JP4862808B2 - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve lifetime and efficiency of a light-emitting device by enhancing the heat dissipation of a light-emitting element, the light-emitting device using an LED. <P>SOLUTION: The light-emitting device is formed by mounting one or more light-emitting element sub-mount structures 3, which is equipped with a mounting substrate 30 having wiring parts 301 and 302 and an LED chip 33 mounted on the mounting substrate 30, on a first heat dissipating substrate which also serves as a wiring substrate. The mounting substrate 30 in the light-emitting element sub-mount structure 3 consists of two conductor blocks 301 and 302 which sandwich an insulating member 300. A p-side electrode and an n-side electrode of the LED chip 33 are connected to the conductor blocks 301 and 302, respectively. A surface, which is in the side different from the side which faces the first heat dissipating substrate of the light-emitting element sub-mount structure 3, is contacted or joined to a second heat dissipating substrate. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a light emitting device using an LED (light emitting diode).

In recent years, LED chips that emit blue light or ultraviolet light have been developed using gallium nitride-based compound semiconductors. An attempt has been made to develop an LED light emitting device that can emit light having a color different from that of the LED chip, including white, by combining the LED chip with various phosphors. This LED light emitting device has advantages such as small size, light weight, and power saving, and is currently widely used as a light source for display, an alternative light source for a small light bulb, or a light source for a liquid crystal panel. However, since current LEDs have low brightness per chip, when used for illumination light sources, liquid crystal panel light sources, etc., LEDs are formed by mounting and sealing LED chips on a mounting substrate having a wiring portion. Generally, a plurality of packages are mounted on a printed wiring board to obtain a necessary brightness. In order to obtain a large light output, it is necessary to increase the injection current. Patent Document 1 discloses a structure in which a metal block in which an LED chip is housed in a recess is attached on a metal flat plate.
JP 2002-141558 A

  Since the current LED has an efficiency of about 10%, it has a characteristic that most of the input electric energy becomes heat, and the calorific value increases when a large amount of current flows. It is known that when the temperature of the LED rises due to heat generation, characteristics such as life and efficiency are adversely affected. However, since the printed wiring board as described above is generally formed using a resin material such as polyimide or epoxy having low thermal conductivity, there is a problem that heat generated in the LED package cannot be efficiently dissipated. It was.

  Therefore, the present applicant previously filed a patent application for a structure plan for solving this problem in Japanese Patent Application No. 2003-148050. A light emitting element submount structure composed of a mounting substrate having a wiring portion and an LED chip mounted on the mounting substrate is mounted on a wiring substrate composed of a wiring pattern formed on a metal plate via an insulating layer to emit light. Made with equipment. In this light emitting device, the wiring portion on the mounting board is drawn out in the direction of the wiring board and electrically connected to the wiring pattern, and a part of the metal plate is exposed and is in contact with the mounting board. Since the heat radiation performance is improved by bringing the exposed portion of the metal plate into contact with the mounting substrate, the heat generated in the LED chip can be quickly released to the wiring substrate side. Furthermore, since the mounting substrate and the wiring substrate are joined and the heat radiation path can be formed by a single reflow process, the manufacturing process can be simplified as compared with the conventional example.

  However, in the above-described light emitting device, there is no heat dissipation path other than the contact portion with the wiring substrate on the back surface side of the light emitting element submount structure. Therefore, if the current injected into the LED chip is increased beyond a certain limit in order to obtain the light output required for illumination, the temperature of the LED chip rises due to heat generation, which adversely affects the characteristics such as the lifetime and efficiency of the light emitting device. There was a problem of giving.

  In order to solve the above problems, the invention of claim 1 is a mounting substrate 30 having wiring portions 301 and 302 and an LED chip 33 mounted on the mounting substrate 30 as shown in FIGS. A light-emitting device in which one or a plurality of light-emitting element submount structures 3 each having a plurality of light-emitting element submount structures 3 are mounted on a first heat dissipation substrate 1 that also serves as a wiring board. The mounting substrate 30 includes two conductor blocks 301 and 302 with an insulating member 300 interposed therebetween. The p-side electrode and the n-side electrode of the LED chip 33 are connected to the two conductor blocks 301 and 302, respectively. The surface of the light emitting element submount structure 3 that is different from the side facing the first heat dissipation substrate 1 is in contact with or joined to the second heat dissipation substrate 2. is there.

In order to solve the above problems, the invention of claim 2 is a mounting substrate 30 having wiring portions 301 and 302 and an LED chip 33 mounted on the mounting substrate 30 as shown in FIGS. a first light-emitting element submount structure 3, a plurality mounted comprising the light emitting device to the first heat radiating substrate 1 serving also as a wiring substrate with bets, the first light emitting element submount structure 3 A second surface having the same structure as that of the first light emitting element submount structure 3 is formed by contacting or joining a surface on the side different from the side facing the first heat radiating substrate 1 to the second heat radiating substrate 2. A plurality of light emitting element submount structures 3 are mounted on a third heat dissipation substrate 4 that also serves as a wiring board, and the side facing the third heat dissipation substrate 4 of the second light emitting element submount structure 3 is provided. Is different from the first side of the second heat dissipation substrate 2. Contact or bonded to the surface of a different side to the side where the light emitting device submount structure 3 in contact with or joined, the first, the first light emitting element submount sandwiched second radiating substrate 1 the structure 3, the second, and the second light-emitting element submount structure 3 which is sandwiched the third radiating substrate 2 and 4, are staggered in a zigzag lattice shape, the second The second light emitting element submount structure 3 is not disposed on the heat radiation substrate 2 in contact with the first light emitting element submount structure 3 or directly behind the bonding surface .

  According to the first aspect of the present invention, since the heat dissipation path from the light emitting element submount structure is increased, the heat dissipation of the light emitting element submount structure is improved, and the temperature of the LED chip is reduced. In addition, since the light-emitting element submount structure is composed of a conductive block having excellent thermal conductivity, heat transferred from the LED chip to the mounting substrate is quickly diffused toward the first and second heat dissipation substrates. To do. Thereby, the heat dissipation of the light emitting element submount structure is improved, and the temperature of the LED chip is further reduced.

  According to the invention of claim 2, since the heat radiation path from the light emitting element submount structure is increased, the heat radiation property of the light emitting element submount structure is improved and the temperature of the LED chip is lowered. In addition, the distance between adjacent light emitting element submount structures can be maximized. Therefore, the temperature of the light emitting element submount can be lowered, and the temperature of the LED chip is further lowered.

Example 1
1 and 2 show a schematic structure of the first embodiment. As the light-emitting element submount structure 3, as shown in FIG. 1, a mounting substrate 30 is composed of two conductor blocks 301 and 302 with an insulating member 300 interposed therebetween, and the p-side electrode and the n-side electrode of the LED chip 33 are The one connected to each of the two conductor blocks 301 and 302 is used.

  As shown in FIG. 2, the first and second heat dissipation substrates 1 and 2 are arranged in parallel, and the light emitting element submount structure 3 is arranged between the two heat dissipation substrates 1 and 2. The light emitting element submount structure 3 and the heat dissipating substrates 1 and 2 are contacted or joined. Further, the second and third heat radiation substrates 2 and 4 are arranged in parallel, and the light emitting element submount structure 3 is arranged between the two heat radiation substrates 2 and 4. The light-emitting element submount structure 3 and the heat dissipation substrates 2 and 4 are contacted or joined.

  The light emitting element submount structures 3 are arranged in a staggered pattern as shown in FIG. That is, in the heat dissipation substrate 2 that connects the light emitting element submount structure 3 on both sides, the light emitting element submount structure 3 on the other surface is disposed on the back side of the contact surface with the light emitting element submount structure 3 on one side. Do not place. The number of the heat dissipating substrates, the material, and the arrangement interval of the light emitting element submounts are not limited to those illustrated.

  According to the present embodiment, the heat generated by the light emitting element submount structure can be efficiently transferred to the two heat dissipation substrates. Further, high-density mounting is possible because the heat dissipation substrate also serves as electrical connection. Compared to the conventional example, the injection current can be increased while suppressing the temperature rise of the LED chip, and the light output can be increased. In addition, heat dissipation is improved by arranging the light emitting element submount structures in a staggered pattern.

(Example 2)
FIG. 3 shows a schematic structure of the second embodiment. The light emitting element submount structure 3 and the heat dissipation substrates 1 and 2 are alternately arranged. The p-pole side of the light-emitting element submount structure 3 is connected to one end of the heat dissipation substrates 1 and 2 and the n-pole side is connected to the other end. An assembly including the light emitting element submount structure 3 and the heat dissipation substrates 1 and 2 that are electrically connected in series is formed. The number of the heat dissipation substrates, the material, and the arrangement interval of the light emitting element submount structures are not limited.

  According to the present embodiment, the heat generated by the light emitting element submount structure can be efficiently transferred to the two heat dissipation substrates. Further, high-density mounting is possible because the heat dissipation substrate also serves as electrical connection. Compared to the conventional example, the injection current can be increased while suppressing the temperature rise of the LED chip, and the light output can be increased. In addition, since a uniform current flows through the LEDs constituting the assembly, there is little variation in light output between individual LED chips.

(Example 3)
FIG. 4 shows a schematic structure of the third embodiment. The heat dissipating substrates 1 and 2 are configured by fixing the lead frames 5 arranged at regular intervals with the resin material 6. The light-emitting element submount structure 3 and the heat-dissipating substrate 1 are electrically connected in series by connecting the light-emitting element submount structure 3 to the lead frame 5 with the lead frame surfaces of the heat-dissipating substrates 1 and 2 facing each other. 2 constitutes an aggregate. The number of heat dissipation substrates, the material, the arrangement interval of the light emitting element submount structures, the material and thickness of the lead frame, and the material of the resin material are not limited.

  According to the present embodiment, the heat generated by the light emitting element submount structure can be efficiently transferred to the two heat dissipation substrates. Further, high-density mounting is possible because the heat dissipation substrate also serves as electrical connection. Compared to the conventional example, the injection current can be increased while suppressing the temperature rise of the LED chip, and the light output can be increased. Since a uniform current flows through the LEDs constituting the assembly, there is little variation in light output between individual LED chips.

Example 4
FIG. 5 shows a schematic structure of the fourth embodiment. The heat dissipating substrates 1 and 2 are configured by fixing the lead frames 5 arranged at regular intervals with the resin material 6. The light emitting element submount structure 3 is joined to the lead frame 5 with the lead frame surfaces of the heat dissipation substrates 1 and 2 facing each other. An assembly including the light emitting element submount structure 3 and the heat dissipation substrates 1 and 2 that are electrically connected in series is formed. Further, metal plates 11 and 21 are joined to the opposite surfaces of the heat dissipation substrates 1 and 2 to the lead frame 5. In this way, at least one of the first and second heat dissipation substrates is a substrate using a metal lead frame on the side facing the submount structure, so that the light emitting element sub-layer is interposed via the lead frame. Heat dissipation from the mount structure is improved. In addition, since the lead frame has good workability, the degree of freedom of wiring to each light emitting element submount structure increases. The number of heat-dissipating substrates, the material, the arrangement interval of the light emitting element submounts, the material and thickness of the lead frame, the material of the resin material, the material and the shape of the metal plate are not limited.

  According to the present embodiment, the heat generated by the light emitting element submount structure can be efficiently transferred to the two heat dissipation substrates. Further, high-density mounting is possible because the heat dissipation substrate also serves as electrical connection. Compared to the conventional example, the injection current can be increased while suppressing the temperature rise of the LED chip, and the light output can be increased. Since a uniform current flows through the LEDs constituting the assembly, there is little variation in light output between individual LED chips. By joining the metal plate to the outer surface, the heat dissipation can be further improved.

(Example 5)
FIG. 6 shows a schematic structure of the fifth embodiment. A heat radiating substrate 1 formed by forming a wiring pattern 13 on an insulating layer 12 on a metal plate 11 is provided. Further, a heat dissipation substrate 2 formed by forming a wiring pattern 23 on an insulating layer 22 on a metal plate 21 is provided. The wiring patterns 13 and 23 are opposed to each other and arranged in parallel, and the light emitting element submount structure 3 is arranged between the substrates 1 and 2. The wiring patterns 13 and 23 and the light emitting element submount structure 3 are in contact with or bonded to each other. An assembly including the light emitting element submount structure 3 and the heat dissipation substrates 1 and 2 that are electrically connected in series is formed. The number of the heat dissipating substrates 1 and 2, the material, and the arrangement interval of the light emitting element submount structures are not limited.

  According to the present embodiment, the heat generated by the light emitting element submount structure can be efficiently transferred to the two heat dissipation substrates. Further, high-density mounting is possible because the heat dissipation substrate also serves as electrical connection. Compared to the conventional example, the injection current can be increased while suppressing the temperature rise of the LED chip, and the light output can be increased. In addition, since a uniform current flows through the LED chips constituting the assembly, there is little variation in light output between the individual LED chips. Furthermore, since the insulating member of the heat dissipation substrate can be made thin, the heat dissipation effect to the metal plate is improved. In addition, it is possible to arrange electronic components other than the light emitting elements by using an arbitrary pattern configuration.

(Example 6)
FIG. 7 shows a schematic structure of the sixth embodiment. The heat dissipating substrates 1 and 2 configured around the resin material 6 are arranged in parallel. A lead frame 5 for connecting the opposing heat dissipating substrates 1 and 2 is configured. An assembly including the light emitting element submount structure 3 and the heat dissipation substrates 1 and 2 that are electrically connected in series is formed. The number of heat dissipation substrates, the material, the arrangement interval of the light emitting element submount structures, the material and thickness of the lead frame, and the material of the resin material are not limited.

  According to the present embodiment, the heat generated by the light emitting element submount structure can be efficiently transferred to the two heat dissipation substrates. Further, high-density mounting is possible because the heat dissipation substrate also serves as electrical connection. Compared to the conventional example, the injection current can be increased while suppressing the temperature rise of the LED chip, and the light output can be increased. In addition, since a uniform current flows through the LEDs constituting the assembly, there is little variation in light output between individual LED chips. Furthermore, since the polarity of the light emitting element submount structure connected to the heat dissipation substrate is unified to the p-pole or the n-pole, the mountability is improved.

(Example 7)
FIG. 8 shows a schematic structure of the seventh embodiment. Metal heat dissipating substrates 1 and 2 are provided concentrically. The light emitting element submount structure 3 is disposed between the two heat dissipating substrates 1 and 2. The light emitting element submount structure 3 and the heat dissipating substrates 1 and 2 are in contact with or bonded to each other. The number of the heat dissipation substrates, the material, and the arrangement interval of the light emitting element submount structures are not limited.

  According to the present embodiment, the heat generated by the light emitting element submount structure can be efficiently transferred to the two heat dissipation substrates. Further, high-density mounting is possible because the heat dissipation substrate also serves as electrical connection. Compared to the conventional example, the injection current can be increased while suppressing the temperature rise of the LED chip, and the light output can be increased. Moreover, the light output suitable for a circular instrument apparatus is attained.

(Example 8)
FIG. 9 shows a schematic structure of the eighth embodiment. Polygonal metal heat dissipating substrates 1 and 2 are provided concentrically. The light emitting element submount structure 3 is disposed between the two heat dissipating substrates 1 and 2. The light emitting element submount structure 3 and the heat dissipating substrates 1 and 2 are contacted or joined. The number of heat dissipation substrates, the material, the arrangement interval of the light emitting element submount structures, and the number of polygonal corners (hexagons, octagons, etc.) are not limited.

  According to the present embodiment, the heat generated by the light emitting element submount structure can be efficiently transferred to the two heat dissipation substrates. Further, high-density mounting is possible because the heat dissipation substrate also serves as electrical connection. Compared to the conventional example, the injection current can be increased while suppressing the temperature rise of the LED chip, and the light output can be increased. Further, in a circular shape having a relatively small radius, the bonding property between the light emitting element submount structure and the heat dissipation substrate can be improved.

Example 9
FIG. 10 shows a schematic structure of the ninth embodiment. Circular heat dissipation substrates 1 and 2 are arranged in parallel. The light emitting element submount structure 3 is disposed between the two heat dissipating substrates 1 and 2. The light emitting element submount structure 3 and the heat dissipating substrates 1 and 2 are contacted or joined. Each of the polarities in contact with the bottom of the light emitting element submount structure 3 was connected to the heat dissipation substrates 1 and 2. In addition, as shown to the same figure (b), you may provide metal ring-shaped members 7. FIG. The number of the heat dissipation substrates, the material, and the arrangement interval of the light emitting element submount structures are not limited.

  According to the present embodiment, the heat generated by the light emitting element submount structure can be efficiently transferred to the two heat dissipation substrates. Further, high-density mounting is possible because the heat dissipation substrate also serves as electrical connection. Compared to the conventional example, the injection current can be increased while suppressing the temperature rise of the LED chip, and the light output can be increased. Further, light emission in all directions can be performed using a highly directional LED. Furthermore, when a metal ring-shaped member is used, it is possible to further improve heat dissipation.

(Example 10)
FIG. 11 shows a schematic structure of the tenth embodiment. At least two heat dissipating substrates 1 and 2 made of a flexible conductive material are provided. The p-pole side of the plurality of light-emitting element submount structures 3 is connected to one heat dissipation substrate 1, and the n-pole side is connected to another heat dissipation substrate 2. The light emitting element submount structure 3 and the heat dissipating substrates 1 and 2 are contacted or joined. The number of heat dissipation substrates, the material, and the arrangement interval of the light emitting element submounts are not limited.

  According to the present embodiment, the heat generated by the light emitting element submount structure can be efficiently transferred to the two heat dissipation substrates. Further, high-density mounting is possible because the heat dissipation substrate also serves as electrical connection. Compared to the conventional example, the injection current can be increased while suppressing the temperature rise of the LED chip, and the light output can be increased. Furthermore, since the structure has flexibility, it is possible to realize a light emitter having a shape according to the needs of the user.

  The light emitting device of the present invention can be used as a light source of a display device or a lighting device.

It is sectional drawing of the light emitting element submount structure used for the light-emitting device of Example 1 of this invention. It is sectional drawing of the light-emitting device of Example 1 of this invention. It is sectional drawing of the light-emitting device of Example 2 of this invention. It is sectional drawing of the light-emitting device of Example 3 of this invention. It is sectional drawing of the light-emitting device of Example 4 of this invention. It is sectional drawing of the light-emitting device of Example 5 of this invention. It is sectional drawing of the light-emitting device of Example 6 of this invention. It is sectional drawing of the light-emitting device of Example 7 of this invention. It is sectional drawing of the light-emitting device of Example 8 of this invention. It is a figure which shows the light-emitting device of Example 9 of this invention, (a) is a front view, (b) is sectional drawing. It is a figure which shows the manufacturing process of the light-emitting device of Example 10 of this invention, (a) is sectional drawing of a semi-finished product, (b) is sectional drawing of a finished product.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st heat dissipation board 2 2nd heat dissipation board 3 Light emitting element submount structure 4 3rd heat dissipation board 30 Mounting substrate 33 LED chip 300 Insulating member 301 Conductor block (wiring part)
302 Conductor block (wiring section)

Claims (2)

One or a plurality of light emitting element submount structures each including a mounting substrate having a wiring portion and an LED chip mounted on the mounting substrate are mounted on a first heat dissipation substrate that also serves as the wiring substrate. In the light-emitting device, the mounting substrate in the light-emitting element submount structure includes two conductor blocks sandwiching an insulating member therebetween, and the p-side electrode and the n-side electrode of the LED chip are the two conductors. Connected to each of the blocks, and a surface of the light emitting element submount structure that is different from the side facing the first heat dissipation substrate is in contact with or bonded to the second heat dissipation substrate. Light-emitting device. Light emission in which a plurality of first light emitting element submount structures each including a mounting substrate having a wiring portion and an LED chip mounted on the mounting substrate are mounted on a first heat dissipation substrate that also serves as a wiring substrate. An apparatus, wherein a surface of the first light emitting element submount structure that is different from the side facing the first heat dissipation substrate is in contact with or joined to the second heat dissipation substrate,
A plurality of second light emitting element submount structures having the same structure as the first light emitting element submount structure are mounted on a third heat dissipation substrate also serving as a wiring board, and the second light emitting element submount structure is provided. The surface on the side different from the side facing the third heat dissipation substrate is a surface on a side different from the side on which the first light emitting element submount structure contacts or is joined on the second heat dissipation substrate. Contact or join,
The first, a first light emitting element submount structure that is sandwiched second radiating board, and the second, the second light emitting element submount structure that is sandwiched third radiating substrate Are arranged alternately in a staggered pattern, and the second light-emitting element submount is provided on the back surface of the second heat dissipation substrate in contact with or in contact with the first light-emitting element submount structure. A light-emitting device characterized in that no structure is disposed .

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