JP2023140834A - Light-emitting device and method for manufacturing light-emitting device - Google Patents

Abstract

To provide a light-emitting device and a method for manufacturing a light-emitting device, capable of improving light extraction efficiency while suppressing the leakage of a resin material.SOLUTION: A light-emitting device 100 includes: a mounting substrate 10 with wiring electrodes 17, 18, 19 on one surface thereof; a light-emitting element 20 that includes a rectangular-shaped support substrate 21 disposed on the one surface of the mounting substrate, an electrode pad 23 extending along one side of the top surface of the support substrate, and a semiconductor structure layer 22 that is formed in another region of the top surface of the support substrate and that includes a light-emitting layer; metal bumps 28 arranged spaced apart from each other on the electrode pad; metal wires 25 and 27 connected to the wiring electrode and the respective metal bumps; a wavelength conversion layer that contains phosphor particles and translucent spacer particles 45 having a larger particle diameter than the phosphor particles, that employs a translucent resin as a base material, and that covers the semiconductor structure layer on the support substrate and extends to the top of the electrode pad; and a translucent member that is disposed on the wavelength conversion layer, and that covers the top surface of the semiconductor structure layer and extends to the top of the metal bumps.SELECTED DRAWING: Figure 1

Description

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

Conventionally, a substrate, a light emitting element having a semiconductor light emitting layer mounted on the substrate, a wavelength converter that converts the wavelength of light emitted from the light emitting element, and a portion of the wavelength converter excluding the light emitting surface have been described. 2. Description of the Related Art A light-emitting device is known that includes a light reflector that is sealed and reflects light from a light-emitting element and a wavelength converter.

For example, Patent Document 1 describes a substrate, a light emitting element mounted on the substrate, a light transmitting member disposed on the upper surface of the light emitting element, and a light transmitting member disposed between the upper surface of the light emitting element and the lower surface of the light transmitting member. A light-emitting device is disclosed which further includes a light-guiding member made of a resin material that guides light emitted from the light-emitting element to a light-transmitting member.

Japanese Patent Application Publication No. 2010-219324

In the light emitting device described in Patent Document 1, the light guide member is formed from the top surface to the side surface of the light emitting element. When such a light guide member is applied to a light emitting element using a support substrate made of silicon, for example, the light emitted from the light emitting element is guided to the side surface of the support substrate by the light guide member. When the emitted light is guided to the side surface of the support substrate, the emitted light is absorbed by the support substrate, resulting in a problem that the light extraction efficiency of the light emitting device decreases.

In addition, if the light guide member is formed only on the top surface of the light emitting element, if the light transmitting member is mounted at an angle with respect to the top surface of the light emitting element during manufacturing, the resin material of the light guide member may be formed on the top surface of the light emitting element. There is a possibility that a problem may occur in which the liquid leaks from the side surface of the light emitting element.

The present invention has been made in view of the above points, and provides a light emitting device and a light emitting device that can improve the light extraction efficiency of the light emitting device while suppressing problems caused by leakage of resin material to the side surface of the support substrate. The purpose is to provide a manufacturing method for.

A light emitting device according to the present invention includes: a mounting substrate having a wiring electrode on one main surface; a supporting substrate disposed on the one main surface of the mounting substrate and having a rectangular top surface shape; a light emitting element having an electrode pad extending over one region along one side of the upper surface, and a semiconductor structure layer formed on another region of the upper surface of the support substrate and including a light emitting layer; metal bumps spaced apart in a direction along the first side of the support substrate on the electrode pad; metal wires connected to each of the wiring electrodes and the metal bumps; phosphor particles and the metal bumps; A wavelength that includes light-transparent spacer particles having a larger particle size than the phosphor particles and is made of a light-transparent resin as a base material, covers the semiconductor structure layer on the support substrate, and extends to above the electrode pad. It is characterized by comprising a conversion layer, and a light-transmitting member disposed on the wavelength conversion layer, covering the upper surface of the semiconductor structure layer, and extending to above the metal bumps.

1 is a top view of a light emitting device according to an example of the present invention. 1 is a sectional view of a light emitting device according to an example of the present invention. 1 is a sectional view of a light emitting device according to an example of the present invention. 1 is a diagram showing a manufacturing flow of a light emitting device according to an example of the present invention. FIG. 3 is a diagram showing the application position of wavelength conversion resin during manufacturing of a light emitting device according to an example of the present invention. FIG. 3 is a diagram showing the application position of wavelength conversion resin during manufacturing of a light emitting device according to an example of the present invention. FIG. 3 is a diagram schematically showing wetting and spreading of a wavelength conversion resin during manufacturing of a light emitting device according to an example of the present invention. FIG. 3 is a diagram schematically showing wetting and spreading of a wavelength conversion resin during manufacturing of a light emitting device according to an example of the present invention. FIG. 3 is a diagram schematically showing wetting and spreading of a wavelength conversion resin during manufacturing of a light emitting device according to an example of the present invention. FIG. 3 is a diagram schematically showing wetting and spreading of a wavelength conversion resin during manufacturing of a light emitting device according to an example of the present invention. FIG. 3 is a diagram schematically showing wetting and spreading of a wavelength conversion resin during manufacturing of a light emitting device according to an example of the present invention. FIG. 3 is a diagram schematically showing the inclination of a light-transmitting member during manufacturing of a light-emitting device according to an example of the present invention. FIG. 3 is a diagram schematically showing the inclination of a light-transmitting member during manufacturing of a light-emitting device according to an example of the present invention. FIG. 3 is a top view of a light emitting device of a comparative example. FIG. 3 is a cross-sectional view of a light emitting device of a comparative example. FIG. 3 is a diagram showing a luminance distribution of a light emitting device according to an example of the present invention. FIG. 2 is an enlarged cross-sectional view of the vicinity of an electrode pad of a light emitting device according to Example 1 of the present invention.

Examples of the present invention will be described in detail below. In the following description and accompanying drawings, substantially the same or equivalent parts are designated by the same reference numerals.

The configuration of a light emitting device 100 according to Example 1 will be described with reference to FIGS. 1 to 3. FIG. 1 is a top view of a light emitting device 100 according to Example 1. 2 is a cross-sectional view of the light emitting device 100 shown in FIG. 1 taken along line AA. 3 is a cross-sectional view of the light emitting device 100 shown in FIG. 1 taken along line BB.

(Light emitting device 100)
The light emitting device 100 includes a substrate structure 10 having a concave portion on the upper surface, a light emitting element 20 disposed on the bottom surface of the concave portion of the substrate structure 10, and a light transmitting element 20 disposed on the upper surface of the light emitting element 20 via a wavelength conversion layer 40. It has a member 50. The light emitting device 100 also includes a first mounting electrode 15, a second mounting electrode 16, a first wiring electrode 17, a second wiring electrode 18, and a second mounting electrode 15, which are respectively formed on the bottom surface of the recess of the substrate structure 10. 3 wiring electrodes 19 and a protection element 30 disposed on the bottom surface of the recess of the substrate structure 10.

Further, the light emitting element 20 has a support substrate 21 having a rectangular upper surface shape and having one side 21E, and a rectangular upper surface shape arranged at a distance from each other on the upper surface of the supporting substrate 21. It includes a semiconductor structure layer 22 and an electrode pad 23.

In the following description, the direction on the side where the recessed portion of the substrate structure 10 opens is assumed to be upward.

Note that the line BB shown in FIG. 1 is a straight line passing through the center point of the upper surface of the semiconductor structure layer 22 of the light emitting element 20 and perpendicular to the side 21E when viewed from above. Further, the dashed-dotted line perpendicular to BB shown in FIG. 1 is a straight line passing through the center point of the upper surface of the semiconductor structure layer 22 of the light emitting element 20 and parallel to the side 21E.

Further, the central axis O shown in FIGS. 1 to 3 passes through the point where the line BB intersects with the dashed line, that is, the center point of the upper surface of the semiconductor structure layer 22, and is perpendicular to the upper surface of the semiconductor structure layer 22. This is the axis line.

(Substrate structure 10)
The substrate structure 10 as a mounting board is a structure made of an insulating material and has a rectangular top surface and a recessed portion on the top surface. As shown in FIGS. 2 and 3, the substrate structure 10 includes a flat plate portion 11 on a flat plate and a frame-shaped frame portion 13 disposed on the upper surface of the flat plate portion 11.

The flat plate portion 11 is an insulating substrate with a rectangular top surface shape. The frame portion 13 is a member having a frame shape that is opened on the upper surface of the flat plate portion 11 so that a central region of the upper surface of the flat plate portion 11 is exposed. That is, the frame portion 13 protrudes upward in the outer edge region of the upper surface of the flat plate portion 11 and functions as a wall portion surrounding the central portion of the upper surface of the flat plate portion 11 . Therefore, in the substrate structure 10, a recessed portion that is open upward is formed by the inner surface of the opening of the frame portion 13 and the upper surface of the flat plate portion 11.

For the flat plate portion 11 and the frame portion 13, for example, ceramic such as aluminum nitride (AlN) can be used as a base material. In this embodiment, the flat plate part 11 and the frame part 13 are made of AlN, which has insulation properties and high thermal conductivity, as a base material. Further, in this example, the flat plate part 11 and the frame body part 13 were formed separately, and the frame body part 13 was bonded to the upper surface of the flat plate part 11 using an adhesive (not shown) to form the substrate structure 10. Note that it is also possible to use a substrate structure 10 in which the flat plate portion 11 and the frame portion 13 are integrally molded.

The first mounting electrode 15, the second mounting electrode 16, the first wiring electrode 17, the second wiring electrode 18, and the third wiring electrode 19 are each formed of a conductive metal on the upper surface of the flat plate portion 11. ing. The first and second mounting electrodes 15 and 16 and the first, second and third wiring electrodes 17, 18 and 19 are each exposed on the bottom surface of the recessed portion of the substrate structure 10, respectively. The first and second mounting electrodes 15 and 16 and the first, second and third wiring electrodes 17, 18 and 19 are formed by patterning a metal made of copper (Cu) on the upper surface of the flat plate part 11, for example. Nickel (Ni) and gold (Au) are layered in this order on its surface.

The first mounting electrode 15 is an element mounting electrode on which the light emitting element 20 is mounted. Further, the second mounting electrode 16 is an element mounting electrode on which the protection element 30 is mounted.

The first, second and third wiring electrodes 17, 18 and 19 are provided on the upper surface of the light emitting element 20 and the protection element 30 by the first, second and third connection wires 25, 27 and 37, respectively. It functions as a bonding pad that is electrically connected to the electrode pad. That is, the flat plate part 11 is provided with first and second mounting electrodes 15 and 16 and first, second and third wiring electrodes 17, 18 and 19 on the upper surface which is the main surface of 1, and has light emitting elements 20 and It functions as a mounting board on which the protection element 30 is mounted.

In this embodiment, each of the first, second, and third wiring electrodes 17, 18, and 19 is arranged between, for example, the upper surface of the flat plate portion 11, the upper surface of the flat plate portion 11, and the lower surface of the frame portion 13, Alternatively, it is formed to be electrically conductive by a wiring pattern (not shown) provided between the upper surface and the lower surface of the flat plate portion 11. In addition, the first, second, and third wiring electrodes 17 , 18 , and 19 may be formed by penetrating electrodes (not shown) penetrating from the upper surface to the lower surface of the flat plate portion 11 or at parts of the side surfaces of the flat plate portion 11 . It is electrically connected to a first external electrode formed on the lower surface of the substrate structure 10 via side wiring (not shown) formed from the upper surface to the lower surface.

Similarly, the first mounting electrode 15 and the second mounting electrode 16 are also electrically connected, and are electrically connected to the second external electrode separated from the first external electrode by the through electrode or side wiring. It is connected to the.

(Light emitting element 20)
The light emitting element 20 is a semiconductor light emitting element, such as a light emitting diode (LED), arranged on the first mounting electrode 15 of the substrate structure 10 with a conductive element bonding layer 60 interposed therebetween. In this example, an LED element that emits blue light was used as the light emitting element 20.

The light emitting element 20 includes a support substrate 21 made of conductive silicon (Si) and having a rectangular upper surface shape with one side 21E. Further, the light emitting element 20 has a semiconductor structure layer having a rectangular upper surface shape and having a structure in which a p-type semiconductor layer, a light-emitting layer having a quantum well structure, and an n-type semiconductor layer are stacked in this order with a reflective electrode layer interposed therebetween. 22 is bonded onto the upper surface of the support substrate 21.

Further, the light emitting element 20 is formed on the upper surface of the support substrate 21 so as to be spaced apart from the semiconductor structure layer 22 by a predetermined distance, and is formed so as to extend in a region along the side 21E of the support substrate 21. An electrode pad 23 having a rectangular upper surface shape is provided. Further, the electrode pad 23 has a conductive light-reflective metal film made of gold (Au) on the outermost surface.

In this embodiment, the support substrate 21 has a rectangular upper surface shape with the first side 21E as the short side. Furthermore, the semiconductor structure layer 22 has a square top surface shape on the top surface of the support substrate 21, with sides having a length smaller than the short sides of the support substrate 21. Further, the electrode pad 23 has a rectangular top surface shape with a long side extending along the side 21E and having approximately the same length as the side of the top surface of the semiconductor structure layer 22.

That is, the light emitting element 20 of the present example has an electrode pad 23 formed on the upper surface of the support substrate 21 so as to extend over one area along the side 21E, and an electrode pad 23 formed at a predetermined interval from the electrode pad 23. Semiconductor structure layers 22 formed in other spaced apart regions are arranged. In the light emitting element 20 used in this example, the area of the semiconductor structure layer 22 is about 4/5 and the area of the electrode pad 23 is about 1/10 when viewed from above.

The light emitting element 20 is arranged in a first direction through the element bonding layer 60 in a direction in which the upper surface of the supporting substrate 21 on which the semiconductor structure layer 22 and the electrode pads 23 are provided faces upwardly with respect to the upper surface of the flat plate part 11 of the substrate structure 10. It is arranged on the mounting electrode 15 of. That is, the light emitting element 20 is bonded onto the first mounting electrode 15 with the lower surface of the support substrate 21 (the back surface of the light emitting element 20) facing the first mounting electrode 15.

In the light emitting element 20, the n-type semiconductor layer of the semiconductor structure layer 22 and the support substrate 21 are electrically connected, and the p-type semiconductor layer of the semiconductor structure layer 22 and the electrode pad 23 are electrically connected. Therefore, in the light emitting device 20, the support substrate 21 electrically connected to the n-type semiconductor layer functions as a cathode of the light emitting device 20, and the electrode pad 23 electrically connected to the p-type semiconductor layer functions as an anode. .

Further, the light emitting element 20 has, for example, a bottom electrode (not shown) including a metal layer such as gold (Au) on the bottom surface of the support substrate 21, and the bottom electrode and the first mounting electrode 15 are connected to each other. They are bonded via a conductive element bonding layer 60.

The element bonding layer 60 is a bonding layer that has conductivity and bonds the first mounting electrode 15 of the substrate structure 10 and the lower surface electrode of the light emitting element 20. In this embodiment, the light emitting element 20 is bonded to the element bonding layer 60 using a eutectic layer of gold tin (AuSn).

(Protective element 30)
The protection element 30 is, for example, a reverse voltage protection element such as a Zener diode. The protection element 30 operates to protect the light emitting element 20 when an overvoltage is applied to the light emitting element 20 from the outside (for example, due to static electricity, etc.). The protection element 30 includes a bonding electrode (not shown) that is an anode electrode on the lower surface, and is bonded and electrically connected to the second mounting electrode 16 via the element bonding layer 60. Furthermore, the protection element 30 includes an electrode pad 33, which is a cathode electrode, on the upper surface.

Further, the protection element 30 is connected to the light emitting element 20 so that the polarities thereof are opposite to each other.

(connection wire)
The first connection wire 25 is a bonding wire that connects the electrode pad 23 and the first wiring electrode 17. The first connection wire 25 has one end connected to the electrode pad 23 via a metal bump 26 formed on the electrode pad 23, and the other end connected to the first wiring electrode 17.

The second connection wire 27 is a bonding wire that connects the electrode pad 23 and the second wiring electrode 18. The second connection wire 27 has one end connected to the electrode pad 23 via a metal bump 28 formed on the electrode pad 23, and the other end connected to the second wiring electrode 18.

Therefore, in the light emitting device 20, the cathode of the semiconductor structure layer 22 is connected to the first mounting electrode 15 via the support substrate 21, and the anode of the semiconductor structure layer 22 is connected to the electrode pad 23, the first connection wire 25, and the second mounting electrode 15. It is connected to each of the first wiring electrode 17 and the second wiring electrode 18 via a connecting wire 27 .

The metal bumps 26 and the metal bumps 28 are provided on the upper surface of the electrode pad 23 of the light emitting element 20 so as to be spaced apart from each other in the direction along the side 21E of the support substrate 21. Specifically, as shown in FIG. 2, each of the metal bumps 26 and 28 is provided on the electrode pad 23 in an area within a distance BA from both ends in the direction along the side 21E of the support substrate 21. It is being

It is preferable that the distance BA is 1/4 or less of the length PW in the direction from the end of the electrode pad 23 to the side 21E of the support substrate 21 (BA≦PW/4). Preferably, it is 1/5 or less (BA≦PW/5).

Further, as shown in FIGS. 1 and 2, the first and second connection wires 25 and 27 in the electrode pad 23 area extend in the direction along the side of the support substrate 21 when viewed from above and horizontally from the light emitting element 20. It is arranged so as to be substantially parallel to 21E. Further, the first and second connection wires 25 and 27 are arranged so as to be spaced apart from the electrode pad 23 and the light-transmitting member 50 when viewed horizontally.

In this way, by providing the first and second connection wires 25 and 27 at the ends of the electrode pad 23 and providing them approximately parallel to the side 21E, the precursor resin of the wavelength conversion layer 40 leaks during manufacturing. This can be prevented (details will be described later).

The third connection wire 37 is a bonding wire that connects the electrode pad 33 and the third wiring electrode 19. The third connection wire 37 has one end connected to the electrode pad 33 via a metal bump 38 formed on the electrode pad 33, and the other end connected to the third wiring electrode 19.

In this embodiment, gold (Au) is used for each metal bump and each connection wire material, the height of the metal bumps 26, 28, and 38 is approximately 20 μm, and the first, second, and third connection wires 25, The outer diameters of 27 and 37 are 30 μm. That is, the height from the bottom surface of each metal bump to the top of the connecting wire is approximately 50 μm.

(Wavelength conversion layer 40)
The wavelength conversion layer 40 is a wavelength conversion unit that converts incident light into light with a longer wavelength and outputs the light. The wavelength conversion layer 40 consists of a resin material having translucency, and phosphor particles and spacer particles 45 dispersed in the resin material.

In the following description, the resin material containing phosphor particles in the wavelength conversion layer 40 will be described as the wavelength conversion resin 43. That is, the wavelength conversion layer 40 is a layer in which spacer particles 45 are dispersed in a wavelength conversion resin 43 containing phosphor particles.

The wavelength conversion resin 43 is disposed on the upper surface of the light emitting element 20 so as to cover the semiconductor structure layer 22 on the upper surface of the support substrate 21 and the upper surface of the electrode pad 23 . The wavelength conversion resin 43 also functions as an adhesive that optically couples and adheres the upper surface of the light emitting element 20 and the lower surface of the transparent member 50 disposed on the upper surface of the wavelength conversion layer 40.

The spacer particles 45 are, for example, spherical particles having translucency and made of soft glass or resin. The spacer particles 45 are dispersed within the wavelength conversion layer 40 so as to fit within the upper surface of the semiconductor structure layer 22 of the light emitting element 20. Furthermore, the spacer particles 45 are in contact with both the upper surface of the semiconductor structural layer 22 and the lower surface of the light-transmitting member 50 that faces the upper surface of the semiconductor structural layer 22 . Thereby, the spacer particles 45 can make the upper surface of the semiconductor structure layer 22 and the lower surface of the light-transmitting member 50 substantially parallel to each other at a predetermined distance depending on the outer diameter of the spacer particles 45 .

In this example, thermosetting silicone resin was used as the resin material. Further, in this example, particles of yttrium aluminum garnet (YAG:Ce, Y ₃ Al ₅ O ₁₂ :Ce) doped with cerium (Ce) and having a particle size of 5 μm to 30 μm were used as the phosphor particles. In addition, in this embodiment, the content of phosphor particles in the wavelength conversion resin 43 is adjusted so that the wavelength conversion resin 43 converts a part of the blue light emitted by the light emitting element 20 into yellow light and emits white light. .

Further, in this example, soft glass having an outer diameter of approximately 70 μm was used as the spacer particles 45. Therefore, the phosphor particles can be suspended in the wavelength conversion layer 40, and the first and second connection wires 25 and 27 can be separated from the upper surface of the light emitting element 20 and the lower surface of the light-transmitting member 50.

(Transparent member 50)
The light-transmitting member 50 has a plate-like shape and is arranged on the upper surface of the light emitting element 20 with the wavelength conversion layer 40 interposed therebetween. The light-transmitting member 50 is made of glass or alumina (Al ₂ O ₃ ), for example, and is a non-transparent member that allows the emitted light of the light-emitting element 20 and the fluorescence of the wavelength conversion layer 40 that enter from the bottom surface to be emitted from the top surface of the light-transmitting member 50 . It is a scattering and translucent member. That is, the upper surface of the light-transmitting member 50 is the light emitting device 100 .

The light-transmitting member 50 has a shape in which the lower surface facing the upper surface of the light emitting element 20 covers the upper surface of the semiconductor structure layer 22 and extends to the upper surface of the electrode pad 23 when viewed from above. In other words, the light-transmitting member 50 is disposed on the wavelength conversion layer 40, covers the upper surface of the semiconductor structure layer 22, and extends above the metal bumps 26 and 28 on the electrode pad 23.

In this embodiment, the transparent member 50 made of glass has a rectangular cross-sectional shape, and is formed so that its outer shape when viewed from above is approximately the same as the upper surface of the light emitting element 20.

(Coating member 70)
The covering member 70 is a light reflecting member that reflects light directed to the sides of the wavelength conversion layer 40 and the transparent member 50. The covering member 70 covers the upper surface of the flat plate portion 11, which is the concave portion of the substrate structure 10, the side surface of the light emitting element 20, the side surface of the wavelength conversion layer 40, and the side surface of the transparent member 50, and exposes the upper surface of the transparent member 50. It is arranged in a region surrounded by the inner surface of the frame body part 13 so as to be.

The covering member 70 is, for example, a resin material that contains light-scattering particles and has a light-reflecting property that reflects light emitted from the light-emitting element 20 and the wavelength conversion layer 40 . In this example, a thermosetting silicone resin in which titanium oxide (TiO ₂ ) particles, which are light-scattering particles, were dispersed was used.

(Method for manufacturing light emitting device 100)
Next, a method for manufacturing the light emitting device 100 of this example will be described using FIGS. 4 to 11.

FIG. 4 is a diagram showing a manufacturing flow of the light emitting device 100 according to Example 1 of the present invention. Moreover, FIGS. 5 and 6 are diagrams showing the coating position of the precursor resin 43M of the wavelength conversion layer 40. Note that FIGS. 5, 8, and 11 show cross sections along the line AA shown in FIG. 1.

(Step S11)
First, as shown in FIGS. 1 to 3, a flat plate part 11 is provided with first and second mounting electrodes 15, 16 and first, second, and third wiring electrodes 17, 18, 19 on the upper surface, and A step of preparing a substrate structure 10 consisting of a frame portion 13 disposed on the upper surface of the flat plate portion 11 and opened to expose the upper surface of the flat plate portion 11 is performed (step S11, substrate preparation step). In this step, the flat plate part 11 made of AlN was plated with Cu, Ni, and Au in this order so as to form the patterns of the respective mounting electrodes and wiring electrodes. Further, the frame body part 13 made of AlN was adhered to the upper surface of each of the flat plate parts 11 on which the mounting electrodes and the wiring electrodes were formed, thereby forming the substrate structure 10.

(Step S12)
Next, as shown in FIGS. 1 to 3, a step of bonding the light emitting element 20 and the protection element 30 onto the upper surface of the substrate structure 10 is performed (step S12, element bonding step). In this step, first, a paste containing a mixture of AuSn particles and flux, which is a raw material for the element bonding layer 60, is applied onto the upper surfaces of the first mounting electrode 15 and the second mounting electrode 16. Next, the light emitting element 20 and the protection element 30 are placed on the first mounting electrode 15 and the second mounting electrode so that the lower surfaces of the light emitting element 20 and the protection element 30 are in contact with the respective pastes applied on the corresponding mounting electrodes. It is placed on the upper surface of the mounting electrode 16.

Thereafter, the substrate structure 10 in this state is heated to approximately 300° C. in a reflow oven to melt and solidify the AuSn particles contained in the paste, thereby forming the light emitting element 20, the first mounting electrode 15, and the protective element 30. and the second mounting electrode 16 are formed.

(Step S13)
Next, as shown in FIGS. 1 to 3, a step of forming connection wires connecting the electrode pads formed on the upper surfaces of the light emitting element 20 and the protection element 30 to the corresponding wiring electrodes. (Step S13, wire bonding process). In this step, the substrate structure 10 is set in a bonding device, and each connection wire is formed.

In the first connection wire 25, first, a free air ball is formed at the tip of the metal wire, and the ball is crimped onto one end region of the upper surface of the electrode pad 23 of the light emitting element 20 in the direction along the side 21E of the support substrate 21. . Thereafter, the metal wire of the crimped free air ball is cut to form metal bumps 26.

Next, a free air ball is again formed at the tip of the metal wire, and the metal wire is crimped onto the upper surface of the first wiring electrode 17, and the metal wire is routed in the shape of the first connection wire 25. is crimped onto the metal bump 26. The metal wire is then cut to form the first connection wire 25.

Subsequently, the second connection wire 27 and the third connection wire 37 are formed using the same method.

In addition, in the second connection wire 27, a metal bump 28 is formed on the other end region of the upper surface of the electrode pad 23, which is opposite to the end region where the metal bump 26 of the first connection wire 25 is formed. .

(Step S14)
Next, as shown in FIGS. 5 and 6, a step of applying a resin paste containing spacer particles 45 to a precursor resin 43M, which is a precursor of the wavelength conversion resin 43, on the upper surface of the semiconductor structure layer 22 of the light emitting element 20. (Step S14, wavelength conversion resin coating step). The resin paste has spacer particles 45 made of soft glass dispersed in a precursor resin 43M which is an uncured silicone resin mixed with phosphor particles. In this step, as shown in FIG. 6, the resin paste is applied to the center point of the upper surface of the semiconductor structure layer 22, where the central axis O passes through, as viewed from above. Further, after applying the resin paste, it is allowed to stand still until the spacer particles 45 settle within the precursor resin 43M.

(Step S15)
Next, as shown in FIGS. 2 and 3, a step of placing the light-transmitting member 50 on the resin paste applied on the upper surface of the semiconductor structure layer 22 of the light-emitting element 20 is performed (step S15, the light-transmitting member mounting process). In this step, the precursor resin 43M is spread over the upper surface of the light emitting element 20 by pressing the resin paste on the lower surface of the light-transmitting member 50 whose upper surface is held by a holder.

Since the precursor resin 43M includes spacer particles 45, the upper surface of the light emitting element 20 and the lower surface of the light-transmitting member 50 are spaced at a constant interval. Since the spacer particles 45 are allowed to settle before pressing, they do not move outward from the area of the semiconductor structure layer 22.

Thereafter, the substrate structure 10 is heated at 170° C. for 10 minutes to temporarily harden the precursor resin 43M. Note that the precursor resin 43M may be completely cured in this step to form the wavelength conversion layer 40, or may be left uncured and completely cured at the same time as the coating member 70 described below is formed.

Next, the behavior of wetting and spreading of the precursor resin 43M in step S15 and the effect of arranging the first and second connection wires 25 and 27 at the ends of the electrode pads 23 will be explained using FIGS. 7 to 11. .

7 to 11 are schematic diagrams showing the behavior of the precursor resin 43M wetting and spreading when the light-transmitting member 50 is placed on the light-emitting element 20. 7, FIG. 9, and FIG. 10 are enlarged top views of the light emitting element 20 and the light-transmitting member 50. Further, FIGS. 8 and 11 show a cross section taken along the line AA shown in FIG. 1. Note that in FIGS. 7 to 11, only the light emitting element 20 and the structure on the light emitting element 20 are illustrated, and illustration of other structures is omitted.

First, the light-transmitting member 50 is placed in an upper position away from the light-emitting element 20 and the resin paste in a direction such that the lower surface faces the upper surface of the light-emitting element 20 while holding the upper surface by a collet CT that is a holder. move.

Subsequently, while holding the transparent member 50 in the above state, the collet CT is lowered in a direction perpendicular to the upper surface of the light emitting element 20, that is, in a direction along the central axis O. Therefore, as shown in FIG. 8, as the collet CT descends, the lower surface of the light-transmitting member 50 comes into contact with the precursor resin 43M. Further, the collet CT is lowered in a direction along the central axis O, and the lower surface of the light-transmitting member 50 presses the precursor resin 43M.

By this operation, as shown in FIG. 9, the precursor resin 43M is extruded and spread in a concentric manner. At this time, the wet and spreading edges of the precursor resin 43M reach the other three sides of the support substrate 21 that are different from the side 21E first. Thereafter, it wets and spreads toward the side 21E.

That is, the corner regions of the upper surface of the light emitting element 20 where each of the metal bumps 26 and 28 on the electrode pad 23 are formed, that is, the corner regions of both ends of the side 21E of the support substrate 21 are filled with the precursor resin. This is the corner region where the end of the 43M wetting spread is slowest.

In the light emitting device 100 of this embodiment, as shown in FIG. 9, metal bumps 26 and 28 are formed on the electrode pad 23 at both ends of the support substrate 21 in the direction along the side 21E. Further, in the light emitting device 100 of this embodiment, as shown in FIG. 9, the first and second connection wires 25 and 27 extend in the direction along the side 21E of the support substrate 21 when viewed from above.

As a result, in the light emitting device 100 of this embodiment, when the precursor resin 43M spreads by wetting, the ends of the wetting and spreading reach the first and second connection wires 25 and 27 and the metal bumps 26 and 28. can be delayed. Furthermore, in the light emitting device 100 of this embodiment, as shown in FIG. Since the precursor resin 43M is stretched in the vertical direction, it is possible to make it difficult for the precursor resin 43M to be transmitted to each metal wire.

Therefore, according to the method for manufacturing the light emitting device 100 of this embodiment, it is possible to suppress the problem of the precursor resin 43M dripping on the side surface of the light emitting element 20.

For example, if each metal bump is formed in a central area on the electrode pad 23, and the first and second connection wires 25, 27 are formed from there to cross the side 21E, A problem may occur in which the precursor resin 43M that has arrived drips onto the side surface of the light emitting element 20 due to each metal bump or connection wire. According to the present invention, such problems can be prevented.

(Step S16)
Next, as shown in FIGS. 2 and 3, a step of forming the covering member 70 in the recess formed by the upper surface of the flat plate portion 11 and the inner surface of the frame portion 13 is performed (step S16, covering member forming step). In this step, the recessed portion of the substrate structure 10 is filled with a precursor resin of the coating member 70 made of uncured silicone resin in which TiO ₂ particles are dispersed. The precursor resin is filled in the recess so as to expose the upper surface of the light-transmitting member 50 and cover the side surfaces of the light-transmitting member 50, the upper surface of the flat plate portion 11, and the inner surface of the frame portion 13, respectively.

Thereafter, the substrate structure 10 in this state is heated at 100° C. for 30 minutes and then at 150° C. for 60 minutes to harden the silicone resin and form the wavelength conversion layer 40 and the covering member 70.

By performing the above steps S11 to S16, the light emitting device 100 of this example is manufactured.

(Behavior when wire whiskers occur)
Next, a description will be given of behavior for suppressing defects when wire whiskers occur according to this embodiment. Specifically, in step S13 (wire bonding step) of the method for manufacturing the light emitting device 100 described above, due to poor cutting of the metal wire when forming the metal bumps 26 and 28 or the first and second connection wires 25 and 27, Protruding wire whiskers W may occur on the metal bumps 26 and 28 or the first and second connection wires 25 and 27.

According to this embodiment, even if the wire whisker W has the top at a position higher than the upper end of the spacer particle 45, the inclination of the light-transmitting member 50 is suppressed, and the lower surface of the light-transmitting member 50 and the upper surface of the light-emitting element 20 are It is possible to prevent the precursor resin 43M from leaking out from the area where it is close to.

12 and 13 are diagrams showing the inclination of the light-transmitting member 50 in step S15 when wire whiskers W have occurred. In FIG. 13, a cross section taken along the line AA shown in FIG. 1 is shown.

In the following description, the metal bumps 26 and 28 are formed at both ends of the electrode pad 23 in the direction along the side 21E of the support substrate 21, and the metal bumps 26 and 28 are formed at the ends of the electrode pad 23 in the direction along the side 21E. A case will be described in which they are respectively formed in the central region.

Furthermore, in the following description, a case will be described in which wire whiskers W occur only in the second connection wire 27 among the first connection wire 25 and the metal bump 26 and the second connection wire 27 and the metal bump 28. That is, when the first and second connection wires 25 and 27 are respectively formed in the regions of both ends of the electrode pad 23, a wire whisker W1 occurs in the second connection wire 27, and the first and second connection wires 25 It is assumed that a wire whisker W2 occurs in the second connection wire 27 when wires 27 and 27 are formed in the central region of the electrode pad 23, respectively. Note that the tops of the wire whiskers W1 and W2 have the same height from the top surface of the electrode pad 23 and are higher than the top of the spacer particle 45.

12 and 13, the first and second metal bumps 26 and 28 are formed in the regions of both ends of the electrode pad 23 in the direction along the side 21E of the support substrate 21. The connection wires 25 and 27, the wire whiskers W1, and the transparent member 50 are shown by solid lines. Further, in FIGS. 12 and 13, the metal bumps 26 and 28, the first and second connection wires 25 and 27, the wire whisker W2 and the transparent The optical member 50 is shown by a broken line.

Note that in FIGS. 12 and 13, illustration of the precursor resin 43M and collet CT is omitted.

Further, the X axis shown in FIGS. 12 and 13 is an axis passing through the center point of the upper surface of the semiconductor structure layer 22 in a top view and parallel to the upper surface of the semiconductor structure layer 22 and the side 21E of the support substrate 21. be. Further, the Y-axis is an axis that passes through the center point of the upper surface of the semiconductor structural layer 22 in a top view, is parallel to the upper surface of the semiconductor structural layer 22, and is perpendicular to the side 21E of the support substrate 21.

The light-transmitting member 50 is arranged such that the lower surface of the light-transmitting member 50 is approximately parallel to the upper surface of the light emitting element 20 (the upper surface of the support substrate 21 and the upper surface of the semiconductor structure layer 22) at the start of step S15. It is held at the position of axis O by collet CT.

When the collet CT is lowered along the central axis O while holding the upper surface of the light-transmitting member 50, the lower surface of the light-transmitting member 50 first comes into contact with the wire whisker W1 or W2. Then, when the collet CT further descends, the light-transmitting member 50 tilts so as to be supported by the wire whisker W1 or W2. Thereafter, the lower surface of the light-transmitting member 50 comes into contact with the upper end of one of the spacer particles 45 in a region that is point symmetrical with respect to the central axis O of the wire whisker W1 or W2 when viewed from above. At this time, the lower surface of the light-transmitting member 50 is inclined at an angle along a straight line passing through the top of the wire whisker W1 or W2 and the upper end of the spacer particle 45.

Thereafter, the wire whisker W1 or W2 is crushed by the lower surface of the light-transmitting member 50 by the pressure caused by the lowering of the collet CT, and the light-transmitting member 50 is supported by the plurality of spacer particles 45 and placed at a predetermined position.

In the above-described tilted state, as shown in FIG. 13, when the lower surface of the light-transmitting member 50 contacts the wire whisker W1, the tilt of the light-transmitting member 50 around the Y-axis can be made smaller than when the lower surface contacts the wire whisker W2.

Therefore, according to the light emitting device 100 of this embodiment, by forming the metal bumps 26 and 28 in the regions of both ends of the electrode pad 23 in the direction along the side 21E of the support substrate 21, the precursor resin 43M is It becomes possible to suppress problems caused by leakage.

(Comparative example)
Next, a light emitting device of a comparative example will be described. FIG. 14 is a top view of a light emitting device 200 as a comparative example. Further, FIG. 15 is a cross-sectional view of the light emitting device 200 shown in FIG. 14 at a position corresponding to line CC.

The light emitting device 200 of the comparative example has the same configuration as the light emitting device 100 of the present example except for the wavelength conversion layer 40A and the light-transmitting member 50A. Further, the wavelength conversion layer 40A and the light-transmitting member 50A in the light-emitting device 200 of the comparative example are made of the same materials as the wavelength conversion layer 40 and the light-transmitting member 50 of the light-emitting device 100 of the present example.

The wavelength conversion layer 40A and the transparent member 50A of the comparative example are formed so as to cover only the semiconductor structure layer 22 of the light emitting element 20. That is, the area where the wavelength conversion layer 40A is formed and the area of the light-transmitting member 50A in the light-emitting device 200 of the comparative example are smaller than those of the light-emitting device 100 of the present example. That is, the wavelength conversion layer 40A of the comparative example is formed on the upper surface of the support substrate 21 of the light emitting element 20 so as to cover only the surface of the semiconductor structure layer 22.

Therefore, as shown in FIGS. 14 and 15, in the light emitting device 200 of the comparative example, the electrode pad 23, the first and second connection wires 25 and 27, and the metal bumps 26 and 28 of the light emitting element 20 are formed by the wavelength conversion layer. They are exposed from the transparent member 40A and the transparent member 50A, and are arranged in areas that do not overlap with each other when viewed from above.

Specifically, the area of the light extraction surface, which is the upper surface of the light-transmitting member 50A in the light-emitting device 200 of the comparative example, is about 4/5 of that of the light-transmitting member 50 of the light-emitting device 100 of the example. .

Note that the method of manufacturing the light emitting device 200 of the comparative example is the same as the method of manufacturing the light emitting device 100 of the example.

In the manufacturing method of the light emitting device 200 of the comparative example, in step S14 (wavelength conversion resin coating step), spacer particles made of soft glass are added to the precursor resin 43M, which is an uncured silicone resin, in accordance with the size of the light-transmitting member 50A. The amount of resin paste dispersed with No. 45 was only reduced.

(Comparison of optical properties between Examples and Comparative Examples)
Next, the light emission characteristics of the light emitting device 100 of the example and the light emitting device 200 of the comparative example will be described.

FIG. 16 is a diagram showing the emission luminance distribution of the light emitting device 100 of the example and the light emitting device 200 of the comparative example when viewed from above. Note that in FIG. 16, the brightness distribution of the light emitting device 100 of the example is shown by a solid line, and the brightness distribution of the light emitting device 200 of the comparative example is shown by a broken line.

The horizontal axis in FIG. 16 is the measurement position with the central axis O as the origin, and the vertical axis is the relative brightness. Specifically, the measurement position on the horizontal axis is the line BB shown in FIG. 1 in the light emitting device 100 of the example, and the line CC shown in FIG. 14 in the light emitting device 200 of the comparative example. Further, the relative intensity on the vertical axis is a value expressed with the maximum brightness of each light emitting device as 100%.

Further, on the horizontal axis of FIG. 16, the light emitting region, the pad region, and the frame region are shown separated by two-dot chain lines. The portion not described is the area of the covering member 70. Note that the portion where the luminance of the light emitting region is reduced is where the spacer particles 45 are present.

The luminance distribution of the light emitting device 100 of this embodiment maintains 100% in the light emitting region, 30 to 50% in the pad region, and rapidly decreases in other regions (the region where the covering member 70 is formed), causing noise. level (0.5% or less).

On the other hand, the luminance distribution of the light-emitting device 200 of the comparative example maintains 100% in the light-emitting region, and rapidly decreases outside the light-emitting region (the region where the covering member 70 is formed), reaching the noise level.

As is clear from this result, in the light emitting device 100 of this example, the structure in which the wavelength conversion layer 40 and the light transmitting member 50 are provided even in the upper surface area of the electrode pad 23 makes it possible to increase the light emitting surface. It is said that

Next, we will discuss the results of the total luminous flux. Note that the total luminous flux value will be described as a value (percentage) normalized by the total luminous flux value of the light emitting device 200 of the comparative example. The total luminous flux value of the light emitting device 100 of the example was 104% to 105%, and the total luminous flux value of the light emitting device 200 of the comparative example was 100%. That is, it was confirmed that the total luminous flux value of the light emitting device 100 of the example was improved by 4% to 5%.

As described above, in the light emitting device 100 of Example 1, the structure in which the wavelength conversion layer 40 and the light-transmitting member 50 are provided on the electrode pad 23 makes it possible to expand the light emitting surface to the top of the electrode pad 23. It also makes it possible to improve the total luminous flux.

(About the light emission mode of the light emitting device 100)
Next, the light emission mode of the light emitting device 100 of this example will be described using FIG. 17.

FIG. 17 is an enlarged sectional view of the area around the electrode pad 23 of the light emitting device 100 of this example. Note that FIG. 17 shows a cross section taken along the line BB shown in FIG.

LM1 and LM2 in the figure are lights that have mainly been guided through the non-scattering and transparent light-transmitting member 50 and have come to the area of the electrode pad 23, and the light LM1 is reflected by the surface of the electrode pad 23. The light LM2 is shown as being reflected by, for example, the first connection wire 25 and heading upward.

Since the light-emitting device 100 of this embodiment includes a non-scattering light-transmitting member 50 (glass) on the wavelength conversion layer 40 containing a phosphor, total reflection occurs on the surface of the light-transmitting member 50. The light can easily reach the side surface of the light-transmitting member 50. Therefore, by providing the wavelength conversion layer 40 and the light-transmitting member 50 up to the upper surface of the light-reflective electrode pad 23 along one side 21E of the outer peripheral part of the semiconductor structure layer 22 of the light-emitting element 20, the total luminous flux is This makes it possible to provide a light emitting device with improved performance.

In addition, by providing the first and second connection wires 25 and 27 at both ends of the light-reflective electrode pad 23 along 21E, which is one side of the outer periphery of the semiconductor structure layer 22 of the light emitting element 20, the manufacturing process In this example, the precursor resin 43M was able to suppress leakage from the electrode pad 23 of the light emitting element 20 to the side surface.

Note that the examples described in this specification are not intended to limit the scope of the invention. The described embodiments can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention.

For example, the electrode pads 23 of the light emitting element 20 can be provided in areas along two opposing sides, in areas along two orthogonal sides, or in areas along the entire circumference.

The above-mentioned modifications are also included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

100 Light emitting device 10 Substrate 11 Flat plate portion 13 Frame 15 First mounting electrode 16 Second mounting electrode 17 First wiring electrode 18 Second wiring electrode 19 Third wiring electrode 20 Light emitting element 21 Support substrate 22 Semiconductor structure Layer 23 Electrode pad 25 First connection wire 26 Metal bump 27 Second connection wire 28 Metal bump 30 Protective element 33 Electrode pad 37 Third connection wire 38 Metal bump 40 Wavelength conversion layer 43 Wavelength conversion resin 45 Spacer particles 50 Transparent Optical member 60 Element bonding layer 70 Covering member

Claims (11)

a mounting board having wiring electrodes on the main surface of the board;
a support substrate disposed on the first main surface of the mounting substrate and having a rectangular top surface shape; an electrode pad extending over one area along one side of the top surface of the support substrate; and a light emitting element having a semiconductor structure layer formed in another region of the upper surface of the support substrate and including a light emitting layer;
metal bumps spaced apart in a direction along the first side of the support substrate on the electrode pad;
a metal wire connected to each of the wiring electrode and the metal bump;
The base material includes phosphor particles and translucent spacer particles having a particle size larger than the phosphor particles, and has a translucent resin as a base material, covers the semiconductor structure layer on the support substrate, and is on the electrode pad. a wavelength conversion layer extending to
A light-emitting device comprising: a light-transmitting member disposed on the wavelength conversion layer, covering the upper surface of the semiconductor structure layer and extending to above the metal bumps. Each of the metal bumps has a length from each end in a direction along the first side of the support substrate on the electrode pad to a length in the direction along the first side of the support substrate of the electrode pad. 2. The light emitting device according to claim 1, wherein the light emitting device is formed in an area up to 1/4 of the area. Each of the metal bumps has a length from each end in a direction along the first side of the support substrate on the electrode pad to a length in the direction along the first side of the support substrate of the electrode pad. 2. The light emitting device according to claim 1, wherein the light emitting device is formed in an area up to 1/5 of the area. Each of the metal wires extends from the top surface of each of the metal bumps in a direction along the first side of the support substrate when viewed from above in a direction perpendicular to the top surface of the support substrate. The light emitting device according to any one of claims 1 to 3. 5. The light-emitting device according to claim 1, wherein the electrode pad has a light-reflective conductive layer made of gold on its upper surface. 6. The light emitting device according to claim 1, wherein the spacer particles are made of soft glass or resin. The light emitting device according to any one of claims 1 to 6, wherein an external dimension of the spacer particle is larger than a height dimension from the upper surface of the electrode pad to the upper end of the metal bump and the metal wire. Device. 8. The light emitting device according to claim 1, wherein the wavelength conversion layer covers the semiconductor structure layer and the electrode pad on the upper surface of the support substrate. 9. The light-transmitting member covers the upper surface of the semiconductor structure layer and the upper surface of the electrode pad when viewed from above in a direction perpendicular to the upper surface of the support substrate. The light emitting device according to any one of the items. On the first main surface of the mounting substrate, there is a light-reflecting coating member made of a resin material containing light-scattering particles and covering each side surface of the light-emitting element, the wavelength conversion layer, and the light-transmitting member. 10. The light emitting device according to claim 1, further comprising: a light emitting device. 11. The light emitting device according to claim 10, wherein a frame is disposed on the first main surface of the mounting board, the frame being in contact with an outer edge of the covering member.

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