JP2012003907A - Linear lighting fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear lighting fixture which can restraining deterioration of light-emitting efficiency and short lifetime of an LED by restraining temperature rise of a base board arranged with LEDs while restraining increase of weight of the lighting fixture in the long and narrow linear lighting fixture such as a fluorescent lamp.SOLUTION: In the linear lighting fixture made of the long and narrow base board arranged along the longitudinal direction of the plurality of LEDs and a long and narrow body part for supporting both side ends of the base board in the longitudinal direction, the linear lighting fixture has a heat-transmitting layer including a long and narrow graphite sheet in the longitudinal direction of the base board on a surface opposite to the LED of the base board or inside the base board.

Description

  The present invention relates to a line illuminator, and more particularly to a line illuminator using a light emitting diode (hereinafter referred to as LED).

In an illuminator using an LED, sufficient heat dissipation is required in order to prevent a decrease in luminous efficiency and a shortened life of the LED. From such a viewpoint, in an illuminator using an LED, a substrate on which the LED is mounted is made of an aluminum plate having a high thermal conductivity as a core material.
However, the aluminum substrate has problems such as low processability and high price. In addition, fins may be provided on the substrate to improve heat dissipation, but if fins are provided on the aluminum substrate, the weight of the luminaire increases. For example, when it is placed on the ceiling, a safety problem may occur. is there. For example, current fluorescent lamps are provided with a total weight restriction (500 g or less).
For this reason, an attempt has been made to use a glass epoxy substrate that can replace the aluminum substrate. A general glass epoxy board is widely used as a general electronic circuit board such as a printed circuit board. However, the glass epoxy board has a low thermal conductivity of about 0.3 W / mK and has a heat dissipation property. Since it is very low, the temperature of the LED will rise. Thus, although a glass epoxy substrate with improved heat dissipation has been developed, its thermal conductivity is about 1 W / mK, and it is difficult to say that sufficient thermal conductivity and heat dissipation are realized.

As an improvement measure, a light bulb shaped LED lamp (Patent Document 1) or a linear light source device (Patent Document 2) in which a thermally conductive graphite is provided on a substrate on which an LED is mounted, or a graphite on the back of the bottom of a case where an LED mounting substrate is fixed. A surface illumination device provided with a layer (Patent Document 3) has been proposed. A graphite film with improved thermal conductivity has also been proposed (Patent Document 4).
However, the LED lamp of Patent Document 1 has a light bulb shape, and has a substrate structure that is different from an elongated line illuminator such as a fluorescent lamp, for example. However, the heat conductivity and heat dissipation in the substrate are not actually a problem. The linear light source device described in Patent Document 2 is disposed on one side surface of a light guide plate of a backlight, and a graphite sheet is provided between a linear light source unit in which LEDs are mounted on a substrate and a holding frame. It has been. However, in the linear light source device, the plurality of linear light source units and the graphite sheet are only provided intermittently over the entire length in the longitudinal direction of the holding frame, and the thermal conductivity and heat dissipation in the longitudinal direction are Not necessarily enough. In the surface illumination device described in Patent Document 3, a graphite layer is provided not on the LED mounting substrate but on the lower back surface of the case to which the substrate is fixed, and thermal conductivity and heat dissipation are not necessarily sufficient. . Moreover, the illuminating devices described in Patent Documents 2 and 3 are not supposed to be an elongated line-shaped illuminator such as a fluorescent lamp. Furthermore, when the illumination device described in Patent Documents 2 and 3 is used as a backlight for a liquid crystal display device or the like, the LED mounting substrate is generally a metal having good thermal conductivity because there is no weight restriction such as a fluorescent lamp. It is also possible to fix to the frame. On the other hand, in the case of a line illuminator using LEDs, which is expected as an alternative illuminator for fluorescent lamps in the future, it is essential to reduce the weight because of its nature. It is assumed that it is difficult to use a good metal frame, and more efficient heat dissipation measures are required.

JP 2003-100110 A JP 2007-335371 A JP 2008-108552 A JP 2006-327907 A

  In view of the above problems, an object of the present invention is to reduce the temperature of a substrate on which LEDs are arranged while suppressing an increase in the weight of the illuminator in an elongated line illuminator such as a fluorescent lamp. An object of the present invention is to provide a line-shaped illuminator that can suppress the decrease in the luminous efficiency and the shortening of the lifetime of the LED.

  As a result of intensive studies, the inventors of the present invention have found that the surface of the elongated substrate in which the LEDs are arranged along the longitudinal direction is opposite to the LED, etc., from the same elongated elongated graphite sheet in the longitudinal direction of the substrate. It has been found that the above problem can be solved by providing the heat transfer layer, and the present invention has been completed. That is, the gist of the present invention is as follows.

(1) an elongated substrate in which a plurality of LEDs are arranged along the longitudinal direction;
A line-shaped illuminating device comprising a main body having an elongated shape that supports both side ends of the substrate in the longitudinal direction,
A line-shaped illuminating device, wherein a heat transfer layer including a graphite sheet having an elongated shape extending in the longitudinal direction of the substrate is provided on the surface of the substrate opposite to the LED or inside the substrate.

  (2) The line illuminator according to (1), wherein a heat radiation layer made of a heat radiation member is provided on the outer surface of the heat transfer layer provided on the substrate surface.

  (3) The linear lighting device according to (2), wherein a side end portion of the heat dissipation layer is bent so as to cover a side end portion facing the heat transfer layer.

  (4) The line-shaped lighting device according to (2) or (3), wherein the heat dissipation member is made of a polyethylene terephthalate sheet, a polyethylene sheet, a polypropylene sheet, an acrylic polymer sheet, a silicone polymer sheet, or an aluminum plate.

  (5) The linear illumination tool according to any one of (2) to (4), wherein the emissivity of the heat dissipation member is 0.9 or more.

  (6) The line-shaped lighting device according to any one of (1) to (5), wherein the heat transfer layer is provided with an adhesive layer on the inner surface side that is the substrate side.

  (7) The linear lighting device according to (6), wherein a side end portion of the adhesive material layer is bent so as to cover a side end portion facing the graphite sheet.

  (8) The line-shaped lighting device according to any one of (2) to (6), wherein the heat transfer layer is provided with an adhesive layer on an outer surface side that is the heat radiation layer side.

(9) The substrate is composed of a substrate body and an insulating layer on the side holding the LED,
The line illuminator according to (1), wherein the heat transfer layer is interposed between a substrate body and an insulating layer of the substrate.

  (10) The line illuminator according to (9), wherein the heat transfer layer is provided with an adhesive material layer on a surface side which is the substrate body side.

  (11) The line-shaped lighting device according to (1), wherein a heat transfer layer including an elongated graphite sheet extending in the longitudinal direction of the substrate is also provided on the LED side surface of the substrate.

  (12) The linear illumination device according to any one of (1) to (11), wherein a ratio (length / short) of a length in a longitudinal direction and a length in a lateral direction of the substrate is 10 or more.

  (13) The line-shaped lighting device according to any one of (12), wherein a length of the substrate in a short direction is 30 mm or less.

  (14) The line illuminator according to any one of (1) to (13), wherein an area ratio of the substrate to the heat transfer layer (heat transfer layer / substrate) is 0.9 or less.

  (15) The line-shaped lighting device according to any one of (1) to (14), wherein both end portions of the heat transfer layer are further extended from the substrate-side end portion to the main body portion inner surface side.

  (16) The line illuminator according to any one of (1) to (15), wherein a small hole is provided between the substrate and the heat transfer layer.

  (17) The line illuminator according to any one of (1) to (8) and (11) to (16), wherein the heat transfer layer is bent in a fin shape with respect to the substrate.

  (18) The heat transfer layer is formed in a cylindrical shape by bonding both end portions thereof, and a part or the whole of the outer surface is in close contact with the surface of the substrate opposite to the LED and the inner surface of the main body. (1) to (8) and (11) to (16).

  (19) The line illuminator according to any one of (1) to (18), wherein the graphite sheet has a thermal conductivity of 1000 W / mK or more, a thickness of 10 to 50 μm, and an MIT bending life of 10,000 times or more.

  (20) The linear illumination tool according to any one of (1) to (19), wherein the substrate has a thermal conductivity of 120 W / mK or less and a thickness of 1.5 mm or less.

  (21) The line-shaped lighting device according to any one of (1) to (20), wherein the main body portion is made of a translucent tube.

  (22) The line illuminator according to (21), wherein the translucent tube is formed of one or more selected from polycarbonate resin, acrylic resin, polyethylene terephthalate resin, olefin resin, and silicone resin.

  (23) The line illuminator according to any one of (1) to (22), wherein the weight of the substrate and the graphite sheet is 80 g or less.

  The line illuminating device according to the present invention as described above suppresses an increase in the weight of the illuminating device, suppresses a temperature rise of the substrate on which the LEDs are arranged, and suppresses a decrease in light emission efficiency and a shortened life of the LED. It is a line illuminator that can.

It is a notch perspective view which shows the outline of one Embodiment of the linear illuminating device of this invention. It is sectional drawing in other embodiment of the linear illuminating device of this invention. It is sectional drawing in other embodiment of the linear illuminating device of this invention. It is sectional drawing in other embodiment of the linear illuminating device of this invention. The perspective view which shows typically other embodiment in the structure of a thermal radiation layer and a heat-transfer layer. (A)-(d) is sectional drawing which shows other embodiment of the linear illuminating device which changed the structure of the heat-transfer layer and the heat radiating layer, respectively, based on the embodiment shown in FIG. ) Is a schematic diagram enlarging the components of the heat transfer layer and the heat dissipation layer of (d). It is sectional drawing in other embodiment of the linear illuminating device of this invention. It is sectional drawing which shows typically one Embodiment of the container used when manufacturing the graphite sheet used in this invention. It is the perspective view which showed the outline of the external appearance form of the line-shaped lighting fixture employ | adopted in the simulation of the Example. It is the top view which showed the outline of the board | substrate of the line-shaped lighting fixture employ | adopted in the simulation of the Example. It is sectional drawing which showed typically the outline of the linear illuminating device employ | adopted in the simulation of an Example. It is sectional drawing which showed the outline of the form of the linear illuminating device in a comparative example typically.

  The line-shaped illuminating device according to the present invention is a line composed of an elongated substrate in which a plurality of LEDs are arranged along the longitudinal direction, and a similarly elongated body that supports both end portions of the substrate in the longitudinal direction. In the shape lighting device, a heat transfer layer made of a graphite sheet having the same elongated shape extending in the longitudinal direction of the substrate is provided on the surface of the substrate opposite to the LED or inside the substrate.

  In the present invention, as described above, the heat transfer layer is provided on the surface of the substrate opposite to the LED or inside the substrate. First, a configuration in which a heat transfer layer is provided on the surface of the substrate opposite to the LED will be described as a first mode.

  In the present invention, a plurality of LEDs are arranged on an elongated substrate along the longitudinal direction. As long as the plurality of LEDs are arranged along the longitudinal direction of the substrate, the arrangement method is not particularly limited, and the LEDs may be arranged in one row in the longitudinal direction, or may be arranged in a plurality of rows. . Further, when arranging in a plurality of rows, each row may be arranged in the same phase, may be arranged in a staggered manner, or may be appropriately combined. Further, one or more substrates may be used. Moreover, the said LED can use a well-known thing suitably. Furthermore, the LED may be covered with a silicone resin or the like as long as it does not hinder illumination for the purpose of protection or heat dissipation.

  The substrate has an elongated shape in which a plurality of LEDs can be arranged along the longitudinal direction. The elongated shape is not particularly limited, but the ratio of the length in the longitudinal direction to the length in the short direction of the substrate (long / short) is preferably 10 or more. The length of the substrate in the short direction is preferably 30 mm or less. Examples of such an elongated shape include the ratio of the length in the longitudinal direction to the short direction of fluorescent lamps that are currently generally used. Further, the substrate may be a flat plate over the entire length, or the surface on which the LEDs are arranged may be a convex surface. Further, the number of substrates may be one or plural.

  In addition, the substrate preferably has a thermal conductivity of 120 W / mK or less and a thickness of 1.5 mm or less. With such characteristics, heat generated in the LED tends to be diffused to the heat transfer layer, and the temperature rise of the LED tends to be easily suppressed. Moreover, the structure of the said board | substrate does not have limitation in particular, Well-known things, such as what was comprised with resin, the thing comprised with the metal, the thing which provided the insulating layer on the metal surface, can be utilized.

  The main body supports both side ends of the substrate in the longitudinal direction, and has an elongated shape similar to the substrate. The structure for supporting the substrate is not particularly limited, and a known structure may be adopted in consideration of the material of the main body and the substrate.

  The shape of the main body is not particularly limited as long as it is an elongated shape capable of accommodating the substrate therein, and the overall appearance can be various shapes such as a columnar shape and a prismatic shape. For example, as shown in FIG. 1, as the main body portion 4, a support portion 5 that supports the substrate 3 and the like from the side where the LEDs are not disposed, a cover 6 that covers the substrate 3 and the like from the side where the LEDs are disposed, and a support portion 5 You may comprise from the cap 7 provided with the connection pin 12 which is distribute | arranged to the both ends of the cover 6 and bears connection with an external power supply, and a cylindrical molded object (translucent property) by uniting a support part and a cover. Tube). When the main body is the former, it is preferable to use a metal (for example, aluminum) having good thermal conductivity for the support 5 and a translucent resin for the cover 6. The said resin can use the thing similar to the translucent tube mentioned later. When the main body is the latter, that is, a translucent tube in which the support portion and the cover are integrated, the translucent tube is selected from polycarbonate resin, acrylic resin, polyethylene terephthalate resin, olefin resin, and silicone resin. It can form by 1 type (s) or 2 or more types. Examples of the olefin resin include cyclic polyolefins in addition to linear polyolefins such as polyethylene and polypropylene. For the tube, it is preferable to select a resin having good emissivity. It can shape | mold by well-known methods, such as extrusion molding and injection molding.

  In the first form, the heat transfer layer is provided on the surface of the substrate opposite to the LED, and includes an elongated graphite sheet extending in the longitudinal direction of the substrate. In this way, the heat transfer layer is arranged in the longitudinal direction of the elongated substrate in the same manner, and the both ends from the central portion in the longitudinal direction of the substrate that becomes relatively high temperature due to the light emission of the LED. Heat can be easily diffused to improve heat dissipation and suppress an increase in LED temperature. On the other hand, when the graphite sheet is intermittently arranged in the longitudinal direction (using a plurality of graphite sheets having a short length in the longitudinal direction), the thermal conductivity is remarkably lowered at the joint portion of the graphite sheet, Heat dissipation is reduced.

  The shape of the graphite sheet constituting the heat transfer layer is not particularly limited as long as it is capable of diffusing heat generated in the LED and has an elongated shape extending in the longitudinal direction of the substrate. For example, the shape may be arranged on the entire surface of the substrate opposite to the LED, the shape may be arranged smaller than the surface, or the shape may be arranged larger.

When the heat transfer layer is arranged smaller than the surface of the substrate opposite to the LED, the area ratio of the substrate to the heat transfer layer (heat transfer layer / substrate) is preferably 0.9 or less. With such an area ratio, if the load when the substrate and the heat transfer layer are pressure-bonded is the same, if the area ratio decreases, the pressure applied to the heat transfer layer per unit area increases, and the substrate surface The heat transfer layer enters the slight unevenness, and the adhesion can be improved. As a result, the thermal conductivity from the substrate to the heat transfer layer is improved, and the temperature rise of the LED can be suppressed.
Moreover, when arranging a heat-transfer layer larger than the surface on the opposite side to LED of a board | substrate, the shape of a heat-transfer layer can employ | adopt various shapes like (i)-(iv) mentioned later, for example. it can.

  In this embodiment, a heat transfer layer made of an elongated graphite sheet extending in the longitudinal direction of the substrate may also be provided on the LED side surface of the substrate. In this case, it goes without saying that a graphite sheet is not disposed in the LED portion so as not to prevent the irradiation of light from the LED. This configuration can also be adopted in the second embodiment.

  The characteristics of the graphite sheet are not particularly limited, but it is preferable that the thermal conductivity is 1000 W / mK or more from the viewpoint of efficient thermal diffusion. The thermal conductivity can be measured as described later.

  Moreover, as for the thickness of a graphite sheet, 10-50 micrometers is preferable. If thickness is 10 micrometers or more, the heat | fever which generate | occur | produces from LED can fully be spread | diffused and the temperature reduction effect can be acquired. In addition, when providing a heat radiating member such as an aluminum plate or a heat sink on the substrate, if a graphite sheet is provided between the substrate and the heat radiating material, the graphite sheet exhibits the effect of a buffer material if the thickness is 10 μm or more, and contact resistance Therefore, a temperature reduction effect can be obtained. If it is 50 micrometers or less, a weight increase can be suppressed also when a graphite sheet is provided. The thickness can be calculated as described below.

  Moreover, it is preferable that the MIT bending life of a graphite sheet is 10,000 times or more. If the MIT bending life is 10000 times or more, for example, a member in which a heat-dissipating layer, a graphite sheet, and an adhesive material layer, which will be described later, are sequentially laminated is formed, and when the member is attached to the substrate, the graphite sheet is broken or torn. It can be bonded onto the substrate without causing it. Moreover, even if it peels off from a board | substrate once by mistake in sticking etc. and it sticks together again, it can peel without damaging a graphite sheet, and it can bond again. The MIT bending life can be measured as described below.

An elongated graphite sheet having such characteristics can be produced by the following method.
For example, a container 38 including an inner cylinder 35, an outer cylinder 36, and lids 37 arranged at both ends of the outer cylinder as shown in FIG. 8 is prepared. The hole 39 provided in the lid 37 is provided for discharging the decomposition gas generated during carbonization out of the system of the container 38. The container is made of a material that can withstand continuous use at a high temperature as described below, and examples thereof include graphite and ceramic. The size of the container can be appropriately determined in consideration of the size of the obtained graphite sheet. Then, a film-like sheet made of a polymer compound having an elongated shape (for example, a width of 100 to 500 mm and a length of 35 m) is wound around the inner cylinder 35. As the polymer compound constituting the sheet, for example, those described in Patent Document 4 such as polyimide and polyamide can be used, but polyimide is preferable from the viewpoint of obtaining the above physical properties.

  Next, the inner cylinder 35 around which the sheet is wound is placed in a container 38, and the container 38 is turned sideways in the electric furnace (the state where the lid 37 is arranged on the left and right as shown in FIG. 8, the same applies hereinafter). To place. And it heats up to 1400 degreeC in nitrogen atmosphere, and performs a carbonization process. The heating rate at this time is 1 to 5 ° C./min in order to prevent sheet fusion, cracking, folding, and undulation, and the holding time at 1400 ° C. is preferably about 5 minutes.

  Thereafter, the outer cylinder 36 is removed and placed in the graphitization furnace (the state where the carbonized sheet supported by the lid 37 and the inner cylinder 35 floats in the air) is heated to 2800 ° C. and graphitized. . The temperature increase rate at this time is preferably set to 0.5 to 10 ° C./min in order to prevent unevenness (small protrusions), wrinkles, tears, and sagging. The holding time at 2800 ° C. may be approximately 5 minutes. Then, after cooling to room temperature, the graphite sheet obtained by the graphitization treatment is wound around the inner cylinder 35 so as not to loosen, and is placed sideways in the graphitization furnace in the same manner as in the previous graphitization treatment, The temperature is raised to 2900 ° C. and graphitization is performed. The heating rate is the same as in the previous graphitization treatment.

After cooling to room temperature, the graphite sheet obtained by performing the graphitization treatment twice is compressed at room temperature. The compression process may be performed using a known apparatus that can compress a long graphite sheet. The load at this time may be 40 to 120 kgf / cm ² (3.9 to 11.8 MPa) in the thickness direction.
A graphite sheet having a width of 30 mm or less can be obtained by cutting the graphite sheet obtained as described above.

  The graphite sheet obtained in this way is re-graphitized at a higher temperature than the first time and subjected to compression treatment, so that a graphite sheet having no flatness and high flatness can be obtained. By improving the flatness in this way, generation of wrinkles can be suppressed and the adhesion can be improved when the heat transfer layer including the graphite sheet is bonded to the heat dissipation layer, the adhesive layer, the substrate, and the like. You can also

The flatness can be confirmed by measuring the sag of the graphite sheet obtained by the compression treatment. For example, the outermost portion measured in a 30 mm width sheet (near both sides of the 30 mm width sheet) and the central portion (30 mm). It is preferable that the value A calculated from the following equation as a difference in sag in the width sheet (around 15 mm from both sides) is 8 mm or less.
A = (sag at the end) − (sag at the center)

  The sag of the graphite sheet can be evaluated according to JIS C2151. Specifically, a film (test piece) of a predetermined length is unwound and placed on two parallel bars separated by 1500 mm in a perpendicular direction, and the deviation from a uniform catenary line is measured at the center. Since the graphite sheet is a material that is extremely easy to tear, the tension applied to the sheet is 20 gf (0.20 N) per 10 mm of the sheet width. In addition, a test piece is used which is slowly drawn from a roll of graphite sheet with a minimum tension necessary for unwinding to a new length of about 2000 mm. At this time, the portion from which the test piece is taken out is near the center of the roll winding. For example, in the case of a 40-m roll, three test pieces are taken out from around 20 m from the end of winding. The slack value of the test piece is the median value of three measurements.

  The calculation of A is based on JIS C2151 as described above, and the sag at the end and the sag at the center are measured, and the difference is calculated as A. Specifically, a film (test piece) of a predetermined length is rewound and placed on two parallel bars separated by 1500 mm in a perpendicular direction, and the length of slack from the catenary line at the end is measured. Next, the length of slack from the catenary line at the center is measured, and the A value is calculated. The same measurement was performed on both sides of the sheet, and the average value was taken as one measurement. The value of the sagging at the end is carried out for three test pieces, and the median value thereof is taken.

Further, the thermal conductivity in the plane direction of the graphite sheet can be calculated by multiplying the thermal diffusivity, density, and specific heat in the plane direction as in the following formula.
λ = αdC
λ: thermal conductivity in the plane direction (W / mK)
α: thermal diffusivity in the plane direction (m ² / s)
d: Density (kg / m ³ )
C: Specific heat (J / kg · K)

  The thermal diffusivity in the plane direction was measured by cutting a graphite film into a 4 × 40 mm sample shape using a thermal diffusivity measuring device (“LaserPit” available from ULVAC-RIKO Co., Ltd.) by an optical alternating current method. It can be determined by measuring at 10 Hz in an atmosphere of ° C.

The density can be calculated by dividing the weight (g) of the graphite sheet by the volume (cm ³ ) calculated by the product of the vertical, horizontal and thickness of the graphite sheet.

  The specific heat can be measured from 20 ° C. to 260 ° C. under a temperature rising condition of 10 ° C./min using a differential scanning calorimeter DSC220CU which is a thermal analysis system manufactured by SII Nano Technology Co., Ltd.

  The thickness of the graphite sheet is a 200 mm × 250 mm graphite sheet using a thickness gauge (HEIDENHAIN-CERTO, manufactured by HEIDENHAIN Co., Ltd.), measuring 10 points in a constant temperature room at 25 ° C., and averaging Use the value. As for the thickness variation, about 10 graphite sheets, arbitrary 10 points in the sheet surface are measured and taken as a difference from the average value.

  The MIT bending life (MIT flex resistance test) of the graphite sheet was obtained by cutting the graphite sheet to 1.5 × 10 cm and using a MIT fatigue resistance tester model D manufactured by Toyo Seiki Co., Ltd., with a test load of 100 gf (0 .98 N), the speed is 90 times / minute, and the radius of curvature R of the bending clamp is 2 mm. The bending angle is measured at 135 ° to the left and right. A spring with a diameter of 14 mm is used.

  In a 1st form, you may provide the thermal radiation layer which consists of a thermal radiation member in the outer surface of the heat-transfer layer provided in the said board | substrate surface. In this case, the position of the side end of the heat dissipation layer may be provided so as to coincide with the position of the side end of the corresponding heat transfer layer (for example, the positional relationship between the heat transfer layer and the heat dissipation layer shown in FIGS. 2 to 5). Further, the side end portion of the heat dissipation layer may be bent so as to cover the side end portion facing the heat transfer layer (for example, arrangement of the heat transfer layer and the side end portion of the heat dissipation layer shown in FIG. 6). By providing the heat dissipation layer in this manner, the heat dissipation from the heat transfer layer is improved, and the temperature rise due to the LED can be further suppressed.

  Further, when the side end portion of the heat dissipation layer is provided so as to cover the side end portion facing the heat transfer layer, the heat transfer layer is further provided on the surface opposite to the heat dissipation layer, which will be described later. Is provided (for example, in the case shown in FIG. 6), the graphite sheet is covered with the heat dissipation layer and the adhesive material layer, so that the configuration, that is, the heat dissipation layer, the graphite sheet, and the adhesive material so as to cover the graphite sheet. When a sheet in which the layers are sequentially laminated and integrated is formed as a single member, it is possible to prevent the graphite sheet from falling off. Moreover, when the member is attached to the substrate, it is possible to prevent delamination of the graphite sheet having low interlayer strength when the graphite sheet once accidentally attached to the substrate is peeled off from the substrate. A typical example of such a configuration is the configuration shown in FIG. 6, but the configuration in which the adhesive layer extends along the side edge to the vicinity of the upper surface of the graphite sheet in the figure, and the heat radiation layer is arranged outside thereof, A configuration in which the side edges of the layer and the graphite sheet are made to coincide with each other and the heat dissipation layer is arranged along these side edges can be exemplified.

The heat dissipation member is not particularly limited as long as it can promote heat dissipation from the heat transfer layer, but from the viewpoint of radiation efficiency, that is, heat dissipation, a polyethylene terephthalate sheet (PET sheet), a polyethylene sheet, and polypropylene. It is preferable to use a member made of a sheet, an acrylic polymer sheet, a silicone polymer sheet, or an aluminum plate. Moreover, it is preferable to use the member whose emissivity is 0.9 or more from a viewpoint of ensuring high heat dissipation.
The emissivity can be measured by measuring a heat radiating member having a predetermined size (for example, 100 × 100 mm) at 23 ° C. using an emissivity measuring apparatus manufactured by Japan Sensor Co., Ltd., TSS-5X. The higher the emissivity, the higher the ability to convert and radiate heat from infrared rays to far infrared rays.
Moreover, the thickness of the heat radiating member which comprises a heat radiating layer does not have limitation in particular, What is necessary is just to determine suitably with the heat radiating characteristic of the material to be used.

  In the first embodiment, an adhesive layer may be provided on the inner surface side that is the substrate side in the heat transfer layer. In this case, the pressure-sensitive adhesive layer may be provided so that the position of its side edge coincides with the position of the corresponding side edge of the graphite sheet (for example, the positional relationship between the graphite sheet and the pressure-sensitive adhesive layer shown in FIGS. 2 to 5). ), And may be provided so that the side edge of the adhesive layer covers the side edge of the graphite sheet facing (for example, the arrangement of the graphite sheet and the side edge of the adhesive layer shown in FIG. 6). By providing the adhesive material layer in this manner, the adhesion between the substrate and the heat transfer layer is improved, the thermal conductivity from the substrate to the heat transfer layer is improved, and the temperature rise of the LED can be suppressed. Further, when the adhesive material layer is provided so that the side end portion of the adhesive material layer covers the side end portion facing the graphite sheet, and further provided with a heat dissipation layer, it is described in detail in the description of the heat dissipation layer. The same applies to.

Moreover, when providing a thermal radiation layer in the outer surface of the said heat-transfer layer, you may provide an adhesive material layer in the outer surface side used as the said thermal radiation layer side. By providing the adhesive material layer in this way, the adhesion between the heat dissipation layer and the heat transfer layer is improved, the thermal conductivity from the heat transfer layer to the heat dissipation layer is improved, and the temperature rise of the LED can be suppressed. Become.
The adhesive layer as described above is not particularly limited as long as thermal conductivity is ensured, and a commercially available adhesive material such as a silicone-based adhesive material or an acrylic adhesive material can be used.

  As described above, when the heat transfer layer is arranged larger than the surface of the substrate opposite to the LED, the shape of the heat transfer layer is, for example, the following (i) to (iv) ) Can be employed. Moreover, you may combine these shapes suitably in the possible range.

  (I) Both end portions (side ends in the short direction) of the heat transfer layer are configured to further extend from the substrate side end portion to the inner surface of the main body portion. Thereby, thermal diffusion from the heat transfer layer to the main body portion is achieved, and heat dissipation can be further improved by enabling heat dissipation from the main body portion.

  (Ii) The heat transfer layer is configured to be bent in a fin shape with respect to the substrate. Thereby, the flow of the air inside a main-body part is accelerated | stimulated, and the heat dissipation in the part comprised in the fin shape among heat-transfer layers improves.

  (Iii) A small hole is provided between the substrate and the heat transfer layer. The arrangement of the small holes is not particularly limited as long as air can be effectively flowed. For example, the small holes may be provided over substantially the entire length in the longitudinal direction of the substrate, or may be provided partially. Thus, the heat dissipation of the heat transfer layer is improved by the air flowing through the small hole portion.

(Iv) The heat transfer layer is formed in a cylindrical shape by sticking both end portions thereof, and a part or the whole of the outer surface is in close contact with the surface of the substrate opposite to the LED and the inner surface of the main body. It is configured to be supported by In this way, the heat transfer layer is in intimate contact with the surface of the substrate opposite to the LED and the inner surface of the main body, so that heat transfer to the main body is promoted and the temperature rise of the LED can be effectively suppressed. it can. Moreover, in order to support a heat-transfer layer, you may arrange | position a core material inside a cylinder shape. By arranging the core material, the heat transfer layer can be easily adhered to the inner surface of the main body.
Moreover, when the graphite sheet which comprises a heat-transfer layer is formed in a cylinder shape, it becomes easy to hold | maintain the said shape. For example, a cylindrical sheet can be easily formed by wrapping a graphite sheet around a core material, which is particularly effective when the heat transfer layer is formed in an elongated shape as in the present invention. Although there is no limitation in particular as the said core material, It is preferable to use a foam. By using a foam, flexible shape change is possible, stress can be relieved when pressed between the main body and the substrate, without damaging the graphite sheet constituting the heat transfer layer In addition, the adhesion between the heat transfer layer and the substrate or the main body can be improved. The foam is not particularly limited, and a foamed resin such as a urethane resin or a styrene resin formed by a known method can be used.

  The above configuration will be described in detail with reference to the drawings. FIG. 1 is a cutaway perspective view showing an outline of an embodiment of a line illuminator according to the present invention. A line-shaped luminaire 1 shown in FIG. 1 includes a substrate 3 (consisting of an aluminum substrate (also referred to as an aluminum substrate) 9) and an insulating layer 8 on which a plurality of LEDs 2 are arranged in a row, and a main body 4. The main body 4 includes a support 5 that supports both side ends of the substrate 3 along the longitudinal direction from the side where the LEDs are not disposed, a cover 6 that covers the substrate 3 from the side where the LEDs are disposed, and connection with an external power source. And a cap 7 which is disposed at both ends of the support 5 and the cover 6 in the longitudinal direction and fixes the two. Further, the support portion 5 and the cover 6 are fitted and fixed by a hook 13. Further, a heat transfer layer 10 and a heat dissipation layer 11 are sequentially laminated on the back surface side opposite to the surface on which the LED 2 is disposed of the substrate 3.

  2-4 is a cross-sectional view in the short-side direction of the line illuminator according to the present invention, and the position of the side end of the heat dissipation layer is provided so as to coincide with the position of the side end of the corresponding heat transfer layer. However, the embodiments have different substrates, heat transfer layers, and heat dissipation layers, respectively. In the embodiment shown in FIG. 2 (a), a light-transmitting tube 14 made of polycarbonate is used as a main body, and a substrate in which an insulating layer 8 is arranged on the surface side of the aluminum substrate 9 (below the substrate 9 in the figure). 3 is a line illuminating device in which the LEDs 2 are arranged and the heat transfer layer 10 and the heat dissipation layer 11 are provided on the entire back surface of the substrate 9 (upper side of the substrate in the figure). Moreover, as shown in FIG.2 (b), the thermal radiation layer 11 is provided in the outer surface (upper side of a figure) of the heat-transfer layer 10 in the layer form, for example using the PET sheet | seat. Further, the heat transfer layer 11 is provided with an adhesive material layer 16 and a graphite sheet 15 in a layered order from the inner surface side (lower side in FIG. 2B), which is the substrate side, toward the outer surface.

  The embodiment shown in FIG. 3 is different from the embodiment shown in FIG. 2 in that the LEDs 2 are arranged on the surface side of the glass epoxy substrate 17 (the lower side of the substrate 17 in FIG. 3A). The heat transfer layer 10 and the heat dissipation layer 11 are arranged in layers on the entire back surface of the substrate 17 (upper side of the substrate 17 in FIG. 3A). The configurations of the heat transfer layer 10 and the heat dissipation layer 11 are shown in FIG. This is the same as the embodiment shown (see FIG. 3B).

  In the embodiment shown in FIG. 4, the LEDs 2 are arranged on the front surface side of the glass epoxy substrate 17 (the lower side of the substrate 17 in FIG. 4A), and the back surface of the substrate 17 (the upper side of the substrate 17 in FIG. 4A). 3) The point that the heat transfer layer 18 and the heat dissipation layer 19 are arranged on the whole is the same as the embodiment shown in FIG. 3, but in this embodiment, the heat dissipation member constituting the heat dissipation layer 19 is an aluminum plate. As shown in FIG. 4B, the thermal layer 18 adheres to the inner surface side (lower side of FIG. 4B) which is the substrate side and the outer surface side which is the heat radiation layer side (upper side of FIG. 4B). 3 is different from the embodiment of FIG. 3 in that the material layer 16 is provided.

  FIG. 5 is a perspective view schematically showing another embodiment of the configuration of the heat dissipation layer and the heat transfer layer. The embodiment shown in FIG. 5 is different from the configurations of the heat dissipation layer and the heat transfer layer in the embodiment shown in FIGS. 2 to 4, and the side edges 21 a and 21 b of the heat dissipation layer 20 form the graphite sheet 15 constituting the heat transfer layer. The side end portions 24a, b of the adhesive layer 23 are bent so as to cover the side end portions 22a, b facing the graphite sheet 15. It is provided.

  6 (a) to 6 (d) are cross-sectional views showing other embodiments of the line illuminating device based on the embodiment shown in FIG. 3 and changing the structure of the heat transfer layer and the heat dissipation layer, FIG.6 (e) is the schematic diagram which expanded the structural part of the heat-transfer layer of FIG.6 (d), and a thermal radiation layer.

  6 (a) is an example in which both end portions of the heat transfer layer 10 and the heat dissipation layer 11 are extended from the substrate side end portion 25 to the inner surface side 26 of the translucent tube 14 constituting the main body portion. The installation part 27 is provided, and shows one Embodiment of said (i). The extending portion 27 may be provided over the entire length in the longitudinal direction or may be provided partially.

  In the modified example of FIG. 6B, a small hole 28 is provided between the substrate 17 and the heat transfer layer 10, and shows one embodiment of the above (ii). The small holes 28 may be provided over the entire length in the longitudinal direction or may be provided partially. In this modification, the heat transfer layer and the heat dissipation layer are provided with protrusions. However, the heat transfer layer and the like are formed in a planar shape, and a groove is provided on the substrate 17 side to provide the substrate and the heat transfer layer. A small hole may be formed between the two.

  In the modified example of FIG. 6C, both end portions of the heat transfer layer 10 and the heat dissipation layer 11 are bent to provide fin-like protrusions 29, which shows one embodiment of the above (iii) It is. The protrusion 29 may be provided over the entire length in the longitudinal direction or may be provided partially. Moreover, you may join the edge part of a projection part with the inner surface of the translucent tube 14 which comprises a main-body part.

  In the modified example of FIG. 6D, the heat transfer layer 10 is configured in a cylindrical shape by sticking both side end portions thereof, and a part of the outer surface of the heat transfer layer 10 covers the surface 30 on the opposite side of the LED 2 and the main body portion. This is configured to be supported in close contact with the inner surface 26 of the translucent tube 14 to be configured, and shows one embodiment of the above (iv). In this embodiment, the core material 31 is arrange | positioned over the inside inside a cylindrical shape. FIG.6 (e) is an enlarged view which shows the part comprised by the heat-transfer layer 10, the heat dissipation layer 11, and the core material 31 of FIG.6 (d), from the core material 31 side of FIG.6 (e). A PET sheet that constitutes the heat dissipation layer 11, a graphite sheet 15 that constitutes the heat transfer layer 10, and an adhesive layer 16 are arranged in a radial order.

Next, a second embodiment, which is a configuration in which a heat transfer layer is provided inside the substrate, will be described. Here, only points peculiar to the second embodiment will be described, and description of portions common to the first embodiment will be omitted.
Here, the inside of the substrate means a portion other than the front and back surfaces of the substrate, and the case where the intermediate layer in the case of the substrate having the layer structure is included in the “inside of the substrate” in the present invention. Therefore, when the substrate is composed of the substrate main body and the insulating layer on the side holding the LED, the heat transfer layer may be interposed between the substrate main body and the insulating layer of the substrate. As the heat transfer layer used at this time, the same shape and material as in the first embodiment can be adopted.
In addition, from the viewpoint of improving the adhesion between the substrate body and the heat transfer layer and improving the heat transfer property, the heat transfer layer may be provided with an adhesive layer on the surface side which is the substrate body side. In the second embodiment, since the substrate body plays the role of the heat dissipation layer, no heat dissipation layer is provided.

  A 2nd form is demonstrated in detail using drawing. FIG. 7A is a cross-sectional view in the short-side direction of the line-shaped illuminating device according to the present invention. The transparent tube 14 made of polycarbonate is adopted as the main body, and an aluminum substrate main body (also referred to as an aluminum substrate main body) 32 is used. This is a line illuminating device in which a heat transfer layer 34 is provided on the surface side (the lower side of the substrate body 32 in the figure), and an insulating layer 33 is further provided on the lower side of the heat transfer layer 34 to arrange the LEDs 2. As shown in FIG. 7B, the heat transfer layer 34 in the present embodiment is formed by providing the adhesive sheet 16 on the substrate body 34 side of the graphite sheet 15 and laminating it.

  Since the line illuminator according to the present invention is provided with a heat transfer layer including an elongated graphite sheet, the heat transfer performance is improved without providing the metal fins conventionally provided on the metal substrate. Since the temperature rise of the LED can be suppressed, the weight of the substrate and the graphite sheet constituting the line illuminator can be 80 g or less. Therefore, the present invention is particularly suitable as a line-shaped illuminator that can be used in place of a fluorescent lamp, is light, and can suppress a decrease in LED light emission efficiency and a reduction in lifetime.

Next, the present invention will be described in more detail by way of examples.
(Production example)
First, an example of producing an elongated graphite sheet used in the present invention will be described below.
<Graphite sheet with a thickness of 40 μm>
A polyimide film having a thickness of 75 μm, a width of 250 mm, and a length of 35 m was wound around a graphite inner cylinder 35 having an outer diameter of 100 mm and a length of 300 mm using the container 38 shown in FIG. An outer cylinder 36 having an inner diameter of 130 mm and a lid 37 were covered. The container 38 was set sideways in the electric furnace, and heated to 1400 ° C. at a heating rate of 2 ° C./min in a nitrogen atmosphere to perform carbonization treatment. The holding time at 1400 ° C. was 5 minutes. Next, the obtained roll-shaped carbonized film was set in a graphitization furnace in a horizontal direction (a state in which the carbonized film was suspended in the air by a support), and the temperature was raised to 2800 ° C. at a heating rate of 3 ° C./min. The conversion process was carried out. The holding time at 2800 ° C. was 5 minutes. After cooling, the graphite film obtained by the graphitization treatment is again tightened around the inner cylinder 35 having an outer diameter of 100 mm so as not to be loosened, and the container 38 is set again horizontally in the graphite furnace and again raised to 2900 ° C. The temperature was raised at a temperature rate of 5 ° C./min, and graphitization was performed. The holding time at 2900 ° C. was 5 minutes.
The obtained graphite film was subjected to compression treatment (in the thickness direction, a load of 80 kgf / cm ² (7.8 MPa) was applied and pressed with a press machine) to obtain a graphite sheet having a thickness of 40 μm.

<Graphite sheet with a thickness of 25 μm>
A graphite sheet having a thickness of 25 μm was obtained in the same manner as the graphite sheet having a thickness of 40 μm, except that a polyimide film having a thickness of 50 μm, a width of 250 mm, and a length of 50 m was used (Apical AV manufactured by Kaneka Corporation).

<Measurement of characteristics of graphite sheet>
About each graphite sheet obtained by making it above, the heat conductivity, thickness, and MIT bending life were computed by the method mentioned above. The thickness of each sheet was 25 μm and 40 μm, respectively, the thermal conductivity was 1200 W / mK, and the MIT bending life was 10,000 times or more. Further, the A value as an index of flatness was 8 mm or less for all sheets.

(simulation)
In this invention, the heat dissipation by this invention was verified using the simulation technique which the method has already established. That is, the maximum temperature at the center of the LED surface when the line-shaped illuminator was turned on under a predetermined condition was referred to, and the degree of the temperature was verified. First, simulation conditions will be described. In addition, the temperature of LED is the value which referred LED located in the edge part and center part of the longitudinal direction of a linear illuminating device.

  FIG. 9 shows an outline of the overall structure of the line-shaped illuminator 44 employed in the simulation. As shown in FIG. 9, a rectangular shape was adopted as the overall shape including the translucent tube 40 (made of polycarbonate) and the cap 42 constituting the main body 43. Further, the LED 2 is disposed on the substrate 41 inside the main body 43. In addition, as shown in FIG. 9, the simulation was performed by setting the short direction of the linear illumination tool 44 to x, the longitudinal direction to y, and the height direction to z.

  FIG. 10 shows an outline of the portion of the substrate 41 and the like. The number of LEDs 2 was 100, the size of the LEDs 2 was 2 × 3 × 2 mm, and the heat generation amount was 120 mW / piece. The calorific value was calculated by multiplying the total power consumption by the number of LEDs, assuming that the conversion efficiency to light is 0.3, from the published value of a general LED lamp (17W), and multiplying by 0.7. It is. The length (L) in the longitudinal direction of the line-shaped illuminator 44 was 1178 m, and the length (W) in the lateral direction was 30 mm. Moreover, as shown to Fig.11 (a), the height (H) of the main-body part 43 was 30 mm. The substrate 41, the translucent tube 40 constituting the main body 43, and the cap 7 were all 1 mm in thickness. Table 1 summarizes various conditions such as the software used.

(Examples 1-12, Comparative Examples 1-4)
The configurations of the substrate, the main body, the heat transfer layer, and the heat dissipation layer were set as shown in Tables 3 to 5, and simulations were performed using the material property values shown in Table 2. The heat transfer layer was provided over the entire length in the longitudinal direction of the substrate. In Table 2, LED (silicone resin) indicates physical properties of a member composed of an LED and a silicone resin covering the LED.

  The structures of the substrate, the heat transfer layer, and the heat dissipation layer correspond to FIGS. 2 to 4, 7, 6 (a) and 6 (d) (Example) and FIGS. 12 (a) to (c) (Comparative Example). The thing was adopted. In addition, Example 11 and 12 is a structure corresponding to FIG.6 (d) and (a), respectively. Example 9 is based on the configuration of the substrate 3, the heat radiation layer 11, and the heat transfer layer 10 shown in FIG. 2, and the configuration is provided with a cylindrical layer shown in FIG. 6 (d). . In Example 10, the configuration of the substrate 3, the heat radiation layer 11, and the heat transfer layer 10 shown in FIG. 2 is used as a base, and the shape thereof is shown in FIG. These configurations are shown as FIG. 6A 'and FIG. 6D' as a configuration example in Table 3 for convenience.

  In Examples 9 to 12, the shape other than the laminated structure of the heat transfer layer and the heat dissipation layer is an extension portion of the layer 45 composed of the heat transfer layer and the heat dissipation layer shown in FIGS. 11B and 11C. The simulation was performed by adopting a shape based on a straight line instead of a curve, such as the cross-sectional shape of the cylindrical layer 45 having the core material 47 in the inner cavity portion. In FIG.11 (b), the length (h1) of the extension part 46 was 5 mm. In FIG. 11C, the height (h2) of the cylindrical layer 45 having the core material 47 in the inner cavity is 13 mm, and the width (w1) in close contact with the substrate 41 and the inner surface of the translucent tube 40 is set. 7 mm.

  FIG. 12A shows a mode in which the heat transfer layer 10 and the heat dissipation layer 11 are removed from the configuration of FIG. FIG. 12B shows a mode in which the heat transfer layer 10 and the heat dissipation layer 11 are removed from the configuration of FIG. FIG. 12C shows a mode in which the heat transfer layer 18 is removed from the configuration of FIG. FIG. 12D shows a mode in which the heat transfer layer 34 is removed from the configuration of FIG. 12A and 12D have substantially the same configuration in that an insulating layer is provided on the aluminum substrate or the aluminum substrate body.

  The structure of an Example and a comparative example and the evaluation result based on a simulation result are shown to Tables 3-5. As evaluation about the temperature of Tables 3-5, the value of the center part of the comparative example in a table | surface is made into a reference value, respectively, and the temperature of the reference | standard "center part" is subtracted from the temperature of "center part" of each Example. The value was shown. The column of the effect of the comparative example as a reference is 0. Moreover, as evaluation regarding a weight, A was 75 g or less, B was 75.1-100 g, C was 100.1-160 g, D was 160.1 g or more. GS is an abbreviation for graphite sheet.

Compared to the case where a glass epoxy substrate is used as the substrate (Comparative Example 2) and the case where an aluminum substrate having a high thermal conductivity of 120 W / mK is used (Comparative Example 1), the weight can be reduced, but the LED temperature Resulted in an extreme rise.
In Examples 3 and 4, a glass epoxy substrate is used as the elongated substrate. On the back surface of the substrate, a heat transfer layer composed of an elongated graphite sheet over the entire length and a heat radiation composed of a PET sheet on the outer surface thereof. By sticking the layer, the temperature of the LED was about 78 ° C. at the central portion as compared with Comparative Example 2, and the temperature could be drastically reduced, and sufficient heat dissipation was obtained. This is the same in the case of Examples 11 and 12. The weight of the heat transfer layer made of the graphite sheet and the heat radiation layer made of the PET sheet is 30 mm in width, 1178 mm in the length in the longitudinal direction, and 4.6 g when the thickness is 25 μm, and the thickness is 40 μm with the same width and length. In this case, since the weight is very light at 5.6 g, the weight of Examples 3 and 4 is only slightly increased compared to Comparative Example 2, and the weight is reduced by 20 g or more compared to Comparative Example 1 using an aluminum substrate. I was able to. This is the same in the case of Examples 11 and 12 in which the width of the heat transfer layer and the heat dissipation layer is 40 mm and the structure is a specific shape.

  Next, the case where an aluminum substrate or a laminate of an aluminum substrate body and an insulating layer is used as an elongated substrate will be considered. As in Comparative Example 3, when the thickness of the substrate was doubled compared to Comparative Example 1, the temperature reduction effect was reduced by 2 ° C. at the temperature of the central portion, even though the weight increased by 88 g. Only a slight effect was obtained. On the other hand, when the heat transfer layer made of a graphite sheet is provided on the back surface of the aluminum substrate over the entire length in the longitudinal direction as in Examples 1 and 2, and the heat dissipation layer is provided on the outer surface, the weight increase is 5 g compared to Comparative Example 1. In addition to the slight degree, a temperature reduction effect of about 5 ° C. could be obtained at the temperature at the center. This is the same as in the case of Examples 9 and 10 in which the structures of the heat transfer layer and the heat dissipation layer have a specific shape.

  Further, it was found that the same temperature reduction effect can be obtained by arranging the graphite sheet constituting the heat transfer layer between the aluminum substrate body and the insulating layer as in Examples 5 and 6. . However, as in Examples 1 and 2, compared to the case where a heat transfer layer made of an elongated graphite sheet is provided on the back surface of the substrate and a heat radiation layer is provided on the outer surface of the substrate, the surfaces of Examples 5 and 6 are compared. When a heat transfer layer made of an elongated graphite sheet is provided between the substrate and the insulating layer as described above, the temperature at the center is about 1.5 ° C., but the temperature is high. became. This is thought to be due to the difference in thermal diffusion efficiency due to surface radiation. When the heat transfer layer and the heat dissipation layer are not provided on the back surface of the substrate as in the fifth and sixth embodiments, the heat dissipation due to the radiation is reduced because the emissivity of the aluminum substrate is low. On the other hand, in Examples 1 and 2, since the PET sheet having a high emissivity is provided on the outer surface of the graphite sheet constituting the heat transfer layer, the heat radiation effect by radiation is higher than that of aluminum, and from the graphite sheet on the back surface of the substrate. It is considered that the heat dissipation effect was enhanced when the heat transfer layer and the heat dissipation layer made of PET sheet were provided on the outer surface.

  Further, when a glass epoxy substrate is used as the elongated substrate and an aluminum plate is used as the heat radiating member (Examples 7 and 8), the glass plate is formed rather than the aluminum plate directly provided on the glass epoxy substrate as in Comparative Example 4. The heat dissipation effect was higher when a heat transfer layer made of graphite sheet was interposed between the epoxy substrate and the aluminum plate. This is considered to be because the graphite sheet acts like a cushion by sandwiching the graphite sheet between the glass epoxy substrate and the aluminum plate, the contact resistance can be reduced, and the heat transfer is improved. Thus, even in the case where a heat dissipation component such as a heat sink such as an aluminum plate is mounted on the substrate, by providing a heat transfer layer made of a graphite sheet over the entire length in the longitudinal direction of the substrate, the heat transfer property is further improved. It is considered that a further heat dissipation effect can be obtained.

1 Line illuminator 2 LED
3 Substrate 4 Body portion 5 Support portion 6 Cover 7 Cap 8 Insulating layer 9 Aluminum substrate (aluminum substrate)
DESCRIPTION OF SYMBOLS 10 Heat transfer layer 11 Heat dissipation layer 12 Connection pin 13 Hook 14 Translucent tube 15 Graphite sheet 16 Adhesive material layer 17 Glass epoxy board 18 Heat transfer layer 19 Heat dissipation layer (aluminum plate)
20 heat dissipation layer 21a, b side end 22a, b of heat dissipation layer 20 side end 23 of graphite sheet 15 adhesive layer 23
24a, b Side end portion 25 of the adhesive material layer 25 Substrate side end portion 26 Inner surface side 27 of the translucent tube 14 Extension portion 28 Small hole 29 Fin-like protrusion 30 Surface 31 opposite to the LED 2 of the substrate 17 Core Material 32 Aluminum board body (aluminum board body)
33 Insulating layer 34 Heat transfer layer 35 Inner cylinder 36 Outer cylinder 37 Lid 37
38 Container 39 Hole 40 Translucent tube 41 Substrate 42 Cap 43 Main body 44 Line illuminator 45 Layer 45 composed of heat transfer layer and heat dissipation layer
46 Extension part 47 Core material L Longitudinal length W Short side length H Height of main body part h1 Length of extension part 46 Height of cylindrical layer 45 having core material 47 in the inner cavity part Width w1 Width closely adhered to the substrate 41 and the inner surface of the translucent tube 40

Claims (23)

An elongated substrate in which a plurality of LEDs are arranged along the longitudinal direction;
A line-shaped illuminating device comprising a main body having an elongated shape that supports both side ends of the substrate in the longitudinal direction,
A line-shaped illuminating device, wherein a heat transfer layer including a graphite sheet having an elongated shape extending in the longitudinal direction of the substrate is provided on the surface of the substrate opposite to the LED or inside the substrate.   The line-shaped lighting fixture of Claim 1 which provided the thermal radiation layer which consists of a thermal radiation member in the outer surface of the heat-transfer layer provided in the said board | substrate surface.   The line-shaped lighting device according to claim 2, wherein a side end portion of the heat dissipation layer is bent so as to cover a side end portion facing the heat transfer layer.   The line illuminator according to claim 2 or 3, wherein the heat dissipation member is made of a polyethylene terephthalate sheet, a polyethylene sheet, a polypropylene sheet, an acrylic polymer sheet, a silicone polymer sheet, or an aluminum plate.   The linear illumination tool according to any one of claims 2 to 4, wherein the emissivity of the heat dissipating member is 0.9 or more.   The line illuminator according to any one of claims 1 to 5, wherein the heat transfer layer is provided with an adhesive layer on an inner surface side which is the substrate side.   The line-shaped lighting device according to claim 6, wherein a side end portion of the adhesive material layer is bent so as to cover a side end portion facing the graphite sheet.   The line-shaped lighting device according to any one of claims 2 to 6, wherein the heat transfer layer is provided with an adhesive layer on an outer surface side that is the heat radiation layer side. The substrate is composed of a substrate body and an insulating layer on the side holding the LED,
The line-shaped lighting device according to claim 1, wherein the heat transfer layer is interposed between a substrate body and an insulating layer of the substrate.   The line-shaped lighting device according to claim 9, wherein the heat transfer layer is provided with an adhesive layer on a surface side which is a substrate body side.   The line-shaped lighting device according to claim 1, wherein a heat transfer layer including an elongated graphite sheet extending in the longitudinal direction of the substrate is also provided on the LED side surface of the substrate.   The linear lighting device according to any one of claims 1 to 11, wherein a ratio (long / short) of a length in a longitudinal direction and a length in a short direction of the substrate is 10 or more.   The line-shaped lighting device according to claim 12, wherein a length of the substrate in a short direction is 30 mm or less.   The line lighting device according to any one of claims 1 to 13, wherein an area ratio of the substrate and the heat transfer layer (heat transfer layer / substrate) is 0.9 or less.   The line-shaped lighting fixture in any one of Claims 1-14 with which the both-sides edge part of the said heat-transfer layer is further extended from the board | substrate side edge part to the said main-body-part inner surface side.   The line lighting device according to any one of claims 1 to 15, wherein a small hole is provided between the substrate and the heat transfer layer.   The line-shaped lighting fixture in any one of Claims 1-8, 11-16 in which the said heat-transfer layer is bent by the fin shape with respect to the said board | substrate.   The heat transfer layer is formed in a cylindrical shape by sticking both end portions thereof, and a part or the whole of the outer surface is supported in close contact with the surface of the substrate opposite to the LED and the inner surface of the main body. The line-shaped lighting fixture in any one of Claims 1-8 and 11-16.   The line lighting device according to any one of claims 1 to 18, wherein the graphite sheet has a thermal conductivity of 1000 W / mK or more, a thickness of 10 to 50 µm, and an MIT bending life of 10,000 times or more.   The line lighting device according to any one of claims 1 to 19, wherein the substrate has a thermal conductivity of 120 W / mK or less and a thickness of 1.5 mm or less.   The line-shaped lighting device according to any one of claims 1 to 20, wherein the main body portion is made of a translucent tube.   The line illuminator according to claim 21, wherein the translucent tube is formed of one or more selected from polycarbonate resin, acrylic resin, polyethylene terephthalate resin, olefin resin, and silicone resin. The weight of the said board | substrate and the said graphite sheet is 80 g or less, The linear lighting fixture in any one of Claims 1-22.

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