JP2007180163A - Light emitting device module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce mutual thermal influences even if a plurality of light emitting devices are disposed closely in a light emitting device module. <P>SOLUTION: The light emitting device module comprises light emitting devices 4A, 4B, 4C, and 4D disposed adjacently at closer positions as compared with the size of a light emission surface, protrusions 2A, 2A divided into a plurality of parts for supporting the light emitting devices, telescopic modules 3, a heat insulating member 5 for regulating heat transfer between these protrusions 2A and the telescopic modules 3, and a circumference atmosphere layer 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting device module including a plurality of light emitting devices. For example, the present invention relates to a light emitting device module that can be suitably used for projectors, displays, indicators, traffic signs, lighting, and the like.

Conventionally, for example, by providing a plurality of solid light emitting elements such as light emitting diodes (hereinafter referred to as LEDs), a light emitting device that improves light emission luminance or emits white light or color light by combining solid light emitting elements having different wavelengths. Module is known.
In these light emitting device modules, in order to avoid the influence of self-heating at the time of light emission, each light emitting device is disposed on the electrode and the substrate sufficiently apart.
As an example of such a light emitting device module, Patent Document 1 describes a chip type LED in which LED chips capable of emitting green, red, and blue light are arranged on a common electrode. The common electrode is desirably made as large as possible in consideration of the heat dissipation and reflectivity of the LED. The drawing shows that the distance between adjacent LED chips of a substantially square shape is clearly larger than the dimension of one side.
Further, in Patent Document 2, substantially square light-emitting elements made of at least three or more LEDs are arranged at equal intervals on one base made of a resin such as ceramics or epoxy resin, and the upper part is transparent. A light-emitting device that is covered with a light-sensitive member is described. An example is described in which the intervals between the light emitting elements are equal to or wider than one side of a substantially square.
Japanese Patent No. 3329716 (FIG. 1) Japanese Patent Laying-Open No. 2005-159262 (FIG. 1-9)

The conventional light emitting device module as described above has the following problems.
In the techniques of Patent Documents 1 and 2, a plurality of light emitting devices are arranged on the same electrode, substrate, base, and other heat dissipating members at an adjacent distance equal to or greater than the size of the light emitting surface. Although the light-emitting device is cooled by heat dissipation, the amount of heat generation increases and it becomes susceptible to mutual thermal effects. For example, the luminous efficiency deteriorates and the luminance decreases, and the life span is shortened. There is.
In order to remove such a thermal influence, it is necessary to increase the size of the heat dissipating member or increase the arrangement interval, so that it is difficult to arrange the light emitting devices close to each other.
In a light-emitting device module composed of a plurality of light-emitting devices having such a separation distance, when the light emitted from each of the light-emitting device modules is collected by a common optical system, the light-emitting device modules arranged so as to be shifted from the optical axis of the optical system are used. There is a problem that the light utilization efficiency is lowered and the aberration is deteriorated. For example, when a plurality of light emitting devices are provided in order to increase luminance, the light use efficiency may deteriorate. In addition, when color display is performed using a plurality of light beams, there is a problem that color unevenness is likely to occur.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a light emitting device module that can reduce the mutual thermal influence even when a plurality of light emitting devices are arranged close to each other. And

In order to solve the above problems, a light emitting device module of the present invention includes a plurality of light emitting devices arranged adjacent to a position close to the size of the light emitting surface, and at least one of the plurality of light emitting devices. A heat dissipation base portion divided into a plurality of parts that support the heat sink and a heat transfer restriction portion that restricts heat transfer between the plurality of heat dissipation base portions.
According to the present invention, at least one of the plurality of light emitting devices arranged adjacent to the proximity position is supported by the divided heat dissipation base portion, and heat transfer between the heat dissipation base portions is performed by the heat transfer restriction portion. Since it regulates, the thermal influence between the light emitting devices arrange | positioned on a different thermal radiation base part can be reduced.
Here, the “position close to the size of the light emitting surface” means that the distance between the two adjacent light emitting devices in the adjacent direction is shorter than the average value of the width dimensions of the light emitting devices in the adjacent direction. It shall mean the position.

  According to the light emitting device module of the present invention, by providing a heat transfer restricting portion to restrict heat transfer between the heat dissipating base portions, it is possible to reduce the thermal influence between the light emitting devices arranged on different heat dissipating base portions. Therefore, even if a plurality of light emitting devices are arranged close to each other, the lifetime of the light emitting device can be improved, and the luminance can be reduced due to thermal influence.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common description is omitted.

[First Embodiment]
A light emitting device module according to a first embodiment of the present invention will be described.
FIG. 1A is a plan view showing a schematic configuration of the light emitting device module according to the first embodiment of the present invention. FIG.1 (b) is AA sectional drawing of Fig.1 (a). FIG. 2 is an exploded perspective view of the light emitting device module according to the first embodiment of the present invention. FIGS. 3A, 3B, and 3C are plan views showing examples of arrangement of light emitting devices in the first embodiment of the present invention.

The light-emitting device module 1 of the present embodiment includes a plurality of light-emitting devices, and can be suitably used as a light source for, for example, a projector, a display, an indicator, a traffic sign, and lighting by emitting them.
As shown in FIGS. 1 and 2, the schematic configuration of the light emitting device module 1 includes light emitting devices 4A, 4B, 4C, and 4D, a module base 2, a heat insulating member 5, and a nested module 3.

The light-emitting devices 4A, 4B, 4C, and 4D are solid-state light-emitting elements having a light-emitting surface that is rectangular in a plan view and has a dimension H in the vertical direction and a dimension W in the horizontal direction in FIG. As the solid-state light emitting element, an appropriate one can be adopted, but in this embodiment, an LED is adopted. Since a known appropriate structure can be adopted for the LED chip structure, the entire chip is schematically represented by a flat plate in the drawing. Although not particularly shown, it goes without saying that electrodes, wire electric wires, and the like are provided according to the respective structures.
As the wavelengths and rated outputs of the light emitting devices 4A, 4B, 4C, and 4D, appropriate ones can be adopted, and the size of the light emitting surface may be changed accordingly. The description will be made assuming that the size is × W.

The module base 2 supports the light emitting devices 4A and 4C in a positional relationship in which the light emitting devices 4A and 4C are aligned in the respective diagonal directions, and projects light emitted from the light emitting devices 4A and 4C toward the front side of the sheet of FIG. The heat from 4C is conducted to dissipate heat.
In the present embodiment, through-hole portions 2B and 2B are provided in the diagonal direction of the block member having a substantially rectangular shape D in plan view, and are formed in a substantially rectangular parallelepiped shape slightly spaced diagonally in the other diagonal direction. Convex portions 2A and 2A are formed. That is, each through-hole portion 2B is surrounded by an L-shaped side wall 2d in plan view that connects each convex portion 2A and the convex side surfaces 2b, 2b of the convex portion 2A.
Then, the shape of the module base 2 in plan view is substantially divided into four rectangular regions by the convex portions 2A and 2A and the through-hole portions 2B and 2B.
The material of the module base 2 may be any material as long as it has good thermal conductivity and excellent heat dissipation. For example, a material such as metal, semiconductor, ceramics, and synthetic resin may be employed. it can.

A light emitting device arrangement surface 2a on which the light emitting device 4A (4C) is arranged is formed on the upper surface of the convex portion 2A. In the present embodiment, the areas of the light emitting device arrangement surfaces 2a and 2a are larger than the areas of the light emitting surfaces of the light emitting devices 4A and 4C, respectively, and the light emitting devices 4A and 4C emit light at the corners on the center side of the module base 2. It arrange | positions so that each edge | side of a surface may substantially align with the outer peripheral part of 2 A of convex parts.
The light emitting device arrangement surface 2a is a plane connected to the light emitting device 4A (4C) in an electrically insulating state or a conductive state as necessary. In order to efficiently emit light from the light emitting device 4A (4C) in the protruding direction of the convex portion 2A, it is preferable that a reflective surface is formed at least in the arrangement region of the light emitting device 4A (4C).

The thermal insulation member 5 regulates heat conduction between the module base 2 and the nested module 3 described later, thereby reducing heat transfer and thermally insulating the heat insulation or heat insulation between them. It is a body, and is appropriately arranged in a layered manner at the opposing portions of the module base 2 and the nested module 3.
The material of the heat insulating member 5 is made of a material having a lower thermal conductivity than the module base 2 and the nested module 3.
In this embodiment, it is made of a synthetic resin that also serves as an adhesive for fixing the nesting module 3 to the module base 2. As shown in FIGS. 1 (b) and 2, the inner surfaces of the side walls 2d and 2d have a thickness T. It is provided so as to substantially cover the side.
The thickness T is set to such a thickness that the necessary thermal insulation can be obtained according to the material of the thermal insulating member 5, the thermal conductivity, and the heat generation amount of the light emitting device. However, when it is necessary to provide electrical insulation between the module base 2 and the nested module 3, it is set so as to satisfy the required electrical insulation.

The nested modules 3 and 3 are members for radiating the light emitting devices 4B and 4D and supporting the light emitting devices 4A and 4C in a positional relationship adjacent to each other. Be placed.
The material of the nested module 3 can be the same material as that of the module base 2.
In this embodiment, it is a rectangular flat plate having a thickness D.
On the upper surface of the nested module 3, a light emitting device arrangement surface 3a on which the light emitting device 4B (4D) is arranged is formed. In the present embodiment, the area of the light emitting device arrangement surface 3a is set to be larger than the light emitting devices 4B and 4D. And the surface state of each light emitting device arrangement | positioning surface 3a is set similarly to the light emitting device arrangement | positioning surface 2a.

  As shown in FIG. 2, the nested modules 3 and 3 are arranged in the respective through-hole portions 2 </ b> B so that the respective light emitting device arrangement surfaces 3 a and 3 a face the center side of the module base 2. It is being fixed to the side wall 2d on both sides.

With such a configuration, the light emitting device arrangement surfaces 2a and 3a are aligned at the same height.
In plan view, the light emitting devices 4A and 4B and the light emitting devices 4D and 4C are arranged adjacent to each other in the width direction of the width W, and correspond to the distance between the convex side surface 2b and the nested module side surface 3e in the width W direction. to ambient atmosphere layer 6 made of the gap width d _w is formed along the height direction.
The light emitting device 4A, 4D and light emitting devices 4B, 4C are arranged adjacent via the surrounding atmosphere layer 6 of the gap width d _H Similarly to the width H direction.
The widths d _W and d _H of the ambient atmosphere layer 6 satisfy the electrical insulation characteristics of the atmosphere gas, for example, air or inert gas, and are thermally applied to adjacent light emitting devices by the heat transfer of the atmosphere gas. Under conditions where the influence is within an allowable range, the smallest possible value is adopted, and d _W <W and d _H <H are satisfied. For this reason, the adjacent distances of the light emitting devices are sufficiently small and are arranged at positions close to each other.

With such a configuration, the nested modules 3 and 3 are substantially insulated from each other through the heat insulating member 5, and the nested modules 3 and 3 constitute an independent heat dissipation base.
Further, the heat transfer path from the nested module side surface 3 e is also substantially insulated by the ambient atmosphere layer 6.

Therefore, the heat generated in the light emitting device 4B (4D) is thermally conducted to the nested module 3 through the light emitting device arrangement surface 3a, and is radiated from the bottom surface facing the light emitting device arrangement surface 3a. That is, the module base 2 is not substantially thermally conducted, and the influence of heat transfer from the surface of the nested module 3 is suppressed by the ambient atmosphere layer 6.
Therefore, by setting the heat dissipation characteristics of the nested module 3 as appropriate, the thermal influence can be reduced even if it is disposed in the vicinity of another light emitting device. As a result, it is possible to suppress the temperature rise of the light emitting device 4B (4D), and to reduce the luminance decrease and the life deterioration.

On the other hand, in the module base 2 on which the light emitting devices 4A and 4C are arranged, the heat conduction path and the heat transfer path for the nested modules 3 and 3 are substantially insulated via the heat insulating member 5 and the ambient atmosphere layer 6.
Since the convex portions 2A and 2A are continuous by the side wall 2d, a continuous heat conduction path is formed, but since the heat conduction path is long, the mutual thermal influence is reduced.
For this reason, the heat generated in the light emitting device 4A (4C) is thermally conducted to the convex portion 2A via the light emitting device arrangement surface 2a, and is radiated from the bottom surface facing the light emitting device arrangement surface 2a. In addition, the influence of heat transfer from the heat radiating surface is suppressed by the ambient atmosphere layer 6.
For this reason, by appropriately setting the heat dissipation characteristics of the convex portion 2A, the thermal influence can be reduced even when the convex portion 2A is disposed in the vicinity of another light emitting device. As a result, it is possible to suppress the temperature rise of the light emitting device 4A (4C), and to reduce luminance reduction and lifetime deterioration.
That is, in the module base 2, even if the light emitting devices 4A and 4C are spatially close to each other, a state where they are thermally separated is formed.

Thus, in the light emitting device module 1, since the thermal independence of each light emitting device is substantially maintained, the type of the light emitting device at the position of the light emitting device arrangement surfaces 2a, 2a, 3a, 3a is not particularly limited. For example, as shown in FIG. 3A, a red light emitting device R, a green light emitting device G, a blue light emitting device B, and a green light emitting device G are provided as the light emitting devices 4A, 4B, 4C, and 4D, respectively. Or a green light emitting device G, for example, may be provided for all of the same color as shown in FIG. Further, as shown in FIG. 3C, a red light emitting device R, a blue light emitting device B, a red light emitting device R, and a blue light emitting device B are provided as the light emitting devices 4A, 4B, 4C, and 4D to emit two-color light. You may be able to do it.
However, since the nest modules 3 have higher thermal insulation with respect to the other than the projections 2A of the module base 2, if there are two light emitting devices that emit light at different timings, the nest module 3 It is preferable to arrange in. In this case, when the light is turned off, the thermal influence from other light emitting devices hardly affects, so that better performance can be obtained.
For example, although not particularly illustrated, when the red light emitting device R, the green light emitting device G, and the blue light emitting device B are sequentially turned on and used for displaying color separation images, the light emitting devices 4A, 4B, 4C, and 4D are used. When the green light emitting device G, the red light emitting device R, the green light emitting device G, and the blue light emitting device B are provided, the green light emitting devices G and G that always emit light at the same timing are disposed on the module base 2. Even if slight heat conduction occurs between the portions 2A and 2A, it is preferable because the thermal insulation is maintained between the three colors.

In the present embodiment, the adjacent intervals d _W and d _H of adjacent light emitting devices are arranged close to each other so as to be smaller than W and H, respectively. For example, when a plurality of light emitting devices are condensed by a common optical system Since the light can be emitted from the vicinity of the optical axis, there is an advantage that it is possible to form a light source that is excellent in light utilization efficiency and has reduced aberration deterioration and color unevenness in the case of color light.

Thus, in this embodiment, the said heat-transfer restriction | limiting part becomes a structure provided with the thermal insulator which consists of a material whose heat conductivity is lower than the said thermal radiation base part.
In this case, heat transfer by heat conduction can be regulated.
Moreover, in this embodiment, the said heat-transfer restriction | limiting part becomes a structure provided with an ambient atmosphere layer by providing the clearance gap which enables circulation of ambient atmosphere in the adjacent part of the said thermal radiation base part.
In this case, heat transfer by heat transfer by the ambient atmosphere can be regulated. In addition, heat dissipation can be promoted when the circulation of the ambient atmosphere is high.

[Second Embodiment]
A light emitting device module according to a second embodiment of the present invention will be described.
FIG. 4A is a plan view showing a schematic configuration of the light emitting device module according to the second embodiment of the present invention. FIG. 4B is a BB cross-sectional view of FIG.

  As shown in FIGS. 4A and 4B, the light emitting device module 50 of the present embodiment includes four heat dissipating bases 9 instead of the module base 2 and the nested module 3 of the first embodiment. Is supported on the heat dissipation base holding member 8 with the heat conductive member 15 having good heat conductivity interposed therebetween. Hereinafter, a description will be given focusing on differences from the above embodiment.

The heat dissipation base holding member 8 is a plate-like member, and when the light emitting devices 4A, 4B, 4C, and 4D are arranged in the same positional relationship as in the first embodiment, the four heat dissipation bases 9 are separated from each other by a gap d. _W or d _H can be provided and arranged.
The material of the heat dissipation base holding member 8 is not particularly limited either thermally or electrically.

The heat radiating base 9 has a light emitting device arrangement surface 9a having an area which is equal to or slightly larger than the light emitting surface of the light emitting device 4A (4B, 4C, 4D) in plan view on the upper surface side, and has a block having four side surfaces 9c It is a heat dissipation member. And the lower surface 9b which is an opposing surface of the light emitting device arrangement surface 2a is arranged in contact with the heat conductive member 15.
Therefore, between the adjacent heat dissipation bases 9, as in the first embodiment, each ambient atmosphere layer 6 having gaps d _W and d _H is formed.
The material of the heat dissipation base 9 can be the same material as that of the module base 2 and the nested module 3 of the first embodiment.
The heat conductive member 15 may be an adhesive that adheres the heat dissipation base 9 to the heat dissipation base holding member 8.

  According to such a light emitting device module 50, the heat of each light emitting device is radiated from the bottom surface 9 b facing the light emitting device arrangement surface 9 a of the heat dissipation base 9. On the other hand, since each heat dissipation base 9 is substantially insulated from the adjacent heat dissipation base 9 by the ambient atmosphere layer 6, the mutual thermal influence is reduced. In addition, each heat dissipation base 9 is formed with a heat conduction path via the heat conductive member 15 and the heat dissipation base holding member 8, but a long path is formed to reduce the thermal influence, and the heat dissipation base 9 Since heat is efficiently radiated from the heat conductive member 15 and the heat radiating base holding member 8, the thermal independence is substantially ensured substantially.

[Third Embodiment]
A light emitting device module according to a third embodiment of the present invention will be described.
FIG. 5A is a plan view showing a schematic configuration of a light emitting device module according to the third embodiment of the present invention. FIG.5 (b) is CC sectional drawing of Fig.5 (a).

  As shown in FIGS. 5A and 5B, the light emitting device module 60 of the present embodiment includes a module base 11 in place of the module base 2 and the nested module 3 of the first embodiment. Hereinafter, a description will be given focusing on differences from the above embodiment.

The module base 11 has an area of (2 · H + d _H ) × (2 · W + d _W ), for example, in plan view, and divides the upper surface into four equal parts into a block-shaped member having a height D _3. By providing a groove of _{W 4} , d _H , and depth D ₄ (where D ₄ <D ₃ ), a rectangular parallelepiped heat radiation block 11 A is formed on the plate-shaped bottom 11 E having a height (D ₃ -D ₄ ). , 11B, 11C, and 11D.
A light emitting device arrangement surface 11a for arranging the light emitting devices 4A, 4B, 4C, and 4D is formed on the upper surface side of the heat radiation block portions 11A, 11B, 11C, and 11D, respectively.
The arrangement positions of the light emitting devices are the same as those in the first embodiment.
And in the groove | channel which divides | segments these heat radiation block parts, the heat insulation member 5 is provided over a part or all of a groove | channel. The configuration of the heat insulating member 5 can employ the same configuration as in the first embodiment.
The material of the module base 11 is made of the same material as that of the module base 2, and the light emitting device placement surface 11a is formed on the same surface as the light emitting device placement surface 2a.

According to such a light emitting device module 60, the heat of each light emitting device conducts heat through the heat radiating block portions 11 </ b> A, 11 </ b> B, 11 </ b> C, and 11 </ b> D and is radiated from the outer peripheral portion and the bottom surface of the module base 11. In that case, since the heat conduction path between the adjacent heat radiation block portions in the range where the heat insulating member 5 is provided is substantially insulated, direct heat transfer is suppressed.
Therefore, by appropriately setting the heat radiation from the outer peripheral portion and the bottom surface, it is possible to ensure the thermal insulation between the heat radiation block portions 11A, 11B, 11C, and 11D by reducing the heat conduction at the bottom portion 11E. .
That is, in this configuration, as in the case of the module base 2 of the first embodiment, by extending the heat conduction path, a state of being substantially thermally insulated is formed.
In this embodiment, since the heat insulation member 5 is disposed in the groove between the heat dissipation block portions instead of the ambient atmosphere layer 6, the heat insulation is improved compared to the first embodiment. is there.

  In the above description, the example in which one light emitting device is arranged in the heat dissipation base is described, but at least one of the light emitting devices may be arranged. For example, when a light emitting device that is turned on at the same time generates a small amount of heat, the plurality of light emitting devices may be arranged on one heat radiating base.

  In the above description, an example in which there are four light emitting devices has been described. However, the number of light emitting devices is not limited to this, and any number of light emitting devices may be used as long as it is two or more.

In the above description, the ambient atmosphere means the ambient atmosphere closest to the light emitting device and the heat dissipation base. Therefore, the light emitting device module may be covered and packaged with a light transmissive resin.
Moreover, such resin may be directly formed on the light emitting device. However, the thermal insulation between the heat dissipation surface facing the adjacent heat dissipation base is maintained.
In these cases, heat from the heat radiating surface other than the light radiating device and the heat radiating surface opposite to the adjacent heat radiating base is dissipated into the package or thermally conducted through the resin of the package, and finally radiated to the outside. Is done. Alternatively, when the thermal conductivity of such a resin is poor, the heat radiating base portion is thermally conducted and then radiated from the heat radiating surface.

  Further, the constituent elements described in each of the above embodiments can be appropriately combined and implemented within the scope of the technical idea of the present invention, if technically possible. For example, in the second embodiment, the example in which the heat transfer restriction portion is composed only of the ambient atmosphere layer has been described. However, for example, instead of the ambient atmosphere layer 6, the heat insulating member 5 is adopted or used together. You can also. Alternatively, if necessary, the heat insulating member 5 may be provided instead of the heat conductive member 15.

Here, a case will be described where the names of the correspondence relationships between the terms of the above embodiments and the terms of the claims are different.
The red light emitting device R, the green light emitting device G, and the blue light emitting device B are one embodiment of the light emitting device. The convex portions 2A, 3A, the heat dissipation base 9, and the heat dissipation block portions 11A, 11B, 11C, 11D are an embodiment of the heat dissipation base portion. The thermal insulation member 5 is an embodiment in which the heat transfer restriction portion is implemented as a thermal insulator. The ambient atmosphere layer 6 is an embodiment of the heat transfer restriction unit.

It is the top view which shows schematic structure of the light-emitting device module which concerns on the 1st Embodiment of this invention, and its AA sectional drawing. 1 is an exploded perspective view of a light emitting device module according to a first embodiment of the present invention. It is a top view which shows the example of arrangement | positioning of the light emitting device in the 1st Embodiment of this invention. It is the top view which shows schematic structure of the light-emitting device module which concerns on the 2nd Embodiment of this invention, and its BB sectional drawing. It is the top view which shows schematic structure of the light emitting device module which concerns on the 3rd Embodiment of this invention, and its CC sectional drawing.

Explanation of symbols

1, 50, 60 Light emitting device module 2, 11 Module base 2a, 3a, 9a, 11a Light emitting device arrangement surface 2b, 3b Convex side surface 2A Convex part (heat dissipation base part)
2B Through-hole part 3 Nested module 3e Nested module side face 4A, 4B, 4C, 4D Light-emitting device 5 Thermal insulation member (heat-transfer regulation part)
6 Ambient atmosphere layer (heat transfer regulation part)
9 Heat dissipation base (heat dissipation base)
11A, 11B, 11C, 11D Heat dissipation block (heat dissipation base)
11E Bottom R Red light emitting device (light emitting device)
G Green light emitting device (light emitting device)
B Blue light emitting device (light emitting device)

Claims (3)

A plurality of light emitting devices arranged adjacent to a position close to the size of the light emitting surface;
A plurality of divided heat dissipation bases that support at least one of the plurality of light emitting devices;
A light emitting device module comprising: a heat transfer restricting portion that restricts heat transfer between the plurality of heat dissipating base portions.   The light-emitting device module according to claim 1, wherein the heat transfer restriction part includes a thermal insulator made of a material having a lower thermal conductivity than the heat dissipation base part.   3. The light emitting device module according to claim 1, wherein the heat transfer restriction portion includes an ambient atmosphere layer by providing a gap that allows the ambient atmosphere to flow in an adjacent portion of the heat dissipation base portion.

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