JP2020072144A - Light-emitting device - Google Patents

Abstract

To provide a light-emitting device with little color unevenness.SOLUTION: A light-emitting device comprises: a first light-emitting element 10 which emits light with a first peak wavelength of greater than or equal to 430 nm and less than 490 nm; a second light-emitting element 20 which emits light with a second peak wavelength of greater than or equal to 490 nm and less than or equal to 570 nm; and a coating member 40 including a wavelength conversion member 41 which continuously coats an upper surface of the first light-emitting element and an upper surface of the second light-emitting element and converts light with the first or second peak wavelength to light with a third peak wavelength, a translucent member 43 which coats an upper surface of the wavelength conversion member 41, and a reflection member 42 located between the wavelength conversion member 41 and the translucent member 43. In a plan view, the coating member 40 includes a first region overlapping the upper surface of the first light-emitting element and a second region overlapping the upper surface of the second light-emitting element, and a third region overlapping a portion between the first region and the second region. A transmittance of the third region is higher than the first and second regions.SELECTED DRAWING: Figure 2A

Description

  The present disclosure relates to a light emitting device.

  Light emitting devices such as light emitting diodes (LEDs) are used as various light sources. For example, Patent Document 1 discloses a light emitting device for a backlight of a liquid crystal display device having excellent color reproducibility.

JP, 2014-39052, A

  The present disclosure provides a light emitting device with less color unevenness.

  A light emitting device of the present disclosure includes a first light emitting element that emits light having a first peak wavelength of 430 nm or more and less than 490 nm, and a second light emitting element that emits light having a second peak wavelength of 490 nm or more and 570 nm or less. , The upper surface of the first light emitting element and the upper surface of the second light emitting element are continuously covered, and at least one of the light having the first peak wavelength and the light having the second peak wavelength is A wavelength conversion member that converts light having a third peak wavelength different from the second peak wavelength, a translucent member that covers the upper surface of the wavelength conversion member, and the wavelength conversion member and the translucent member. And a covering member including a reflecting member positioned between the reflecting member and the reflecting member, the covering member including a first region overlapping the upper surface of the first light emitting element in a top view, and the upper surface of the second light emitting element. A second region comprising a first region, and a third region overlapping with between the second region, the transmittance of the third region is higher than the first region and the second region.

  According to the present disclosure, it is possible to realize a light emitting device with less color unevenness.

FIG. 1A is a perspective view of an embodiment of a light emitting device according to the present disclosure as viewed from the upper surface side. FIG. 1B is a perspective view of an embodiment of a light emitting device according to the present disclosure as viewed from the lower surface side. FIG. 1C is a top view of an embodiment of a light emitting device according to the present disclosure. 2A is a sectional view taken along line 2A-2A in FIG. 1C. 2B is a sectional view taken along line 2B-2B in FIG. 1C. FIG. 3A is a top view of the base body. FIG. 3B is a top view of a light emitting device without a translucent member. FIG. 3C is a diagram showing the positions of the first to fifth regions in the covering member. FIG. 4 is a cross-sectional view showing another form of the light emitting device according to the present disclosure. FIG. 5 is a cross-sectional view showing another form of the light emitting device according to the present disclosure.

  Embodiments of a light emitting device of the present disclosure will be described below with reference to the drawings. The light emitting devices described below are some examples of the embodiments, and the light emitting device of the present disclosure is not limited to the forms described below. Further, the features described in one embodiment can be applied to other embodiments and modifications. Furthermore, the size, positional relationship, etc. of the members shown in the drawings may be exaggerated in order to clarify the explanation.

  1A and 1B are perspective views of the light emitting device 101 as viewed from the upper surface side and the lower surface side. FIG. 1C is a front view of the light emitting device 101. 2A and 2B are cross-sectional views of the light emitting device 101 taken along the lines 2A-2A and 2B-2B in FIG. 1C.

  As shown in FIG. 2A, the light emitting device 101 includes a first light emitting element 10, a second light emitting element 20, a third light emitting element 30, and a covering member 40. In the present embodiment, the light emitting device 101 includes three light emitting elements, but the number of light emitting elements included in the light emitting device 101 may be two or more. The 1st light emitting element 10, the 2nd light emitting element 20, and the 3rd light emitting element 30 may be called a light emitting element. The first peak wavelength, which is the emission peak wavelength of the first light emitting element 10, is 430 nm or more and less than 490 nm. The second peak wavelength, which is the emission peak wavelength of the second light emitting element 30, is 490 nm or more and 570 nm or less. In the present embodiment, the light emitting device 101 includes the protective member 50 that covers the first light emitting element 10, the second light emitting element 20, the third light emitting element, and the covering member 40, the first light emitting element 10, the second light emitting element 20, and A base 60 for electrically connecting the third light emitting element 30 to the outside and a light guide member 70 for covering the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 are further provided.

  As shown in FIG. 1A, the light emitting device 101 is a so-called side-view type light emitting device, and the protective member 50 is arranged so as to cover the side surface of the covering member 40. The 1st light emitting element 10, the 2nd light emitting element 20, and the 3rd light emitting element 30 arrange | positioned in the protection member 50 permeate | transmit the covering member 40, and radiate | emits light to the positive direction of a Z-axis. Since the peak wavelengths of the plurality of light emitting elements are different, the wavelength region where the emission intensity is reduced can be reduced, and the light emitting device 101 can emit white light with high color reproducibility. Further, since the covering member 40 includes the wavelength conversion member and the reflection member, it is possible to effectively mix the light emitted from the plurality of light emitting elements and the wavelength-converted light, and emit the light with less color unevenness. it can.

  The light emitting device 101 has an upper surface 101a, a lower surface 101b, and side surfaces 101c, 101d, 101e, 101f. These planes are referred to when designating a specific plane in the outer shape of the light emitting device 101. Hereinafter, each component of the light emitting device 101 will be described in detail.

(First light emitting element 10, second light emitting element 20, third light emitting element 30)
The first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 are semiconductor elements that emit light by applying a voltage, and are known semiconductor elements such as LED chips made of a nitride semiconductor or the like. is there.

  The first light emitting element 10 includes an element substrate 11, a semiconductor laminated body 12, and electrodes 13A and 13B. The semiconductor stacked body 12 has an upper surface 12a and a lower surface 12b, and the element substrate 11 is connected to the upper surface 12a. In the present embodiment, the configuration in which the first light emitting element 10 includes the element substrate 11 will be described as an example, but the element substrate 11 may be removed.

The semiconductor laminated body 12 is preferably a laminated body of nitride semiconductors as described above. Specifically, the semiconductor stack 12 is constituted by a laminate of semiconductor layers represented by the general formula _{In x Al y Ga 1-x} -y N (0 ≦ x, 0 ≦ y, x + y ≦ 1) .. The semiconductor stacked body 22 includes a light emitting layer and a p-type semiconductor layer and an n-type semiconductor layer that sandwich the light emitting layer. The semiconductor composition and structure of the light emitting layer determines the wavelength of light emitted from the light emitting device 101.

  The element substrate 11 is, for example, a crystal growth substrate for epitaxially growing the semiconductor laminate 12. Generally, the semiconductor laminated body 12 is formed on the element substrate 11 by a crystal growth method. After the semiconductor laminated body 12 is formed on the crystal growth substrate different from the element substrate 11, the semiconductor laminated body 12 may be separated and the semiconductor laminated body 12 and the element substrate 11 may be bonded to each other. The element substrate 11 preferably has a light-transmitting property. Thereby, the upper surface 11a of the element substrate 11 which is not in contact with the semiconductor laminated body 12 can be used as the light extraction surface of the first light emitting element 10, and the first light emitting element 10 can be mounted on the base body 60 by flip chip bonding. it can. Examples of the material of the element substrate 11 include sapphire, gallium nitride, aluminum nitride, silicon, silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, zinc sulfide, zinc oxide, zinc selenide, diamond and the like. Of these, sapphire is preferable. The thickness of the element substrate 11 can be appropriately selected and is, for example, 0.02 mm or more and 1 mm or less, and from the viewpoint of the strength of the element substrate and / or the thickness of the light emitting device 101, 0.05 mm or more and 0.3 mm or less. Is preferred.

  The electrodes 13A and 13B are provided on the lower surface 12b of the semiconductor laminated body 12 and are electrically connected to the semiconductor laminated body 12. For example, the electrode 13A is a positive electrode and the electrode 13B is a negative electrode. The electrodes 13A and 13B can be made of gold, silver, copper, tin, platinum, rhodium, titanium, aluminum, tungsten, palladium, nickel or alloys thereof.

  The second light emitting element 20 has the same structure as the first light emitting element 10. Specifically, the second light emitting element 20 includes an element substrate 21, a semiconductor laminated body 22, and electrodes 23A and 23B. The semiconductor stacked body 22 has an upper surface 22a and a lower surface 22b, and the element substrate 21 is connected to the upper surface 22a. The electrodes 23A and 23B are provided on the lower surface 22b of the semiconductor stacked body 22. The second light emitting element 20 emits light from the upper surface 21 a of the element substrate 21.

  The third light emitting element 30 also has the same structure as the first light emitting element 10. Specifically, the third light emitting element 30 includes an element substrate 31, a semiconductor laminated body 32, and electrodes 33A and 33B. The semiconductor stacked body 32 has an upper surface 32a and a lower surface 32b, and the element substrate 31 is connected to the upper surface 32a. The electrodes 33A and 33B are provided on the lower surface 32b of the semiconductor laminated body 32. The third light emitting element 30 emits light from the upper surface 31 a of the element substrate 31.

  The first light emitting element 10 and the second light emitting element 20 respectively emit light having a first peak wavelength and light having a second peak wavelength. The third light emitting element 30 emits light having the same peak wavelength as the first peak wavelength or the second peak wavelength. Here, the two peak wavelengths being the same means that the value of one wavelength is within a range of ± 10 nm with respect to the value of the other wavelength. Alternatively, the third light emitting element 30 may emit light having a peak wavelength different from the first peak wavelength and the second peak wavelength.

  Since the light emitting device 101 includes two or more light emitting elements that emit light having peak wavelengths different from each other in the first peak wavelength and the second peak wavelength, color reproducibility of emitted light can be improved. In the present embodiment, the emission peak wavelength of the third light emitting element 30 is 430 nm or more and less than 490 nm, like the first light emitting element.

  In FIG. 1C, the outer shape of the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 in a top view is indicated by a broken line. It is preferable that the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 have a rectangular shape, particularly a square shape or a rectangular shape elongated in one direction in a top view. However, the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 may have other shapes, for example, may have a hexagonal shape in order to improve the light emission efficiency. .. The size of the outer shape of the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 in the top view may be, for example, the same or different. The 1st light emitting element 10, the 2nd light emitting element 20, and the 3rd light emitting element 30 are arranged in the longitudinal direction of each light emitting element, for example. As a result, the height of the light emitting device 101 in the Y axis direction can be reduced. In addition, when the first light emitting element 10 and the second light emitting element 20 are rectangular shapes that are long in one direction, it is preferable that the short side of the first light emitting element 10 and the short side of the second light emitting element 20 face each other. As a result, the height of the light emitting device 101 in the Y axis direction can be reduced.

(Base 60)
The base 60 mounts the first light emitting device 10, the second light emitting device 20, and the third light emitting device 30, and electrically connects the first light emitting device 10, the second light emitting device 20, the third light emitting device 30, and external terminals. Provide wiring to connect to. The base body 60 includes a base material 65, a first wiring 61, a second wiring 62, and a via conductor 63. As shown in FIGS. 1A, 1B and 2A, the base material 65 includes an upper surface 65a, a lower surface 65b, side surfaces 65c, 65d, 65e and 65f. The upper surface 65a is located on the upper surface 101a side of the light emitting device 101. The lower surface 65b is also the lower surface 101b of the light emitting device 101. Further, the side surfaces 65c, 65d, 65e, 65f respectively constitute a part of the side surfaces 101c, 101d, 101e, 101f of the light emitting device 101.

  The first wiring 61 is arranged on the upper surface 65 a of the base material 65. The first wiring 61 is preferably a convex portion 61t having a size corresponding to the electrodes 13A and 13B of the first light emitting element 10, the electrodes 23A and 23B of the second light emitting element 20 and the electrodes 33A and 33B of the third light emitting element 30. have. By having the convex portion 61t, the electrodes 13A and 13B, the electrodes 23A and 23B, the electrodes 33A and 33B, and the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 are melted and conductively bonded. When the members are bonded together, the self-alignment effect facilitates the alignment of the light emitting element and the substrate.

  The base material 65 includes a via hole 65h connecting the upper surface 65a and the lower surface 65b, and a concave portion 65g having openings on the lower surface 65b and the side surface 65d. In addition to the lower surface 65b and the side surface 65d, the end portion in the longitudinal direction of the base material 65 may be provided with a concave portion 65g that is open to the side surface 65e or the side surface 65f. The second wiring 62 is arranged in the lower surface 65b and the recess 65g. The depth of the concave portion 65g in the Z-axis direction is preferably 0.4 to 0.9 times the thickness of the base material 65 in the Z-axis direction of the base material 65. When the depth is larger than 0.4 times the thickness of the material of the base material 65, the area of the second wiring 62 formed in the recess 65g can be made sufficiently large. Further, since the depth of the concave portion 65g is shallower than 0.9 times the thickness of the base material 65, the strength reduction of the base material 65 can be suppressed.

  The via conductor 63 is arranged on the inner surface of the via hole 65h. The via conductor 63 is connected to the first wiring 61 and the second wiring 62, and the via conductor 63 electrically connects the first wiring 61 and the second wiring 62. The interior of the via hole 65h may be hollow or may be filled with an insulating material or a conductive material. For example, the via conductor 63 may be filled in the entire interior of the via hole 65h, or may be filled with the base material 65.

  By providing the base body 60 with the recessed portion 65g, it is possible to improve the bonding strength between the mounting substrate and the light emitting device 101 when the lower surface 101b of the light emitting device 101 is mounted on the mounting substrate such as a backlight module. This is because the contact area with the conductive adhesive member is increased by forming the second wiring 62 also in the concave portion 65g. This effect is particularly effective when the light emitting device 101 is used as a side-view type light emitting device, but the lower surface 65b of the base material 65, which is the lower surface 101b of the light emitting device 101, faces the mounting substrate. May be mounted on a mounting board. The base does not have to have the recess.

  FIG. 3A is a top view of the base body 60. In FIG. 3A, the via conductor 63 is shown by a broken line. The first wiring 61 arranged on the upper surface 65a includes a plurality of isolated patterns, and each isolated pattern is electrically connected to the second wiring 62 located on the lower surface 65b by at least one via conductor 63.

  The base body 60 has an insulating layer 64 in order to enhance insulation between the patterns of the second wirings 62 arranged on the lower surface 65b of the base material 65 and to prevent a short circuit due to solder or the like during mounting. Good. The insulating layer 64 is partially disposed between the patterns of the second wiring 62, and also covers a portion of the end portion of the second wiring 62 and is disposed on the second wiring 62.

  The base material 65 can be configured using an insulating member such as resin or fiber reinforced resin, ceramics, or glass. Examples of the resin or fiber reinforced resin include epoxy, glass epoxy, bismaleimide triazine (BT), and polyimide. Further, the base material 65 may contain a white pigment such as titanium oxide. Examples of ceramics include aluminum oxide, aluminum nitride, zirconium oxide, zirconium nitride, titanium oxide, titanium nitride, and mixtures thereof. Of these base materials, it is particularly preferable to use a base material having physical properties close to the linear expansion coefficient of the light emitting element. The lower limit of the thickness of the base material can be appropriately selected, but from the viewpoint of the strength of the base material, it is preferably 0.05 mm or more, and more preferably 0.2 mm or more. Further, the upper limit of the thickness of the base material is preferably 0.5 mm or less, and more preferably 0.4 mm or less from the viewpoint of the thickness (depth) of the light emitting device.

  The first wiring 61, the second wiring 62, and the via conductor 63 can be formed of copper, iron, nickel, tungsten, chromium, aluminum, silver, gold, titanium, palladium, rhodium, or an alloy thereof. The metal or alloy may be a single layer or a multilayer. In particular, copper or copper alloy is preferable from the viewpoint of heat dissipation. In addition, a layer of silver, platinum, aluminum, rhodium, gold, or an alloy thereof is formed on the surfaces of the first wiring 61 and the second wiring 62 from the viewpoint of wettability and / or light reflectivity of the conductive adhesive member. May be provided.

  The insulating layer 64 can be formed of various insulating materials. For example, a thermosetting resin or a thermoplastic resin may be used.

  The electrodes 13A and 13B of the first light emitting element 10, the electrodes 23A and 23B of the second light emitting element 20 and the electrodes 33A and 33B of the third light emitting element 30 are electrically connected to the first wiring 61 by using a conductive adhesive member such as solder. Are joined together. As a result, the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 are mounted on the base 60.

  As the conductive adhesive member, bumps of gold, silver, copper, etc., metal paste containing metal powder such as silver, gold, copper, platinum, aluminum, palladium and resin binder, tin-bismuth-based, tin-copper-based, tin Any one of silver-based, gold-tin-based solder, and brazing material such as low melting point metal can be used.

(Light guide member 70)
The light guide member 70 has translucency and covers the upper surface 11a of the first light emitting element 10, the upper surface 21a of the second light emitting element 20, and the upper surface 31a of the third light emitting element 30. Accordingly, the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 can be protected from external stress. When the light emitting device includes two light emitting elements, the first light emitting element and the second light emitting element, the light guide member 70 covers the upper surface 11a of the first light emitting element 10 and the upper surface 21a of the second light emitting element 20. To do. It is preferable that the light guide member 70 further covers the side surface and the lower surface of each light emitting element and is arranged on the upper surface 65 a of the base body 60. By covering the side surface and the lower surface of the light emitting element, the light emitted from the surface other than the upper surface of each light emitting element can be extracted to the outside, and the light extraction efficiency of the light emitting device 101 can be improved. Further, in the light guide member 70, it is possible to mix the colors of light emitted from the side surfaces of the respective light emitting elements.

  The light guide member 70 may include a wavelength conversion member described later. By doing so, color adjustment of the light emitting device 101 becomes easy.

  The light guide member 70 can be formed of silicone resin, epoxy resin, phenol resin, polycarbonate resin, acrylic resin, or modified resin thereof. Among them, the silicone resin and the modified silicone resin are preferable because they are excellent in heat resistance and light resistance. Specific silicone resins include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin. Also, epoxy resins are generally harder than silicone resins. Therefore, the strength of the light emitting device can be improved by using the epoxy resin for the light guide member 70. The light guide member 70 may include diffusing particles that can be included in the translucent member 43 of the covering member 40 described below.

(Coating member 40)
The covering member 40 continuously covers the upper surfaces of the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30, and among the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30, The wavelength of light emitted from at least one is converted into light of another wavelength. When the light emitting device includes two light emitting elements, the first light emitting element and the second light emitting element, the covering member 40 continuously covers the upper surfaces of the first light emitting element 10 and the second light emitting element 20. Further, the wavelength-converted light and the light emitted from these light emitting elements are mixed and diffused. For this reason, the covering member 40 includes a wavelength conversion member 41, a reflecting member 42, and a translucent member 43. In the present specification, the term “cover” means covering an object, which may or may not be in contact with the object.

  The wavelength conversion member 41 includes a base material and wavelength conversion particles contained in the base material. For the base material of the wavelength conversion member, for example, a material used as a translucent member can be used. The wavelength conversion member 41 is arranged on the upper surface 70a of the light guide member 70, and continuously covers the upper surfaces of the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30. For example, the wavelength conversion member 41 is arranged and continuously covers the upper surfaces of the first light emitting device 10, the second light emitting device 20, and the third light emitting device 30. The wavelength conversion member 41 has at least one of the first peak wavelength light emitted from the first light emitting element 10 and the second peak wavelength light emitted from the second light emitting element 20 as the first peak wavelength and the second peak wavelength. To a light having a third peak wavelength different from.

  The translucent member 43 covers the upper surface 41 a of the wavelength conversion member 41. By covering the upper surface 41a of the wavelength conversion member 41, the translucent member 43 suppresses the wavelength conversion member 41 from being exposed to an external environment including water and the like, and converts the wavelength included in the wavelength conversion member 41. Prevents particles from deteriorating. The upper surface 43 a of the translucent member 43 is also the upper surface of the covering member 40.

  The reflection member 42 is arranged between the translucent member 43 and the wavelength conversion member 41. The reflection member 42 includes reflective particles and reflects incident light in random directions. Specifically, the reflecting member 42 includes reflecting portions 42 </ b> A to 42 </ b> G containing reflecting particles, and is partially arranged between the translucent member 43 and the wavelength converting member 41. Therefore, as a whole of the covering member 40, the light transmittance in the region where the reflecting portions 42A to 42G are not arranged is higher than the light transmittance in the region where the reflecting portions 42A to 42G are arranged.

  For example, the reflecting portions 42A and 42B are located on the upper surface 11a of the first light emitting element 10, the reflecting portions 42C, 42D and 42E are located on the upper surface 21a of the second light emitting element 20, and the upper surface 31a of the third light emitting element 30. It is arranged in the covering member 40 so that the reflecting portions 42F and 42G are located above. That is, you may arrange | position a some reflection part on the upper surface of each light emitting element. FIG. 3B is a top view of the light emitting device 101 from which the translucent member 43 is removed. As shown in FIGS. 2A and 3B, in the present embodiment, the reflection parts 42A and 42B are located on the upper surface 11a of the first light emitting element 10, and the reflection parts 42C, 42D and 42E are the second light emitting element 20. It is located on the upper surface 21a. The reflectors 42F and 42G are located on the upper surface 31a of the third light emitting element 30. The reflective portions 42A to 42G are provided on a region between the upper surface 11a of the first light emitting element 10 and the upper surface 21a of the second light emitting element 20, and the upper surface 21a of the second light emitting element 20 and the upper surface 31a of the third light emitting element 30. It is not located in the area above. The side surfaces of the reflection portions 42A to 42G are covered with at least one of the translucent member 43 and the wavelength conversion member 41.

  In the present embodiment, the reflection parts 42A to 42G have a circular shape in a top view. However, the shape of the reflecting portions 42A to 42G in top view is not limited to a circle, and may be a polygon such as a triangle or a quadrangle, or may have another shape. Further, the number of reflecting portions arranged on the upper surface of each light emitting element is not limited to the example shown in FIG. 3B. The reflectors 42A to 42G are not arranged between the upper surfaces 11a, 21a, 31a of the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30.

  In the area where the reflecting portions 42A to 42G are arranged in the covering member 40, a part of the light incident on the covering member 40 is reflected in random directions in the reflecting portions 42A to 42G, so that the light transmittance is reduced. FIG. 3C is a diagram illustrating the transmittance of the covering member 40. In the top view, of the covering member 40, a third region 45c located between a first region 45a overlapping the upper surface 11a of the first light emitting element 10 and a second region 45b overlapping the upper surface 21a of the second light emitting element 20. The light transmittance of is higher than the light transmittance of the first region 45a and the second region 45b. Further, in the covering member 40, the light of the fifth region 45e located between the second region 45b overlapping the upper surface 21a of the second light emitting element 20 and the fourth region 45d overlapping the upper surface 31a of the third light emitting element 30. Has a higher transmittance than the light transmittance of the second region 45b and the fourth region 45d. Here, the light transmittance is a value averaged in each region. Further, the light transmittance is the transmittance at the first peak wavelength and the second peak wavelength, and the light transmittance of the third region 45c is the first peak wavelength and the second peak wavelength, respectively. It is higher than the light transmittance of the first region 45a and the second region 45b.

  For the wavelength conversion member 41, one of the following wavelength conversion particles may be used alone or two or more of them may be used in combination. Further, the wavelength conversion member 41 may include a plurality of wavelength conversion layers made of different materials. For example, the wavelength conversion member 41 may be composed of a single layer containing a phosphor that emits green light or a wavelength conversion particle that emits red light, or a wavelength conversion layer that contains wavelength conversion particles that emits green light and a red light. It may have a structure in which wavelength conversion layers containing wavelength conversion particles that emit light are laminated. Alternatively, the wavelength conversion member 41 may be composed of a wavelength conversion layer including a phosphor that emits green light and wavelength conversion particles that emit red light.

  For example, when the first light emitting element 10 and the third light emitting element 30 emit light in the blue wavelength range (430 nm or more and less than 490 nm), and the second light emitting element 20 emits light in the green wavelength range (490 nm or more and 570 nm or less). The wavelength conversion member 41 preferably includes wavelength conversion particles that emit red light having a wavelength of 610 nm or more and 750 nm or less. That is, the light having the first peak wavelength, the light having the second peak wavelength, and the light having the third peak wavelength are lights in the blue, green, and red wavelength bands, respectively. By doing so, a light emitting device capable of emitting light with excellent color reproducibility can be obtained. In addition, green light generally has higher visibility than blue light. Therefore, the light having the second peak wavelength is reflected by the covering member 40 more than the light having the first peak wavelength, whereby the blue light, the green light, and the red light are mixed more uniformly. Therefore, the transmittance in the second region 45b overlapping the upper surface 21a of the second light emitting element 20 which emits the light having the second peak wavelength is determined by the upper surface 11a of the first light emitting element 10 which emits the light having the first peak wavelength. It is preferable to make the transmittance lower than the transmittance of the first region 45a overlapping with, that is, to make the transmittance of the first region higher than the transmittance of the second region 45b.

The wavelength converting particles emitting green, yttrium-aluminum-garnet fluorescent material (e.g., _{Y3 (Al, Ga) 5 O} 12: Ce), lutetium-aluminum-garnet fluorescent material (e.g., _Lu 3 (Al, Ga) ₅ O ₁₂ : Ce), terbium aluminum garnet-based phosphor (for example, Tb ₃ (Al, Ga) ₅ O ₁₂ : Ce) -based phosphor, and silicate-based phosphor (for example (Ba, Sr) ₂ SiO ₄ : Eu). ), chloro silicate-based phosphor (e.g. _{Ca 8 Mg (SiO 4) 4} Cl 2: Eu), β -sialon-based phosphor (e.g. _{Si 6-z Al z O z} N 8-z: Eu (0 <z <4 .2)), SGS-based phosphors (for example, SrGa ₂ S ₄ : Eu), and the like. The wavelength conversion particles that emit yellow light include α-sialon-based phosphors (for example, Mz (Si, Al) ₁₂ (O, N) ₁₆ (where 0 <z ≦ 2, and M is Li, Mg, Ca, Y). , And lanthanide elements other than La and Ce), etc. In addition, among the wavelength conversion particles that emit green light, there is also a wavelength conversion particle that emits yellow light. , Y can be shifted to the longer wavelength side by substituting a part of Gd for Gd, and yellow emission is possible, and among these, wavelength conversion particles capable of orange emission are also included. . there the wavelength converting particles emitting red, nitrogen-containing calcium aluminosilicate (CASN or SCASN) phosphor (e.g. _{(Sr, Ca) AlSiN 3:} Eu) is like . In addition, in the manganese-activated fluoride phosphor (a phosphor represented by general formula _{(I) A 2 [M 1} -a Mn a F 6] ( where the general formula (I), A , K, Li, Na, Rb, Cs, and NH ₄ and at least one element selected from the group consisting of Group 4 elements and Group 14 elements. , A satisfies 0 <a <0.2)). A typical example of the manganese-activated fluoride-based phosphor is a manganese-activated potassium fluorosilicate phosphor (for example, K ₂ SiF ₆ : Mn). There is.

  The reflective portions 42A to 42G include a base material and reflective particles dispersed in the base material. For the base material of the reflecting portion, for example, the material used as the translucent member 43 can be used. A white pigment can be used for the reflective particles. More specifically, as the white pigment, titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, barium titanate, barium sulfate, aluminum hydroxide, One of particles made of aluminum oxide, zirconium oxide, silicon oxide, or the like can be used alone, or two or more kinds of them can be used in combination. The shape of the particles of the white pigment can be appropriately selected and may be indefinite or crushed, but spherical is preferable from the viewpoint of fluidity. The particle size of the white pigment may be, for example, about 0.1 μm or more and 0.5 μm or less, but the smaller the particle size, the better for enhancing the effect of light reflection and coating. The content of the white pigment in the light-reflecting reflective member can be appropriately selected, but from the viewpoint of light reflectivity and viscosity in a liquid state, for example, 10 wt% or more and 70 wt% or less is preferable, and 20 wt% or more and 70 wt% or less. More preferably, 30 wt% or more and 60 wt% or less is even more preferable. In addition, "wt%" is a weight percentage and represents the ratio of the weight of the material to the total weight of the light-reflecting reflecting member.

  The reflecting portions 42A to 42G can be formed by arranging the base material in the above-described position and shape on the wavelength conversion member 41 by, for example, potting and curing the base material in an uncured state.

  The translucent member 43 can be formed using silicone resin, epoxy resin, phenol resin, polycarbonate resin, acrylic resin, or modified resin thereof. It can be glass. Among them, the silicone resin and the modified silicone resin are preferable because they are excellent in heat resistance and light resistance. Specific silicone resins include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin. The translucent member 43 may be configured by a single layer of one of these base materials or by laminating two or more of these base materials. Modified resins include hybrid resins.

  The translucent member 43 may contain various diffusing particles in the resin or glass. Examples of the diffusing particles include silicon oxide, aluminum oxide, zirconium oxide, zinc oxide and the like. As the diffusing particles, one of these may be used alone, or two or more of these may be used in combination. In particular, silicon oxide having a small coefficient of thermal expansion is preferable. Further, by using nanoparticles as the diffusing particles, it is possible to increase scattering of light emitted from the light emitting element and reduce the amount of the wavelength conversion member used. Note that the nanoparticles are particles having a particle size of 1 nm or more and 100 nm or less. Further, the “particle size” in the present specification is defined by D50, for example. Furthermore, the translucent member 43 may contain the 1 type or 2 or more types of wavelength conversion materials mentioned above.

(Protection member 50)
The protection member 50 covers the side surfaces of the light guide member 70 and the covering member 40, and is arranged on the base body 60. It is preferable that a groove or a step is provided along the outer periphery of the upper surface 65a of the base body 60, and a part of the protection member 50 is arranged in the groove or the step. As a result, the contact area between the protective member 50 and the base material 65 of the base 60 is increased, and the bonding strength between the protective member 50 and the base is increased.

  The protection member 50 covers the base material 65 of the base body 60, and particularly the side surface of the wavelength conversion member 41 of the coating member 40 is coated, so that the wavelength conversion member 41 is prevented from being deteriorated by moisture contained in the external environment. Suppress. Further, by covering the side of the structure on the base body 60, the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 are protected from the external environment. The protective member 50 preferably has light reflectivity. By having light reflectivity, the light emitted from the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 and the wavelength conversion member 41 perform wavelength conversion on the side surfaces of the light guide member 70 and the covering member 40. The reflected light is reflected and emitted to the outside of the light emitting device 101. For this reason, the utilization efficiency of light is improved and the division of light emitted from the light emitting device 101 is improved.

  The protective member 50 includes a base material and a white pigment dispersed in the base material, similarly to the reflecting portions 42A to 42G. The same material as the reflective portions 42A to 42G can be used for the base material and the white pigment.

(Method of manufacturing light emitting device 101)
The light emitting device 101 can be manufactured, for example, by the following method. First, the substrate 60 is prepared, and the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 are mounted on the first wiring 61. Next, the light guide member 70 that covers the upper surface of the first light emitting element, the upper surface of the second light emitting element, and the upper surface of the third light emitting element 30 is formed. After that, the separately prepared coating member 40 is placed on the light guide member 70. Then, the outer edges of the light guide member and the covering member are cut to separate the light guide member and the covering member into individual pieces. Next, the protective member 50 is formed in the gap formed by cutting the outer edges of the light guide member and the covering member. Then, the light emitting device 101 can be manufactured by cutting the base material 65 and the protective member 50 into individual pieces.

  As another method of manufacturing the light emitting device 101, first, the base 60 provided with the protective member 50 is prepared, and the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 are provided on the first wiring 61. Implement. Next, in the protective member 50, the light guide member 70 covers the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30. After that, the separately prepared coating member 40 is placed on the light guide member 70. Alternatively, in the protection member 50, the wavelength conversion member 41 is arranged on the light guide member 70, the reflection member 42 is formed on the wavelength conversion member 41, and the translucent member 43 is formed so as to cover the reflection member 42. You may. As a result, the light emitting device 101 is manufactured.

  The base body 60 provided with the protective member 50 may be divided into individual pieces in advance, or may be formed integrally with the lead frame to which the first wirings 61 of the plurality of light emitting devices 101 are connected. In this case, since the base material 65 and the protective member 50 of the base body 60 of the plurality of light emitting devices 101 are integrally molded, the base material 65 and the protective member 50 are cut after the covering member 40 is arranged, The light-emitting device 101 is manufactured by converting into

(Characteristics of the light emitting device 101)
The light emitting device 101 includes a first light emitting element and a second light emitting element having different peak wavelengths. Therefore, it is possible to reduce the wavelength band in which the emission intensity is reduced (also referred to as “spectral valley”) as compared with the case where there is one type of light emitting element, and for example, to emit white light with high color reproducibility. Is possible.

  In addition, the covering member 40 includes a wavelength conversion member and a reflecting member. The light emitted from the first light emitting element and the second light emitting element and the light wavelength-converted by the wavelength conversion member are randomly reflected to the base 60 side by the reflecting member, so that the mixing of these lights is promoted, which is good. It is possible to emit mixed light. For example, it becomes possible to emit a more uniform white color with high color reproducibility.

  In addition, the covering member has a third region overlapping between the first region and the second region in a top view, rather than a first region overlapping with the upper surface of the first light emitting element and a second region overlapping with the upper surface of the second light emitting element. The transmittance of the area is higher than that of the first area and the second area. In other words, the light transmittance is high in the region where the light source is not located, and the light transmittance immediately above the light emitting element is small. Therefore, the light emitting device 101 can suppress color unevenness.

  The distribution of the transmittance of the covering member can be realized by partially disposing the reflecting member included in the covering member. That is, the reflection member can suppress color unevenness. Therefore, it is possible to reduce the thickness of the covering member 40 and realize a side-view type light emitting device having a short depth in the Z-axis direction.

Such a light emitting device 101 can be suitably used, for example, as a backlight of a liquid crystal display device. A display device with high color reproducibility can be realized by using light with high color reproducibility as a backlight. Also,
(Other forms)
Various modifications can be made to the light emitting device of the present disclosure. FIG. 4 is a cross-sectional view of the light emitting device 102 including the reflecting member. The light emitting device 102 is different from the light emitting device 101 in that the light emitting device 102 includes a reflecting member 90 arranged on the upper surface 65 a of the base body 60.

  The reflecting member 90 is disposed on the upper surface 65a and is a side surface of the first wiring 61, the electrodes 13A and 13B of the first light emitting element 10, the electrodes 23A and 23B of the second light emitting element 20, and the electrodes 33A and 33B of the third light emitting element 30. Is covered. The reflecting member 90 covers the lower surface 12b of the first light emitting element 10, the lower surface 22b of the second light emitting element 20, and the lower surface 32b of the third light emitting element 30.

  The reflection member 90 can be made of, for example, a material in which a white pigment is added to the base material. As the base material and the white pigment, the materials exemplified as the base material and the white pigment of the reflection member 42 can be used.

  According to the light emitting device 102, since the reflecting member 90 is arranged on the upper surface 65a of the base body 60, the light emitted from the lower surface of each light emitting element and the light reflected to the base body 60 side by the reflecting member 42 are reflected by the reflecting member 90. Thus, the light can be reflected toward the opening 50a side of the protective member 50 and emitted to the outside. Therefore, the light extraction efficiency of the light emitting device 102 can be further improved.

  The light emitting device may not include the base body 60. FIG. 5 is a cross-sectional view of the light emitting device 103 without the base body 60. The light emitting device 103 is different from the light emitting device 102 in that the light emitting device 103 does not have the base body 60. Since the light emitting device 103 does not have the base body 60, the wiring 66 that electrically connects the first light emitting element 10, the second light emitting element 20, and the third light emitting element 30 is provided on the lower surface 90b of the reflecting member 90. According to the light emitting device 103, since the base 60 is not provided, the depth can be further shortened.

  The light emitting device of the present disclosure includes a backlight device of a liquid crystal display, various lighting devices, a large display, various display devices such as advertisements and destination guidance, a projector device, and an image in a digital video camera, a facsimile, a copying machine, a scanner, and the like. It can be used as a reader.

10 1st light emitting element 11, 21, 31, element substrate 11a, 12a, 21a, 22a, 31a, 32a, 41a, 43a upper surface 12, 22, 32 semiconductor laminated body 12b, 22b, 32b, lower surface 13A, 13B, 23A, 23B, 33A, 33B, electrode 20 2nd light emitting element 30 3rd light emitting element 40 covering member 41 wavelength conversion member 42 reflecting members 42A to 42G reflecting portion 43 translucent member 45a first region 45b second region 45c third region 45d Fourth region 45e Fifth region 50 Protective member 50a Opening 60 Base 61 First wiring 61t Convex portion 62 Second wiring 63 Via conductor 64 Insulating layer 65 Base material 65a Upper surface 65b Lower surface 65c to 65f Side surface 65g Recess 65h Via hole 66 Wiring 70 Conducting Optical member 70a Upper surface 90 Reflecting member 90b Lower surfaces 101, 102, 103 Light emitting device 101a Surface 101b bottom surface 101c~101f side

Claims (12)

A first light emitting element that emits light having a first peak wavelength of 430 nm or more and less than 490 nm;
A second light emitting element that emits light having a second peak wavelength of 490 nm or more and 570 nm or less;
The upper surface of the first light emitting element and the upper surface of the second light emitting element are continuously covered, and at least one of the light having the first peak wavelength and the light having the second peak wavelength is the first peak wavelength and the Between the wavelength conversion member that converts light having a third peak wavelength different from the second peak wavelength, the translucent member that covers the upper surface of the wavelength conversion member, and the wavelength conversion member and the translucent member. A reflective member located at, and a covering member including:
Equipped with
In a top view, the covering member includes a first region overlapping with an upper surface of the first light emitting element, a second region overlapping with an upper surface of the second light emitting element, the first region, and a space between the second regions. And a third region that overlaps, wherein the transmittance of the third region is higher than that of the first region and the second region.   The reflecting member includes a plurality of reflecting portions, and the plurality of reflecting portions are not located in a region between an upper surface of the first light emitting element and an upper surface of the second light emitting element in a top view. Item 2. The light emitting device according to item 1.   The light emitting device according to claim 2, wherein at least two reflecting portions are arranged on the upper surface of the first light emitting element and the upper surface of the second light emitting element in a top view.   The light emitting device according to claim 2, wherein the reflecting portion includes reflective particles.   The light emitting device according to claim 4, wherein the reflective particles are titanium oxide particles.   6. The light guide member continuously covers at least a part of the side surface of the first light emitting element and at least a part of the side surface of the second light emitting element. Light emitting device.   The light emitting device according to claim 1, wherein a side portion of the reflective member is in contact with at least one of the translucent member and the wavelength conversion member.   The light emitting device according to claim 1, further comprising a reflective protection member that covers at least side surfaces of the wavelength conversion member and the translucent member.   The light emitting device according to claim 1, further comprising a base on which the first light emitting element and the second light emitting element are mounted.   The light emitting device according to claim 1, wherein the third peak wavelength is 610 nm or more and 750 nm or less.   The light emitting device according to claim 1, further comprising a third light emitting element that emits light having the same peak wavelength as the first peak wavelength.   The light emitting device according to claim 1, wherein the transmittance of the first region is higher than the transmittance of the second region.

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