JP2018088468A - Light-emitting device and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a light-emitting device, by which a plurality of light-emitting devices can be efficiently manufactured and deterioration of a phosphor layer can be prevented even when a phosphor included in the phosphor layer has characteristics reacting with water, and the light-emitting device having a structure that can use the manufacturing method.SOLUTION: A manufacturing method of a light-emitting device includes: a step of cutting a sheet having a phosphor layer 14 and a protective layer 15 by a cutting method in which the phosphor layer 13 is not brought into contact with water and dividing it into a plurality of phosphor containing members each having the phosphor layer 13 and the protective layer 15; a step of installing the plurality of phosphor containing members on a plurality of light-emitting elements 13 respectively; a step of collectively covering side surfaces of the plurality of light-emitting elements 13 and side surfaces of the plurality of phosphor containing members with a sealing member 16 and putting the phosphor layer 14 into a state of not exposing its surface; and a step of cutting the sealing member 16 by a cutting method using water and obtaining the plurality of light-emitting devices.SELECTED DRAWING: Figure 2

Description

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

  Conventionally, a method of manufacturing a light emitting device is known in which a phosphor layer is provided on each of a plurality of LED chips on a single substrate, and then the substrate is divided along a scribe line 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. 5175858 JP-A-2006-146465

  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. In dicing, water is used for cooling the rotary blade and workpiece during cutting and for removing shavings. For this reason, there is no problem as long as the phosphor contained in the phosphor layer has a property that does not react with water such as a YAG phosphor, but it has a property that reacts with water such as a KSF phosphor. In the substrate dividing process, the phosphor layer is deteriorated by contact with water.

  In the method of manufacturing a light emitting device described in Patent Document 2, in order to prevent wear of a tool used for cutting, the substrate is cut with a press cutting blade, and the covering member on the substrate is cut with a cutting blade. However, there is a problem that the process becomes complicated because two cutting steps are required for dividing the light emitting device.

  In addition, in the manufacturing method of the 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 singulated in one cutting step. Although it is thought that it is possible, since the light emitting device is singulated 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. When the body has a property of reacting with water, the phosphor layer is deteriorated by contact with water.

  An object of the present invention is a method of manufacturing a light-emitting device that can efficiently manufacture a plurality of light-emitting devices, in which the phosphor contained in the phosphor layer has a property of reacting with water. However, an object of the present invention is to provide a method for manufacturing a light emitting device that can prevent deterioration of a phosphor layer and a light emitting device having a structure that can use such a manufacturing method.

  In order to achieve the above object, one embodiment of the present invention provides the following light-emitting device manufacturing methods [1] to [5] and light-emitting devices [6] to [8].

[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 contact water, and dividing the sheet into a plurality of phosphor-containing members having the phosphor layer; A step of installing each of the phosphor-containing members on a plurality of light-emitting elements, and simultaneously covering at least the side surfaces of the plurality of light-emitting elements and the plurality of phosphor-containing members with a sealing member, The step of making the phosphor layer of the containing member in a state in which the surface is not exposed and the cutting member using a water cutting method include cutting each of the light emitting element, the phosphor containing member, and the sealing member. A step of obtaining a plurality of light emitting devices.

[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 with an ultrasonic cutter.

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

[5] The above [1], wherein the phosphor-containing member has a laminated structure of the phosphor layer and a protective layer, and is disposed on the light emitting element so that the phosphor layer faces the light emitting element side. The manufacturing method of the light-emitting device of any one of-[4].

[6] A light emitting element, a phosphor layer including 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 And a sealing member that covers a side surface of the protective layer, and the phosphor layer has a tapered shape in which a width in at least a short direction increases from the light emitting element side toward 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 a width in at least a lateral direction increases from the light emitting element side toward the opposite side. apparatus.

  According to the present invention, there is provided a method for manufacturing a light emitting device capable of efficiently manufacturing a plurality of light emitting devices, wherein 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 that can prevent deterioration of the phosphor layer, and a light emitting device having a structure that can use such a manufacturing method.

FIGS. 1A and 1B are vertical sectional views of the light emitting device according to the first embodiment. 2A to 2E are perspective views showing a manufacturing process of the light emitting device according to the first embodiment. FIGS. 3A and 3B are vertical sectional views of a modification of the light emitting device according to the first embodiment. 4A and 4B are vertical sectional views of a modification of the light emitting device according to the first embodiment. FIGS. 5A and 5B are vertical sectional views of the light emitting device according to the second embodiment. FIG. 6 is a conceptual diagram illustrating a process of forming a phosphor body-protective layer laminate that is a phosphor-containing member. FIG. 7A is a scanning electron microscope (SEM) observation image of the cut surfaces of the phosphor layer and the protective layer cut by the ultrasonic cutter. FIG. 7B is an SEM observation image of the cut surfaces of the phosphor layer and the protective layer cut by the press cutting blade.

[First Embodiment]
(Configuration of light emitting device)
FIGS. 1A and 1B are vertical 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 short direction of the light emitting device 1 orthogonal to the cross section of FIG.

  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. Light emitting element 13 mounted on one surface of substrate 10, phosphor layer 14 on light emitting element 13, protective layer 15 on phosphor layer 14, light emitting element 13, phosphor layer 14, and protective layer And a sealing member 16 that covers 15 side surfaces.

The substrate 10 is, for example, a ceramic substrate such as an Al ₂ O ₃ substrate or an AlN substrate, a metal substrate such as an Al substrate or a Cu substrate whose surface is covered with an insulating film, or a glass epoxy substrate. The electrodes 11 and 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 the 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 resin such as a dispersed silicone resin or epoxy resin, or a transparent member such as glass, and includes a particulate phosphor. The fluorescent color of the phosphor contained in the phosphor layer 14 is not particularly limited. Moreover, the phosphor layer 14 may include 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 color mixture of the light emission color of the light emitting element 13 and the light emission color of the phosphor layer 14 becomes the light emission 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 separating the light emitting device 1 by dicing. Therefore, according to the present embodiment, the phosphor included in the phosphor layer 14 has a property of reacting with water (when the phosphor layer 14 includes a plurality of types of phosphors, at least a part of the phosphor layer 14 is water. Even when the phosphor layer 14 is in contact with water, deterioration of the function as the phosphor layer can be prevented.

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

  Note that the concentration of the phosphor in the phosphor layer 14 may be uniform or non-uniform, and preferably has a concentration gradient in the thickness direction in which the concentration increases as the distance from the light emitting element 13 increases. .

  The protective layer 15 is made of a transparent member such as a resin such as a silicone-based resin or an epoxy-based resin or glass, and is protected by covering the upper surface of the phosphor layer 14 in a process of separating the light emitting device 1 by dicing. Thus, the phosphor layer 14 has a function of preventing contact with water.

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

  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 may be a transparent member containing no additive.

(Method for manufacturing light emitting device)
2A to 2E are perspective views showing the 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 electrodes 12 on its surface is prepared. 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 that are integrally formed as a phosphor-containing member are arranged 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 that are integrally formed as a phosphor-containing member are cut from a sheet in which the phosphor layer 14 and the protective layer 15 are laminated by a cutting method that does not use water using an ultrasonic cutter or the like. Obtained by dividing.

  Next, as illustrated in FIG. 2D, the side surfaces of the plurality of light emitting elements 13, the phosphor layers 14, and the protective layer 15 are collectively covered with a sealing member 16. Specifically, for example, after applying the sealing member 16 to such a height that the light emitting element 13, the phosphor layer 14, and the protective layer 15 are embedded on the substrate 10, the sealing member 16 is subjected to a polishing process. The upper surfaces of the plurality of protective layers 15 are exposed. In this state, the phosphor layer 14 is covered with the protective layer 15 on the top surface and covered with the sealing member 16 on the side surface, so that the surface is not exposed.

  In addition, although the adhesiveness and adhesiveness which the sealing member 16 has may be used for joining to the phosphor layer 14 and the protective layer 15 and the sealing member 16, the phosphor layer 14 and the protective layer 15 are sealed. A resin that is more excellent in adhesiveness and adhesiveness than the sealing member 16 may be used at the interface with the member 16.

  Next, as shown in FIG. 2 (e), the sealing member 16, the substrate 10, and in some cases, the electrode 11 and the electrode 12 are cut by a cutting method using water such as dicing, so that a plurality of light emitting devices 1 are obtained. obtain.

  At this time, since the surface of the phosphor layer 14 is not exposed and does not appear on the cut surface, the phosphor layer 14 is not exposed to water, and the phosphor layer 14 includes a phosphor having a property of reacting with water. Even if it is a case, the function of the phosphor layer 14 does not deteriorate. In this step, materials having different hardnesses such as the sealing member 16, the substrate 10, the electrode 11, and the electrode 12 are continuously cut. Therefore, it is difficult to appropriately cut unless a rotary blade is used. That is, it is difficult to appropriately cut using a cutting method that does not use water.

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

  The light emitting device 2 includes a sealing member 20 having a shape in which the protective layer 15 and the sealing member 16 of the light emitting device 1 are integrated. The sealing member 20 is a transparent member made of, for example, 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. For this reason, 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.

  The sealing member 20 is, for example, up to a height at which 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. After the application, a polishing process is performed to such a height that the upper surface of the phosphor layer 14 is not exposed.

  FIG. 4A is a vertical sectional view of a light emitting device 3 which is a modification of the light emitting device 1. FIG. 4B is a vertical cross-sectional view of a light emitting device 4 that is a modification 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 in that the substrate 10 is not included, respectively. In the light-emitting device 3 and the light-emitting device 4, the light-emitting element 13 and the phosphor layer 14 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 into individual pieces by dicing or the like. The light emitting device 3 and the light emitting device 4 are peeled off.

  Further, the light emitting device 3 and the light emitting device 4 have an electrode 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 differs 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.

  FIGS. 5A and 5B are vertical sectional views of the light emitting device 5 according to the second embodiment. 5A shows a cross section in the longitudinal direction of the light emitting device 5, and FIG. 5B shows a cross section in the short direction of the light emitting device 5 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. Light emitting element 13 mounted on one surface of substrate 10, phosphor layer 50 on light emitting element 13, protective layer 51 on phosphor layer 50, light emitting element 13, phosphor layer 50, and protective layer 51, and a sealing member 16 that covers the side surface of 51.

  In the light emitting device 5, the phosphor layer 50 and the protective layer 51 that are integrally formed as a phosphor-containing member have a width in the short side direction and the long side direction from the light emitting element 13 side toward the opposite side (upward). It has a taper shape. The inclined side surfaces of the phosphor layer 50 and the protective layer 51 are continuous.

  FIG. 6 is a conceptual diagram showing a process of forming a laminate of a phosphor layer 50 and a protective layer 51 that are phosphor-containing members. In the example shown in FIG. 6, as a cutting method that does not use water, the 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 taper shape having a width increasing from the phosphor layer 50 side toward the protective layer 51 side is formed. Note that when cutting is performed by pressing using a non-inclined pressing blade, a substantially rectangular parallelepiped phosphor layer 50 and protective layer 51 are obtained.

  In addition, in order to increase 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 surfaces which are cut surfaces of the phosphor layer 50 and the protective layer 51 is 100 nm or more. It is preferable that it is 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, and therefore it is preferably 2 μm or less.

  When the ultrasonic cutter is used, the arithmetic average 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 by press cutting using a non-inclined pressing blade, the arithmetic average 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 surfaces of the phosphor layer and the protective layer cut by the ultrasonic cutter. FIG. 7B is an SEM observation image of the cut surfaces of the phosphor layer and the protective layer cut by the press cutting blade.

  The phosphor layers shown in FIGS. 7A and 7B are 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 vertical amplitude 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. 7A is 250 nm, and the arithmetic average roughness Ra of the cut surface shown in FIG. 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 (the phosphor layer 50 and the protective layer). The angle 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 toward the opposite side, but the width in the longitudinal direction does not change. For example, the side surface in the longitudinal direction of the phosphor layer 50 is formed by cutting using an ultrasonic cutter, and the side surface in the short direction is formed by using the side surface of the sheet 60 as it is, or by cutting using a push cutting blade without inclination. By doing so, such a shape can be obtained.

  5A and 5B, the size of the upper surface of the light emitting element 13 is preferably smaller than the size of the lower surface of the phosphor layer 50. This is for efficiently injecting light emitted from the light emitting element 13 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 toward the opposite side (upward).

(Effect of embodiment)
According to said embodiment, it is a manufacturing method of the light-emitting device which can manufacture a several light-emitting device efficiently, Comprising: The fluorescent substance contained in a fluorescent substance layer has the property to react with water. Even if it is a case, the manufacturing method of the light-emitting device which can prevent deterioration of a fluorescent substance layer, and the light-emitting device which has a structure which can use such a manufacturing method can be provided.

  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 spirit of the invention. In addition, the constituent elements of the above-described embodiment can be arbitrarily combined without departing from the spirit of the invention.

  Moreover, said embodiment does not limit the invention which concerns on a claim. In addition, it should be noted that not all the 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 Phosphor layer 15, 51 Protective layer 16, 20 Sealing member

Claims (8)

Cutting the sheet having the phosphor layer containing the phosphor by a cutting method in which the phosphor layer does not contact water, and dividing the sheet into a plurality of phosphor-containing members having the phosphor layer;
Installing each of the plurality of phosphor-containing members on a plurality of light emitting elements;
Covering at least the side surfaces of the plurality of light-emitting elements and at least the side surfaces of the plurality of phosphor-containing members with a sealing member, so that the surface of the phosphor layer of the phosphor-containing member is not exposed; and
Cutting the sealing member by a cutting method using water to obtain a plurality of light emitting devices each including the light emitting element, the phosphor-containing member, and the sealing member;
A method for manufacturing a light-emitting device including: At least a portion of the phosphor has a property of reacting with water,
The manufacturing method of the light-emitting device of Claim 1. Cutting the sheet with an ultrasonic cutter,
The manufacturing method of the light-emitting device of Claim 1 or 2. Cutting the sheet so that the arithmetic average roughness Ra of the cut surface is 100 nm or more,
The manufacturing method of the light-emitting device of any one of Claims 1-3. The phosphor-containing member has a laminated structure of the phosphor layer and a protective layer, and is disposed on the light emitting element so that the phosphor layer faces the light emitting element side.
The manufacturing method of the light-emitting device of any one of Claims 1-4. A light emitting element;
A phosphor layer including a phosphor having a property of reacting with water on the light emitting element;
A protective layer on the phosphor layer;
A sealing member covering side surfaces of the light emitting element, the phosphor layer, and the protective layer;
Have
The light emitting device, wherein the phosphor layer has a tapered shape in which a width in at least a lateral direction increases from the light emitting element side toward the opposite side. The arithmetic average roughness Ra of the side surface of the phosphor layer is 100 nm or more,
The light emitting device according to claim 6. The phosphor layer and the protective layer have a tapered shape in which a width in at least a short direction increases from the light emitting element side toward the opposite side,
The light emitting device according to claim 6 or 7.