JP6798279B2 - Manufacturing method of light emitting device - Google Patents

Description

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

Conventionally, there is known a method for manufacturing a light emitting device in which a phosphor layer is provided on each of a plurality of LED chips on one substrate, and then the substrate is divided along a scribe line and separated into individual pieces (. For example, see Patent Documents 1 and 2). According to such a manufacturing method, a plurality of light emitting devices can be efficiently manufactured.

Japanese Patent No. 5175885 Japanese Unexamined Patent Publication No. 2016-146465

In the method for manufacturing a light emitting device described in Patent Document 1, the substrate is divided with the phosphor layer exposed. Usually, in such a dividing step, a cutting method (dicing) using a rotary blade is used. Then, in dicing, water is used for cooling the rotary blade and the work at the time of cutting and for removing shavings. Therefore, there is no problem as long as the phosphor contained in the phosphor layer has a property of not reacting with water such as a YAG phosphor, but a case of having a property of reacting with water such as a KSF phosphor. In the process of dividing the substrate, the phosphor layer comes into contact with water and deteriorates.

In the method for manufacturing a light emitting device described in Patent Document 2, in order to prevent the tool used for cutting from being worn, the substrate is cut by a push-cutting blade, and the covering member on the substrate is cut by a cutting blade. However, since two cutting steps are required to separate the light emitting device, there is a problem that the steps are complicated.

In the method for manufacturing a light emitting device described in Patent Document 2, if a cutting method using water such as dicing is used for cutting the substrate and the covering member, the light emitting device can be separated into individual pieces in one cutting step. However, since the light emitting device is individualized with the phosphor layer exposed, the fluorescence contained in the phosphor layer is similar to the method for manufacturing the light emitting device described in Patent Document 1. If the body has the property of reacting with water, the phosphor layer deteriorates in contact with water.

An object of the present invention is a method for manufacturing a light emitting device capable of efficiently manufacturing a plurality of light emitting devices, in which the phosphor contained in the phosphor layer has a property of reacting with water. However, it is an object of the present invention to provide a method for producing a light emitting device capable of preventing deterioration of the phosphor layer, and a light emitting device having a structure capable of using such a manufacturing method.

One aspect of the present invention provides the following methods for manufacturing a light emitting device [1] to [5] and the light emitting devices [6] to [8] in order to achieve the above object.

[1] A step of cutting a sheet having a phosphor layer containing a phosphor by a cutting method in which the phosphor layer does not come into contact with water and dividing the sheet into a plurality of phosphor-containing members having the phosphor layer, and the plurality. In the step of installing each of the phosphor-containing members of the above on a plurality of light emitting elements, the side surfaces of the plurality of light emitting elements and at least the side surfaces of the plurality of phosphor-containing members are collectively covered with a sealing member, and the fluorescent material is covered. The sealing member is cut by a step of leaving the surface of the fluorescent material layer of the containing member in a state where the surface is not exposed, and the sealing member is cut by a cutting method using water to include the light emitting element, the fluorescent material-containing member, and the sealing member, respectively. A step of obtaining a plurality of light emitting devices, and a method for manufacturing a light emitting device including.

[2] The method for manufacturing a light emitting device according to the above [1], wherein at least a part of the phosphor has a property of reacting with water.

[3] The method for manufacturing a light emitting device according to the above [1] or [2], wherein the sheet is cut by an ultrasonic cutter.

[4] The method for manufacturing a light emitting device according to any one of [1] to [3] above, wherein the sheet is cut so that the arithmetic mean roughness Ra of the cut surface is 100 nm or more.

[5] The phosphor-containing member has a laminated structure of the phosphor layer and the protective layer, and the phosphor layer is installed on the light emitting element so as to face the light emitting element side. The method for manufacturing a light emitting device according to any one of [4].

[6] A light emitting element, a phosphor layer containing a phosphor having a property of reacting with water on the light emitting element, a protective layer on the phosphor layer, the light emitting element, the phosphor layer, and the above. A light emitting device having a sealing member covering a side surface of a protective layer, and having a tapered shape in which the phosphor layer has a width at least in the lateral direction from the light emitting element side to the opposite side.

[7] The light emitting device according to the above [6], wherein the arithmetic average roughness Ra of the side surface of the phosphor layer is 100 nm or more.

[8] The light emission according to the above [6] or [7], wherein the phosphor layer and the protective layer have a tapered shape in which the width at least in the lateral direction increases from the light emitting element side to the opposite side. apparatus.

According to the present invention, there is a case where it is a method of manufacturing a light emitting device capable of efficiently manufacturing a plurality of light emitting devices and the phosphor contained in the phosphor layer has a property of reacting with water. However, it is possible to provide a method for manufacturing a light emitting device capable of preventing deterioration of the phosphor layer, and a light emitting device having a structure capable of using such a manufacturing method.

1 (a) and 1 (b) are vertical cross-sectional views of the light emitting device according to the first embodiment. 2 (a) to 2 (e) are perspective views showing a manufacturing process of the light emitting device according to the first embodiment. 3 (a) and 3 (b) are vertical cross-sectional views of a modified example of the light emitting device according to the first embodiment. 4 (a) and 4 (b) are vertical cross-sectional views of a modified example of the light emitting device according to the first embodiment. 5 (a) and 5 (b) are vertical cross-sectional views of the light emitting device according to the second embodiment. FIG. 6 is a conceptual diagram showing a process of forming a laminate of a phosphor layer and a protective layer, which are phosphor-containing members. FIG. 7A is a scanning electron microscope (SEM) observation image of the cut surface of the phosphor layer and the protective layer cut by the ultrasonic cutter. FIG. 7B is an SEM observation image of the cut surface of the phosphor layer and the protective layer cut by the push-cutting blade.

[First Embodiment]
(Configuration of light emitting device)
1 (a) and 1 (b) are vertical cross-sectional views of the light emitting device 1 according to the first embodiment. FIG. 1A shows a cross section in the longitudinal direction of the light emitting device 1, and FIG. 1B shows a cross section in the lateral direction of the light emitting device 1 orthogonal to the cross section of FIG. 1A.

The light emitting device 1 is electrically connected to the substrate 10, the electrode 11 formed on one surface of the substrate 10, the electrode 12 formed on the other surface of the substrate 10, and the electrode 11. A light emitting element 13 mounted on one surface of the substrate 10, a phosphor layer 14 on the light emitting element 13, a protective layer 15 on the phosphor layer 14, a light emitting element 13, a phosphor layer 14, and a protective layer. It has a sealing member 16 that covers the side surface of the fifteen.

The substrate 10 is, for example, an Al ₂ O ₃ substrate, a ceramic substrate such as an Al N substrate, a metal substrate such as an Al substrate or Cu substrate whose surface is covered with an insulating film, or a glass epoxy substrate. The electrode 11 and the electrode 12 are made of a conductive material such as Cu.

The light emitting element 13 is, for example, an LED chip or a laser diode chip. The light emitting element 13 is typically a flip-chip type element, but may be a face-up type. The number of light emitting elements 13 included in the light emitting device 1 is not particularly limited.

The phosphor layer 14 is made of, for example, a dispersed resin such as a silicone resin or an epoxy resin, or a transparent member such as glass, and contains a particulate phosphor. The fluorescent color of the phosphor contained in the phosphor layer 14 is not particularly limited. Further, the phosphor layer 14 may contain a plurality of types of phosphors. The light emitting element 13 functions as an excitation light source for the phosphor contained in the phosphor layer 14, and the mixed color of the light emitting color of the light emitting element 13 and the light emitting color of the phosphor layer 14 becomes the light emitting color of the light emitting device 1. For example, when the emission color of the light emitting element 13 is blue and the emission color of the phosphor layer 14 is yellow, the emission color of the light emitting device 1 is white.

In the present embodiment, the phosphor layer 14 does not come into contact with water throughout the entire process, including the step of individualizing the light emitting device 1 by dicing. Therefore, according to the present embodiment, the phosphor contained in the phosphor layer 14 has a property of reacting with water (when the phosphor layer 14 contains a plurality of types of phosphors, at least a part thereof is water. Even in the case of (having a property of reacting with water), deterioration of the phosphor layer 14, that is, deterioration of the function as the phosphor layer due to contact with water can be prevented.

Here, examples of the fluorescent substance having the property of reacting with water include K ₂ SiF ₆ : Mn ⁴⁺ (KSF) fluorescent substance, (Ba, Sr, Ca) ₂ SiO ₄ : Eu ²⁺ and Sr ₃ SiO ₅ : Eu. ^Examples thereof include silicate phosphors such as ^2+, sulfide phosphors such as (Sr, Ca) S: Eu ²⁺ and SrGa ₂ S ₄ : Eu ^2+, and quantum dot phosphors such as CdSe. ..

The concentration of the phosphor in the phosphor layer 14 may be uniform, but may be non-uniform, and it is preferable to have a concentration gradient in the thickness direction in which the concentration becomes higher as it is closer to the light emitting element 13. ..

The protective layer 15 is made of a resin such as a silicone resin or an epoxy resin or a transparent member such as glass, and is protected by covering the upper surface of the phosphor layer 14 in a step of dicing the light emitting device 1 into pieces. It has a function of preventing the phosphor layer 14 from coming into contact with water.

The phosphor layer 14 and the protective layer 15 are formed as a set of members (hereinafter, referred to as phosphor-containing members), and then are installed on the light emitting element 13.

The sealing member 16 is made of, for example, a resin such as a silicone resin or an epoxy resin, glass, or the like. The sealing member 16 may be a white member containing light-reflecting particles such as titanium oxide, or a transparent member containing no additives.

(Manufacturing method of light emitting device)
2 (a) to 2 (e) are perspective views showing a manufacturing process of the light emitting device 1 according to the first embodiment.

First, as shown in FIG. 2A, a substrate 10 having a plurality of electrodes 11 and 12 on the surface is prepared. Note that FIG. 2A shows a part of the substrate 10.

Next, as shown in FIG. 2B, electrodes (not shown) of the plurality of light emitting elements 13 are connected to the plurality of electrodes 11 on the substrate 10 by conductive members such as solder bumps.

Next, as shown in FIG. 2C, the phosphor layer 14 and the protective layer 15 integrally formed as the phosphor-containing member are formed so that the phosphor layer 14 faces the light emitting element 13 side. Install on top. The phosphor layer 14 and the protective layer 15 integrally formed as a phosphor-containing member cut a sheet in which the phosphor layer 14 and the protective layer 15 are laminated by a cutting method using an ultrasonic cutter or the like without using water. , Obtained by dividing.

Next, as shown in FIG. 2D, the side surfaces of the plurality of light emitting elements 13, the phosphor layer 14, and the protective layer 15 are collectively covered with the sealing member 16. Specifically, for example, the sealing member 16 is applied onto the substrate 10 to a height at which the light emitting element 13, the phosphor layer 14, and the protective layer 15 are embedded, and then the sealing member 16 is polished. The upper surfaces of the plurality of protective layers 15 are exposed. In this state, the upper surface of the phosphor layer 14 is covered with the protective layer 15 and the side surface is covered with the sealing member 16, so that the surface is not exposed.

The adhesiveness and adhesiveness of the sealing member 16 may be used for joining the phosphor layer 14 and the protective layer 15 to the sealing member 16, but the phosphor layer 14 and the protective layer 15 are sealed. A resin having better adhesiveness and adhesiveness than the sealing member 16 may be used at the interface with the member 16.

Next, as shown in FIG. 2E, the sealing member 16, the substrate 10, and in some cases the electrodes 11 and 12 are cut by a cutting method using water such as dicing, and a plurality of light emitting devices 1 are formed. obtain.

At this time, since the surface of the phosphor layer 14 is not exposed and does not appear on the cut surface, it does not come into contact with water, and the phosphor layer 14 contains a phosphor having a property of reacting with water. Even if it is present, the function of the phosphor layer 14 is not deteriorated. In this step, materials having different hardness such as the sealing member 16, the substrate 10, the electrode 11, and the electrode 12 are continuously cut, so that it is difficult to cut properly without using a rotary blade. That is, it is difficult to properly cut using a cutting method that does not use water.

(Modified example of light emitting device)
3 (a) and 3 (b) are vertical cross-sectional views of a light emitting device 2 which is a modification of the light emitting device 1. FIG. 3A shows a cross section in the longitudinal direction of the light emitting device 2, and FIG. 3B shows a cross section in the lateral direction of the light emitting device 2 orthogonal to the cross section of FIG. 3A.

The light emitting device 2 has a sealing member 20 having a shape in which the protective layer 15 of the light emitting device 1 and the sealing member 16 are integrated. The sealing member 20 is, for example, a transparent member made of a resin such as a silicone resin or an epoxy resin, glass, or the like.

In the light emitting device 2, since the sealing member 20 also functions as the protective layer 15 of the light emitting device 1, it is not necessary to use the protective layer 15. Therefore, in the light emitting device 2, only the phosphor layer 14 is installed on the light emitting element 13 as a phosphor-containing member in the manufacturing process shown in FIG. 2 (c) of the light emitting device 1.

The sealing member 20 is raised to a height such that the light emitting element 13 and the phosphor layer 14 are embedded on the substrate 10 instead of the sealing member 16 in the manufacturing process shown in FIG. 2D of the light emitting device 1, for example. After the coating, the phosphor layer 14 is polished to a height at which the upper surface is not exposed.

FIG. 4A is a vertical cross-sectional view of the light emitting device 3 which is a modified example of the light emitting device 1. FIG. 4B is a vertical cross-sectional view of the light emitting device 4, which is a modified example of the light emitting device 2.

The light emitting device 3 and the light emitting device 4 are different from the light emitting device 1 and the light emitting device 2, respectively, in that they do not include the substrate 10. In the light emitting device 3 and the light emitting device 4, the light emitting element 13, the phosphor layer 14, and the like are installed on a holding member instead of the substrate 10, and the light emitting device 3 and the light emitting device 4 are separated by dicing or the like, and then the holding member is used. It is peeled off from the light emitting device 3 and the light emitting device 4.

Further, the light emitting device 3 and the light emitting device 4 have electrodes 17 for external connection. The electrode 17 may be connected to the light emitting element 13 in advance, or may be connected in the manufacturing process of the light emitting device 3 and the light emitting device 4.

[Second Embodiment]
The second embodiment is different from the first embodiment in the shape of the phosphor layer and the like. The description of the same points as in the first embodiment will be omitted or simplified.

5 (a) and 5 (b) are vertical cross-sectional views of the light emitting device 5 according to the second embodiment. FIG. 5A shows a cross section of the light emitting device 5 in the longitudinal direction, and FIG. 5B shows a cross section of the light emitting device 5 in the lateral direction orthogonal to the cross section of FIG. 5A.

The light emitting device 5 is electrically connected to the substrate 10, the electrode 11 formed on one surface of the substrate 10, the electrode 12 formed on the other surface of the substrate 10, and the electrode 11. A light emitting element 13 mounted on one surface of the substrate 10, a phosphor layer 50 on the light emitting element 13, a protective layer 51 on the phosphor layer 50, a light emitting element 13, a phosphor layer 50, and a protective layer. It has a sealing member 16 that covers the side surface of the 51.

In the light emitting device 5, the phosphor layer 50 and the protective layer 51 integrally formed as the phosphor-containing member have a large width in the lateral direction and the longitudinal direction from the light emitting element 13 side to the opposite side (upper side). It has a tapered shape. The inclined sides of the phosphor layer 50 and the protective layer 51 are continuous.

FIG. 6 is a conceptual diagram showing a step of forming a laminate of the phosphor layer 50 and the protective layer 51, which are phosphor-containing members. In the example shown in FIG. 6, as a cutting method that does not use water, a sheet 60 in which the phosphor layer 50 and the protective layer 51 are laminated is cut using an ultrasonic cutter.

Since the blade 61 of the ultrasonic cutter is inclined and cuts the sheet 60 from the phosphor layer 50 side, a tapered shape is formed in which the width increases from the phosphor layer 50 side toward the protective layer 51 side. When cutting is performed by push-cutting using a push-cutting blade having no inclination, a substantially rectangular parallelepiped phosphor layer 50 and a protective layer 51 can be obtained.

Further, in order to improve the adhesion between the phosphor layer 50 and the protective layer 51 and the sealing member 16, the arithmetic average roughness Ra of the side surface of the phosphor layer 50 and the protective layer 51, which is the cut surface, is 100 nm or more. It is preferably 200 nm or more, and more preferably 200 nm or more. Further, if the arithmetic average roughness Ra is too large, the light extraction efficiency in the light emitting device 5 is lowered, so that it is preferably 2 μm or less.

When an ultrasonic cutter is used, the arithmetic mean roughness Ra of the side surfaces of the phosphor layer 50 and the protective layer 51 can be controlled by adjusting the descending speed of the blade 61 and the amplitude in the vertical direction. In addition, when cutting is performed by push-cutting using a push-cutting blade having no inclination, the arithmetic mean roughness Ra of the side surfaces of the phosphor layer 50 and the protective layer 51 is usually smaller than 100 nm.

FIG. 7A is a scanning electron microscope (SEM) observation image of the cut surface of the phosphor layer and the protective layer cut by the ultrasonic cutter. FIG. 7B is an SEM observation image of the cut surface of the phosphor layer and the protective layer cut by the push-cutting blade.

The phosphor layer shown in FIGS. 7A and 7B is made of a silicone resin containing a KSF phosphor, and the protective layer is made of a silicone resin. The descending speed of the blade of the ultrasonic cutter was 0.25 mm / s, and the amplitude in the vertical direction was 20 μm.

As a result of analysis using an atomic force microscope (AFM), the arithmetic average roughness Ra of the cut surface shown in FIG. 7 (a) is 250 nm, and the arithmetic average roughness Ra of the cut surface shown in FIG. 7 (b) is It was 81.7 nm. Further, since an ultrasonic cutter having a blade inclination angle of 4 ° was used for cutting the phosphor layer 50 and the protective layer 51 shown in FIG. 7A, the inclination angle of the cut surface (fluorescent layer 50 and the protective layer) was used. The angle of 51 from the in-plane direction) was 86 °.

The phosphor layer 50 may have a tapered shape in which the width in the lateral direction increases from the light emitting element 13 side to the opposite side, but the width in the longitudinal direction does not change. For example, the longitudinal side surface of the phosphor layer 50 is formed by cutting with an ultrasonic cutter, and the side surface in the lateral direction is formed by using the side surface of the sheet 60 as it is or by cutting with a push-cutting blade having no inclination. Such a shape can be obtained by doing so.

Further, as shown in FIGS. 5A and 5B, it is preferable that the size of the upper surface of the light emitting element 13 is smaller than the size of the lower surface of the phosphor layer 50. This is because the light emitted from the light emitting element 13 is efficiently injected into the phosphor layer 50.

The light emitting device 5 may have the sealing member 20 of the light emitting device 2 instead of the protective layer 51 and the sealing member 16. In this case, since only the phosphor layer 50 is cut by the ultrasonic cutter, only the phosphor layer 50 has a tapered shape in which the width increases from the light emitting element 13 side to the opposite side (upper side).

(Effect of embodiment)
According to the above embodiment, it is a method for manufacturing a light emitting device capable of efficiently manufacturing a plurality of light emitting devices, and has a property that the phosphor contained in the phosphor layer reacts with water. It is possible to provide a method for manufacturing a light emitting device capable of preventing deterioration of the phosphor layer even in the case, and a light emitting device having a structure capable of using such a manufacturing method.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the invention. In addition, the components of the above-described embodiment can be arbitrarily combined within a range that does not deviate from the gist of the invention.

Moreover, the above-described embodiment does not limit the invention according to the claims. It should also be noted that not all combinations of features described in the embodiments are essential to the means for solving the problems of the invention.

1, 2, 3, 4, 5 Light emitting device 13 Light emitting element 14, 50 Fluorescent layer 15, 51 Protective layer 16, 20 Sealing member

Claims (3)

A step of preparing a phosphor layer containing a fluorescent substance having at least a part of the property of reacting with water, and a sheet having a protective layer that covers one surface of the fluorescent substance layer and prevents the fluorescent substance layer from coming into contact with water. When,
The sheet is cut by an ultrasonic cutter having an inclined blade to form a tapered shape whose width increases from the phosphor layer side to the protective layer side, and the fluorescent layer and the protective layer are formed. The step of dividing the cut surface of the above into a plurality of phosphor-containing members having a predetermined arithmetic mean roughness, and
The plurality of phosphor-containing members are each installed on the plurality of light-emitting elements arranged at predetermined intervals so that the phosphor layers of the plurality of phosphor-containing members face the plurality of light-emitting elements. Process and
The side surfaces of the plurality of light emitting elements and the side surfaces of the plurality of phosphor-containing members are collectively covered with a sealing member that prevents the phosphor layer from coming into contact with water, and the phosphor layer of the phosphor-containing member is covered. And the process of making the surface unexposed
A step of cutting the sealing member by a cutting method using water to obtain a plurality of light emitting devices including the light emitting element, the phosphor-containing member, and the sealing member.
A method for manufacturing a light emitting device including. At least one of a silicate phosphor, a sulfide phosphor, and a quantum dot phosphor is used as the phosphor having a property of reacting with water.
The method for manufacturing a light emitting device according to claim 1. The sheet is cut so that the arithmetic average roughness Ra of the cut surface is 100 nm or more.
The method for manufacturing a light emitting device according to claim 1 or 2.