JP2011096416A - Led lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a LED lighting fixture capable of restraining progress deterioration of heat radiation of the LED lighting fixture which uses a LED as a light source and reducing variations of the heat radiation for each LED lighting fixture. <P>SOLUTION: In the LED lighting fixture including a light source unit 5 having a wiring board 2 where LEDs are mounted, a fixture case 7 having a mounting surface 6 where the light source unit 5 is mounted, a mounting means 9 for fixing the light source unit 5 on the fixture case 7 by sticking to a mounting surface 6 of the fixture case 7, and a power supply section 11 for supplying power to the light source unit 5, a contact section 10 for making a back surface 8 of the light source unit 5 stick to the mounting surface 6 of the fixture case 7 is made of a material composed of a ceramic. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an LED lighting apparatus including an LED as a light source.

  With the recent increase in luminous efficiency and luminous flux of white LEDs, the movement of using white LEDs for general lighting applications is becoming full-scale. Here, as a LED lighting fixture for general illumination using a white LED as a light source, a wiring board on which a single or a plurality of surface-mounted LED packages are mounted, or a wiring on which a single or a plurality of LED chips are mounted. The form which fixed the board | substrate to the instrument housing | casing of LED lighting fixture is common. Hereinafter, a component that includes a wiring board on which at least one of a surface-mount type LED package and an LED chip is mounted, and that can be attached to an instrument housing, is referred to as a light source unit.

  Even in the current situation where the luminous efficiency of LEDs such as white LEDs has improved, about 70% of the electric power injected into the LEDs changes to heat. In general, the luminous efficiency and life of LEDs, which are semiconductor components, decrease as the LED temperature rises. Therefore, in LED lighting fixtures using the above-mentioned light source unit, the heat generated by the LEDs is dissipated to the fixture housing side. By doing so, it is necessary to lower the temperature of the LED. Here, the emission color of the LED is not limited to white.

  By the way, as an LED lighting fixture considering that heat generated by the LED of the light source unit is dissipated to the fixture housing side, for example, as shown in FIG. 8, a light source unit in which a plurality of LEDs 1 ′ are mounted on a wiring board 2 ′. A light source unit using a screw (not shown) or the like so that 5 ′ is in close contact with the mounting surface 6 ′ of the instrument housing 7 ′ formed of a metal such as aluminum, aluminum alloy or stainless steel having good thermal conductivity The thing which fixed 5 'to the instrument housing | casing 7' is proposed (for example, refer patent document 1).

JP 2002-33006 A

  In the LED lighting apparatus having the configuration shown in FIG. 8, a metal such as aluminum that is resistant to oxidation is used as the material of the instrument housing 7 ′. Oxidation progresses gradually, the thermal conductivity decreases, and the unevenness of the mounting surface 6 ′ of the instrument housing 7 ′ increases, so that the wiring board 2 ′ and the instrument housing 7 ′ of the light source unit 5 ′ Since the adhesiveness is also reduced, the heat dissipation from the light source unit 5 ′ to the fixture housing 7 ′ side is reduced compared to the initial stage, which may affect the long-term reliability of the LED lighting fixture.

  Further, since the above-described instrument housing 7 'is manufactured by a die casting method, the surface roughness of the mounting surface 6' of the instrument housing 7 'is large. Here, regarding the surface roughness, with respect to the arithmetic average roughness Ra specified in JIS B 0601-2001 (ISO 4287-1997), the arithmetic of the mounting surface 6 ′ of the instrument housing 7 ′ manufactured by the die casting method is used. The average roughness Ra is usually about 50 μm. Therefore, there is a large variation in the adhesion between the light source unit 5 ′ and the instrument housing 7 ′ for each LED lighting fixture product, and there is a large variation in the heat dissipation property for each product. Further, in order to improve the adhesion between the light source unit 5 ′ and the instrument housing 7 ′, a resin sheet or resin paste made of silicone resin or the like may be sandwiched between the light source unit 5 ′ and the instrument housing 7 ′. It is conceivable that when removing the light source unit 5 ′ from the instrument housing 7 ′, the resin sheet is torn, or a part of the resin sheet is stuck on the mounting surface 6 ′ of the instrument housing 7 ′ and cannot be removed. An LED lighting device using a resin sheet or a resin paste in order to improve the adhesion between the unit 5 ′ and the device housing 7 ′ is not suitable for replacing the light source unit 5 ′.

  The present invention has been made in view of the above-mentioned reasons, and the purpose thereof is to suppress a decrease in heat dissipation from a light source unit having an LED as a light source to the appliance housing side with the passage of time. It is providing the LED lighting fixture which can reduce the dispersion | variation in the heat dissipation for every goods.

  The invention according to claim 1 is a light source unit comprising an LED as a light source, an instrument housing formed of metal and having an attachment surface to which the light source unit is attached, and a light source unit in close contact with the attachment surface of the instrument housing, An LED lighting apparatus having an attachment means to be fixed to the instrument housing and a power supply unit for feeding power to the light source unit, wherein a contact portion that closely contacts the back surface of the light source unit on the attachment surface of the instrument casing is made of a ceramic material It is characterized by that.

  According to the present invention, the contact portion that closely contacts the back surface of the light source unit on the mounting surface of the instrument housing has a thermal conductivity close to the thermal conductivity of the metal of the instrument housing compared to a resin such as silicone resin. By using a material made of ceramics that is much less likely to deteriorate than metal, it is possible to suppress deterioration over time of the contact portion that closely contacts the back surface of the light source unit on the mounting surface of the instrument housing. The long-term reliability of the LED lighting apparatus can be improved.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the attachment means also serves as a removal means for removing the light source unit from the instrument housing.

  According to this invention, since the attachment means also serves as a removal means, the light source unit can be removed from the instrument housing, and the light source unit can be replaced with a new light source unit. Sometimes it is possible to prevent deterioration of the back surface of the light source unit over time. Therefore, the long-term reliability of the LED lighting apparatus can be improved.

  According to a third aspect of the present invention, in the second aspect of the present invention, the light source unit includes a power supply circuit unit for lighting the LED.

  According to the present invention, the LED and the power supply circuit unit can be exchanged at a time, and the heat generated in the power supply circuit unit can also be radiated from the light source unit to the appliance housing side.

  According to a fourth aspect of the present invention, in the second or third aspect of the present invention, in the light source unit, a conductive charging portion of the light source unit excluding the power feeding portion is covered with a non-charging portion that is an insulator. The mounting means has a mechanism for bringing the light source unit into close contact with the mounting surface of the instrument casing and fixing the light source unit to the instrument casing, and removing the mechanism from the instrument casing. And a means for detachably attaching the light source unit from the instrument housing.

  According to this invention, since the charging part except the power feeding part of the light source unit is covered and insulated by the non-charging part, there is no danger of electric shock, and the attachment means itself is removed from the instrument housing. In addition, since the light source unit can be replaced, it is possible for a general consumer who does not have a qualification such as an electrician to replace the light source unit and to prevent the attachment means from being lost. .

  According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the contact portion is formed by one surface side of a plate material made of ceramics.

  According to this invention, the contact portion is a plate made of ceramics that is superior in precision workability compared to metal, so that the flatness of the mounting surface of the instrument housing is improved, and the back surface of the light source unit and the Adhesiveness with an appliance housing is improved, and variation in heat dissipation for each product of the LED lighting fixture can be reduced.

  The invention of claim 6 is characterized in that, in the invention of claim 5, the plate member is fixed to the instrument housing through a bonding layer made of a flexible adhesive.

  According to this invention, when the light source unit is attached to the instrument housing, the stress applied to the plate material can be absorbed by the bonding layer, and the plate material can be prevented from being damaged.

  According to a seventh aspect of the present invention, in the fifth aspect of the present invention, the plate member has a metal film deposited on the other surface side opposite to the one surface side, and the instrument housing is interposed via a bonding layer made of solder. It is characterized by being joined to the body.

  According to the present invention, the light source unit is formed by bonding the plate material to the mounting surface of the instrument housing via a bonding layer made of solder having a higher thermal conductivity than a resin such as a silicone resin. The heat dissipation from the appliance housing side can be improved.

  According to an eighth aspect of the present invention, in the fifth aspect of the present invention, the instrument housing has a concave groove for positioning the plate material formed on a surface facing the back surface of the light source unit, and the opening shape of the concave groove is defined as the plate material. It is set so that a gap may be formed between the outer peripheral edge of the groove and the inner surface of the concave groove.

  According to this invention, the opening shape of the concave groove is set so that a gap is formed between the outer peripheral edge of the plate material and the inner side surface of the concave groove. In the process of joining to each other, the plate material can be easily positioned. In addition, when the plate member is bonded to the instrument housing, the other part of the mounting surface of the instrument casing is soiled by the protrusion of an adhesive such as a resin used for joining the plate member and the instrument casing. In addition, it is possible to prevent the plate material from moving and being displaced in the process of curing the adhesive.

  A ninth aspect of the invention is characterized in that, in the first to fourth aspects of the invention, the contact portion is formed by the surface of a thin film in a metal member covered with a thin film made of ceramics.

  According to this invention, since the contact portion is formed by the surface of a thin film coated with a metal member, the flatness of the mounting surface of the instrument housing is improved, and the back surface of the light source unit and the instrument housing are improved. Adhesion with the body is improved, and variation in heat dissipation for each product of the LED lighting apparatus can be reduced.

  In addition, the disadvantage of the mechanically brittle ceramics can be improved by the structure of the present invention, and the damage of the contact portion can be prevented, so that the yield at the time of manufacturing the LED lighting apparatus is improved and the long-term reliability of the LED lighting apparatus is improved. Improves. Furthermore, the thickness of the thin film covering the metal member can be made thinner than the thickness of the ceramic plate as in claims 5 to 8, and the instrument housing and the metal member are fixed by, for example, screwing Accordingly, the bonding layer as in claims 6 and 7 is also unnecessary, so that heat dissipation from the light source unit to the instrument housing side can be achieved as compared with the case of using a ceramic plate as in claims 5 to 8. Can be improved.

  A tenth aspect of the invention is characterized in that, in the first to ninth aspects of the invention, the ceramic material is a material that does not fall below the thermal conductivity of aluminum nitride.

  According to this invention, the material made of the ceramic is made of a material that does not fall below the thermal conductivity of aluminum nitride, so that the silicone resin is attached to the contact portion that closely contacts the back surface of the light source unit on the mounting surface of the instrument housing. As compared with the case of using a resin such as the above, it is possible to improve the heat dissipation from the light source unit to the instrument housing side.

  According to the first aspect of the present invention, the contact portion for bringing the back surface of the light source unit into close contact with the mounting surface of the instrument housing is made of a ceramic material, so that the back surface of the light source unit is brought into close contact with the mounting surface of the instrument housing. Since deterioration with time of the contact portion can be suppressed, there is an effect that the long-term reliability of the LED lighting apparatus is improved.

It is a schematic sectional drawing which shows the LED lighting fixture of Embodiment 1. The light source unit of an LED lighting fixture same as the above is shown, (a) is a schematic sectional drawing, (b) is a schematic plan view. The fixture housing | casing of an LED lighting fixture same as the above is shown, (a) is a schematic sectional drawing, (b) is a schematic plan view. The light source unit of an LED lighting fixture same as the above is shown, (a) is a schematic sectional drawing, (b) is a schematic plan view. The fixture housing | casing of the LED lighting fixture of Embodiment 3 is shown, (a) is a schematic sectional drawing, (b) is a schematic plan view. It is a schematic sectional drawing which attached the light source unit to the instrument housing | casing of the LED lighting fixture same as the above. The fixture housing | casing of the LED lighting fixture of Embodiment 4 is shown, (a) is a schematic sectional drawing, (b) is a schematic plan view. It is sectional drawing of the LED lighting fixture which shows a prior art example.

(Embodiment 1)
Hereinafter, the LED lighting fixture of this embodiment is demonstrated, referring FIGS. 1-3.

  The LED lighting fixture of this embodiment is an LED lighting fixture that can be used for a ceiling-embedded downlight or the like, and as shown in FIG. 1, a plurality of (in the illustrated example, five) LEDs 1 are on one surface side. A disc-shaped wiring board 2 mounted on the lower surface side in FIG. 1 and a disc-shaped wiring board 2 formed of a light-transmitting material and spaced apart from the wiring board 2 on the one surface side of the wiring board 2 A light source unit 5 having a cover plate 3, a cylindrical decorative frame 4 that holds the wiring board 2 and the cover plate 3 apart from each other, and a mounting surface 6 to which the light source unit 5 is attached, An instrument case 7 in which a portion serving as a heat dissipation path from the attachment surface 6 is formed of metal such as aluminum, aluminum alloy, stainless steel, an attachment means 9 for closely attaching and fixing the light source unit 5 to the instrument case 7, and an instrument case Take body 7 The ceramic plate 10 is brought into close contact with the rear surface 8 of the light source unit 5 in the plane 6, and a power supply unit 11 for supplying power to the light source unit 5.

  The power supply unit 11 is connected to the first connector 12 held on the wiring board 2 of the light source unit 5 and the distal end portion of the cable 38 connected to the power supply unit (not shown) installed outside the instrument housing 7. The second connector 17 is provided and held by the instrument housing 7 and detachably connected to the first connector 12. In the present embodiment, the first connector 12 is constituted by a male connector, and the second connector is constituted by a female connector.

  Each LED 1 of the light source unit 5 has a white emission color and uses an LED chip housed in a surface-mount package. However, the LED 1 is not limited to this and includes a single LED chip and emits light. The color is not limited to white.

  The wiring board 2 is formed of a metal base printed wiring board. As shown in FIG. 2, a connector mounting hole 36 into which the first connector 12 is inserted is provided in the peripheral portion of the wiring board 2. The connector 12 is attached. Further, the wiring board 2 is configured such that a conductor pattern (not shown) serving as an input end of a series circuit (or a parallel circuit or the like) of the plurality of LEDs 1 is electrically connected to the first connector 12 via an electric wire 44. Yes. The wiring board 2 is not limited to a metal base printed wiring board but may be a glass epoxy board or the like. However, a metal-based printed wiring board is preferable for improving heat dissipation.

  The cover plate 3 is made of a translucent material (for example, silicone resin, acrylic resin, glass, etc.) and is fixed to the decorative frame 4 of the light source unit 5.

  The decorative frame 4 is formed in a cylindrical shape with resin, and is formed with a step portion 37 for positioning and holding the wiring board 2 at one end portion, and for positioning and holding the cover plate 3 at the other end portion. Step 40 is formed.

  Further, the cover plate 3 and the decorative frame 4 are disposed between the wiring board 2 so as to cover each LED 1 mounted on the one surface side of the wiring board 2. The cover plate 3 is not limited to a flat plate shape. For example, a light distribution lens portion may be provided integrally or separately for each portion corresponding to each LED 1.

  As shown in FIG. 3, the instrument housing 7 is protruded from a disk-shaped heat sink portion 15 made of metal (here, aluminum) and a surface opposite to the light source unit 5 side of the heat sink portion 15. A plurality (six in the illustrated example) of fin portions 14 made of metal (here, aluminum), a cylindrical frame portion 16 constituting the side wall of the instrument housing 7, and the mounting surface 6 of the instrument housing 7 And a ceramic plate 10 that closely contacts the back surface 8 of the light source unit 5.

  Further, the fin portion 14 and the heat sink portion 15 are produced by an aluminum die casting method and are formed continuously and integrally.

  In addition, a connector attachment hole 41 into which the second connector 17 is inserted is provided in the peripheral portion of the heat sink portion 15, and the second connector 17 is attached thereto. Further, when the light source unit 5 is attached to the instrument housing 7, the second connector 17 is retracted from the attachment surface 6 of the instrument housing 7 as shown in FIG. 3 so as not to interfere with members on the light source unit 5 side. Attached.

  The frame portion 16 is made of resin and is screwed to the side surface of the heat sink portion 15 with a plurality (three in the illustrated example) of fixing screws 45.

  In addition, when attaching the LED lighting fixture of this embodiment to the construction material which consists of ceiling materials, for example, the appliance housing | casing 7 is inserted into the circular attachment hole (not shown) pierced by the construction material from the downward direction. The peripheral portion of the mounting hole in the construction material may be held between the flange portion 43 of the frame portion 16 and the mounting spring (not shown) attached to the instrument housing 7.

  The ceramic plate 10 is bonded to the mounting surface 6 of the instrument housing 7 via a bonding layer 29 made of an adhesive. Here, it is preferable to use a resin containing a filler with high heat dissipation. Note that the material of the bonding layer 29 is not limited to a resin containing a highly heat radiating filler, and may be any material that can fix the ceramic plate 10 to the mounting surface 6 of the appliance housing 7, for example, silver paste A conductive material such as the above may be used, but a material rich in air and moisture barrier properties is preferable so that the attachment surface 6 of the fixture housing 7 to which the light source unit 5 is attached can be prevented from deterioration over time. In addition, the material of the bonding layer 29 for bonding the ceramic plate 10 to the mounting surface 6 of the appliance housing 7 is more effective in improving the heat dissipation when a material having higher thermal conductivity than a resin such as silicone resin is used. So good. Further, the thickness of the bonding layer 29 for bonding the ceramic plate 10 to the mounting surface 6 of the instrument housing 7 is as thin as possible, and the one in contact with the entire back surface of the ceramic plate 10 is It is good because the thermal resistance between the two decreases and the heat dissipation improves. Moreover, when the light source unit 5 is attached to the instrument housing 7, the material of the bonding layer 29 can absorb the stress applied to the ceramic plate 10 by the bonding layer 29 and damage the ceramic plate 10. This is preferable because it can be prevented.

  As the ceramic plate 10, a plate material made of ceramic produced by a doctor blade method is used. The doctor blade method is a general method for producing the ceramic plate 10, but the surface roughness of the ceramic plate 10 is smaller than the surface roughness of the mounting surface 6 of the appliance housing 7 produced by the aluminum die casting method. Therefore, it is not necessary to polish the surface of the ceramic plate 10. For example, when comparing the surface roughness with the arithmetic average roughness Ra, the normal arithmetic average roughness Ra of the mounting surface 6 of the instrument housing 7 manufactured by the aluminum die casting method is about 50 μm, whereas the doctor The arithmetic average roughness Ra of the ceramic plate 10 produced by the blade method is about 3 μm. Therefore, the flatness of the mounting surface 6 of the instrument housing 7 is improved by using the ceramic plate 10 that is excellent in precision workability compared to a metal such as aluminum for the mounting surface 6 of the instrument housing 7. Adhesiveness between the back surface 8 and the fixture housing 7 is improved, and variation in heat dissipation for each product of the LED lighting fixture can be reduced.

  Moreover, although the aluminum nitride is employ | adopted as a raw material of the ceramic board 10, it is not restricted to aluminum nitride, For example, semiconductors, such as an oxide of metal elements, such as an alumina and a zinc oxide, or nitride, a carbide | carbonized_material, or silicon nitride Elemental oxides, nitrides, carbides, boron nitrides and carbides such as boron nitride, carbon nitrides, graphite, diamond-like carbon, and other ceramics made of carbon nitrides and allotropes, Further, it may be an oxide containing a plurality of types of elements selected from metal elements, semiconductor elements, boron, and carbon, or a ceramic made of nitride or carbide. All of these ceramics have a thermal conductivity close to that of metal and are much less susceptible to deterioration than metal, so that the surface state of the ceramic plate 10 can be stabilized over a long period of time. Can be made. Therefore, the light source unit 5 can be used as a tool compared to a structure in which the light source unit 5 is fixed using screws or the like so as to be in close contact with the mounting surface 6 of the tool housing 7 formed of aluminum, aluminum alloy, or stainless steel. Since the temporal deterioration of the heat dissipation to the housing 7 side can be suppressed, there is an effect that the long-term reliability of the LED lighting apparatus is improved.

  Among the materials described above, aluminum nitride has a thermal conductivity (about 200 W / (m · K)) close to that of aluminum (238 W / (m · K)). Therefore, if a material that does not fall below the thermal conductivity of aluminum nitride, such as silicon carbide, is used, the light source unit 5 moves to the device housing 7 side as compared with the case where aluminum or an aluminum alloy is used as the material of the device housing 7. Therefore, the temperature rise of each LED 1 can be suppressed at the same level as the case where the light source unit 5 is brought into close contact with the mounting surface 6 of the appliance housing 7 without using the ceramic plate 10.

  When the thickness of the ceramic plate 10 is thinner, or when the plane area of the ceramic plate 10 is equal to or smaller than the plane area of the back surface 8 of the light source unit 5, the closer to the flat area of the back surface 8, the more the thermal resistance of the ceramic plate 10 is. The ceramic plate 10 is more fragile as the thickness of the ceramic plate 10 is thinner or the plane area of the ceramic plate 10 is larger. Practically, the thickness of the ceramic plate 10 is about 0.1 to 2.0 mm, and the plane area of the ceramic plate 10 is the light source unit from each LED 1 mounted on the one surface side of the wiring board 2 when the light source unit 5 is attached. It is preferable that the ceramic plate 10 be present in the entire projection area on the back surface 8 side of the plate 5. Further, depending on the contact portion where the mounting surface 6 of the instrument housing 7 and the back surface 8 of the light source unit 5 are in close contact with each other and the thermal conductivity of the members constituting the wiring board 2, a sufficient heat radiation effect can be obtained.

  Further, as shown in FIG. 3, the ceramic plate 10 has a square shape, but is not limited to a square shape, and may be, for example, a rectangular shape, a parallelogram shape, a regular hexagonal shape, a circular shape, or the like. The number of ceramic plates 10 is not limited to one and may be plural. In the case of plural ceramic plates 10, it is desirable to spread the ceramic plates 10 on the mounting surface 6 of the instrument housing 7 without a gap. In consideration of the brittleness of the ceramic plate 10, it is better to use a plurality of ceramic plates 10 having a small plane area than to use only one ceramic plate 10 having a large plane area. For example, when the light source unit 5 is attached to the instrument housing 7, a plurality of flat areas are small in the entire projection region from each LED 1 mounted on the one surface side of the wiring board 2 to the back surface 8 side of the light source unit 5. By disposing the ceramic plate 10, heat dissipation is not impaired.

  As shown in FIG. 3, the mounting surface 6 of the appliance housing 7 is provided with a concave groove 20 for positioning the ceramic plate 10, and the opening shape of the concave groove 20 is the outer peripheral edge of the ceramic plate 10 and the concave portion. It is set so that a gap is formed between the groove 20. In other words, the opening size of the groove 20 is set slightly larger than the plane area of the ceramic plate 10. Therefore, in the process of fixing the ceramic plate 10 to the mounting surface 6 of the instrument housing 7, the position of the ceramic plate 10 can be easily determined, and the ceramic plate 10 is made of an adhesive that fixes the ceramic plate 10 to the mounting surface 6 of the instrument housing 7. When a resin containing a filler with a high heat dissipation property is used for the bonding layer 29, other portions of the mounting surface 6 of the instrument housing 7 may become dirty due to the protrusion of the resin containing the filler with a high heat dissipation property, In the process of curing a resin containing a high filler, it is possible to prevent a problem that the ceramic plate 10 moves and a positional shift occurs. The concave groove 20 is formed shallower than the thickness of the ceramic plate 10 so that the ceramic plate 10 can come into surface contact with the back surface 8 of the light source unit 5.

  The ceramic plate 10 is fixed to the mounting surface 6 of the appliance housing 7 with a resin containing a highly heat-radiating filler. The ceramic plate 10 is one surface side of the ceramic plate 10 (the surface side on the light source unit 5 side). A metal film is deposited (metallized) on the other surface side (surface side on the mounting surface 6 side) opposite to that of the mounting surface 6 of the instrument housing 7 via a bonding layer (not shown) made of solder. It can also be joined. Thereby, compared with resin containing the filler with high heat dissipation, there exists an effect which the heat dissipation from the ceramic board 10 to the instrument housing | casing 7 improves by joining using solder with high heat conductivity. In addition, the heat sink part 15 of the instrument housing | casing 7 is produced as a flat member so that a solder reflow method etc. may be implemented easily. The heat sink portion 15 is preferably joined to the fin portion 14 of the instrument housing 7 with a screw or the like after being joined to the ceramic plate 10 with solder. Moreover, if the metal material of the heat sink part 15 of the instrument housing | casing 7 is copper or aluminum so that it may be suitable for solder joining, it is better to give the surface of the heat sink part 15 of the instrument housing | casing 7 tin plating.

  As shown in FIG. 3, the instrument housing 7 has three convex portions 21 protruding inwardly on the inner surface of the frame portion 16. Further, as shown in FIG. 3, these convex portions 21 are arranged so that the angle between the straight lines connecting the center of the instrument housing 7 and the center of the convex portion 21 in a plan view is 120 degrees. They are spaced apart at equal intervals in the circumferential direction.

  On the other hand, as shown in FIG. 2, the light source unit 5 has three concave portions 22 formed on the side surface of the decorative frame 4 so as to fit the convex portions 21. Further, as shown in FIG. 2, these recesses 22 are arranged in the circumferential direction of the light source unit 5 so that the angle between the straight lines connecting the center of the light source unit 5 and the center of the recess 22 in a plan view is 120 degrees. They are spaced apart from each other. Note that the light source unit 5 can be inserted inside the instrument housing 7 only when the protrusions 21 and the recesses 22 are aligned so as to be fitted. Also, with this structure, as shown in FIG. 1, the first connector 12 of the light source unit 5 and the second connector 17 of the instrument housing 7 can be easily connected.

  Further, as shown in FIG. 2, the collar portion 42 of the decorative frame 4 is provided with three screw insertion holes 23 through which the mounting screws 19 are inserted. Further, as shown in FIG. 2, these screw insertion holes 23 are formed so that the angle between the straight lines connecting the center of the light source unit 5 and the center of the screw insertion hole 23 in a plan view is 120 degrees. They are spaced apart at equal intervals in the circumferential direction. Further, as shown in FIG. 3, when the light source unit 5 is attached to the instrument housing 7, the distal end portion of the attachment screw 19 is screwed into the flange portion 43 of the frame portion 16 so that the screw insertion hole 23 is aligned. As shown in FIG. 3, the screw holes 24 to be joined are provided at three locations, and the angle between the straight lines connecting the center of the instrument housing 7 and the center of the screw hole 24 in a plan view is 120. It is spaced apart at equal intervals in the circumferential direction of the instrument housing 7 so as to be a degree. When the light source unit 5 is attached to the instrument housing 7, as shown in FIG. 1, the mounting screw 19 is aligned with the screw hole 24 of the instrument housing 7 through the screw insertion hole 23 of the light source unit 5, and attached. The light source unit 5 is fixed to the instrument housing 7 by screwing the screw 19 with a screwdriver or the like. The light source unit 5 can be fixed to the instrument housing 7 without damaging the ceramic plate 10 by adjusting the screw tightening force by a driver or the like. In the present embodiment, the attachment means 9 for attaching the light source unit 5 to the instrument housing 7 is constituted only by the attachment screw 19. When the light source unit 5 is removed from the instrument housing 7, the mounting screw 19 may be removed with a screwdriver or the like, and the light source unit 5 may be removed from the instrument housing 7. In short, in this embodiment, the attachment screw 19 which is the attachment means 9 also serves as a removal means for removing the light source unit 5 from the instrument housing 7.

  In the LED lighting fixture of the present embodiment described above, the contact portion that closely contacts the back surface 8 of the light source unit 5 on the mounting surface 6 of the fixture housing 7 is made of a ceramic material, so that Since deterioration can be suppressed and the flatness of the mounting surface 6 of the fixture housing 7 is improved, the adhesion between the back surface 8 of the light source unit 5 and the fixture housing 7 is improved. Variation in heat dissipation can be reduced. In addition, since the material made of ceramics is a material that does not fall below the thermal conductivity of aluminum nitride, the light source unit 5 is moved to the instrument housing 7 side as compared with the case where a resin such as silicone resin is used for the contact portion. Therefore, the long-term reliability of the LED lighting apparatus can be improved.

(Embodiment 2)
Hereinafter, although the LED lighting fixture of this embodiment is demonstrated, referring FIG. 4, the basic composition of the LED lighting fixture of this embodiment is the same as Embodiment 1, and the structure of the light source unit 5 is Embodiment 1. FIG. Since only the differences are noted, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  As shown in FIG. 4, the light source unit 5 of the present embodiment is a disk-shaped LED wiring board in which a plurality of (in the illustrated example, five) LEDs 1 are mounted on one surface side (upper surface side in FIG. 4). 32, a disc-shaped cover plate 3 formed of a translucent material and disposed on the one surface side of the LED wiring board 32 so as to be separated from the LED wiring board 32, and the LED wiring board 32 and the cover In addition to the cylindrical decorative frame 4 that holds the plate 3 in a separated form, a power supply circuit unit 25 for lighting each LED 1 is provided.

  The power supply circuit section 25 fixes a disk-shaped power supply wiring board 27 on which a plurality of circuit components 26 of the power supply circuit section 25 are mounted on one surface side (the lower surface side in FIG. 4), and the power supply wiring board 27. Heat generated from each LED 1 and each circuit component 26, a base portion 28 formed of a disk-shaped metal for bonding, a bonding layer 29 a made of an adhesive that fixes the power supply wiring board 27 to the base portion 28, and the like. A disk-shaped heat transfer plate 30 for transmitting to the appliance housing 7 side, and a cylinder formed of metal for transferring heat generated from each LED 1 and each circuit component 26 from the base portion 28 to the heat transfer plate 30. And a power supply unit 11 that supplies power to the light source unit 5. On the other side of the base part 28 to which the power supply wiring board 27 is fixed, the LED wiring board 32 is fixed to the base part 28 with a bonding layer 29b made of an adhesive. Further, the power wiring board 27 and the LED wiring board 32 transmit heat generated from each LED 1 and each circuit component 26 to the base portion 28 via the bonding layers 29a and 29b, and via the body portion 31, the light source unit. The heat is dissipated to the heat transfer plate 30 on the back surface 8 side of 5.

  As shown in FIG. 4, the heat transfer plate 30 and the body portion 31 are disposed between the base portion 28 and the power supply wiring board 27 fixed on one surface side of the base portion 28 so as to be fixed. It is fixed by a screw 46.

  In the power supply unit 11 of the present embodiment, the first connector 12 held by the heat transfer plate 30 of the light source unit 5 and the power supply wiring board 27 arranged away from the heat transfer plate 30 connect the electric wires 18. Is electrically connected. In addition, a connector mounting hole 36 is provided in the peripheral portion of the heat transfer plate 30, and the first connector 12 is inserted, and the connector terminal 13 of the first connector 12 and the power supply wiring board 27 connect the electric wires 18. Is electrically connected.

  The power supply wiring board 27 is formed of a metal-based printed wiring board, and as shown in FIG. ) And the connector terminal 13 of the first connector 12 are electrically connected via an electric wire 18. The power supply wiring board 27 is not limited to a metal-based printed wiring board but may be a glass epoxy board or the like. However, a metal-based printed wiring board is preferable for improving heat dissipation.

  Further, the LED wiring board 32 is formed of a metal base printed wiring, and as shown in FIG. 4, a conductor pattern (not shown) serving as an input end of a series circuit (or a parallel circuit or the like) of the plurality of LEDs 1. And a conductor pattern (not shown) serving as an output end of the power supply circuit section 25 in the power supply wiring board 27 are electrically connected via an electric wire 39. The LED wiring board 32 is not limited to a metal-based printed wiring board but may be a glass epoxy board or the like. However, a metal-based printed wiring board is preferable for improving heat dissipation.

  The bonding layers 29a and 29b made of an adhesive for fixing the power supply wiring board 27 and the LED wiring board 32 to the base portion 28 use a resin containing a filler with high heat dissipation. Here, the bonding layers 29a and 29b made of an adhesive are not limited to a resin containing a highly heat-dissipating filler, but are materials that can fix the power wiring board 27 and the LED wiring board 32 to the base portion 28, respectively. If it is. Further, the power supply wiring board 27 and the LED wiring board 32 may be fixed to the base portion 28 by screwing (not shown) or the like.

  In the LED lighting fixture of the present embodiment described above, the heat transfer plate 30 of the light source unit 5 is in close contact with the mounting surface 6 of the fixture housing 7, so that heat dissipation from the light source unit 5 to the fixture housing 7 side is improved. Can be made.

  In addition to the LED wiring board 32, the light source unit 5 includes the power supply circuit unit 25 for lighting the LED 1, so that the LED 1 and the power supply circuit unit 25 can be replaced at one time. Heat generated in the power supply circuit unit 25 can also be dissipated from the light source unit 5 to the instrument housing 7 side.

(Embodiment 3)
Hereinafter, although the LED lighting fixture of this embodiment is demonstrated, referring FIGS. 5-6, the basic composition of the LED lighting fixture of this embodiment is the same as Embodiment 2, and the light source unit 5 is set to fixture housing | casing. Since only the configuration of the attaching means 9 fixed to 7 is different, the same components as those in the second embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In the LED lighting apparatus of the present embodiment, as shown in FIG. 5, the attachment means 9 has a mechanism for bringing the back surface 8 of the light source unit 5 into close contact with the ceramic plate 10 and fixing the light source unit 5 to the apparatus housing 7. The mechanism includes a fastener 33 made of a leaf spring and a rivet 34 that rotatably supports the fastener 33 on the flange portion 43 of the frame portion 16. Here, in the LED lighting device of the present embodiment, three fasteners 33 are provided on the flange portion 43 of the frame portion 16, and as shown in FIG. They are arranged at equal intervals in the circumferential direction of the instrument housing 7 so that the angle between the straight lines connecting the centers is 120 degrees, and each fastener 33 is centered on the axis of the rivet 34 in plan view. It can be turned.

  When the light source unit 5 is attached to the instrument housing 7, the fastener 33 is rotated around the axis of the rivet 34 in plan view, and the light source unit 5 is attached to the instrument housing 7. The light source unit 5 is pressed against the instrument housing 7 side by the spring property of the fastener 33 by turning it back to the position where it overlaps with the light source unit 5, and the light source unit 5 is attached to the mounting surface of the instrument housing 7. 6 can be fixed in a certain direction while being pressed evenly. Further, by appropriately adjusting the spring strength suitable for fixing the fastener 33, the light source unit 5 can be fixed in close contact with the instrument housing 7 without damaging the ceramic plate 10. When removing the light source unit 5 from the instrument housing 7, the fastener 33 is rotated around the axis of the rivet 34 in plan view so that the fastener 33 does not overlap the light source unit 5. Is removed from the instrument housing 7. In short, also in this embodiment, the attaching means 9 also serves as a removing means for removing the light source unit 5 from the instrument housing 7. Therefore, the attachment means 9 of the present embodiment does not require a tool such as a screwdriver when attaching or detaching the light source unit 5 to / from the instrument housing 7, and there is no need to adjust the screw tightening force when replacing the light source unit 5. Since the attachment means 9 is fixed to the instrument housing 7, the attachment means 9 can be prevented from being lost.

  In the LED lighting apparatus of the present embodiment described above, the attachment means 9 for fixing the light source unit 5 to the attachment surface 6 of the instrument housing 7 and fixing the light source unit 5 to the instrument housing 7 is the above-described fastener 33 and the fastening device. The tool 33 is fixed to the flange portion 43 of the frame 16 of the instrument housing 7 with a rivet 34, and the light source unit 5 can be replaced without removing the fastener 33 from the instrument housing 7. The deterioration over time of the back surface 8 can also be improved, and the long-term reliability of the LED lighting apparatus is improved.

(Embodiment 4)
Hereinafter, although the LED lighting fixture of this embodiment is demonstrated, referring FIG. 7, the basic composition of the LED lighting fixture of this embodiment is the same as Embodiment 1, The ceramic board 10 demonstrated in Embodiment 1 is the same. Instead, the only difference is that a metal member 35 covered with a thin film made of ceramics is used. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  The metal member 35 covered with a thin film made of ceramic uses silicon carbide as a material for the thin film made of ceramic. In addition to silicon carbide as a material for thin films made of ceramics, oxides of metal elements such as alumina, aluminum nitride, titanium nitride, oxides of nitrides, carbides, oxides of semiconductor elements such as silicon nitride, or nitrides, It may be a carbide or a boron nitride or carbide such as boron nitride, or a carbon nitride, a ceramic material made of carbon nitride, graphite, diamond-like carbon, or the like. Furthermore, it may be a ceramic material made of an oxide, nitride, or carbide containing a plurality of types of elements selected from metal elements, semiconductor elements, boron, and carbon.

  In the LED lighting fixture of the present embodiment described above, the flatness of the mounting surface 6 of the fixture housing 7 is improved as in the first embodiment by using the metal member 35 covered with a thin film made of ceramics. Adhesion between the unit 5 and the appliance housing 7 is improved, and variations in heat dissipation for each product of the LED lighting fixture can be reduced. In addition, this embodiment can improve the disadvantages of mechanically fragile ceramics and prevent breakage of the ceramic plate 10 of Embodiment 1, so that the yield in the manufacture of LED lighting fixtures can be improved and the LED lighting fixtures can be manufactured. Long-term reliability is improved. Further, the thickness of the thin film covering the metal member 35 can be made thinner than the thickness of the ceramic plate 10, and the metal member 35 covered with the thin film made of ceramic is screwed (not shown) to the heat sink portion 15 of the instrument housing 7. Therefore, the bonding layer 29 made of an adhesive that fixes the metal member 35 covered with a thin film made of ceramics to the mounting surface 6 of the instrument housing 7 is also unnecessary. Therefore, compared with the ceramic plate 10, there is an effect that heat dissipation from the light source unit 5 to the instrument housing 7 side is improved.

1 LED
DESCRIPTION OF SYMBOLS 2 Wiring board 5 Light source unit 6 Mounting surface 7 Instrument housing 8 Back surface 9 Mounting means 10 Ceramics board 11 Feeding part 19 Mounting screw 20 Concave groove 25 Power supply circuit part 29 Joining layer 35 Metal member

Claims (10)

  A light source unit having an LED as a light source, an appliance housing formed of metal and having an attachment surface to which the light source unit is attached, and an attachment means for attaching the light source unit to the attachment surface of the appliance housing and fixing the light source unit to the appliance housing And a power supply unit for supplying power to the light source unit, wherein the contact portion for bringing the back surface of the light source unit into close contact with the mounting surface of the device housing is made of a ceramic material. .   2. The LED lighting apparatus according to claim 1, wherein the attaching means also serves as a removing means for removing the light source unit from the instrument housing.   The LED light fixture according to claim 2, wherein the light source unit includes a power supply circuit unit for lighting the LED.   In the light source unit, a conductive charging part of the light source unit excluding the power feeding part is covered with a non-charging part that is an insulator, and the attachment means attaches the light source unit to the appliance housing. It has a mechanism for closely attaching to the mounting surface and fixing the light source unit to the instrument housing, and comprises means for making the light source unit detachable without removing the mechanism from the instrument housing. The LED lighting fixture of Claim 2 or Claim 3.   5. The LED lighting apparatus according to claim 1, wherein the contact portion is formed by one surface side of a plate material made of ceramics.   6. The LED lighting apparatus according to claim 5, wherein the plate member is fixed to the apparatus housing via a bonding layer made of a flexible adhesive.   The plate material is formed by depositing a metal film on the other surface side opposite to one surface side of a plate material made of ceramics, and is bonded to the instrument housing via a bonding layer made of solder. The LED lighting apparatus according to claim 5.   The instrument housing is formed with a concave groove for positioning the plate material on a surface facing the back surface of the light source unit, and an opening shape of the concave groove is formed between an outer peripheral edge of the plate material and an inner side surface of the concave groove. The LED lighting apparatus according to claim 5, wherein the LED lighting apparatus is set so that a gap is formed.   5. The LED lighting apparatus according to claim 1, wherein the contact portion is formed by a surface of a thin film in a metal member covered with a thin film made of ceramics.   The LED lighting apparatus according to any one of claims 1 to 9, wherein the material made of ceramic is a material that does not fall below the thermal conductivity of aluminum nitride.

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