JP2011044612A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve efficiency of light emission and reliability by equalizing temperature distribution of a light emitting element group, in a light emitting device including the light emitting element group provided by densely mounting a plurality of light emitting elements. <P>SOLUTION: The light emitting device 1 includes a mounting substrate 2 mounted with a plurality of light emitting elements 4, a wiring pattern 3 on an element-mounting surface 21 of the mounting substrate, thermal vias 7, and a heat dissipation pattern 8 crossing thereto. The light emitting element group 40 includes a center group 41 and a peripheral group 42, and the thermal vias 7 includes center vias 7a and peripheral vias 7b. The heat dissipation pattern 8 includes a center-side heat dissipation pattern 8a and a periphery-side heat dissipation pattern 8b connected to the center vias 7a and the peripheral vias 7b, respectively, and the center vias 7a and the center-side heat dissipation pattern 8a are prevented from getting contact with the peripheral vias 7b and the periphery-side heat dissipation pattern 8b. Thereby heat from the peripheral group 42 is not led to the center group 41, reaching high temperature of the center group 41 is prevented, temperature distribution of the light emitting element group 40 can be uniformized, and the efficiency of light emission and reliability are improved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a heat dissipation structure of a light emitting element group in a light emitting device having a light emitting element group in which a plurality of light emitting elements are densely mounted.

  2. Description of the Related Art Conventionally, a light-emitting device that is mounted at a high density by connecting a plurality of light-emitting elements in series and mounted on a mounting substrate is known (see, for example, Patent Document 1). In such a light-emitting device, as shown in FIGS. 10A and 10B, a plurality of light-emitting elements 101 are arranged close to each other, and an element group P in the central part of the light-emitting element group includes peripheral elements. Since it is affected by heat from the group Q as indicated by an arrow, the temperature distribution of the light emitting element group becomes high at the center. At this time, as shown in FIG. 10C, the temperature distribution of the mounting substrate 100 is similar to the temperature distribution of the light emitting element group. For this reason, the element group at the center of the light emitting element group is likely to be deteriorated due to a high temperature, the light emission efficiency, reliability, and lifetime are lowered, and the light emission efficiency and reliability of the device itself are also lowered.

  Incidentally, as a mounting substrate that improves heat dissipation from the light emitting element, it is known to provide a heat transfer member for heat dissipation in the mounting substrate as shown in FIG. 11 (see, for example, Patent Document 2). In this mounting substrate 100, one light emitting element 101 is mounted in a cavity 110 formed by opening a surface of a substrate body 102 formed by laminating a plurality of insulating layers 103, and a plurality of heat transfer parallel to the insulating layer 103. A conductor layer 104 and a heat transfer via conductor 105 in contact with the heat transfer conductor layer 104 are provided, and heat from the light emitting element 101 is dissipated through the heat transfer via conductor 105 to the inside of the substrate body 102. Improved heat dissipation.

  However, the mounting substrate 100 mounts one light emitting element 101 in the cavity 110, and the heat dissipation of each light emitting element 101 is improved. However, using the mounting substrate 100, a plurality of light emitting elements 101 are mounted. When placed close to each other, when viewed as a whole of the light emitting element group, the temperature distribution of the light emitting element group is not uniform as described above, and the temperature of the light emitting element in the central part becomes high due to the heat from the peripheral part. Emission efficiency, reliability, and lifetime are likely to be reduced.

JP 2007-31398 A JP 2008-294253 A

  The present invention solves the above problem, and in a light-emitting device having a light-emitting element group in which a plurality of light-emitting elements are densely mounted, the temperature distribution of the light-emitting element group is made uniform, and luminous efficiency and reliability are improved. An object of the present invention is to provide a light-emitting device that can be used.

  In order to achieve the above object, the invention of claim 1 includes a mounting substrate, a wiring pattern provided on or inside the mounting substrate, and a light emitting element group composed of a plurality of light emitting elements mounted on the wiring pattern, A thermal via provided at least partially in the mounting substrate in a direction perpendicular to the device mounting surface for dissipating heat from the light emitting element, and in the mounting substrate. A heat dissipating pattern provided in a direction parallel to the element mounting surface and intersecting with the thermal via, and the light emitting element group includes a central group located in a central portion of the light emitting element group, and a periphery of the central group The thermal via has a central thermal via corresponding to the central group and a peripheral thermal via corresponding to the peripheral group, and the heat dissipation pattern is A central-side heat dissipation pattern connected to the central-side thermal via, and a peripheral-side heat dissipation pattern connected to the peripheral-side thermal via, the central-side thermal via and the central-side heat dissipation pattern, and the peripheral-side thermal via And the peripheral side heat radiation pattern are configured not to contact each other.

  According to a second aspect of the present invention, in the light emitting device according to the first aspect, in the mounting substrate, the central side heat radiation pattern and the central side thermal via have a gap with the peripheral side heat radiation pattern and the peripheral side thermal via. The center-side heat dissipation pattern is provided so as to extend toward the peripheral side and increase in pattern area as the distance from the element mounting surface of the mounting substrate increases in the vertical direction while maintaining the gap. is there.

  According to a third aspect of the present invention, in the light emitting device according to the first or second aspect, the via located at a position not in contact with the wiring pattern is extended toward the surface of the mounting substrate, and the surface side of the mounting substrate It is exposed to.

  According to a fourth aspect of the present invention, in the light emitting device according to any one of the first to third aspects, at least two of the thermal vias are respectively energized to the light emitting element through the mounting substrate. The conduction vias are connected to the positive electrode portion and the negative electrode portion of the wiring pattern to which the positive and negative electrodes of the light emitting element are connected, respectively.

  According to a fifth aspect of the present invention, in a configuration in which a plurality of mounting boards on which the light emitting element groups are densely mounted are densely mounted on a wiring board, the central group and the peripheral group in the entire light emitting element group are claimed. The thermal via and the heat radiation pattern satisfying any one of claims 1 to 4 are provided.

  According to the first aspect of the present invention, the peripheral-side thermal via and the peripheral-side heat dissipation pattern, and the central-side thermal via and the central-side heat dissipation pattern are suppressed from mutual heat transfer and easily separated from each other. Of the element groups, the heat from the peripheral group is less likely to be directed to the central group, the central group is prevented from becoming hot, the temperature difference between each element group can be reduced, and heat dissipation is promoted throughout the device. The For this reason, deterioration due to high temperature of the light emitting element can be suppressed, and light emission efficiency and reliability can be improved.

  According to the second aspect of the present invention, the heat radiation from the central element group is further promoted because the center side heat radiation pattern radiates heat in the parallel direction as the distance from the element mounting surface of the mounting substrate increases in the vertical direction.

  According to the invention of claim 3, since the thermal via can be exposed while maintaining the insulation with the wiring pattern and the length thereof can be made longer, the heat radiation surface can be widened and the heat radiation of the light emitting element can be promoted.

  According to the invention of claim 4, the thermal via can be used also as the energizing via, and the light emitting element can be energized from the side opposite to the element mounting surface of the mounting substrate via the energizing via. When power is supplied through the board, the power supply pattern on the wiring board and each electrode part on the wiring pattern on the mounting board can be connected via the current via without using wire bonding, and the structure is simplified. .

  According to the invention of claim 5, since the temperature of the central group of the whole light emitting element group mounted on a plurality of mounting boards can be reduced and the whole temperature can be averaged, the luminous efficiency and reliability can be improved. Can be increased.

1 is a plan view of a light emitting device according to a first embodiment of the present invention. FIG. 6 shows an arrangement of light emitting element groups of the light emitting device. The top view of the mounting substrate of the light-emitting device. (A) is sectional drawing of the light-emitting device, (b) is a figure which shows the example of the thermal radiation pattern in the mounting substrate. Sectional drawing with which the thermal radiation pattern of the light-emitting device was deform | transformed. Sectional drawing of the light-emitting device which concerns on the 2nd Embodiment of this invention. Sectional drawing of the light-emitting device which concerns on the 3rd Embodiment of this invention. The figure which shows the example of a pattern of the wiring board which arranges the mounting substrate of the light-emitting device in series. The top view of the light-emitting device which concerns on the 4th Embodiment of this invention. (A) is a top view of the mounting board | substrate of the conventional light-emitting device, (b) is a figure for demonstrating the temperature distribution of the light emitting element group on the mounting board | substrate, (c) demonstrates the temperature distribution of the mounting board | substrate. Figure for. Sectional drawing of the mounting board | substrate in the other conventional light-emitting device.

  Hereinafter, a light-emitting device according to a first embodiment of the present invention will be described with reference to FIGS. 1 shows the configuration of the light emitting device 1 of the present embodiment, FIG. 2 shows the arrangement configuration of the light emitting element group 40 of the light emitting device 1, and FIG. 3 shows the wiring pattern 3 on the mounting substrate 2 of the light emitting device 1. The light emitting device 1 includes an insulating mounting substrate 2, a wiring pattern 3 mounted on the element mounting surface 21 of the mounting substrate 2, and a plurality (18 in this case) of light emitting elements mounted on the wiring pattern 3. 4, a frame-like wiring board 5 for supplying power to the light emitting element 4, and a heat radiating plate 6 that radiates heat from the mounting board 2 and the wiring board 5. The mounting board 2 and the wiring board 5 are mounted on the heat sink 6.

  The mounting substrate 2 has an insulating substrate such as ceramic having a rectangular shape in plan view, the light emitting element 4 is mounted on the element mounting surface 21 on the surface, and the heat from the light emitting element 4 is dissipated inside the substrate. It has a thermal via 7 and a heat radiation pattern 8 (see FIG. 4 described later) made of a high heat conductive member. The mounting substrate 2 may use an insulating resin member (epoxy, glass epoxy, etc.) or may have a shape other than a rectangle.

  The wiring pattern 3 is arranged so as to connect a plurality of light emitting elements 4 in series, and a plurality of pedestals for connecting the positive and negative electrode portions 31 and 32 supplied with power and the individual light emitting elements 4 in series. A pattern 33 and a line pattern 34 for connecting them in series are provided. The positive and negative electrode portions 31 and 32 are the head portion and the rear portion of the pattern in which the base pattern 33 and the line pattern 34 are connected in series. The positive and negative electrode portions 31 and 32 are connected to the power supply wiring pattern 51 of the wiring board 5 by bonding wires L1, and the power supply wiring pattern 51 is connected to a power supply portion (not shown) by wiring wires. Note that the wiring pattern 3 can be provided inside the mounting substrate 2, and the light emitting element 4 may be arranged in parallel or in combination of series and parallel in addition to the series.

  As shown in FIG. 2, the light emitting element group 40 includes a central group 41 located in the central part thereof and a peripheral group 42 arranged in the periphery thereof. Here, the two light emitting elements 4 in the central part are provided. Constitutes a central group 41, and 16 light emitting elements 4 located in the periphery thereof constitute a peripheral group 42.

  The light emitting element 4 is composed of a flat light emitting element of about 0.4 to 1 mm square using an LED, an organic EL, or the like, and has a junction terminal portion 43 serving as the positive and negative electrodes. The joint terminal portion 43 is arranged between the positive electrode portion 31 and the pedestal pattern 33 and between the pedestal patterns 33 so that the polarity corresponds to the arrangement of the wiring pattern 3 from the positive electrode portion 31 to the negative electrode portion 32. Between the pedestal pattern 33 and the line pattern 34, and between the pedestal pattern 33 and the negative electrode portion 32. Here, the light-emitting element 4 is flip-chip mounted with gold (Au) bumps or the like, but may be face-up mounted on the element surface using wire bonding. The central group 41 may include only one light emitting element 4.

  4A shows a cross-sectional configuration of the light emitting device 1, and FIG. 4B shows an example of the heat radiation pattern 8 formed inside the mounting substrate 2 (here, on the insulating layer 24 in FIG. 4A). Pattern). The mounting substrate 2 is made of an insulating substrate formed by integrally laminating a plurality of ceramic insulating layers 22 to 28, and has a thickness of about 0.3 to 1.0 mm. The thicknesses of the insulating layers 22 to 28 may be the same as or different from each other. As the ceramic member, alumina ceramic, glass-alumina mixed glass ceramic, or the like can be used.

  The mounting substrate 2 includes a plurality of thermal vias 7 that are provided in a bar shape in a direction perpendicular to the element mounting surface 21, a plurality of planar heat radiation patterns 8 that intersect with the thermal vias 7, and a side opposite to the element mounting surface 21. The board | substrate junction part 9 provided is provided, and the thermal via 7 and the thermal radiation pattern 8 are thermally connected. The thermal via 7 penetrates through a plurality of layers of the insulating layers 22 to 28 of the mounting substrate 2, and the lower end portion is connected to the substrate bonding portion 9. The heat dissipation pattern 8 is formed in five layers between the insulating layers 23 to 28 of the mounting substrate 2 and is provided in a direction parallel to the element mounting surface 21 of the mounting substrate 2. The substrate bonding portion 9 is bonded to the wiring substrate 5 or the heat sink 6. Note that the thermal via 7 and the heat dissipation pattern 8 may not be partially continuous in the vertical direction and the parallel direction of the element mounting surface 21, respectively.

  The thermal via 7 includes a central thermal via (hereinafter referred to as a central via) 7 a corresponding to the central group 41 and a peripheral thermal via (hereinafter referred to as a peripheral via) 7 b corresponding to the peripheral group 42. The heat dissipation pattern 8 has a central heat dissipation pattern 8a connected to the central via 7a and a peripheral heat dissipation pattern 8b connected to the peripheral via 7b.

  The thermal via 7 extends to the vicinity of the element mounting surface 21 of the mounting substrate 2, but is not in contact with the wiring pattern 3. Further, the upper end of the thermal via 7 is provided closer to the element mounting surface 21 of the mounting board 2 than the uppermost heat radiation pattern 8. Further, each thermal via 7 does not have to be connected at all to the substrate bonding portion 9 at its lower end.

  Among the thermal vias 7, those that are not in contact with the wiring pattern 3 when the upper end portion is extended are extended toward the element mounting surface 21, and the elements of the mounting substrate 2, like the thermal vias 7 a 1 and 7 b 1. It is exposed on the mounting surface 21 side. In this way, the thermal vias 7a1 and 7b1 that are not in contact with the wiring pattern 3 are exposed while maintaining insulation from the wiring pattern 3, and the length thereof can be made longer. 4 heat dissipation can be promoted. Note that it is not necessary to expose the entire upper end portion of the thermal via 7 to the element mounting surface 21 side. Further, the thermal via 7 may have a plate shape other than the rod shape, and the thickness or thickness thereof may be the same or different from each other.

  The central via 7a and the central side heat radiation pattern 8a, and the peripheral via 7b and the peripheral side heat radiation pattern 8b are configured not to contact each other. At this time, the distance between the central via 7a and the central side heat radiation pattern 8a and the peripheral via 7b and the peripheral side heat radiation pattern 8b is maintained at a distance that does not cause dielectric breakdown. For example, when the substrate material is general alumina, the dielectric breakdown voltage is 10 V / μm, and it is preferable that there is a distance of about 5 μm or more.

  Here, on the paper surface of FIG. 4A, the peripheral vias 7b on the left and right of the central via 7a are arranged substantially symmetrically with respect to the central position of the central via 7a, and are given to the central via 7a of the peripheral vias 7b. The effect of temperature is the same.

  The substrate bonding portion 9 is made of a metal pattern that forms the back surface wiring pattern or the back surface heat radiation pattern of the mounting substrate 2 and is bonded to the heat radiation plate 6 with an adhesive having good thermal conductivity. Further, the wiring board 5 has a heat radiation plate joining pattern 52 for joining to the heat sink 6, and is joined to the heat sink 6 at this portion. The heat sink 6 may be a metal plate with good heat dissipation. The thermal via 7, the heat radiation pattern 8, and the substrate bonding portion 9 are made of high thermal conductive members such as Ag, Au, Cu, and Ni.

  The manufacturing method of the mounting substrate 2 will be described. For example, as an insulating layer made of a ceramic member, green sheets 22 to 28 are formed using low-temperature firing or high-temperature firing ceramics, and through holes are provided in these green sheets. An unfired thermal via 7 is formed by filling the through hole with a conductive paste containing Ag powder. Next, a conductive paste is printed on the surface of the green sheet to form an unfired heat dissipation pattern 8, and the green sheets 22 to 28 on which the thermal vias 7 and the heat dissipation pattern 8 are formed are stacked and pressure-bonded. The mounted substrate 2 is formed by firing the fired laminate. Thereafter, the wiring pattern 3 on the element mounting surface 21 of the mounting substrate 2 is plated (for example, Ag, Ni, Au plating). Here, the diameter of the conductor of the thermal via 7 is about 0.1 to 0.3 mm, and the thickness of the heat radiation pattern 8 is about 0.05 to 0.3 μm.

  Here, as a modified configuration of the heat radiation pattern 8, a configuration in which the heat radiation pattern 8 at the top is arranged at the upper end of the thermal via 7 inside the mounting substrate 2 is shown in FIG. 5. In this modification, the uppermost heat radiation pattern 8 is provided in a region close to the element mounting surface 21 of the mounting substrate 2, so that heat from the light emitting element group 40 is received over a wide range to the thermal via 7. Heat can be transferred.

  According to the light emitting device 1 of the present embodiment, the peripheral via 7b and the peripheral heat dissipation pattern 8b, and the central via 7a and the central heat dissipation pattern 8a are suppressed from heat transfer to each other and easily separated thermally. Therefore, in the light emitting element group 40, the heat from the peripheral group 42 is difficult to be guided to the central group 41, the high temperature of the central group 41 can be suppressed, and the temperature difference between each element group can be reduced. Overall heat dissipation is promoted. For this reason, the deterioration by the high temperature of the light emitting element 4 is suppressed, and luminous efficiency and reliability can be improved.

  Next, a light emitting device according to a second embodiment of the present invention will be described with reference to FIG. In the light emitting device 1 of the present embodiment, a gap 71 is provided between the central side heat radiation pattern 8a and the central via 7a and the peripheral side heat radiation pattern 8b and the peripheral via 7b on the mounting substrate 2. The center-side heat radiation pattern 8a is configured to extend toward the peripheral side and increase in pattern area as the distance from the element mounting surface 21 of the mounting board 2 increases in the vertical direction while holding the gap 71. Further, the number of the central vias 7a is increased in accordance with the expansion of the central side heat radiation pattern 8a.

  The area of the center side heat radiation pattern 8a gradually expands in a hierarchy in a direction parallel to the element mounting surface 21 from the element mounting surface 21 of the mounting substrate 2 toward the substrate bonding portion 9. Here, the peripheral side heat radiation pattern 8b and the peripheral via 7b are sequentially moved in the peripheral direction in order to avoid contact with the enlarged central side heat radiation pattern 8a, and a part of the peripheral via 7b is on the substrate bonding portion 9 side. The gap 71 is cut short and has a substantially stepped mountain shape. Thereby, since the heat from the center side heat radiation pattern 8a is more widely transmitted to the board | substrate junction part 9, heat dissipation from the center group 41 is further accelerated | stimulated, and luminous efficiency and reliability improve more.

  The peripheral side heat radiation pattern 8b and the peripheral via 7b are configured such that the pattern area is increased in the peripheral direction and the number of vias is increased, so that the heat radiation from the peripheral group 42 is not reduced. Yes. Here, the thermal via 7 b 1 is not connected to the substrate bonding portion 9.

  Next, a light-emitting device according to a third embodiment of the present invention will be described with reference to FIG. The light emitting device 1 of this embodiment is different from the above embodiment in the configuration of the peripheral via 7b and the peripheral heat radiation pattern 8b, and the configuration of the mounting substrate 2 and the wiring substrate 5. That is, at least two of the peripheral vias 7 b are energized vias 72 and 73 that respectively penetrate the mounting substrate 2, and these energized vias 72 and 73 are connected to the positive electrode portion 31 and the negative electrode portion 32 of the wiring pattern 3. Each is connected.

  The wiring board 5 is bonded onto the heat sink 6, and the mounting board 2 is mounted on the wiring board 5. The power supply wiring pattern 51 of the wiring board 5 includes a positive power supply wiring pattern 51a to which positive and negative voltages are supplied, and a negative power supply wiring pattern 51b. Further, the metal pattern of the substrate bonding portion 9 is separated into a positive electrode bonding pattern 91 and a negative electrode bonding pattern 92. The positive electrode bonding pattern 91 and the negative electrode bonding pattern 92 are bonded to the positive power supply wiring pattern 51a and the negative power supply wiring pattern 51b of the wiring board 5, respectively. A distance of about 20 μm or more is provided between the positive electrode bonding pattern 91 and the negative electrode bonding pattern 92.

  The current-carrying via 72 is a through-hole formed on the substrate junction 9 near the positive electrode portion 31 on the outermost peripheral side (here, the leftmost side) of the two peripheral vias 7b located on the left and right of the central via 7a. Consists of vias. In addition, both ends of the via are connected to the positive electrode portion 31 and the positive electrode bonding pattern 91, respectively.

  The current-carrying via 73 is away from the most peripheral side (rightmost side) of the peripheral via 7b and is formed from a through via formed on the substrate bonding portion 9 close to the negative electrode portion 32 so as not to contact the peripheral-side heat radiation pattern 8b. Become. Both ends of the via are connected to the negative electrode portion 32 and the negative electrode bonding pattern 92, respectively. The peripheral via 7 b is electrically connected to the wiring pattern 3 and the substrate bonding portion 9, but may be floated without contact.

  In the configuration as described above, it is possible to employ a state in which a plurality of mounting boards 2 are provided side by side on the wiring board 5 and are electrically connected in series. An example of the configuration of the wiring board 5 in that case is shown in FIG. The wiring board 5 has a power wiring pattern 51 configured to mount a plurality of mounting boards 2, and the power wiring pattern 51 is a pattern in which positive and negative power wiring patterns 51a and 51b are alternately repeated in series. ing. The plurality of mounting boards 2 have their positive and negative electrode bonding patterns 91 and 92 sequentially attached to the positive and negative power supply wiring patterns 51 a and 51 b of the wiring board 5 and connected in series.

  According to the light emitting device 1 of the present embodiment, the light emitting element 4 can be energized from the substrate bonding portion 9 on the back surface side of the mounting substrate 2 by the energization vias 72 and 73. Therefore, the thermal via 7 can also be used as the energizing vias 72 and 73. That is, the thermal via 7 and the heat radiation pattern 8 separated in the mounting substrate are used not only as a heat radiation path but also as an energization path. Thereby, when power is supplied to the light emitting element 4 from the wiring board 5, the electrical connection between the power supply wiring pattern 51 on the wiring board 5 and the electrode portions 31 and 32 on the wiring pattern 3 can be made without using wire bonding. And can be connected via the current-carrying vias 72 and 73, and the structure is simplified.

  Next, a light emitting device according to a fourth embodiment of the present invention will be described with reference to FIG. In the light emitting device 1 of the present embodiment, a plurality of mounting boards 2a, 2b, 2c, and 2d on which the light emitting element groups 40 are densely mounted are densely mounted on each other, and are densely mounted on the central portion of the wiring board 5. A group of substrates is formed. A group of the light emitting element groups 40 in the mounting substrate group is referred to as an all light emitting element group (corresponding to the entire light emitting element group in the claims), and the light emission located at the center of the mounting substrate group of the all light emitting element groups. A set of elements 4 is referred to as an all-central group (corresponding to a central group in the claims) A, and a set of light-emitting elements 4 located in the periphery thereof is referred to as an all-peripheral group (corresponding to a peripheral group in the claims) B. In the present embodiment, all the central groups A and all peripheral groups B of all the light emitting element groups are provided with the thermal vias and the heat radiation patterns configured as described in the above embodiment.

  Each light emitting element group 40 includes four light emitting elements 4. Here, in the entire light emitting element group, 16 light emitting elements 4 are arranged in a square shape of 4 rows × 4 columns, and the entire central group A includes 4 rows of 2 rows × 2 columns in the central portion of all the light emitting element groups. The entire peripheral group B is composed of twelve light emitting elements 4 arranged around the entire central group A. With this configuration, the entire light emitting element 4 is reconstructed into all central groups A and all peripheral groups B.

  In each of the mounting substrates 2a, 2b, 2c, and 2d, a central via 7a and a central side heat radiation pattern 8a are formed below the element mounting surface 21 on which the light emitting elements 4 included in the entire central group A are mounted, A peripheral via 7b and a peripheral heat dissipation pattern 8b are formed below the element mounting surface 21 on which the light emitting elements 4 included in the group B are mounted.

  The wirings between the plurality of mounting substrates 2a to 2d are such that the light emitting elements 4 are wired in series in each substrate, and the wiring patterns 3 of the substrates 2a to 2d are serially connected in series between the substrates with bonding wires L1. Connected. The input terminal (here, the mounting board 2a side) and the output terminal (here, the mounting board 2d side) of the group of mounting boards connected in series are bonded to the wiring pattern 51 of the wiring board 5, respectively. 4 is powered. Thereby, all the light emitting element groups are operated as one light emitter. The plurality of mounting boards 2 may be arranged separately on the plurality of wiring boards 5 or may be arranged directly on the heat sink 6.

  In the present embodiment, the central via 7a and the central side heat radiation pattern 8a, the peripheral via 7b and the peripheral side heat radiation pattern 8b are formed corresponding to the whole central group A and the whole peripheral group B of the whole light emitting element group, respectively. Thus, the influence of heat from all the peripheral groups B on all the central groups A can be prevented. As a result, even when a plurality of mounting substrates 2 are densely arranged, the temperature of all the central groups A in the entire light emitting element group can be reduced and the entire temperature can be averaged, and the luminous efficiency and reliability can be achieved. Can be increased.

  In addition, this invention is not limited to the structure of the said various embodiment, A various deformation | transformation is possible suitably in the range which does not change the meaning of invention. For example, in the above-described embodiment, the thermal via 7 and the heat radiation pattern 8 are divided in two or more in the central part and in the peripheral part in a plan view, and the thermal influences in each part are obtained. It may be avoided.

DESCRIPTION OF SYMBOLS 1 Light emitting device 2 Mounting board 21 Element mounting surface 3 Wiring pattern 31 Positive electrode part 32 Negative electrode part 4 Light emitting element 40 Light emitting element group 41 Central group 42 Peripheral group 5 Wiring board 7 Thermal via 7a Central via (central thermal via)
7b Peripheral via (peripheral thermal via)
71 Gap 72, 73 Current-carrying via 8 Heat radiation pattern 8a Center side heat radiation pattern 8b Peripheral side heat radiation pattern A All central groups (central group)
B All peripheral groups (neighboring groups)

Claims (5)

In a light-emitting device including a mounting substrate, a wiring pattern provided on or inside the mounting substrate, and a light-emitting element group including a plurality of light-emitting elements mounted on the wiring pattern,
A thermal via for dissipating heat from the light emitting element, at least part of which is provided in the mounting substrate in a direction perpendicular to the element mounting surface;
A heat dissipating pattern that is provided in the mounting substrate in a direction parallel to the element mounting surface and intersects the thermal via, and
The light emitting element group has a central group located in the central portion of the light emitting element group, and a peripheral group disposed around the central group,
The thermal via has a central thermal via corresponding to the central group and a peripheral thermal via corresponding to the peripheral group,
The heat dissipation pattern has a central heat dissipation pattern connected to the central thermal via and a peripheral heat dissipation pattern connected to the peripheral thermal via,
The light emitting device, wherein the central thermal via and the central heat dissipation pattern and the peripheral thermal via and the peripheral heat dissipation pattern are not in contact with each other.   In the mounting substrate, the center side heat dissipation pattern and the center side thermal via have a gap with the peripheral side heat dissipation pattern and the peripheral side thermal via, and the center side heat dissipation pattern holds the gap while the mounting substrate. The light-emitting device according to claim 1, wherein the light-emitting device is provided so as to extend toward the peripheral side and increase in pattern area as the distance from the element mounting surface increases.   3. The light emitting device according to claim 1, wherein the via located at a position not in contact with the wiring pattern extends toward the surface of the mounting substrate and is exposed on the surface side of the mounting substrate.   At least two of the thermal vias are energized vias that pass through the mounting substrate and energize the light emitting element, and the energized vias are connected to the positive and negative electrodes of the light emitting element, respectively. 4. The light emitting device according to claim 1, wherein the light emitting device is connected to a positive electrode portion and a negative electrode portion of the wiring pattern, respectively.   The center group and the peripheral group in the entire light emitting element group in a configuration in which a plurality of mounting boards on which the light emitting element group is densely mounted are densely mounted on the wiring board. The light-emitting device according to claim 1, further comprising a thermal via and a heat radiation pattern satisfying any one of the items.

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