechanically support the second light emitting layer 340 and has a wide band gap energy so that light emitted from the second light emitting layer 340 can be transmitted. The two light emitting layers 340 are made of a material that is optically transparent with respect to the emission wavelength. For example, III-V group compound semiconductor crystals such as gallium phosphide (GaP), aluminum gallium arsenide (AlGaAs), and gallium nitride (GaN), and II-VI such as zinc sulfide (ZnS) and zinc selenide (ZnSe). It can be composed of a group IV compound semiconductor crystal, a group IV semiconductor crystal such as hexagonal or cubic silicon carbide (SiC), an insulating substrate such as glass and sapphire.
On the other hand, a functional substrate having a highly reflective surface on the bonding surface can also be selected. For example, a metal substrate or alloy substrate made of silver, gold, copper, aluminum or the like on the surface, or a composite substrate in which a metal mirror structure is formed on a semiconductor can be selected.

  The second substrate 310 preferably has a thickness of, for example, 50 μm or more in order to support the second light emitting layer 340 with sufficient mechanical strength. Further, in order to facilitate mechanical processing of the second substrate 310 after joining with the second stacked semiconductor layer 300, it is preferable that the thickness does not exceed 300 μm. That is, the second substrate 310 is optimally composed of an n-type GaP substrate having a thickness of 50 μm or more and 300 μm or less.

  Further, as shown in FIG. 8, the side surface of the second substrate 310 is a vertical surface that is substantially perpendicular to the upper surface of the second n-type semiconductor layer 350 that is a light extraction surface on the side close to the second stacked semiconductor layer 300. The inclined surface 310b which inclines inside the 2nd board | substrate 310 is comprised in the side far from the 2nd laminated semiconductor layer 300 which comprises 310a. Thereby, the light emitted from the second light emitting layer 340 to the second substrate 310 side can be efficiently extracted to the outside. That is, of the light emitted from the second light emitting layer 340 to the second substrate 310 side, the light reflected by the vertical surface 310a can be extracted from the inclined surface 310b. On the other hand, the light reflected by the inclined surface 310b can be extracted from the vertical surface 310a. Thus, the light extraction efficiency can be increased by the synergistic effect of the vertical surface 310a and the inclined surface 310b.

In the present embodiment, it is preferable that the angle α formed between the inclined surface 310b and the surface parallel to the upper surface of the second n-type semiconductor layer 350, which is the light extraction surface, is in the range of 55 to 80 degrees. . By setting it as such a range, the light reflected by the bottom face 310c of the 2nd board | substrate 310 can be efficiently taken out outside.
The thickness of the portion of the vertical surface 310a of the second substrate 310 is preferably 30 to 100 μm. By setting the thickness of the vertical surface 310a within this range, the light reflected by the bottom surface 310c of the second substrate 310 can be efficiently returned to the light emitting surface at the vertical surface 310a, and the second n-type which is a light extraction surface. It is possible to emit from the upper surface of the semiconductor layer 350 (the portion where the third bonding pad electrode 400 is not formed). Thereby, the light emission efficiency of the second semiconductor light emitting element 64b can be increased.

  The inclined surface 310b of the second substrate 310 is preferably roughened. When the inclined surface 310b is roughened, an effect of suppressing total reflection on the inclined surface 310b and increasing the light extraction efficiency from the inclined surface 310b can be obtained.

(Strain adjustment layer)
In the present embodiment, a strain adjustment layer 320 is provided between the second substrate 310 and the second p-type semiconductor layer 330. Since the strain adjustment layer 320 is transparent with respect to the emission wavelength from the second light emitting layer 340, the second semiconductor light emitting element 64b having high output and high efficiency can be obtained without absorbing light emission.
The strain adjusting layer 320 has a lattice constant smaller than that of a GaAs substrate (not shown) used when forming the second stacked semiconductor layer 300. For this reason, generation | occurrence | production of the curvature of the 2nd laminated semiconductor layer 300 can be suppressed. Thereby, since the variation in the amount of strain of the strained light emitting layer provided in the second light emitting layer 340 is reduced in the second light emitting layer 340, the second semiconductor light emitting element 64b having excellent monochromaticity can be obtained. .
The strain adjusting layer 320 is, for example, p-type GaP having an Mg-doped carrier concentration of about 3 × 10 ¹⁸ / cm ³ and a thickness of about 9 μm.

(Second p-type semiconductor layer)
The second p-type semiconductor layer 330 serving as the lower cladding layer is provided between the strain adjustment layer 320 and the second light emitting layer 340. The second p-type semiconductor layer 330 is, for example, Mg-doped (Al _0.7 Ga _0.3 ) _0.5 In _0.5 P, and has a carrier concentration of about 8 × 10 ¹⁷ / cm ³ and a thickness of about 0. .5 μm.
Further, between the strain adjustment layer 320 and the second p-type semiconductor layer 330, for example, (Al _0.5 Ga _0.5 ) _0.5 In _0.5 P, and the carrier concentration is about 8 × 10 ¹⁷ / cm ^3. An intermediate layer having a thickness of about 0.05 μm may be provided.

(Second light emitting layer)
A second light-emitting layer 340 that emits light is provided between the second p-type semiconductor layer 330 and the second n-type semiconductor layer 350. The second light emitting layer 340 preferably has a peak emission wavelength in the emission spectrum of 655 to 675 nm, and more preferably 660 to 670 nm. The emission wavelength in the above range is one of emission wavelengths suitable for light sources for plant growth (photosynthesis), and has high reaction efficiency for photosynthesis.
On the other hand, a long wavelength of 700 nm or more causes a reaction to suppress plant growth. For this reason, it is desirable that the amount of light in the long wavelength region is small. Therefore, in order to grow plants efficiently, a red light source that has strong light in the wavelength region of 655 to 675 nm optimum for the photosynthesis reaction and does not contain light having a long wavelength of 700 nm or more is most preferable. Therefore, in order to obtain a preferable red light source, the half width needs to be narrow.
From these facts, the half width of the emission spectrum is preferably 10 to 40 nm, and the emission intensity at the emission wavelength of 700 nm is preferably less than 10% of the emission intensity at the peak emission wavelength.

The second light emitting layer 340 is configured by alternately stacking strained light emitting layers and barrier layers. The strained light-emitting layer is, for example, undoped Ga _0.44 In _0.56 P with a thickness of about 17 nm, and the barrier layer is, for example, undoped with a thickness of about 19 nm (Al _0.53 Ga _0.47 ) _0.5. In _0.5 P. Then, for example, 22 pairs of strained light emitting layers and barrier layers are alternately laminated.

(Second n-type semiconductor layer)
A second n-type semiconductor layer 350 serving as an upper cladding layer is provided on the upper surface of the second light emitting layer 340.
The second n-type semiconductor layer 350 has, for example, a Si-doped carrier concentration of about 1 × 10 ¹⁸ / cm ³ and a thickness of about 0.5 μm (Al _0.7 Ga _0.3 ) _0.5 In _{0. 5} P.
In addition, on the upper surface of the second n-type semiconductor layer 350, for example, a carrier concentration doped with Si is about 2 × 10 ¹⁸ / cm ³ and the thickness is about 3.5 μm (Al _0.7 Ga _0.3 ) _{0. An} n-type contact layer made of ₅ In _0.5 P may be provided.

(Third bonding pad electrode and fourth bonding pad electrode)
The third bonding pad electrode 400, which is an n-type pad electrode, is provided on the upper surface 350c of the second n-type semiconductor layer 350. For example, an alloy made of AuGe, Ni alloy / Au can be used.
On the other hand, the fourth bonding pad electrode 410, which is a p-type pad electrode, is provided on the exposed upper surface 320c of the strain adjustment layer 320. For example, an alloy made of AuBe / Au can be used.

The second semiconductor light emitting element 64b described above can be manufactured as follows.
First, the second stacked semiconductor layer 300 is sequentially stacked on a GaAs substrate made of an n-type GaAs single crystal doped with Si. The GaAs substrate has, for example, a plane inclined by 15 ° from the (100) plane in the (0-1-1) direction, and has a carrier concentration of 2 × 10 ¹⁸ / cm ³ .
On the GaAs substrate, the second stacked semiconductor layer 300 is formed in the order of the second n-type semiconductor layer 350, the second light emitting layer 340, the second p-type semiconductor layer 330, and the strain adjustment layer 320.
Note that an n-type buffer layer made of GaAs having a carrier concentration doped with, for example, Si of about 2 × 10 ¹⁸ / cm ³ and a thickness of about 0.5 μm between the GaAs substrate and the second stacked semiconductor layer 300. May be provided.

In this embodiment, the second stacked semiconductor layer 300 is epitaxially grown on a GaAs substrate having a diameter of 76 mm and a thickness of 350 μm by using a low pressure metal organic chemical vapor deposition (MOCVD) method. When the epitaxial growth is performed, trimethylaluminum ((CH ₃ ) ₃ Al), trimethyl gallium ((CH ₃ ) ₃ Ga), and trimethylindium ((CH ₃ ) ₃ In) can be used as a group III constituent material. Further, biscyclopentadienyl magnesium (bis- (C ₅ H ₅ ) ₂ Mg) can be used as a Mg doping material. Furthermore, disilane (Si ₂ H ₆ ) can be used as a Si doping material. Then, as the raw material of Group V constituent element, phosphine _(PH 3), arsine (AsH ₃₎ may be used. As the growth temperature of each layer, the strain adjusting layer 320 made of p-type GaP is grown at 750 ° C., and the other layers are grown at 700 ° C.

Next, the strain adjustment layer 320 is polished from the surface to a depth of about 1 μm and mirror-finished. On the other hand, a second substrate 310 made of n-type GaP to be attached to the mirror-polished surface of the strain adjustment layer 320 is prepared. For example, the second substrate 310 has a diameter of 76 mm and a thickness of 250 μm. The second substrate 310 is a (111) -plane single crystal substrate doped with Si so that the carrier concentration is about 2 × 10 ¹⁷ / cm ³ . The surface of the second substrate 310 is polished to a mirror surface before being bonded to the strain adjustment layer 320.

Subsequently, the second substrate 310 and the GaAs substrate on which the second laminated semiconductor layer 300 is formed are carried into a general semiconductor material pasting apparatus, and the inside of the semiconductor material pasting apparatus is set to 3 × 10 ⁻⁵ Pa, for example. Exhaust to vacuum.

Thereafter, the surfaces of the second substrate 310 and the strain adjusting layer 320 of the second stacked semiconductor layer 300 are irradiated with, for example, an neutralized (Neutral) Ar beam for 3 minutes by colliding electrons, and both surfaces are irradiated. The gas adsorbed on was removed.
Thereafter, in the semiconductor material pasting apparatus that maintains the vacuum, the surfaces of the second substrate 310 and the strain adjustment layer 320 of the second laminated semiconductor layer 300 are overlapped, and a load is applied so that, for example, the pressure is 50 g / cm ^2. Bond at room temperature.

  Further, the GaAs substrate and the GaAs buffer layer are selectively removed with an ammonia-based etchant. Next, a third bonding pad electrode 400 was formed on the surface of the contact layer by vacuum deposition so that the thickness of AuGe and Ni alloy was 0.5 μm, Pt was 0.2 μm, and Au was 1 μm. Thereafter, patterning was performed using known photolithography to form a third bonding pad electrode 400 serving as an n-type pad electrode.

Next, the second n-type semiconductor layer 350, the second light emitting layer 340, and the second p-type semiconductor layer 330 in the region where the fourth bonding pad electrode 410 is to be formed were selectively removed to expose the strain adjustment layer 320. A fourth bonding pad electrode 410 serving as a p-type pad electrode is formed on the exposed upper surface 320c of the strain adjustment layer 320 by vacuum deposition so that AuBe is 0.2 μm and Au is 1 μm.
Thereafter, heat treatment is performed at 450 ° C. for 10 minutes to form an alloy, thereby forming a third bonding pad electrode 400 and a fourth bonding pad electrode 410 that respectively function as low-resistance n-type and p-type pad electrodes.

The second semiconductor light emitting device 64b manufactured as described above is incorporated into the light emitting device package 21 as shown in FIG. That is, the bottom surface 310c of the second semiconductor light emitting element 64b is installed on the anode lead part 62b of the lead frame, and the third bonding pad electrode 400 is connected to the cathode lead part 63b by, for example, a gold bonding wire 65, The fourth bonding pad electrode 410 is connected to the anode lead portion 62 a by a gold bonding wire 65. Thus, the n-type GaP second substrate 310 and the third bonding pad electrode 400 have the same potential.
The recess 61a of the light emitting element package 21 may be sealed with a general epoxy resin after wire bonding.

Note that the second semiconductor light emitting element 64b emitting red light in the present embodiment uses a quaternary compound semiconductor made of AlGaInP. In the present specification, the description of AlGaInP, AlInP, or the like may be simplified by describing the composition ratio of each element. On the other hand, as a semiconductor light emitting device that emits light of 660 nm, a device using an AlGaAs ternary compound semiconductor is known.
The second semiconductor light emitting element 64b using AlGaInP in the present embodiment has a characteristic that it is strong against corrosion due to moisture because the ratio of Al is lower than that using AlGaAs.

  The first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b described above are examples, and it is obvious that semiconductor light emitting elements having other structures and semiconductor light emitting elements having other emission peak wavelengths can be used. .

As described above, in the present embodiment, the light emitting element package 21 in which the blue light emitting first semiconductor light emitting element 64a and the red light emitting second semiconductor light emitting element 64b necessary for plant growth are mounted is used. Therefore, manufacture of the illuminating device 10 is easy.
The lead frame anode lead portions 62a and 62b and the cathode lead portions 63a and 63b are individually provided so that each of the first semiconductor light emitting device 64a and the second semiconductor light emitting device 64b can be turned on / off. . Therefore, by providing the illumination control wiring 31 separately for the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b, the density of photons (photon density) of red and blue can be controlled independently depending on the type of plant. can do.
In the lighting device 10 manufactured as described above, the photon density immediately below 20 cm is 300 μmol / m ² / sec when a 20 mA current is applied to each of the first semiconductor light emitting elements 64a that emit blue light, and the second semiconductor that emits red light. When 20 mA was applied per light emitting element 64b, the current was 200 μmol / m ² / sec.
Further, the semiconductor light emitting device is not turned on, (I) left at 5 ° C. for 15 minutes, (II) raised to 60 ° C. in 15 minutes, (III) left at 60 ° C. for 15 minutes, (IV) in 15 minutes In a temperature cycle test in which the temperature cycle of decreasing the temperature to 5 ° C. and returning to (I) was repeated 1000 times, the inner surface of the transparent cover 12 (glass) of the lighting device 10 was cloudy and no condensation was observed. Further, in an environment of 30 ° C. and 95% RH (relative humidity), continuous lighting for 1000 hours was performed by flowing 10 mA to the first semiconductor light emitting element 64 a that emits blue light and 30 mA to the second semiconductor light emitting element 64 b that emits red light. In the test, no rust or non-lighting of the semiconductor light emitting element was observed in the lighting device 10, and the photon density was maintained at 98% of the initial value.

(Second Embodiment)
In the first embodiment, the light emitting element package 21 including the first semiconductor light emitting element 64a that emits blue light and the second semiconductor light emitting element 64b that emits red light is mounted on the circuit board 22, and the circuit board 22 is further attached to the heat dissipation board 24. It was mounted on. In this method, the heat generated from the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b is radiated from the back surface of the circuit board 22 through the metal leads of the light emitting element package 21 and the through holes of the circuit board 22. 24.
Among these, the metal lead of the light emitting element package 21 is as thin as 0.15 mm, and the thermal resistance of the light emitting element package 21 is not so low as 100 ° C./W.
In the present embodiment, in order to further improve the cooling efficiency, the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b are directly bonded to the metal base portion of the metal base circuit board 32 (COB type: Chip on Board). Formula).

FIG. 10 is a cross-sectional view of an example of the lighting device 20 to which the exemplary embodiment is applied. In addition, the illuminating device 20 is equipped with the exterior cover 11, the transparent cover 12, the 1st side cover 13, and the 2nd side cover 14 which comprise a housing | casing similarly to 1st Embodiment. Further, also in the present embodiment, the first semiconductor light emitting element 64a emitting blue light and the second semiconductor light emitting element 64b emitting red light are used.
In the present embodiment, a refrigerant pipe 25 is provided on one surface of the heat dissipation substrate 24 as in the first embodiment. A COB circuit board 32 is screwed to the other surface of the heat dissipation board 24 via an insulating heat dissipation material 23. In FIG. 10, the reflector 26 is provided, but it is not necessary to provide it.

FIG. 11 illustrates an example of a connection relationship between the connection wiring 520 provided on the chip-on-board (COB) circuit board 32 and the semiconductor light emitting elements (the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b). FIG. Here, FIG. 11A is a plan view for explaining an example of a circuit pattern on the COB circuit board 32 screwed to the heat dissipation board 24 via the insulating heat dissipation material 23. FIG. 11B is an enlarged view of a portion surrounded by a broken line in FIG. 11A, and the first semiconductor light emitting element 64 a and the second semiconductor light emitting element 64 b arranged on the circuit board 32, and connection wiring The connection relationship with 520 is shown.
In the description of the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

First, referring to FIG. 11A, the circuit board 32 on which the connection wiring 520 is formed will be described.
The circuit board 32 is a board for discharging heat generated by the light emission of the first semiconductor light emitting element 64 a and the second semiconductor light emitting element 64 b to the outside of the cultivation room 60. Therefore, the circuit board 32 is made of a material having good thermal conductivity.
As the circuit board 32, Al or Cu having excellent thermal conductivity can be used.

On the other hand, an insulating layer 510 having connection wirings 520 formed on both sides is provided on the surface of the circuit board 32. Then, the insulating layer 510 is removed so that the surface of the circuit board 32 is exposed so that the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b can be directly mounted on the circuit board 32, and a plurality of semiconductor light emitting elements are installed. A part 530 is provided. In FIG. 11A, as an example, a plurality of semiconductor light emitting element installation portions 530 are arranged in two rows at equal intervals in the longitudinal direction of the circuit board 32 per row.
In each of the plurality of semiconductor light emitting element installation portions 530, for example, the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b are arranged in pairs. The first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b are supplied with power through the connection wiring 520. As shown in FIG. 11A, the connection wiring 520 is specifically composed of wiring divided into a plurality of parts.

Next, in FIG. 11B, an example of a connection relationship between the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b and the connection wiring 520 will be described.
The first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b constitute a pair, and the pair is disposed in the semiconductor light emitting element installation portion 530. The first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b are arranged side by side in the lateral direction of the circuit board 32, the first semiconductor light emitting element 64a is outside the circuit board 32, and the second semiconductor light emitting element 64b is the circuit board. 32 is arranged inside.
Then, the connection wiring 520 on the insulating layer 510 is connected to the second bonding pad electrode 240 of the other first semiconductor light emitting element 64a in which the first bonding pad electrode 210 of a certain first semiconductor light emitting element 64a is disposed adjacent thereto. Connected through. The first bonding pad electrode 210 or the second bonding pad electrode 240 and the connection wiring 520 are connected by a bonding wire 65.
In addition, a portion of the connection wiring 520 that needs to be connected to the other two connection wirings 520 is connected by a low resistance chip resistor 66.

As described above, the plurality of first semiconductor light emitting elements 64 a are connected in series by the connection wiring 520. Similarly, a plurality of second semiconductor light emitting elements 64b are connected in series by a connection wiring 520. However, the plurality of first semiconductor light emitting elements 64a and the plurality of second semiconductor light emitting elements 64b are not connected to each other. This is for enabling lighting control of the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b individually.
That is, only ten second semiconductor light emitting elements 64b arranged inside the circuit board 32 are connected in series between the connection wiring terminals 520a and 520b. On the other hand, only ten first semiconductor light emitting elements 64a arranged outside the circuit board 32 are connected in series between the connection wiring terminals 520c and 520d. As a result, the illumination control unit 30 applies a voltage obtained by multiplying the forward voltage of the second semiconductor light emitting element 64b by the number connected in series between the connection wiring terminals 520a and 520b, and the second semiconductor light emitting element 64b. By causing a forward current to flow through, a plurality of second semiconductor light emitting elements 64b connected in series can be turned on simultaneously. The same applies to the connection wiring terminals 520c and 520d.

  In the present embodiment, as shown in FIG. 11A, ten first semiconductor light emitting elements 64a arranged on the right side, the center, and the left side of the circuit board 32 in the drawing, and each connected in series. The second semiconductor light emitting element 64b is connected in parallel between the connection wiring terminals 520a and 520b or between the connection wiring terminals 520c and 520d. Thus, by connecting a plurality of columns of the first semiconductor light emitting elements 64a or the second semiconductor light emitting elements 64b connected in series in parallel, all the first semiconductor light emitting elements 64a or the second semiconductor light emitting elements on the circuit board 32 are connected. The voltage supplied to the first semiconductor light-emitting element 64a or the second semiconductor light-emitting element 64b can be suppressed lower than when 64b are connected in series.

FIG. 12 is a diagram for further explaining a chip-on-board (COB) type circuit board 32 on which the semiconductor light-emitting elements (first semiconductor light-emitting element 64a and second semiconductor light-emitting element 64b) according to the present embodiment are directly mounted. FIG. 12A is an enlarged plan view showing a part of one semiconductor light emitting element installation portion 530. FIG. 12B is a cross-sectional view taken along line XIIB-XIIB in FIG.
On both surfaces of the circuit board 32, insulating layers 510 on which connection wirings 520 are formed are provided. The insulating layer 510 is removed so that the circuit board 32 is exposed in the semiconductor light emitting element installation portion 530 in which the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b are installed.

  A first semiconductor light emitting element 64a and a second semiconductor light emitting element 64b are disposed on the exposed circuit board 32 of the semiconductor light emitting element installation portion 530. The first bonding pad electrode 210 and the second bonding pad electrode 240 of the first semiconductor light emitting element 64a are connected to the connection wiring 520 formed on the insulating layer 510 by the bonding wire 65. Similarly, the third bonding pad electrode 400 and the fourth bonding pad electrode 410 of the second semiconductor light emitting element 64b are connected to the connection wiring 520 by the bonding wire 65, respectively.

As shown in FIG. 12B, the insulating layer 510 (including the connection wiring 520 formed on both surfaces of the insulating layer 510) is stacked on the circuit board 32 via the adhesive layer 540. And the part used as the semiconductor light-emitting element installation part 530 of the insulating layer 510 is removed so that the side surface may be conical, for example, and the circuit board 32 is exposed.
The material of the insulating layer 510 is not limited, and a known material such as resin or ceramic can be arbitrarily used. In particular, a glass epoxy obtained by impregnating a glass cloth with an epoxy resin is preferable.
The material of the connection wiring 520 is not limited, and a known material such as Cu or Al can be arbitrarily used.
The material of the adhesive layer 540 is not limited as long as it can be bonded to both the circuit board 32 and the insulating layer 510. You may join to the circuit board 32 by hot press using hot melt adhesives, such as an epoxy resin. You may affix on the circuit board 32 using a sticky adhesive.
Here, although the connection wiring 520 is formed on both surfaces of the insulating layer 510, the connection wiring 520 may be formed only on one surface.

The first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b are fixed to the circuit board 32 with resin, for example. Further, it is more preferable that an AuSn layer is formed on the back surface of the first semiconductor light emitting element 64a via a metal layer such as Al or Ni and fixed to the surface of the circuit board 32 by heat melting. The same applies to the second semiconductor light emitting element 64b.
Each n-type pad electrode and p-type pad electrode and the connection wiring 520 are connected by a bonding wire 65 such as gold.
Then, a sealing resin 550 is provided on the semiconductor light emitting element installation portion 530 so as to cover the first semiconductor light emitting element 64 a and the second semiconductor light emitting element 64 b and the bonding wire 65. As described above, the sealing resin 550 only needs to be made of a transparent resin that transmits light emitted from the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b. As the transparent resin, for example, a curable resin that seals so as to cover the concave portion, a curing agent that cures this, and further blended as necessary, for example, an antioxidant, a discoloration inhibitor, a photodegradation inhibitor, a reaction That contain a reactive diluent, an inorganic filler, a flame retardant, an organic solvent, and the like. Specific examples of the curable resin include silicone resin, epoxy resin, epoxy silicone hybrid resin, acrylic resin, and polyimide resin. Among these, from the viewpoint of heat resistance, a silicone resin and an epoxy resin are preferable, and a silicone resin is particularly preferable.

Such a structure can be manufactured, for example, as follows.
As the plate-like insulating layer 510, a copper foil having a thickness of 18 μm is formed on both sides of a glass epoxy having a thickness of 0.1 mm, and the copper foil is etched to form a connection wiring 520. In order to apply silver plating with a thickness of 2μm or more to the copper foil surface of the circuit pattern by the electroplating method, the circuit pattern on the front surface is all conductive with the circuit pattern on the back surface through the through hole. Then, the edge of the circuit board 32 is cut off to cut the edge of the circuit pattern. Then, an adhesive layer 540 having a thickness of 50 μm is formed on the back surface side using a hot melt adhesive.
Next, the part of the insulating layer 510 that becomes the semiconductor light emitting element installation portion 530 of the plate-like insulating layer 510 is removed by punching or the like.
Then, a highly reflective aluminum plate having a thickness of 0.7 mm and a plate-like insulating layer 510 are overlapped at a predetermined position and hot pressed. As a result, the highly reflective aluminum plate and the plate-like insulating layer 510 are firmly joined to form the COB circuit board 32.

Next, the first semiconductor light emitting element 64 a and the second semiconductor light emitting element 64 b are bonded to the exposed portion of the metal base of the circuit board 32. The first bonding pad electrode 210 and the second bonding pad electrode 240 of the first semiconductor light emitting element 64 a and the connection wiring 520 are connected by the bonding wire 65.
Thereby, a structure in which the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b are directly mounted on the circuit board 32, that is, a so-called COB can be formed.

In the illuminating device 20 thus manufactured, the density of photons (photon quantum density) immediately below 20 cm is 250 μmol / m ² / sec when red is applied to each of the first semiconductor light emitting elements 64a that emit blue light, and red. When 20 mA was applied to each of the light emitting second semiconductor light emitting elements 64b, the current was 150 μmol / m ² / sec.

  Further, the semiconductor light emitting device is not turned on, (I) left at 5 ° C. for 15 minutes, (II) raised to 60 ° C. in 15 minutes, (III) left at 60 ° C. for 15 minutes, (IV) in 15 minutes In a temperature cycle test in which the temperature cycle of decreasing the temperature to 5 ° C. and returning to (I) was repeated 1000 times, the inner surface of the transparent cover 12 (glass) of the lighting device 20 was cloudy and no condensation was observed. Further, in an environment of 30 ° C. and 95% RH (relative humidity), continuous lighting for 1000 hours was performed by flowing 10 mA to the first semiconductor light emitting element 64 a that emits blue light and 30 mA to the second semiconductor light emitting element 64 b that emits red light. In the test, no rust or non-lighting of the semiconductor light emitting element was observed in the lighting device 20, and the photon density was maintained at 98% of the initial value.

Note that in this embodiment mode, in order to extract light efficiently, a reflective surface may be provided on a side surface of the insulating layer 510 surrounding the semiconductor light emitting element installation portion 530. The reflective surface may be formed of a highly reflective metal film such as Al, or may be fitted with a metal ring made of Al or the like that fits into the shape of the semiconductor light emitting element installation portion 530.
Also in the present embodiment, as in the first embodiment, the reflection for setting the direction of the light emitted from the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b on the circuit board 32. A vessel 26 may be provided. The reflector 26 may be formed with a parabolic reflection surface, for example, corresponding to the semiconductor light emitting element installation portion 530. A reflector 26 may be provided for each of the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b constituting the pair, or the reflector 26 may be provided for each pair. Furthermore, when the direction of light is controlled only in the short or long direction of the circuit board 32, a slit-like reflector 26 may be used.

  Further, in the present embodiment, the low resistance chip resistor 66 is used in a portion where the other two connection wirings 520 are connected across the connection wiring 520, but the connection wirings 520 may be formed in multiple layers.

In the illumination devices 10 and 20 to which the present embodiment is applied, the heat generated by the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b is generated by the refrigerant in the refrigerant conduit 25 provided on the heat dissipation board 24 and the heat dissipation board 24. Released outside the cultivation room 60. Therefore, a large current can be supplied to the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b without causing a decrease in light emission efficiency and without a risk of deterioration, and can be operated at a high light output.
Since the insides of the lighting devices 10 and 20 are sealed to suppress the inflow of outside air, it is possible to suppress corrosion due to moisture in the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b due to intrusion of moisture. . Furthermore, if the interiors of the lighting devices 10 and 20 are filled with dry air or dry nitrogen, corrosion of the first semiconductor light emitting element 64a and the second semiconductor light emitting element 64b due to moisture can be further suppressed. For this reason, even a GaAlAs-based semiconductor light-emitting element that is easily corroded by moisture can be used as the lighting devices 10 and 20 for plant cultivation.
Moreover, since the illuminating devices 10 and 20 are filled with dry air or dry nitrogen, and the refrigerant conduit 25 is disposed inside the outside air, the refrigerant is provided in the high temperature and high humidity cultivation room 60. Even if it distribute | circulates, dew condensation does not occur, and corrosion by the dew condensation water of the thermal radiation board | substrate 24 and the refrigerant | coolant conduit | pipe 25 can be suppressed.

  In the present embodiment, since the male first pipe coupler 16 and the female second pipe coupler 17 can be connected by a simple operation, it is easy to connect and remove the plurality of lighting devices 10 and 20. The construction and change of the plant cultivation system 1 can be easily performed. And since the some illuminating devices 10 and 20 are connected by the piping member (The male 1st piping coupler 16 and the female 2nd piping coupler 17) used as the path | route of a refrigerant | coolant, it is necessary to provide the member for a connection separately There is no. Furthermore, the some illuminating devices 10 and 20 can be arrange | positioned closely, and the space of the cultivation room 60 can be utilized effectively.

DESCRIPTION OF SYMBOLS 1 ... Plant cultivation system 10, 20 ... Illuminating device, 11 ... Exterior cover, 12 ... Transparent cover, 13 ... 1st side cover, 14 ... 2nd side cover, 15 ... Piping joint, 16 ... 1st piping coupler, 17 DESCRIPTION OF SYMBOLS 2nd piping coupler, 21 ... Light emitting element package, 22, 32 ... Circuit board, 23 ... Insulating heat dissipation material, 24 ... Heat dissipation board, 25 ... Refrigerant conduit, 26 ... Reflector, 30 ... Lighting control part, 31 ... Illumination Control wiring, 40 ... refrigerant supply part, 41 ... refrigerant piping, 50 ... cultivation container, 60 ... cultivation room, 61 ... resin container, 62a, 62b ... lead part for anode, 63a, 63b ... lead part for cathode, 64a ... first 1 semiconductor light emitting element, 64b... Second semiconductor light emitting element

Claims (11)

A plurality of light emitting elements;
A casing having a light-transmitting window that transmits light emitted from the light-emitting element, and provided to cover the light-emitting element;
A heat dissipating board disposed inside the housing and dissipating heat generated by the light emitting element by conduction;
Mounted on the heat radiation substrate, comprising: a coolant conduit for the flow path of the refrigerant, and
The housing includes the refrigerant conduit inside the housing, and the inside of the housing is configured to suppress inflow of outside air ,
The heat radiating substrate has a portion into which the refrigerant conduit is inserted, is manufactured by extrusion molding of aluminum or an aluminum alloy, and is configured integrally with the refrigerant conduit to be inserted. apparatus.   The lighting device for plant cultivation according to claim 1, wherein the casing is filled with dry air or dry nitrogen.   The lighting device for plant cultivation includes connecting means for connecting the refrigerant conduit and an adjacent refrigerant conduit provided in an adjacent lighting device, and forming a refrigerant flow path between the adjacent refrigerant conduit and the refrigerant conduit. The lighting device for plant cultivation according to claim 1, further comprising:   The casing is a long box-shaped, one surface in the long direction constitutes the translucent window portion, and the other three surfaces in the long direction constitute a continuous exterior portion, 4. The lighting device for plant cultivation according to any one of claims 1 to 3, wherein the remaining two surfaces constitute side portions. The said exterior part is manufactured by extrusion molding of aluminum or aluminum alloy. The illuminating device for plant cultivation of Claim 4 characterized by the above-mentioned. The light emitting element is disposed on the light emitting device package, the light emitting device package is secured to the circuit board, in any one of claims 1 to 5 the circuit board is characterized in that it is fixed to the heat radiation substrate The lighting apparatus for plant cultivation of description. 7. The plant cultivation according to any one of claims 1 to 6 , wherein the light emitting element is directly attached to a metal base portion of a metal base circuit board, and the circuit board is fixed to the heat dissipation board. Lighting equipment. The light emitting device includes a light emitting element having an emission peak wavelength of 400-500 nm, plant cultivation according to any one of claims 1 to 7 emission peak wavelength; and a light emitting element of 655~675nm Lighting equipment. The light emitting element includes a compound semiconductor layer including at least a pn junction type light emitting part and a strain adjustment layer laminated on the light emitting part,
The light emitting unit, composition formula _{(Al X Ga 1-X)} Y In 1-Y P (0 ≦ X ≦ 0.1,0.37 ≦ Y ≦ 0.46) between the strained light emitting layer and a barrier layer made of Having a laminated structure,
The strain adjustment layer according to any one of claims 1 to 8, characterized in that it has a lattice constant smaller than that of the strained light emitting layer and the barrier layer with a transparent to the emission wavelength Lighting equipment for plant cultivation. The plant cultivation according to any one of claims 1 to 9 , further comprising a reflector that sets a light direction of the light emitting element between the light emitting element and the translucent window. Lighting equipment. A plurality of light-emitting elements, a light-transmitting window that transmits light emitted from the light-emitting elements, a housing provided so as to cover the light-emitting elements, and the light-emitting elements disposed inside the housing a heat dissipating substrate but that dissipated by conduction of heat generated, is mounted on the heat radiation substrate, comprising: a coolant conduit for the flow path of the refrigerant, and the heat dissipation substrate has a portion for inserting the coolant conduit, aluminum Or a plurality of lighting devices for plant cultivation that are manufactured by extrusion molding of an aluminum alloy and configured integrally with the refrigerant conduit to be inserted, and connect the refrigerant conduits adjacent to each other to form a refrigerant flow path.
A refrigerant supply unit for supplying refrigerant to the refrigerant conduits connected to the plurality of lighting devices for plant cultivation;
A plant cultivation system comprising: an illumination control unit that controls turning on and off of the light emitting elements of the plurality of lighting devices for plant cultivation.

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