JP2014011362A - Light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a long light emitting device which efficiently releases heat generated by a semiconductor light emitting element.SOLUTION: In a light emitting device 100, multiple mounting parts 6A corresponding to parts of a metal part 6 and on which multiple LED chips 7 are mounted are provided at multiple recessed parts 10 on a substrate 1. All of or at least parts of the mounting parts 6A are exposed from a resin part 3 on the rear surface side of the substrate 1.

Description

  The present invention relates to a light emitting device, and particularly to a light emitting device including a plurality of semiconductor light emitting elements and a substrate on which the plurality of semiconductor light emitting elements are mounted.

  2. Description of the Related Art In recent years, semiconductor light emitting devices such as light emitting diodes (LEDs) as light sources have been used as backlight sources in liquid crystal display devices such as liquid crystal televisions and illumination light sources in illumination devices as highly efficient and space-saving light sources. As widely used. In a backlight light source, an illumination light source, and the like, the LED is configured as a light emitting device (light emitting module).

  The light emitting device is configured by sealing an LED disposed on a substrate with a resin. For example, in an edge light type backlight unit, a light-emitting device configured by one-dimensionally arranging a plurality of LEDs on a substrate is used.

  By the way, as the light emitting device, there are a surface mount type (SMD) and a COB type (Chip On Borad). The SMD type light emitting device is a package type light emitting device in which an LED chip is mounted in a cavity formed of resin or the like, and the inside of the cavity is sealed with a phosphor-containing resin. On the other hand, a COB type light emitting device is a device in which an LED itself (bare chip) is directly mounted on a substrate, the bare chip and a wiring pattern on the substrate are wire-bonded, and the bare chip is sealed with a phosphor-containing resin. is there. Compared to the SMD type, the COB type light emitting device is superior in cost and light rate, and there is a high demand for the development of a light source employing the COB type light emitting device.

  An example of a COB light-emitting device will be described with reference to FIGS. 4 is a plan view of the COB type light emitting device 1002, and FIG. 5 is a cross-sectional view of the light emitting device 1002 (a cross-sectional view taken along line Y-Y ′ in FIG. 4).

  The light emitting device 1002 includes a plurality of LED chips 1010 and a substrate 1020 on which the LED chips 1010 are mounted. The substrate 1020 includes a long rectangular resin portion 1021 and a metal wiring portion 1022 formed integrally with the resin portion 1021. The resin portion 1021 is provided with a plurality of concave portions 1021a for accommodating the LED chips 1010 along the longitudinal direction thereof. The inner surface of the recess 1021a has a bottom surface 1021b that is a mounting surface on which the LED chip 1010 is mounted, and an inner side surface 1021c that surrounds the LED chip 1010. The resin part 1021 is formed by injection molding. 4 and 5, the resin portion 1021 and the metal wiring portion 1022 are hatched for easy understanding of the structure of the substrate 1020. However, the bottom surface 1021b of the recess 1021a in the resin portion 1021 is not hatched.

  The LED chip 1010 is mounted on the bottom surface 1021b of the recess 1021a and is electrically connected to the adjacent LED chip 1010 and the metal wiring part 1022 by a bonding wire 1011. The metal wiring portion 1022 is a plate-like wiring member that conducts electricity, and is arranged side by side along the longitudinal direction of the resin portion 1021. Among the plurality of metal wiring portions 1022 provided on the substrate 1020, the metal wiring portion 1022 located on the leftmost side in FIGS. 4 and 5 is electrically connected to an electrode terminal (not shown) of the connector portion 1012. ing. A wire harness (not shown) for supplying power to the LED chip 1010 is connected to the connector portion 1012.

  The recess 1021a after the LED chip 1010 is mounted is filled with a sealing resin 1013 for sealing the LED chip 1010 and the bonding wire 1011.

  Note that a light-emitting device in which an LED element made of an LED chip is directly mounted on a substrate is disclosed in Patent Document 1, for example. In this Patent Document 1, the LED chip is mounted on a metal wiring formed on a resin substrate. 4 and FIG. 5, the metal wiring portion 1022 extends to the bottom surface 1021b of the recess 1021a, and the LED chip 1010 is bonded to the extended portion. State.

JP 2012-059376 A (published March 22, 2012)

  However, since the metal wiring part 1022 is entirely covered with the resin part in the structure of the prior art, there is a problem that heat generated from the LED chip is likely to be trapped inside the light emitting device. When heat is trapped inside the light emitting device, the temperature of the LED rises, causing a decrease in luminance and a decrease in light emission efficiency.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a long heating device capable of efficiently releasing heat generated from a semiconductor light emitting element such as an LED.

  In order to solve the above problems, a light-emitting device of the present invention includes a plurality of semiconductor light-emitting elements, a long substrate having a plurality of recesses on which the plurality of semiconductor light-emitting elements are mounted, and the plurality of recesses. A phosphor resin that covers the plurality of semiconductor light emitting elements that are filled and mounted, and the substrate includes a resin portion and a metal portion, and the concave portion is formed along a longitudinal direction. The plurality of recesses are provided with a plurality of mounting portions on which the plurality of semiconductor light emitting elements are mounted, which corresponds to a part of the metal portion, and all or at least a part of the plurality of mounting portions is the substrate. It is characterized by being exposed from the resin part on the back side opposite to the front side where the plurality of semiconductor light emitting elements are mounted.

  According to the above configuration, since the mounting portion on which the semiconductor light emitting element is mounted in the metal portion is exposed from the resin portion on the back side of the substrate, the heat generated from the semiconductor light emitting element is emitted through the mounting portion through the light emitting device. It is easy to escape to the outside, and it is possible to suppress a decrease in luminance and light emission efficiency of the semiconductor light emitting element due to heat generation.

  In the light emitting device of the present invention, the plurality of mounting portions exposed from the resin portion may be configured to have the same height as the resin portion.

  According to the said structure, since a mounting part contacts another member in the state in which the light-emitting device was externally mounted on the other member, heat can be efficiently transmitted to another member and heat dissipation improves.

  In the light emitting device of the present invention, the plurality of mounting portions exposed from the resin portion may further protrude from the resin portion. In this case, it is more preferable that the plurality of mounting portions have the same protruding amount.

  According to the above configuration, since the mounting portion contacts the other member without contacting the resin portion with the light emitting device externally mounted on the other member, both the mounting portion and the resin portion are in contact with the other member. Compared with the case, the heat dissipation of the mounting part is improved. In particular, by aligning the amount of protrusion of each mounting portion, the mounting portion uniformly contacts other members, heat can be more efficiently transmitted to the other members, and heat dissipation is improved.

  In the light emitting device of the present invention, a plurality of conductive members wire-bonded to at least a part of the plurality of semiconductor light emitting elements corresponding to a part of the metal part between the plurality of mounting parts on the substrate. And the plurality of mounting portions and the plurality of conductive portions are formed apart from each other, and the conductive portion is disposed on the surface side of the mounting portion, whereby the mounting portion and the A step may be provided between the conductive portion and a high reflectance resin corresponding to a part of the resin portion.

  According to the above configuration, since the light of the semiconductor light emitting element is reflected by the high reflectance resin provided at the step between the mounting portion and the conductive portion, the light emitted from the semiconductor light emitting element is efficiently externalized. It becomes possible to take out. In addition, since the step is formed between the mounting portion and the conductive portion, the recess in which the semiconductor light emitting element is mounted has a configuration like a two-step bottom, and the semiconductor light emitting element is mounted in the most recessed portion. It becomes. And the volume of this most recessed part is smaller than the volume of the bottom part of the 1st step in the surface side of the board | substrate in a recessed part. For this reason, the phosphor resin filled in the concave portion using a dispenser or the like is concentrated in the most depressed position where the semiconductor light emitting element is mounted by capillary action, and highly efficient light conversion is possible.

  Furthermore, in this case, the inner surface of the concave portion is an inner surface made of a highly reflective resin, a mounting surface that is a mounting surface of the mounting portion and is subjected to high reflectance plating, and the conductive portion adjacent to the mounting portion. It is also possible to have a structure having a connection surface of the bonding wire and a bottom surface made of a surface of the high reflectance resin provided at the step.

  According to this, the entire inner surface of the recess becomes highly reflective, and the light emitted from the semiconductor light emitting element can be extracted to the outside more efficiently.

  In the light emitting device of the present invention, a connector for connecting the light emitting device to another light emitting device may be provided at both ends of the substrate in the longitudinal direction.

  Using the connector for connection, the light emitting devices can be connected to each other, and a longer light emitting device can be easily configured.

  The present invention has an effect that it is possible to realize a long heat generating device capable of efficiently releasing heat generated from a semiconductor light emitting element.

It is sectional drawing of the light-emitting device which concerns on Embodiment 1 of this invention. It is a simple top view of the light-emitting device which concerns on Embodiment 1, 2 of this invention. It is sectional drawing of the light-emitting device which concerns on Embodiment 2 of this invention. It is a top view of the conventional COB type light-emitting device which shows a prior art. It is sectional drawing of the conventional COB type light-emitting device.

[Embodiment 1]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

(Structure of light emitting device)
FIG. 2 is a simplified plan view of the light emitting device according to the embodiment of the present invention. The light-emitting device 100 is a COB-type light-emitting device, and FIG. 1 shows a cross-sectional view of the light-emitting device 100 (cross-sectional view cut along the line XX ′ in FIG. 2).

  As shown in FIG. 2, the light emitting device 100 is a COB connection type LED device that is a long light emitting device, and includes a connector concave connector 4 and a connector convex projection 5 at both ends in the longitudinal direction. ing. Two light emitting devices 100 can be connected in the longitudinal direction by connecting the connecting connector convex portion 5 of another light emitting device 100 to the connecting connector concave portion 4 of the light emitting device 100. Furthermore, by connecting the connecting connector concave portion 4 of another light emitting device 100 to the connecting connector convex portion 5 of the light emitting device 100, the three light emitting devices 100 can be connected in the longitudinal direction. By connecting the two light emitting devices 100 via the connecting connector recess 4 and the connecting connector convex portion 5, the two light emitting devices 100 are also electrically connected to each other.

  As shown in FIG. 1, such a light emitting device 100 is filled with a plurality of LED chips (semiconductor light emitting elements) 7, a substrate 1 having a plurality of recesses 10 on which the LED chips 7 are mounted, and the recesses 10. And a sealing resin 2 made of a phosphor resin, which covers and solidifies the mounted LED chip 7.

  The substrate 1 is an elongated rectangular member, and includes a resin part 3 made of a highly reflective resin and a metal part 6 formed integrally with the resin part 3. The substrate 1 is formed, for example, by injection molding using a mold. Hereinafter, the side on which the LED chip 7 of the substrate 1 is mounted is referred to as the front surface, and the opposite side is referred to as the back surface. A concave portion 10 is formed in the resin portion 3 on the surface side of the substrate 1 along the longitudinal direction.

  The metal part 6 includes a plurality of mounting parts 6A on which the LED chips 7 are mounted and a plurality of conductive parts 6B to which bonding wires 8 connected to the LED chips 7 are connected. The plurality of mounting portions 6 </ b> A and the plurality of conductive portions 6 </ b> B are alternately arranged along the longitudinal direction of the substrate 1.

  Among these, the plurality of mounting portions 6 </ b> A are provided corresponding to the recesses 10, and the plurality of conductive portions 6 </ b> B are provided correspondingly between the recesses 10 and the recesses 10. A plurality of LED chips 7 are COB-mounted on these mounting portions 6A one or more at a time, and two LED chips 7 are mounted in the example of FIG. The mounting surface of the mounting portion 6A is provided with high reflectivity plating 9 using Au or Ag.

  The plurality of LED chips 7 mounted on one mounting portion 6A are connected to the first electrode and the second electrode provided on the upper surface by using bonding wires 8 made of Au wire or the like, and the remaining second electrodes The first electrode is connected to the adjacent conductive part 6B. The plurality of LED chips 7 are connected in series along the longitudinal direction of the substrate 1 by connecting the LED chips 7 or the conductive portions 6 </ b> B with bonding wires 8.

  Among the mounting portion 6 </ b> A and the conductive portion 6 </ b> B constituting the metal portion 6, the plurality of conductive portions 6 </ b> B are covered with the resin portion 3 on the back surface of the substrate 1. On the other hand, the plurality of mounting portions 6 </ b> A are exposed from the resin portion 3 on the back surface of the substrate 1. Since the mounting portion 6A is exposed from the resin portion 3 on the back surface of the substrate 1, heat of the LED chip 7 is easily released from the mounting portion 6A, and it is possible to suppress a decrease in luminance and light emission efficiency of the LED. The effect of exposing the mounting portion 6A on the back surface of the substrate 1 is that the thermal resistance value is improved by about 26% and the light emission efficiency is also approximately compared with the configuration in which the mounting portion 6A is not exposed on the back surface of the substrate 1. It is confirmed that an improvement of 1.3% is expected.

  In the present embodiment, the exposed mounting portion 6A is at the same height as the resin portion 3 on the back surface side of the substrate 1, and the resin portion 3 and the mounting portion 6A are flush with each other on the back surface of the substrate 1. . With such a configuration, when the light emitting device 100 is externally mounted on another member, the other member and the mounting portion 6A come into contact with each other, and the heat transmitted to the mounting portion 6A is another member. The heat generated in the LED can be released more effectively.

  Here, more preferably, the plurality of mounting portions 6 </ b> A are all exposed from the resin portion 3 on the back surface of the substrate 1. However, at least some of the plurality of mounting portions 6A may be exposed. Similarly, more preferably, all of the plurality of mounting portions 6 </ b> A have the same height as the resin portion 3 on the back surface of the substrate 1. However, a configuration in which a part of the plurality of mounting portions 6A is not at the same height as the resin portion 3 and does not come into contact with other externally mounted members may be employed.

  Furthermore, in the present embodiment, both the mounting portion 6A and the conductive portion 6B are made of rectangular metal pieces having the same thickness, and the plurality of mounting portions 6A should be exposed on the back side of the substrate 1. These are disposed below the plurality of conductive portions 6B. In other words, the plurality of conductive portions 6B are arranged on the surface side of the substrate 1 with respect to the mounting portion 6A. Therefore, a step is formed between the mounting portion 6A and the conductive portion 6B.

  At such a step between the mounting portion 6A and the conductive portion 6B, the resin portion 3 is provided so as to connect the mounting surface of the mounting portion 6A and the bonding wire connection surface of the conductive portion 6B. The surface 3b is tapered so as to open to the surface side of the substrate 1. As described above, since the resin portion 3 is a highly reflective resin, the surface 3b of the resin portion 3 that is tapered toward the front surface side of the substrate 1 efficiently reflects the light emitted from the LED chip 7. To do. As a result, the LED light can be efficiently extracted outside.

  In addition, since a step is formed between the mounting portion 6A and the conductive portion 6B, the concave portion 10 on which the LED chip 7 is mounted has a configuration like a two-step bottom, and the LED chip 7 is mounted on the most concave portion. Will be. The volume of the most recessed portion is smaller than the volume of the bottom portion of the first stage on the surface side of the substrate 1 in the recess 10. For this reason, the phosphor resin, which is the sealing resin 2 filled in the recesses using a dispenser or the like, is concentrated in the most depressed position where the LED chip 7 is mounted by capillary action, and highly efficient light conversion is achieved. It becomes possible.

  Moreover, the inner surface of the recessed part 10 in which the LED chip 7 is mounted is the inner surface 3a of the resin part 3 made of high-reflectance resin, and the mounting surface on which the high-reflectance plating 9 is applied, which is the mounting surface of the mounting part 6A. A high-reflecting portion having a connection surface of bonding wires in the conductive portion 6B on both sides of the mounting portion 6A and a bottom surface formed by the surface 3b of the resin portion 3 made of a high-reflectance resin that connects the mounting portion 6A and the connecting surface. It functions as a reflector. By setting it as such a structure, the light of the LED chip mounted in the recessed part 10 is taken out efficiently from the inside of the recessed part 10, and the luminous efficiency of LED can be raised.

  Moreover, according to the said structure, the inner surface 3a of the resin part 3 which consists of high reflectance resin is tapered so that it may open to the surface side of the board | substrate 1 seeing from the LED chip 7 mounted in the recessed part 10. FIG. Yes. Thereby, the light emitted from the LED chip 7 can be reflected more efficiently than the configuration in which the inner surface is parallel to the normal direction of the substrate 1, and the light from the LED can be efficiently extracted to the outside.

[Embodiment 2]
Another embodiment of the present invention will be described. For convenience of explanation, members having the same functions as those described in the first embodiment are given the same member numbers, and description thereof is omitted.

(Structure of light emitting device)
FIG. 2 is a simplified plan view of a light emitting device according to another embodiment of the present invention. The light-emitting device 101 is a COB-type light-emitting device, and FIG. 3 shows a cross-sectional view of the light-emitting device 101 (a cross-sectional view taken along the line XX ′ in FIG. 2).

  As shown in FIG. 3, in the light emitting device 101 of the present embodiment, the exposed mounting portion 6 </ b> A protrudes from the resin portion 3 on the back side of the substrate 1. With this configuration, when the light emitting device 101 is externally mounted on another member, the mounting portion 6A comes into contact with the other member without the resin portion 3 being in contact therewith. Therefore, the heat transmitted to the mounting portion 6A is more easily transmitted to the other member than the resin portion 3 is in contact with the other member, and the heat generated in the LED can be released more effectively.

  Here, more preferably, the plurality of mounting portions 6 </ b> A are all exposed from the resin portion 3 on the back surface of the substrate 1. However, at least some of the plurality of mounting portions 6A may be exposed. Similarly, more preferably, all of the plurality of mounting portions 6A protrude from the resin portion 3 on the back surface of the substrate 1. However, a configuration in which a part of the plurality of mounting portions 6 </ b> A is not in contact with other externally mounted members such as a part at the same height as the resin portion 3 may be used.

  And when it is set as the structure which makes the some mounting part 6A protrude rather than the resin part 3 in this way, it arrange | equalizes the amount of protrusions and all the mounting parts 6A contact the other member mounted externally uniformly. Is most preferred. However, even if part of the mounting portion 6A that does not contact other members is included, it is within the scope of the present invention.

  However, in the configuration in which the mounting portion 6A protrudes from the resin portion 3, a step is generated between the back surface side of the substrate 1 and the resin portion 3, so that the external mounting of the light emitting device 101 is slightly but unstable. there is a possibility. Therefore, it is desirable to form according to the needs of the external mounting side.

  The other structure is the same as that of the light emitting device 100 of the first embodiment, but the mounting position of the LED chip 7 in the recess 10 is further lowered by increasing the level difference between the mounting portion 6A and the conductive portion 6B. Become. Thereby, the concentration of the sealing resin 2 in the most recessed portion where the LED chip 7 is mounted can be expected as compared with the light emitting device 100 of the first embodiment, and the light conversion efficiency can be further improved. .

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

DESCRIPTION OF SYMBOLS 1 Board | substrate 2 Sealing resin 3 Resin part 3a Inner side surface 4 Connection connector recessed part (connector connector)
5 Connecting connector projection (connecting connector)
6 Metal part 6A Mounting part 6B Conductive part 7 LED chip (light emitting element)
8 Bonding wire 9 High reflectivity plating 10 Recess 100 Light emitting device 101 Light emitting device

Claims (7)

A plurality of semiconductor light emitting elements;
An elongated substrate having a plurality of recesses on which the plurality of semiconductor light emitting elements are mounted;
A phosphor resin that fills the plurality of recesses and covers the mounted semiconductor light emitting elements;
The substrate includes a resin portion and a metal portion, and the recess is formed along the longitudinal direction.
The plurality of concave portions in the substrate are provided with a plurality of mounting portions on which the plurality of semiconductor light emitting elements are mounted, corresponding to a part of the metal portions, and all or at least a part of the plurality of mounting portions. However, the light emitting device is exposed from the resin portion on the back surface side opposite to the front surface side on which the plurality of semiconductor light emitting elements are mounted on the substrate.   The light emitting device according to claim 1, wherein the plurality of mounting portions exposed from the resin portion have the same height as the resin portion.   The light-emitting device according to claim 1, wherein the plurality of mounting portions exposed from the resin portion protrude from the resin portion.   The light emitting device according to claim 3, wherein the plurality of mounting portions have the same protruding amount.   In the light emitting device of the present invention, a plurality of conductive members wire-bonded to at least a part of the plurality of semiconductor light emitting elements corresponding to a part of the metal part between the plurality of mounting parts on the substrate. And the plurality of mounting portions and the plurality of conductive portions are formed apart from each other, and the conductive portion is disposed on the surface side of the mounting portion, whereby the mounting portion and the 5. The method according to any one of claims 1 to 4, wherein a step is provided between the conductive portion and a high reflectance resin corresponding to a part of the resin portion is provided at the step. The light-emitting device of description.   The inner surface of the recess is an inner surface made of a highly reflective resin, a mounting surface that is a mounting surface of the mounting portion and subjected to high reflectivity plating, and a bonding wire connection in the conductive portion adjacent to the mounting portion. The light emitting device according to claim 5, further comprising: a surface, and a bottom surface made of a surface of a high reflectance resin provided at the step.   The light emitting device according to any one of claims 1 to 6, wherein a connector for connecting the light emitting device to another light emitting device is provided at both longitudinal ends of the substrate. apparatus.

Images