JP2020088301A - Light-emitting device - Google Patents

Abstract

To provide a light-emitting device in which color mixing of luminous colors of red, green and blue is improved without up-sizing a substrate or complicating a pattern of the substrate.SOLUTION: Multiple component aggregation units 12, where a first light-emitting element 16R emitting red light, a second light-emitting element 16G emitting green light and a third light-emitting element 16B emitting blue light are placed, in contact, on a metal substrate 13 and encapsulated with encapsulation resin are backside mounted on a resin substrate. Since the light-emitting elements of respective colors are placed in contact, the component aggregation units 12 have color mixing. Consequently, a light-emitting device excellent in color mixing can be provided, by backside mounting multiple component aggregation units 12 on the resin substrate. Furthermore, since multiple component aggregation units 12 of the same structure are backside mounted, adjoining component aggregation units 12 can be connected by the electrode pattern of the resin substrate, and thereby the electrode patter can be reduced significantly or can be simplified.SELECTED DRAWING: Figure 1

Description

The present invention relates to a light emitting device used for a light source, illumination, a light projector, illumination, etc., and more particularly, to a device excellent in color mixing of emission colors.

Conventionally, in a light emitting device equipped with a large number of light emitting elements that respectively emit red light, green light, and blue light, as shown in FIG. 9, the surface of a substrate 1 is provided with a light emitting region 2 for each of red, green, and blue emission colors. 3 and 4 are divided, a large number of light emitting elements are arranged in each light emitting region, and a large number of light emitting elements are collectively covered with a sealing resin mixed with a phosphor for each light emitting region (for example, See Patent Documents 1 and 2.

JP, 2016-31951, A JP, 2018-46113, A

However, in the above-described conventional light emitting device, since the light emitting regions 2, 3 and 4 that emit light are separated from each other, there is a problem that the color mixing property is not good. Further, as shown in FIG. 9, since the encapsulating resin is applied to the respective light emitting regions 2, 3 and 4, the light emitting regions 2, 3 and 4 are separated by the dam material 5 serving as a bank. The material 5 became a dark part, and each light emitting region was divided more clearly, which prevented color mixing.

Further, in order to improve the color mixing property, when light emitting elements having different emission colors are dispersed and mounted on the substrate, it is necessary to separately wire the respective emission colors on the substrate, which complicates the wiring pattern and reduces the wiring pattern. There is a problem that the outer shape of the substrate becomes large in order to secure a space for providing the space.

The problem to be solved by the present invention is to solve the above-mentioned problems of the prior art, and to improve the color mixing property of red, green and blue emission colors without increasing the size of the substrate or complicating the pattern of the substrate. It is to provide a light emitting device.

The light-emitting device of the present invention has a metal substrate having an electrode at the end portion of the surface and provided with a conductive pattern from the electrode toward the center, and is bonded in close proximity to the center of the metal substrate and bonded to the conductive pattern. The first light emitting element that emits red light, the second light emitting element that emits green light, the third light emitting element that emits blue light, and the first to third light emitting elements that are connected to each other are sealed. And a plurality of through holes corresponding to the first to third light emitting elements of the element assembly unit, and the electrode of the metal substrate around the back surface side of the through hole. And a resin substrate having an electrode pattern connected to, and a plurality of the element assembly units are back-mounted on the resin substrate. In this light emitting device, since a plurality of element assembly units having excellent color mixing property are provided, the color mixing property of the light emitting device is also excellent.

In the element assembly unit mounted on the resin substrate in this light emitting device, corresponding electrodes of adjacent element assembly units are connected by the electrode pattern of the resin substrate. By connecting the electrodes of the adjacent element assembly units in this way, the electrode pattern of the resin substrate can be reduced or simplified. Further, since the electrode pattern of the resin substrate is arranged and mounted on the back surface so as to substantially overlap with the element assembly unit, it is not necessary to extremely increase the area occupied by the electrode pattern of the resin substrate even when a large number of element assembly units are provided. ..

In the light emitting device of the present invention, the first light emitting element that emits red light, the second light emitting element that emits green light, and the third light emitting element that emits blue light are closely arranged and sealed on the metal substrate. A plurality of element assembly units sealed with a stop resin are mounted on the back surface of a resin substrate. In this way, by arranging the light emitting elements of the respective colors in close proximity to each other, it is possible to form an element assembly unit having a good color mixing property. Therefore, by mounting a plurality of the element assembly units on the back surface of the resin substrate, it is possible to provide a light emitting device having excellent color mixing.

Further, in the light emitting device of the present invention, since a plurality of element assembly units having the same structure are mounted on the resin substrate on the back surface, it becomes possible to connect the adjacent element assembly units with each other by the electrode pattern of the resin substrate. By connecting the element assembly unit to, it is possible to significantly reduce or simplify the electrode pattern on the resin substrate, as compared with the case where a plurality of light emitting elements having different emission colors are mounted.

FIG. 3 is a plan view showing an element assembly unit of the light emitting device according to the embodiment of the present invention. FIG. 2 is a cross-sectional view of main parts of the element assembly unit shown in FIG. 1. FIG. 2 is an enlarged cross-sectional view of a main part around the light emitting element shown in FIG. 1. FIG. 4 is an enlarged cross-sectional view of an essential part around a light emitting element when the specifications of the metal substrate shown in FIG. 3 are changed. FIG. 2 is a plan view showing a light emitting device in which a large number of the element assembly units shown in FIG. 1 are mounted on the back surface of a resin substrate. FIG. 6 is a cross-sectional view of main parts of the light emitting device shown in FIG. 5. It is explanatory drawing which shows an example of arrangement|positioning of the electrode pattern of the resin substrate when the element assembly unit shown in FIG. It is explanatory drawing which shows the other example of arrangement|positioning of the electrode pattern of the resin substrate when the element assembly unit shown in FIG. It is a top view which shows the conventional light-emitting device.

As shown in FIGS. 5 and 6, the light emitting device 10 according to the present embodiment includes a resin substrate 11 and a plurality of element assembly units 12 mounted on the resin substrate 11 from the back surface.

The resin substrate 11 is made of white resin and has a plurality of through holes 11 a corresponding to the portions of the element assembly unit 12 where the light emitting elements are provided. Further, an electrode pattern 27 connected to the electrode of the element assembly unit 12 is provided around the back surface side of the through hole 11 a in the resin substrate 11.

As shown in FIGS. 1 and 2, the element assembly unit 12 includes a metal substrate 13 made of aluminum or the like having an elongated rectangular shape. Anode-side electrodes 14R, 14G and 14B and cathode-side electrodes 15R, 15G and 15B are provided at both ends in the longitudinal direction on the surface of the metal substrate 13. Further, from the anode side electrodes 14R, 14G, 14B, conductive patterns 14r, 14g, 14b for element connection are drawn toward the center of the metal substrate 13, respectively, and from the cathode side electrodes 15R, 15G, 15B, respectively. Conductive patterns 15r, 15g, and 15b for element connection are drawn out toward the center of the metal substrate 13, respectively.

In the center of the metal substrate 13, a first light emitting element 16R for emitting red light, a second light emitting element 16G for emitting green light, and a third light emitting element 16B for emitting blue light are arranged in proximity. ing. As shown in FIG. 3, the first light emitting element 16R in the present embodiment includes an element in which a phosphor resin 18 mixed with a phosphor that converts red light is provided on the blue light emitting element 17. The second light emitting element 16G is composed of a blue light emitting element 17 on which a phosphor resin 19 mixed with a phosphor for converting into green light is provided. Further, the third light emitting element 16B includes a blue light emitting element 17. It is also possible to use an ultraviolet light emitting element in place of the blue light emitting element 17, and in that case, as the third light emitting element 16B, fluorescent light mixed with a phosphor that converts blue light onto the ultraviolet light emitting element is used. It is desirable to provide a body resin.

Further, the second light emitting element 16G in the present embodiment is configured by an element in which two or more light emitting elements are connected as shown in FIG. 1 in consideration of the weak emission intensity of green light. There is.

Further, the first to third light emitting elements 16R, 16G, 16B are closely arranged in the center of the metal substrate 13 in two or more rows and columns as shown in FIG. 1, and as shown in FIGS. It is mounted on the metal substrate 13 by the white die bonding paste 20.

As shown in FIGS. 1 and 2, the first to third light emitting elements 16R, 16G, and 16B thus mounted on the metal substrate 13 are rectangles provided on the metal substrate 13 close to them. It is surrounded by a frame-shaped dam material 21 and is sealed with a sealing resin 22 filled inside the dam material 21. A filler that diffuses light may be mixed in the sealing resin 22.

In the above-described metal substrate 13, as shown in FIG. 1, the distance between the opposite sides 13a, 13b on one side is substantially equal to the length of one side of the dam member 21, and the electrodes 14R, 14G, 14B on the anode side and the electrodes on the cathode side are formed. Since 15R, 15G, and 15B are provided, the distance between the opposite sides 13c and 13d on the other side is set to be longer than the distance between the opposite sides 13a and 13b.

Further, as shown in FIG. 4, when the surface of the metal substrate 13 made of aluminum or the like is provided with a surface treatment layer 25 such as vapor-deposited silver for improving light reflection, the surface treatment layer 25 is protected. Therefore, it is preferable that the surfaces of the metal substrate 13 as well as the first to third light emitting elements 16R, 16G, and 16B be covered with the top coat 26 made of transparent resin.

As shown in FIG. 5 and FIG. 6, the element assembly unit 12 having the above-described configuration is used, together with the first to third light emitting elements 16R, 16G, and 16B, the dam material 21 and the sealing resin 22 are adapted to the through hole 11a. Then, when a large number of back surfaces are mounted on the resin substrate 11 from the back surface of the resin substrate 11 so as to be exposed on the front surface side, at this time, the electrodes 14R, 14G, 14B on the anode side and the electrodes 15R, 15G on the cathode side of the element assembly unit 12 are mounted. , 15B come into contact with the electrode pattern 27 of the resin substrate 11 and are connected by joining or the like.

As shown in FIG. 7, when viewed from the front of the resin substrate 11, the element grouping unit 12 is such that the opposite sides 13a and 13b of the metal substrates 13 of the adjacent element grouping units 12 are close to each other and the first to third groups are arranged. The central portions where the light emitting elements 16R, 16G and 16B are provided are arranged close to each other so that they are staggered. When the element assembly unit 12 is arranged in this way, it becomes difficult to draw the electrode pattern 27 around the electrode portions T1 and T2 surrounded by the element assembly unit 12, but the anode side of the element assembly unit 12 arranged in the horizontal direction in the drawing. When the electrodes 14R, 14G, 14B and the electrodes 15R, 15G, 15B on the cathode side approach each other, the corresponding electrodes can be connected by the electrode pattern 27 provided on the resin substrate 11, which is easy. Can be connected to. Therefore, even if the element assembly units 12 are densely packed, the electrode pattern 27 is extremely simple, and it is not necessary to draw it largely. Note that, in FIG. 7, the electrode pattern 27 is shown by a chain double-dashed line only at that position, and the corresponding electrodes of the electrodes 14R, 14G, 14B on the anode side and the electrodes 15R, 15G, 15B on the cathode side which are adjacent to each other are shown. The connection is shown in a simplified manner.

Further, as shown in FIG. 8, when seen from the front side of the resin substrate 11, the opposite sides 13a and 13b of the metal substrates 13 of the adjacent element assembly units 12 approach each other, and the first to third light emitting elements 16R. , 16G, 16B are arranged adjacent to each other so that the central portions thereof are arranged vertically in the drawing, the electrode portion T3 surrounded by the element collecting unit 12 has the element collecting units 12 adjacent to each other in the drawing. The electrode pattern 27 can be connected to the electrode or the electrode of the element assembly unit 12 that is vertically adjacent in the drawing by the electrode pattern 27, and can be easily connected.

When the element assembly unit 12 is mounted on the resin substrate 11 on the back surface as described above, the first to third light emitting elements 16R, 16G, and 16B are already arranged close to each other and have a good color mixing property. Even if the element assembly unit 12 is mounted as described above, good color mixture can be maintained.

Further, by appropriately disposing and mounting the element assembly unit 12 on the resin substrate 11, it is possible to reduce the weight as compared with a light emitting device in which a large number of light emitting elements are mounted on one large metal substrate. In particular, by providing a large number of through holes 11a in the resin substrate 11 and mounting the element assembly unit 12 from the back surface side, it is possible to further reduce the weight of the resin substrate 11 by the amount of the through holes 11a.

Most of the heat from the first to third light emitting elements 16R, 16G, 16B is directly below the central portion of the metal substrate 13 on which the first to third light emitting elements 16R, 16G, 16B are arranged. It has been confirmed that heat is dissipated to the back side. Therefore, it is not necessary to laterally extend the metal substrate 13 in order to improve heat dissipation. Therefore, the element assembly unit 12 has an excellent color mixing property with a minimum size while maintaining good heat dissipation.

Further, by mounting the element assembly unit 12 on the resin substrate 11, it is possible to reduce the metal substrate portion as compared with the case of using one large metal substrate, and it is possible to significantly reduce the cost.

DESCRIPTION OF SYMBOLS 1 substrate 2,3,4 light emitting area 5 dam material 10 light emitting device 11 resin substrate 11a through hole 12 element assembly unit 13 metal substrate 14R, 14G, 14B anode side electrodes 14r, 14g, 14b conductive pattern 15R, 15G, 15B cathode Side electrodes 15r, 14g, 14b Conductive pattern 16R First light emitting element 16G Second light emitting element 16B Third light emitting element 17 Blue light emitting element 18 Phosphor resin 19 Phosphor resin 20 Die bonding paste 21 Dam material 22 Sealing Resin 25 Surface treatment layer 26 Top coat 27 Electrode pattern T1, T2, T3 Electrode part

Claims (6)

A metal substrate having an electrode at the end of the surface and provided with a conductive pattern from the electrode toward the center,
A first light emitting device for emitting red light, a second light emitting device for emitting red light, and a third light emitting device for emitting blue light, which are closely arranged in the center of the metal substrate and are bonded to the conductive pattern. Light emitting element of
A sealing resin for sealing the first to third light emitting elements,
An element assembly unit including
A resin substrate having a plurality of through holes corresponding to the first to third light emitting elements of the element assembly unit, and having an electrode pattern connected to an electrode of the metal substrate around the back surface side of the through holes;
A light-emitting device comprising: a plurality of the element assembly units mounted on the back surface of the resin substrate. The light emitting device according to claim 1, wherein, in the element assembly unit mounted on the resin substrate, corresponding electrodes of adjacent element assembly units are connected by the electrode pattern of the resin substrate. The first light emitting element is an element provided with a phosphor resin mixed with a phosphor for converting into red light on a blue light emitting element or an ultraviolet light emitting element,
The second light emitting element is an element in which a phosphor resin mixed with a phosphor for converting to green light is provided on a blue light emitting element or an ultraviolet light emitting element,
The light emitting device according to claim 1, wherein the third light emitting element comprises a blue light emitting element or an ultraviolet light emitting element and an element provided with a phosphor resin mixed with a phosphor for converting into blue light. The light emitting device according to claim 1, wherein the second light emitting element is an element in which two or more blue light emitting elements or ultraviolet light emitting elements are connected. The first to third light emitting elements are arranged close to each other in two or more vertical and horizontal rows, a dam material surrounding the first to third light emitting elements is provided, and the sealing resin is provided inside thereof. Item 5. The light emitting device according to item 1 or 3. The metal substrate has a rectangular shape, and the distance between the opposite sides of one side is substantially equal to the length of one side of the dam member, and the distance between the opposite sides of the other is set longer than the distance between the one opposite sides. The light emitting device according to claim 5, wherein the electrode is provided near the electrode.

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