JP2012038894A - Substrate module for mounting heat generator, and illumination device - Google Patents

Abstract

A substrate module for mounting a heat source that can improve heat dissipation characteristics with a simple configuration, and that exhibits narrow heat dissipation characteristics even when used in a lighting device such as a fluorescent tube type, which is narrow and narrow. An object of the present invention is to provide a lighting device including the substrate module for mounting the heat source.
A heat source mounting board module (1) in which a flexible printed wiring board (20) for mounting a heat source (30) is attached to a metal plate (10), wherein the flexible printed wiring board (20) is connected to the metal plate (10). The surface of the metal plate 10 having a larger area than that of the dimension and having a conductive layer 22 is bent from one side of the metal plate 10 to the other side, and is in contact with the one side and the other side. It is the board module for mounting a heat source characterized by being attached to.
[Selection] Figure 2

Description

  The present invention relates to a heat source mounting substrate module and a lighting device including the heat source mounting substrate module.

A semiconductor element that generates heat during operation (hereinafter referred to as a heat generation source) generates heat when driven. The heat varies depending on the type of heat source, but the performance of the heat source tends to decrease with increasing temperature.
In recent years, methods for reducing the amount of heat generation by improving the performance of the heat source itself have been developed, but many methods for heat dissipation have been developed as to how to remove heat in parallel.
As such a heat source, there is a light emitting diode (hereinafter referred to as an LED), which is being used for lighting as a light-emitting element that can save energy and improve the power-light conversion efficiency. .
However, even though the efficiency has improved, it is true that more than half of the input power is consumed as heat, and the life of the LED is reduced by that heat, so how can heat be released? It has become a challenge.
The LED has an element itself of about 0.3 to 1 mm, and may be mounted on a circuit board after being mounted on a ceramic substrate or a lead frame, or may be directly mounted on a circuit board. Some circuit boards use flexible printed wiring boards, and some of them are put into practical use.
As an example of a flexible printed wiring board on which such an LED is mounted, there is, for example, Patent Document 1 below.

JP 2002-184209 A

The above-mentioned Patent Document 1 is an invention related to a lighting device. In the manufacturing process, the three-dimensional arrangement work of light emitting diodes is automated to improve production efficiency, and the light emitting efficiency decreases as the temperature of the light emitting diode rises. There is an advantage that higher light output can be obtained.
However, the above Patent Document 1 is an invention related to a cylindrical lighting device, and is not intended to be a narrow and elongated lighting device such as a fluorescent tube type, nor is there such description or suggestion. However, in a lighting device such as a fluorescent tube type in which the degree of design freedom for heat radiation does not work, the width is narrow and long, there is a problem that sufficient heat radiation characteristics may not be obtained.

  Therefore, the present invention solves the above-mentioned problems in the prior art, can improve heat dissipation characteristics with a simple configuration, and has excellent heat dissipation characteristics even when used in a lighting apparatus such as a fluorescent tube type having a narrow and narrow width. It is an object of the present invention to provide a heat source mounting board module that can be exhibited and a lighting device including the heat source mounting board module.

  The heat source mounting board module of the present invention is a heat source mounting board module in which a flexible printed wiring board for mounting a heat source is attached to a metal plate, wherein the flexible printed wiring board is the metal plate. And having a conductive layer on the surface, bend from one side of the metal plate to the other side, and be in contact with the one side and the other side. The first feature is that it is attached.

According to the first feature of the present invention, the heat source mounting board module is a heat source mounting board module in which a flexible printed wiring board for mounting the heat source is attached to a metal plate, The flexible printed wiring board has a larger area than the dimension of the metal plate, and has a surface provided with a conductive layer, bends from one side of the metal plate to the other side, Since it is attached in contact with the other side, the conductive layer of the flexible printed wiring board is used to dissipate the heat generated by the heat source and the heat generated from the heat source to the metal plate. It can be used as a heat dissipation path for heat dissipation to dissipate heat, and the surface area of the heat dissipation layer, the number of heat dissipation paths, and the area can be increased with a simple configuration.
Therefore, the heat dissipation characteristics can be improved with a simple configuration.
In addition, by bending the flexible printed wiring board from one side of the metal plate to the other side and attaching it to the one surface side and the other surface side, even when the width of the metal plate is narrow, It is possible to increase the surface area of the heat dissipation layer, the number of heat dissipation paths, and the area for radiating the heat generated by the heat generation source with a simple configuration. Therefore, a heat source mounting board module having a narrow width and excellent heat dissipation characteristics can be formed with a simple configuration.

  In addition to the first feature of the present invention, the heat source mounting substrate module of the present invention has a second feature that the metal plate is an aluminum plate.

  According to the second feature of the present invention, in addition to the function and effect of the first feature of the present invention, since the metal plate is an aluminum plate, an aluminum plate with good thermal conductivity is used. Thus, the heat generated by the heat source that is transferred through the flexible printed wiring board can be efficiently radiated. Therefore, it is possible to obtain a substrate module for mounting a heat source that is further excellent in heat dissipation characteristics.

  In addition to the first or second feature of the present invention, the substrate module for mounting a heat source according to the present invention has a third feature that the conductive layer is provided on both surfaces of the flexible printed wiring board. It is said.

  According to the third feature of the present invention, in addition to the operational effects of the first or second feature of the present invention, the conductive layer is provided on both surfaces of the flexible printed wiring board. The heat dissipation characteristics can be further improved with a simple configuration.

  In addition to the any one of the first to third features of the present invention, the substrate module for mounting the heat source of the present invention has a fourth feature that the heat source is a light emitting element.

  According to the fourth aspect of the present invention, in addition to the function and effect of any one of the first to third aspects of the present invention, the heat source is a light emitting element, and thus has a simple configuration. A substrate module for mounting a heat source for a lighting device having excellent heat dissipation characteristics can be obtained. In particular, a substrate module for mounting a heat source that can exhibit excellent heat dissipation characteristics even when used in a lighting apparatus such as a fluorescent tube type that is narrow and narrow can be obtained.

  Moreover, the illuminating device of this invention has the board | substrate module for heat source mounting of Claim 4 as a 5th characteristic.

  According to the fifth aspect of the present invention, since the lighting device includes the substrate module for mounting a heat source according to claim 4, the lighting device can have a simple structure and excellent heat dissipation characteristics. In particular, in a lighting device such as a fluorescent tube type having a narrow and narrow width, a lighting device having a simple structure and excellent heat dissipation characteristics can be obtained.

  According to the substrate module for mounting the heat source of the present invention and the lighting device including the substrate module for mounting the heat source, the heat dissipation characteristics can be improved with a simple configuration, and the width is narrow and long, like a fluorescent tube type. Even when used in a lighting device, a substrate module for mounting a heat source that can exhibit excellent heat dissipation characteristics can be obtained. Moreover, it can be set as the illuminating device excellent in the thermal radiation characteristic by simple structure. In particular, in a lighting device such as a fluorescent tube type having a narrow and narrow width, a lighting device having a simple structure and excellent heat dissipation characteristics can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which simplifies and shows the board | substrate module for heat source mounting concerning embodiment of this invention, (a) is a whole perspective view, (b) is a top view of (a). It is sectional drawing in the aa line direction of FIG.1 (b). FIG. 3 is a diagram showing a simplified movement of heat generated by a heat source in a heat source mounting substrate module, where (a) is a diagram showing a heat source mounting substrate module according to an embodiment of the present invention, and (b) is a diagram showing It is a figure which shows the conventional substrate module for heat source mounting. BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows simply the formation method of the illuminating device which comprises the substrate module for heat-source mounting concerning embodiment of this invention, and the substrate module for heat-source mounting, (a) And (b) is flexible printed wiring The figure which shows a board attachment process, (c) is a figure which shows a heat-source mounting process.

  Embodiments of a heat source mounting board module and a lighting device including the heat source mounting board module according to the present invention will be described with reference to the following drawings to provide an understanding of the present invention. However, the following description is an embodiment of the present invention, and does not limit the contents described in the claims.

A substrate module 1 for mounting a heat source according to an embodiment of the present invention is an illumination module disposed inside a fluorescent tube type illumination device having a narrow and narrow width (not shown).
As shown in FIG. 1, the heat generating source mounting board module 1 includes a metal plate 10 and a flexible printed wiring board 20, and a plurality of heat generating sources 30 are arranged in parallel on the upper surface of the flexible printed wiring board 20. And mounted inside a fluorescent tube type lighting device (not shown).

As shown in FIG. 1, the metal plate 10 is an elongated plate-like body, serves as a base of the heat source mounting substrate module 1, and generates heat generated when the heat source 30 is driven to generate a flexible printed wiring board 20. It is for transferring heat through and dissipating heat.
In the present embodiment, the metal plate 10 is formed of an aluminum plate. Thus, by using the structure using an aluminum plate with good thermal conductivity, the substrate module 1 for mounting a heat source that has excellent heat radiation characteristics and can be reduced in weight can be obtained.
In addition, as for the width A of the metal plate 10 shown in FIG.1 (b), it is desirable to set it as 15 mm or less. By setting it as such a structure, it can be set as the substrate module 1 for heat source mounting with a narrow width | variety suitable for a fluorescent tube type illuminating device.
The length and thickness of the metal plate 10 can be changed as appropriate.

The flexible printed wiring board 20 is a so-called single-sided flexible printed wiring board provided with a conductive layer only on one side, and is attached to the metal plate 10 with an adhesive S as shown in FIG. The heat source 30 to be mounted is electrically connected to an external wiring (not shown), and heat generated when the heat source 30 is driven is radiated.
As shown in FIG. 2, the flexible printed wiring board 20 includes a base material layer 21, a conductive layer 22, and a coverlay layer 23.

The said base material layer 21 is a layer used as the base of the flexible printed wiring board 20, and is formed with the insulating resin film.
As a resin film, what consists of a resin material excellent in the softness | flexibility is used. For example, any resin film may be used as long as it is normally used as a resin film for forming a flexible printed wiring board such as a polyimide film or a polyester film.
In particular, those having high heat resistance in addition to flexibility are desirable. For example, polyamide resin films, polyimide resin films such as polyimide and polyamideimide, and polyethylene naphthalate can be preferably used.
The heat-resistant resin may be any resin as long as it is normally used as a heat-resistant resin for forming a flexible printed wiring board, such as a polyimide resin or an epoxy resin.
The base material layer 21 preferably has a thickness of about 13 to 50 μm.

The conductive layer 22 mainly includes a circuit region for forming an electric circuit for electrical connection between the heat source 30 and an external wiring (not shown), and a heat dissipation region for dissipating heat generated by the heat source 30. It is.
As shown in FIG. 2, the conductive layer 22 is a layer made of a conductive metal foil that is laminated on the upper surface of the base material layer 21.
In the present embodiment, as shown in FIG. 2, in the conductive layer 22, a region where an electric circuit is formed is a circuit region 22 a, and a region for radiating heat generated by the heat generation source 30 is a heat dissipation region 22 b. It is as.
As shown in FIG. 2, the circuit region 22a and the heat dissipation region 22b are formed by using a known forming method such as etching the same conductive layer 22. With such a configuration, the circuit region 22a and the heat dissipation region 22b can be easily formed.
As the conductive metal foil, for example, copper can be used. Of course, it is not limited to copper, and any material may be used as long as it is normally used as a conductive metal foil for forming the conductive layer of the flexible printed wiring board 20.
The thickness of the conductive layer 22 is preferably about 18 to 105 μm.
Note that an electric circuit (not shown) formed in the circuit region 22 a is electrically connected to an electrode (not shown) formed on the heat source 30 via solder H.

The coverlay layer 23 is a layer that forms an insulating layer of the flexible printed wiring board 20. As shown in FIG. 2, the cover lay layer 23 is formed by attaching the cover lay 23b to the base material layer 21 and the conductive layer 22 through a cover lay adhesive 23a made of a thermosetting adhesive or the like. ing. Further, a through hole 23 c for filling the solder H is formed at a position corresponding to the heat source 30.
As the coverlay 23b, a polyimide film, a photosensitive resist, a liquid resist, or the like can be used.
The coverlay layer 23 preferably has a thickness of about 13 to 50 μm.

In this embodiment, as shown in FIGS. 1, 2, and 4, the dimensions of the flexible printed wiring board 20 including the base material layer 21, the conductive layer 22, and the coverlay layer 23 are the same as those of the metal plate 10. The flexible printed wiring board 20 is bent from the upper surface side which is one surface side of the metal plate 10 to the lower surface side which is the other surface side, and the metal plate is interposed via the adhesive S. 10 are attached to the entire surface of the upper surface side and the lower surface side in a contact state.
With such a configuration, the conductive layer 22 of the flexible printed wiring board 20 causes the heat generated in the heat source 30 to dissipate the heat generated in the heat source 30 and the heat generated in the heat source 30 to the metal plate 10. It can be used as a heat dissipation path for dissipating heat, and the surface area of the heat dissipation layer, the number of heat dissipation paths, and the area can be increased with a simple configuration. Therefore, the heat dissipation characteristics can be improved with a simple configuration.

More specifically, as shown in FIG. 2, the heat generated in the heat source 30 is transferred to the conductive layer 22 constituting the circuit region 22a and transferred to the entire conductive layer 22 constituting the heat dissipation region 22b. Can be heated. Therefore, the entire region of the conductive layer 22 can be used as a heat dissipation layer for dissipating heat generated by the heat source 30 by heat exchange (convection / radiation) with air.
Further, as shown in FIG. 2, the flexible printed wiring board 20 is bent from the upper surface side to the lower surface side of the metal plate 10 and attached to the entire surface of the upper surface side and the lower surface side so that the heat radiation layer is formed. The surface area can be increased with a simple configuration, and heat dissipation by heat exchange with air can be promoted. Accordingly, the substrate module 1 for mounting a heat source having a simple configuration and excellent heat dissipation characteristics can be obtained.
Further, as shown in FIG. 2, the flexible printed wiring board 20 is bent from the upper surface side to the lower surface side of the metal plate 10 and attached to the entire surface of the upper surface side and the lower surface side of the metal plate 10 to generate heat. The heat generated by the source 30 can be transferred from the conductive layer 22 constituting the circuit region 22 a contacting the upper surface side of the metal plate 10 to the upper surface side of the metal plate 10 and can be radiated from the metal plate 10. Further, as shown in FIG. 2, the heat generated by the heat source 30 is also transferred from the conductive layer 22 constituting the heat radiation area 22b in contact with the lower surface side of the metal plate 10 to the lower surface side of the metal plate 10, so that the metal Heat can be dissipated from the plate 10. Therefore, the conductive layer 22 can be used as a heat dissipation path for transferring the heat generated by the heat source 30 to the metal plate 10 and dissipating it, and the heat dissipation paths are provided on the upper surface side and the lower surface side of the metal plate 10. be able to. Therefore, the number and area of heat radiation paths can be increased with a simple configuration, and the thermal resistance can be lowered. Therefore, the heat source mounting substrate module 1 having a simple configuration and excellent heat dissipation characteristics can be obtained.

That is, in the conventional heat source mounting substrate module 2 in which the flexible printed wiring board 50 is attached only to the upper surface side of the metal plate 40 via the adhesive S and the heat source 60 is mounted as shown in FIG. The flexible printed wiring board 50 that can be used as a heat dissipation layer and a heat dissipation path is configured to be provided only on the upper surface side of the metal plate 40.
Therefore, there has been a problem that the surface area of the heat dissipation layer, the number and area of the heat dissipation paths are limited, and the heat dissipation characteristics are poor. This is more remarkable when the heat source mounting substrate module 2 is used in a fluorescent tube type lighting device in which the metal plate 40 has a narrow width.
In this case, the surface area of the heat radiation layer can be increased by extending the dimensions of the flexible printed wiring board 50 in the horizontal direction with respect to the upper surface of the metal plate 40. Is used in a fluorescent tube type lighting device having a narrow and narrow width, there is a problem that it is impossible to adopt such a configuration.

On the other hand, by setting it as the structure of this embodiment, as shown to Fig.3 (a), the surface area of a thermal radiation layer, the number of thermal radiation paths, and an area can be increased with a simple structure. Accordingly, the substrate module 1 for mounting a heat source having a simple configuration and excellent heat dissipation characteristics can be obtained.
Further, as shown in FIG. 3A, the surface area of the heat radiation layer, the number of heat radiation paths, and the area can be increased while the width B of the heat source mounting substrate module 1 is kept close to the width A of the metal plate 10. it can. Therefore, even when the metal plate 10 is a narrow and narrow metal plate, the heat source mounting substrate module 1 can be a heat source mounting substrate module that has excellent heat dissipation characteristics and is suitable for a fluorescent tube type lighting device. .
In FIG. 3, the movement of heat generated by the heat source in the heat source mounting substrate module is indicated by a white arrow, and the configuration of the flexible printed wiring board 20 is illustrated in order to effectively explain the heat movement. It shall be shown in a simplified manner.
As the adhesive S, a thermosetting adhesive or the like can be used.

The heat source 30 is a semiconductor element that generates heat during operation.
As shown in FIG. 1, a plurality of the heat sources 30 are mounted in parallel on the upper surface of the flexible printed wiring board 20. More specifically, as shown in FIG. 2, an electrode (not shown) of the heat source 30 and an electric circuit (not shown) formed in the circuit region 22 a of the flexible printed wiring board 20 are electrically connected via solder H. The
In the present embodiment, a light emitting diode (LED) made of gallium nitride as a light emitting element is used as the heat source 30.
Of course, the material for forming the light emitting diode (LED) is not limited to gallium nitride, and can be appropriately changed depending on the color to be developed.
Further, the heat source 30 is not limited to the light emitting element, and can be appropriately changed depending on the use of the heat source mounting board module, and the size, the number mounted on the flexible printed wiring board 20, the mounting position, etc. The present invention is not limited to the embodiment, and can be changed as appropriate.

Next, with reference to FIG. 4, the formation method of the illuminating device provided with the substrate module 1 for heat source mounting and the substrate module 1 for heat source mounting which concerns on this embodiment is demonstrated.
First, referring to FIG. 4A, a flexible printed wiring board 20 formed in an area larger than the dimension of the metal plate 10 by the flexible printed wiring board mounting step P is attached to the metal plate via the adhesive S. 10 is attached to the entire surface on the upper surface side.
4B, the flexible printed wiring board 20 is bent from the upper surface side to the back surface side of the metal plate 10 through the flexible printed wiring board mounting step P, and the metal plate 10 is interposed via the adhesive S. Attach to the entire surface on the lower surface side of the.
Through the above steps, the heat source mounting substrate module 1 is formed.
Then, referring to FIG. 4C, after the heat source 30 is mounted at a predetermined position of the flexible printed wiring board 20 through the solder H (see FIG. 2) in the heat source mounting step Q, a fluorescent tube (not shown) is shown. A substrate module 1 for mounting a heat source is disposed in a type of lighting device.
An illuminating device provided with the heat source mounting substrate module 1 is formed through the above steps.
In addition, the formation method of the illuminating device provided with the substrate module 1 for mounting the heat source and the substrate module 1 for mounting the heat source is not limited to the one in the present embodiment, and can be changed as appropriate.

In the present embodiment, the flexible printed wiring board 20 is configured as a so-called single-sided flexible printed wiring board in which a conductive layer is provided only on the surface on one side. However, the configuration is not necessarily limited to such a configuration. A so-called double-sided flexible printed wiring board in which conductive layers are provided on both surfaces of the one side and the other side of the flexible printed wiring board 20 may be employed. By setting it as such a structure, the surface area and cross-sectional area of the conductive layer used as a heat radiating layer can be increased further. Therefore, the heat dissipation characteristics can be further improved with a simple configuration.
Further, the area of the conductive layer 22, the positions and areas of the circuit region 22a and the heat radiation region 22c are not limited to those of the present embodiment, and can be changed as appropriate. However, the area of the conductive layer 22 is preferably as large as possible in consideration of heat dissipation.

(Example)
A heat source mounting board module 1 according to an embodiment of the present invention shown in FIG. 3 and a conventional heat source mounting board module 2 as a comparative example are formed under the same conditions as shown below, and the number of LEDs mounted is 5 The LED junction temperature (the temperature of the pn junction) was compared between the calculated value and the actually measured value, assuming that the interval between the adjacent LEDs was 25 mm and the input power to each LED was 1 W.
As shown in FIG. 3, the width (length in the short direction) B of the heat source mounting substrate module 1 according to the present embodiment is 16.5 mm.
-Metal plate Material: Aluminum substrate Width (length in the short direction): 15 mm, thickness: 1.5 mm
・ Flexible printed wiring board (base material layer)
Material: Polyimide Thickness: 25μm
(Conductive layer)
Material: Copper foil Thickness: 35μm
(Coverlay layer)
Material: Polyimide Thickness: 13μm
・ Adhesive Material: Thermosetting adhesive Thickness: 25μm

  In the substrate module 1 for mounting a heat source according to the embodiment of the present invention, the calculated value was 49 ° C. and the measured value was 53 ° C., whereas in the conventional substrate module 2 for mounting a heat source, the calculated value was 63 ° C. The measured value was 61 ° C. From this result, it can be seen that the heat generating source mounting substrate module 1 according to the embodiment of the present invention can improve the heat dissipation effect by about 20% compared to the conventional heat generating source mounting substrate module 2.

  According to the present invention, in the heat source mounting board module in which the flexible printed wiring board for mounting the heat source is attached to the metal plate, the heat dissipation characteristics can be improved with a simple configuration. Industrial applicability is high in the field of lighting devices including a heat source mounting board module in which a flexible printed wiring board for mounting is mounted on a metal plate.

DESCRIPTION OF SYMBOLS 1 Substrate module for heat source mounting 2 Substrate module for heat source mounting 10 Metal plate 20 Flexible printed wiring board 21 Base material layer 22 Conductive layer 22a Circuit area 22b Heat radiation area 23 Coverlay layer 23a Coverlay adhesive 23b Coverlay 23c Through hole 30 Heat source 40 Metal plate 50 Flexible printed circuit board 60 Heat source A Width B Width H Solder P Flexible printed circuit board mounting process Q Heat source mounting process S Adhesive

Claims (5)

  A heat source mounting board module in which a flexible printed wiring board for mounting a heat source is attached to a metal plate, the flexible printed wiring board having a larger area than the size of the metal plate A heat source mounting characterized in that a conductive layer is provided on the surface, bent from one side of the metal plate to the other side, and attached to the one side and the other side in a contact state. Board module.   The heat source mounting substrate module according to claim 1, wherein the metal plate is an aluminum plate.   The heat generating source mounting board module according to claim 1, wherein the conductive layer is provided on both surfaces of the flexible printed wiring board.   The heat generating source mounting substrate module according to claim 1, wherein the heat generating source is a light emitting element.   An illuminating device comprising the substrate module for mounting a heat source according to claim 4.

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