JP2015070132A - Method of manufacturing light-emitting device and light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a light-emitting device capable of ensuring excellent orientation by reducing light leakage from the sides of the upper surface of a light-emitting element, and to provide a light-emitting device.SOLUTION: A method of manufacturing a light-emitting device 100 includes a phosphor layer formation step for forming a phosphor layer 40 containing a phosphor 4 on the surface of a light-emitting element 10, and a small particle part formation step for forming a small particle part 50 containing light reflective particles or light diffusion particles 5 having a particle size smaller than that of the phosphor 4, on the sides of the upper surface of the light-emitting element 10 where the phosphor layer 40 is formed.

Description

  The present invention relates to a method for manufacturing a light emitting device in which a phosphor layer is formed on the surface of a light emitting element, and the light emitting device.

  In general, a light-emitting device using a light-emitting element is known to be small, power efficient, and emit bright colors. Since the light-emitting element according to this light-emitting device is a semiconductor element, the light-emitting element is characterized by not only less fear of ball breakage but also excellent initial drive characteristics and resistance to repeated vibration and on / off lighting. Because of such excellent characteristics, light emitting devices using light emitting elements such as light emitting diodes (LEDs) and laser diodes (LDs) are used as various light sources.

  Here, for example, the most widespread method for producing a white LED is, for an LED element that emits blue light, a yellow phosphor that uses blue light from the LED element as excitation light, and around the light emitting element. It is the method of apply | coating to. In the light emitting device, if the phosphor layer can be formed in a substantially uniform thickness around the LED element, the light emitting device can be a light emitting device having excellent light distribution (same color light seen from any angle). Therefore, in the light emitting device, it is important how to form the phosphor layer with a uniform thickness around the LED element.

  Thus, for example, a technique for forming a phosphor layer having a uniform thickness (uniform phosphor distribution) on an LED element by forming a phosphor layer (wavelength conversion layer) of a light emitting device by a spray coating method is disclosed. (For example, refer to Patent Document 1).

International Publication No. 2013/054658

However, for example, in the conventional technique of forming a phosphor layer on the surface of a light emitting element by a spray coating method, the following problems existed.
When the phosphor layer is formed by a spray coating method, the phosphor layer is less likely to adhere to the side of the top surface of the light emitting element due to the shape of the element. End up. Or the site | part in which a fluorescent substance layer is not formed in a side part will arise. For this reason, the light emitting device has a problem in that light leakage occurs from the side of the upper surface of the light emitting element, and the light distribution is not sufficiently excellent.

  The present invention has been made in view of such problems, and a method for manufacturing a light emitting device and light emission that can have excellent light distribution by reducing light leakage from the side portion of the upper surface of the light emitting element. It is an object to provide an apparatus.

  In order to solve the above problems, a method for manufacturing a light emitting device according to the present invention includes a phosphor layer forming step of forming a phosphor layer containing a phosphor on a surface of a light emitting element, and the phosphor layer is formed. A small particle part forming step of forming a small particle part including light reflecting particles or light diffusing particles having a particle diameter smaller than that of the phosphor on the side part of the upper surface of the light emitting element.

  In addition, in the method for manufacturing a light emitting device according to the present invention, a small particle part forming step of forming a small particle part including light reflecting particles or light diffusing particles on the side part of the upper surface of the light emitting element, and the small particle part is formed. And a phosphor layer forming step of forming a phosphor layer containing a phosphor having a particle size larger than that of the light reflecting particles or the light diffusing particles on the surface of the light emitting element.

  Furthermore, the light-emitting device according to the present invention includes a light-emitting element, a phosphor layer formed on a surface of the light-emitting element, and a phosphor from the phosphor of the phosphor layer formed on a side portion of the upper surface of the light-emitting element. And a small particle portion including light reflecting particles or light diffusing particles having a small diameter.

According to the method for manufacturing a light emitting device according to the present invention, it is possible to manufacture a light emitting device capable of reducing light leakage from the side portion of the upper surface of the light emitting element. Thereby, the light-emitting device excellent in light distribution can be manufactured.
According to the light emitting device of the present invention, by providing the small particle portion including the light reflecting particles or the light diffusing particles having a particle diameter smaller than that of the phosphor on the side portion of the upper surface of the light emitting element, Light leakage can be reduced. Thereby, it becomes a light-emitting device excellent in light distribution.

1 is a perspective view schematically showing a schematic form of a light emitting device according to the present invention. It is sectional drawing which shows typically the form with which the light-emitting device based on this invention was outlined, and is XX sectional drawing of FIG. It is a schematic diagram for demonstrating the pulse type spray using a pulse type spray apparatus. In the manufacturing method of the light-emitting device of this invention, it is a schematic diagram for demonstrating the method in the case of using a mask, (a) is a top view which shows typically the board | substrate which mounted the light emitting element on the mounting board | substrate, (b) ) Is a plan view schematically showing a light emitting element side portion blowing mask, and (c) is a plan view schematically showing a state where the mask is placed on a substrate. FIG. 5 is a schematic diagram for explaining a method in the case of using a mask in the method for manufacturing a light emitting device of the present invention, and is a cross-sectional view taken along line YY in FIG.

  Hereinafter, a method for manufacturing a light emitting device and a form of the light emitting device according to the present invention will be described with reference to the drawings. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Further, in the following description, the same name and reference sign indicate the same or the same members in principle, and the detailed description will be omitted as appropriate.

≪Light emitting device≫
First, the light emitting device of the present invention will be described.
As shown in FIGS. 1 and 2, here, the light emitting device 100 includes a base material 1, conductive members 2a and 2b provided on the base material 1, and bumps 3a and 2b provided on the conductive members 2a and 2b. 3b, the light emitting element 10 provided on the bumps 3a and 3b, the phosphor layer 40 provided on the surface of the light emitting element 10, and the small particle part 50 provided on the side 15 of the upper surface of the light emitting element 10. Is mainly provided. The substrate 1 and the conductive members 2a and 2b constitute a substrate (mounting substrate) 20. For easy understanding of the configuration of the present invention, the phosphor layer 40 and the small particle part 50 shown in FIG. 2 are not shown in FIG.
Each configuration will be described below.

(Mounting board)
As shown in FIGS. 1 and 2, the mounting substrate 20 is a substrate on which electronic components such as the light emitting element 10 are mounted. Here, the base member 1 and the conductive members 2 a and 2 b provided on the base member 1 are used. And comprising.
As shown in FIG. 1, the mounting substrate 20 (or the base material 1) is formed in a rectangular flat plate shape here. In addition, the size and shape of the mounting substrate 20 (or the base material 1) are not particularly limited, and can be appropriately selected according to the purpose and application such as the number of light emitting elements 10 and the arrangement interval.

[Base material]
The base material 1 is a member on which electronic components such as the light emitting element 10 are mounted via the conductive members 2a and 2b.
As the material of the base material 1, it is preferable to use an insulating material, and it is preferable to use a material that hardly transmits light emitted from the light emitting element 10 or external light. Moreover, it is preferable to use a material having a certain degree of strength. Specific examples include ceramics (Al ₂ O ₃ , AlN, etc.) or a resin, or a member provided with an insulating layer on the surface of a metal plate. Among ceramics, low-temperature sintered ceramics (LTCC) can be preferably used because it easily increases the light reflectance.

[Conductive member]
The conductive members 2a and 2b are members for electrically connecting the outside and electronic components such as the light emitting element 10 and supplying electric current (power) from the outside to these electronic components.
The material of the conductive members 2a and 2b can be appropriately selected depending on the material used as the base material 1 described above, the manufacturing method of the light emitting device 100, and the like. For example, metals such as copper, aluminum, gold, silver, tungsten, iron, and nickel, or iron-nickel alloys, phosphor bronze, iron-containing copper, molybdenum, and the like can be given.

  The conductive members 2a and 2b also have a function as a heat dissipation path. In order to improve heat dissipation, it is preferably provided in a wide area. For example, it is provided in a wide width with respect to the short direction of the substrate 1 (for example, the direction in which the sides a and c of the upper surface of the light emitting element 10 extend). It is preferred that

[bump]
The bumps 3a and 3b are members that electrically connect the electrodes of the light emitting element 10 and the conductive members 2a and 2b.
A conventionally well-known thing should just be used as a bump, For example, a stud bump and a plating bump are mentioned. As a material of the stud bump, Au or an alloy thereof is often used. As the material of the plating bump, only Au or a laminated structure in which the surface is Au based on Cu or Ni is used.

[Light emitting element]
The light emitting element 10 has, for example, positive and negative electrode pads on the surface opposite to the light emitting surface (the lower surface of the growth substrate 13 in FIG. 2), and is connected to the conductive members 2a and 2b via the bumps 3a and 3b. And mounted on the substrate 1. Here, the n-side electrode connected to the semiconductor layer 11 is connected to the conductive member 2a which is a negative electrode through the bump 3a, and the p-side electrode connected to the semiconductor layer 12 is connected to the positive electrode through the bumps 3b and 3b. Is connected to the conductive member 2b. The light emitting surface is a surface on the light extraction direction side of the light emitting device 100 on the side opposite to the surface facing the base material 1 when mounted on the mounting substrate 20.

As the light emitting element 10, a light emitting diode having a semiconductor layer including a side portion on the upper surface, for example, a substantially rectangular parallelepiped shape, and having an n layer, a p layer, and an active layer that emits light can be used. An arbitrary wavelength can be selected. For example, as the light emitting element 10 of blue (light having a wavelength of 430 nm to 490 nm) and green (light having a wavelength of 490 nm to 570 nm), ZnSe, nitride semiconductor (In _X Al _Y Ga _1-XY N, 0 ≦ X , 0 ≦ Y, X + Y ≦ 1), GaP, or the like can be used. As the red light emitting element 10 (light having a wavelength of 620 nm to 750 nm), GaAlAs, AlInGaP, or the like can be used.

Note that in the case of the light emitting device 100 using a fluorescent material, a nitride semiconductor (In _X Al _Y Ga _1- XYN, 0 ≦ X that can emit light with a short wavelength that can efficiently excite the fluorescent material). , 0 ≦ Y, X + Y ≦ 1) are preferably used. The emission wavelength can be variously selected by adjusting the material of the active layer and its mixed crystal. Furthermore, the light emitting element 10 made of a material other than these can also be used. Note that the component composition, emission color, size, number, and the like of the light-emitting element 10 to be used can be appropriately selected depending on the purpose.
The light-emitting element 10 preferably has a light-transmitting substrate such as sapphire on the light extraction surface side. Further, the light-emitting element 10 that outputs not only visible light but also ultraviolet rays and infrared rays may be used.
The light emitting device 100 can be a white LED element by combining a blue light emitting element and a yellow phosphor.

  In the present invention, the light emitting element 10 may be configured not to have the growth substrate 13. For example, after growing a semiconductor layer composed of an n layer, an active layer and a p layer on the growth substrate 13, for example, by a laser lift-off method, a metric method (MeTRe method; Mechanical Transfer using a Release layer), a chemical lift-off method, etc. The growth substrate 13 may be peeled off from the semiconductor layer.

[Phosphor layer]
The phosphor layer 40 is a layer including the phosphor 4 formed on the surface of the light emitting element 10, and covers the surface of the light emitting element 10. The phosphor layer 40 is also formed on the upper surface of the base material 1 other than the part where the light emitting element 10 is placed. The phosphor layer 40 is formed, for example, by applying a slurry in which the phosphor 4, a resin, and a solvent are mixed. The phosphor layer 40 may be mixed with a resin or the like, or may be formed only of the phosphor 4. In FIG. 2, it is assumed that the phosphor layer 40 contains a resin or the like (not shown). When the phosphor layer 40 contains a resin, the small particles 5 are easily fixed to the side portion 15.
The thickness of the phosphor layer is about 10 μm to 200 μm.
As described above, the phosphor layer is not formed on the sides or corners of the light-emitting element, and thus the phosphor layer is not formed or formed thinner than the other portions. A small particle portion described later is formed in a portion where the phosphor layer is not formed or a portion where the phosphor layer is thin.
The phosphor 4 constituting the phosphor layer 40 is a fluorescent member that emits light having a different wavelength by absorbing at least part of the light from the light emitting element 10 as a wavelength conversion member.

Examples of the material of the phosphor 4 include a YAG phosphor in which yttrium, aluminum and garnet are mixed, and a nitride phosphor and an oxynitride phosphor mainly activated by a lanthanoid element such as Eu or Ce. Etc. can be used. For example, in a blue light emitting element, a combination with a silicate phosphor of YAG phosphor, LuAG phosphor, M ₂ SiO ₄ : Eu (M is Sr, Ca, Ba, etc.) emitting green to yellow, In order to enhance color rendering properties, phosphors that emit red light include SCASN phosphors such as (Sr, Ca) AlSiN ₃ : Eu, CASN phosphors such as CaAlSiN ₃ : Eu, SrAlSiN ₃ : Eu, A KSF phosphor or the like is used in a combination or blending ratio suitable for a desired color tone.

  The particle diameter of the phosphor 4 is not particularly defined as long as it is larger than the particle diameter of the light reflecting particles or light diffusing particles (hereinafter referred to as small particles) 5 constituting the small particle portion 50. As an example, it is 3-30 micrometers.

[Small particle part]
The small particle part 50 is a part (or layer) containing light reflecting particles or light diffusing particles formed on the side part 15 on the upper surface of the light emitting element 10 and covers the side part 15 on the upper surface of the light emitting element 10. It is. The small particle portion 50 is formed, for example, by applying a slurry in which the small particles 5, a resin, and a solvent are mixed. In addition, the small particle part 50 may be mixed with resin or the like, or may be formed only by the small particles 5. In FIG. 2, it is assumed that the small particle portion 50 includes a resin or the like (not shown). When the small particle part 50 contains resin, the small particle 5 becomes easy to adhere to the side part 15.

Here, the side 15 on the upper surface of the light emitting element 10 refers to the four sides (a, b, c, d) of the upper surface A of the light emitting element 10 and the vicinity thereof, as shown in FIG. That is, a connection portion between the upper surface A of the light emitting element 10 and four side surfaces (for example, the side surface B) of the light emitting element 10 and its vicinity, and a side portion of the light emitting element 10 and its vicinity (side Part). The range of the side portion is not particularly defined. For example, the phosphor layer 40 is not formed at or near the four sides (a, b, c, d) of the upper surface A of the light emitting element 10 or others. The part which will be formed thinly compared with the part.
Specifically, for example, from one side (for example, side a) to the side (here, side c) facing the upper surface A or the side (here, side e) facing the side B (indicated by the arrow in the figure) Direction) means a range of about 0.1% to 10% of the length of each side and a range of about 0.1% to 10% of the length of the side around the corner of the light emitting element 10.

  As described in the above item of the background art, when the phosphor layer 40 is formed on the surface of the light emitting element 10 by the spray method, the thickness of the phosphor layer 40 is determined from the element shape of the side portion 15 on the upper surface of the light emitting element 10. Will become thinner. Or the site | part in which the fluorescent substance layer 40 is not formed in the side part 15 will arise. Therefore, when the small particle part 50 is not provided on the side part 15, light may escape from the side part 15 on the upper surface of the light emitting element 10. However, since the light emitting device 100 of the present invention includes the small particle portion 50 in the side portion 15 of the light emitting element 10, light leakage from the side portion 15 can be reduced. Therefore, the light emitting device 100 has a sufficiently excellent light distribution.

  Note that the above-described problem that the phosphor layer 40 is not formed or is formed thinner than other portions is particularly noticeable in the corner portion of the upper surface of the light emitting element 10. However, in the present invention, since the small particle part 50 can be formed even at this corner, light leakage from the corner can be reduced. The corner portion refers to the corner portions at the four corners of the upper surface of the light emitting element 10 and the vicinity thereof, and is included in the side portion 15.

  The small particles 5 constituting the small particle portion 50 are members made of light reflecting particles or light diffusing particles having a particle diameter smaller than that of the phosphor 4 of the phosphor layer 40. The light reflecting particles are members that reflect at least part of the light from the light emitting element 10. The light diffusing particles diffuse light, and are members that can reduce the directivity from the light emitting element 10 and increase the viewing angle.

Examples of the light reflecting particles include SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZrO ₂ , BaSO ₄ , and MgO. The light reflecting particles may be at least one of these.
Examples of the light diffusing particles include BaTiO ₃ , TiO ₂ , SiO ₂ , Al ₂ O ₃ , and AlN. What is necessary is just to use at least 1 type of these for a light-diffusion particle.

The particle size of the small particles 5 is not particularly defined as long as it is smaller than the particle size of the phosphor 4. As an example, it is 0.005 to 3 μm.
The reason why the particle size of the small particles 5 is smaller than the particle size of the phosphor 4 is the same as the particle size of the phosphor 4 or larger than the particle size of the phosphor 4. This is because it is difficult to adhere to the side portion 15 on the upper surface of the surface, and it becomes difficult to form the small particle portion 50.

  In the phosphor 4 and the small particles 5, the particle size here means not the average particle size but the size of each particle size. Moreover, the measuring method of a particle size can be measured by observation with an optical microscope or an electron microscope, a light scattering method, or the like.

The small particle part 50 should just be formed in the edge part 15 of the upper surface of the light emitting element 10, for example, the 2 layer structure in which the small particle part 50 was formed in the upper surface of the fluorescent substance layer 40 formed thinly, Examples thereof include a two-layer or multi-layer structure in which the phosphor layer 40 is formed on the upper surface of the particle part 50. Alternatively, it may be a one-layer structure in which the phosphor layer 40 is hardly or not formed and only the small particle part 50 is formed.
Further, the small particles 5 may have a form in which the portion of the upper surface side (sides a, b, c, d) of the light emitting element 10 is the darkest and becomes thinner as the distance from the side increases. In other words, the light emitting element 10 may be thinned from one side of the upper surface of the light emitting element 10 toward the opposite side of the upper surface or the side surface (the arrow direction in FIG. 1).
The light emitting element 10, the phosphor layer 40, and the small particle part 50 described above are preferably sealed with a sealing member such as a resin.

  According to the above-described light emitting device 100 of the present invention, when the light emitting device 100 is driven, the light traveling upward from the light emitting element 10 is extracted to the outside above the light emitting device 100. . Further, the light traveling downward or laterally is reflected / scattered by the surface of the substrate 1, the conductive members 2 a and 2 b, or the resist film, and is extracted outside the light emitting device 100. Further, light leakage from the side portion 15 on the upper surface of the light emitting element 10 can be reduced, and occurrence of color unevenness can be reduced.

≪Method for manufacturing light emitting device≫
Next, a method for manufacturing a light emitting device according to the present invention will be described with reference to FIGS.

<First manufacturing method>
The first manufacturing method of the light emitting device 100 according to the present invention includes a phosphor layer forming step and a small particle portion forming step, which are performed in this order. In addition, here, a substrate preparation step and a die bonding step are included in this order before the phosphor layer forming step.
Hereinafter, each step will be described. Note that details of each member of the light-emitting device are as described in the above-described light-emitting device, and thus description thereof will be omitted as appropriate.

<Board preparation process>
The substrate preparation step is a step of preparing a substrate (mounting substrate) 20 including the conductive members 2 a and 2 b, for example, a step of forming the conductive members 2 a and 2 b on the base material 1. The conductive members 2a and 2b may be formed by a conventionally known method. For example, the conductive members 2a and 2b are formed by plating, vapor deposition, sticking to the base material 1, or the like. In the case of sticking to the base material 1, the base material 1 and the conductive members 2a and 2b can be bonded with an adhesive such as a resin. The conductive members 2a and 2b may be formed by etching or the like after the material of the conductive members 2a and 2b is formed on one surface of the substrate 1.

<Die bonding process>
The die bonding process is a process of mounting the light emitting element 10 on the mounting substrate 20. In this die bonding process, the light emitting element 10 is mounted on the upper surfaces of the conductive members 2a and 2b.
The mounting method of the light emitting element 10 is not particularly limited, and may be performed by a commonly used method. For example, the light emitting element 10 and the conductive members 2a and 2b may be joined with solder such as Au—Sn or Sn—Ag—Cu, or an epoxy resin containing a conductive member.

  In the present embodiment, the n-side electrode connected to the semiconductor layer 11 and the conductive member 2a are connected via the bump 3a, and the p-side electrode connected to the semiconductor layer 12 via the bump 3b and 3b. And the conductive member 2b are mounted by flip chip connection. Specifically, the bumps 3a and 3b are bonded to the electrode pads of the light emitting element 10 and the conductive members 2a and 2b by ultrasonic bonding.

<Phosphor layer forming step>
The phosphor layer forming step is a step of forming the phosphor layer 40 including the phosphor 4 on the surface of the light emitting element 10.
The method for forming the phosphor layer 40 is not particularly limited, and for example, a spray method, an electrodeposition (electrodeposition) method, an electrostatic coating method, a centrifugal sedimentation method, or the like can be used. However, as a method of forming the phosphor layer 40, it is preferable to use a spray method. If the spray method is used, the phosphor layer 40 can be formed in a substantially uniform thickness around the light emitting element 10. In addition, since the small particle part 50 is provided about the side part 15 of the upper surface of the light emitting element 10, the light omission from the side part 15 of the upper surface of the light emitting element 10 which was a problem in the prior art can be reduced.

As the spray method, it is preferable to use a pulse spray method (hereinafter, referred to as a pulse spray method as appropriate). The pulse spray method is a technique for forming a uniform particle layer by intermittently discharging (pulse spraying) a resin in which particles such as phosphors 4 and small particles 5 are mixed by air pressure.
In the case of continuous application, which is a normal spray method, the amount of application increases and the material is likely to scatter, so it is necessary to increase the nozzle speed. On the other hand, since the pulse spray method is intermittent discharge, the amount of application per unit time is small, the nozzle can be moved slowly, and the application liquid can be easily applied to the side surface and the minimal space of the light emitting element 10.

  In addition, the pulse spray method is capable of (1) uniform film formation even if the target application surface is uneven, (2) high adhesion of the coating solution, and application to the side and side of the light emitting element. (3) Color tone correction (application while measuring the color tone) is possible, (4) Wide selection of materials regardless of the type of phosphor and small particles, (5) High light quality A coating film having excellent color tone stability can be formed (for example, the range of color variation of the manufactured light emitting device can be changed to the color tone MacAdam 2step (if within the MacAdam 3step, a light emitting device having substantially no color variation can be mass-produced). It is possible to suppress it).

Next, an outline of a pulse type spray device (pulse spray device) will be described with reference to FIG.
As shown in FIG. 3, the pulse spray device 30 mainly includes syringes 31 and 32 for storing the slurry SL, a pipe 33 for connecting the syringes 31 and 32, and a spray nozzle 34 for injecting the slurry SL. .

In the syringes 31 and 32, a slurry SL in which particles such as phosphors and small particles, a resin, and a solvent are mixed is stored. In addition, an air compressor (not shown) for sending air is connected to the syringes 31 and 32, whereby the compressed gases 31 b and 32 b are kept at a predetermined pressure inside the syringes 31 and 32. .
Further, inside the syringes 31 and 32, blankers 31a and 32a are provided between the slurry SL and the compressed gases 31b and 32b. Since the blankers 31a and 32a separate the slurry SL from the compressed gas 31b and 32b, the dissolution of the compressed gas 31b and 32b into the slurry SL can be reduced.
A pipe 33 as a liquid passage is connected to the spray nozzle 34. An air compressor (not shown) for sending air is connected to the spray nozzle 34. The angle of the spray nozzle 34 can be adjusted, and the spray nozzle 34 can be inclined with respect to the mounting table 70.

  When spraying, first, air is sent from the air compressor to the syringe 31 at a predetermined pressure with the discharge valve of the spray nozzle 34 closed. The slurry SL filled in the syringe 31 is pressurized by this air feeding, and is pumped toward the syringe 32 through the pipe 33 which is a flow path. Thereafter, similarly, when air is fed into the syringe 32 at a predetermined pressure, the slurry SL filled in the syringe 32 is pressurized and fed toward the syringe 31 via the pipe 33 serving as a flow path. By repeating this, the slurry SL is stirred while moving between the syringes 31 and 32. Thereby, sedimentation of particles having a large specific gravity can be suppressed, and the state in which the particles are dispersed in the slurry SL can be maintained.

  When applying the slurry SL, the discharge valve of the spray nozzle 34 is opened, and air is intermittently sent from the air compressor to the spray nozzle 34 at a predetermined pressure. When this air is being sent in, the slurry SL can be intermittently discharged by opening a valve provided between the air compressor and the spray nozzle 34. As a result, the slurry SL is intermittently ejected together with air from the tip of the spray nozzle 34 and sprayed onto the light emitting element 10 (symbol SL).

Hereinafter, a method for forming a phosphor layer using the pulse spray method will be described with reference to FIG.
First, a slurry (phosphor slurry) in which phosphors are mixed is prepared. As the phosphor slurry, a mixture of a phosphor, a resin, and a solvent can be used. For example, the phosphor slurry is a mixture of a phosphor, a silicone resin, and n-heptane. The mixing ratio of the phosphor slurry is preferably a mass ratio of phosphor: resin: solvent = 2-40: 5-20: 10-200.
With such a blending ratio, it is easier to spray, and the phosphor is more likely to adhere uniformly to the light emitting element. It should be noted that such a blending ratio can also be suitably applied to spray methods other than the pulse spray method.
Next, the phosphor slurry sufficiently stirred and mixed is put into the syringes 31 and 32 of the pulse spray device 30. Then, the phosphor slurry is moved between the syringes 31 and 32, stirred, and applied by pulse spray. At that time, the phosphor slurry is applied while moving the spray nozzle 34 so that the phosphor slurry can be applied as evenly as possible to the upper and side surfaces of the light emitting element 10.

<Small particle part forming step>
In the small particle portion forming step, a small particle portion 50 including light reflecting particles or light diffusing particles having a particle diameter smaller than that of the phosphor 4 is formed on the side portion 15 on the upper surface of the light emitting element 10 on which the phosphor layer 40 is formed. It is a process to do.
The method for forming the small particle part 50 is not particularly limited, and for example, a spray method, an electrodeposition (electrodeposition) method, an electrostatic coating method, a centrifugal sedimentation method, or the like can be used. However, as a method of forming the small particle portion 50, it is preferable to use a spray method. If the spray method is used, the small particle part 50 can be easily formed on the side part 15 on the upper surface of the light emitting element 10.

  Moreover, as a spray method, it is preferable to use a pulse spray method. Since the pulse spray method is as described above, the description is omitted here.

Hereinafter, with reference to FIG. 3, the formation method of the small particle part using the pulse spray method is demonstrated.
First, a slurry in which small particles are mixed (small particle slurry) is prepared. As the small particles, light reflecting particles or light diffusing particles mixed with a resin and a solvent can be used. For example, light reflecting particles or light diffusing particles, silicone resin and n-heptane are mixed. . The mixing ratio of the small particle slurry is preferably a mass ratio of light reflecting particles or light diffusing particles: resin: solvent = 2-40: 5-20: 10-200.
With such a mixing ratio, spraying is easier and small particles are more likely to adhere uniformly to the side of the upper surface of the light emitting element. It should be noted that such a blending ratio can also be suitably applied to spray methods other than the pulse spray method.
Next, the sufficiently mixed small particle slurry is put into the syringes 31 and 32 of the pulse spray device 30. Then, the small particle slurry is moved between the syringes 31 and 32, stirred, and applied by pulse spray. At that time, the small particle slurry is applied while moving the spray nozzle 34 so that the small particle slurry can be applied to the side portion 15 on the upper surface of the light emitting element 10 as uniformly as possible.

Specifically, the angle of the spray nozzle 34 is normally perpendicular to the mounting table 70 (with respect to the mounting substrate 20), but in this step, the small particles 5 are removed from the side 15 of the upper surface of the light emitting element 10. In order to spray only on the spray nozzle 34, the spray nozzle 34 is inclined. Further, by applying as close to the light emitting element 10 as possible, it is applied as little as possible except for the side 15 on the upper surface of the light emitting element 10.
In this way, by forming the small particle part 50 on the side part 15 on the upper surface of the light emitting element 10, the problem that light escapes from the side part 15 on the upper surface of the light emitting element 10 can be solved.

<Second production method>
The second manufacturing method of the light emitting device 100 according to the present invention includes a small particle portion forming step and a phosphor layer forming step, which are performed in this order. Here, the substrate preparation step and the die bonding step are included in this order before the small particle portion forming step.
Since the second manufacturing method is the same as the first manufacturing method except that the small particle portion forming step and the phosphor layer forming step are performed in this order, here, the small particle portion forming step, the phosphor layer, and the like. A formation process is demonstrated.

<Small particle part forming step>
The small particle portion forming step is a step of forming the small particle portion 50 including the light reflecting particles or the light diffusing particles on the side portion 15 on the upper surface of the light emitting element 10.
Since this step is the same as the small particle portion forming step in the first manufacturing method except that the small particle portion 50 is formed before the phosphor layer 40 is formed, the description thereof is omitted here.

<Phosphor layer forming step>
The phosphor layer forming step is a step of forming the phosphor layer 40 including the phosphor 4 having a larger particle diameter than the light reflecting particles or the light diffusing particles on the surface of the light emitting element 10 on which the small particle portion 50 is formed.
Since this step is the same as the phosphor layer forming step in the first manufacturing method except that the phosphor layer 40 is formed after the small particle portion 50 is formed, the description thereof is omitted here.

  In the second manufacturing method, since the light emitting device 100 forms the small particle part 50 before forming the phosphor layer 40, the light from the light emitting element 10 is blocked or blocked at the side part 15 on the upper surface of the light emitting element 10. Diffused. At the same time, in the light emitting device 100, the side 15 on the upper surface of the light emitting element 10 is rounded by the small particle portion 50, so that the phosphor layer 40 adhering to the small particle portion 50 is easily attached evenly. .

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, It can change in the range which does not deviate from the meaning of this invention.
That is, the light emitting device manufacturing method and the light emitting device embodiment described above exemplify the light emitting device manufacturing method and the light emitting device for embodying the technical idea of the present invention. It is not limited to the manufacturing method or form. Moreover, the member etc. which are shown by a claim are not specified as the member of embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention only to the extent that there is no specific description. It is just an example.

  For example, a metal member that improves the efficiency of light reflection in the conductive members 2a and 2b may be provided on the surfaces of the conductive members 2a and 2b. The material of the metal member is not particularly limited. For example, only silver, or an alloy of silver and a metal having high reflectivity such as copper, gold, rhodium, or a multilayer using these silver or each alloy. A film or the like can be used. As a method for providing the metal member, a plating method, a sputtering method, a vapor deposition method, a method for bonding a thin film, or the like can be used.

  Moreover, you may provide the resist film which protects the electrically-conductive members 2a and 2b on the surface of the base material 1 and / or the electrically-conductive members 2a and 2b. The resist film is preferably a reflective film that increases the light reflectance. As such a material, a white insulating material such as a silicone resin containing titanium oxide can be used. A printing method can be suitably used for forming the resist film.

  In addition, the light emitting device 100 may include an underfill (not shown) between the upper surface of the substrate 1 and the light emitting element 10. By providing the underfill, optical characteristics such as light extraction efficiency and heat dissipation of the light emitting device 100 are improved, and thermal expansion and mechanical stress between the light emitting element 10 and the substrate 1 can be reduced. Therefore, the reliability of the light emitting device 100 can be improved. The underfill material is, for example, a thermosetting resin such as a silicone resin or an epoxy resin.

  In addition, in the above-described embodiment, the light emitting device 100 is configured to include the base material 1, the conductive members 2a and 2b, and the bumps 3a and 3b, but the base material 1, the conductive members 2a and 2b, and the bumps 3a and 3b. A light emitting device that does not include the light emitting device may be used. That is, the phosphor layer and the small particle portion may be provided in the light emitting element without the base material 1, the conductive members 2a and 2b, and the bumps 3a and 3b. Further, the mounting board may be composed of only the conductive members 2a and 2b.

As for the method for manufacturing a light emitting device, in the small particle part forming step of the first manufacturing method, the side of the upper surface of the light emitting element is masked to be exposed, and the small particle part is formed on the exposed side. Also good.
Hereinafter, a method for forming small particle portions by spraying using a mask will be described with reference to FIGS.

  4A to 4C, a substrate E on which a plurality of light emitting elements 10 are mounted on a mounting substrate 20 (here, a phosphor layer is formed) (FIG. 4A )) And a light emitting element side portion blowing mask F (hereinafter, appropriately referred to as mask F) (FIG. 4B). The mask F is provided with a groove (opening) G according to the position of the side portion on the upper surface of the light emitting element 10. What is necessary is just to adjust the width | variety of the groove part G suitably according to the desired range which forms a small particle part. Then, the mask F is placed on the substrate E so that the groove portion G of the mask F is positioned on the side of the upper surface of the light emitting element 10 (in the drawing, the upper and lower sides of the upper surface of the light emitting element 10) (FIG. 4C). ).

  Then, as shown in FIG. 5, first, small particle slurry is applied by spraying from above the mask F onto the side of the upper surface of the light emitting element 10 exposed from the groove G at the left end of the mask F in the drawing. Thereby, the small particle part 50 is formed. Next, the spray nozzle 34 is moved to the right (in the direction of the arrow in the figure), and sprayed onto the side of the upper surface of the light emitting element 10 exposed from the second groove G from the left of the mask F in the drawing. This operation is sequentially performed to form small particle portions 50 on upper and lower sides (see FIG. 4) of the upper surfaces of all the light emitting elements 10. Further, the mask F is rotated by 90 ° to expose the left and right side portions (see FIG. 4) of the upper surface of the light emitting element 10 from the groove portion G of the mask F. Then, in the same manner as in the above operation, the small particle slurry is applied by spraying, and the small particle portions 50 are formed on the left and right sides of the upper surfaces of all the light emitting elements 10. By adopting such a method, the small particle part 50 can be easily formed only in a desired range of the side part of the upper surface of the light emitting element 10.

Further, in the small particle part forming step of the second manufacturing method, masking may be performed so that the side part on the upper surface of the light emitting element is exposed, and the small particle part may be formed on the exposed side part. The method for forming the small particle portion by spraying using this mask is the same as the method for forming the small particle portion by spraying using the mask F for the first manufacturing method described above. Omitted.
In addition, although the method using a spray was demonstrated above as a formation method of the small particle part using a mask, it is good also as a method using a mask in the method which does not use a spray.

  In addition, in the manufacturing method of a light-emitting device, when performing this invention, you may include processes other than an above-described process between each process, or before and behind. For example, other processes such as a substrate cleaning process for cleaning the substrate, an unnecessary object removing process for removing unnecessary substances such as dust, and a mounting position adjusting process for adjusting the mounting position of bumps and light emitting elements may be included. Good.

DESCRIPTION OF SYMBOLS 1 Base material 2a, 2b Conductive member 3a, 3b Bump 4 Phosphor 5 Small particle (light-reflective particle or light-diffusion particle)
DESCRIPTION OF SYMBOLS 10 Light emitting element 11,12 Semiconductor layer 13 Growth substrate 15 Side 20 Mounting substrate 30 Pulse type spray apparatus (pulse spray apparatus)
31, 32 Syringe 31a, 32a Blanker 31b, 32b Compressed gas 33 Piping 34 Spray nozzle 40 Phosphor layer 50 Small particle part 70 Mounting table 100 Light emitting device A Upper surface of light emitting element B Side surface of light emitting element a, b, c, d Side (side) of top surface of light emitting element
E Substrate F Light emitting element side blowing mask G Groove SL Slurry SP Spray

Claims (10)

A phosphor layer forming step of forming a phosphor layer containing a phosphor on the surface of the light emitting element;
A small particle portion forming step of forming a small particle portion including light reflecting particles or light diffusing particles having a particle diameter smaller than that of the phosphor on the side portion of the upper surface of the light emitting element on which the phosphor layer is formed. A method for manufacturing a light-emitting device. A small particle part forming step of forming a small particle part including light reflecting particles or light diffusing particles on the side of the upper surface of the light emitting element;
A phosphor layer forming step of forming a phosphor layer including a phosphor having a particle size larger than that of the light reflecting particle or the light diffusing particle on the surface of the light emitting element on which the small particle portion is formed, A method for manufacturing a light emitting device.   The method for manufacturing a light emitting device according to claim 1, wherein the phosphor layer forming step is a step of applying a slurry containing a phosphor by spraying.   4. The method for manufacturing a light emitting device according to claim 3, wherein the spray in the phosphor layer forming step is a pulse type spray.   5. The light emitting device according to claim 3, wherein the slurry containing the phosphor has a mass ratio of phosphor: resin: solvent = 2 to 40: 5 to 20:10 to 200. 6. Production method.   The light emitting device manufacturing method according to any one of claims 1 to 5, wherein the small particle portion forming step is a step of applying a slurry containing light reflecting particles or light diffusing particles by spraying. Method.   The method of manufacturing a light emitting device according to claim 6, wherein the spray in the small particle portion forming step is a pulse type spray.   The slurry containing the light reflecting particles or the light diffusing particles is, in mass ratio, light reflecting particles or light diffusing particles: resin: solvent = 2-40: 5-20: 10-200. Or the manufacturing method of the light-emitting device of Claim 7.   9. The method according to claim 1, wherein, in the small particle portion forming step, masking is performed so that the side portion of the upper surface of the light emitting element is exposed, and the small particle portion is formed on the exposed side portion. A method for manufacturing the light emitting device according to claim 1. A light emitting element;
A phosphor layer formed on the surface of the light emitting element;
And a small particle portion including light reflecting particles or light diffusing particles having a particle diameter smaller than that of the phosphor of the phosphor layer, which is formed on a side portion of the upper surface of the light emitting element.

Images