JP2012069577A - Semiconductor light-emitting device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that it is difficult to simply mass-produce an LED light-emitting device having excellent light emission efficiency and light emission characteristics (one binned) in a conventional production method of the LED light-emitting device.SOLUTION: The LED light-emitting device 10 is formed by mounting LEDs 3 on a circuit board 2, forming a light scattering layer 7 on side surfaces of the LEDs 3, and forming a phosphor layer 5a on the upper surfaces of the LEDs 3 and the light scattering layer 7. The upper surfaces of the LEDs 3 and the upper surface of the light scattering layer 7 form almost the same surface.

Description

  The present invention relates to a semiconductor light emitting device including a semiconductor light emitting element such as an LED element and a method for manufacturing the same.

  In recent years, since an LED element (hereinafter abbreviated as LED) is a semiconductor element, it has a long life and excellent driving characteristics, is small in size, has high luminous efficiency, and has a bright emission color. Widely used for backlights and lighting. In the present invention, an LED light emitting device will be described as an embodiment.

  In particular, in recent years, many light sources constituting LED light emitting devices of various emission colors by combining LEDs and phosphor layers such as phosphor resins have been commercialized. For example, white LED light emitting devices by combining blue LEDs and YAG fluorescent resins Is widely adopted. (For example, cited reference 1)

  Hereinafter, the LED light emitting device combining the conventional LED and the phosphor resin in the cited document 1 will be described. FIG. 6 is a cross-sectional view of a main part of a conventional LED light emitting device 100 in the cited document 1, and is shown in a simplified manner within a range not changing the gist of the invention. In FIG. 6, the LED light emitting device 100 seals an LED 103 flip chip mounted (hereinafter abbreviated as FC mounting) on a circuit board 102 with a fluorescent resin 105 using a reflection frame 104 provided on the circuit board 102. . Reference numerals 103a and 103b denote bump electrodes provided on the LED 3, and the LED 3 is FC-mounted on the wiring electrodes (not shown) on the circuit board 102 by the bump electrodes 103a and 103b.

  Next, the light emission operation of the LED light emitting device 100 will be described. The distance in the fluorescent resin 105 through which the radiated light emitted from the LED 103 passes until it is emitted at the light emission position from the LED 103, such as P1, P2, and P3, changes. Thus, the emitted light from the LED 103 is affected by the distance passing through the fluorescent resin 105, and the chromaticity changes. For this reason, since the distance in the fluorescent resin 105 that passes between the emitted light P1 emitted above the LED 103 and the emitted lights P2 and P3 emitted to the side of the LED 103 is greatly different in one LED 103, the emitted light P1 and When the intensity ratio of P2 and P3, that is, the radiant flux upward and laterally of the LED 103 varies, the chromaticity of the LED light emitting device also varies. As a result, it becomes difficult for the LED light emitting device 100 to be binned (contained in the region range in the chromaticity diagram).

  In addition, when a plurality of LED light emitting devices 100 are mass-produced, each LED light emitting device 100 has a difference in thickness of the fluorescent resin 105 to be sealed in addition to variations in the thickness of each LED light emitting device 100 and the mounting height. Since there is also a chromaticity change for each LED light emitting device 100, it is more difficult to make a mass-produced product into one bin.

In the LED light emitting device 100 shown in the above cited document 1, a method for improving the chromaticity change due to the difference in the distance of the fluorescent resin through which light emitted from the LED passes has been proposed. (For example, cited document 2)
Hereinafter, the LED light emitting device combining the conventional LED and the phosphor resin in the cited document 2 will be described.

  FIG. 7 is a cross-sectional view of a main part of a conventional LED light emitting device 200 in the cited document 2. In FIG. 7, the LED light emitting device 200 is provided with two lead members, that is, a mount lead 202a and an inner lead 202b. The LED 203 fixed in the cup of the mount lead 202a is mounted by wire bonding to the mount lead 202a and the inner lead 202b by wires 203a and 203b, respectively.

  The mounted LED 203, the mount lead 202a, and the inner lead 202b are molded into a bullet shape with a transparent resin 206 mixed with a transparent resin or a light diffusing material, and further, on the surface of the transparent resin 206 molded into the bullet shape. The fluorescent resin 205 is coated with a constant thickness.

  Next, the light emission operation of the LED light emitting device 200 will be described. The emitted light emitted from the LED 203 travels inside the transparent resin 206, passes through the fluorescent resin 205 coated on the surface of the transparent resin 206, and is emitted as emitted light Ps. All the emitted light Ps is hardly attenuated in the progress in the transparent resin 206, and the fluorescent resin 205 coated on the surface of the transparent resin 206 is coated with a certain thickness. By passing (having the same optical path length through the fluorescent resin), they all have the same chromaticity.

  Furthermore, what paid attention to the member arrangement | positioning of a LED light-emitting device is also proposed (for example, cited reference 3). Cited Document 3 shows an LED light emitting device in which only a side surface side is covered with a phosphor layer without arranging a light blocking member on the light emitting surface side of the LED. This LED light-emitting device uses the fact that the light emitted from the phosphor layer can be only light emitted from the fluorescent resin, and specifies the location of the fluorescent resin to suppress chromaticity variation between the LED light-emitting devices. It is an object.

Japanese Patent Laid-Open No. 10-242513 Japanese Patent Laid-Open No. 10-200165 JP 2003-249689 A

  However, in the LED light emitting device shown in the cited document 3, all the blue light emitted from the side surface side of the LED passes through a long optical path length on average, so that all the wavelengths are converted. In this method, the chromaticity varies depending on the ratio of the radiant flux emitted from the upper side and the side of the LED as in the LED light emitting device 100 of FIG. In addition, passing through a long optical path length has a problem that light loss due to absorption other than wavelength conversion also increases, resulting in a decrease in luminous efficiency.

  As described above, the LED light emitting device 100 of Patent Document 1 and the LED light emitting device of Patent Document 3 are better in terms of light emission efficiency and one bin of chromaticity. It can be said that it is excellent.

  However, the LED light emitting device 200 in the above cited document 2 is excellent in uniforming the chromaticity, that is, making it into one bin, by passing all the emitted light through the fluorescent resin 205 at the same distance. There is a problem that it is not suitable for mass production because it has a complicated shape like the shell type provided. That is, since the shape is a complicated three-dimensional shape, it is difficult to coat the surface of the transparent resin with the fluorescent resin to a uniform thickness, and further, it is difficult to reduce the cost by mass production.

  Accordingly, an object of the present invention is to solve the above-mentioned problems, and by making the optical path lengths of all the radiated light from the LED through the fluorescent resin the same, it is possible to make one bin by uniformizing the chromaticity. An object of the present invention is to provide an LED light-emitting device and a method for manufacturing the LED light-emitting device that can be easily manufactured while reducing the attenuation of light emission from the LED to increase the light emission efficiency.

  In order to achieve the above object, an LED light emitting device according to the present invention includes a semiconductor light emitting device mounted on a circuit board, a light scattering layer is formed on a side surface of the semiconductor light emitting device, and the semiconductor light emitting device and the light scattering layer are formed. A semiconductor light emitting device having a phosphor layer formed on an upper surface, wherein the upper surface of the semiconductor light emitting element and the upper surface of the light scattering layer form substantially the same surface.

  According to the above configuration, the upper surface of the semiconductor light emitting element and the upper surface of the light scattering layer are formed on substantially the same plane, and the phosphor layer having a uniform thickness is formed on the upper surface. Both the light emitted from the upper surface of the element and the emitted light emitted from the side surface of the semiconductor light emitting element and passed through the light scattering layer pass through the phosphor layer having a uniform thickness with the same optical path length. A single bin can be easily achieved without being affected by the ratio of the radiant flux between the upper surface and the side surface of the light emitting element. In addition, since the light emitted from the LED is directly incident on the upper surface side and incident on the phosphor layer through the light scattering layer with less attenuation on the side surface side, the attenuation from the light emission to the emitted light can be suppressed as much as possible. High luminous efficiency can be obtained. In addition, since the semiconductor light emitting element and the upper surface of the light scattering layer are substantially the same surface, a process based on a coating method can be applied, and thus manufacturing is facilitated.

  The semiconductor light emitting element is preferably flip-chip mounted on a circuit board.

  A transparent resin layer is preferably laminated on the phosphor layer formed on the semiconductor light emitting element and the light scattering layer.

  The transparent resin layer is formed in two layers, a first transparent resin layer and a second transparent resin layer, and the first transparent resin layer and the second transparent resin layer are respectively laminated on both sides of the phosphor layer. Good to be.

  In order to achieve the above object, a manufacturing method according to the present invention includes a mounting step of flip-chip mounting a plurality of semiconductor light emitting elements on a large circuit board at a predetermined interval, and a plurality of flip-chip mountings on the circuit board. A light scattering layer forming step of forming a light scattering layer up to a height covering the semiconductor light emitting device, a polishing step of polishing the light scattering layer to the same height as the upper surface of the semiconductor light emitting device, and a polished light scattering layer; It has a phosphor layer forming step of forming a phosphor layer on the upper surface of the semiconductor light emitting element, and a cutting step of separating and forming a semiconductor light emitting device by cutting the circuit board.

  After the phosphor layer forming step, a groove processing step of forming a groove by cutting the phosphor layer and the light scattering layer at a predetermined width at both ends of each semiconductor light emitting element; and a reflective resin in the groove It is preferable to further include a reflection frame forming step of forming a reflection frame by injecting, and cutting the circuit board while leaving the reflection frame in the cutting step.

  According to the above manufacturing method, a light scattering layer forming step of forming a light scattering layer up to a height that covers a plurality of semiconductor light emitting elements flip-chip mounted on a large circuit board; By providing a polishing step for polishing to the same height as the upper surface of the device, the upper surface of the semiconductor light emitting device and the upper surface of the light scattering layer can be easily formed at the same height, and a uniform thickness on this same height surface. The phosphor layer can be formed.

  Moreover, according to the said manufacturing method, LED light-emitting devices with high luminous efficiency can be mass-produced easily, achieving 1 bin easily.

  As described above, in the LED light emitting device of the present invention, the light scattering layer is formed only on the side surface, and the phosphor layer is formed on the upper surface of the LED and the light scattering layer. As a result, both the light emitted from the upper surface of the LED and the emitted light emitted from the side surface of the LED and passed through the light scattering layer pass through the phosphor layer having a uniform thickness with the same optical path length. Can be easily achieved. In addition, light emitted from the LED passes through the light scattering layer with low attenuation directly from the upper surface side and enters the phosphor layer from the side surface side, so that attenuation from light emission to emitted light can be suppressed as much as possible. And high luminous efficiency can be obtained. Furthermore, it can be easily manufactured by a process mainly comprising a coating method.

  As described above, according to the manufacturing method of the present invention, light emission on the side surface side of the LED can be efficiently used, and an LED light emitting device with high light emission efficiency can be easily mass-produced while easily achieving one bin.

It is sectional drawing which shows the structure of the LED light-emitting device in 1st Embodiment of this invention. It is process drawing which shows the manufacturing method of the LED light-emitting device shown in FIG. It is sectional drawing which shows the structure of the LED light-emitting device in 2nd Embodiment of this invention. It is process drawing which shows the manufacturing method of the LED light-emitting device shown in FIG. It is sectional drawing which shows the structure of the LED light-emitting device in 3rd Embodiment of this invention. It is sectional drawing which shows the structure of the conventional LED light-emitting device. It is sectional drawing which shows the structure of the conventional LED light-emitting device.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part of an LED light emitting device according to a first embodiment of the present invention, and FIG. 2 is a process diagram showing a method for manufacturing the LED light emitting device shown in FIG.

(Description of configuration of LED light emitting device in first embodiment)
Hereinafter, the configuration of the LED light emitting device according to the first embodiment of the present invention will be described. In FIG. 1, the LED light emitting device 10 has an LED 3 mounted on the circuit board 2 by FC with bump electrodes 3 a and 3 b. (The wiring electrodes on the circuit board 2 are not shown in the figure.) Inside the reflection frame 4 provided on the circuit board 2, the light scattering resin 7 is filled on the side surface side of the LED 3 to form a light scattering layer 7. The light scattering layer 7 is formed at the same height as the upper surface of the LED 3. That is, the upper surface formed by the light scattering layer 7 and the LED 3 is the same surface.
Further, the phosphor layer 5a is formed on the same surface formed by the light scattering layer 7 and the LED 3 so that the fluorescent resin has a predetermined thickness H.

  Next, the operation of the LED light emitting device 10 will be described. Of the light emitted from the LED 3 of the LED light emitting device 10, light emitted from the upper surface side passes directly through the phosphor layer 5 a and is emitted as emitted light Po 1, and light emitted from the side surface side of the LED 3 travels in the light scattering layer 7. Thereafter, the light is emitted upward as a radiated light Po2 by passing upward through the phosphor layer 5a by a scattering action. In this operation, there is almost no attenuation of light inside the light scattering layer 7 and the thickness of the passing phosphor layer 5a is the same thickness H everywhere, so that the emitted lights Po1 and Po2 have the same color. Therefore, the light source is a binned light source on the entire surface of the LED light emitting device 10.

  According to the above configuration, the light scattering layer 7 and the reflective frame 4 having the same thickness as the LED 3 can effectively use all the light emitted to the side surface of the LED 3 as the emitted light. In particular, since it is within the height of the substrate 2, the LED 3, and the phosphor layer 5a, a thin light source can be configured.

(Description of Manufacturing Process of LED Light Emitting Device in First Embodiment)
Next, a method for manufacturing the LED light emitting device 10 shown in FIG. 1 will be described with reference to FIG.
Process A in FIG. 2 is an LED mounting process. An assembly in which a large circuit board 2L having a wiring pattern (not shown) is prepared, and a plurality of LEDs 3 are mounted at predetermined intervals by FC mounting LEDs 3 on each wiring pattern. Configure. Step B is a light scattering layer forming step, in which the light scattering layer 7 is formed to a height that covers the plurality of LEDs 3 that are FC-mounted on the large circuit board 2L. Step C is a polishing step, in which the light scattering layer 7 formed to a height that covers the LED 3 is polished to the same height as the upper surface of the LED 3. The portion indicated by the dotted line in FIG. C shows the polished light scattering layer 7a. By this polishing step, the upper surface of each LED 3 and the upper surface of the light scattering layer 7 form the same surface, and the flat surface is formed on the upper surface of the aggregate Is formed. Step D is a phosphor layer forming step, in which the phosphor resin 5 is applied to a constant thickness on the flat surface of the upper surface of the aggregate formed by the polishing step, thereby forming the phosphor layer 5a. Step E is a groove processing step, in which grooves 8 are formed at predetermined intervals in the laminated light scattering layer 7 and phosphor layer 5a. Step F is a reflection frame forming step, in which the reflecting frame 4 is formed by filling the grooves 8 provided in the groove processing step with a reflective resin. Step G is a cutting / separating step, in which the light scattering layer 7 and the phosphor layer 5a are cut and separated together with the large circuit board 2L at a position where the reflection frame 4 remains on both sides, and a plurality of LED light emitting devices 10 To complete. The LED light emitting device 10 is the same as the LED light emitting device 10 shown in FIG.

  An example of each configuration of the LED light emitting device 10 will be described. As the LED 3, a blue LED having a light emission wavelength of 445 nm is used in which a light emitting layer and a transparent electrode are formed on a sapphire substrate. The light emission amount of the LED 3 is about 50% from the upper emission surface side and about 50% from the side surface side. Further, a silicone resin mixed with scattering particles such as SiO 2 and alumina is used as the light scattering layer 7, and the fluorescent resin 5 has a thickness of approximately 100 μm, and yellow YAG, green BSS, red CASN, etc. A silicone resin mixed with the above phosphor is used. Further, a substrate material having good reflectivity is used for the circuit board 2 or a treatment for improving the reflectivity is performed on the circuit board 2, and the reflective frame 4 is a reflective particle such as titanium oxide. A white resin with good reflectivity mixed with silicone resin is used. In addition, the fluorescent resin layer is exemplified as the fluorescent material layer, but the fluorescent material layer is not limited to this, and naturally includes a fluorescent material layer in which fluorescent particles are mixed in a glassy inorganic ink and fired.

(Description of configuration of LED light emitting device in second embodiment)
Next, the configuration of the LED light-emitting device according to the second embodiment of the present invention will be described with reference to FIG. The basic configuration of the LED light emitting device 20 in FIG. 3 is the same as that of the LED light emitting device 10 shown in FIG. 1, and the same elements are denoted by the same reference numerals and redundant description is omitted. The LED light emitting device 20 in the second embodiment is different from the LED light emitting device 10 in the first embodiment in that the transparent resin layer 21 is between the flat surface formed on the upper surface of the LED 3 and the light scattering layer 7 and the phosphor layer 5a. And the transparent resin layer 22 is also formed on the upper surface of the phosphor layer 5a.

  The transparent resin layer 21 protects the LED 3 and the light scattering layer 7 and adjusts the gap between the LED 3 and the light scattering layer 7 and the phosphor layer 5a. The transparent resin layer 22 protects the upper surface of the phosphor layer 5a, that is, protects the upper surface of the LED light emitting device 20.

(Description of Manufacturing Process of LED Light Emitting Device in Second Embodiment)
Next, with reference to FIG. 4, a method for manufacturing the LED light-emitting device 20 in the second embodiment of the present invention will be described. The basic steps of the manufacturing process of the LED light emitting device 20 in FIG. 4 are the same as those of the LED light emitting device 10 shown in FIG. 1, and the same steps are denoted by the same reference numerals, and redundant description is omitted. In the manufacturing method of the LED light emitting device 20 in the second embodiment, the process A to the process C are the same as the process A to the process C of the LED light emitting apparatus 10 in the first embodiment.

  Step D is a first transparent resin layer forming step, in which the transparent resin layer 21 is formed on the flat surfaces formed on the upper surfaces of the LED 3 and the light scattering layer 7. Step E is a phosphor layer forming step, in which the phosphor layer 5 a is formed on the upper surface of the transparent resin layer 21. Step F is a second transparent resin layer forming step, in which the transparent resin layer 22 is formed on the phosphor layer 5a. Steps G, H, and I are basically the same steps as steps E, F, and G of the LED light emitting device 10 in the first embodiment, and are a groove processing step G, a reflection frame forming step H, and a cutting and separating step I.

  However, in the groove processing step G in the second embodiment, the first transparent resin light layer 21, the second transparent resin light layer 22, the light scattering layer 7, and the phosphor layer 5 a are laminated at predetermined intervals. 8 is formed. In the reflection frame forming step F, the grooves 8 provided in the groove processing step G are filled with a reflective resin to form the reflection frame 4. In the cutting / separating step I, the first transparent resin light layer 21, the second transparent resin light layer 22, the light scattering layer 7 and the phosphor layer 5a which are laminated are arranged in a large size at the positions where the reflection frames 4 remain on both sides. Each of the circuit boards 2L is cut and separated to complete the plurality of LED light emitting devices 20. The LED light emitting device 20 is the same as the LED light emitting device 20 shown in FIG.

(Description of configuration of LED light emitting device in the third embodiment)
Next, the configuration of the LED light emitting device according to the third embodiment of the present invention will be described with reference to FIG. In the LED light emitting device 30 in FIG. 5, the LED 3 is mounted on the circuit board 2 in the reverse direction, and wire-bonded to the wiring (not shown) on the circuit board 2 by wires 33 a and 33 b. In the LED light emitting device 30, as in the LED light emitting device 20, the LED 3 and the light scattering layer 7 form a flat surface on the circuit board 2, and the transparent resin layer 21 and the phosphor layer 5a are laminated on the flat surface. The transparent resin layer 21 protects the positions and deformations of the wires 33a and 33b. Therefore, in this LED light emitting device 30, as in the LED light emitting device 20, emitted light Po1 and Po2 as light sources are emitted with the same chromaticity and light emission intensity. The light scattering layer 7 and the transparent resin layer 21 are applied with a dispenser. In particular, the light scattering layer 7 is applied with high accuracy.

2,102 Circuit board 3,103,203 LED
3a, 3b, 103a, 103b Bump electrode 4, 104 Reflection frame 105, 205 Fluorescent resin 5a Phosphor layer 7 Light diffusion layer 8 Groove 10, 20, 30, 100, 200 LED light emitting device 33a, 33b, 203a, 203b Wire
202a Mount lead 202b Inner lead P1, P2, P3, Ps, Po1, Po2 Synchrotron radiation

Claims (6)

  A semiconductor light emitting device in which a semiconductor light emitting element is mounted on a circuit board, a light scattering layer is formed on a side surface of the semiconductor light emitting element, and a phosphor layer is formed on an upper surface of the semiconductor light emitting element and the light scattering layer, The semiconductor light emitting device, wherein the upper surface of the semiconductor light emitting element and the upper surface of the light scattering layer form substantially the same plane.   The semiconductor light emitting device according to claim 1, wherein the semiconductor light emitting element is flip-chip mounted on the circuit board.   The semiconductor light-emitting device according to claim 1, wherein a transparent resin layer is laminated on the phosphor layer formed on the semiconductor light-emitting element and the light scattering layer.   The transparent resin layer is formed in two layers, a first transparent resin layer and a second transparent resin layer, and the first transparent resin layer and the second transparent resin layer are respectively laminated on both sides of the phosphor layer. The semiconductor light-emitting device according to claim 3.   A mounting process for flip-chip mounting a plurality of semiconductor light-emitting elements on a large circuit board at a predetermined interval, and a light scattering layer formed to a height that covers the plurality of semiconductor light-emitting elements flip-chip mounted on the circuit board A light scattering layer forming step, a polishing step of polishing the light scattering layer to the same height as the upper surface of the semiconductor light emitting device, and forming a phosphor layer on the upper surface of the polished light scattering layer and the semiconductor light emitting device A method of manufacturing a semiconductor light emitting device, comprising: a phosphor layer forming step; and a cutting step of separating and forming the semiconductor light emitting device by cutting the circuit board. After the phosphor layer forming step, a groove processing step of forming a groove by cutting the phosphor layer and the light scattering layer at a predetermined width at both ends of each semiconductor light emitting element; and a reflective resin in the groove 6. The semiconductor light emitting device according to claim 5, further comprising a reflection frame forming step of forming a reflection frame by injecting, wherein the circuit substrate is cut while leaving the reflection frame in the cutting step. Manufacturing method.

Images