JP2010056460A - Substrate for light-emitting device, light-emitting device using substrate for light-emitting device, and lighting system using light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance heat dissipation properties of a substrate by providing a hole section in the substrate and filling metal into the hole section, and to solve the problem of large variations in heat dissipation in a plan view of the substrate because the hole sections have been arranged in two directions so that they are paired with a light-emitting element as the center in the prior art. <P>SOLUTION: A light-emitting device includes: the substrate having a main surface, a backside positioned at a side opposite to the main surface, and not less than three hole sections penetrating from the main surface to the backside; a metal member positioned in the hole sections; a substrate for light-emitting devices that is arranged on the main surface of the substrate and has an electrode member connected to the metal member electrically; and a light-emitting element arranged on the electrode member. Not less than three hole sections are positioned on a circumference with the center of the light-emitting element as the center so that the intervals of adjacent holes become nearly constant in a plan view of the substrate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a light emitting device including a light emitting element, a light emitting device substrate used in the light emitting device, and an illumination device. The light emitting device and the lighting device can be suitably used for, for example, a backlight power source for an electronic display and a fluorescent lamp.

  Since a light emitting element used in the light emitting device generates heat with light emission, thermal stress is applied to the light emitting device. Therefore, conventionally, a light emitting device provided with a light emitting element is required to have improved durability. Thus, as described in Patent Document 1, a semiconductor package in which a via is provided in a semiconductor package and a conductive metal film is provided in the via has been proposed.

In Cited Document 1, heat generated in the light emitting element is radiated to the back side of the ceramic substrate through the conductive metal film. Thereby, since the heat dissipation in a ceramic substrate is improved, durability of a semiconductor package can be improved.
JP 2005-191097 A

  As described in Patent Document 1, by providing a hole in the base and filling the hole with metal, the heat dissipation of the base can be enhanced. However, in Patent Document 1, since the holes are arranged in two directions so as to be paired with the light emitting element as a center, there is a problem that the variation in heat dissipation is large when the base is viewed in plan. .

  The present invention has been made in view of the above problems, and provides a highly durable light-emitting device that suppresses the concentration of thermal stress on a part of the substrate by suppressing variations in heat dissipation in the substrate. With the goal.

  The light-emitting device of the present invention includes a base having a main surface, a back surface located on the opposite side of the main surface, and three or more holes penetrating from the main surface to the back surface, and a metal member positioned in the hole And a substrate for a light emitting device provided on the main surface of the base body and provided with an electrode member electrically connected to the metal member, and a light emitting element provided on the electrode member. is doing. When the substrate is viewed in plan, three or more holes are located on the circumference centering on the centroid of the light emitting element.

  According to the light emitting device of the present invention, when the base is viewed in plan, three or more holes are located on the circumference centering on the centroid of the light emitting element. For this reason, since the uniformity of the heat dissipation on the main surface of the base body is improved, the dispersion of the heat dissipation in the base body can be suppressed. Thereby, since the concentration of thermal stress on a part of the substrate is suppressed, the durability of the light emitting device can be improved.

  Hereinafter, a light emitting device and a substrate for a light emitting device of the present invention will be described in detail with reference to the drawings.

  As shown in FIGS. 1-3, the light-emitting device 1 concerning the 1st Embodiment of this invention penetrates from the back surface 3b located in the opposite side of the main surface 3a and the main surface 3a, and the main surface 3a to the back surface 3b. A base 3 having at least two holes 5, a metal member 7 located in the hole 5, and an electrode member 9 disposed on the main surface 3 a of the base 3 and electrically connected to the metal member 7. And a light emitting device 13 disposed on the electrode member 9. And when the base | substrate 3 is planarly viewed, the three or more hole parts are located on the circumference X centering on the centroid of the light emitting element 13. FIG.

  As described above, the light-emitting device 1 (light-emitting device substrate 11) of the present embodiment has three or more holes on the circumference X centered on the centroid of the light-emitting element 13 when the base 3 is viewed in plan. 5 is located. In other words, the holes 5 are not concentrated in the two directions that form a pair around the light emitting element 13. Therefore, the heat generated from the light emitting element 13 can be dispersed in a wide range by the hole 5. In the light emitting device 1 (light emitting device substrate 11) of the present embodiment, since these three or more holes 5 are located at substantially constant intervals, heat dissipation on the main surface 3a of the base 3 is performed. The uniformity is improved. Thereby, since the concentration of thermal stress on a part of the substrate 3 is suppressed, the durability of the light emitting device substrate 11 and the light emitting device 1 can be improved.

  In the present embodiment, when the base 3 is viewed in plan, three or more holes 5 are located on the circumference X centered on the centroid of the light emitting element 13. This means that there are three or more hole portions 5 at least partially located on the circumference X centered on the center. That is, it does not mean that the center of the hole 5 is strictly positioned on the circumference X centering on the centroid of the light emitting element 13. The centroid of the light emitting element 13 means the center when the light emitting element 13 is viewed in plan. Specifically, when the shape of the light emitting element 13 is circular when viewed in plan, the center is the center. In addition, when the shape of the light emitting element 13 is rectangular when viewed in plan, the intersection of the diagonal lines is set as the center.

  Furthermore, in the above case, the three or more hole portions 5 are positioned at a substantially constant interval does not mean that the interval between adjacent hole portions 5 is strictly constant, but the width of the hole portions 5. It includes a degree of error.

  As the substrate 3, for example, alumina ceramic, aluminum nitride sintered body, mullite sintered body, ceramic such as glass ceramic, or resin such as epoxy resin can be used. Moreover, the laminated body which piled up resin on ceramics may be sufficient. The durability of the light emitting device 1 can be improved by using a laminate in which a resin is laminated on ceramics. When the light emitting element 13 is energized, the light emitting element 13 emits light and generates heat at the same time. Further, the resin is more easily elastically deformed than ceramics. For this reason, the thermal stress generated by the heat generation of the light emitting element 13 can be absorbed by the resin while the strength of the substrate 3 is improved by the ceramic.

  As the light-emitting element 13, an element that can generate light with driving power may be used. For example, a light emitting diode made of a semiconductor material can be used. Specifically, a light emitting diode mainly composed of GaAs, GaN, or AlN can be used. The light emitting element 13 is connected to an external power source via a metal member 7 disposed in a hole 5 penetrating from the main surface 3a to the back surface 3b of the base 3 and an electrode member 9 disposed on the main surface 3a of the base 3. When energized from (not shown), light can be emitted.

  The electrode member 9 is disposed on the main surface 3 a of the base 3 in the light emitting element 13. Here, as shown in FIGS. 1 to 3, by providing two electrode members 9 that are separated from each other and electrically connected to the light emitting element 13, they can be used as an anode side electrode and a cathode side electrode. As the electrode member 9, it is preferable to use a member having good electrical conductivity and thermal conductivity, and specifically, a metal such as Ag, Cu, Ni, or Au can be used. In particular, it is preferable to use Ni plating or Cu plating because the bondability between the electrode member 9 and the substrate 3 can be improved.

  As the metal member 7, like the electrode member 9, it is preferable to use a member having good electrical conductivity and thermal conductivity. Specifically, a metal such as Ag, Cu, Ni, Au, etc. can be used. . At this time, it is preferable that the component of the metal member 7 and the component of the electrode member 9 are substantially the same. This is because by using the same member as the electrode member 9 as the metal member 7, the bondability between the metal member 7 and the electrode member 9 can be improved. Further, if the metal member 7 and the electrode member 9 are different components, heat tends to accumulate at the interface between the metal member 7 and the electrode member 9 due to a difference in thermal conductivity or a difference in electrical resistance value. By using the same member as the electrode member 9, heat can be smoothly released from the main surface 3a side of the base 3 to the back surface 3b side of the base 3.

  In addition, the light emitting device 1 of this embodiment includes a light transmissive member 15 disposed on the light emitting device substrate 11 and the light emitting element 13. Since the light emitting element 13 is covered with the translucent member 15 as in the present embodiment, the light emitting element 13 can be prevented from being deteriorated by contact with the outside air, and thus the light emitting element 13 can also improve the durability. it can. As the translucent member 15, it is preferable to use a member having high light transmissivity, and for example, a transparent resin such as an epoxy resin or a silicone resin can be used.

  Further, the metal member 7 may be filled in the entire hole portion 5 as shown in FIG. 3, but as shown in FIG. 4, the metal member 7 is directed from the main surface 3a side of the substrate 3 toward the back surface 3b side of the substrate 3. It is preferable to have a through hole penetrating through. In other words, the metal member 7 is preferably formed on the surface of the hole 5. The heat generated in the light emitting element 13 can be efficiently radiated from the main surface 3 a side to the back surface 3 b side of the base 3 through the metal member 7. That is, most of the heat generated in the light emitting element 13 flows into the metal member 7. Therefore, the metal member 7 is likely to thermally expand as compared with the base 3. However, since the metal member 7 has the above-described through holes, the stress applied to the base 3 due to the thermal expansion of the metal member 7 can be relieved, so that the durability of the substrate for the light emitting element 13 can be improved.

  Next, a second embodiment of the present invention will be described.

  As shown in FIG. 5, the light emitting device 1 (light emitting device substrate 11) of the present embodiment has a hole 5 having a larger opening on the back surface 3 b side of the base 3 than on the main surface 3 a side of the base 3. It is characterized by having. As already shown, the light emitting element 13 emits light and generates heat when energized. Due to this heat generation, the base 3 is thermally expanded. At this time, since the base 3 on the main surface 3a side where the light emitting element 13 is disposed is more thermally expanded than the back surface 3b, the base 3 is warped toward the back surface 3b. Therefore, greater thermal stress is applied to the base 3 on the back surface 3b side than on the main surface 3a side.

  The light-emitting device 1 (light-emitting device substrate 11) of the present embodiment has a hole portion 5 having a diameter R2 that is larger in the opening portion on the back surface 3b side of the base body 3 than in the opening portion on the main surface 3a side of the base body 3. is doing. Therefore, the effect of relaxing the stress applied to the back surface 3 b side of the base 3 is greater than the effect of relaxing the stress applied to the main surface 3 a side of the base 3. As a result, compared to the first embodiment, the thermal stress applied to the base 3 can be efficiently relaxed, so that the durability of the base 3 can be enhanced.

  As shown in FIGS. 6 and 7, the metal member 7 preferably has a recess 17 that opens to the back surface 3 b side of the base 3. By having the concave portion 17 opened on the back surface 3b side of the base body 3 to which a relatively large thermal stress is applied, the above-described thermal stress can be absorbed by the concave portion 17, and therefore on the back surface 3b side of the base body 3. This is because the applied thermal stress can be further relaxed.

  At this time, as shown in FIG. 7, the shape of the concave portion 17 is preferably an edge shape composed of two inclined side surfaces when viewed in cross section. When the concave portion 17 has a bottom surface, the thermal stress is likely to be concentrated on a portion of the base 3 that is located at the same height as the bottom surface. However, the concave portion 17 has an edge shape and has a concave portion. This is because, by not having the 17 bottom surface, it is possible to avoid the concentration of thermal stress on the portion of the base body 3 located at the same height as the bottom surface. In order to obtain the effect of stress relaxation by the concave portion 17 more reliably, as shown in FIG. 7, the opening portion of the concave portion 17 is larger than the diameter R1 of the opening portion of the hole portion 5 on the main surface 3a side of the base 3. The diameter R3 is preferably large.

  Next, a third embodiment of the present invention will be described.

  As shown in FIG. 8, the light-emitting device 1 (light-emitting device substrate 11) of the present embodiment has a first circumference X <b> 1 centered at the center of the light-emitting element 13 when the base 3 is viewed in plan view and Three or more hole portions 5 are positioned on the second circumference X2 located outside the first circumference so that the interval between the adjacent hole portions 5 is substantially constant. It is a feature.

  The uniformity of heat dissipation in the circumferential direction of this circumference is improved by forming three or more hole parts 5 so that the interval between adjacent hole parts 5 is substantially constant on one circumference. Can do. In the present embodiment, the interval between the adjacent hole portions 5 is substantially constant on the first circumference X1 and on the second circumference X2 located outside the first circumference X1. Three or more holes 5 are located respectively. Thereby, since the dispersion | variation in heat dissipation can be suppressed not only to the circumferential direction of said circumference but to radial direction, compared with 1st Embodiment, on the main surface 3a of the base | substrate 3 The uniformity of heat dissipation can be further improved. As a result, since the concentration of thermal stress on a part of the base 3 is further suppressed, the durability of the light emitting device substrate 11 and further the light emitting device 1 can be further improved.

  Further, as shown in FIG. 8, when the base 3 is viewed in plan, the hole 5 formed on the first circumference X1 and the hole 5 formed on the second circumference X2 are: It is preferable that they are formed to be staggered. This is because the effect of suppressing the concentration of thermal stress on a part of the substrate 3 can be further enhanced.

  Further, as in the present embodiment, when the holes 5 are formed on the first circumference X1 and on the second circumference X2 located outside the first circumference X1, respectively. The diameter R3 of the opening of the recess 17 located on the second circumference X2 is preferably larger than the diameter R3 of the opening of the recess 17 located on the first circumference X1.

  Next, a fourth embodiment of the present invention will be described.

  As shown in FIG. 9, the light emitting device 1 of the present embodiment includes a reflecting member 19 that is disposed on the main surface 3 a of the translucent substrate 3 and has a reflecting surface that reflects light emitted from the light emitting element 13. I have. By providing the reflection member 19 as described above, the light emitted from the light emitting element 13 can be condensed and emitted in a desired light emitting direction.

  More specifically, as shown in FIG. 9, it is located on the main surface 3 a of the translucent substrate 3 so as to surround the light emitting element 13, and the inner peripheral surface reflects light emitted from the light emitting element 13. A frame-like reflecting member 19 that is a reflecting surface to be used can be used.

  The reflecting member 19 may be any member that has a high light reflectance on the surface facing the light emitting element 13. For example, a metal such as an Al, Fe—Ni—Co alloy can be used. Further, a material in which a metal thin film having a high reflectance such as Al, Ag, Au, Pt, Ti, Cr, Cu is disposed on the surface of ceramics such as alumina ceramics and epoxy resin is used as the reflecting member 19. You can also. Furthermore, when using a member that easily corrodes, such as Ag or Cu, as the metal thin film, it is preferable to coat the surface of the metal thin film with a member that does not corrode easily such as Ni.

  Next, the illuminating device concerning one Embodiment of this invention is demonstrated.

  As shown in FIG. 10, the lighting device 21 of the present embodiment includes a light emitting device 1 typified by the above embodiment, a mounting plate 23 on which the light emitting device 1 is mounted, and an electrical wiring 25 that energizes the light emitting device 1. And a light reflecting means 27 for reflecting the light emitted from the light emitting device 1.

  The light emitting device 1 in the illumination device 21 of the present embodiment is placed on the mounting plate 23. At this time, as shown in FIG. 10, since the illumination device 21 of the present embodiment is formed so as to illuminate the lower part, the light emitting device 1 has the light emitting element 13 positioned below the translucent substrate 3. In this way, it is placed on the mounting plate 23. In the illumination device 21 of the present embodiment, the light emitting element 13 emits light by energizing the light emitting device 1 through the electrical wiring 25. And it functions as the illuminating device 21 which illuminates a desired direction by reflecting the emitted light by the light reflecting means 27.

  The lighting device 21 may include only one light emitting device, or may include a plurality of light emitting devices as shown in FIG. Further, when a plurality of light emitting devices 1 are provided, the light emitting devices 1 may be arranged in series or in parallel with the electric wiring 25.

  Note that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

It is a perspective view which shows the light-emitting device concerning the 1st Embodiment of this invention. It is a top view of the board | substrate for light-emitting devices in embodiment shown in FIG. It is sectional drawing of embodiment shown in FIG. It is sectional drawing which shows the modification of the light-emitting device concerning the 1st Embodiment of this invention. It is sectional drawing which shows the light-emitting device concerning the 2nd Embodiment of this invention. It is sectional drawing which shows the modification of the light-emitting device concerning the 2nd Embodiment of this invention. It is the expanded sectional view which expanded the area | region A in FIG. It is a top view which shows the board | substrate for light-emitting devices in the light-emitting device concerning the 3rd Embodiment of this invention. It is sectional drawing which shows the light-emitting device concerning the 4th Embodiment of this invention. It is a perspective sectional view showing an illuminating device concerning one embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device 3 ... Base | substrate 3a ... Main surface 3b ... Back surface 5 ... Hole 7 ... Metal member 9 ... Electrode member 11 ... Light-emitting device substrate 13 .. Light emitting element 15... Translucent member 17... Recess 19. Reflecting member 21... Illuminating device 23.

Claims (6)

A base having a main surface and a back surface located on the opposite side of the main surface, and three or more holes penetrating from the main surface to the back surface, a metal member located in the hole, and a main surface of the base A substrate for a light emitting device comprising an electrode member disposed on and electrically connected to the metal member;
A light emitting device provided with a light emitting element disposed on the electrode member,
When the base is viewed in plan, three or more holes are located on a circumference centered on the centroid of the light emitting element.   The light emitting device according to claim 1, wherein the hole has a larger opening on the back surface side of the substrate than an opening on the main surface side of the substrate.   The light emitting device according to claim 2, wherein the metal member has a recess opening on a back surface side of the base.   The light emitting device according to claim 2, wherein the metal member has a through hole penetrating from a main surface side of the base toward a back side of the base. A base having a main surface and a back surface located on the opposite side of the main surface, and three or more holes penetrating from the main surface to the back surface, a metal member located in the hole, and a main surface of the base A substrate for a light emitting device comprising an electrode member disposed on and electrically connected to the metal member,
A substrate for a light-emitting device, wherein three or more holes are located on a circumference centered on a centroid of the light-emitting element when the base is viewed in plan. 5. The light emitting device according to claim 1, a mounting plate on which the light emitting device is mounted, an electrical wiring for energizing the light emitting device, and a light reflecting unit that reflects light emitted from the light emitting device. And a lighting device.