JP2021064698A - Light-emitting device and method for manufacturing the same - Google Patents

Abstract

To provide a method for manufacturing a light-emitting device capable of simply forming a reflection wall of a double structure whose inside is a white wall and outside is a black wall.SOLUTION: A first groove 20 is formed by half dicing. A depth of the first groove 20 may be such a depth as to penetrate through a sealing resin 13 and not to penetrate through a substrate 10. Subsequently, a white resin is injected to the first groove 20 to be embedded in the first groove 20, and is cured so that a white wall 15 is formed. Subsequently, a second groove 21 is formed by half dicing. A width of the second groove 21 is made narrower than a width of the first groove 20, and a center in a width direction of the second groove 21 is set to coincide with a dividing line L. A depth of the second groove 21 is set at such a depth as to penetrate through the white wall 15 and not to penetrate through the substrate 10. Subsequently, a black resin is injected to the second groove 21 to be embedded in the second groove 21, and is cured so that a black wall 16 is formed. Subsequently, dicing is performed, and it is separated into individual light-emitting devices.SELECTED DRAWING: Figure 3

Description

The present invention relates to a light emitting device provided with a reflective wall surrounding the light emitting element. It also relates to the manufacturing method thereof.

A light emitting device provided with a reflecting wall surrounding the light emitting element is widely known. As a method for manufacturing a reflective wall, there is a method described in Patent Document 1. In Patent Document 1, after the light emitting element mounted on the substrate is sealed with resin, a groove is formed at a position surrounding the light emitting element by half dicing, and the groove is filled with white resin to fill the reflection wall. Is described to form.

Further, Patent Documents 2 and 3 show a light emitting device having a reflective wall having a double structure of a white resin on the inside and a black resin on the outside. With such a double structure, light leakage is suppressed.

Japanese Unexamined Patent Publication No. 2018-22758 JP-A-2015-176946 Japanese Unexamined Patent Publication No. 2012-216596

However, the method of Patent Document 1 has a problem that light leaks from the reflection wall, and has a problem that the luminous flux is lowered and the contrast is lowered. Further, a method for easily forming a reflective wall having a double structure as in Patent Documents 2 and 3 has not been established.

Therefore, an object of the present invention is to provide a method for manufacturing a light emitting device capable of easily forming a reflective wall having a double structure with a white wall on the inside and a black wall on the outside.

The present invention is divided into a mounting step of mounting a light emitting element at a predetermined position on the substrate surface, a sealing step of providing a sealing resin on the substrate and the light emitting element and sealing the light emitting element, and each light emitting device. The first groove is formed by half-dying along the planned division line, and the depth of the first groove is set to a depth that penetrates the sealing resin and does not penetrate the substrate. A 1-groove forming step, a white wall forming step of injecting white resin into the 1st groove to fill the 1st groove, and curing the white resin to form a white wall, and a half-dying along the planned division line are performed. Two grooves are formed, the width of the second groove is narrower than the width of the first groove, and the depth of the second groove is set to a depth that penetrates the white wall and does not penetrate the substrate, whereby the white wall is formed. A second groove forming step of dividing the parts on the left and right sides of the planned division line, and a black wall forming step of injecting black resin into the second groove to fill the second groove and curing the black resin to form a black wall. A method for manufacturing a light emitting device, which comprises a dividing step of diving along a scheduled line and dividing a black wall and a substrate on the left and right sides of the scheduled line.

Further, in the present invention, there may be further a polishing step of making the upper surface of the sealing resin, the upper surface of the white wall, and the upper surface of the black wall flush by polishing after the black wall forming step and before the dividing step.

Further, in the present invention, the white resin and the black resin may be made of the same base material resin.

Further, the present invention is provided so as to fill the inside surrounded by the substrate, the light emitting element provided on the surface of the substrate, the reflective wall provided at the end of the substrate, and the substrate and the reflective wall. In a light emitting device having a sealing resin for sealing a light emitting element, the reflective wall has a double structure of a white wall made of white resin on the inside and a black wall made of black resin on the outside, and the substrate has an end portion. The stepped portion has a stepped portion, and the stepped portion has a two-step step structure that descends from the inside to the outside, and is a surface that is one step lower than the substrate surface, that is, a first step surface and a first step surface. It has a second step surface which is one step lower than the step surface, a white wall is provided on the first step surface, and a black wall is provided on the second step surface. The stepped surface and the second stepped surface are light emitting devices having an arithmetic mean roughness larger than that of the substrate surface.

According to the present invention, it is possible to easily form a reflective wall having a double structure with a white resin on the inside and a black resin on the outside. In addition, the reflective wall can be prevented from peeling off from the substrate.

The figure which showed the structure of the light emitting device of Example 1. FIG. The figure which showed the manufacturing process of the light emitting device of Example 1. The figure which showed the manufacturing process of the light emitting device of Example 1.

Hereinafter, specific examples of the present invention will be described with reference to the drawings, but the present invention is not limited to the examples.

FIG. 1 is a diagram showing a configuration of a light emitting device according to the first embodiment. As shown in FIG. 1, the light emitting device of the first embodiment includes a substrate 10, a light emitting element 11, a reflective wall 12, and a sealing resin 13.

The substrate 10 is a rectangular plate-shaped member. The material of the substrate 10 is ceramic, glass, glass epoxy resin, or the like. A wiring pattern (not shown) is formed on the surface 10a of the substrate 10. Further, an electrode pattern (not shown) for connecting to an external electric circuit is formed on the back surface 10b of the substrate 10. The wiring pattern on the front surface side and the electrode pattern on the back surface side are connected to each other through holes (not shown) formed in the substrate 10.

A stepped portion 14 is provided at the end of the substrate 10. The step portion 14 has a two-step step structure that descends from the inside to the outside of the light emitting device. The surface that is one step lower than the substrate 10 surface 10a due to the step portion 14 is referred to as the first step surface 14a, and the surface that is one step lower than the first step surface 14a is referred to as the second step surface 14b. The first step surface 14a and the second step surface 14b are substantially parallel to the substrate 10 surface 10a, and the second step surface 14b is continuous with the side surface of the substrate 10. The first step surface 14a and the second step surface 14b have a larger arithmetic mean roughness than the substrate 10 surface 10a.

The light emitting element 11 is mounted on the surface 10a of the substrate 10, and the wiring pattern of the surface 10a of the substrate 10 and the electrodes of the light emitting element 11 are connected by wires, solder, bumps, or the like. The light emitting element 11 may be of any semiconductor material and any structure, and the light emitting color may be limited. Further, the number of light emitting elements 11 does not have to be one, and a plurality of light emitting elements 11 may be mounted on the surface 10a of the substrate 10. For example, a blue light emitting light emitting element 11, a green light emitting light emitting element 11, and a red light emitting light emitting element 11 may be set as one set, and one set or a plurality of sets thereof may be mounted. By controlling each output of blue, green, and red, it is possible to realize a light emitting device capable of emitting an arbitrary light emitting color. Further, electronic components other than the light emitting element 11 may be mounted on the surface of the substrate 10. For example, the drive circuit of the light emitting element 11, the temperature protection element, and the like may be mounted on the surface 10a of the substrate 10 together with the light emitting element 11.

The reflective wall 12 is provided in a wall shape on the stepped portion 14 of the substrate 10. The reflection wall 12 has a double structure, and the inside of the light emitting device is a white white wall 15 and the outside is a black black wall 16. The white wall 15 and the black wall 16 are joined. The white wall 15 and the black wall 16 are both upright plate-shaped (wall-shaped).

The white wall 15 is provided on the first step surface 14a of the step portion 14. The first step surface 14a is rough and has fine irregularities, and since the white wall 15 is included in the irregularities, it is difficult for the white wall 15 to peel off from the substrate 10 due to the anchor effect.

The white wall 15 is made of a white resin obtained by mixing a resin such as a silicone resin, an epoxy resin, or an acrylic resin with _{a light reflecting material such as particles of TiO 2} , ZrO ₂ , Al ₂ O ₃ , or SiO _2. The white wall 15 reflects the light radiated laterally from the light emitting element 11 to improve the output of the light emitting device. In the present invention, "white" means that the color has a sufficiently high reflectance of light from the light emitting element 11, and for example, the reflectance is 80% or more.

The black wall 16 is located in contact with the outside of the white wall 15 and is provided on the surface of the second step surface 14b of the step portions 14. Further, the upper surface of the black wall 16 is flush with the upper surface of the white wall 15, and the outer side surface of the black wall 16 is flush with the side surface of the substrate 10. The second step surface 14b is rough and has fine irregularities, and since the black wall 16 has entered the irregularities, it is difficult for the black wall 16 to peel off from the substrate 10 due to the anchor effect.

The black wall 16 is made of a black resin obtained by mixing a resin such as silicone with a light absorbing material such as carbon black and carbon nanotubes. From the viewpoint of ease of production and cost reduction, it is preferable that the base resin is the same material for the white wall 15 and the black wall 16. In the present invention, "black" means a color having a sufficiently high absorption rate of light from the light emitting element 11, for example, an absorption rate of 80% or more.

The reason for providing the black wall 16 is as follows. Most of the light radiated from the light emitting element 11 to the side is reflected by the white wall 15, but a part of the light is transmitted through the white wall 15. The light leaking from the side of such a light emitting device lowers the luminous flux of the light emitting device and lowers the contrast. Therefore, by absorbing the light transmitted through the white wall 15 by the black wall 16, leakage of light from the side is suppressed, and the luminous flux and the contrast are improved. In particular, since the black wall 16 completely covers the outer side surface of the white wall 15, light leakage can be further suppressed.

Further, since the white wall 15 is provided on the first step surface 14a and the black wall 16 is provided on the second step surface 14b, the lower surface of the black wall 16 is lower than the lower surface of the white wall 15. Therefore, the light transmitted obliquely downward through the white wall 15 can also be absorbed by the black wall 16, and the leakage of light can be further suppressed.

The height H1 from the back surface 10b of the substrate 10 to the surface 14a of the first step (the lower surface of the white wall 15) is preferably 0.3 to 0.7 times the thickness H0 of the substrate 10. The reason will be described in the manufacturing process described later.

The height H2 from the back surface 10b of the substrate 10 to the surface 14b of the second step (the lower surface of the black wall 16) is preferably 0.4 to 0.7 times that of H1. Within this range, leakage of light that passes diagonally downward through the white wall 15 can be further suppressed.

The thickness of the white wall 15 may be a range in which the reflectance of the light from the light emitting element 11 is sufficiently high and the transmittance can be sufficiently reduced. For example, the thickness may be set so that the reflectance of light vertically incident on the white wall 15 is 80% or more and the transmittance is 10% or less.

The thickness of the black wall 16 may be a range as long as the absorption rate of the light transmitted through the white wall 15 is high and the transmittance can be sufficiently reduced. For example, the thickness may be set so that the absorption rate of light vertically incident on the black wall 16 is 80% or more and the transmittance is 10% or less.

The sealing resin 13 is provided so as to fill the inside surrounded by the surface 10a of the substrate 10 and the reflective wall 12, and the thickness thereof is uniform. The light emitting element 11 is sealed by the sealing resin 13. The surface of the sealing resin 13 is flush with the upper surface of the reflective wall 12. Therefore, the light emitting device of the first embodiment has a rectangular parallelepiped shape as a whole.

The material of the sealing resin 13 is an arbitrary resin material capable of transmitting light radiated from the light emitting element 11, such as a silicone resin or an epoxy resin. Any material such as a light diffusing material, a phosphor, and a heat diffusing material may be added to the sealing resin 13.

As described above, in the light emitting device of the first embodiment, the adhesion between the reflective wall 12 and the substrate 10 is improved by the anchor effect, and it is suppressed that the reflective wall 12 is peeled off from the substrate 10 due to the application of stress. .. Further, since the entire outer side surface of the white wall 15 made of white resin is covered with the black wall 16 made of black resin and the lower surface of the black wall 16 is lower than the lower surface of the white wall, the light from the reflection wall 12 can be received. Leakage is suppressed and the luminous flux of the light emitting device is improved.

Next, the method of manufacturing the light emitting device of the first embodiment will be described with reference to FIGS. 2 and 3.

First, the light emitting element 11 is mounted at a predetermined position on the surface 10a of the substrate 10. Next, the sealing resin 13 is applied to the surface 10a of the substrate 10 and the light emitting element 11 to a uniform thickness to seal the light emitting element 11, and the sealing resin 13 is cured by heat treatment (FIG. 2 (FIG. 2). a) See). As the mounting method of the light emitting element 11, any method can be adopted depending on the structure of the light emitting element 11.

Next, half dicing is performed from the surface side of the sealing resin 13 along the line (scheduled division line L) scheduled to be divided for each light emitting device in the subsequent process to form the first groove 20 (FIG. 2). (B)). The corners of the first groove 20 may be rounded. The planned division line L has a grid pattern in a plan view. By this half dicing, fine irregularities are formed on the bottom surface of the first groove 20, and the surface is rougher than the surface 10a of the substrate 10. The bottom surface of the first groove 20 is the first step surface 14a of the step portion 14.

The width of the first groove 20 is set to a width that is the sum of twice the width of the reflective wall 12 and the dicing allowance for the subsequent element division, and the center of the first groove 20 in the width direction is the planned division line L. Set to match.

The depth of the first groove 20 may be deeper than penetrating the sealing resin 13 and reaching the surface 10a of the substrate 10 and not penetrating the substrate 10. For example, the depth may be set so that the height H1 from the back surface 10b of the substrate 10 to the bottom surface of the first groove 20 is 0.3 to 0.7 times the thickness H0 of the substrate 10. Within this range, the sealing resin 13 can be reliably penetrated even if there is an error in the depth of the half dicing, and the substrate 10 can be prevented from penetrating. In addition, it is possible to prevent the substrate 10 from becoming thin and bending, bending, or cracking.

Next, a white resin is injected into the first groove 20 to fill the first groove 20. The white resin may protrude from the first groove 20. Here, since the bottom surface of the first groove 20 is formed with fine irregularities by half dicing, the white resin penetrates into the fine irregularities. Then, the white resin is cured to form the white wall 15 (see FIG. 2C). Since the white resin is cured in a state where it has entered the fine irregularities on the bottom surface of the first groove 20, the white wall 15 is difficult to peel off from the substrate 10 due to the anchor effect.

Next, half dicing is performed from the upper surface side of the white wall 15 along the planned division line L to form the second groove 21 (see FIG. 3A). The corners of the second groove 21 may be rounded. By this half dicing, fine irregularities are formed on the bottom surface of the second groove 21, and the surface is rougher than the surface 10a of the substrate 10. The bottom surface of the second groove 21 is the second step surface 14b of the step portion 14.

The width of the second groove 21 is made narrower than the width of the first groove 20, and the center of the second groove 21 in the width direction is set so as to coincide with the planned division line L. The width of the second groove 21 is the sum of twice the width of the black wall 16 and the dicing allowance for the subsequent element division.

The depth of the second groove 21 is set to be deeper than the first groove 20 so as to penetrate the white wall 15 and not to penetrate the substrate 10.

By setting the width and depth of the second groove 21 in this way, the white wall 15 is divided into the left and right of the scheduled division line L, and the white wall 15 on one light emitting device side and the other light emitting device side adjacent thereto are divided. It is divided into white walls 15. Here, the height H2 from the back surface 10b of the substrate 10 to the bottom surface of the second groove 21 is 0.4 to 0.7 times the height H1 from the back surface 10b of the substrate 10 to the bottom surface of the first groove 20. It is good to set the depth. Even if there is an error in the depth of the half dicing, the white wall 15 can be reliably penetrated, and the substrate 10 can be prevented from penetrating. In addition, leakage of light that passes diagonally downward through the white wall 15 can be further suppressed.

Next, black resin is injected into the second groove 21 to fill the second groove 21. The black resin may protrude from the second groove 21. Here, since the bottom surface of the second groove 21 is formed with fine irregularities by half dicing, the black resin enters the fine irregularities. Then, the black resin is cured to form the black wall 16 (see FIG. 3B). Since the black resin is cured in a state where it has entered the fine irregularities on the bottom surface of the second groove 21, the black wall 16 is difficult to peel off from the substrate 10 due to the anchor effect. Further, since the black wall 16 is formed by injecting black resin into the second groove 21, the black resin can contact and cover the entire surface of the white wall 15 exposed on the side surface of the first groove 20. Therefore, the light that passes through the white wall 15 and leaks can be effectively absorbed by the black wall 16. Further, since the second groove 21 is deeper than the first groove 20, the lower surface of the black wall 16 is lower than the lower surface of the white wall 15. Therefore, the light transmitted obliquely downward through the white wall 15 can also be absorbed by the black wall 16, and the leakage of light can be further suppressed.

Next, the surface of the sealing resin 13, the surface of the white wall 15, and the surface of the black wall 16 are polished so that they are flush with each other, and the height of the light emitting device (distance from the back surface of the substrate 10 to the surface of the sealing resin 13) is adjusted. Adjust (see FIG. 3 (c)). The polishing method is arbitrary, and mechanical polishing or chemical mechanical polishing can be used.

Next, dicing is performed along the scheduled division line L. The black wall 16 and the substrate 10 are divided into the left and right of the scheduled division line L, and are divided into the black wall 16 and the substrate 10 on one light emitting device side and the black wall 16 and the substrate 10 of the other light emitting device adjacent thereto. As a result, it is divided into individual light emitting devices (see FIG. 3D). As described above, the light emitting device of Example 1 is manufactured.

As described above, according to the method for manufacturing the light emitting device of the first embodiment, the reflective wall 12 having a double structure with a white wall 15 on the inside and a black wall 16 on the outside can be easily manufactured. In addition, it is possible to prevent the reflective wall 12 from peeling off from the substrate 10.

The light emitting device of the present invention can be used as various light sources.

10: Substrate 11: Light emitting element 12: Reflective wall 13: Encapsulating resin 14: Step portion 14a: First step surface 14b: Second step surface 15: White wall 16: Black wall 20: First groove 21: Second groove

Claims (6)

The mounting process of mounting the light emitting element at a predetermined position on the substrate surface,
A sealing step of providing a sealing resin on the substrate and the light emitting element and sealing the light emitting element.
Half dicing is performed along the planned division line for each light emitting device to form the first groove, and the depth of the first groove penetrates the sealing resin and the substrate. The first groove forming step of setting the depth so as not to penetrate the
A white wall forming step of injecting a white resin into the first groove to fill the first groove and curing the white resin to form a white wall.
A second groove is formed by half dicing along the planned division line, the width of the second groove is narrower than the width of the first groove, and the depth of the second groove is the white wall. A second groove forming step of dividing the white wall on the left and right sides of the planned division line by setting a depth that penetrates the substrate and does not penetrate the substrate.
A black wall forming step of injecting black resin into the second groove to fill the second groove and curing the black resin to form a black wall.
A division step of dicing along the planned division line and dividing the black wall and the substrate on the left and right sides of the planned division line.
A method for manufacturing a light emitting device, which comprises. The first aspect of claim 1, further comprising a polishing step of making the upper surface of the sealing resin, the upper surface of the white wall, and the upper surface of the black wall flush with each other by polishing after the black wall forming step and before the dividing step. How to manufacture a light emitting device. The method for manufacturing a light emitting device according to claim 1 or 2, wherein the white resin and the black resin are made of the same base material resin. The light emitting device is provided so as to fill the inside surrounded by the substrate, the light emitting element provided on the surface of the substrate, the reflective wall provided at the end of the substrate, and the substrate and the reflective wall. In a light emitting device having a sealing resin for sealing an element,
The reflective wall has a double structure of a white wall made of white resin on the inside and a black wall made of black resin on the outside.
The substrate has a stepped portion at the end and has a stepped portion.
The step portion has a two-step structure that descends from the inside to the outside, and is a surface that is one step lower than the substrate surface and a first step surface, and further than the first step surface. It has a second stepped surface, which is one step lower.
The white wall is provided on the surface of the first step, and is provided.
The black wall is provided on the surface of the second step.
The first step surface and the second step surface have a larger arithmetic mean roughness than the substrate surface.
A light emitting device characterized in that. The light emitting device according to claim 4, wherein the upper surface of the sealing resin, the upper surface of the white wall, and the upper surface of the black wall are flush with each other. The light emitting device according to claim 4 or 5, wherein the white resin and the black resin are made of the same base material resin.

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