JP2023150244A - Manufacturing method of light-emitting device and light-emitting device - Google Patents

Abstract

The present invention provides a method for manufacturing a light emitting device and a light emitting device that can improve light extraction efficiency. A method for manufacturing a light emitting device includes a step of applying a first member 301 on a substrate 10 on which one or more light emitting elements 20 are arranged so as to surround the light emitting elements 20 at a distance; a step of applying a second member 302 on the first member 301 so as to surround the light emitting element 20 at a distance, the first member 301 and the second member 302 have light reflective properties and emit light. The light reflectance at the emission peak wavelength of the element 20 is different. [Selection diagram] Figure 4C

Description

The present disclosure relates to a method of manufacturing a light emitting device and a light emitting device.

2. Description of the Related Art Light-emitting devices are known in which a light-emitting element is placed on a substrate and sealed with a light-transmitting resin. For example, Patent Documents 1 and 2 describe light-emitting devices in which a light-reflecting dam material is provided in an annular shape to dam a resin that seals light-emitting elements and the like.

JP 2017-50445 Publication JP2019-21744A

An object of embodiments according to the present disclosure is to provide a method for manufacturing a light-emitting device and a light-emitting device that can improve light extraction efficiency.

A method for manufacturing a light emitting device disclosed in the embodiments includes a step of applying a first member onto a substrate on which one or more light emitting elements are arranged so as to surround the light emitting elements at a distance, applying a second member on the first member so as to surround the light emitting element at a distance, the first member and the second member having light reflectivity, The light reflectance at the emission peak wavelength is different.

Further, the light emitting device disclosed in the embodiment includes one or more light emitting elements, a substrate on which the light emitting elements are arranged, a first frame that surrounds the light emitting elements at a distance on the substrate, and a first frame that surrounds the light emitting elements at a distance on the substrate; a second frame that surrounds the light emitting element at a distance on the first frame, the first frame and the second frame have light reflectivity, and the light reflectance at the light emission peak wavelength of the light emitting element is different.

According to the embodiments of the present disclosure, the light extraction efficiency of the light emitting device can be increased.

FIG. 1 is a perspective view schematically illustrating a light emitting device according to an embodiment. FIG. 1 is a plan view schematically illustrating a light emitting device according to an embodiment. FIG. 2B is a schematic cross-sectional view taken along line IIB-IIB in FIG. 2A. 1 is a flowchart illustrating a method for manufacturing a light emitting device according to an embodiment. FIG. 2 is a plan view illustrating a state in which light emitting elements are arranged on a substrate in a method for manufacturing a light emitting device according to an embodiment. FIG. 3 is a plan view illustrating a state in which the first member is arranged in the method for manufacturing a light emitting device according to the embodiment. FIG. 7 is a plan view illustrating a state in which a second member is arranged in the method for manufacturing a light emitting device according to an embodiment. FIG. 2 is a plan view illustrating a state in which a sealing member is arranged in a method for manufacturing a light emitting device according to an embodiment. FIG. 2 is a cross-sectional view illustrating a state in which a first member is applied in a method for manufacturing a light emitting device according to an embodiment. FIG. 7 is a cross-sectional view illustrating a state in which a second member is applied in the method for manufacturing a light emitting device according to an embodiment. FIG. 7 is a cross-sectional view illustrating a state in which the first member is applied in a first modification of the method for manufacturing a light emitting device. FIG. 7 is a cross-sectional view illustrating a state in which a second member is applied in a first modification of the method for manufacturing a light emitting device. It is a flowchart which illustrates the 2nd modification of the manufacturing method of a light emitting device. FIG. 7 is a cross-sectional view illustrating a state in which the first member is applied in a second modification of the method for manufacturing a light emitting device. FIG. 7 is a cross-sectional view illustrating a state in which a third member is applied in a second modification of the method for manufacturing a light emitting device. FIG. 7 is a cross-sectional view illustrating a state in which a second member is applied in a second modification of the method for manufacturing a light emitting device. 1 is a plan view schematically showing a light emitting device according to an embodiment, and illustrating a case where a plurality of light emitting elements are provided.

Embodiments according to the present disclosure will be described below. However, the embodiments described below illustrate a light-emitting device and a method for manufacturing a light-emitting device for realizing the technical idea according to the present disclosure, and are not limited to the following. In addition, the dimensions, materials, shapes, relative positions, etc. of the components described in the embodiments are not intended to limit the scope of the present invention, unless specifically stated, and are merely illustrative. Not too much. Note that the sizes, positional relationships, etc. of members shown in each drawing may be exaggerated or simplified for clarity of explanation. Furthermore, in the embodiments, "covering" is not limited to the case of direct contact, but also includes the case of covering indirectly, for example, via another member.

A light emitting device 1 according to an embodiment will be described with reference to the drawings. FIG. 1 is a perspective view schematically illustrating a light emitting device 1. As shown in FIG. FIG. 2A is a plan view schematically illustrating the light emitting device 1. FIG. FIG. 2B is a schematic cross-sectional view taken along line IIB-IIB in FIG. 2A.

The light emitting device 1 is a COB (Chip On Board) type light emitting device in which a light emitting element 20 is directly disposed on a substrate 10 having an electrode terminal 13.
The light emitting device 1 includes one or more (one in FIG. 2A) light emitting elements 20, a substrate 10 on which the light emitting elements 20 are arranged, and a first frame 31 that surrounds the light emitting elements 20 at a distance on the substrate 10. and a second frame 32 that surrounds the light emitting element 20 at a distance on the first frame 31. The first frame 31 and the second frame 32 have light reflectivity, and have different light reflectances at the light emission peak wavelength of the light emitting element 20. As an example, in the light emitting device 1, a first frame 31 and a second frame 32 constitute a frame 30, and a sealing member 40 that covers the light emitting element 20 is provided inside the frame 30. Each configuration of the light emitting device 1 will be described below.

(substrate)
The substrate 10 serves as the base of the light emitting device 1 and is a member on which the light emitting elements 20 are arranged. The substrate 10 has an electrode terminal 13 connected to an external power source and a wiring 12 continuous from the electrode terminal 13 on the upper surface of a plate-shaped base material 11 .
As an example, the base material 11 is formed into a rectangular shape when viewed from above. This base material 11 may have a polygonal shape other than a rectangle or a circular shape. The base material 11 can be made of resin such as epoxy, glass epoxy, bismaleimide triazine, or polyimide, or an insulating material such as ceramics or glass.

Note that a light reflecting member may be disposed on the upper surface of the base material 11 in order to improve light reflectivity on the surface. The light reflecting member is preferably white, and preferably contains a white pigment such as titanium oxide or magnesium oxide in the base material. Examples of the base material of the light reflecting member include resin such as silicone or modified resin. Further, the light reflecting member may further contain particles of a light reflecting substance such as silicon oxide or aluminum oxide as a filler.

For example, the wiring 12 is formed in a semicircular shape continuously from the positive and negative electrode terminals 13 so as to surround a circular region in which the light emitting element 20 is arranged.
The electrode terminals 13 are arranged in a rectangular shape at opposite corners of the base material 11 so as to have a wider area than the wiring 12.
The wiring 12 is connected to the light emitting element 20 by a bonding wire 14. The light emitting element 20 is arranged on the substrate 10 by face-up mounting. On the other hand, it is also possible to arrange the light emitting element 20 on the substrate 10 by flip-chip mounting without using the bonding wire 14. In this case, the wiring 12 may be formed to match the position of the element electrode of the light emitting element 20.
The material of the wiring 12 and the electrode terminal 13 can be metals such as copper, iron, nickel, tungsten, chromium, aluminum, titanium, palladium, rhodium, silver, platinum, and gold, or alloys thereof. The wiring 12 and the electrode terminal 13 may be formed of a single layer or multiple layers of these materials, and may also be plated. The bonding wire 14 is a linear member made of, for example, gold, copper, silver, platinum, aluminum, or an alloy thereof.

(Light emitting element)
The light emitting element 20 is a semiconductor element that emits light when a current flows therethrough, and can be, for example, an LED chip. The light emitting element 20 includes at least a semiconductor stack.
The semiconductor stack includes, for example, a support substrate made of sapphire or gallium nitride, an n-type semiconductor layer and a p-type semiconductor layer disposed on the support substrate, and a light-emitting layer sandwiched therebetween. Note that the semiconductor stack may be one in which the supporting substrate is removed. In addition, the structure of the light emitting layer may be a structure with a single active layer such as a double heterostructure or a single quantum well structure (SQW), or a structure with a single active layer such as a multiple quantum well structure (MQW). A structure having a group of layers may be used. The light emitting layer is capable of emitting visible light or ultraviolet light. The light emitting layer is capable of emitting visible light ranging from blue to red. A semiconductor stack including such a light emitting layer can include, for example, In _x Al _y Ga _1-x-y N (0≦x, 0≦y, x+y≦1).

The semiconductor stacked body can include at least one light-emitting layer capable of emitting light of the above-mentioned color. For example, the semiconductor stack may have a structure that includes one or more light emitting layers between an n-type semiconductor layer and a p-type semiconductor layer, or a structure that includes an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer. It may be a structure in which the structures included in this order are repeated multiple times. When the semiconductor laminate includes a plurality of light-emitting layers, it may include light-emitting layers that emit light of different colors, or it may contain light-emitting layers that emit light of the same color. Note that the same emission color may mean a range that can be considered to be the same emission color in use, for example, a variation of several nanometers in the main wavelength. The combination of emitted light colors can be selected as appropriate, for example, blue light and blue light, green light and green light, red light and red light, ultraviolet light and ultraviolet light, blue light and green light, blue light and red light. , or green light and red light.
In addition to the light emitting element 20, a protection element 15 may be provided between the positive electrode and negative electrode wirings 12. The protection element 15 can be, for example, a Zener diode, a varistor, a resistor, or a capacitor.
The height from the top surface of the substrate 10 to the top surface of the light emitting element 20 is preferably 150 μm or more and 400 μm or less, particularly preferably 200 μm or more and 350 μm or less.

(Frame)
The frame body 30 is a member that serves as a frame that partitions a light emitting area in the light emitting device 1. It is preferable that the frame 30 has light reflectivity. The frame 30 surrounds the light emitting element 20 on the substrate 10 at a distance. The frame 30 has a width wider than the wiring 12, is formed in a circular shape so as to cover the wiring 12, and surrounds a region where the light emitting element 20 is arranged. The frame 30 may have a polygonal shape such as an ellipse, a square, a pentagon, or a hexagon depending on the area where the light emitting element 20 is arranged.
It is preferable that the frame 30 widens toward the substrate 10 in a cross-sectional view. The frame 30 is formed so that its height from the top surface of the substrate 10 is higher than at least the top surface of the light emitting element 20 . The height of the frame 30 from the top surface of the substrate 10 is preferably 300 μm or more and 1200 μm or less, particularly preferably 400 μm or more and 1000 μm or less.
The frame body 30 includes a first frame 31 that covers the wiring 12 and a second frame 32 provided on the first frame 31.

(1st slot)
The first frame 31 is a member located on the substrate 10 side of the frame body 30. The first frame 31 forms a widened portion of the frame body 30. It is preferable that the first frame 31 has an inclined surface 35 that forms an angle of 10 degrees or more and 45 degrees or less with the upper surface of the substrate 10 and descends toward the light emitting element 20, particularly preferably 15 degrees or more and 40 degrees or less. The width of the first frame 31 in plan view is preferably 700 μm or more and 1450 μm or less, particularly preferably 1000 μm or more and 1300 μm or less. This first frame 31 has light reflectivity. The first frame 31 differs from the second frame 32 in light reflectance at the light emission peak wavelength of the light emitting element 20. Here, the expression "different light reflectances" means that the light reflectances of the light emitting elements 20 at the emission peak wavelength differ by at least 3%, preferably by 5% or more, and more preferably by 8% or more.
The light reflectance of the first frame 31 at the light emission peak wavelength of the light emitting element 20 is 90% or more, preferably 95% or more, and more preferably 97% or more. On the other hand, the light reflectance of the second frame 32 at the emission peak wavelength of the light emitting element 20 is different from the first frame 31 by at least 3%, and is 90% or more, preferably 95% or more, and more preferably 97% or more. It is.

(Second frame)
The second frame 32 is a member located on the upper side of the frame body 30. The upper end of the second frame 32 forms the upper end of the frame 30. The width of the second frame 32 in plan view is narrower than the first frame 31, preferably 400 μm or more and 1400 μm or less, particularly preferably 600 μm or more and 1200 μm or less. The shape of the second frame 32 in a cross-sectional view is an ellipse or a circle. The lower surface side of the second frame 32 may be in contact with the substrate 10, or a portion of the lower surface may be flat.

The material of the first frame 31 and the second frame 32 can be a light-reflective and insulating resin or ceramics. The first frame 31 and the second frame 32 may be made of the same base material. Further, when the first frame 31 and the second frame 32 are made of resin as a base material, particles of a light reflective substance can be dispersed in the resin as a base material as a filler. Further, when the base material is made of ceramics, it can be made of a light-reflecting ceramic material, and a different type of light-reflecting material may be contained therein.
The first frame 31 and the second frame 32 may both be made of resin, both of which may be made of ceramic, or one of which may be made of resin and the other made of ceramic. When both are made of resin or ceramics, it is preferable that the base materials are the same from the viewpoint of adhesion and coefficient of thermal expansion.
The base material of the resin can be, for example, dimethyl silicone resin, phenyl silicone resin, epoxy resin, etc., and preferably dimethyl silicone resin has high heat resistance.
The ceramic base material can be boron nitride, aluminum oxide, aluminum nitride, silicon nitride, silicon dioxide, zirconium oxide, or the like.

As the light reflective material, titanium oxide, silicon dioxide, zirconium oxide, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, mullite, etc. can be used. When the emission color of the light emitting element 20 is ultraviolet light, fillers other than titanium oxide, such as potassium titanate, zirconium oxide, yttrium oxide, etc., can be used.
The light reflectance of ceramics can be adjusted by the type of light-reflective substance, and the light reflectance of resin can be adjusted by the type and content of filler. Note that when the filler content is increased, the viscosity of the resin tends to increase.

The first frame 31 and the second frame 32 have different light reflectances at the emission peak wavelength of the light emitting element 20. That is, the light reflectance of the first frame 31 at the light emission peak wavelength of the light emitting element 20 can be made larger or smaller than the light reflectance of the second frame 32.
By increasing the light reflectance of the first frame 31, it is possible to suppress deterioration of the first frame 31 and the second frame 32 due to heat and light. From this point of view, the light reflectance of the first frame 31 is preferably greater than the light reflectance of the second frame 32.
On the other hand, from the viewpoint of forming the inclined surface 35, it may be easier to adjust the shape if the light reflectance is not increased. In such a case, the light reflectance of the first frame 31 can be reduced and the light reflectance of the second frame 32 can be increased.

In the light emitting device 1, a frame body 30 can be configured by a first frame 31 and a second frame 32. The frame 30 is required to have high light reflectivity while ensuring a predetermined width and height from the substrate 10. However, in forming the frame 30, there may be a trade-off between light reflectivity and ease of adjusting the shape. In the light emitting device 1, the first frame 31 and the second frame 32 having different light reflectances mutually complement the light reflectivity and the ease of adjusting the shape of the frame body 30, and the shape and light reflection of the frame body 30 are adjusted. It is possible to achieve both performance and increase light extraction efficiency.

In the light emitting device 1, it is preferable that the first frame 31 has an inclined surface 35 that forms an angle of 10 degrees or more and 45 degrees or less with the upper surface of the substrate 10 and descends toward the light emitting element 20.
Thereby, the light-emitting device 1 can reflect the light from the side surface of the light-emitting element 20 upward, and can more efficiently extract light from the light-emitting surface.

In the light emitting device 1, it is preferable that the first frame 31 and the second frame 32 are made of resin having the same base material. Thereby, the light emitting device 1 can improve the adhesion between the first frame 31 and the second frame 32, and increase the reliability of the frame body 30. Here, even if the first frame 31 and the second frame 32 are made of the same base material, the first frame 31 and the second frame 32 have different light reflectances. If the second frame 32 is applied before the first frame 31 is cured or solidified, an interface between the first frame 31 and the second frame 32 may not occur.

In the light emitting device 1, it is preferable that the first frame 31 is made of ceramics and the second frame 32 is made of resin. Thereby, in the light-emitting device 1, ceramics with high light reflectance and heat resistance can be disposed at a position close to the light-emitting element 20, thereby increasing light extraction efficiency and improving reliability. By making the resin of the second frame 32 contain more filler than the ceramic of the first frame 31, the height of the frame 30 can be ensured by increasing the light reflectance and increasing the viscosity. Note that even if a ceramic void occurs in the first frame 31, the resin of the second frame 32 can fill the void, so that cracks and chips due to the void can be reduced.

In the light emitting device 1, it is preferable that the first frame 31 is made of resin and the second frame 32 is made of ceramics. As a result, the light emitting device 1 can improve light extraction efficiency by forming the first frame 31 in a desired shape using resin whose shape can be easily adjusted, and by forming the second frame 32 from ceramics with high light reflectance. can be achieved. Further, when a ceramic material from which alkaline components are easily eluted is used for the second frame 32, corrosion of the wiring 12 can be suppressed because the second frame 32 does not come into direct contact with the wiring 12. However, it is preferable that the resin of the first frame 31 is a member that does not transmit the alkaline component or a member that hardly transmits the alkaline component.

The light reflectance of the first frame 31 at the light emission peak wavelength of the light emitting element 20 is preferably larger than the light reflectance of the second frame 32. Thereby, the light emitting device 1 increases the light reflectance of the first frame 31 located below near the light emitting element 20, and effectively prevents deterioration of the first frame 31 and the second frame 32 due to heat and light. Can be suppressed.

(Sealing member)
The sealing member 40 is a member that forms a light emitting region of the light emitting device 1. The upper surface of the sealing member 40 forms the light emitting surface of the light emitting device 1. Further, the sealing member 40 is a member that covers and protects the light emitting element 20 and the bonding wire 14. The sealing member 40 is filled inside the frame 30 . The height of the peripheral edge of the sealing member 40 can be less than or equal to the height of the upper end of the frame 30, and here is the height of the upper end of the frame 30. It is preferable that the sealing member 40 has a central portion higher in height than a peripheral portion and has a convex shape in cross-sectional view. Thereby, the light emitting device 1 can increase the brightness when viewed from above.
It is preferable that the sealing member 40 has insulating properties and translucency, and has excellent weather resistance and light resistance. The material of the sealing member 40 can be, for example, a resin whose base material is silicone, epoxy, phenol, polycarbonate, acrylic, or the like. The sealing member 40 may contain a wavelength converting substance or a light reflective substance as a filler.

The wavelength conversion material absorbs at least a portion of the primary light emitted by the light emitting element 20 and emits secondary light having a wavelength different from that of the primary light. For example, white light can be obtained by mixing the primary light emitted by the light emitting element 20 and the secondary light emitted by the wavelength conversion material. It is preferable that the wavelength conversion substance is unevenly distributed near the light emitting element 20, thereby increasing the efficiency of wavelength conversion.
The light-reflecting material can diffuse the light emitted by the light-emitting element 20 or the wavelength conversion material, thereby making the brightness uniform on the light-emitting surface. Preferably, the light reflective substance is dispersed in the sealing member 40.
The sealing member 40 may be formed by laminating materials that differ in the presence or absence or type of wavelength conversion substances and light-reflecting substances they contain.

[Method for manufacturing light emitting device]
Next, a method for manufacturing the light emitting device according to the embodiment will be described with reference to FIGS. 3 to 5B. FIG. 3 is a flowchart illustrating a method for manufacturing a light emitting device. FIG. 4A is a plan view schematically illustrating a state in which the light emitting element 20 is placed on the substrate 10. FIG. 4B is a plan view schematically illustrating a state in which the first member 301 is arranged. FIG. 4C is a plan view schematically illustrating a state in which the second member 302 is placed. FIG. 4D is a plan view schematically illustrating a state in which the sealing member 40 is arranged. FIG. 5A is a cross-sectional view schematically illustrating a state in which the first member 301 is applied. FIG. 5B is a cross-sectional view schematically illustrating a state in which the second member 302 is applied.

The method for manufacturing a light emitting device includes a step S21 of applying a first member 301 on a substrate 10 on which one or more light emitting elements 20 are arranged so as to surround the light emitting elements 20 at a distance, The first member 301 and the second member 302 have light reflectivity, and the second member 302 is coated on the first member 301 so as to surround the light emitting element 20 at a distance. The light reflectance at the emission peak wavelength is different.
Note that the process S21 of applying the first member 301 and the process S22 of applying the second member 302 are collectively referred to as the application process S20. Further, the first member 301 and the second member 302 are combined to form a frame member 300.
The method for manufacturing a light emitting device includes a preparation step S10, which is performed before the coating step S20 and prepares the substrate 10 on which the light emitting element 20 is disposed, and a step S10, which is performed between or after the coating step S20, and which hardens the frame member 300. The method further includes a curing step S30 in which the frame body 30 is formed by the curing process S30, and a sealing process S40 in which a sealing member 40 is formed inside the frame body 30, which is performed after the curing process S30. Each step of the method for manufacturing a light emitting device will be described below. Here, although it is described as curing or a hardening process, it may also be a solidification or solidification process. Also, hardening is sometimes referred to as solidifying, and conversely, solidifying is sometimes referred to as curing, but the meaning is to solidify a liquid.

(Preparation process)
The preparation step S10 is a step of preparing the substrate 10 on which the light emitting element 20 is arranged. First, the positive and negative electrode wirings 12 and the electrode terminals 13 are formed on the upper surface of the base material 11, for example, by etching. The wiring 12 is formed so as to surround a region where the light emitting element 20 is arranged. A light reflecting member may be provided in this area before placing the light emitting element 20. The light emitting element 20 is preferably placed at the center of this area.
The light emitting element 20 is adhered to the base material 11 or the light reflecting member using an adhesive member. The light emitting element 20 is arranged so that the surface having the pair of element electrodes is the upper surface, and the pair of element electrodes are connected to the wiring 12 by a bonding wire 14. Further, a protection element 15 is provided between the positive electrode and negative electrode wirings 12.

(Coating process)
The coating step S20 is a step of coating the first member 301 and the second member 302. The coating step S20 includes a step S21 of coating the first member 301 on the substrate 10 so as to surround the light emitting element 20 at a distance, and a step S21 of applying the first member 301 on the coated first member 301 so as to surround the light emitting element 20 at a distance. A step S22 of applying the second member 302 to the substrate is performed. The coating step S20 can be performed by applying the material of the frame member 300 that has fluidity before hardening or solidification using a dispenser nozzle.
The step S21 of applying the first member 301 is performed by advancing the first nozzle 81 while discharging the first member material 301A from the first nozzle 81 of the dispenser. The first nozzle 81 can move clockwise or counterclockwise around the area where the light emitting element 20 is arranged. Here, it is made to circulate along the wiring 12 in a counterclockwise direction D1. Note that FIG. 5A illustrates the state after the first nozzle 81 has passed.

The step S22 of applying the second member 302 is performed by advancing the second nozzle 82 while discharging the second member material 302A from the second nozzle 82 of the dispenser. Similarly to the first nozzle 81, the second nozzle 82 can move clockwise or counterclockwise around the area where the light emitting element 20 is arranged. Here, it is made to revolve in a counterclockwise direction D1 along the first member 301. FIG. 5B illustrates the state after the second nozzle 82 has passed. Note that the first nozzle 81 and the second nozzle 82 may be described as the nozzle 80.

The first member 301 is applied so that it has a wide bottom shape after the second member 302 is placed. The shape of the first member 301 can be adjusted depending on the viscosity. Here, the viscosity is adjusted so that an inclined surface 350 forming an angle of 10 degrees or more and 45 degrees or less with the upper surface of the substrate 10 is formed on the light emitting element 20 side. Note that when the viscosity is lowered, the slope of the inclined surface 350 tends to become gentler. Further, it is preferable that the wettability of the first member 301 with respect to the base material 11 and the wiring 12 is set within a predetermined range so that the first member 301 does not spread laterally more than necessary. In other words, even if the first member 301 does not have a wide bottom shape when applied onto the substrate 10, by applying the second member 302 onto the first member 301, the first member 301 spreads laterally. , the bottom may be widened. By doing so, it is possible to suppress the spread of the first member 301 in the lateral direction and to increase the height of the frame member 300. For example, the angle of the inclined surface 350A with respect to the substrate 10 when applying the first member 301 may be greater than or equal to 70 degrees and less than or equal to 150 degrees.

Further, the width of the first member 301 after the second member 302 is arranged is preferably 700 μm or more and 1450 μm or less, particularly preferably 1000 μm or more and 1300 μm or less. The height of the first member 301 before applying the second member 302 and before processing such as pressing is preferably 200 μm or more and 1000 μm or less, particularly preferably 300 μm or more and 800 μm or less. The inner diameter of the first nozzle 81 is preferably 100 μm or more and 600 μm or less, particularly preferably 200 μm or more and 450 μm or less. The first member 301 is applied by rotating the first nozzle 81 one or more times.

On the other hand, the second member 302 is coated with priority given to increasing the height. The shape of the second member 302 can also be adjusted depending on the viscosity. The viscosity of the second member 302 is preferably higher than the viscosity of the first member 301.
The height of the upper end of the second member 302 is preferably at least twice the height of the upper surface of the light emitting element 20 with respect to the upper surface of the substrate 10. The second member 302 can be applied multiple times by rotating the second nozzle 82 multiple times.
During the revolution of the nozzle 80, it is preferable to stop discharging the material so that the end point of the revolution continues without overlapping the starting point. Thereby, changes in the height of the frame member 300 can be suppressed.

The frame member 300 is made of a light-reflecting material. The first member 301 and the second member 302 in the frame member 300 have different light reflectances at the light emission peak wavelength of the light emitting element 20. It is preferable that the frame member 300 has a high light reflectance.
The material of the frame member 300 can be resin or ceramics. In the case of resin, it can be a material that has fluidity depending on the base material before hardening. In the case of ceramics, ceramic particles can be dispersed in a dispersant such as water to form a material that has fluidity before solidification.

Ceramics can have higher light reflectance than resin. However, ceramics before solidification has a higher viscosity than resin, and when a light-reflecting substance is added, the viscosity becomes even higher, which may make it difficult to form the frame member 300 by coating. Furthermore, the viscosity may suddenly increase due to the addition of a light-reflecting substance, making it difficult to adjust the viscosity. Note that ceramics have the advantage of having higher heat resistance than resins.
The viscosity of resin can be adjusted over a wide range, and the viscosity can be changed little by little, making it easy to adjust the viscosity. The viscosity of the resin can be adjusted, for example, by adjusting the filler content, and as the filler content increases, the viscosity tends to increase. The light reflectance of the resin can be increased by increasing the content of the light-reflective filler, and even when the content of the filler is increased, the viscosity should be within a range suitable for forming the frame member 300 by coating. I can do it.

In the frame member 300, both the first member 301 and the second member 302 can be made of resin, and the base material can be made of the same resin. Further, both the first member 301 and the second member 302 can be made of ceramics, and by making both of them ceramics, the light reflectance can be increased.
Further, in the frame member 300, the first member 301 can be made of ceramics and the second member 302 can be made of resin, and the first member 301 can be made of resin and the second member 302 can be made of ceramics.

The second member 302 is preferably applied so that the center of the second member 302 in the width direction is further away from the light emitting element 20 than the center of the first member 301 in the width direction. For example, it is possible to set a target line C2 outside the widthwise center line C1 of the applied first member 301, and apply the coating so that the center of the second nozzle 82 passes through the target line C2.
The width of the second member 302 is preferably 400 μm or more and 1400 μm or less, particularly preferably 600 μm or more and 1200 μm or less. The height of the second member 302 from the top surface of the substrate 10 is preferably 300 μm or more and 1200 μm or less, particularly preferably 400 μm or more and 1000 μm or less. The inner diameter of the second nozzle 82 is preferably 100 μm or more and 600 μm or less, particularly preferably 200 μm or more and 450 μm or less.

Further, the width of the frame member 300 can also be adjusted by the amount of discharge per unit time from the nozzle 80 and the speed of movement of the nozzle 80. By increasing the discharge amount per unit time or slowing down the progress of the nozzle 80, the frame member 300 can be coated with a wide width. When changing the traveling direction of the nozzle 80 so as to form a corner in a plan view, for example, by reducing the discharge amount near the corner without changing the traveling speed, the change in the width of the frame member 300 can be suppressed. It can be suppressed.

(Curing process)
The curing step S30 is a step of curing the frame member 300 to form the frame body 30. Here, "hardening using resin" will be explained, but "hardening using ceramics" may also be used.
In the curing step S30, a first curing step S31 and a second curing step S32 are performed. The first curing step S31 is a step performed before the step S22 of applying the second member 302. The second curing step S32 is a step performed after the step S22 of applying the second member 302.
The first curing step S31 can be omitted. That is, the second member 302 may be applied after the first member 301 is cured in the first curing step S31, or the second member 302 may be applied on the first member 301 before curing, omitting the first curing step S31. It's okay. If the first curing step S31 is omitted, both the first member 301 and the second member 302 can be cured by the second curing step S32. However, when the first member 301 is made of ceramics, it is preferable to perform the first curing step S31 because the volume may decrease significantly due to solidification.

The resin is cured by a predetermined method such as heating or irradiation with light such as ultraviolet rays. Preferably, the ceramic is solidified using a pressure oven. By solidifying while applying pressure, it is possible to reduce voids inside the ceramic and improve light reflectance.

(Sealing process)
The sealing step S40 is a step of forming the sealing member 40 inside the frame 30. The sealing member 40 is formed by arranging and curing the uncured material of the sealing member 40. The material of the sealing member 40 can be, for example, a thermosetting resin, and may contain a wavelength converting substance or a light reflective substance as a filler.
The sealing member 40 is formed inside surrounded by the frame 30 so as to cover at least the upper surface of the substrate 10, the light emitting element 20, the bonding wire 14, and the first frame 31. It is preferable that the sealing member 40 has a central portion higher in height than a peripheral portion, and has a convex shape in cross-sectional view.

The method for manufacturing a light emitting device is to combine a first member 301 and a second member 302 with different light reflectances to achieve both the light reflectivity of the frame member 300 and the adjustment of the shape by coating, thereby increasing the light extraction efficiency. It is possible to manufacture a light emitting device.

In the method for manufacturing a light emitting device, it is preferable that the viscosity of the second member 302 be higher than the viscosity of the first member 301. Thereby, in the method for manufacturing a light emitting device, the first member 301 can be applied in a shape with a wide base, and the height of the frame member 300 can be secured by the second member 302.

In the method for manufacturing a light emitting device, it is preferable that the first member 301 and the second member 302 are made of resin having the same base material. Thereby, in the method for manufacturing a light emitting device, it is easy to adjust the viscosity of the first member 301 and the second member 302 and apply each of them in a desired shape. Further, by using the same base material, the adhesion between the first member 301 and the second member 302 can be improved.

In the method for manufacturing a light emitting device, it is preferable that the first member 301 is made of ceramics and the second member 302 is made of resin. Thereby, the light reflectance of the first member 301 can be increased, and the second member 302 can be easily coated to increase its viscosity and height. By increasing the heat resistance of the first member 301 located near the light emitting element 20, the reliability of the light emitting device can be improved. The viscosity of the second member 302 can be increased by increasing the content of the light-reflective filler, and the light reflectance can also be increased. Note that by solidifying ceramics, the filling properties of the light-reflecting substance can be improved, and the light reflectance can be further increased.

In the method for manufacturing a light emitting device, it is preferable that the first member 301 is made of resin and the second member 302 is made of ceramics. Thereby, the first member 301 can be easily coated into a desired shape by adjusting the viscosity. Further, the second member 302 can increase the light reflectance.
The method for manufacturing a light emitting device combines the advantages of resin in adjusting the shape and the advantages of ceramics in light reflectance to form a frame 30 with a desired shape and high light reflectance, thereby increasing light extraction efficiency. It is possible to manufacture a light emitting device with improved performance.

In the step S22 of applying the second member 302 in the method for manufacturing a light emitting device, it is preferable to apply the second member 302 in a plurality of layers.
Thereby, the width of the second member 302 can be suppressed from increasing, and the second member 302 can be applied to a desired height.

In the step S22 of applying the second member 302 in the method for manufacturing a light emitting device, it is preferable that the center of the second member 302 in the width direction is located further away from the light emitting element 20 than the center of the first member 301 in the width direction. .
Thereby, reduction in the inner diameter of the first member 301 due to application of the second member 302 can be suppressed. Further, the inner peripheral side surface of the frame member 300 can be smoothed.

(Variation of manufacturing method)
Next, a first modification of the method for manufacturing the light emitting device according to the embodiment will be described. The first modification includes a step S21 of applying a first member 301 on a substrate 10 on which one or more light emitting elements 20 are arranged so as to surround the light emitting elements 20 at a distance, and The step S22 of applying the second member 302 on the member 301 so as to surround the light emitting element 20 at a distance, and the step S21 of applying the first member 301 includes discharging the first member 301 from a nozzle. The first member 301 is applied so as to have a height equal to or higher than the position of the discharge port of the nozzle in the direction perpendicular to the substrate 10 .

The first modification differs from the manufacturing method according to the embodiment in the position of the first nozzle 81 in step S21 of applying the first member 301. Further, in the step S22 of applying the second member 302, the first nozzle 81 may be used. Other points are common to the manufacturing method according to the embodiment.
FIG. 6A is a cross-sectional view schematically illustrating a state in which the first member 301 is applied. FIG. 6B is a cross-sectional view schematically illustrating a state in which the second member 302 is applied.

In step S21 of applying the first member 301 in the first modification, the first nozzle 81 is brought close to the substrate 10 and the material 301A is applied so as to be pressed against the substrate 10. In order to press the material 301A onto the substrate 10, in addition to moving the first nozzle 81 closer to the substrate 10, increase the amount of material 301A discharged per unit time and slow down the progress of the first nozzle 81. Can be done. The first member 301 is applied so as to spread over the substrate 10. The upper end of the first member 301 is raised to a height higher than the discharge port 81A of the first nozzle 81. It is preferable that the first member 301 is not in contact with the side surface 81B of the first nozzle 81.
The materials of the first member 301 and the second member 302 are the same as those in the manufacturing method according to the embodiment. However, in the first modification, the viscosity of the first member 301 and the second member 302 may be the same or different. The first member 301 can be applied in a shape with a wide base without lowering the viscosity. Further, the light reflectances of the first member 301 and the second member 302 at the emission peak wavelength of the light emitting element 20 may be the same or different.

Further, the material of the base material of the first member 301 and the second member 302 is the same, and in the step S22 of applying the second member 302, the first nozzle 81 used in the step S21 of applying the first member 301 is replaced with the first nozzle 81 used in the step S21 of applying the first member 301. The second nozzle 82 may be moved away from the member 301 to a height at which the second nozzle 82 is intended to dispense the second member 302, and the first nozzle 81 may be used to apply the second member 302.
Furthermore, the material 301A of the first member 301 may be used as is as the material 302A of the second member 302.

In the first modification of the method for manufacturing a light emitting device, even if the first member 301 has a higher viscosity than in the case where the shape is adjusted by viscosity, it can be applied in a shape with a wide base. For example, the viscosity of the first member 301 and the second member 302 may be approximately the same, which allows the range of material selection to be expanded, and it is possible to manufacture a light emitting device with increased light extraction efficiency.
Furthermore, in the first modification, the same nozzle can be used in the step S21 of applying the first member 301 and the step S22 of applying the second member 302, thereby simplifying the manufacturing process.

Next, a second modification of the method for manufacturing the light emitting device according to the embodiment will be described. In the second modification, an inclined surface 350A that is continuous with the inner peripheral side surface of the first member 301 and forms an angle of 10 degrees or more and 45 degrees or less with the upper surface of the substrate 10 and descends toward the light emitting element 20 is formed. The method further includes a step S23 of applying a third member 303 to the third member 303, and the third member 303 has light reflectivity and has a different light reflectance from the second member 302 at the light emission peak wavelength of the light emitting element 20.

In the second modification, as compared to the method for manufacturing a light emitting device according to the embodiment, the coating step S20 further includes a step S23 of coating the third member 303. The curing step S30 further includes a third curing step S33. Other points are common to the manufacturing method according to the embodiment. Note that the first member 301, the second member 302, and the third member 303 are collectively referred to as the frame member 300.
FIG. 7 is a flowchart illustrating a second modification of the method for manufacturing a light emitting device. FIG. 8A is a cross-sectional view schematically illustrating a state in which the first member 301 is applied. FIG. 8B is a cross-sectional view schematically illustrating a state in which the third member 303 is applied. FIG. 8C is a cross-sectional view schematically illustrating a state in which the second member 302 is applied.

The coating step S20 of the second modification is performed in the following order: step S21 of applying the first member 301, step S23 of applying the third member 303, and step S22 of applying the second member 302. The application of the first member 301 and the second member 302 is performed in the same manner as in the manufacturing method according to the embodiment. However, the first member 301 does not have to have a wide bottom shape, and may have a recess 340 between it and the upper surface of the substrate 10. The cross-sectional shape of the first member 301 may be, for example, circular or elliptical.
The third member 303 is applied continuously to the inner peripheral side surface of the first member 301 so as to form an inclined surface 350A. The inclined surface 350A is preferably formed to form an angle of 10 degrees or more and 45 degrees or less with the upper surface of the substrate 10 so as to descend toward the light emitting element 20, and particularly preferably 15 degrees or more and 40 degrees or less.

The application of the third member 303 is performed by spraying the material of the third member 303 from the jet dispenser 90 toward the side surface of the inner circumference of the first member 301 closer to the substrate 10 . Here, the jet dispenser 90 is moved counterclockwise along the first member 301. Note that FIG. 8B illustrates the state after the jet dispenser 90 has passed.
After applying the third member 303, the second member 302 is applied. After the second member 302 is applied, the combined first member 301 and third member 303 have a trapezoidal cross-sectional shape.

The materials of the first member 301 and the second member 302 are the same as those in the manufacturing method according to the embodiment. The first member 301 and the second member 302 have different light reflectances at the emission peak wavelength of the light emitting element 20. The viscosity of the first member 301 and the second member 302 may be the same or different.
The material of the third member 303 can be resin or ceramics, similarly to the first member 301 and the second member 302. It is preferable that the third member 303 has a lower viscosity than the first member 301. Since the third member 303 has a low viscosity, it is easy to apply it to form the inclined surface 350A. The third member 303 has light reflectivity, and has a different light reflectance from the second member 302 at the emission peak wavelength of the light emitting element 20 .

The curing process S30 of the second modification includes a first curing process S31, a second curing process S32, and a third curing process S33. The first curing step S31 is a step performed before the step S23 of applying the third member 303. The second curing step S32 is a step performed before the step S22 of applying the second member 302. The third curing step S33 is a step performed after the step S22 of applying the second member 302.
The first curing step S31 can be omitted. That is, the third member 303 may be applied after curing the first member 301 in the first curing step S31, or the first curing step S31 may be omitted and the third member 303 may be coated on the inner circumference of the first member 301 before curing. May be applied to the sides.

Furthermore, the first curing step S31 and the second curing step S32 may be omitted. That is, the second member 302 may be applied after the first member 301 and the third member 303 are cured, or may be applied on the first member 301 before being cured. When the first curing step S31 and the second curing step S32 are omitted, the first member 301, the second member 302, and the third member 303 can be cured in the third curing step S33. However, for example, when the first member 301 is made of ceramics, it is preferable to perform the first curing step S31 or the second curing step S32.

In the second modification of the method for manufacturing a light emitting device, even when the first member 301 does not have a wide base, the shape can be modified so that the inner peripheral side surface has the inclined surface 350A. For example, even if the inner peripheral side surface of the first member 301 has a recess 340 between it and the upper surface of the substrate 10, the third member 303 can be applied to form the inclined surface 350A. Therefore, even a material with high viscosity can be used for the first member 301. In addition, in the second modification, by combining a second member 302 and a third member 303 with different light reflectances, the range of material selection for the frame member 300 is expanded to achieve both shape and light reflectance, A light emitting device with improved light extraction efficiency can be manufactured.

Next, a light emitting device 1B including a plurality of light emitting elements 20 will be described. As shown in FIG. 9, the light emitting device 1B includes, for example, ten light emitting elements 20. The ten light emitting elements 20 are connected in series by bonding wires 14. It is preferable that the light emitting elements 20 are arranged so that the distances from each other are approximately the same.
Except for the number of light emitting elements 20, the configuration and manufacturing method of the light emitting device 1B are the same as the configuration and manufacturing method of the light emitting device 1 that have already been described.
Note that the ten light emitting elements 20 may be, for example, five light emitting elements connected in series and connected in parallel. The manner of connection can be changed depending on the characteristics of the light emitting element 20.

In the light emitting device 1B, the light emitting element 20 can include a first light emitting element whose peak emission wavelength is a first wavelength and a second light emitting element whose peak emission wavelength is a second wavelength different from the first wavelength. In this case, one of the first frame 31 and the second frame 32 has a higher light reflectance at the first wavelength than the second wavelength, and the other of the first frame 31 and the second frame 32 has a higher light reflectance at the first wavelength than at the second wavelength. It is preferable that the light reflectance at the wavelength is greater than the light reflectance at the first wavelength.
As a result, the light emitting device 1B can match the wavelength bands in which the light reflectance of the first frame 31 and the second frame 32 is high to each of the different light emission peak wavelengths of the light emitting element 20, and the first light emitting element and the second light emitting element The light reflectivity of the light from the element can be improved separately.

In the second modification of the method for manufacturing a light emitting device, the light reflectances of the first member 301 and the second member 302 at the light emission peak wavelength of the light emitting element 20 may be the same or different. Further, the order of the coating step S20 may be such that the third member 303 is coated after the first member 301 and the second member 302 are coated.

1 Light-emitting device 1A Light-emitting device (one light-emitting element)
1B Light emitting device (multiple light emitting elements)
10 Substrate 11 Base material 12 Wiring 13 Electrode terminal 14 Bonding wire 15 Protective element 20 Light emitting element 30 Frame 31 First frame 32 Second frame 35 Inclined surface 40 Sealing member 80 Nozzle 81 First nozzle 81A Discharge port (first nozzle )
81B Side (first nozzle)
82 Second nozzle 90 Jet dispenser 300 Frame member 301 First member 301A Material (first member)
302 Second member 302A Material (second member)
303 Third member 340 Recessed portion 350A Inclined surface (coating process)

Claims (17)

Applying a first member onto a substrate on which one or more light emitting elements are arranged so as to surround the light emitting elements at a distance;
a step of applying a second member on the applied first member so as to spaced apart from and surround the light emitting element;
The method for manufacturing a light emitting device, wherein the first member and the second member have light reflectivity, and have different light reflectances at the emission peak wavelength of the light emitting element. The method for manufacturing a light emitting device according to claim 1, wherein the viscosity of the second member is higher than the viscosity of the first member. A third member is applied so as to form an inclined surface continuous with the inner peripheral side surface of the first member, forming an angle of 10 degrees or more and 45 degrees or less with the upper surface of the substrate, and descending toward the light emitting element. further including the process,
3. The method of manufacturing a light emitting device according to claim 1, wherein the third member has light reflectivity and has a different light reflectance from the second member at the emission peak wavelength of the light emitting element. Applying a first member onto a substrate on which one or more light emitting elements are arranged so as to surround the light emitting elements at a distance;
a step of applying a second member on the applied first member so as to spaced apart from and surround the light emitting element;
The step of applying the first member includes applying the first member by discharging it from a nozzle, and applying the first member so that the first member is at a height equal to or higher than the position of the discharge port of the nozzle in a direction perpendicular to the substrate. A method of manufacturing a light emitting device by coating. The base materials of the first member and the second member are the same,
5. The method of manufacturing a light emitting device according to claim 4, wherein in the step of applying the second member, the second member is applied by separating the nozzle from the first member and discharging the second member from the nozzle. The method for manufacturing a light emitting device according to any one of claims 1 to 4, wherein the first member and the second member are made of resin having the same base material. 5. The method of manufacturing a light emitting device according to claim 1, wherein the first member is made of ceramics, and the second member is made of resin. 5. The method of manufacturing a light emitting device according to claim 1, wherein the first member is made of resin, and the second member is made of ceramic. 9. The method for manufacturing a light emitting device according to claim 1, wherein the step of applying the second member includes applying the second member in a plurality of layers. Any one of claims 1 to 9, wherein in the step of applying the second member, the center of the second member in the width direction is located farther from the light emitting element than the center of the first member in the width direction. 1. A method for manufacturing a light emitting device according to item 1. one or more light emitting elements;
a substrate on which the light emitting element is arranged;
a first frame surrounding the light emitting element at a distance on the substrate;
a second frame that surrounds the light emitting element at a distance on the first frame;
A light emitting device in which the first frame and the second frame have light reflectivity, and have different light reflectances at a light emission peak wavelength of the light emitting element. The light emitting device according to claim 11, wherein the first frame has an inclined surface that forms an angle of 10 degrees or more and 45 degrees or less with the upper surface of the substrate and slopes down toward the light emitting element. The light-emitting device according to claim 11 or 12, wherein the first frame and the second frame are made of resin having the same base material. The light emitting device according to claim 11 or 12, wherein the first frame is made of ceramics, and the second frame is made of resin. The light emitting device according to claim 11 or 12, wherein the first frame is made of resin, and the second frame is made of ceramics. The light emitting device according to any one of claims 11 to 15, wherein the light reflectance of the first frame at the light emission peak wavelength of the light emitting element is greater than the light reflectance of the second frame. The light emitting element includes a first light emitting element whose peak emission wavelength is a first wavelength and a second light emitting element whose peak emission wavelength is a second wavelength different from the first wavelength,
One of the first frame and the second frame has a light reflectance at the first wavelength greater than a light reflectance at the second wavelength,
The light emitting device according to any one of claims 11 to 16, wherein the other of the first frame and the second frame has a higher light reflectance at the second wavelength than at the first wavelength. .

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