JP2013197119A - Semiconductor light-emitting device - Google Patents

Abstract

Embodiments provide a semiconductor light emitting device with high output and high reliability.
A semiconductor light emitting device according to an embodiment includes a first main surface and a second main surface opposite to the first main surface, wherein the first main surface and the first main surface A substrate provided with a groove on any one of the second main surfaces; and a plurality of semiconductor light sources mounted on the first main surface of the substrate. Each of the plurality of semiconductor light sources includes a first lead frame, a semiconductor light emitting element fixed to an upper surface of the first lead frame, and the first lead frame, and is arranged in parallel with the first lead frame via a metal wire. A second lead frame electrically connected to the semiconductor element; and a transparent resin that seals the first lead frame, the semiconductor light emitting element, and the second lead frame.
[Selection] Figure 1

Description

  Embodiments relate to a semiconductor light emitting device.

  A semiconductor light source typified by a light emitting diode (LED) has low power consumption and a long lifetime, and is becoming widespread as a light source replacing a fluorescent lamp and a light bulb. For example, an LED is a light source that is small and easy to handle, but a single light output is not sufficient. For this reason, development of a semiconductor light-emitting device in which a plurality of LEDs are mounted on a substrate is underway.

  On the other hand, many LEDs are housed in a resin package in which a transparent resin for sealing a chip and an envelope surrounding the LED are combined. This is because the light distribution can be controlled by the envelope that reflects the emitted light of the LED, and the light output can be improved.

  However, the polyamide-based thermoplastic resin frequently used for the envelope has a problem in resistance to heat and light. That is, when a plurality of LEDs are mounted, the envelope may deteriorate due to light and heat emitted from the LEDs, and the light output may decrease. Therefore, there is a need for a semiconductor light emitting device with high output and high reliability.

JP 2007-81074 A

  Embodiments provide a semiconductor light emitting device with high output and high reliability.

  The semiconductor light emitting device according to the embodiment includes a first main surface and a second main surface opposite to the first main surface, and the first main surface and the second main surface. A substrate provided with a groove on one of the surfaces; and a plurality of semiconductor light sources mounted on the first main surface of the substrate. Each of the plurality of semiconductor light sources includes a first lead frame, a semiconductor light emitting element fixed to an upper surface of the first lead frame, and the first lead frame, and is arranged in parallel with the first lead frame via a metal wire. A second lead frame electrically connected to the semiconductor element; and a transparent resin that seals the first lead frame, the semiconductor light emitting element, and the second lead frame.

1 is a perspective view schematically showing a semiconductor light emitting device according to an embodiment. It is a perspective view showing a semiconductor light source concerning an embodiment typically. 1 is a partial cross-sectional view schematically showing a semiconductor light emitting device according to an embodiment. 5 is a flowchart showing a manufacturing process of the semiconductor light emitting device according to the embodiment. It is a schematic cross section showing the mounting process of the semiconductor light emitting device according to the embodiment. It is a top view showing the semiconductor light-emitting device concerning the modification of embodiment.

  Hereinafter, embodiments will be described with reference to the drawings. In addition, the same number is attached | subjected to the same part in drawing, the detailed description is abbreviate | omitted suitably, and a different part is demonstrated.

  FIG. 1 is a perspective view schematically showing a semiconductor light emitting device 100 according to the embodiment. The semiconductor light emitting device 100 includes a substrate 10 and a plurality of semiconductor light sources 20 mounted on the substrate 10, and is used, for example, as a light emitting unit of a lighting fixture.

  The substrate 10 has a first main surface 10a and a second main surface 10b opposite to the first main surface 10a. And as shown to Fig.1 (a), the several semiconductor light source 20 is mounted on the 1st main surface 10a. Four recesses 13 are provided on the outer edge of the substrate 10 and can be fixed to the housing of the lighting fixture by screws, for example.

  FIG. 1B is a perspective view showing the second main surface 10 b of the substrate 10. As shown in the drawing, a groove 15 is provided in the second main surface 10b, and for example, warpage due to heat generation of the semiconductor light source 20 is reduced.

  In the present embodiment, nine semiconductor light sources 20 are mounted on the substrate 10. For example, several tens or more than 100 semiconductor light sources 20 may be mounted. As the number of semiconductor light sources 20 increases, the area of the substrate 10 also increases and becomes thicker. As the number of semiconductor light sources 20 increases, the amount of heat generated increases, and the substrate 10 tends to warp. Therefore, by providing the groove 15, it is possible to absorb the warp and reduce the stress, and it becomes easy to correct the substrate that has warped.

  In the present embodiment, the groove 15 is provided on the second main surface 10b, but may be provided on the first main surface 10a. The groove 15 is preferably provided on one of the first main surface 10a and the second main surface 10b.

  FIG. 2 is a perspective view schematically showing the semiconductor light source 20 according to the embodiment. FIG. 2A shows the structure viewed from above (light emitting surface side), and FIG. 2B shows the structure viewed from the side.

  As shown in FIG. 2A, the semiconductor light source 20 includes a first lead frame 21 and a second lead frame 23 (hereinafter referred to as lead frames 21 and 23). The lead frame 21 and the lead frame 23 are juxtaposed on the same surface. On the upper surface of the lead frame 21, an LED chip 25 and an LED chip 27, which are semiconductor light emitting elements, are mounted. The LED chips 25 and 27 are fixed to the surface of the lead frame 21 via, for example, a silver (Ag) paste 31.

  The LED chips 25 and 27 are, for example, blue LEDs made of a nitride semiconductor formed on a sapphire substrate, and have a p-electrode and an n-electrode on the upper surface (not shown). Then, for example, the respective p electrodes and the lead frame 23 are electrically connected via the metal wires 33 and 39. Each n electrode is electrically connected to the lead frame 21 via metal wires 34 and 35.

  Further, a protection diode 29 is provided on the upper surface of the lead frame 23. The protection diode 29 is, for example, a Zener diode, and is electrically connected to the lead frame 21 via the metal wire 37. The protection diode 29 protects the LED chips 25 and 27 from an overcurrent caused by a surge or the like.

  On the upper surface of the lead frame 21, grooves 41 and 42 for preventing the flow of adhesive are provided. The grooves 41 and 42 prevent the adhesive that fixes the LED chips 25 and 27, for example, Ag paste, from spreading to the bonding regions of the metal wires 34, 35, and 37, and ensures the bonding strength of each metal wire.

  Further, suspension pins 43 and 45 are provided on the outer periphery of the lead frames 21 and 23. The suspension pins 43 and 45 are cut when the individual semiconductor light sources 20 are separated from a lead frame sheet (not shown).

  The lead frames 21 and 23 and the LED chip mounted on each of them are sealed with a transparent resin 40. The transparent resin 40 includes a phosphor that is excited by light emitted from the LED chips 25 and 27 and emits yellow fluorescence, for example. Thereby, the semiconductor light source 20 emits white light obtained by combining the blue light of the LED chips 25 and 27 and the yellow light of the phosphor.

  As shown in FIGS. 2A and 2B, the transparent resin 40 is formed in a rectangular parallelepiped, and for example, the upper surface 40a is a light emitting surface. The back surface 21 b of the lead frame 21 and the back surface 23 b of the lead frame 23 are exposed on the back surface 40 b of the transparent resin 40.

  As described above, the semiconductor light source 20 has a simple structure in which the lead frames 21 and 23 on which the LED chips 25 and 27 are mounted are sealed with the transparent resin 40. For this reason, it is easy to reduce the size, and the heat generated by the LED chips 25 and 27 can be efficiently discharged through the back surface 21 b of the lead frame 21. Thereby, it is possible to mount with higher density than an LED light source having an envelope, and high light output and reliability can be realized.

  FIG. 3 is a partial cross-sectional view schematically showing the semiconductor light emitting device 100 according to the embodiment. FIG. 3A shows an example using the insulating substrate 10, and FIG. 3B shows an example using the conductive substrate 60.

  As shown in FIG. 3A, the substrate 10 includes an insulating base material 51 and wirings 53 and 54 provided on the base material 51. For the substrate 51, for example, resin or ceramic can be used.

  Ceramic has higher thermal conductivity than resin, and can improve heat dissipation and dielectric strength. The resin base material is cheaper than ceramics, has excellent processability, and is advantageous for cost reduction.

  The semiconductor light source 20 is mounted on the wirings 53 and 54 provided on the first main surface 10a. The lead frame 21 exposed on the back side of the transparent resin 40 is connected to the wiring 55, and the lead frame 23 is connected to the wiring 57. For bonding the lead frames 21 and 23 and the wirings 55 and 57, for example, conductive paste such as Ag paste or solder is used.

  Furthermore, for example, Ag plating is applied to the surfaces of the wirings 55 and 57 to reflect light emitted from the semiconductor light source 20. Therefore, a resist 59 is provided on the wirings 55 and 57n. As a result, the surfaces of the wirings 55 and 57 can be protected from the outside air, and a decrease in reflectance can be suppressed.

  A groove 15 is provided on the back side of the substrate 10. As shown in FIG. 3A, the groove 15 has, for example, a V shape in a cross section perpendicular to the extending direction thereof. The cross section of the groove 15 may be U-shaped or square.

  As shown in FIG. 3B, a substrate 60 including a conductive base material 61 can be used. The substrate 60 includes a base material 61 and an insulating layer 65 provided on the upper surface thereof. The base material 61 is, for example, a metal base such as aluminum or stainless steel and has a second main surface 60b. The groove 15 is provided in the second main surface 60b. The shape of the groove 15 may be, for example, a V shape, a U shape, or a square shape.

  The upper surface of the insulating layer 65 is a first main surface 60a, and wirings 55 and 57 are provided. The semiconductor light source 20 is mounted on the wirings 55 and 57.

  By using a metal base as the substrate 61, the heat of the semiconductor light source 20 can be efficiently radiated through the thin insulating layer 65. Thereby, the reliability of the semiconductor light source 20 can be improved.

  Next, a method for manufacturing the semiconductor light emitting device 100 will be described with reference to FIG. FIG. 4 is a flowchart showing a manufacturing process of the semiconductor light emitting device according to the embodiment.

  First, lead frames 21 and 23 are prepared (S01). The lead frames 21 and 23 are formed, for example, by selectively etching a copper or copper alloy sheet. That is, a lead frame sheet including a plurality of lead frames 21 and 23 is provided. The plurality of lead frames 21 and 23 are formed in a state of being connected via the suspension pins 43 and 45. Further, Ag plating is applied to the surface of the lead frame sheet.

  Next, the LED chips 25 and 27 are mounted on the lead frame 21, and the protective diode 29 is mounted on the lead frame 23 (S02). As a die mount material for the LED chips 25 and 27, for example, a conductive paste (Ag paste) or an insulating paste can be used. For the die mount material of the protection diode 29, for example, a conductive paste is used. Further, solder and eutectic solder may be used for the die mounts of the LED chips 25 and 27 and the protection diode 29.

  Subsequently, the die mount material is cured, and the LED chips 25 and 27 and the protection diode 29 are fixed to the lead frames 21 and 23, respectively (S03).

  Next, wire bonding is performed to connect the LED chips 25 and 27 to the lead frames 21 and 23, respectively (S04). Further, the protection diode 29 is connected to the lead frame 21.

  Next, the transparent resin 40 is molded on the upper surface of the lead frame sheet to which the LED chips 25 and 27 and the protection diode 29 are fixed (S05). For example, the transparent resin 40 is uniformly molded on the lead frame sheet using a vacuum forming method. Subsequently, the transparent resin 40 is cured and cured (06).

  The transparent resin 40 is, for example, silicone and disperses the phosphor. The phosphor is excited by the blue light emitted from the LEDs 25 and 27 and emits yellow fluorescence, or the phosphor emitting red light and the phosphor emitting green light may be mixed and dispersed. . When using three LED chips that emit light of three colors of blue, green, and red, the transparent resin 40 does not include a phosphor, and a light scattering material may be dispersed.

  Next, the transparent resin 40 and the lead frame sheet are diced and separated into individual semiconductor light sources 20. For example, the transparent resin 40 is cut into a rectangular parallelepiped shape using a dicing blade (S07).

  Next, the characteristics of the semiconductor light source 20 are inspected, and those satisfying a predetermined standard are selected as non-defective products (S08). Subsequently, a plurality of semiconductor light sources 20 are mounted on the substrate 10 (S09). For example, mounting may be performed using a conductive paste, or solder reflow may be used.

  As described above, the semiconductor light source 20 is formed by mounting the light emitting element on the lead frame and performing one resin molding. Therefore, in the semiconductor light source 20, the resin package can be easily downsized and can be mounted on the substrate 10 with high density. In addition, since the manufacturing process is simplified as compared with an LED having an envelope, the manufacturing cost can be reduced.

  FIG. 5 is a schematic cross-sectional view illustrating the mounting process of the semiconductor light emitting device 100 according to the embodiment. The semiconductor light emitting device 100 is mounted on the housing 70 of the lighting fixture using, for example, screws 71.

  As shown in FIG. 5A, the semiconductor light emitting device 100 is mounted in a state of being in close contact with the housing 70 as shown in FIG. 5B even if the substrate 10 is warped before mounting. Can do. That is, the groove 15 provided on the second main surface 10 b of the substrate 10 relaxes the warpage, and the substrate 10 is brought into close contact with the upper surface of the housing 70.

  Further, as shown in FIG. 5B, the stress generated in the substrate 10 due to heat generated by the semiconductor light source 20 can be reduced by the grooves 15 in a state where the semiconductor light emitting device 100 is mounted on the housing 70. And the curvature of the board | substrate 10 can be suppressed and the state closely_contact | adhered to the housing | casing 70 can be maintained. As a result, the heat of the semiconductor light source 20 can be efficiently dissipated, and the reliability of the semiconductor light emitting device 100 can be improved.

  FIG. 6 is a plan view illustrating a semiconductor light emitting device according to a modification of the embodiment. The grooves 15 formed in the second main surface 10b of the substrate 10 are not limited to the example shown in FIG. 1B, but may be formed in the patterns shown in FIGS. 6A to 6C, for example. good.

  In FIG. 6A, a plurality of grooves 15a are provided on each of the upper and lower sides and the left and right sides in the figure. Further, as shown in FIG. 6B, grooves 15 b may be provided radially from the center of the substrate 10. Furthermore, as shown in FIG. 6C, a groove 15c may be provided concentrically with the center of the substrate 10 as the center.

  As described above, the embodiment realizes a high-power semiconductor light emitting device by mounting the semiconductor light source 20 having a resin package with a simple configuration without providing an envelope at high density. And the reliability of a semiconductor light source is improved by molding a semiconductor light emitting element using resin with high heat resistance and light resistance. Further, by providing a groove in the substrate, the warpage is alleviated and the heat radiation is improved. Thereby, a semiconductor light emitting device with high output and high reliability is realized.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10, 60 ... Board | substrate, 10a, 60a ... 1st main surface, 10b, 60b ... 2nd main surface, 13 ... Recessed part, 15, 15a, 15b, 15c ... Groove, 20 ... Semiconductor light source 21, 23 ... Lead frame, 21b, 23b ... Back side, 25, 27 ... LED chip, 29 ... Protection diode, 31 ... Ag paste, 33, 34 , 37, 39 ... Metal wire, 40 ... Transparent resin, 40a ... Upper surface, 40b ... Back surface, 41, 42 ... Groove, 43, 45 ... Hanging pin, 51, 61 ..Substrate, 53, 55, 57 ... wiring, 59 ... resist, 65 ... insulating layer, 70 ... housing, 71 ... screw, 100 ... semiconductor light emitting device

Claims (7)

A first main surface and a second main surface opposite to the first main surface, and a V-groove is provided on either the first main surface or the second main surface. A printed circuit board,
A plurality of semiconductor light sources mounted on the first main surface of the substrate;
With
Each of the plurality of semiconductor light sources is
A first lead frame;
A semiconductor light emitting element fixed to the upper surface of the first lead frame;
A second lead frame arranged in parallel to the first lead frame and electrically connected to the semiconductor element via a metal wire;
A transparent resin containing a phosphor that seals the first lead frame, the semiconductor light emitting element, and the second lead frame and is excited by the emitted light of the semiconductor light emitting element;
A semiconductor light emitting device. A first main surface and a second main surface opposite to the first main surface, and a groove is provided on either the first main surface or the second main surface. A substrate,
A plurality of semiconductor light sources mounted on the first main surface of the substrate;
With
Each of the plurality of semiconductor light sources is
A first lead frame;
A semiconductor light emitting element fixed to the upper surface of the first lead frame;
A second lead frame arranged in parallel to the first lead frame and electrically connected to the semiconductor element via a metal wire;
A transparent resin encapsulating the first lead frame, the semiconductor light emitting element, and the second lead frame;
A semiconductor light emitting device.   The semiconductor light-emitting device according to claim 2, wherein the transparent resin includes a phosphor that is excited by emitted light of the semiconductor light-emitting element.   The semiconductor light-emitting device according to claim 2, wherein the groove has a V shape in a cross section perpendicular to the extending direction thereof.   The semiconductor light-emitting device according to claim 2, wherein the groove is provided on the second main surface side.   The said board | substrate contains the metal base which has the said 2nd main surface, and the insulating layer provided in the said 1st main surface side and on the upper surface of the said metal base. The semiconductor light-emitting device described in 1.   The semiconductor light-emitting device according to claim 2, wherein the substrate includes ceramic.

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