JP6226548B2 - Heat sink and lighting apparatus including the same - Google Patents

Description

  The present invention relates to a technology of a heat sink and a lighting fixture including the heat sink.

  Conventionally, a light source body including a light emitting element on a surface of a substrate is known (for example, see Patent Document 1). Such a light source body is called an LED module, and is used for a lighting fixture or the like. Such a luminaire dissipates heat from the light source body via the heat sink. As an example of the LED module, there is a COB (Chip on Board) type light emitting module in which a light emitting diode or a wiring pattern is formed on a substrate.

JP 2013-51375 A JP 2013-65456 A

  By the way, such a lighting fixture must be able to suppress the occurrence of a leakage current due to a lightning surge. More specifically, such a lighting apparatus must be able to suppress the occurrence of discharge from the substrate to the heat sink even when a large voltage is applied due to lightning. Therefore, in the conventional lighting fixture, it was set as the structure which inserts | pinches an insulating sheet between a light source body and a heat sink, and suppresses generation | occurrence | production of the discharge from a board | substrate to a heat sink (for example, refer patent document 2). However, from the viewpoint of cost reduction and productivity improvement, there has been a demand for a lighting fixture that eliminates the insulating sheet. An object of the heat sink disclosed in the present application is to provide a heat sink that can suppress the occurrence of discharge from a substrate with a simple configuration. An object of the lighting fixture disclosed in the present application is to provide a lighting fixture capable of suppressing the occurrence of discharge from a substrate to a heat sink with a simple configuration.

A lighting fixture disclosed in the present application is a lighting fixture including a light source body including a light emitting element on a surface of a substrate, and a heat sink that dissipates heat of the light source body, and the light source body includes a back surface of the substrate. It is attached to the heat sink in contact with the heat sink, and a groove portion is formed on the heat sink at least in a portion overlapping the conductor , and the groove portion has an outer surface that forms the groove portion outside the side surface of the substrate. Is formed .

In the luminaire disclosed in the present application, it is preferable that the groove is formed such that a spatial distance from a side surface of the substrate to the outer surface is longer than a distance at which generation of a leakage current due to a lightning surge can be suppressed .

In the lighting fixture disclosed in the present application, the lighting fixture includes a light source body including a light emitting element on a surface of a substrate, and a heat sink that dissipates heat of the light source body, and the light source body includes a back surface of the substrate. It is attached to the heat sink in contact with the heat sink, and a groove is formed in the heat sink at least in a portion overlapping with the conductor, and the inner surface of the groove is inside the side surface of the substrate. The groove portion is formed such that a creepage distance from a conductor provided on the substrate to the inner side surface is longer than a distance at which generation of a leakage current due to lightning surge can be suppressed.

A heat sink disclosed in the present application is a heat sink to which a substrate on which an electrical component is mounted is attached, and has a mounting surface to which the substrate is mounted. The mounting surface has a groove portion at least in a portion overlapping the conductor. The groove portion is formed such that the outer surface of the groove portion is formed outside the side surface of the substrate .

  According to the heat sink and the lighting fixture disclosed in the present application, it is possible to suppress the occurrence of discharge from the substrate to the heat sink with a simple configuration.

The figure which shows the structure of the lighting fixture 100. FIG. The figure which expanded the area | region Ra in FIG. The figure seen from the direction of arrow Xa in FIG. The perspective view of a heat sink. Top view showing the underside of the heat sink The figure which shows the C1-C1 cross section and C2-C2 cross section in FIG. The figure seen from the direction of arrow Xb and arrow Xc in FIG.

  First, the lighting fixture 100 which concerns on embodiment of this invention is demonstrated easily. As an example, the lighting device 100 is used as a downlight that is partly embedded in a ceiling or the like.

  FIG. 1 is a view showing the structure of the lighting apparatus 100. The direction parallel to the gravitational direction is defined as “vertical direction V”, and the direction perpendicular to the gravitational direction is defined as “horizontal direction H”.

  The luminaire 100 mainly includes a light source unit 1, a main body unit 2, and a power supply unit 3. Moreover, the lighting fixture 100 according to the present embodiment includes a holder 4.

  The light source unit 1 includes a light source body 11. In the present embodiment, the light source body 11 is a COB type light emitting module in which the light emitting element 13 is formed on the surface of the substrate 12. The light source body 11 is not limited to a COB type light emitting module, and the form thereof is not limited as long as it includes at least a light source such as an SMD (Surface mount device) type light emitting module in which an LED chip is mounted on a substrate surface. The light emitting element 13 is an LED (Light Emitting Diode). The light emitted from the light emitting element 13 is refracted by the shade 14, reflected by the reflector 15, and irradiated in an arbitrary direction. In addition, the light source body 11 in this embodiment is provided with two electrodes 12A and 12C on a substrate 12 (see FIGS. 6 and 7). The electrode 12A is a so-called anode, and is connected to the light emitting element 13 via the circuit 12Ac (see FIG. 7). The electrode 12C is a so-called cathode, and is connected to the light emitting element 13 via the circuit 12Cc (see FIG. 7). These conductors (electrodes 12A and 12C and circuits 12Ac and 12Cc) are arranged in the vicinity of the outer peripheral edge of the substrate 12 having a rectangular shape. The electrodes 12 </ b> A and 12 </ b> C are disposed in the vicinity of the opposite corners of the substrate 12. However, the arrangement of the conductor is not limited.

  The main body 2 includes a heat sink 21. In the present embodiment, the heat sink 21 is a cast part in which a plurality of fins 21F are formed on a case 21C. The heat sink 21 is formed of an aluminum alloy (for example, ADC 12) having high thermal conductivity in order to improve heat dissipation efficiency. The material of the heat sink 21 is not limited to aluminum as long as the heat conductivity is high. The heat generated by the light source body 11 is transmitted to the heat sink 21 and dissipated into the air. Note that the heat sink 21 in the present embodiment has a bracket 21B formed on the side portion of the fin 21F. The bracket 21B supports the power supply unit 3 and is provided with a passage 21Bp through which the electric wires 34 and 35 are passed.

  The power supply unit 3 includes a power supply device 31. In the present embodiment, the power supply device 31 includes an electrical component that constitutes a power supply circuit, a light control circuit, and the like, and a substrate 32 on which the electrical component is mounted. The power supply circuit converts an alternating current obtained from a commercial power supply into a direct current. The dimmer circuit adjusts the amount of current by controlling the amplitude or phase of the current. The heat generated by the power supply device 31 is transmitted to the power supply box 33 and dissipated into the air. Some heat may be transmitted from the power supply box 33 to the heat sink 21 and dissipated into the air. In addition, the power supply device 31 in the present embodiment is connected to the holder 4 via electric wires 34 and 35. The holder 4 holds the light source body 11 and connects the electrodes 12A and 12C and the electric wires 34 and 35 described above.

  Below, the detailed structure of the heat sink 21 is demonstrated.

  FIG. 2 is an enlarged view of a region Ra in FIG. FIG. 3 is a diagram viewed from the direction of the arrow Xa in FIG. FIG. 4 is a perspective view of the heat sink 21. FIG. 5 is a plan view showing the lower surface of the heat sink 21.

  The heat sink 21 is provided with a housing portion 21s. The accommodating portion 21s has a structure in which the flat surface 21R is surrounded by a substantially cylindrical wall. In addition, since the holder 4 mentioned above is attached to the plane 21R, this plane 21R is defined as "attachment surface 21A". In addition, although the shape of the wall surrounding the flat surface 21R is a substantially cylindrical shape, this shape is an example.

  The mounting surface 21 </ b> A is formed in parallel to the horizontal direction H. A screw hole (not shown) is provided in the mounting surface 21A in parallel to the vertical direction V. The holder 4 is provided with a through hole (not shown) at a position overlapping the screw hole. For this reason, the holder 4 is fixed to the mounting surface 21A by the screw 4S through the through hole. In order to hold the light source body 11, the holder 4 is formed with a recess 4 d according to the shape of the substrate 12 constituting the light source body 11. For this reason, the light source body 11 will be fixed to the attachment surface 21A in a state of being fitted in the recess 4d. That is, the light source body 11 is attached to the heat sink 21 with at least a part of the back surface 12b of the substrate 12 in contact with the attachment surface 21A (see FIG. 6).

  Furthermore, grooves 21d and 21d are formed on the mounting surface 21A so as to overlap a part of the substrate 12. That is, in the heat sink 21, grooves 21d and 21d are locally formed in a portion overlapping with a part of the back surface 12b of the substrate 12. Thus, the lighting fixture 100 according to the present embodiment is characterized in that the groove portions 21d and 21d are locally provided in a portion overlapping with a part of the back surface 12b of the substrate 12. Below, the technical effect by providing groove part 21d * 21d is demonstrated. Note that the two groove portions 21d and 21d in the present embodiment are independent of each other. The term “local” refers to a part of the mounting surface 21A that overlaps the substrate 12. In this embodiment, “local” refers to a position at least overlapping with the conductors (electrodes 12A and 12C and circuits 12Ac and 12Cc), but a portion other than the conductor in the substrate 12 may be included to some extent. . In addition, when the groove part 21d is formed in the position which overlaps with all the outer-periphery edge parts of the light source body 11, compared with the structure of this embodiment, the contact area of the board | substrate 12 and the heat sink 21 becomes narrow, and it becomes the structure of this embodiment. In comparison, the heat dissipation of the light source body 11 is lowered. In the present embodiment, the groove portion 21 d is locally formed in order to suppress the discharge from the light source body 11 to the heat sink 21 while ensuring high heat dissipation of the light source body 11.

  In the present embodiment, the groove portions 21 d and 21 d are formed following the shape of the substrate 12. Specifically, the groove portions 21d and 21d are formed in a bowl shape that is bent at a right angle in accordance with the shape of the substrate 12 that is rectangular in plan view (see FIGS. 4 and 5). . The groove portions 21d and 21d are formed at positions overlapping the conductors (electrodes 12A and 12C and circuits 12Ac and 12Cc) provided on the substrate 12 (see FIGS. 6 and 7).

  Thus, the light source body 11 is attached to the heat sink 21 with the back surface 12b of the substrate 12 in contact with the attachment surface 21A. Further, in the heat sink 21, grooves 21 d and 21 d are locally formed in a portion overlapping with a part of the back surface 12 b of the substrate 12. As a result, the lighting fixture 100 can provide a space between the heat sink 21 and the portion of the substrate 12 that constitutes the conductors (electrodes 12A and 12C and circuits 12Ac and 12Cc). It is possible to suppress the occurrence of discharge. In particular, when an overcurrent flows through the conductors (electrodes 12A and 12C and circuits 12Ac and 12Cc) of the substrate 12, it is possible to suppress discharge from the conductor to the heat sink 21. In addition, since the lighting fixture 100 has a structure that does not require an insulating sheet, the heat of the light source body 11 can be efficiently transmitted to the heat sink 21.

  The technical idea of this embodiment is that a space is provided between the heat sink 21 and the portion of the substrate 12 that constitutes the conductors (electrodes 12A and 12C and circuits 12Ac and 12Cc), and discharge from the substrate 12 to the heat sink 21 occurs. It is in the point which suppresses. That is, if the shape and position of the groove 21d overlaps at least the conductors (electrodes 12A and 12C and circuits 12Ac and 12Cc) of the substrate 12, the occurrence of discharge from the substrate 12 to the heat sink 21 is suppressed. Can do. Accordingly, the positions and shapes of the groove portions 21d and 21d can be appropriately changed depending on the arrangement of the conductors and the like, and are not limited to the aspects of the present embodiment.

  In the present embodiment, the groove 21d is locally formed on the substrate 12 as one of the features. Specifically, the groove 21d is formed at a position on the substrate 12 that overlaps at least the conductor. With such a configuration, a space can be formed between the conductor and the heat sink 21, and discharge from the conductor to the heat sink 21 can be suppressed. Moreover, since the contact area of the board | substrate 12 and the heat sink 21 can be ensured as much as possible, the heat dissipation of the light source body 11 can be ensured.

  If the groove 21d is formed at a position that overlaps all of the outer peripheral edge of the light source body 11, the contact area between the substrate 12 and the heat sink 21 is narrower than that of the configuration of the present embodiment, and The heat dissipation of the light source body 11 is lower than that of the configuration. If the heat dissipation of the light source body 11 is low, the temperature generated by the light source body 11 itself when the light source body 11 is turned on may reach a high temperature. When the light source body 11 becomes high temperature, there is a high possibility that the light becomes weak, the life of the light emitting element is shortened, or the light emitting element is damaged. In order to ensure heat dissipation in such a configuration, for example, a configuration in which an insulating sheet (a sheet that transmits heat but insulates electricity) is sandwiched between the substrate 12 and the heat sink 21 can be considered, but the number of components increases. However, there may be disadvantages such as an increase in cost and an increase in the number of assembly steps.

  On the other hand, in the present embodiment, since the groove portion 21d is locally formed, the contact area between the substrate 12 and the heat sink 21 can be ensured as much as possible, and therefore the light source body 11 without using an insulating sheet. Heat dissipation can be ensured. Therefore, since the temperature rise of the light source body 11 can be suppressed, it is possible to suppress the light emitted from the light emitting element from being weakened, to suppress the life of the light emitting element from being shortened, and to prevent the light emitting element from being damaged. Can be. Moreover, since this embodiment forms the groove part 21d locally, the discharge from the light source body 11 to the heat sink 21 can be suppressed. Moreover, it is preferable that the heat sink 21 has a configuration in which at least a region (excluding the groove portion 21d) in contact with the substrate 12 on the mounting surface 21A is smoothed. With such a configuration, the contact area between the back surface of the substrate 12 and the mounting surface 21 </ b> A is increased, and the heat generated by the light source body 11 can be efficiently transmitted to the heat sink 21.

  Next, the shape of the groove portions 21d and 21d in the present embodiment will be specifically specified, and the technical effects thereof will be described.

  FIG. 6 is a diagram showing a C1-C1 cross section and a C2-C2 cross section in FIG. 3. FIG. 7 is a diagram viewed from the directions of arrows Xb and Xc in FIG.

  As described above, the grooves 21d and 21d are formed in a bowl shape that is bent at a right angle in accordance with the shape of the substrate 12 that is rectangular when viewed in plan. That is, the groove portions 21d and 21d are formed in a part of the periphery of the region to which the substrate 12 is attached. Therefore, the inner wall surface constituting the groove portions 21d and 21d is defined as “inner surface 21iw” and the outer wall surface constituting the groove portions 21d and 21d is defined as “outer surface 21ow”. A wall surface that intersects the inner side surface 21iw and the outer side surface 21ow is defined as a “bottom side surface 21bw”.

  In the present embodiment, the inner side surface 21iw is provided at a position where it intersects the substrate 12 of the attached light source body 11. That is, in the groove portions 21d and 21d, the inner side surface 21iw constituting the groove portions 21d and 21d is formed on the inner side in the surface direction of the mounting surface 21A rather than the side surface 12s of the substrate 12.

  By setting it as such a shape, the board | substrate 12 will be fixed to the position which a part of this board | substrate 12 covers a part of groove part 21d * 21d. More specifically, since the groove portions 21d and 21d are formed at positions overlapping the conductors (electrodes 12A and 12C and circuits 12Ac and 12Cc) of the substrate 12, the substrate 12 has a groove portion at the portion where the conductor is provided. It is fixed at a position covering 21d and 21d.

  As described above, in the groove portions 21d and 21d, the inner surface 21iw constituting the groove portions 21d and 21d is formed on the inner side in the surface direction of the mounting surface 21A rather than the side surface 12s of the substrate 12. As a result, the lighting apparatus 100 can ensure a creepage distance Dx from the conductors (electrodes 12A and 12C and circuits 12Ac and 12Cc) provided on the substrate 12 to the inner surface 21iw, and therefore discharge from the substrate 12 to the heat sink 21. Can be suppressed.

  In the lighting apparatus 100, the groove portions 21d and 21d are formed such that the creepage distance Dx from the conductors (electrodes 12A and 12C and circuits 12Ac and 12Cc) provided on the substrate 12 to the inner surface 21iw is longer than a predetermined value. Has been. The “predetermined value” can be determined according to the applied voltage in the lightning surge test. For example, when the applied voltage is 4 kV, the creeping distance Dx can be 4 mm or more, and when the applied voltage is 6 kV, the creeping distance Dx can be 6 mm or more. This is a relationship in which the creepage distance Dx is increased by 1 mm every time the applied voltage increases by 1 kV, but the relationship between the applied voltage and the creepage distance Dx is an example.

  In the present embodiment, the outer surface 21ow is provided at a position that does not intersect with the substrate 12 of the attached light source body 11 when viewed in plan. That is, in the groove portions 21d and 21d, the outer surface 21ow constituting the groove portions 21d and 21d is formed on the outer side in the surface direction of the mounting surface 21A rather than the side surface 12s of the substrate 12.

  By setting it as such a shape, the board | substrate 12 will be fixed to the area | region in which groove part 21d * 21d was formed in a part of periphery. More specifically, since the groove portions 21d and 21d are formed following the shape of the substrate 12, the substrate 12 is fixed to an inner region where the groove portions 21d and 21d are formed in a part of the periphery. .

  As described above, in the groove portions 21d and 21d, the outer surface 21ow constituting the groove portions 21d and 21d is formed on the outer side in the surface direction of the mounting surface 21A rather than the side surface 12s of the substrate 12. Thereby, since this lighting fixture 100 can ensure the spatial distance Dy from the side surface 12s of the board | substrate 12 to the outer side surface 21ow, it becomes possible to suppress generation | occurrence | production of the discharge from the board | substrate 12 to the heat sink 21. FIG. More specifically, since the lighting fixture 100 can secure a spatial distance Dy from the side surface 12s of the substrate 12 to the corner portion formed by the mounting surface 21A and the outer surface 21ow, the discharge from the substrate 12 to the heat sink 21 is generated. Can be suppressed.

  In the lighting device 100, the groove portions 21d and 21d have a spatial distance Dy longer than a predetermined value from the side surface 12s of the substrate 12 to the outer surface 21ow (the corner portion formed by the mounting surface 21A and the outer surface 21ow). It is formed to become. The “predetermined value” can be determined according to the applied voltage in the lightning surge test. For example, when the applied voltage is 4 kV, the spatial distance Dy can be 4 mm or more, and when the applied voltage is 6 kV, the spatial distance Dy can be 6 mm or more. This is a relationship in which the spatial distance Dy is increased by 1 mm every time the applied voltage increases by 1 kV, but the relationship between the applied voltage and the spatial distance Dy is an example.

  Further, in the present embodiment, the bottom side surface 21 bw is provided in parallel to the substrate 12 of the attached light source body 11. That is, in the groove portions 21 d and 21 d, the bottom side surface 21 bw constituting the groove portions 21 d and 21 d is formed in parallel to the back surface 12 b of the substrate 12.

  By setting it as such a shape, the board | substrate 12 will be fixed in parallel with respect to the bottom side surface 21bw which comprises the groove parts 21d * 21d. More specifically, since the back surface 12b of the substrate 12 is formed flat, the substrate 12 is fixed in parallel to the bottom side surface 21bw constituting the groove portions 21d and 21d.

  Thus, the groove portions 21 d and 21 d are formed such that the bottom side surfaces 21 bw constituting the groove portions 21 d and 21 d are parallel to the back surface 12 b of the substrate 12. Thereby, since the spatial distance Dz from the back surface 12b of the board | substrate 12 to the bottom side surface 21bw becomes constant, this lighting fixture 100 can suppress generation | occurrence | production of the discharge from the board | substrate 12 to the heat sink 21. FIG. More specifically, the lighting fixture 100 suppresses the occurrence of discharge from the substrate 12 to the heat sink 21 because the spatial distance Dz from the back surface 12b to the bottom side surface 21bw of the substrate 12 does not change and electric field concentration does not occur. Is possible.

  That is, the luminaire 100 disclosed in the present application is a luminaire 100 including a light source body 11 including a light emitting element 13 on a surface of a substrate 12 and a heat sink 21 that dissipates heat of the light source body 11. The light source body 11 is attached to the heat sink 21 in a state where the back surface 12b of the substrate 12 is in contact, and the heat sink 21 has groove portions 21d and 21d formed at least in a portion overlapping the conductor in the substrate 12, and the groove portion 21d and 21d have bottom side surfaces 21bw forming the grooves 21d and 21d formed in parallel to the back surface 12b of the substrate 12, and the groove portions 21d and 21d extend from the back surface 12b of the substrate 12 to the bottom side surface 21bw. The spatial distance Dz is longer than the distance that can suppress the occurrence of leakage current due to lightning surge. That.

  In the lighting apparatus 100, the groove portions 21d and 21d are formed such that the spatial distance Dz from the back surface 12b to the bottom side surface 21bw of the substrate 12 is longer than a predetermined value. The “predetermined value” can be determined according to the applied voltage in the lightning surge test. For example, when the applied voltage is 4 kV, the spatial distance Dz can be 4 mm or more, and when the applied voltage is 6 kV, the spatial distance Dz can be 6 mm or more. This is a relationship in which the spatial distance Dz is increased by 1 mm every time the applied voltage increases by 1 kV, but the relationship between the applied voltage and the spatial distance Dz is an example.

  Next, other characteristic points of the lighting fixture 100 will be described.

  As described above, the present lighting fixture 100 is characterized in that the grooves 21d and 21d are locally provided in the portion overlapping the back surface 12b of the substrate 12. This is intended to suppress the occurrence of discharge from the substrate 12 to the heat sink 21. Then, the relative position and relative angle of the substrate 12 with respect to the grooves 21d and 21d, that is, the mounting position and mounting angle of the light source body 11 become important. For this reason, this luminaire 100 is provided with a plurality of protrusions 21P on the mounting surface 21A (see FIGS. 3, 4, and 5), so that the holder 4 can be mounted at a predetermined position and a predetermined angle.

  In the lighting fixture 100, the protrusion 21P is provided along the outer shape of the holder 4 attached at a predetermined position and a predetermined angle. Therefore, when the holder 4 is fixed so as to be in contact with all the protrusions 21P, the holder 4 is necessarily attached at a predetermined position and a predetermined angle. However, the arrangement and shape of the protrusions 21P are not limited. In addition, although this embodiment demonstrated the heat sink which can be used for a lighting fixture, a use is not restricted to a lighting fixture. The heat sink concerning this invention should just be able to dissipate the heat which the board | substrate with which the electrical component was mounted is attached, and an electrical component or a board | substrate generate | occur | produces.

DESCRIPTION OF SYMBOLS 100 Lighting fixture 1 Light source part 11 Light source body 12 Board | substrate 12b Back surface 12s Side surface 12A Electrode 12Ac Circuit 12C Electrode 12Cc Circuit 13 Light emitting element 2 Main body part 21 Heat sink 21d Groove part 21iw Inner side surface 21ow Outer side surface 21bw Bottom side surface 3 Power supply part 31 Power supply unit 31 Dx Creepage distance Dy Spatial distance Dz Spatial distance

Claims (4)

A lighting apparatus comprising: a light source body provided with a light emitting element on a surface of a substrate; and a heat sink that dissipates heat of the light source body,
The light source body is attached to the heat sink in a state where the back surface of the substrate is in contact,
In the heat sink, a groove is formed in a portion overlapping at least the conductor in the substrate ,
The groove part has an outer surface that forms the groove part formed outside the side surface of the substrate .
A lighting apparatus characterized by that. The groove is formed such that a spatial distance from a side surface of the substrate to the outer surface is longer than a distance that can suppress generation of a leakage current due to a lightning surge .
The lighting fixture according to claim 1. A lighting apparatus comprising: a light source body provided with a light emitting element on a surface of a substrate; and a heat sink that dissipates heat of the light source body,
The light source body is attached to the heat sink in a state where the back surface of the substrate is in contact,
In the heat sink, a groove is formed in a portion overlapping at least the conductor in the substrate,
The groove portion is formed such that an inner side surface constituting the groove portion is formed on an inner side than a side surface of the substrate,
The groove is formed such that a creepage distance from the conductor provided on the substrate to the inner surface is longer than a distance that can suppress generation of a leakage current due to a lightning surge.
A lighting apparatus characterized by that. A heat sink to which a board on which electrical components are mounted is attached,
Having a mounting surface to which the substrate is mounted;
In the mounting surface, a groove is formed in a portion overlapping at least the conductor in the substrate,
The groove part has an outer surface that forms the groove part formed outside the side surface of the substrate.
A heat sink characterized by that.

Images