JP2009245643A - Lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system capable of efficiently dissipating heat generated by a light emitting element. <P>SOLUTION: This lighting system 1 includes an LED package 20 having an LED chip 22 and electrodes 24, 25 electrically connected to the LED chip 22, a circuit board 6 having a connection part to be connected to the electrodes 24, 25, and a wiring pattern connected to the connection part on the same side, and a chassis 11a having a heat dissipating sheet 10a on its surface. The LED package 20 is disposed on the chassis 11a through the heat dissipating sheet 10a, and the circuit board 6 and the chassis 11a are disposed so that the board surface 6a on which the connection part in the circuit board 6 faces the surface on which the LED package 20 is disposed each other in the chassis 11a, and at least a part of the wiring pattern 7 is brought into contact with the heat dissipating sheet 10a on the chassis 11a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lighting device that efficiently dissipates heat generated by a light emitting element.

  In recent years, lighting devices using LED (Light Emitting Diode) chips as light sources have been developed, and high output of LED chips has been achieved.

  In addition, since it is possible to manufacture LEDs of three primary colors of blue, red, and green, development of forming a white light source by combining these three primary colors of LEDs has been performed. As another configuration for forming a white light source, white light is generated by combining an LED and a phosphor that is excited by light emitted from the LED and emits light having a wavelength different from that of the emitted light. A method has also been developed. For example, a white light emitting device that generates white light by combining a LED chip that emits blue light or ultraviolet light and a phosphor has been commercialized. These white light sources formed by LEDs have started to be used for lighting applications as substitutes for light bulbs and fluorescent lamps and for light sources of pack lights for liquid crystal displays, in accordance with recent increases in output.

  This LED chip has a characteristic that, when the junction temperature becomes high, the conversion efficiency for converting electric energy into light output decreases. For this reason, in order to obtain high conversion efficiency in the LED chip, it is necessary to efficiently release (heat radiation) the heat generated in the light emitting portion of the LED chip to the outside.

  Here, several conventional techniques for dissipating the heat of the LED chip are known. For example, in Patent Documents 1 to 4, by disposing an LED chip and an electrode of the LED chip on a chassis made of metal via an insulating heat conductive sheet, heat from the LED chip is thermally conducted. A configuration is disclosed in which heat is conducted to the chassis through the sheet and heat is released from the chassis.

  The configurations disclosed in Patent Documents 1 to 4 will be described in more detail below with reference to FIG. FIG. 9 is a cross-sectional view illustrating a heat dissipation structure of the illumination device 100 disclosed in Patent Documents 1 to 4. As illustrated in FIG.

  As shown in FIG. 9, the lighting device 100 includes an LED package 120, a circuit board 106, a heat conductive sheet 110 having insulation properties, and a chassis 111 made of metal. The LED package 120 includes a protective cover 121, an LED chip 122, wiring 123, and electrodes 124 and 125. Further, the LED package 120 is disposed on a chassis 111 made of metal via a heat conductive sheet 110 having insulation properties. The electrodes 124 and 125 of the LED package 120 are electrically connected to the wiring pattern 107 wired on the circuit board 106 based on glass epoxy by soldering 108 and 109. .

As shown in FIG. 9, the LED package 120 is disposed on the chassis 111 via the heat conductive sheet 110, whereby the heat generated by the LED chip 122 is transmitted to the electrodes 124 and 125, and the heat conduction is further performed. It is transmitted to the chassis 111 via the sheet 110 and is radiated by the chassis 111.
JP 2007-059371 A (published March 8, 2007) JP 2007-165937 A (released on June 28, 2007) JP 2007-43126 A (published February 15, 2007) JP 2007-43125 A (published February 15, 2007)

  However, the conventional illumination device shown in FIG. 9 has the following problems. That is, the heat generated by the LED chip 122 is transmitted to the electrodes 124 and 125 and further to the chassis 111 via the heat dissipation sheet 110, but not all heat is conducted through this path. That is, the heat generated by the LED chip 122 is transmitted to the electrodes 124 and 125 and is also conducted to the wiring pattern 107 through the solders 108 and 109. Although heat is directly radiated to the air through the protective cover 121, the amount of heat is small, and most of the heat generated by the LED chip 122 is generated between the path to the chassis 111 and the path to the wiring pattern 107. Conducts in two paths.

  Each amount of heat conducted to each of the two paths is determined by the thermal conductivity between the heat radiation sheet 110 and the solders 108 and 109, and the distance (thickness) from the heat source. Here, since the heat dissipation sheet 110 is employed for the purpose of heat dissipation, it is a sheet having good thermal conductivity, but its thermal conductivity is about 10 [W / mK] or less, and the thermal conductivity is low. Compared to the solders 108 and 109 which are about 70 to 80 [W / mk].

  In addition, the distance from the heat source is shorter than the solders 108 and 109 in the heat radiation sheet 110 immediately below the LED chip 122 that is the heat source. However, in view of the difference in thermal conductivity between the heat radiation sheet 110 and the solders 108 and 109, it can be seen that a considerable amount of heat generated by the LED chip 122 is conducted to the wiring pattern 107 via the solders 108 and 109. .

  At this time, the heat conducted to the wiring pattern 107 is hardly conducted to the glass epoxy which is the base material of the substrate 106. This is because the thermal conductivity of glass epoxy is about 1 [W / mK], which is lower than the thermal conductivity of the heat dissipation sheet 110. In general, the wiring pattern 107 is made of copper, and the heat of copper This is because the conductivity is about 400 [W / mK], which is much higher than that of a crow epoxy. For this reason, the heat conducted to the wiring pattern 107 is not transferred to the circuit board but is radiated from the wiring pattern 107 to the air.

  Here, as shown in FIG. 9, in the illumination device 100 of the conventional technique, the wiring pattern 107 is arranged on the circuit board 106 on the substrate surface 106 a on the light irradiation direction side from the LED package 120. In general, in a lighting device, a sheet with high reflectance (hereinafter referred to as a reflective sheet) is provided on the substrate surface 106a for the purpose of improving the utilization efficiency of light emitted from the LED package 120. Generally, this reflective sheet is made of a resin such as polycarbonate, but its thermal conductivity is a very small value of 1 [W / mk] or less. Therefore, the heat conducted to the wiring pattern 107 is not conducted to the reflection sheet or the circuit board 106, and the temperature of the wiring pattern 107 itself rises. As a result, as the temperature of the wiring pattern 107 increases, the temperature of the LED chip 122 in the LED package 100 increases. That is, the conversion efficiency for converting the electrical energy into the light output in the LED chip 122 is lowered.

  In addition, when the lighting device 100 of the related art shown in FIG. 9 is used for lighting as an alternative to a light bulb or a fluorescent lamp, a reflector (reflector) is installed around the LED package 120 and emitted from the LED package 120. The light distribution characteristic of the light to be controlled is controlled to obtain a desired characteristic. Here, since this reflector (reflector) is often made of resin, the situation is similar to the case where the above-described reflector sheet is installed, and as a result, the conversion efficiency of the LED chip 122 is lowered. Furthermore, when the resin reflector is in contact with the wiring pattern 107, it is conceivable that the resin constituting the reflector is discolored or deformed due to the wiring pattern 107 becoming hot.

  Further, in the prior art lighting device 100 shown in FIG. 9, even when no reflection sheet or reflector is installed, the wiring pattern 107 side is a side to which light is irradiated. It is difficult to attach a heat radiating member such as a heat radiating fin. This is because if the heat radiation member is attached to the wiring pattern 107, the light emitted from the LED package 120 is blocked. For this reason, the wiring pattern 107 that is not in contact with the heat dissipation member cannot sufficiently dissipate the heat conducted from the LED chip 122 to the air.

  That is, in order to sufficiently dissipate the heat generated by the LED chip 122, it is essential to transmit this heat to the chassis 111 having a large surface area. However, the configuration of the conventional lighting device 100 is generated by the LED chip 122. As a result, the LED chip 122 has a problem that high conversion efficiency is not obtained.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a lighting device capable of more efficiently dissipating heat generated by a light emitting element. .

In order to solve the above problems, the lighting device according to the present invention
A circuit board having a light emitting unit having a light emitting element and an electrode electrically connected to the light emitting element, a connecting portion connected to the electrode, and a wiring pattern connected to the connecting portion on the same surface And a heat radiating member having an insulating material on the surface, the light emitting unit is disposed on the heat radiating member via the insulating material, and the connection portion on the circuit board is disposed. And the surface of the heat dissipation member on which the luminous body unit is disposed are opposed to each other, and at least a part of the wiring pattern is in contact with the insulating material on the heat dissipation member. It is characterized by.

  According to the above configuration, the heat generated by the light emitting element is conducted to the electrode of the light emitter unit. Further, the heat conducted to the electrode is conducted to the wiring pattern through the connection portion, and is also conducted from the electrode directly to the heat radiating member through the insulating material.

  Here, in the lighting device of the present invention, the surface of the circuit board on which the connection portion is disposed and the surface of the heat dissipation member on which the light emitting unit is disposed are opposed to each other and at least one of the wiring patterns. The portion is in contact with the insulating material on the heat dissipation member. Therefore, the heat conducted to the wiring pattern is conducted to the heat radiating member through the insulating material. In other words, in the lighting device according to the present invention, not only the path in which the heat generated by the light emitting element is conducted directly from the electrode to the heat radiating member through the insulating material, but also the heat conducted to the wiring pattern is conducted to the heat radiating member. Will have two paths. Thereby, the heat generated by the light emitting element is efficiently conducted to the heat radiating member through these two paths, and as a result, the heat radiating member efficiently radiates heat into the air.

  As described above, the illuminating device of the present invention has an effect that the heat generated by the light emitting element can be radiated more efficiently.

In the lighting device according to the present invention,
The light emitting element is preferably a light emitting diode.

  According to the above configuration, the lighting device uses, as a light emitting element, a light emitting diode having excellent characteristics such as long life and low power consumption as compared with a light emitting element such as a light bulb or a fluorescent lamp. Therefore, the lighting device of the present invention having the above-described configuration has an effect of having a long life and low power consumption.

In the lighting device according to the present invention,
It is preferable that the wiring pattern is disposed only on the surface of the circuit board having the connection portion.

  With the above configuration, the wiring pattern is not arranged on the surface of the circuit board opposite to the surface having the connection portion (hereinafter referred to as the opposite surface of the circuit board). Furthermore, a material having low thermal conductivity such as glass epoxy is generally used for the base material of the circuit board. For this reason, the heat conducted to the wiring pattern is not easily conducted to the opposite surface of the circuit board, but is conducted to the heat radiating member through the insulating material. Therefore, even if a resin member having low thermal conductivity is disposed on the opposite surface of the circuit board, for example, a reflector or a reflector sheet for controlling the light distribution characteristics of the emitted light from the light emitter unit, It does not affect the heat dissipation of the device. Furthermore, even if the resin member is made of a resin having a low heat resistance temperature, the heat generated by the light emitting element is difficult to conduct on the opposite surface of the circuit board. Therefore, there is no deformation or discoloration.

  As described above, by providing the above configuration, the lighting device of the present invention can dispose the resin member on the opposite surface of the circuit board without affecting the heat dissipation efficiency of the lighting device.

In the lighting device according to the present invention,
The wiring pattern is arranged on both surfaces of the circuit board, and the area of the wiring pattern arranged on the surface having the connection portion in the circuit board is a surface opposite to the surface having the connection portion. It is preferable that it is larger than the area of the wiring pattern arrange | positioned in this.

  With the above configuration, the heat conducted from the light emitting element to the wiring pattern is more conducted to the surface having the connection portion in the circuit board than to the opposite surface of the circuit board. That is, most of the heat conducted to the wiring pattern is conducted to the heat radiating member through the insulating material. Therefore, even if a resin member having low thermal conductivity is disposed on the opposite surface of the circuit board, for example, a reflector or a reflector sheet for controlling the light distribution characteristics of the emitted light from the light emitter unit, It can suppress that the thermal radiation efficiency of an apparatus falls.

In the lighting device according to the present invention,
Both the heat dissipation member and the circuit board have screw holes for inserting screws, and the circuit board is preferably fixed to the heat dissipation member with the screws.

  With the above-described configuration, pressure is applied to the heat radiating member and the circuit board by the screws in a direction facing each other. An insulating material is disposed between the heat dissipation member and the circuit board. For this reason, the heat radiation member and the circuit board are fixed by screws, so that the degree of adhesion between the circuit board and the insulating material is increased, and the contact area between the wiring pattern on the circuit board and the insulating material is increased. . As a result, the heat conducted from the light emitting element to the wiring pattern is efficiently conducted by the heat radiating member through the insulating material. That is, the lighting device of the present invention has an effect that heat generated by the light emitting element can be radiated more efficiently.

Moreover, the illumination device according to the present invention further includes:
In the heat radiating member, it is preferable that a region where the light emitting unit is disposed is recessed.

  By providing the said structure, the surface area of a heat radiating member becomes large compared with the case where a heat radiating member does not have a hollow. Thereby, the quantity of heat dissipated by the heat radiating member is increased, and as a result, the heat radiating characteristics of the lighting device of the present invention are improved.

In the lighting device according to the present invention,
It is preferable that the heat radiating member has at least one convex portion on a surface opposite to a surface on which the light emitting unit is disposed.

  By providing the said structure, the surface area of a heat radiating member becomes large compared with the case where a heat radiating member does not have a convex part. Thereby, the quantity of heat dissipated by the heat radiating member is increased, and as a result, the heat radiating characteristics of the lighting device of the present invention are improved.

  Furthermore, by providing the said structure, the intensity | strength with respect to the bending stress of a heat radiating member increases, As a result, there exists an effect that the intensity | strength of the illuminating device of this invention increases.

Moreover, the illumination device according to the present invention further includes:
It is preferable that an optical element for changing the light distribution characteristic of the light emitted from the light emitting element is further provided, and the optical element is disposed so as to cover the light emitting element disposed on the heat dissipation member.

  By providing the optical element as in the above configuration, the illumination device of the present invention can change the light distribution characteristic of the emitted light emitted from the light emitting element to a desired light distribution characteristic by the optical element. The light having desired light distribution characteristics can be irradiated to the outside.

In the lighting device according to the present invention,
The optical element preferably diffuses or condenses the emitted light by transmitting or reflecting the emitted light from the light emitting element.

  According to the above configuration, the optical element can diffuse or condense the emitted light by transmitting or reflecting the emitted light from the light emitting element. That is, the optical element can change the light distribution characteristic of the light emitted from the light emitting element. Thereby, the illuminating device of this invention can change the light distribution characteristic of the emitted light which a light emitting element emits into a desired light distribution characteristic, and, as a result, irradiates the light which becomes a desired light distribution characteristic outside be able to.

In the lighting device according to the present invention,
It is preferable that the optical element includes a protrusion at a contact point with the circuit board, and the circuit board includes an insertion hole for inserting the protrusion.

  According to the above configuration, when the optical element is disposed on the circuit board, the optical element can be disposed at a desired position on the circuit board simply by inserting the protrusion into the insertion hole. Therefore, when manufacturing the illumination device of the present invention, the work in the step of arranging the optical element on the circuit board can be simplified.

  As described above, the lighting device of the present invention includes a light emitting unit having a light emitting element and an electrode electrically connected to the light emitting element, a connection portion connected to the electrode, and a connection portion connected to the connection portion. A circuit board having a wiring pattern on the same surface, and a heat radiating member having an insulating material on the surface, and the light emitter unit is disposed on the heat radiating member via the insulating material. The circuit board and the heat dissipating member are disposed such that the surface of the circuit board on which the connecting portion is disposed and the surface of the heat dissipating member on which the light emitter unit is disposed are opposed to each other. In addition, at least a part of the wiring pattern is in contact with the insulating material on the heat dissipation member.

  Therefore, the illuminating device of the present invention can provide an illuminating device that can more efficiently dissipate heat generated by the light emitting element.

  Embodiments according to the present invention will be described below with reference to the drawings.

Embodiment 1
Embodiment 1 of the present invention will be described below with reference to FIG. FIG. 1 is a cross-sectional view showing a heat dissipation structure of the lighting device 1a according to this embodiment. The present invention aims to efficiently dissipate heat generated by the LED chip 22 serving as a light source. Therefore, in FIG. 1, only the configuration in the vicinity of the LED package 20 is illustrated in order to show the heat dissipation structure in the lighting device 1, and other configurations such as a power supply unit that supplies power to the other LED package 20 are illustrated. Omitted.

  First, as shown in FIG. 1, the lighting device 1a includes an LED package 20 (light emitting unit), a circuit board 6 having a wiring pattern 7, a heat radiating sheet 10a (insulating material) having insulating and high thermal conductivity, and A chassis 11a (heat dissipating member) made of metal is provided. The LED package 20 includes a protective cover 21, an LED chip 22 (light emitting element), wiring 23, and electrodes 24 and 25. Further, the LED package 20 is disposed on a chassis 11a made of metal via a heat conductive sheet 10a having insulation properties. In addition, the circuit board 6 in this embodiment is the structure which has the wiring pattern 7 in the board | substrate surface 6a.

  Here, the wiring pattern 7 has an electrode pattern (connection portion) for electrically connecting to the electrodes 24 and 25 via the solders 8 and 9. More specifically, the wiring pattern 7 is composed of a copper foil, and an electrode pattern (a region where the copper foil is covered with a resist and a region where the copper foil not applied with the resist is exposed) Connecting portion).

  The circuit board 6 and the chassis 11a are arranged so that the board surface 6a on which the electrode pattern is arranged on the circuit board 6 and the surface on which the LED package 20 is arranged on the chassis 11a face each other. Furthermore, at least a part of the wiring pattern 7 is in contact with the heat dissipation sheet 10a on the chassis 11a.

  The circuit board 6 also has LED through holes 5 for the purpose of inserting the LED package 20. The LED package 20 is inserted into the LED through-hole 5 from the board surface 6a side of the circuit board 6 to the board surface 6b side, so that the LED package 20 is directed toward the circuit board 6 as viewed from the chassis 11a, in other words, upward in FIG. Furthermore, the light emitted from the LED chip 22 can be emitted.

  The protective cover 21 provided in the LED package 20 is a cover for protecting the LED chip 22, but the protective cover 22 changes the light distribution characteristics of the emitted light from the LED chip 22, such as a lens. It may have optical properties.

  The electrode pattern which is a part of the wiring pattern 7 and the electrodes 24 and 25 are electrically connected by solders 8 and 9. More specifically, when the LED package 20 is mounted on the circuit board 6, a reflow process is performed in which cream solder is applied to the electrode pattern of the wiring pattern 7 or the electrodes 24 and 25 to increase the ambient temperature. Thus, the wiring pattern 7 and the electrodes 24 and 25 are electrically connected.

  The heat dissipation sheet 10a installed between the wiring pattern 7 on the circuit board 6 and the chassis 11a has electrical insulation and high-efficiency thermal conductivity. As a result, even if the heat generated by the LED chip 22 is conducted to the wiring pattern 7 via the electrodes 24 and 25, the heat conducted to the wiring pattern 7 is conducted to the chassis 11a via the heat radiation sheet 10a. Heat is dissipated by 11a.

  Moreover, it is preferable that the thermal radiation sheet 10a is comprised with the material which has elasticity. Due to the elasticity of the heat dissipation sheet 10a, the adhesion between the electrode 24, the electrode 25, and the wiring pattern 7 and the heat dissipation sheet 10a is increased, and heat from the electrode 24, the electrode 25, and the wiring pattern 7 to the heat dissipation sheet 10a is increased. Conduction is performed with high efficiency.

  Furthermore, the heat dissipation sheet 10a has a sufficiently larger area on the chassis 11a than the area occupied by the LED package 20. As described above, the heat generated by the LED chip 22 is also conducted to the wiring pattern 7 via the electrodes 24 and 25. Accordingly, by making the area occupied by the heat dissipation sheet 10a in the chassis 11a sufficiently larger than the area occupied by the LED package 1 (for example, an area that is 10 times or more the area indicated by the LED package 20), the heat dissipation sheet 10a. The heat conducted not only to the electrodes 24 and 25 but also to the wiring pattern 7 can be released to the chassis 11a. As described above, the heat radiation sheet 10a is made of an elastic material and is sufficiently larger than the size of the LED package 20, whereby the heat generated by the LED chip 2 is efficiently conducted to the chassis 11a, and the chassis 11a. The heat is dissipated.

  As described above, in the lighting device 1a according to the present embodiment, the heat generated by the LED chip 22 is transmitted through the electrodes 24 and 25 to the heat dissipation sheet 10a and the electrodes 24 and 24. It is transmitted to the chassis 11a through two paths: a path that conducts to the wiring pattern 7 and a path that conducts from the wiring pattern 7 to the heat dissipation sheet 10a. Therefore, there is no problem in the prior art that heat conducted to the wiring pattern 7 cannot be radiated. As a result, in the lighting device 1a, the heat generated by the LED chip 22 is efficiently transmitted to the chassis 11a and is dissipated by the chassis 11a, so that an increase in the junction temperature of the LED chip 22 can be prevented. Play. Furthermore, preventing the increase in the junction temperature of the LED chip 22 improves the light conversion efficiency of the LED chip 22, and as a result, contributes to a reduction in power consumption of the lighting device 1a.

  Moreover, in this embodiment, the board surface 6b of the circuit board 6 is a glass epoxy with low thermal conductivity, and even if a reflective sheet or a reflective plate is provided on the board surface 6b, the heat generated by the LED chip 22 It has no effect on heat dissipation.

  Further, in the present embodiment, the circuit board 6 is a single-sided board having the wiring pattern 7 only on one side (the board side 6a). Therefore, the cost is low and the heat radiation performance is high as compared with the case of using a double-sided board or a multilayer board. It becomes a lighting device.

  In the present embodiment, the circuit board 6 has the wiring pattern 7 on the board surface 6a. However, the present invention is not limited to this, and the circuit board 6 is not limited to the board surface 6a. The substrate pattern 6b on the side opposite to the substrate surface 6a in FIG. Also in this case, the heat conducted from the LED chip 22 to the wiring pattern 7 is conducted to the chassis 11a via the heat radiation sheet 10a. Therefore, the same heat radiation performance as when the wiring pattern 7 is provided only on the substrate surface 6a. Will have.

  When wiring patterns 7 are arranged on both sides of the circuit board, specifically, both the board surface 6a and the board surface 6b, the area of the wiring pattern 7 arranged on the board surface 6a side It is preferable to make it larger than the area of the wiring pattern 7 arranged on the surface 6b side. Specifically, by making the area of the wiring pattern 7 on the substrate surface 6a side larger than the area of the wiring pattern 7 on the substrate surface 6b side, the heat from the light emitting element is higher than that on the substrate surface 6b side. As a result, most of the heat conducted to the wiring pattern 7 is conducted to the chassis 11a and is radiated by the chassis 11a.

  Furthermore, in the present embodiment, the size of the heat dissipation sheet 10a is sufficiently large. However, the size of the heat dissipation sheet 10a may be the same size as the circuit board 6 and may be in contact with the entire surface of the circuit board 6a.

  In this embodiment, an LED chip is used as a light source. However, the present invention is not limited to this, and the lighting device of the present invention can be used as long as it is a light emitting element having a function of converting electrical energy into light output. You may apply as a provided light source.

  Hereinafter, the configuration shown in the second to sixth embodiments is a modification of the first embodiment. In the following second to sixth embodiments, different parts from the first embodiment will be described, and the same functions and operations will be shown. About the member, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

[Embodiment 2]
A second embodiment of the present invention will be described below with reference to FIG. FIG. 2 is a cross-sectional view illustrating a heat dissipation structure of the lighting device 1b according to the present embodiment.

  The illumination device 1b shown in FIG. 2 is different from the illumination device 1a of Embodiment 1 in that the shape of the chassis 11b is different from the shape of the chassis 11a. Specifically, as shown in FIG. 2, the chassis 11b included in the lighting device 1b has a recessed region in which the LED package 20 is disposed. Thus, when the chassis 11b has the depression, the surface area of the chassis 11b increases, and thereby, the amount of heat to be radiated increases as compared with the chassis 11a (see FIG. 1) that does not have the depression. As a result, the lighting device 1b has an effect that the heat generated by the LED chip 22 can be radiated more efficiently by providing the chassis 11b with the depression.

  Further, as shown in FIG. 2, the chassis 11b has a shape in which a surface opposite to the surface on which the LED package 20 is disposed protrudes, in other words, a convex portion on the surface opposite to the surface on which the LED package 20 is disposed. have. Thus, when the chassis 11b has the convex portion, the surface area of the chassis 11b increases, and as a result, the same effect as in the case of having the depression is produced. Furthermore, when the chassis 11b has the convex portion, there is an additional effect that the strength against the bending stress of the lighting device 1b is increased.

  In the present embodiment, the chassis 11b has a configuration having one convex portion, but the present invention is not limited to this, and the chassis 11b may have a plurality of convex portions.

[Embodiment 3]
Embodiment 3 of the present invention will be described below with reference to FIG. FIG. 3 is a cross-sectional view showing the heat dissipation structure of the lighting device 1c according to this embodiment.

  The illumination device 1c shown in FIG. 3 is different from the illumination device 1a of the first embodiment in that the circuit board 6 is fixed to the chassis 11c with screws 12. Specifically, as shown in FIG. 3, the circuit board 6 and the chassis 11 c have screw holes for inserting the screws 12. By inserting the screws 12 into the screw holes, the circuit board 6 is inserted. 6 is fixed to the chassis 11c.

  Thus, the circuit board 6 and the chassis 11c are fixed to the circuit board 6 by the screws 12, in other words, the circuit board 6 and the chassis 11c are applied with pressure in a direction opposite to each other. In the heat-dissipating sheet 10c sandwiched between 11c, the degree of adhesion of the circuit board 6 to the wiring pattern 7 and the chassis 11c is increased. As a result, the contact area between the heat dissipation sheet 10c and the electrode 24, the electrode 25, and the wiring pattern 7 is increased, and as a result, the thermal resistance from the electrode 24, the electrode 25, and the wiring pattern 7 to the heat dissipation sheet 10c is reduced. Accordingly, heat is more efficiently conducted from the LED chip 22 to the heat dissipation sheet 10c. Furthermore, since the contact area between the heat radiation sheet 10c and the chassis 11c is also increased, the thermal resistance from the heat radiation sheet 10c to the chassis 11c is reduced, and as a result, heat is more efficiently conducted from the heat radiation sheet 10c to the chassis 11c. Will do.

  From the above, the lighting device 1c fixes the circuit board 6 to the chassis 11c using the screws 12, whereby the heat generated by the LED chip 22 is efficiently conducted by the chassis 11c. As a result, in the LED chip 2, There exists an effect that it can prevent that the conversion efficiency which converts electrical energy into light output falls.

  In the present embodiment, the circuit board 6 is fixed to the chassis 11c using two screws for one LED package 20, but the present invention is not limited to this, and the lighting device 1c The number of screws may be changed as appropriate according to the specifications.

[Embodiment 4]
Embodiment 4 of the present invention will be described below with reference to FIG. FIG. 4 is a cross-sectional view showing a heat dissipation structure of the lighting device 1d according to the present embodiment.

  The illumination device 1d shown in FIG. 4 is different from the illumination device 1a of the first embodiment in that a heat sink 13 is attached to the chassis 11a. Specifically, as shown in FIG. 4, the heat sink 13 is attached to the surface of the chassis 11a opposite to the surface on which the LED package 20 is disposed. The heat sink 13 is made of a material having a high thermal conductivity such as a metal, and has irregularities on the surface other than the surface in contact with the chassis 11a. By attaching the heat sink 13 made of a material having high thermal conductivity to the chassis 11a, the heat generated by the LED is conducted to the chassis 11a and then efficiently conducted from the chassis 11a to the heat sink 13. Further, since the heat sink 13 has irregularities on the surface, the surface area of the heat sink 13 is increased, and thereby the amount of heat radiated from the heat sink 13 is further increased.

  As described above, the lighting device 1d has the effect that the heat generated by the LED chip 22 can be radiated more efficiently by attaching the heat sink 13 to the chassis 11a.

[Embodiment 5]
Embodiment 5 of the present invention will be described below with reference to FIGS. In addition, the illuminating device 1e shown in Embodiment 5 is a modification of the illuminating device 1c shown in Embodiment 3, and in the following Embodiment 5, a different part from said Embodiment 3 is demonstrated, and the same function is demonstrated. The members having the same function are designated by the same reference numerals and the description thereof is omitted.

  First, the illumination device 1e shown in the present embodiment is different from the illumination device 1c of the third embodiment in that the illumination device 1e includes a lens optical element 14 that converts light emitted from the LED package 20 into desired light distribution characteristics. It is.

  With reference to FIG. 5, the schematic structure of the illuminating device 1e provided with five light sources is demonstrated. FIG. 5 is a schematic view of the illumination device 1e according to the present embodiment as seen from the side irradiated with light from the illumination device 1e.

  As shown in FIG. 5, five lens optical elements 14 are arranged on the circuit board 6. An LED package 20 is disposed inside each lens optical element 14. Here, the lens optical element 14 diffuses or condenses the light emitted from the LED package 20 to make the light emitted from the lighting device 1e have a desired light distribution characteristic. In FIG. 5, two screws 12 for fixing the circuit board 6 to the chassis 11 c (not shown in FIG. 5) are used for each LED package 20.

  Next, with reference to FIG. 6, the detailed arrangement configuration of the lens optical element 14 in the illumination device 1e will be described. 6 is a cross-sectional view taken along line A-A ′ shown in FIG. 5.

  As shown in FIG. 6, the lens optical element 14 has a hemispherical shape, and is further disposed so as to cover the LED package 20 disposed on the chassis 11c. Thereby, the lens optical element 14 converts the emitted light from the LED package 20 inside itself into a desired light distribution characteristic by diffusing or condensing the light, and irradiates light upward in the drawing.

  The lens optical element 14 is provided with a pin 14a (protrusion) for fixing to the circuit board 6, while the circuit board 6 is provided with a fixing hole (insertion hole) for inserting the pin 14a. ing. The pin 14 a is inserted into the insertion hole provided in the circuit board 6, and the lens optical element 14 is fixed to the circuit board 6 by the pin 14 a being welded or bonded by an adhesive.

  The lens optical element 14 is made of a resin having excellent optical characteristics such as polymethyl methacrylate resin (hereinafter referred to as PMMA) and polycarbonate (hereinafter referred to as PC). PMMA and PC are resins having excellent transparency and are generally used as optical elements such as lenses. This resin lens has an advantage that it can be manufactured at a lower cost than a glass lens. However, these resins have a lower heat resistant temperature than glass. For example, in a PMMA having a relatively high heat resistant temperature, the heat resistant temperature is about 150 ° C., and in PMMA whose heat resistant performance is generally inferior to that of PC, The heat resistant temperature is about 100 ° C. In order for the lens optical element 14 to obtain desired optical characteristics, the lens optical element 14 needs to be used in an environment of the above-described heat resistant temperature or less.

  Here, in the illuminating device 1e of this embodiment shown in FIG. 5, the wiring pattern 7 is arrange | positioned on the board | substrate surface 6a of the circuit board 6, and this wiring pattern 7 is in contact with the thermal radiation sheet | seat 10. FIG. The lens optical element 14 is installed on the substrate surface 6 b opposite to the substrate surface 6 a of the circuit substrate 6. Further, in the present embodiment, since the wiring pattern 7 does not exist on the substrate surface 6b of the circuit board 6, the lens optical element 14 is directly on the circuit board 6, in other words, on the glass epoxy constituting the circuit board 6. Will be installed. As described above, since this glass epoxy has an extremely low thermal conductivity than the copper foil used for the wiring pattern 7, the heat generated by the LED chip 22 is applied to the wiring pattern 7 on the substrate surface 6a side. Even if it conducts, it hardly conducts to the substrate surface 6b side. For this reason, even if the temperature of the wiring pattern 7 is equal to or higher than the heat resistance temperature of the lens optical element 14, the heat of the wiring pattern 7 is not conducted on the substrate surface 6b side, and the temperature of the lens optical element 14 is Never exceed the heat-resistant temperature. That is, in the illumination device 1e, even if the lens optical element 14 is made of a resin having a low heat-resistant temperature, the optical characteristics of the lens optical element 14 are not changed by the heat generated by the LED chip 22.

  Next, the shape of the wiring pattern 7 included in the circuit board 6 will be described below with reference to FIG. FIG. 7 is a schematic diagram showing a configuration of the circuit board 6 provided in the lighting device 1e of the present embodiment, and more specifically, a schematic diagram showing a board surface 6a (see FIG. 6) of the circuit board 6 having the wiring pattern 7. FIG.

  As shown in FIG. 7, the circuit board 6 has LED through holes 5 through which the LED packages 20 are inserted, wiring patterns 7, fixing holes 76 and 77 into which the pins 14 a of the lens optical element 14 are inserted, and screws 12. Screw holes 78 and 79 are provided for insertion. The wiring pattern 7 includes an electrode pattern 75 (connection portion) electrically connected to the electrode 24 (see FIG. 6), a wiring pattern 74 connected to the electrode pattern 75, and the electrode 25 (see FIG. 6). The electrode pattern 73 (connection part) to be electrically connected and the wiring pattern 72 connected to the electrode pattern 73 are configured.

  Here, the size of the LED through hole 5 is the portion of the LED package 20 excluding the electrodes 24 and 25, in other words, the projected area of the protective cover 21 (perpendicular to the circuit board 6 from above in FIG. 6). Larger than the projected area when projected onto the screen. Therefore, when the LED package 20 is mounted on the circuit board 6, a gap is generated between the edge of the LED through hole 5 in the circuit board 6 and the protective cover 21 provided in the LED package 20. Thereby, air can enter and exit from the LED through hole 5 into the lens optical element 14.

  Thus, since air can enter and exit from the LED through hole 5, the LED package 20 is not sealed by the lens optical element 14. That is, in the lens optical element 14, the air heated by the LED package 20 can go out from the LED through hole 5. As a result, the illuminating device 1e can suppress the temperature rise of the air in the lens optical element 14, and has the effect of suppressing the temperature rise of the LED chip 22.

  The wiring pattern 7 is made of copper foil. In the wiring pattern 7, the region whose surface is insulated by the resist corresponds to the wiring patterns 72 and 74, and the region whose surface is not insulated by the resist. This corresponds to the electrode patterns 73 and 75. By mounting the electrodes 24 and 25 of the LED package 20 on the electrode patterns 73 and 75, the LED package 20 and the wiring pattern 7 are electrically connected. The wiring patterns 72 and 74 are not installed around the fixing holes 76 and 77.

  The circuit board 6 has screw holes 78 and 79. By inserting the screws 12 into the screw holes 78 and 79, the circuit board 6 has the heat dissipation sheet 10c as shown in FIG. Via the chassis 11c. Thus, by fixing the circuit board 6, the heat radiation sheet 10c, and the chassis 11c to each other with the screws 12, the degree of close contact with each other increases, and as a result, in the lighting device 1e, the heat generated by the LED chip 22 is more efficient. Can dissipate heat well.

  As described above, in the lighting device 1e according to the present embodiment, the heat generated by the LED chip 22 is conducted to the electrodes 24 and 25, and then is conducted to the chassis 11c via the heat dissipation sheet 10c, and the solder 8 and 9 is efficiently conducted to the chassis 11c through both paths from the wiring pattern 7 to the chassis 11c through the heat radiation sheet 10c. As a result, there is no problem with the prior art that the heat transmitted to the wiring pattern 7 of the circuit board 6 cannot be dissipated. As a result, the illuminating device 1e has the effect that the rise in the junction temperature in the LED chip 22 can be further suppressed.

  Further, since the LED through hole 5 provided in the circuit board 6 is larger than the projected area of the protective cover 21 of the LED package 20, the air in the lens optical element 14 passes through the gap between the edge of the LED through hole 5 and the protective cover 21. Can go in and out. Thereby, the upper side of the temperature of the air inside the lens optical element 14 is suppressed, and as a result, the lighting device 1e has an effect of further suppressing the increase in the junction temperature of the LED chip 22. Thus, since the rise in the junction temperature of the LED chip 22 can be suppressed, the light conversion efficiency in the LED chip 22 is increased, and as a result, the lighting device can realize low power consumption of the entire device.

  Further, in the illumination device 1e, the lens optical device 14 is arranged on the substrate surface 6b of the circuit substrate 6, in other words, on the substrate surface of the circuit substrate 6 that does not have the wiring pattern 7, so that the lens optical element As a lens 14, it is possible to use a lens optical element made of a resin having a low heat-resistant temperature. Thereby, cost reduction is realizable in manufacturing the illuminating device 1e.

  In the present embodiment, the circuit board 6 is described as a single-sided board having the wiring pattern 7 only on the board surface 6a. However, the wiring pattern 7 may be partially arranged on the board surface 6b. For example, even if the wiring pattern 7 on the substrate surface 6a side and the wiring pattern 7 on the substrate surface 6b side are not thermally coupled or thermally coupled, the lens optical element 14 is thermally Needless to say, in the case where the wiring pattern 7 is provided on the substrate surface 6b within the range where the influence is not exerted, the same effect as the lighting device 1e is obtained.

[Embodiment 6]
Embodiment 6 of the present invention will be described below with reference to FIG. FIG. 8 is a cross-sectional view showing a heat dissipation structure of the lighting device 1f according to the present embodiment. In addition, the illuminating device 1f shown in Embodiment 6 is a modification of the illuminating device 1e shown in Embodiment 5, and in the following Embodiment 6, a different part from said Embodiment 6 is demonstrated, and the same function is demonstrated. The members having the same function are designated by the same reference numerals and the description thereof is omitted.

  First, the illumination device 1f shown in the present embodiment is different from the illumination device 1e in the fifth embodiment in that spacers 15 and 16 for forming a gap between the lens optical element 14 and the circuit board 6 are provided. That is.

  As shown in FIG. 8, the pin 14 a is inserted into the circuit board 6, and the lens optical element 14 is fixed to the circuit board 6. Here, in the lighting device 1f, spacers 15 and 16 are arranged for the two pins 14a so as to surround the periphery of the pin 14a. Thus, the lens optical element 14 is fixed to the circuit board 6 in a state where a gap is generated between the circuit board 6 and the lens optical element 14 by the height of the spacers 15 and 16.

  Thus, by providing a gap between the circuit board 6 and the lens optical element 14, the air inside the lens optical element 14 can easily circulate with the air outside the lens optical element 14 through this gap. Therefore, the illuminating device 1 f provided with the spacers 15 and 16 can suppress an increase in the temperature of the air inside the lens optical element 14, and as a result, has an effect of suppressing an increase in the junction temperature of the LED chip 22. The effect of suppressing the increase in the junction temperature of the LED chip 22 is as described above.

  In the present embodiment, the spacers 15 and 16 are configured as members different from the lens optical element 14, but the lens optical element 14 may be integrated with the spacers 15 and 16. Also in this case, the same effects as the case where the spacers 15 and 16 are configured as members different from the lens optical element 14 are obtained.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  In addition, you may comprise the illuminating device of this invention as follows.

(First configuration)
A package having a light emitting element inside and having a lead terminal to which an electrode of the light emitting element is electrically connected, a through hole for inserting and disposing the package, and a lead terminal of the package are connected An illuminating device comprising: a circuit board having a wiring pattern; and a heat radiating member provided via an insulating material on a main surface side of the circuit board where the lead terminal and the connection part of the wiring pattern are provided .

(Second configuration)
The lighting device according to the first configuration, wherein the light emitting element is a light emitting diode.

(Third configuration)
The circuit board has no wiring pattern installed on the surface opposite to the main surface, or the area of the wiring pattern installed on the main surface is installed on the surface opposite to the main surface. The illumination device according to the first configuration or the second configuration, wherein the illumination device is larger than an area of the wiring pattern.

(Fourth configuration)
The heat dissipating member is a housing made of metal, and the housing, the circuit board, and the insulating material are fixed via screws. The illuminating device as described in any one structure from a 3rd structure to 3rd structure.

(Fifth configuration)
The lighting device according to any one of the first to fourth configurations, wherein the housing has a recess in a portion where the light emitting diode is installed.

(Sixth configuration)
A package having a light emitting element inside and having a lead terminal to which an electrode of the light emitting element is electrically connected, a through hole for inserting and disposing the package, and a lead terminal of the package are connected A circuit board having a wiring pattern; a heat dissipating member provided via an insulating material on the main surface side of the circuit board where the lead terminal and the connection part of the wiring pattern are provided; and a distribution of emitted light from the light emitting element. An illuminating device comprising: an optical element that is positioned above the light emitting element and attached to the circuit board for the purpose of changing light characteristics.

(Seventh configuration)
The illumination device according to the sixth configuration, wherein the optical element is made of resin, and diffuses or collects light by transmitting or reflecting light emitted from the light emitting element.

(Eighth configuration)
The optical element is provided with a positioning pin for positioning on the circuit board, and the circuit board is provided with a through hole for inserting the pin of the optical element. The illumination device according to the sixth configuration or the seventh configuration.

  The present invention provides an illumination device that can efficiently dissipate heat generated by a light-emitting element, and can be used particularly in illumination applications as an alternative to light bulbs and fluorescent lamps and in pack lights of liquid crystal displays. .

It is sectional drawing which shows the thermal radiation structure of the illuminating device based on the 1st Embodiment of this invention. It is sectional drawing which shows the thermal radiation structure of the illuminating device which the chassis has a hollow and a convex part based on the 2nd Embodiment of this invention. It is sectional drawing which shows the thermal radiation structure of the illuminating device with which the circuit board and the chassis were fixed with the screw based on the 3rd Embodiment of this invention. It is sectional drawing which shows the thermal radiation structure of the illuminating device which attached the heat sink to the chassis based on the 4th Embodiment of this invention. It is the schematic diagram which looked at the illuminating device based on the 5th Embodiment of this invention from the emission direction of light. It is sectional drawing which shows the thermal radiation structure of the illuminating device provided with the optical element based on the 5th Embodiment of this invention. It is a schematic diagram which shows the structure of the circuit board with which the illuminating device which concerns on the 5th Embodiment of this invention is provided. It is sectional drawing which shows the thermal radiation structure of the illuminating device provided with the spacer between the circuit board and optical element based on the 6th Embodiment of this invention. It is sectional drawing which shows the thermal radiation structure of the illuminating device in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Illuminating device 1b Illuminating device 1c Illuminating device 1d Illuminating device 1e Illuminating device 1f Illuminating device 6 Circuit board 7 Wiring pattern 10a Heat radiation sheet (insulating material)
10b Heat dissipation sheet (insulating material)
10c Heat dissipation sheet (insulating material)
11a Chassis (heat dissipation member)
11b Chassis (heat dissipation member)
11c Chassis (heat dissipation member)
12 screw 14 lens optical element (optical element)
14a pin (protrusion)
20 LED package (light emitting unit)
22 LED chip (light emitting device)
24 electrode 25 electrode 72 wiring pattern 73 electrode pattern (connection part)
74 Wiring pattern 75 Electrode pattern (connection part)
76 Fixing hole (insertion hole)
77 Fixing hole (insertion hole)
78 Screw hole 79 Screw hole

Claims (10)

A light emitting unit having a light emitting element and an electrode electrically connected to the light emitting element;
A circuit board having a connection portion connected to the electrode and a wiring pattern connected to the connection portion on the same surface;
A heat dissipating member having an insulating material on the surface,
The luminous body unit is disposed on the heat dissipation member via the insulating material,
The surface of the circuit board on which the connecting portion is disposed and the surface of the heat dissipation member on which the light emitting unit is disposed are opposed to each other.
At least one part of the said wiring pattern is in contact with the said insulating material on the said heat radiating member, The illuminating device characterized by the above-mentioned.   The lighting device according to claim 1, wherein the light emitting element is a light emitting diode.   The lighting device according to claim 1, wherein the wiring pattern is disposed only on a surface of the circuit board having the connection portion. The wiring pattern is disposed on both sides of the circuit board,
In the circuit board, the area of the wiring pattern disposed on the surface having the connection portion is larger than the area of the wiring pattern disposed on the surface opposite to the surface having the connection portion. The lighting device according to claim 1 or 2. Both the heat dissipation member and the circuit board have screw holes for inserting screws,
5. The lighting device according to claim 1, wherein the circuit board is fixed to the heat dissipation member with the screws. 6.   6. The lighting device according to claim 1, wherein a region in which the light emitting unit is disposed is recessed in the heat radiating member.   7. The heat dissipation member according to claim 1, wherein the heat dissipating member has at least one convex portion on a surface opposite to a surface on which the light emitting unit is disposed. The lighting device described in 1. An optical element that changes the light distribution characteristics of the light emitted from the light emitting element,
The illumination device according to any one of claims 1 to 7, wherein the optical element is disposed so as to cover a light emitting element disposed on the heat dissipation member.   The illumination device according to claim 8, wherein the optical element diffuses or collects the emitted light by transmitting or reflecting the emitted light from the light emitting element. The optical element includes a protrusion at a contact portion with the circuit board,
The lighting device according to claim 8 or 9, wherein the circuit board includes an insertion hole for inserting the protrusion.

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