JP6971705B2 - Manufacturing method of resin molded body and light emitting device and light emitting device - Google Patents

Description

The present invention relates to a light emitting device including, for example, a light emitting element such as a light emitting diode and a resin molded body that seals the light emitting element, and a method for manufacturing the resin molded body and the light emitting device.

Conventionally, a light emitting device including a light emitting element and a resin body for sealing the light emitting element has been known. For example, the resin body acts as a lens that collects, diffuses, or guides the emitted light from the light emitting element. Patent Document 1 discloses a method for manufacturing an optical semiconductor device, which comprises a step of crimping a substrate on which an LED chip is mounted in a resin mold recess and heating the substrate to cure the resin.

Japanese Unexamined Patent Publication No. 2013-105817

For example, when the sealing resin is used as a lens of a light emitting device, the resin material is formed into a lens shape. Further, the resin material can be molded into various shapes, such as when the optical element such as a light guide material is formed of a resin, not limited to the light emitting device. Here, when molding a resin, it is preferable that a resin molded body having a desired shape can be manufactured with a high degree of freedom and a simple process. Further, it is preferable that the light emitting device having a lens made of a sealing resin has a lens having a shape corresponding to various uses such as light collecting use, diffusion use, and light guide use.

Further, not only when used for condensing applications such as lenses, the sealing resin does not deteriorate its sealing function for a long period of time, and thereby the function of the device (for example, shipping) for a long period of time. It is preferable to keep the optical characteristics of the light emitting device at the time.

The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing a resin molded product capable of easily producing resin molded products having various shapes. Another object of the present invention is to provide a light emitting device having a lens having a shape highly compatible with various uses and a method for manufacturing the same. Another object of the present invention is to provide a high quality and long life light emitting device in which deterioration of the sealing resin is suppressed.

The method for manufacturing a light emitting device according to the present invention includes a step of mounting a light emitting element on a mounting substrate, a step of applying a thermosetting resin on the mounting substrate so as to embed the light emitting element, and plasma irradiation of the thermosetting resin. Alternatively, it includes a step of irradiating with infrared rays to cure only the surface portion of the thermosetting resin and a step of heating and curing the thermosetting resin having the cured surface portion to form a resin molded body. It is a feature.

Further, in the method for manufacturing a resin molded body according to the present invention, a step of applying a thermosetting resin on a substrate and plasma irradiation or infrared irradiation of the thermosetting resin are performed to cure only the surface portion of the thermosetting resin. It is characterized by including a step and a step of heating and curing a thermosetting resin whose surface portion is cured.

Further, the light emitting device according to the present invention is composed of a mounting substrate, a light emitting element mounted on the mounting substrate, and a thermosetting resin formed on the mounting substrate so as to embed the light emitting element, and has surfaces having different hardness. It is characterized by having a lens having a region and an internal region.

Further, the light emitting device according to the present invention comprises a mounting substrate, a light emitting element formed on the mounting substrate, and a resin molded body formed on the mounting substrate so as to embed the light emitting element, and has surface regions having different hardness from each other. It is characterized by having a sealing resin having an internal region and having a wavy structure including a plurality of irregularities on the externally exposed surface of the surface region.

It is sectional drawing of the light emitting device which concerns on Example 1. FIG. It is a top view of the light emitting device which concerns on Example 1. FIG. It is a figure which shows the manufacturing method of the light emitting device which concerns on Example 1. FIG. It is a figure which shows the manufacturing method of the light emitting device which concerns on Example 1. FIG. It is a figure which shows the manufacturing method of the light emitting device which concerns on Example 1. FIG. It is a figure which shows the manufacturing method of the light emitting device which concerns on Example 1. FIG. FIG. 3 is an enlarged cross-sectional view of the surface of a lens in the light emitting device according to the first embodiment. It is sectional drawing of the light emitting device which concerns on modification 1 of Example 1. FIG. It is sectional drawing of the light emitting device which concerns on modification 2 of Example 1. FIG. It is sectional drawing of the light emitting device which concerns on Example 2. FIG. It is a top view of the light emitting device which concerns on Example 2. FIG. It is sectional drawing of the light emitting device which concerns on modification 1 of Example 2. FIG. It is sectional drawing of the light emitting device which concerns on modification 2 of Example 2. FIG. It is sectional drawing of the light emitting device which concerns on Example 3. FIG. It is sectional drawing of the light emitting device which concerns on Example 4. FIG. It is a top view of the light emitting device which concerns on Example 4. FIG. It is sectional drawing of the light emitting device which concerns on Example 5. FIG. It is a top view of the light emitting device which concerns on Example 5. FIG. It is an image of the upper surface of the sealing resin in the light emitting device which concerns on Example 5. FIG. It is a figure which shows the optical characteristic of the light emitting device which concerns on Example 5. FIG. It is a figure which shows the optical characteristic of the light emitting device which concerns on a comparative example.

Hereinafter, examples of the present invention will be described in detail.

FIG. 1A is a cross-sectional view of the light emitting device 10 according to the first embodiment. Further, FIG. 1B is a schematic top view of the light emitting device 10. Note that FIG. 1A is a cross-sectional view taken along the line VV of FIG. 1B. The configuration of the light emitting device 10 will be described with reference to FIGS. 1A and 1B. The light emitting device 10 includes a mounting substrate 11, a light emitting element 12 mounted on the mounting substrate 11, and a lens 13 made of a resin molded body in which the light emitting element 12 is embedded and sealed.

For example, the mounting substrate 11 has a mounting surface (mounting surface) provided with metal wiring (not shown) for supplying power to the light emitting element 12. The light emitting element 12 is fixed on the mounting surface and is connected to the wiring by, for example, wire bonding.

The light emitting element 12 is a semiconductor light emitting element such as a light emitting diode. In this embodiment, the surface of the light emitting element 12 other than the surface (lower surface) facing the mounting substrate 11, for example, the upper surface and the side surface of the light emitting element 12 function as the light extraction surface of the light emitting element 12.

The lens 13 is made of a thermosetting resin made of a polymer material such as an epoxy resin, an acrylic resin and a silicone resin. Further, the lens 13 is made of a resin molded body obtained by molding and curing a thermosetting resin. The lens 13 has translucency with respect to the light emitted from the light emitting element 12. In this embodiment, the lens 13 is transparent.

The lens 13 functions as a lens that collects, diffuses, or guides the light emitted from the light emitting element 12. For example, in this embodiment, the lens 13 has a hemispherical surface shape and functions as a light diffusing lens that diffuses the light emitted from the light emitting element 12.

Further, as shown in FIG. 1A, the lens 13 has a surface region 13A and an internal region 13B having different hardnesses from each other. In this embodiment, the surface region 13A has a higher hardness than the internal region 13B. The surface region 13A is a region constituting the outermost surface of the lens 13. The internal region 13B is a region provided inside the surface region 13A of the lens 13. In this embodiment, the internal region 13B embeds the light emitting element 12 and seals the light emitting element 12. The surface region 13A is provided so as to cover the internal region 13B.

Further, in this embodiment, as shown in FIG. 1B, the mounting substrate 11 has a rectangular shape on the mounting surface of the light emitting element 12. Further, the light emitting element 12 has a rectangular upper surface shape. Further, as shown in FIGS. 1A and 1B, the lens 13 has a cylindrical base portion BS formed on the mounting substrate 11 and a hemispherical lens portion LZ formed on the base portion BS. Further, the base portion BS and the lens portion LZ are integrally formed.

2A to 2D are schematic cross-sectional views showing a manufacturing process of the light emitting device 10, respectively. A method for manufacturing the light emitting device 10 will be described with reference to FIGS. 2A to 2D.

[Mounting of light emitting element 12]
FIG. 2A is a diagram showing a mounting substrate 11 on which the light emitting element 12 is mounted. First, the light emitting element 12 is mounted on the mounting substrate 11 (step 1). In this embodiment, the light emitting element 12 is bonded to the mounting substrate 11 to which wiring or the like is provided, and the light emitting element 12 and the wiring are connected by wire bonding.

[Application of thermosetting resin 13P]
FIG. 2B is a diagram showing a mounting substrate 11 coated with a thermosetting resin 13P. The thermosetting resin 13P is applied onto the mounting substrate 11 so as to embed the light emitting element 12 on the mounting substrate 11 on which the light emitting element 12 is mounted (step 2). In this example, a silicone resin was used as the thermosetting resin 13P. Further, the nozzle of the coating device was arranged on the light emitting element 12, and a predetermined amount of the thermosetting resin 13P was potted. Further, in this example, the viscosity and the coating amount of the thermosetting resin 13P were adjusted so as to have a lens shape after coating.

[Curing the surface portion 13P1 of the thermosetting resin 13P]
FIG. 2C is a diagram showing a thermosetting resin 13P on which the surface portion 13P1 is cured. After applying the thermosetting resin 13P, plasma irradiation or infrared irradiation is performed on the thermosetting resin 13P (step 3). As a result, only the surface portion (the portion not in contact with the mounting substrate 11) 13P1 of the thermosetting resin 13P is cured.

For example, as the plasma to be irradiated, a plasma of oxygen or argon gas can be used. Further, for example, when a silicone resin is used as the thermosetting resin 13P, only the surface portion 13P1 of the thermosetting resin 13P can be cured by infrared irradiation.

By this step, only the surface portion 13P1 of the thermosetting resin 13P is cured, and a surface hardening region to be the surface region 13A of the lens 13 is formed. Here, the thermosetting resin 13P other than the surface portion 13P1 is in an uncured state. However, by curing the surface portion 13P1, the shape (outer shape) immediately after the application of the thermosetting resin 13P is maintained even after this step.

[Curing of thermosetting resin 13P]
FIG. 2D is a diagram showing a lens 13 formed by curing the thermosetting resin 13P. The thermosetting resin 13P on which the surface portion 13P1 is cured is heated and cured (step 4). In this embodiment, the mounting substrate 11 containing the thermosetting resin 13P was heated to 150 ° C. by a heating device such as a heater. As a result, the entire thermosetting resin 13P is cured, and a resin molded body that functions as the lens 13 is formed.

After this step, both the already cured surface portion 13P1 and the internal portion of the uncured thermosetting resin 13P are heated and cured. The surface portion 13P1 which is a cured portion of the thermosetting resin 13P becomes the surface region 13A of the lens 13, and the uncured internal portion becomes the internal region 13B of the lens 13. In other words, the surface portion 13A of the lens 13 is cured through a two-step (steps 3 and 4) curing step. On the other hand, the internal region 13B of the lens 13 is cured through a one-step (step 4) curing step.

As described above, the method for manufacturing the light emitting device 10 includes a step (step 2) of applying the thermosetting resin 13P on the mounting substrate 11 so as to embed the light emitting element 12 on the mounting substrate 11, and a thermosetting resin 13P. (Step 3), in which only the surface portion 13P1 of the thermosetting resin 13P is cured by irradiating with plasma or infrared rays, and a step (step 3) in which the thermosetting resin 13P is heated and cured to form a resin molded body. 4) and is included.

As a result, the shape immediately after the application of the thermosetting resin 13P (immediately after the step 2) is maintained until after the curing. That is, if the thermosetting resin 13P is applied so as to have a desired lens shape, the lens 13 having that shape can be formed. Therefore, by applying the thermosetting resin so as to have various shapes, it is possible to easily form a lens having a shape highly compatible with various uses.

If the curing step of the surface portion 13P1 by plasma treatment or the like is omitted, it becomes difficult to form a resin molded body having a desired shape. Specifically, when the resin material is heated, the viscosity is once lowered and then curing is started. Therefore, the shape immediately after application collapses before curing, and the shape is cured (molded) in an unintended shape.

On the other hand, in this embodiment, by curing the surface of the thermosetting resin 13P, the shape immediately after coating can be maintained until the start of curing. Therefore, the lens 13 having a desired shape can be molded. Moreover, since it is not necessary to use a molding die, molding can be performed at low cost.

In this embodiment, the case where the light emitting device 10 is manufactured by the above step has been described. However, the mounting step of the light emitting element 12 may be omitted. That is, a thermosetting resin 13P is applied onto a substrate (for example, a substrate such as a mounting substrate 11) so as to have a desired shape (step 2A), a surface curing step by plasma treatment (step 3), and a subsequent overall curing step. By performing (step 4), various resin molded bodies can be easily manufactured. That is, the present invention can also be implemented as a method for manufacturing a resin molded product.

Further, the lens 13 (or resin molded body) of the light emitting device 10 manufactured through the above steps has a surface region 13A and an internal region 13B having different hardnesses from each other. In this embodiment, the case where the surface region 13A has a higher hardness than the internal region 13B has been described. However, depending on the material and treatment conditions, the internal region 13A may have a higher hardness than the surface region 13A.

That is, in the step of curing the thermosetting resin 13P (step 4), the surface portion 13P1 of the thermosetting resin 13P is cured to a hardness different from that of other portions. The inventors of the present application have confirmed that the surface region 13A and the internal region 13B of the lens 13 (resin molded body) can be distinguished by at least analyzing the hardness.

FIG. 3 is a partially enlarged cross-sectional view showing an enlarged portion of the surface region 13A of the lens 13. It should be noted that FIG. 3 is an enlarged view showing a portion surrounded by a broken line in FIG. 1A. As shown in FIG. 3, the lens 13 has a roughened lens surface 13S having a plurality of fine irregularities. It is understood that this is due to plasma treatment or infrared irradiation of the thermosetting resin 13P. That is, the step of curing the surface portion 13P1 of the thermosetting resin 13P includes a step of forming a plurality of irregularities on the surface portion 13P of the thermosetting resin 13P and roughening the surface portion 13P.

In the light emitting device 10, since the lens 13 has the lens surface 13S made of fine irregularities, light is easily emitted from the lens surface 13S. Therefore, the light extraction efficiency of the light emitting device 10 is often improved. Therefore, the lens 13 can collect, diffuse, or guide light with high brightness. The unevenness of the lens surface 13S has a fine size and shape that does not affect the lens action of the lens 13. That is, the unevenness of the lens surface 13S has a size and a shape in which the light emitted from the light emitting element 12 is insensitive.

It should be noted that these fine irregularities are formed not only on the lens surface 13S (hemispherical surface) but also on the entire surface region 13A of the lens 13. Therefore, this fine unevenness also exhibits a high extraction effect with respect to the light emitted from the light emitting element 12 to the mounting substrate 11 in the horizontal direction. Therefore, the light emitting device 10 can output light with high extraction efficiency in all directions on the mounting substrate 11.

In this embodiment, the case where the lens 13 has a spherical lens portion LZ has been described, but the shape of the lens 13 is not limited to this. The lens 13 may have a conical shape. The lens 13 may be configured to collect, diffuse, or guide the light emitted from the light emitting element 12. Further, although the case where the lens 13 has a cylindrical base portion BS has been described, the shape of the base portion BS is not limited to this. Further, the lens 13 does not have to have the base portion BS, and the lens portion LZ may be formed on the mounting substrate 11.

As described above, the light emitting device 10 is composed of a light emitting element 12 mounted on the mounting substrate 11 and a resin molded body formed on the mounting substrate 11 so as to embed the light emitting element 12, and has surface regions having different hardness from each other. It has a lens 13 having a 13A and an internal region 13B. Further, the lens 13 has a roughened lens surface 13S composed of a plurality of irregularities. Therefore, it is possible to provide a light emitting device 10 having a lens 13 having a shape highly compatible with various uses and having a high light extraction efficiency.

FIG. 4A is a cross-sectional view of the light emitting device 10A according to the modified example of the first embodiment. The light emitting device 10A has the same configuration as the light emitting device 10 except for the configuration of the lens 14. The light emitting device 10A has a tip-shaped lens 14. Like the lens 13, the lens 14 has a surface region 14A and an internal region 14B having different hardnesses from each other.

In this modification, the lens 14 includes a columnar base portion BS formed on the mounting substrate 11 and a conical lens portion LZ1 formed on the base portion BS. Further, in this modification, the lens portion LZ1 of the lens 14 has an optical axis AX1 in a direction different from the optical axis AX of the emitted light of the light emitting element 12. That is, the optical axis AX of the light emitting element 12 and the optical axis AX1 of the lens 14 are provided in different directions.

The lens shape of the lens 14 is easily formed, for example, by adjusting the position and the amount of movement of the nozzle at the time of coating the thermosetting resin 13P (see, for example, Step 2 and FIG. 2B). be able to. Further, similarly to the lens 13, by performing surface curing (for example, plasma irradiation) and then performing overall curing (for example, heating with a heater), molding can be easily performed without losing the shape at the time of coating. The optical axis AX of the emitted light of the light emitting element 12 means a straight line extending in a direction perpendicular to the mounting surface of the mounting substrate 11 through the center of the light emitting region of the light emitting element 12.

In this modification, the lens 14 has a tip shape. Therefore, the light distribution control of the emitted light from the light emitting element 12 can be easily performed. For example, the light emitting device 10A can emit light in a desired emission direction while reducing the emission light.

Further, in this modification, the lens 14 is formed so as to have an optical axis AX1 in a direction different from the optical axis AX of the emitted light of the light emitting element 12. Therefore, the configuration is suitable for emitting the emitted light from the light emitting element 12 in a predetermined direction.

FIG. 4B is a cross-sectional view of the light emitting device 10B according to the second modification of the first embodiment. The light emitting device 10B has the same configuration as the light emitting device 10 except for the configuration of the lens 15. In this modification, the light emitting device 10B has a lens 15 having a frustum-shaped base portion BS1. Like the lens 13, the lens 15 has a surface region 15A and an internal region 15B having different hardnesses from each other.

In this modification, the lens 15 has a frustum-shaped base portion BS1 formed on the mounting substrate 11 and tapered toward the mounting substrate 11, and a lens portion LZ formed on the base portion BS1. Have. In this modification, the base portion BS1 has a truncated cone shape, and the lens portion LZ has a hemispherical shape.

More specifically, the base portion BS1 is formed in a frustum shape so that the bottom surface (bottom surface on the small area side) faces the mounting substrate 11 and the top surface (bottom surface on the large area side) faces the lens portion LZ. ing. That is, the base portion BS is formed on the mounting substrate 11 in the shape of a reverse taper. Further, the lens portion LZ is formed in a hemispherical shape on the upper surface of the base portion BS1.

Similar to the lens 13 or 14, the lens 15 can be easily formed by, for example, adjusting the position and the amount of movement of the nozzle when applying the thermosetting resin 13P.

In the case of a shape such as a lens 15 in which the cross-sectional area in the horizontal direction to the mounting substrate 11 increases as the distance from the mounting substrate 11 increases, it may be difficult to mold using a mold. Specifically, if there are restrictions on the shape that can be molded due to the draft and unevenness of the mold, or if the shape of the mold and the molding process are complicated, the molding itself may become difficult. be. However, as in this modification, by curing only the resin surface before heating to determine the outer shape, it can be easily formed into a desired shape.

Further, in this modification, the lens 15 has a frustum-shaped base portion BS1 that tapers toward the mounting substrate 11. The side surface of the base portion BS1 reflects the light emitted from the light emitting element 12 toward the lens portion LZ. Therefore, the light extraction efficiency is improved.

As shown in the above-mentioned Examples and Modifications thereof, even if the lens has a shape that is difficult to use, for example, when a mold is used, the surface portion of the thermosetting resin is cured to determine the shape before the entire curing. By doing so, lens molding can be easily performed. Further, it is possible to provide a light emitting device having a lens having a shape highly compatible with various applications.

FIG. 5A is a cross-sectional view of the light emitting device 20 according to the second embodiment. Further, FIG. 5B is a schematic top view of the light emitting device 20. Note that FIG. 5A is a cross-sectional view taken along the line WW of FIG. 5B. In this embodiment, the light emitting device 20 has the same configuration as the light emitting device 10 except for the configuration of the lens 21.

Like the lens 13, the lens 21 has a surface region 21A and an internal region 21B having different hardnesses from each other. In this embodiment, the lens 21 is composed of a base portion BS and a lens portion LZ2 integrally formed. The base portion BS is formed on the mounting substrate 11, and the lens portion LZ2 is formed on the base portion BS. Further, the lens portion LZ2 has a protruding region PA that protrudes from the base portion BS in the horizontal direction (sideways) to the mounting substrate 11.

In this embodiment, the base portion BS is a columnar portion formed on the mounting substrate 11. The lens portion LZ2 is a spherical portion formed on the base portion BS. Further, the lens portion LZ2 is formed on the base portion BS with a diameter larger than the diameter of the base portion BS (maximum size in the direction horizontal to the mounting substrate 11).

The lens 21 can be easily formed, for example, by adjusting the position and the amount of movement of the nozzle when the thermosetting resin 13P is applied onto the light emitting element 12, as in the process shown in the first embodiment. Can be done.

In this embodiment, the lens portion LZ2 is formed so as to have a protruding region PA protruding from the base portion BS. This improves the light extraction efficiency of the wide-angle component in the light emitting device 20. In addition, the light distribution controllability of the wide-angle component is improved. For example, light can be diffused so as to have a desired luminance and light distribution even for a wide-angle component.

FIG. 6A is a cross-sectional view of the light emitting device 20A according to the first modification of the second embodiment. The light emitting device 20A has the same configuration as the light emitting device 20 except for the configuration of the lens 22. Like the lens 21, the lens 22 has a surface region 22A and an internal region 22B having different hardnesses from each other. Further, the lens 22 has the same configuration as the lens 21 except for the configuration of the base portion BS1.

In this modification, the lens 22 has a frustum-shaped base portion BS1 having a shape tapered toward the mounting substrate 11, and a lens portion LZ2 formed on the base portion BS1. In this modification, the base portion BS1 has a truncated cone shape. The lens portion LZ2 is formed in a spherical shape so as to have a diameter larger than the diameter of the upper surface (bottom surface on the large area side of the truncated cone) of the base portion BS1. This modification corresponds to a configuration in which the base portion BS of the lens 21 is replaced with the base portion BS1 of the lens 15 (modification example 2 of the first embodiment, see FIG. 5B).

In this modification, the base portion BS1 has a frustum shape that tapers toward the mounting substrate 11. Therefore, the light emitted from the light emitting element 12 is likely to be reflected from the side surface of the base portion BS1 toward the lens portion LZ. Therefore, the light extraction efficiency is improved.

FIG. 6B is a cross-sectional view of the light emitting device 20B according to the second modification of the second embodiment. The light emitting device 20B has the same configuration as the light emitting device 20 except for the configuration of the lens 23. The lens 23 has the same configuration as the lens 21 except for the configuration of the lens portion LZ3. The lens 23 has a surface region 23A and an internal region 23B having different hardnesses from each other.

In this modification, the lens 23 has a lens portion LZ3 having an optical axis AX2 in a direction different from the optical axis AX of the emitted light of the light emitting element 12. In this modification, the lens portion LZ3 has a columnar portion extending from the base portion BS in a direction different from the optical axis AX of the light emitting element 12 (direction along the optical axis AX2). A hemispherical portion is formed at the end of the columnar portion.

The lens 23 can be formed, for example, by moving the nozzle in the in-plane direction of the mounting substrate 11 during coating in the step of applying the thermosetting resin 13P.

In this modification, the lens 23 functions as a light guide lens that outputs the light emitted from the light emitting element 12 in a direction inclined from the optical axis AX of the light emitting element 12. Even when molding a lens having a somewhat complicated shape such as the lens 23, the molding can be easily performed only by adjusting the viscosity of the resin material and controlling the coating device. Further, the light emitting device 20C is a light emitting device having a light guide lens having high light extraction efficiency.

As shown in this example and its modification, even if the lens has a shape that is difficult to use, for example, when a mold is used, the surface portion of the thermosetting resin is cured to determine the shape before the entire curing. Therefore, it can be easily molded. Further, it is possible to provide a light emitting device having a lens having a shape highly compatible with various applications.

FIG. 7 is a cross-sectional view of the light emitting device 30 according to the third embodiment. The light emitting device 30 has the same configuration as the light emitting device 10 except for the configuration of the lens 31. Like the lens 13, the lens 31 has a surface region 31A and an internal region 31B having different hardnesses from each other.

The lens 31 has a plurality of (two in this embodiment) lens portions LZ with respect to the light emitting element 12. In this embodiment, the lens 31 has two spherical portions integrally formed on the light extraction surface of the light emitting element 12 as the lens portion LZ.

The lens 31 can be formed, for example, by changing the position of the nozzle on the light emitting element 12 and applying the lens 31 in two steps in the step (step 2) of applying the thermosetting resin 13P.

In the light emitting device 30, the light emitted from the light emitting element 12 is taken out in different directions by each of the two lens portions LZ. That is, the lens 31 has a configuration that separates the emitted light from the light emitting element 12 into a plurality of extracted lights. Therefore, the light emitting device 30 has a configuration suitable for an application in which the light emitted from the plurality of light emitting elements 12 is output to a plurality of output destinations.

As described above, the light emitting device 30 has a lens 31 having a plurality of lens portions LZ (diffusing portion, condensing portion or light guide portion). Therefore, it is possible to provide a light emitting device 30 having a lens 31 having a shape highly compatible with various uses.

FIG. 8A is a cross-sectional view of the light emitting device 40 according to the fourth embodiment. Further, FIG. 8B is a schematic top view of the light emitting device 40. Note that FIG. 8A is a cross-sectional view taken along the line XX of FIG. 8B. The light emitting device 40 has the same configuration as the light emitting device 10 except for the configurations of the light emitting element 41 and the lens 42.

In the light emitting device 40, the light emitting element 41 has a plurality of (three in this embodiment) light emitting segments 41A juxtaposed on the mounting substrate 11. For example, the three light emitting segments 41A each include three light emitting diodes that emit light of different wavelengths (eg, red, green and blue). In this embodiment, the three light emitting segments 41A are arranged in a triangular grid pattern on the mounting substrate 11. In other words, each of the light emitting segments 41A is arranged so as to form the vertices of an equilateral triangle on the mounting substrate 11.

Further, the lens 42 has a lens portion LZ formed on each of the plurality of light emitting segments 41A. In this embodiment, the lens 42 has a spherical portion as a lens portion LZ on each of the light emitting segments 41A. Further, the lens portion LZ of the lens 42 is integrally formed. The lens 42, like the lens 13, has a surface region 42A and an internal region 42B having different hardnesses from each other.

The lens 42 can be formed, for example, by repeating the process of applying the thermosetting resin 13P three times with the nozzles arranged above one light emitting segment 41A, similarly to the lens 31.

In the light emitting device 40, a lens portion LZ is configured for each light emitting segment 41A. The light emitted from one light emitting segment 41A is taken out to the outside through one lens unit LZ. The light emitting device 40 has a configuration suitable for an application such as switching between a light extraction direction and a light extraction timing, for example.

In this embodiment, the case where each of the light emitting segments 41A is arranged in a triangular lattice pattern has been described, but the arrangement configuration of the light emitting segments 41A is not limited to this. For example, each of the light emitting segments 41A may be aligned in a row and arranged in a straight line. Further, the lens portion LZ of the lens 42 may be arranged above each of the light emitting segments 41A (on the optical axis).

As described above, the light emitting device 40 includes a light emitting element 41 having a plurality of light emitting segments 41A juxtaposed on the mounting substrate 11 and a lens 42 having a lens portion LZ formed on each of the plurality of light emitting segments 41A. Have. Therefore, it is possible to provide a light emitting device 40 having a lens 42 having a shape highly compatible with various applications.

In addition, the above-mentioned examples can be combined with each other. For example, any one of the lens portions LZ of the lens 42 of the light emitting device 40 according to the fourth embodiment may have a tip shape like the lens portion LZ1 in the light emitting device 10A according to the modified example 1 of the first embodiment. good.

FIG. 9A is a cross-sectional view of the light emitting device 50 according to the fifth embodiment. FIG. 9B is a schematic top view of the light emitting device 50. 9A is a cross-sectional view taken along the line YY of FIG. 9B. Further, FIG. 9C is an observation image of the sealing resin 53 in the light emitting device 50. The light emitting device 50 will be described with reference to FIGS. 9A to 9C.

The light emitting device 50 is provided in the mounting substrate 51 having the recess 51R, the light emitting element 12 mounted in the recess 51R of the mounting board 51, and the sealing element 12 provided in the recess 51R of the mounting board 51 to seal the light emitting element 12. It has a resin 53 and. In this embodiment, the light emitting element 12 has the same configuration as the light emitting device 10 of the first embodiment.

More specifically, in this embodiment, the mounting substrate 51 has a truncated cone-shaped recess 51R having a bottom surface 51A and a side surface 51B. The light emitting element 12 is mounted on the bottom surface 51A of the recess 51R in the mounting substrate 51. The mounting substrate 51 has a pad electrode and wiring (not shown) connected to the light emitting element 12 on the bottom surface 51A of the recess 51R.

Further, in this embodiment, the sealing resin 53 is provided so as to fill the region (space) in the recess 51R in the recess 51R of the mounting substrate 51. Further, the sealing resin 53 has a surface region 53A and an internal region 53B having different hardnesses from each other. In this embodiment, the sealing resin 53 is made of a resin molded body similar to the lens 13 of the light emitting device 10. Further, the surface region 53A has a higher hardness than the internal region 53B.

In this embodiment, the surface region 53A of the sealing resin 53 is a region of the sealing resin 53 that is exposed to the outside atmosphere. Further, the internal region 53B of the sealing resin 53 is a portion of the sealing resin 53 surrounded by the bottom surface 51A and the side surface 51B of the recess 51R in the mounting substrate 51 and the surface region 53A of the sealing resin 53.

Further, in the present embodiment, the surface region 53A of the sealing resin 53 has a wavy structure including a plurality of unevennesses P1 on the externally exposed surface S1. Further, in this embodiment, the surface region 53A of the sealing resin 53 has a wavy structure including a plurality of irregularities P2 reflecting the irregularities P1 of the external exposed surface S1 at the interface S2 with the inner region 53B. In this embodiment, the surface region 53A of the sealing resin 53 forms a wavy structural layer as a whole.

For example, the light emitting device 50 is a light emitting device except that the light emitting element 12 is mounted in the recess 51R of the mounting substrate 51 having the recess 51R and the thermosetting resin is applied in the recess 51R of the mounting substrate 51. It can be produced through the same steps as in 10.

For example, in this embodiment, the sealing resin 53 was formed by the following steps. First, a thermosetting resin (thermosetting resin similar to the thermosetting resin 13P) is applied to the recess 51R of the mounting substrate 51 on which the light emitting element 12 is mounted, and the recess 51R is filled with the thermosetting resin. Fill (corresponding to step 2 above). Subsequently, the thermosetting resin is irradiated with plasma to cure the surface portion (corresponding to step 3 above). As a result, unevennesses P1 and P2 of the surface region 53A are formed, and a wavy surface-hardened layer is formed.

Here, the mechanism by which the irregularities P1 and P2 are formed will be described. At the time of the plasma irradiation, the resin shrinks due to the decrease in the volume of the resin at the portion irradiated with the plasma, and a wavy uneven surface is formed. Further, this resin shrinkage also occurs up to a certain depth portion where the plasma is irradiated (the plasma particles reach).

Therefore, by plasma irradiation, a wavy surface-hardened layer having irregularities (unevenness P1 and P2) formed on both the outer surface and the inner surface is formed so as to maintain a constant depth (thickness). Further, the unevenness P2 of the interface S2 between the surface region 53A and the internal region 53B is formed in a shape and arrangement that reflects the unevenness P1 of the externally exposed surface S1 of the surface region 53A.

By adjusting the irradiation time and irradiation intensity of the plasma, the depth and size of the unevenness, the depth of the cured portion, and the like can be adjusted. For example, as an example of the depth and size of the unevenness P1, in this embodiment, the arithmetic average roughness Ra of the externally exposed surface S1 is in the range of about 20 μm to 70 μm.

After that, the entire thermosetting resin is cured, including the surface portion that has already been cured, by heating the entire resin using, for example, a heater (corresponding to step 4 above). As a result, the previously cured surface portion becomes the surface region 53A, and the inner portion thereof becomes the internal region 53B. In this way, the sealing resin 53 can be formed.

In this embodiment, the thermosetting resin may be applied so as to fill the inside of the recess 51R (embed the light emitting element 12). For example, the surface portion of the thermosetting resin may have a lens shape or a flat shape before plasma irradiation.

FIG. 9C is an observation image of the upper surface of the light emitting device 50. The left side of the figure is an observation image of the entire upper surface (external exposed surface S1) of the surface region 53A of the sealing resin 53, and the right side is a partially enlarged view thereof. As shown in FIG. 9C, it can be seen that wrinkled (wrinkle-like) unevenness P1 is formed in the surface region 53A.

In this embodiment, the sealing resin 53 has translucency with respect to the light emitted from the light emitting element 12, and is, for example, transparent. That is, the sealing resin 53 is made of a translucent resin molded body. Further, in this embodiment, the mounting substrate 51 has reflectivity to the light emitted from the light emitting element 12, and is made of, for example, a white resin.

Therefore, in this embodiment, a part of the light emitted from the light emitting element 12 is reflected from the bottom surface 51A and the side surface 51B of the recess 51R of the mounting substrate 51 to the outside from the surface region 53A of the sealing resin 53. Taken out. In other words, the sealing resin 53 constitutes a light extraction unit in the light emitting device 50. Further, the surface region 53A of the sealing resin 53 functions as a light extraction surface in the light emitting device 50.

The sealing resin 53 may contain phosphor particles. When the sealing resin 53 contains phosphor particles, the sealing resin 53 functions as a wavelength converter that performs wavelength conversion with respect to the light emitted from the light emitting element 12. For example, when the sealing resin 53 contains phosphor particles, light of various wavelengths can be extracted.

FIG. 10A is a diagram showing the optical characteristics of the light emitting device 50. FIG. 10A measures the light intensity for each angle when the front position of the light emitting element 12 in the light emitting device 50 is 0 °, and the measurement result is the relative intensity when the light intensity at the 0 ° is 100. It is a figure shown by. Further, FIG. 10B is a diagram showing the results of measuring the optical characteristics of the light emitting device 100 according to the comparative example under the same conditions as the light emitting device 50.

As the light emitting device 100 of the comparative example, a light emitting device manufactured through the same steps except that the entire thermosetting resin was cured with a heater to form a sealing resin without plasma irradiation was prepared. bottom. In the light emitting device 100, the surface of the sealing resin was flat.

As shown in FIGS. 10A and 10B, it can be seen that the light emitting device 50 has the same optical characteristics as the light emitting device 100. In other words, it can be seen that even if the sealing resin 53 has the wavy unevenness P1 on the surface region 53A (light extraction surface), the optical characteristics are hardly affected.

Further, the inventor of the present application has confirmed that the sealing resin 53 has the unevenness P1 on the surface region 53A, so that the deterioration of the sealing resin 53 of the light emitting device 50 is suppressed. Specifically, the inventor of the present application conducted a durability test on the light emitting device 50 (Example) and the light emitting device 100 (Comparative Example) for investigating the state and optical characteristics of the sealing resin. As a result, it was confirmed that the light emitting device 50 maintained the shape of the sealing resin longer than the light emitting device 100 and maintained the optical characteristics for a long time.

Specifically, first, light emitting devices 50 and 100 having a structure in which the sealing resin does not contain a fluorescent substance are prepared, and a heating durability test is conducted in which the shape change of the sealing resin is investigated while these are heated to 250 ° C. rice field. As a result, in the light emitting device 100, cracks were generated in the sealing resin 150 minutes after the start. On the other hand, in the light emitting device 50, a crack occurred in the sealing resin 170 minutes after the start.

Similarly, the same heating durability test was performed on the light emitting devices 50 and 100 having a structure in which the sealing resin contains a phosphor. As a result, in the light emitting device 100, cracks were generated in the sealing resin in 220 minutes. On the other hand, in the light emitting device 50, no crack occurred in the sealing resin even after 220 minutes had passed.

In addition, a test was conducted in which the shape change of the sealing resin was investigated with the light emitting devices 50 and 100 conducting. As a result, the light emitting device 100 cracked in the sealing resin in 667 hours. Further, in the light emitting device 100, the surface shape of the sealing resin has changed. On the other hand, in the light emitting device 50, no crack was generated in the sealing resin 53 even after 1000 hours had passed, and the shape change was smaller than that of the light emitting device 100.

When the sealing resin is configured as the light extraction surface, changes in shape during use such as deformation of the sealing resin and generation of cracks are directly linked to changes in optical characteristics. Therefore, it can be said that the slower the generation of cracks, the more the optical characteristics of the light emitting device do not change, and the longer the life of the light emitting device can be said. In this example, it was confirmed that in any of the above tests, the time until the cracks in the sealing resin were generated became longer or disappeared.

Even after curing, the thermosetting resin, which is the material of the sealing resin, gradually increases in hardness due to the use of the device (that is, by receiving heat), and finally deforms or cracks. This is due to the fact that stress is accumulated inside the resin by continuing to receive heat. Further, cracks and deformations of the resin are likely to occur in the surface region 53A in the portion open to the outside, that is, in the sealing resin 53. Further curing and deformation of the resin after use can be said to be deterioration of the sealing resin.

In this embodiment, since the surface region 53A of the sealing resin 53 has the unevenness P1, the surface region 53A functions as a stress relaxation layer for relaxing stress. Therefore, deformation or cracking of the sealing resin 53 after curing (after the start of use of the product) is suppressed, and the shape after curing is maintained for a long time. That is, by having the sealing resin 53, the light emitting device 50 becomes a long-life light emitting device that does not easily deteriorate.

In addition, the inventor of the present application conducted a test for investigating a change in light intensity when the light emitting devices 50 and 100 were conducted. As a result, even after 1000 hours passed, the light emitting device 50 had a light intensity of 97% or more immediately after the start even after 1000 hours passed. On the other hand, the light emitting device 100 had a light intensity of 90% to 95% immediately after the start after 1000 hours had passed. Therefore, it was confirmed that the decrease in light intensity was suppressed by suppressing the deterioration of the sealing resin 53. That is, by having the sealing resin 53, the light emitting device 50 becomes a high quality and long life light emitting device.

In this embodiment, the case where the light emitting device 50 has the sealing resin 53 as the sealing body has been described. However, the sealing resin 53 may have a lens shape, for example, like the light emitting device 10. For example, even when the sealing resin 53 has an outer shape similar to that of the lens 13, the light emitting device 50 has a high quality and long life lens.

Further, in this embodiment, the case where the mounting substrate 51 has the recess 51R and the light emitting element 12 is mounted in the recess 51R has been described. However, the mounting substrate 51 does not have to have the recess 51R. For example, the mounting substrate 51 may have a flat plate shape, and the light emitting element 12 may be mounted on the main surface (flat surface) of the mounting substrate 51.

In the case of a sealing resin having no lens function, a light emitting element 12 is mounted in the recess 51R like the mounting substrate 51, and the inside of the recess 51R is determined as a sealing region, for example, gold. The sealing resin 53 can be easily and stably formed without using a mold or the like.

Further, in the present embodiment, the case where the light emitting device 50 has the light emitting element 12 has been described, but the configuration of the light emitting element 12 is not limited to this. For example, the light emitting device 50 may have a light emitting element 41 having a plurality of light emitting segments 41A, as in the light emitting device 40. In this case, the sealing resin 53 may integrally seal the entire light emitting segment 41A, or may have a sealing segment that individually seals each of the light emitting segments 41A. ..

Further, in this embodiment, the case where the surface region 53A of the sealing resin 53 has the unevenness P1 on the external exposed surface S1 and the unevenness P2 on the interface S2 with the internal region 53B has been described. However, the surface region 53A may include the unevenness P1 on the externally exposed surface S1. By having the unevenness P2 at the interface S2 between the surface region 53A and the internal region 53B, the stress relaxation effect of the sealing resin 53 by the surface region 53A can be increased or stabilized, and the life can be extended.

As described above, in the present embodiment, the light emitting device 50 is formed on the mounting board 51, the light emitting element 12 mounted on the mounting board 51, and the light emitting element 12 so as to be embedded. It is made of a resin molded body, has a surface region 53A and an internal region 53B having different hardness from each other, and has a sealing resin 53 having a wavy structure including a plurality of unevennesses P1 on the externally exposed surface S1 of the surface region 53A. Therefore, deterioration of the sealing resin 53 is suppressed, and a high-quality and long-life light emitting device 50 can be provided.

10, 10A, 10B, 20, 20A, 20B, 30, 40, 50 Light emitting device 11, 51 Mounting substrate 12, 41 Light emitting element 13, 14, 15, 21, 22, 23, 31, 42 Lens (resin molded body)
53 Sealing resin 13A, 53A Surface area 13B, 53B Internal area 13P Thermosetting resin 13P1 Surface part BS, BS1 Base part LZ, LZ1 to LZ3 Lens part

Claims (16)

The process of mounting the light emitting element on the mounting board and
A step of applying a thermosetting resin on the mounting substrate so as to embed the light emitting element, and a step of applying the thermosetting resin.
A step of irradiating the thermosetting resin with plasma or infrared rays to cure only the surface portion of the thermosetting resin.
A method for manufacturing a light emitting device, comprising a step of heating and curing the thermosetting resin having a cured surface portion to form a resin molded body. The step of curing only the surface portion of the thermosetting resin is characterized by including a step of forming a plurality of irregularities on the surface portion of the thermosetting resin and roughening the surface portion. The method for manufacturing a light emitting device according to claim 1. The process of applying thermosetting resin on the substrate and
A step of irradiating the thermosetting resin with plasma or infrared rays to cure only the surface portion of the thermosetting resin.
A method for producing a resin molded product, which comprises a step of heating and curing the thermosetting resin whose surface portion has been cured. With the mounting board
The light emitting element mounted on the mounting board and
It is composed of a resin molded body using only one thermosetting resin formed on the mounting substrate so as to embed the light emitting element, and has a surface region and an internal region having different hardness from each other. A light emitting device characterized by that. The light emitting device according to claim 4, wherein the lens has an optical axis in a direction different from the optical axis of the emitted light of the light emitting element. The lens has a frustum-shaped base portion formed on the mounting substrate and tapered toward the mounting substrate, and a lens portion integrally formed on the base portion with the base portion. The light emitting device according to claim 4 or 5. The lens is integrally formed with a base portion formed on the mounting substrate and the base portion on the base portion, and has a protruding region protruding from the base portion in a horizontal direction to the mounting substrate. The light emitting device according to claim 4 or 5, further comprising a unit. The light emitting device according to claim 7, wherein the base portion has a frustum shape that is tapered toward the mounting substrate. The light emitting device according to claim 7 or 8, wherein the lens unit has an optical axis in a direction different from the optical axis of the emitted light of the light emitting element. The light emitting device according to any one of claims 4 to 9, wherein the lens has a plurality of lens portions on the light emitting element. The light emitting element has a plurality of light emitting segments juxtaposed on the mounting substrate.
The light emitting device according to any one of claims 4 to 10, wherein the lens has a lens portion formed on each of the plurality of light emitting segments. With the mounting board
The light emitting element formed on the mounting substrate and
It is made of a resin molded body using only one thermosetting resin formed on the mounting substrate so as to embed the light emitting element, and has surface regions and internal regions having different hardness from each other, and the surface region. A light emitting device comprising a sealing resin having a wavy structure including a plurality of irregularities on the externally exposed surface of the above. The light emitting device according to claim 12, wherein the sealing resin has a plurality of irregularities reflecting the plurality of irregularities on the externally exposed surface at the interface between the surface region and the internal region. The mounting board has a recess and has a recess.
The light emitting element is mounted on the bottom surface of the recess of the mounting substrate.
The light emitting device according to claim 12, wherein the sealing resin is formed so as to fill the recesses of the mounting substrate. The light emitting device according to claim 12, wherein the sealing resin has a lens shape. The sealing resin has translucency with respect to the emitted light of the light emitting element.
The light emitting device according to any one of claims 12 to 15, wherein the sealing resin contains phosphor particles.

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