JP7591202B2 - LED lighting sheet for cultivating animals and plants, LED lighting module for cultivating animals and plants, shelf board for cultivating shelves for animals and plants, cultivating shelves for animals and plants, and plant and animal cultivating factory - Google Patents

Description

The present disclosure relates to an LED lighting sheet for cultivating animals and plants, an LED lighting module for cultivating animals and plants, a shelf for cultivating shelves for cultivating animals and plants, a cultivating shelf for cultivating animals and plants, and an animal and plant cultivating factory.

In recent years, there has been a growing demand for lighting devices that use low-power LEDs as light sources, instead of conventional fluorescent lamps and high-pressure sodium lamps, as lighting devices used in animal and plant breeding factories.

One example of an animal and plant cultivation factory that uses lighting devices with LEDs as light sources is a plant cultivation device in which multiple straight tube plant cultivation lights with LEDs as light sources are arranged on the shelves of a plant cultivation shelf (see, for example, Patent Document 1).

An LED lighting device for growing plants and animals has also been proposed in which multiple LED chips are arranged on a flexible circuit board to form a planar light source (see, for example, Patent Document 2).

JP 2008-118957 A JP 2013-251230 A

The present disclosure provides an LED lighting sheet for cultivating animals and plants, capable of protecting LED chips, an LED lighting module for cultivating animals and plants, a shelf for cultivating shelves for cultivating animals and plants, a cultivating shelf for cultivating animals and plants, and an animal and plant cultivating factory.

The LED illumination sheet for cultivating animals and plants according to this embodiment is an LED illumination sheet for cultivating animals and plants, and includes a substrate film, a metal wiring section formed on the surface of the substrate film, an LED chip mounted on the metal wiring section, and a protective section that covers at least a portion of the side surface of the LED chip and protects the LED chip.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, the LED chip is mounted on the metal wiring section via a solder section, and the solder section extends from the back surface to the side surface of the LED chip, and the protective section may cover the solder section located to the side of the LED chip.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, the protective portion may include a central portion covering at least a portion of the surface of the LED chip, a curved portion covering at least a portion of the side surface of the LED chip, and a flat portion formed adjacent to the curved portion.

In the LED illumination sheet for growing animals and plants according to this embodiment, the central portion may cover the entire surface of the LED chip.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, the thickness of the central portion may be gradually increased toward the center of the LED chip.

In the LED illumination sheet for growing animals and plants according to this embodiment, the curved portion may cover the entire side surface of the LED chip.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, the thickness of the curved portion may gradually increase as it approaches the LED chip.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, in a cross section perpendicular to the light-emitting surface of the LED illumination sheet for cultivating animals and plants, the curved portion may have a concave shape that is recessed from the light-emitting surface side of the LED illumination sheet for cultivating animals and plants toward the surface opposite the light-emitting surface.

In the LED illumination sheet for growing animals and plants according to this embodiment, the curved portion may cover the solder portion located on the side of the LED chip.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, in a cross section perpendicular to the light-emitting surface of the LED illumination sheet for cultivating animals and plants, the portion of the solder part located to the side of the LED chip may have a curved shape that rises toward the light-emitting surface.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, in a cross section perpendicular to the light-emitting surface of the LED illumination sheet for cultivating animals and plants, the thickest part of the solder part does not have to be in contact with the side surface of the LED chip.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, when viewed from the light-emitting surface side of the LED illumination sheet for cultivating animals and plants, the portion of the solder part located to the side of the LED chip may be formed so as to surround a part of the side surface of the LED chip.

The LED illumination sheet for cultivating animals and plants according to this embodiment may further include a light-reflective insulating protective film arranged to cover the metal wiring portion, and the protective portion may cover the light-reflective insulating protective film.

In the LED illumination sheet for growing animals and plants according to this embodiment, the protective portion may cover the entire surface and side surfaces of the LED chip.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, the protective portion may have a transparent protective film.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, a gap may be formed between the transparent protective film and the side of the LED chip.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, the protective portion may further include an adhesive layer that bonds the LED chips and the transparent protective film.

In the LED illumination sheet for cultivating animals and plants according to this embodiment, the protective portion may cover the side surface of the LED chip with the adhesive layer.

In the LED illumination sheet for growing animals and plants according to this embodiment, 10 or more LED chips are arranged in series, and the rows of LED chips may be arranged in parallel in four or more rows.

In this embodiment of the LED lighting sheet for growing animals and plants, the thickness at the thickest part may be 5 mm or less.

The LED lighting module for cultivating animals and plants according to this embodiment is an LED lighting module for cultivating animals and plants, and includes the LED lighting sheet for cultivating animals and plants according to this embodiment, and a control unit electrically connected to the LED lighting sheet for cultivating animals and plants, and the control unit is externally connected to the LED lighting sheet for cultivating animals and plants.

In the LED lighting module for cultivating animals and plants according to this embodiment, a constant voltage may be applied from the control unit to the LED lighting sheet for cultivating animals and plants.

In the LED lighting module for cultivating plants and animals according to this embodiment, the control unit may be capable of controlling the dimming of the LED chip.

The shelf board for the animal/plant cultivation shelf according to this embodiment is a shelf board for the animal/plant cultivation shelf, and includes a base plate and an LED lighting sheet for the animal/plant cultivation according to this embodiment or an LED lighting module for the animal/plant cultivation according to this embodiment attached to the base plate.

The animal/plant cultivation shelf according to this embodiment is a shelf for cultivating animals and plants, and includes a shelf board, and the shelf board includes an LED lighting sheet for cultivating animals and plants according to this embodiment or an LED lighting module for cultivating animals and plants according to this embodiment attached to the underside of a substrate.

In the plant and animal growing shelf according to this embodiment, the LED lighting sheet for growing plants and animals may also be arranged on the side of the shelf board.

The animal and plant growing factory according to this embodiment includes a building and a shelf for growing the animals and plants according to this embodiment arranged inside the building.

This embodiment allows the LED chip to be protected.

FIG. 1 is a schematic diagram illustrating an LED lighting module according to one embodiment. FIG. 2 is a plan view showing an LED illumination sheet according to one embodiment. 3(a) and 3(b) are plan views showing modified examples of the LED illumination sheet. FIG. 4(a) is a graph showing the relationship between time and voltage when a constant voltage is applied to the LED illumination sheet from the control unit, and FIG. 4(b) is a graph showing the relationship between time and voltage when a pulse is applied to the LED illumination sheet as a comparative example. FIG. 5A is a cross-sectional view (cross-sectional view taken along line VA-VA in FIG. 2) showing an LED illumination sheet according to one embodiment. FIG. 5B is an enlarged view showing a protective portion of the LED illumination sheet according to one embodiment (an enlarged view corresponding to portion VB in FIG. 5A). FIG. 6 is a plan view (view taken in the direction of arrow VI in FIG. 5A) showing LED chips of an LED illumination sheet according to one embodiment. 7(a)-(i) are cross-sectional views showing a manufacturing method of an LED illumination sheet according to one embodiment. FIG. 8 is a schematic perspective view showing a plant growing factory according to one embodiment. FIG. 9 is a schematic perspective view of a plant growing shelf according to one embodiment. 10(a)-(b) are diagrams showing modified examples of plant growing shelves. FIG. 11 is a cross-sectional view showing a modified example of the LED illumination sheet according to the embodiment. FIG. 12 is a cross-sectional view showing a modified example of the LED illumination sheet according to the embodiment. FIG. 13 is a cross-sectional view showing a modified example of the LED illumination sheet according to the embodiment. FIG. 14 is a cross-sectional view showing a modified example of the LED illumination sheet according to the embodiment. FIG. 15 is a cross-sectional view showing a modified example of the LED illumination sheet according to the embodiment. FIG. 16 is a cross-sectional view showing a modified example of the LED illumination sheet according to the embodiment. FIG. 17 is a cross-sectional view showing a modified example of the LED illumination sheet according to the embodiment.

The LED lighting sheet for growing animals and plants according to this embodiment includes a substrate film, a metal wiring section formed on the surface of the substrate film, an LED chip mounted on the metal wiring section, and a protective section that covers at least a portion of the side surface of the LED chip to protect the LED chip.

Since the LED lighting sheet for cultivating animals and plants according to this embodiment is a sheet-shaped LED lighting device, the overall thickness can be made thinner than an LED bar light in which multiple straight tube LEDs are arranged. Therefore, the vertical spacing of the shelves of the animal and plant cultivation shelf can be narrowed to improve the yield of cultivated animals and plants per floor area of the animal and plant cultivation factory. In addition, since the thickness of the LED chip is smaller than the thickness of the straight LED tube, the LED lighting sheet can make the height difference between the place where the LED chip is arranged and the place where the LED chip is not arranged smaller than the height difference between the place where the straight LED tube is arranged and the place where the straight LED tube is not arranged. Therefore, since the shadow on the side of the LED chip is less likely to occur, the variation in the light irradiated to the animals and plants can be suppressed even when the animals and plants grow and come close to the LED lighting sheet. In the LED lighting device for cultivating animals and plants, suppressing the variation in the light irradiated to the animals and plants is important because it brings the size and quality of the cultivated animals and plants within a certain standard range and reduces non-conforming products. In the cultivation of plants and animals, it is important to control the light and heat irradiated to the plants and animals in the later stages of growth when the plants and animals grow and become more active in photosynthesis. The LED illumination sheet for cultivating plants and animals according to this embodiment can suppress the variation in the relatively strong light irradiated to the plants and animals when they are in close proximity to the LED illumination sheet.

In addition, in the LED illumination sheet for cultivating plants and animals according to this embodiment, the protective portion covers at least a portion of the side surface of the LED chip, protecting the LED chip. This makes it possible to prevent the LED chip from peeling off from the LED illumination sheet even if an operator touches the LED chip. This makes it possible to prevent the LED chip from falling onto the plant being cultivated, and to prevent the phosphor of the LED chip from coming into contact with the plant. This makes it possible to maintain good hygiene of the plant being cultivated.

The LED lighting module for growing animals and plants according to this embodiment includes an LED lighting sheet for growing animals and plants, and a control unit electrically connected to the LED lighting sheet, and the control unit is externally connected to the LED lighting sheet.

The LED lighting module for cultivating animals and plants according to this embodiment has an external control unit, so that the amount of cultivated animals and plants can be increased while suppressing a decrease in the yield of the cultivated animals and plants, and a good yield of animals and plants can be obtained. Heat generated locally near the control unit has a strong effect on animals and plants cultivated close to the control unit and has little effect on animals and plants cultivated far from the control unit. This can cause variation in the cultivation state of animals and plants, resulting in an increase in non-conforming products and a decrease in yield. The greater the light intensity of the LED lighting sheet, the greater the heat generated from the control unit. According to an LED lighting module in which the control unit is externally connected to the LED lighting sheet, the control unit can be installed anywhere, suppressing variation and obtaining a good yield.

The shelves for growing animals and plants, the shelves for growing animals and plants, and the animal and plant growing factory according to this embodiment are equipped with the LED lighting sheets or modules for growing animals and plants according to the above-mentioned embodiment, so that it is possible to obtain good yields of animals and plants.

The following is a detailed description of one embodiment with reference to the drawings. Each of the figures shown below is a schematic diagram. Therefore, the size and shape of each part are appropriately exaggerated to facilitate understanding. In addition, it is possible to carry out appropriate modifications within the scope of the technical concept. In each of the figures shown below, the same parts are given the same reference numerals, and some detailed descriptions may be omitted. In addition, the numerical values such as the dimensions of each member and the material names described in this specification are examples of embodiments, and are not limited to these, and can be appropriately selected and used. In this specification, terms that specify shapes and geometric conditions, such as parallel, orthogonal, and vertical, are intended to include substantially the same state in addition to their strict meanings. In this specification, animals and plants refer to animals and/or plants. In the following, for convenience, an example of growing (cultivating) plants using an LED lighting module will be described, but it can also be applied to growing animals within the scope of no contradiction.

(LED lighting module for plant growth)
An LED lighting module 10 for growing plants according to the present embodiment (hereinafter also referred to as the LED lighting module 10) shown in Fig. 1 is installed in a plant growing factory 90 (Fig. 8) that uses artificial light, as described below, to grow plants. Such an LED lighting module 10 includes an LED lighting sheet 20 for growing plants (hereinafter also referred to as the LED lighting sheet 20) and a control unit 40 electrically connected to the LED lighting sheet 20.

As shown in FIG. 2, the LED illumination sheet 20 has a plurality of LED chips 21 arranged on the light-emitting surface 20a side (the side facing the plant during use) of the sheet surface. By using such a direct-type LED illumination sheet 20, the light emitted from the LED chips 21 passes through the light-emitting surface 20a as it is and reaches the plant directly below, so that the amount of light can be increased to promote plant growth, and the thickness of the entire sheet can be reduced to make it difficult for a shadow to be generated on the side of the LED chips 21. Note that FIG. 2 shows an example of a direct-type LED illumination sheet 20, but this is not limited to this, and an edge-type LED illumination sheet with a light guide plate or the like interposed therebetween may also be used. The edge-type LED illumination sheet is easy to suppress the variation in the amount of light from the light-emitting surface 20a. The LED illumination sheet 20 in FIG. 2 includes a flexible wiring board 30 and a plurality of LED chips 21 regularly arranged on the flexible wiring board 30. By using such a flexible wiring board 30, an LED illumination sheet 20 with a relatively large sheet surface area can be obtained. Generally, in plant cultivation factories and plant cultivation shelves, multiple LED illumination sheets 20 are arranged and used, but if the positions of adjacent LED illumination sheets 20 vary, there is a risk of variation in the amount of light and a decrease in plant yield. LED illumination sheets 20 with a relatively large sheet surface area can reduce the number of LED illumination sheets 20 used, so that the variation in the amount of light due to the arrangement of multiple LED illumination sheets 20 can be suppressed. Note that FIG. 2 shows an example of an LED illumination sheet 20 with a flexible wiring board 30, but this is not limited to this, and an LED illumination sheet with a rigid wiring board may also be used. An LED illumination sheet with a rigid wiring board has high resistance to stress and is not easily damaged. Note that in FIG. 2, the light-reflective insulating protective film 34 and the transparent protective film 35 described later are omitted.

In this case, the LED chips 21 are arranged in a lattice pattern in a plan view within the flexible wiring board 30. That is, the LED chips 21 are arranged in a matrix pattern in multiple rows and columns, and N rows R of M LED chips 21 connected in series are arranged. For example, in FIG. 2, 14 LED chips 21 (M=14) are connected in series along the first arrangement direction (X direction) of the LED chips 21. Furthermore, the row R having these 14 LED chips 21 is arranged in parallel in 10 rows (N=10) along the second arrangement direction (Y direction) of the LED chips 21. Note that the number of LED chips 21 is not limited to this. Specifically, it is preferable to arrange the LED chips 21 in series in the first arrangement direction (X direction) in a number between 10 and 14 (14≧M≧10), and to arrange the row R in parallel in the second arrangement direction (Y direction) of the LED chips 21 in a number between 4 and 10 (10≧N≧4). By arranging 10 or more LED chips 21 in series, the LED chips 21 can be arranged at short intervals along the first arrangement direction (X direction), and the in-plane variation in the illuminance of the LED illumination sheet 20 can be suppressed, and the variation in the light irradiated to the plants can be suppressed. By arranging 14 or less LED chips 21 in series, the power consumption can be reduced, and the running costs such as the utility costs in the plant cultivation factory 90 can be reduced. In addition, by arranging the rows of the LED chips 21 in four or more rows in parallel in the second arrangement direction (Y direction) of the LED chips 21, even if a specific LED chip 21 is damaged, the damage does not spread to the LED chips 21 in other rows, and the illuminance of the entire LED illumination sheet 20 can be prevented from being extremely reduced. In addition, by limiting the range in which the illuminance of the LED illumination sheet 20 is reduced, the range in which non-conforming products may be generated can be limited, and the reduction in yield can be suppressed. In addition, when the LED lighting sheet 20 is a direct type, there is a high possibility that the LED chips 21 may be damaged by accidentally touching them too hard during installation or cleaning, so it is important from the perspective of risk management to take measures against damage. Furthermore, by arranging the LED chips 21 in parallel in 10 or fewer rows, it is possible to reduce power consumption and the running costs, such as utility costs, of the plant cultivation factory 90.

The LED illumination sheet 20 has a plurality of metal wiring parts 22, which are arranged along a first arrangement direction (X direction). The plurality of metal wiring parts 22 arranged along the first arrangement direction (X direction) correspond to each row R of the LED chips 21. The LED chips 21 are arranged so as to straddle a pair of metal wiring parts 22 adjacent to each other in the X direction. In addition, each terminal (not shown) of the LED chip 21 is electrically connected to a pair of metal wiring parts 22. The plurality of metal wiring parts 22 constitute a power supply part for the LED chips 21, and when power is supplied to the plurality of metal wiring parts 22, all of the LED chips 21 arranged in the row R are illuminated. The plurality of metal wiring parts 22 constitute a part of a metal wiring part 32 described later.

The spacing Px between the LED chips 21 in the first arrangement direction (X direction) is preferably 37 mm or more and 50 mm or less. The spacing Py between the LED chips 21 in the second arrangement direction (Y direction) is preferably 37 mm or more and 100 mm or less. By setting the spacing between the LED chips 21 within the above range, the brightness of the LED illumination sheet 20 can be made uniform across the surface, the variation in the light irradiated to the plants can be suppressed, and the power consumption of the LED illumination sheet 20 can be reduced.

It is preferable that the thickness of the LED illumination sheet 20 at its thickest part is 5 mm or less. By reducing the thickness of the LED illumination sheet 20 in this way, the vertical distance between the substrates 81 (Fig. 9) on which the LED illumination sheet 20 is installed can be narrowed, and this makes it possible to increase the number of substrates 81 per plant cultivation shelf 80 (Fig. 9). As a result, the plant yield per unit area can be increased. In addition, the variation in the relatively strong light irradiated to the plant when the plant and the LED illumination sheet 20 are in close proximity can be further suppressed.

The arrangement of the LED chips 21 is not limited to a lattice-point arrangement in plan view, and may be arranged in a staggered pattern in plan view as shown in FIG. 3(a). The LED chips 21 may not be arranged uniformly in the plane of the LED illumination sheet 20. For example, the density of the LED chips 21 may be increased in the peripheral portion of the LED illumination sheet 20. Specifically, as shown in FIG. 3(b), the LED chips 21 may be arranged in a lattice-point arrangement in the center of the LED illumination sheet 20 (lower portion of FIG. 3(b)), and the LED chips 21 may be arranged in a staggered pattern in the peripheral portion of the LED illumination sheet 20 (upper portion of FIG. 3(b)). This suppresses the decrease in brightness of the LED illumination sheet 20 in the peripheral portion of the LED illumination sheet 20, makes the brightness of the LED illumination sheet 20 uniform in the plane, and suppresses the variation in the light irradiated to the plants.

The overall shape of the LED lighting sheet 20 is rectangular in a plan view, but there are no particular limitations on the size or planar shape of the LED lighting sheet 20. The LED lighting sheet 20 has a high degree of freedom in processing the size and shape, so it can flexibly respond to various demands in this regard. In addition, by taking advantage of its flexibility, it can be attached to installation surfaces of various shapes, not just flat installation surfaces.

2, the length Lx of the LED illumination sheet 20 in the first arrangement direction (X direction) is preferably 500 mm or more and 700 mm or less, and more preferably 550 mm or more and 650 mm or less. The length Ly of the LED illumination sheet 20 in the second arrangement direction (Y direction) is preferably 300 mm or more and 500 mm or less, and more preferably 350 mm or more and 450 mm or less. By setting the size of the LED illumination sheet 20 within the above range, the LED illumination sheet 20 can be adapted to a general plant growth substrate 81 (FIG. 9), and the dead space of the substrate 81 can be reduced. In addition, since the size of each LED illumination sheet 20 is not excessively large, when a specific LED chip 21 is damaged, the influence on other LED chips 21 is minimized, and the illuminance of the entire shelf board 83 (FIG. 9) for plant growth shelves is prevented from decreasing drastically, and the range in which the illuminance decreases can be limited.

Next, the control unit 40 will be described. As shown in FIG. 1, the control unit 40 supplies power to the LED illumination sheet 20 and controls the light emission of the LED illumination sheet 20. The control unit 40 is detachably connected to the LED illumination sheet 20 via a first connector 44A provided on the LED illumination sheet 20. That is, the control unit 40 is configured separately from the LED illumination sheet 20 and is externally connected to the LED illumination sheet 20. That is, the control unit 40 is not integrated with the LED illumination sheet 20. This allows the control unit 40, which is a heat source, to be separated from the LED illumination sheet 20, and prevents the heat from the control unit 40 from affecting plant growth.

The control unit 40 also has a power input unit 41, an AC/DC converter (driver) 42, and a PWM control unit 43. An AC voltage having an arbitrary voltage of, for example, 100V to 240V is supplied to the power input unit 41. The AC/DC converter 42 converts the AC voltage of 100V to 240V into a constant voltage (for example, 44V) DC voltage. The PWM control unit 43 adjusts the light intensity of the LED chips 21 of the LED illumination sheet 20 by arbitrarily changing the pulse width of the constant voltage waveform from the AC/DC converter 42. In other words, the PWM control unit 43 also serves as a dimming control unit that controls the dimming of the LED illumination sheet 20. The constant voltage output from the PWM control unit 43 is applied to the LED illumination sheet 20 via the first connector 44A.

By applying a constant voltage from the PWM control unit 43 of the control unit 40 to the LED illumination sheet 20, it becomes possible to adjust the brightness of the LED chips 21, unlike when a rectified pulse voltage is applied directly to the LED illumination sheet 20. That is, the PWM control unit 43 can arbitrarily control the illuminance of the LED chips 21 by appropriately changing the duty ratio of the DC voltage from the AC/DC converter 42. For example, as shown in FIG. 4(a), the PWM control unit 43 can reduce the illuminance of the LED chips 21 by suppressing the duty ratio of the constant voltage from the AC/DC converter 42 from 100% (solid line) to 50% (dotted line).

By appropriately adjusting the illuminance of the LED chips 21 in this way, the illuminance of the LED lighting sheet 20 can be adjusted according to the growth stage of the plant, and the degree of growth of the plant can be adjusted. For example, the illuminance of the LED lighting sheet 20 can be lowered in the early growth stage when the leaves of the plant are small, and the illuminance of the LED lighting sheet 20 can be higher in the later growth stage when the leaves of the plant are large. Alternatively, the illuminance of the LED lighting sheet 20 can be increased in the early growth stage when the plant is short and the distance between the plant and the LED chips 21 is large, and the illuminance of the LED lighting sheet 20 can be lowered in the later growth stage when the plant is tall and the distance between the plant and the LED chips 21 is small. As another example of adjusting the illuminance of the LED lighting sheet 20, the illuminance can be increased for plants that require high illuminance, and decreased for plants that can be grown even with low illuminance. The illuminance can be increased when the plant is to be shipped earlier, and decreased when the plant is to be shipped later.

In addition, by applying a constant voltage from the PWM control unit 43 to the LED illumination sheet 20, the integrated light quantity per unit time from the LED illumination sheet 20 can be increased. That is, for example, the integrated light quantity when a constant voltage is applied to the LED illumination sheet 20 (the area of the shaded portion in FIG. 4(a)) can be made larger than the integrated light quantity when a voltage is applied in pulses as a comparative example (the area of the shaded portion in FIG. 4(b)). This increases the luminous efficiency of the light from the LED illumination sheet 20 and improves plant growth efficiency.

Referring again to FIG. 1, the LED lighting sheet 20 is provided with a regulator 45. In this case, the regulator 45 is provided corresponding to each row of the LED chips 21, and specifically, ten regulators 45 are provided corresponding to the ten rows of the LED chips 21. The regulator 45 plays a role in keeping the current flowing through the LED chips 21 in each row constant. This makes it possible to prevent excessive current from flowing through the LED chips 21 in other rows even if one LED chip 21 is damaged, and to prevent the LED chips 21 in the other rows from being damaged. As a result, it is possible to prevent the illuminance of the entire LED lighting sheet 20 from decreasing extremely, and to suppress the variation in the light irradiated to the plants. In addition, the regulator 45 can control the amount of current controlled by the resistance value connected for each row, and for example, by changing the control resistance value of the first row and the last row, it is possible to increase the output only of the peripheral rows. Normally, the aim is to ensure uniformity by laying the LED lighting sheets 20 close together without any gaps, but even if the LED lighting sheets 20 are spaced 5 to 10 cm apart from each other from the standpoint of cost or breathability, the effect of eliminating the seams can be expected.

Furthermore, the LED illumination sheet 20 is provided with a power supply line 46 branching off from the first connector 44A. Also, a second connector 44B is provided on the LED illumination sheet 20. The power supply line 46 is not electrically connected to the LED chips 21 of the LED illumination sheet 20, but is electrically connected to the wiring of another LED illumination sheet 200 having the same configuration as the LED illumination sheet 20. That is, the power supply line 46 is detachably connected to the wiring of the LED illumination sheet 200 via the second connector 44B and another first connector 44A provided on the other LED illumination sheet 200. The current from the power supply line 46 is supplied to the other LED illumination sheet 200 via the second connector 44B and the other first connector 44A. This allows the two LED illumination sheets 20, 200 to be connected, and the two LED illumination sheets 20, 200 to be controlled simultaneously by one control unit 40. By being able to control multiple LED illumination sheets 20 simultaneously with one control unit 40, the number of control units 40, which are heat generating sources, can be reduced, making it less likely that variations in plant growth due to heat from the control units 40 will occur, and reducing yield declines.

(Each component of the LED lighting sheet)
Next, each member constituting the LED illumination sheet 20 will be described. As shown in Fig. 5A, the LED illumination sheet 20 includes a flexible wiring board 30 and a plurality of LED chips 21 arranged on the flexible wiring board 30. The flexible wiring board 30 includes a flexible substrate film 31 and a metal wiring section 32 formed on the surface (the surface on the light-emitting surface 20a side) of the substrate film 31. The metal wiring section 32 is laminated on the substrate film 31 via an adhesive layer 33.

Each LED chip 21 is mounted in a manner that allows electrical continuity with the metal wiring section 32. In this LED illumination sheet 20, the LED chips 21 are mounted on the flexible wiring board 30, so that multiple LED chips 21 can be arranged at a desired high density.

A light-reflective insulating protective film 34 is formed to cover the LED lighting sheet 20 except for the area where the LED chip 21, regulator 45, and connector 44 are provided and the surrounding area. This light-reflective insulating protective film 34 is arranged to cover the metal wiring section 32. The light-reflective insulating protective film 34 is a layer that combines an insulating function that contributes to improving the migration resistance of the LED lighting sheet 20 and a light-reflecting function that contributes to improving the light environment created by the LED lighting sheet 20. This layer is formed from an insulating resin composition containing a white pigment. If the migration resistance and light-reflecting functions can be obtained only with the metal wiring section 32 and the transparent protective film 35 described below, a structure without the light-reflective insulating protective film 34 is also possible.

A protective section 35A is provided that covers the light-reflective insulating protective film 34 and the LED chip 21 to protect the LED chip 21. The protective section 35A has a transparent protective film 35. This transparent protective film 35 is a resin film that is formed on the outermost surface (the surface closest to the light-emitting surface 20a) of the LED illumination sheet 20 mainly to ensure waterproofing of the LED illumination sheet 20. The transparent protective film 35 according to this embodiment may be formed, for example, by a method in which a transparent resin composition is sprayed by a spray process (hereinafter referred to as the "spray coating method"), or by a method in which a curtain coating method is used.

A solder portion 36 is provided on the metal wiring portion 32. Each LED chip 21 is electrically connected to the metal wiring portion 32 via the solder portion 36. Each LED chip 21 may be mounted on the metal wiring portion 32 via a conductive resin.

(Substrate film)
A flexible resin film can be used for the substrate film 31 shown in Fig. 5A. In this specification, "flexible" means "capable of being bent to a radius of curvature of at least 1 m or less, preferably 50 cm, more preferably 30 cm, further preferably 10 cm, and particularly preferably 5 cm."

The material for the substrate film 31 may be a thermoplastic resin with high heat resistance and insulating properties. Examples of such resins include polyimide resin (PI) and polyethylene naphthalate (PEN), which have excellent heat resistance, dimensional stability when heated, mechanical strength, and durability. Among them, polyethylene naphthalate (PEN) whose heat resistance and dimensional stability have been improved by applying a heat resistance improvement treatment such as annealing treatment can be preferably used. Polyethylene terephthalate (PET) whose flame retardancy has been improved by adding a flame retardant inorganic filler or the like may also be used.

The thickness of the substrate film 31 is not particularly limited, but it is preferable that the thickness is generally 10 μm or more and 500 μm or less, and preferably 50 μm or more and 250 μm or less, from the viewpoints of not becoming a bottleneck in the heat dissipation path, having heat resistance and insulating properties, and balancing the manufacturing costs. In addition, it is preferable that the thickness is within the above thickness range from the viewpoint of maintaining good productivity when manufacturing using the roll-to-roll method.

(Adhesive Layer)
Any known resin adhesive can be appropriately used as the adhesive for forming the adhesive layer 33. Among these resin adhesives, urethane-based, polycarbonate-based, silicone-based, acrylic-based, or epoxy-based adhesives can be particularly preferably used.

(Metal wiring part)
The metal wiring portion 32 is a wiring pattern formed by a conductive base material such as a metal foil on the surface (the surface on the light-emitting surface 20a side) of the substrate film 31. The metal wiring portion 32 is preferably formed by a dry lamination method on the surface of the substrate film 31 via an adhesive layer 33. The metal wiring portion 32 includes the above-mentioned multiple metal wiring portions 22. The multiple metal wiring portions 22 include a first metal wiring portion 22A and a second metal wiring portion 22B arranged at a distance from the first metal wiring portion 22A. The first metal wiring portion 22A and the second metal wiring portion 22B are equipped with an LED chip 21, and the LED chip 21 is electrically connected to the first metal wiring portion 22A and the second metal wiring portion 22B. The LED chip 21 is turned on by the power supplied to the first metal wiring portion 22A and the second metal wiring portion 22B.

The metal wiring section 32 is preferably made of a material that combines high levels of heat dissipation and electrical conductivity, and can be made of copper foil, for example. In this case, heat dissipation from the LED chips 21 is stabilized and an increase in electrical resistance is prevented, so that the variation in light emission between the LED chips 21 is reduced, enabling stable light emission. The life of the LED chips 21 is also extended. Furthermore, deterioration of peripheral components such as the substrate film 31 due to heat can be prevented, so the product life of the LED illumination sheet 20 can be extended. Examples of metals that form the metal wiring section 32 include the above-mentioned copper, as well as aluminum, gold, silver, and other metals.

The thickness of the metal wiring portion 32 may be set appropriately depending on the magnitude of the withstand current required for the flexible wiring board 30. However, in order to suppress warping due to thermal contraction of the substrate film 31 during solder processing using a reflow method or the like, it is preferable that the thickness of the metal wiring portion 32 is 10 μm or more. On the other hand, it is preferable that the thickness of the metal wiring portion 32 is 50 μm or less, which allows the flexible wiring board 30 to maintain sufficient flexibility and also prevents a decrease in handleability due to an increase in weight.

(Solder part)
The solder portion 36 is for joining the metal wiring portion 32 and the LED chip 21. This solder joining can be performed by a reflow method. As shown in FIG. 5B, the solder portion 36 according to this embodiment extends from the back surface 21c to the side surface 21b of the LED chip 21. In addition, in a cross section perpendicular to the light-emitting surface 20a of the LED illumination sheet 20, the portion of the solder portion 36 located on the side of the LED chip 21 has a curved shape that rises toward the light-emitting surface 20a. In this embodiment, the portion of the solder portion 36 located on the side of the LED chip 21 is formed in a substantially semicircular shape in a cross section perpendicular to the light-emitting surface 20a of the LED illumination sheet 20. In this specification, the "cross section perpendicular to the light-emitting surface of the LED illumination sheet" means a cross section along a direction (Z direction) perpendicular to the first arrangement direction (X direction) and the second arrangement direction (Y direction).

Also, as shown in FIG. 5A and FIG. 5B, in a cross section perpendicular to the light-emitting surface 20a of the LED illumination sheet 20, the thickest part A of the solder part 36 is not in contact with the side surface 21b of the LED chip 21. As a result, as shown in FIG. 5B, the transparent protective film 35 is interposed between the side surface 21b of the LED chip 21 and the solder part 36. Therefore, the adhesion between the transparent protective film 35 and the LED chip 21 can be improved. As a result, the transparent protective film 35 can effectively protect the LED chip 21. Also, since the transparent protective film 35 is interposed between the side surface 21b of the LED chip 21 and the solder part 36, even if a worker touches the LED chip 21, the transparent protective film 35 can absorb the force applied to the LED chip 21, and the LED chip 21 can be effectively prevented from peeling off from the LED illumination sheet 20.

Furthermore, as shown in FIG. 6, when viewed from the light-emitting surface 20a side, the portion of the solder section 36 located to the side of the LED chip 21 is formed so as to surround a part of the side surface 21b of the LED chip 21. This improves the bonding strength between the LED chip 21 and the solder section 36. This makes it possible to prevent the LED chip 21 from peeling off from the solder section 36.

On the other hand, as shown in FIG. 5B, the portion of the solder portion 36 located on the back surface 21c side of the LED chip 21 extends continuously onto the metal wiring portion 32. As will be described later, such a shape of the solder portion 36 is formed by pressing the solder 36a (see FIG. 7(g)-(h)) against the LED chip 21 and crushing it when forming the solder portion 36 by the reflow method. Although not shown, the portion of the solder portion 36 located on the back surface 21c side of the LED chip 21 may be composed of a plurality of parts spaced apart from each other. That is, there may be an area on the back surface 21c side of the LED chip 21 where the solder portion 36 is not formed. As described above, when forming the solder portion 36, the solder 36a is pressed against the LED chip 21 and crushed. As a result, the solder 36a is pushed out from the back surface 21c side of the LED chip 21, and an area on the back surface 21c side of the LED chip 21 where the solder portion 36 is not formed may be formed. Soldering may also be done using a laser.

(LED chip)
The LED chip 21 is a light-emitting element that utilizes light emission at a PN junction where a P-type semiconductor and an N-type semiconductor are joined. The LED chip 21 may have a structure in which a P-type electrode and an N-type electrode are provided on the upper and lower surfaces of the element, respectively, or may have a structure in which both a P-type electrode and an N-type electrode are provided on one surface of the element.

It is also preferable to select LED chips 21 with high luminous efficiency. Specifically, it is preferable to use LED chips 21 with a luminous efficiency of 150 lm/W or more, and it is even more preferable to use LED chips 21 with a luminous efficiency of 180 lm/W or more. By increasing the luminous efficiency of the LED chips 21 to 150 lm/W or more, it is possible to reduce the number (density) of LED chips 21 mounted and reduce heat generated by Joule heat from the LED chips 21, which makes it difficult for variations in plant growth due to heat from the LED chips 21 to occur, and suppresses a decrease in yield.

As described above, the LED lighting sheet 20 has the LED chips 21 directly mounted on the metal wiring section 32, which has high heat dissipation properties. This allows the excess heat generated when the LED chips 21 are turned on to be quickly diffused through the metal wiring section 32 and sufficiently dissipated to the outside of the LED lighting sheet 20 via the substrate film 31, even when the LED chips 21 are arranged at high density. This makes it difficult for the heat from the LED chips 21 to cause variations in plant growth, and suppresses a decrease in yield.

(Light-reflective insulating protective film)
The light-reflective insulating protective film 34 is a layer formed in an area excluding the area where the LED chip 21 is provided and the surrounding area. The light-reflective insulating protective film 34 is a so-called resist layer that has sufficient insulation properties to improve the migration resistance of the flexible wiring board 30, and is also a light-reflecting layer that has light reflectivity that contributes to improving the luminance of the light environment created by the LED illumination sheet 20.

The light-reflective insulating protective film 34 can be formed from various resin compositions that contain a urethane-based resin as a base resin and further contain a white pigment made of an inorganic filler such as titanium oxide. As the base resin of the resin composition used to form the light-reflective insulating protective film 34, in addition to the urethane-based resin, an acrylic polyurethane resin, a polyester resin, a phenolic resin, etc. can be appropriately used. As the base resin of the resin composition that forms the light-reflective insulating protective film 34, it is more preferable to use a resin that is the same as or similar to the resin composition that forms the transparent protective film 35 as the base resin. For the transparent protective film 35, as described later, it is preferable to use an acrylic polyurethane resin as the main material resin. Therefore, when the base resin of the resin composition that forms the transparent protective film 35 is an acrylic polyurethane resin, it is more preferable that the base resin of the resin composition for forming the light-reflective insulating protective film 34 is a urethane resin or an acrylic polyurethane resin.

The inorganic filler to be contained as a white pigment in the resin composition forming the light-reflective insulating protective film 34 may be at least one selected from titanium oxide, alumina, barium sulfate, magnesia, aluminum nitride, boron nitride, barium titanate, kaolin, talc, calcium carbonate, zinc oxide, silica, mica powder, powdered glass, powdered nickel, and powdered aluminum.

The thickness of the light-reflective insulating protective film 34 is 5 μm or more and 50 μm or less, and more preferably 7 μm or more and 20 μm or less. If the thickness of the light-reflective insulating protective film 34 is less than 5 μm, the light-reflective insulating protective film becomes thin, particularly at the edge portions of the metal wiring portion 32, and if the metal wiring is not covered and is exposed, there is a high risk that the insulation properties will not be maintained. On the other hand, from the viewpoint of protecting the light-reflective insulating protective film 34 from bending of the substrate during handling, transportation, etc., it is preferable that the thickness of the light-reflective insulating protective film 34 is 50 μm or less.

The light-reflective insulating protective film 34 preferably has an average light reflectance of 65% or more in the wavelength range of 400 nm or more and 780 nm or less, more preferably 70% or more, and even more preferably 80% or more. For example, by incorporating 20 parts by mass or more of titanium oxide per 100 parts by mass of a urethane-based or acrylic-based polyurethane base resin, the LED illumination sheet 20 can have the light reflectance of the light-reflective insulating protective film 34 of 75% or more when the thickness of the film is 8 μm.

(Transparent protective film)
The transparent protective film 35 is formed on the outermost surface of the LED illumination sheet 20 so as to cover the LED chips 21. The transparent protective film 35 is waterproof and transparent. The waterproof property of the transparent protective film 35 can prevent water from entering the inside of the device when the LED illumination sheet 20 is used as a light source for growing plants. The transparent protective film 35 can also prevent the LED chips 21 from peeling off from the LED illumination sheet 20.

The transparent protective film 35 can be formed from various resin compositions with an acrylic polyurethane resin or the like as the base resin. For example, the transparent protective film 35 may be formed from a two-component curing acrylic polyurethane resin containing fluorine. In addition to acrylic polyurethane resin, urethane resin, polyester resin, phenol resin, etc. can be appropriately used as the base resin of the resin composition used to form the transparent protective film 35. It is more preferable that the base resin of the resin composition forming the transparent protective film 35 is the same or similar resin as the resin composition forming the light-reflective insulating protective film 34. A preferred specific combination is a combination in which the base resin of the resin composition forming the light-reflective insulating protective film 34 is a urethane resin, and the same resin forming the transparent protective film 35 is an acrylic polyurethane resin.

Next, the transparent protective film 35 according to this embodiment will be described in more detail with reference to FIG. 5B. As shown in FIG. 5B, the transparent protective film 35 according to this embodiment covers the entire surface 21a (the surface on the light-emitting surface 20a side) and the side surface 21b of the LED chip 21. In this case, the transparent protective film 35 includes a central portion 35a covering the surface 21a of the LED chip 21, a curved portion 35b formed around the central portion 35a and covering the side surface 21b of the LED chip 21, and a flat portion 35c formed adjacent to the curved portion 35b. Of these, the central portion 35a covers the entire surface 21a of the LED chip 21. This makes it possible to reliably protect the phosphor 21d, which may be disposed approximately at the center of the surface 21a of the LED chip 21, from moisture scattered during plant growth. In addition, since the central portion 35a covers the entire surface 21a of the LED chip 21, when the LED illumination sheet 20 is used in a plant growth factory, it is possible to suppress contact of the grown plant with the phosphor 21d. Furthermore, because the central portion 35a covers the entire surface 21a of the LED chip 21, it is possible to prevent the phosphor 21d of the LED chip 21 from falling onto the plant being grown, and to prevent the phosphor 21d from coming into contact with the plant. This makes it possible to maintain good hygiene of the plant being grown.

The thickness of the central portion 35a is formed so that it gradually becomes thicker on the surface 21a of the LED chip 21 toward the center of the LED chip 21. This allows the thickness of the portion of the central portion 35a that covers the phosphor 21d that may be placed approximately in the center of the surface 21a of the LED chip 21 to be increased. This makes it possible to more reliably protect the phosphor 21d that may be placed approximately in the center of the surface 21a of the LED chip 21 from moisture that is dispersed during plant growth.

In addition, the thickness of the thickest part of the central portion 35a of the transparent protective film 35 is 5 μm or more and 40 μm or less, preferably 15 μm or more and 30 μm or less, and more preferably 20 μm or more and 25 μm or less. By making the thickness of the thickest part of the central portion 35a 40 μm or less, the LED illumination sheet 20 can effectively maintain good flexibility, thinness, light weight, and good optical properties required for plant cultivation applications. In addition, by making the thickness of the thickest part of the central portion 35a 10 μm or more, the LED illumination sheet 20 can be provided with sufficient waterproofing required for plant cultivation applications.

The curved portion 35b of the transparent protective film 35 covers the entire side surface 21b of the LED chip 21. This prevents the LED chip 21 from peeling off from the solder portion 36 even if an operator touches the LED chip 21.

The thickness of the curved portion 35b is also formed to gradually increase as it approaches the LED chip 21. This makes it possible to prevent a large force from being applied locally to the joint between the LED chip 21 and the solder portion 36 even if an operator touches the LED chip 21, and more effectively prevents the LED chip 21 from peeling off from the solder portion 36.

The curved portion 35b has a concave shape that is recessed from the light-emitting surface 20a side toward the surface opposite the light-emitting surface 20a in a cross section perpendicular to the light-emitting surface 20a of the LED illumination sheet 20. This effectively prevents the transparent protective film 35 from being damaged due to the force applied to the LED chip 21, even if an operator touches the LED chip 21. In this case, the radius of curvature r of the concave shape may be, for example, about 200 μm or more and 5000 μm or less.

Furthermore, the curved portion 35b covers the solder portion 36 located on the side of the LED chip 21. This makes it possible to protect the solder portion 36 from moisture that scatters during plant growth. In addition, since the solder portion 36 is covered by the curved portion 35b of the transparent protective film 35, it is possible to prevent the grown plant from coming into contact with the solder portion 36. Furthermore, since the solder portion 36 is covered by the curved portion 35b, it is possible to prevent the solder portion 36 from peeling off from the LED chip 21. In particular, in this embodiment, the portion of the solder portion 36 located on the side of the LED chip 21 is formed in an approximately semicircular shape. This can reduce the bonding area between the portion of the solder portion 36 located on the side of the LED chip 21 and the side surface 21b of the LED chip 21. Therefore, there is a possibility that the bonding strength between the portion of the solder portion 36 located on the side of the LED chip 21 and the side surface 21b of the LED chip 21 may be reduced. In this embodiment, the solder portion 36 is covered by the curved portion 35b of the transparent protective film 35, so that even if the portion of the solder portion 36 located to the side of the LED chip 21 is formed in a substantially semicircular shape, the solder portion 36 can be effectively prevented from peeling off from the LED chip 21. This can prevent the solder from coming into contact with the plant. This allows the sanitary condition of the plant to be maintained in good condition.

The flat portion 35c of the transparent protective film 35 has a substantially constant thickness. The thickness of the flat portion 35c is 5 μm or more and 40 μm or less, preferably 15 μm or more and 30 μm or less, and more preferably 20 μm or more and 25 μm or less. By making the thickness of the flat portion 35c 40 μm or less, the LED illumination sheet 20 can effectively maintain good flexibility, thinness, and lightness. In addition, by making the thickness of the flat portion 35c 5 μm or more, the LED illumination sheet 20 can be provided with sufficient waterproofing required for plant cultivation applications.

The surface of the transparent protective film 35 described above may be hydrophilic. As a result, when water adheres to the transparent protective film 35, the adhered water is distributed so as to spread along the surface of the transparent protective film 35. This makes it possible to prevent the adhered water from forming droplets and remaining at positions on the surface 21a of the LED chip 21 that correspond to the phosphor 21d. As a result, the good optical characteristics of the LED illumination sheet 20 can be effectively maintained.

The water resistance of the LED lighting sheet 20 due to the transparent protective film 35 is not particularly limited as long as it is possible to suppress deterioration of the LED chips 21 when water for plant growth is sprayed onto the LED lighting sheet 20. It is preferable that such water resistance exhibits IPX4 or higher in the waterproof and dustproof protection standard established by the IEC (International Electrotechnical Commission). Waterproofness of IPX4 or higher is a level at which the LED chips 21 are not adversely affected by water splashes from any direction. Specifically, it is a level at which the LED chips 21 are not adversely affected when water is sprayed from a watering nozzle at a rate of 10 L/min for 5 minutes over the entire range of ±180° from the normal direction of the LED lighting sheet 20.

(Manufacturing method of LED illumination sheet)
Next, a method for manufacturing the LED illumination sheet 20 according to this embodiment will be described with reference to FIGS.

First, the substrate film 31 is prepared (FIG. 7(a)). Next, a metal foil 32A such as copper foil, which is the material of the metal wiring portion 32, is laminated on the surface of the substrate film 31 (FIG. 7(b)). The metal foil 32A is adhered to the surface of the substrate film 31 by an adhesive layer 33 such as a urethane adhesive. Alternatively, the metal foil 32A may be formed directly on the surface of the substrate film 31 by electrolytic plating or vapor phase film formation (sputtering, ion plating, electron beam deposition, vacuum deposition, chemical deposition, etc.). Alternatively, the metal foil 32A may be formed by directly welding the substrate film 31 to the metal foil 32A.

Next, an etching mask 37 patterned into the shape required for the metal wiring section 32 is formed on the surface of the metal foil 32A (FIG. 7(c)). This etching mask 37 is provided so that the portion of the metal foil 32A that corresponds to the wiring pattern that will become the metal wiring section 32 is not corroded by the etching solution. There are no particular limitations on the method for forming the etching mask 37; for example, the etching mask 37 may be formed by exposing a photoresist or dry film to light through a photomask and then developing it, or the etching mask may be formed on the surface of the metal foil 32A by a printing technique such as an inkjet printer.

Next, the metal foil 32A located in the areas not covered by the etching mask 37 is removed using an immersion liquid (Figure 7(d)). This removes the parts of the metal foil 32A other than the areas that will become the metal wiring portion 32.

Then, the etching mask 37 is removed using an alkaline stripping solution. This removes the etching mask 37 from the surface of the metal wiring portion 32 (Figure 7 (e)).

Then, a light-reflective insulating protective film 34 is laminated on the metal wiring portion 32 (FIG. 7(f)). The light-reflective insulating protective film 34 can be formed by any coating means that can uniformly coat the material resin composition that constitutes the light-reflective insulating protective film 34, and can be formed by, for example, screen printing, offset printing, dip coating, brush coating, or other methods. Alternatively, the light-sensitive insulating protective film material can be coated on the entire surface, and only the necessary areas can be exposed to light through a photomask and then developed.

Next, the LED chip 21, the regulator 45 parts, and the connector 44 are mounted on the metal wiring part 32 (FIGS. 7(g)-(h)). In FIG. 7(h) and FIG. 7(i) described later, the regulator 45 parts are not shown in order to clarify the drawings. In this case, the LED chip 21 is joined to the metal wiring part 32 by soldering via the solder part 36. At this time, first, the solder 36a is stacked on the metal wiring part 32 (FIG. 7(g)). Next, the LED chip 21 is placed on the solder 36a (FIG. 7(h)). As a result, the solder 36a is pressed against the LED chip 21 and crushed, and the solder 36a is formed so as to extend from the back surface 21c to the side surface 21b of the LED chip 21. Next, the solder 36a is heated in a reflow furnace (not shown), and the LED chip 21 is mounted on the metal wiring part 32 via the solder part 36. In this case, the portion of the solder portion 36 located to the side of the LED chip 21 is formed into a substantially semicircular shape. Note that this soldering process may be performed using a laser method or conductive resin bonding.

Next, a transparent protective film 35 is formed so as to cover the light-reflective insulating protective film 34, the LED chip 21, the regulator 45 components, and the connector 44 (FIG. 7(i)). The transparent protective film 35 is preferably formed by a spray coating method or a curtain coating method. The transparent protective film 35 can be formed by, for example, spraying a coating liquid for spray coating treatment containing an acrylic polyurethane resin onto a desired area on the flexible wiring board 30 with a spray coater to form a coating film. The transparent protective film 35 can be formed by, for example, dropping a coating liquid for curtain coating treatment containing an acrylic polyurethane resin onto a desired area on the flexible wiring board 30 with a curtain coater to form a coating film. In these cases, the thickness of the transparent protective film 35 can be kept within a predetermined range, and the shape of the transparent protective film 35 can be easily made to follow the shape of the LED chip 21. At this time, by appropriately adjusting the conditions for the spray coating method or curtain coating method, a transparent protective film 35 including a central portion 35a, a curved portion 35b, and a flat portion 35c is formed (see FIG. 5B).

The LED illumination sheet 20 according to this embodiment can be manufactured not only by the above-mentioned method, but also by a known method for manufacturing a flexible wiring board for LED chips, or various LED modules in which LED chips are mounted on the flexible wiring board.

(Plant cultivation factories and plant cultivation shelves)
8 is a diagram showing a schematic configuration of a plant cultivation factory 90 using the LED illumination sheet 20 according to this embodiment. The plant cultivation factory 90 includes a building 91 and cultivation shelves 80 for multiple plants arranged inside the building 91.

9, the plant cultivation shelf 80 has a plurality of (four) supports 82 and a plurality of substrates 81 arranged at intervals in the vertical direction along the supports 82. The upper surface of each substrate 81 except the top substrate 81 is provided with a culture medium area for cultivating the plant PL. The lower surface of each substrate 81 except the bottom substrate 81 constitutes a ceiling surface with respect to the substrate 81 located below the substrate 81, and the LED illumination sheet 20 is arranged in parallel. In this case, the control unit 40 is arranged at a location sufficiently distant from the LED illumination sheet 20. Therefore, there is little risk of the heat from the control unit 40 causing variation in growth between the plant PL located close to the control unit 40 and the plant PL located far from the control unit 40. In addition, the substrate 81 and the LED illumination sheet 20 attached to the lower surface side of the substrate 81 constitute a shelf board 83 for the plant cultivation shelf. Alternatively, the substrate 81 and the LED illumination module 10 attached to the lower surface side of the substrate 81 constitute a shelf board 83 for the plant cultivation shelf. In this embodiment, we also provide a shelf board 83 for such a plant growing shelf (Figure 9), a plant growing shelf 80 (Figure 9), and a plant growing factory 90 (Figure 8) equipped with the plant growing shelf 80.

Because the LED lighting sheet 20 according to this embodiment is flexible and lightweight, the LED lighting sheet 20 can be attached to the underside of each substrate 81 more easily than with conventional straight tube lighting devices. Furthermore, because the LED lighting sheet 20 is flexible, the LED lighting sheet 20 can be attached to ceiling surfaces of various sizes and shapes. As a result, the LED lighting sheet 20 according to this embodiment can be applied to various plant cultivation shelves 80 and plant cultivation factories 90.

The LED lighting sheet 20 is also thinner than conventional straight tube lighting devices. This allows the spacing between the substrates 81 in the vertical direction to be narrowed, and the number of substrates 81 included in each plant cultivation shelf 80 to be increased. As a result, the yield of plants PL per unit area can be increased.

As shown in Fig. 10(a)-(b), the LED illumination sheet 20 may be placed not only on the lower surface of the substrate 81, but also on the side of the substrate 81. The LED illumination sheet 20 on the side is suspended from the substrate 81 located above toward the substrate 81 located below the substrate 81. In this case, as shown in Fig. 10(a), the LED illumination sheet 20 may reach the substrate 81 located below. Alternatively, as shown in Fig. 10(b), the LED illumination sheet 20 may cover only the upper side of the space located between the upper and lower substrates 81 without reaching the substrate 81 located below. In this way, by further placing the LED illumination sheet 20 on the side of the substrate 81, the amount of light at the periphery of the substrate 81, where the illuminance is likely to be weak, can be compensated for, and the brightness of the LED illumination sheet 20 can be made uniform within the surface. As a result, the growth of the plant can be made uniform within the surface, and the yield of the plant to be grown can be improved.

As described above, according to this embodiment, the LED illumination sheet 20 is provided with a protective portion 35A that covers the side surface 21b of the LED chip 21 and protects the LED chip 21. This makes it possible to prevent the LED chip 21 from peeling off from the LED illumination sheet 20 even if an operator touches the LED chip 21. This makes it possible to prevent the LED chip 21 from falling onto the plant being grown, and to prevent the phosphor 21d of the LED chip 21 from coming into contact with the plant. This makes it possible to maintain good hygiene of the plant being grown.

According to this embodiment, the protective portion 35A covers the solder portion 36 located on the side of the LED chip 21. This protects the solder portion 36 from moisture that scatters during plant growth, and prevents the solder portion 36 from shorting due to moisture. In addition, since the solder portion 36 is covered by the protective portion 35A, it is possible to prevent the grown plant from coming into contact with the solder portion 36. Furthermore, since the solder portion 36 is covered by the protective portion 35A, it is possible to prevent the solder portion 36 from peeling off from the LED chip 21. In particular, in this embodiment, the portion of the solder portion 36 located on the side of the LED chip 21 is formed in an approximately semicircular shape. This may reduce the bonding strength between the portion of the solder portion 36 located on the side of the LED chip 21 and the side surface 21b of the LED chip 21. In this embodiment, the solder portion 36 is covered with the transparent protective film 35, so that even if the portion of the solder portion 36 located to the side of the LED chip 21 is formed in a substantially semicircular shape, the solder portion 36 can be effectively prevented from peeling off from the LED chip 21. This prevents the solder from coming into contact with the plant. This allows the plant being grown to be kept in good sanitary condition.

In addition, according to this embodiment, the central portion 35a covers the entire surface 21a of the LED chip 21. This can reliably protect the phosphor 21d, which may be disposed at approximately the center of the surface 21a of the LED chip 21, from moisture that scatters during plant growth. In addition, since the central portion 35a covers the entire surface 21a of the LED chip 21, when the LED illumination sheet 20 is used in a plant growth factory, it is possible to prevent the grown plant from coming into contact with the phosphor 21d. Furthermore, since the central portion 35a covers the entire surface 21a of the LED chip 21, it is possible to prevent the phosphor 21d of the LED chip 21 from falling onto the plant being grown, and it is possible to prevent the phosphor 21d from coming into contact with the plant. Therefore, it is possible to maintain the sanitary condition of the plant being grown in good condition.

In addition, according to this embodiment, the thickness of the central portion 35a is formed to gradually increase toward the center of the LED chip 21. This allows the thickness of the portion of the central portion 35a that covers the phosphor 21d that may be placed approximately in the center of the surface 21a of the LED chip 21 to be increased. This makes it possible to more reliably protect the phosphor 21d that may be placed approximately in the center of the surface 21a of the LED chip 21 from moisture that is dispersed during plant growth.

In addition, according to this embodiment, the curved portion 35b of the transparent protective film 35 covers the entire side surface 21b of the LED chip 21. This makes it possible to prevent the LED chip 21 from peeling off from the solder portion 36 even if an operator touches the LED chip 21.

In addition, according to this embodiment, the thickness of the curved portion 35b is formed to gradually increase as it approaches the LED chip 21. This makes it possible to prevent a large localized force from being applied to the joint between the LED chip 21 and the solder portion 36 even if an operator touches the LED chip 21, and more effectively prevents the LED chip 21 from peeling off from the solder portion 36.

In addition, according to this embodiment, the curved portion 35b has a concave shape that is recessed from the light-emitting surface 20a side toward the surface opposite the light-emitting surface 20a in a cross section perpendicular to the light-emitting surface 20a of the LED illumination sheet 20. This effectively prevents the transparent protective film 35 from being damaged due to the force applied to the LED chip 21, even if an operator touches the LED chip 21.

In addition, according to this embodiment, the curved portion 35b covers the solder portion 36 located on the side of the LED chip 21. This makes it possible to protect the solder portion 36 from moisture that scatters when the plant is being grown. Also, because the solder portion 36 is covered by the curved portion 35b, it is possible to prevent the grown plant from coming into contact with the solder portion 36. Furthermore, because the solder portion 36 is covered by the curved portion 35b, it is possible to prevent the solder portion 36 from peeling off from the LED chip 21. This makes it possible to prevent the solder from coming into contact with the plant, and to maintain good hygiene of the plant being grown.

According to this embodiment, in a cross section perpendicular to the light-emitting surface 20a of the LED illumination sheet 20, the thickest part A of the solder part 36 does not contact the side surface 21b of the LED chip 21. This allows the transparent protective film 35 to be interposed between the side surface 21b of the LED chip 21 and the solder part 36, improving the adhesion between the transparent protective film 35 and the LED chip 21. As a result, the transparent protective film 35 can effectively protect the LED chip 21. In addition, by interposing the transparent protective film 35 between the side surface 21b of the LED chip 21 and the solder part 36, even if a worker touches the LED chip 21, the transparent protective film 35 can absorb the force applied to the LED chip 21, and the LED chip 21 can be effectively prevented from peeling off from the LED illumination sheet 20.

In addition, according to this embodiment, when viewed from the light-emitting surface 20a side, the portion of the solder section 36 located to the side of the LED chip 21 is formed so as to surround a part of the side surface 21b of the LED chip 21. This improves the bonding strength between the LED chip 21 and the solder section 36. This makes it possible to prevent the LED chip 21 from peeling off from the solder section 36.

Furthermore, according to this embodiment, the transparent protective film 35 covers the light-reflective insulating protective film 34. This allows the transparent protective film 35 to protect the light-reflective insulating protective film 34.

In addition, according to this embodiment, the protective portion 35A covers the entire surface 21a and side surface 21b of the LED chip 21. This ensures that the LED chip 21 is protected from moisture that may scatter during plant cultivation. Furthermore, by covering the entire surface 21a of the LED chip 21 with the protective portion 35A, the sanitary condition of the plant being cultivated can be maintained in even better condition.

In addition, according to this embodiment, 10 or more LED chips 21 are arranged in series, and the LED chips 21 are arranged in four or more rows in parallel. This allows the LED chips 21 to be arranged uniformly within the surface, and the LED chips 21 to be arranged in parallel, dispersing the risk of damage to the LED chips 21.

In addition, according to this embodiment, the thickness of the LED illumination sheet 20 at its thickest point is 5 mm or less, so by reducing the distance between the upper and lower substrates 81 of the plant growing shelf 80 and increasing the number of substrates 81, the plant yield per unit area can be increased.

In addition, according to this embodiment, the control unit 40 is externally connected to the LED illumination sheet 20, so the control unit 40 can be separated from the LED illumination sheet 20 to prevent the heat from the control unit 40 from affecting the plants.

In addition, according to this embodiment, a constant voltage is applied from the control unit 40 to the LED illumination sheet 20, which increases the integrated amount of light per unit time from the LED chips 21 and promotes plant growth.

In addition, according to this embodiment, the control unit 40 is capable of controlling the dimming of the LED chip 21, so that the intensity of the light from the LED chip 21 can be adjusted according to the growth stage of the plant.

In the above description, an example has been described in which the transparent protective film 35 of the protective portion 35A covers the entire surface 21a and side surface 21b of the LED chip 21, but this is not limited thereto. For example, as shown in FIG. 11, the vicinity of the corner 21e of the LED chip 21 may be exposed. In this case, the amount of resin used to form the transparent protective film 35 can be reduced. Even in this case, the above-mentioned effects can be obtained.

In the above-described embodiment, the transparent protective film 35 is formed by spray coating or curtain coating, but the present invention is not limited to this. For example, the transparent protective film 35 may be formed by attaching a resin film to the LED chip 21 or the light-reflective insulating protective film 34. In this case, the material of the resin film may be a vinyl chloride-based or fluorine-based resin, or a general resin such as polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polyethylene naphthalate (PEN), or polyimide (PI). In this way, even when the transparent protective film 35 is made of a resin film, the above-described effect can be obtained. As shown in FIG. 12, the resin film may be bonded to the light-reflective insulating protective film 34 via, for example, an adhesive 38. The resin film may be bonded to the light-reflective insulating protective film 34 via, for example, an adhesive. Although not shown, the resin film may be bonded to the light-reflective insulating protective film 34 by, for example, heat sealing.

In this case, as shown in FIG. 12, a gap G may be formed between the side surface 21b of the LED chip 21 and the transparent protective film 35. When a gap G is formed between the side surface 21b of the LED chip 21 and the transparent protective film 35, even if an operator touches the LED chip 21, the transparent protective film 35 can be prevented from being damaged due to the force applied to the LED chip 21. In addition, as shown in FIG. 13, a gap may not be formed between the side surface 21b of the LED chip 21 and the transparent protective film 35. When a gap is not formed between the side surface 21b of the LED chip 21 and the transparent protective film 35, the adhesion between the LED chip 21 and the transparent protective film 35 can be improved, and the LED chip 21 and the solder part 36 can be protected more effectively. In this case, the transparent protective film 35 may be bonded to the LED chip 21 and the light-reflective insulating protective film 34 by, for example, a vacuum lamination method.

In the above-described embodiment, the protective portion 35A has only the transparent protective film 35, but the present invention is not limited to this. For example, as shown in Fig. 14, the protective portion 35A may further have an adhesive layer (adhesive layer) 39 that bonds the LED chip 21 and the transparent protective film 35. In this case, it is preferable that the adhesive layer 39 has an insulating property.
This makes it possible to suppress a problem in which the adhesive layer 39 and the LED chip 21 are short-circuited, causing the phosphor 21d of the LED chip 21 to fail to emit light. In the modification shown in Fig. 14, the transparent protective film 35 is adhered to the LED chip 21 via the adhesive layer 39. Even in this case, the above-mentioned effects can be obtained.

In this case, as shown in FIG. 14, no gap may be formed between the side surface 21b of the LED chip 21 and the adhesive layer 39 of the protective section 35A. When no gap is formed between the side surface 21b of the LED chip 21 and the adhesive layer 39, as in the example shown in FIG. 13, the adhesion between the LED chip 21 and the transparent protective film 35 can be improved, and the LED chip 21 and the solder part 36 can be protected more effectively. Also, as shown in FIG. 15, a gap G may be formed between the side surface 21b of the LED chip 21 and the adhesive layer 39 of the protective section 35A. When a gap G is formed between the side surface 21b of the LED chip 21 and the adhesive layer 39, as in the example shown in FIG. 12, even if a worker touches the LED chip 21, the transparent protective film 35 can be prevented from being damaged due to the force applied to the LED chip 21.

Furthermore, as shown in FIG. 16, the adhesive layer 39 may cover the side surface 21b of the LED chip 21. In this case, as shown in FIG. 16, the surface 21a of the LED chip 21 and the surface 39a of the adhesive layer 39 may be flush with each other, or, although not shown, the adhesive layer 39 may be interposed between the surface 21a of the LED chip 21 and the transparent protective film 35. In these cases, the entire surface (light-emitting surface 20a) of the LED illumination sheet 20 becomes smooth. This can improve the cushioning properties of the LED illumination sheet 20 against external impacts. The above-mentioned effects can also be obtained in these cases.

In the above-described embodiment, the protective portion 35A covers the surface 21a of the LED chip 21, but the present invention is not limited to this. For example, as shown in FIG. 17, the protective portion 35A may not cover the surface 21a of the LED chip 21. In this case, the protective portion 35A may not cover a part of the light-reflective insulating protective film 34. That is, the transparent protective film 35 of the protective portion 35A may not include the central portion 35a and the flat portion 35c. The curved portion 35b of the transparent protective film 35 may be configured to cover at least the solder portion 36 located on the side of the LED chip 21 without covering the entire side surface 21b of the LED chip 21. Even in this case, the curved portion 35b of the transparent protective film 35 covers the solder portion 36 located on the side of the LED chip 21, and thus the above-described effect can be obtained.

The multiple components disclosed in the above embodiment and modified examples may be combined as necessary. Alternatively, some components may be deleted from all the components shown in the above embodiment and modified examples.

REFERENCE SIGNS LIST 10 LED lighting module 20 LED lighting sheet 20a Light emitting surface 21 LED chip 21a Surface 21b Side 21c Back surface 21d Phosphor 21e Corner 22 Metal wiring section 30 Flexible wiring board 31 Board film 32 Metal wiring section 33 Adhesive layer 34 Light reflective insulating protective film 35 Transparent protective film 35a Central section 35b Curved section 35c Flat section 38 Adhesive 39 Adhesive layer 36 Solder section 40 Control section 41 Power input section 42 AC/DC converter 43 PWM control section 44A First connector 44B Second connector 45 Regulator 46 Power supply line 80 Animal/plant cultivation shelf 81 Board 82 Support 83 Shelf for animal/plant cultivation shelf 90 Animal/plant cultivation factory 91 building

Claims (19)

An LED lighting sheet for growing plants and animals,
A substrate film;
A metal wiring portion formed on a surface of the substrate film;
an LED chip mounted on the metal wiring portion via a solder portion ;
a light-reflective insulating protective film disposed so as to cover the metal wiring portion;
a protective portion that covers the light-reflective insulating protective film and at least a portion of a side surface of the LED chip to protect the LED chip,
The protective portion has a transparent protective film,
The transparent protective film is
a central portion covering at least a portion of a surface of the LED chip;
a curved portion covering at least a portion of the side surface of the LED chip;
a flat portion formed adjacent to the curved portion;
the transparent protective film is formed from a resin composition,
the light-reflective insulating protective film contains a white pigment and has an average light reflectance of 65% or more in the wavelength range of 400 nm or more and 780 nm or less;
In a cross section perpendicular to the light-emitting surface of the LED illumination sheet for growing animals and plants, the thickest part of the solder portion is not in contact with the side surface of the LED chip,
An LED illumination sheet for growing animals and plants, wherein the protective portion is interposed between the thickest portion of the solder portion and the side surface of the LED chip . The LED illumination sheet for growing animals and plants according to claim 1, wherein the thickness of the central portion gradually increases toward the center of the LED chip. The LED illumination sheet for growing animals and plants according to claim 1 or 2, wherein the protective portion has the transparent protective film containing an acrylic polyurethane resin. 4. The LED illumination sheet for growing animals and plants according to claim 1, wherein the protective portion further comprises an adhesive layer that bonds the LED chips and the transparent protective film. The LED illumination sheet for growing animals and plants according to claim 4 , wherein the protective portion covers a side surface of the LED chip with the adhesive layer. The LED illumination sheet for growing animals and plants according to claim 1 , wherein the central portion covers the entire surface of the LED chip. The LED illumination sheet for growing animals and plants according to claim 1 , wherein the curved portion covers the entire side surface of the LED chip. 8. The LED illumination sheet for growing animals and plants according to claim 1 , wherein the curved portion covers the solder portion located on a side of the LED chip. 9. The LED illumination sheet for cultivating animals and plants as described in claim 8, wherein in a cross section perpendicular to the light-emitting surface of the LED illumination sheet for cultivating animals and plants, a portion of the solder portion located on the side of the LED chip has a curved shape that rises toward the light-emitting surface side. 10. The LED illumination sheet for cultivating animals and plants as described in claim 8 or 9, wherein, when viewed from the light - emitting surface side of the LED illumination sheet for cultivating animals and plants, a portion of the solder portion located on the side of the LED chip is formed so as to surround a portion of the side surface of the LED chip. The LED illumination sheet for growing animals and plants according to claim 1 , wherein the protective portion covers the entire surface and side surfaces of the LED chip. 12. The LED illumination sheet for growing animals and plants according to claim 1, wherein ten or more of the LED chips are arranged in series, and four or more rows of the LED chips are arranged in parallel. An LED lighting module for growing plants and animals,
An LED illumination sheet for growing animals and plants according to any one of claims 1 to 12 ;
a control unit electrically connected to the LED illumination sheet for growing animals and plants,
The control unit is an LED lighting module for cultivating animals and plants that is externally connected to the LED lighting sheet for cultivating animals and plants. The LED lighting module for growing animals and plants according to claim 13 , wherein a constant voltage is applied from the control unit to the LED lighting sheet for growing animals and plants. 15. The LED lighting module for growing animals and plants according to claim 13 , wherein the control unit is capable of controlling dimming of the LED chips. A shelf board for growing plants and animals,
A substrate;
A shelf board for cultivating animals and plants, comprising an LED lighting sheet for cultivating animals and plants described in any one of claims 1 to 12 or an LED lighting module for cultivating animals and plants described in any one of claims 13 to 15 attached to the substrate. A plant and animal growing shelf,
Equipped with shelves,
An animal or plant cultivation shelf comprising an LED lighting sheet for cultivating animals and plants as described in any one of claims 1 to 12 or an LED lighting module for cultivating animals and plants as described in any one of claims 13 to 15 attached to the underside of a substrate. The shelf for cultivating animals and plants according to claim 17 , wherein the LED illumination sheet for cultivating animals and plants is further arranged on a side surface of the shelf board. Buildings and
An animal or plant growing factory comprising: a growing shelf for growing animals or plants according to claim 17 or 18 , arranged inside the building.

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