JP7460911B2 - Light emitting device and display using it - Google Patents

Description

This disclosure relates to a light-emitting device and a display using the same.

A light-emitting diode device has been developed that is equipped with R, G, and B LED chips and is capable of full-color emission (see, for example, Patent Document 1). Such light-emitting diode devices are soldered to a circuit board and are used, for example, as a white light source for liquid crystal display devices used in mobile phones, and the range of applications is expected to continue to expand in the future. This light-emitting diode device can be mounted on a circuit board in either a side-view or top-view direction, and it is described that it can be stably mounted on the circuit board.

Japanese Patent Application Publication No. 2006-24794

This embodiment provides a thin light-emitting device with little light leakage and a display using the same.

The light emitting device according to the present embodiment has a first lead, a second lead, a third lead, and a third lead in the X axis, the Y axis perpendicular to the X axis, and the Z axis perpendicular to the plane of the a package including a lead having at least four leads and a resin part, the X-axis direction being longer than the Y-axis direction and the Z-axis direction; a rectangular first light emitting element disposed on the first lead; A rectangular second light emitting element disposed on a first lead, a rectangular third light emitting element disposed on the second lead, and a first light emitting element electrically connecting the first lead and the first light emitting element. a conductive member, a second conductive member that is a conductive wire that electrically connects the fourth lead and the first light emitting element, and a conductive wire that electrically connects the first lead and the second light emitting element. A third conductive member, a fourth conductive member that is a conductive wire that electrically connects the second lead and the second light emitting element, and a conductive wire that electrically connects the first lead and the third light emitting element. and a sixth conductive member that is a conducting wire that electrically connects the third lead and the third light emitting element, the first light emitting element and the second light emitting element. , the third light emitting elements are arranged in the X-axis direction in this order, and one of the diagonals of each of the first light emitting element, the second light emitting element, and the third light emitting element is ±10 with respect to the X axis direction. The other one is within ±10 degrees with respect to the Y-axis direction, and the third conductive member, the fourth conductive member, and the fifth conductive member are within ±10 degrees with respect to the X-axis direction. The first light emitting element, the second light emitting element, and the third light emitting element are arranged on both sides of the diagonal line, which are within degrees of each other.

The display according to this embodiment includes a plurality of substrates arranged in the X-axis direction or the Y-axis direction, and a plurality of the light emitting devices arranged on each of the plurality of substrates.

According to this embodiment, it is possible to provide a thin light emitting device with little light leakage and a display using the same.

1 is a front view showing a configuration of a light emitting device according to a first embodiment. 1 is a plan view illustrating a configuration of a light emitting device according to a first embodiment. FIG. 2 is a bottom view showing the configuration of the light emitting device according to the first embodiment. FIG. 1 is a right side view showing the configuration of a light emitting device according to a first embodiment. FIG. 1 is a schematic front view showing the configuration of a display according to a first embodiment. 1 is an enlarged schematic perspective view showing a configuration of a display according to a first embodiment, as viewed obliquely from below. FIG. 2 is a front view showing an attached state of the light emitting device according to the first embodiment. FIG. 2 is a left side view showing a state in which the light emitting device according to the first embodiment is attached.

Hereinafter, a package, a light emitting device, and a manufacturing method thereof according to this embodiment will be described.

Note that the drawings referred to in the following description schematically show the embodiment, so the scale, spacing, positional relationship, etc. of each member may be exaggerated, or illustration of some members may be omitted. There are cases. Further, for example, in a plan view and a cross-sectional view thereof, the scale and spacing of each member may not match. In addition, in the following description, the same names and symbols basically indicate the same or homogeneous members, and detailed descriptions will be omitted as appropriate.

Furthermore, in the package, light emitting device, and manufacturing method thereof according to the embodiments, "top", "bottom", "left", "right", etc. are interchanged depending on the situation. In this specification, "upper", "lower", etc. indicate relative positions between constituent elements in the drawings referred to for explanation, and do not indicate absolute positions unless otherwise specified. Not what I intended.

[First embodiment]
The configuration of the light emitting device according to the first embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a front view showing the configuration of a light emitting device according to a first embodiment. FIG. 2 is a plan view showing the configuration of the light emitting device according to the first embodiment. FIG. 3 is a bottom view showing the configuration of the light emitting device according to the first embodiment. FIG. 4 is a right side view showing the configuration of the light emitting device according to the first embodiment.

Note that the relationship among the X-axis, Y-axis, and Z-axis is that the X-axis, the Y-axis perpendicular to the X-axis, and the Z-axis perpendicular to the plane of the X-axis and Y-axis. The X-axis, Y-axis, and Z-axis all have a plus (+) direction and a minus (-) direction, but unless otherwise specified, "X-axis direction" refers to the plus (+) X-axis direction. This includes both the minus (-) X-axis direction. Coordinate axes are shown in each figure of FIGS. 1 to 4, and for convenience, FIG. 1 is a front view of the light emitting device viewed in the negative direction of the Z axis, and FIG. 1 is a front view of the light emitting device viewed in the negative direction of the Y axis. 2 is a plan view, FIG. 3 is a bottom view when the light emitting device is viewed in the positive direction of the Y axis, and FIG. 4 is a right side view when the light emitting device is viewed in the negative direction of the X axis. The first to third light emitting elements may be collectively referred to as a light emitting element. Further, the first lead to the fourth lead may be collectively referred to as leads. The first inner lead part to the fourth inner lead part may be collectively referred to as an inner lead part. The first to fourth outer lead parts may be collectively referred to as an outer lead part. The first conductive member to the sixth conductive member may be collectively referred to as a conductive member.

The light emitting device 100 includes a plurality of light emitting elements 10 and a package 30 in which the plurality of light emitting elements 10 are arranged. The light emitting device 100 includes a lead 20 having at least a first lead 21, a second lead 22, a third lead 23, and a fourth lead 24, and a resin part 28, and the X-axis direction is parallel to the Y-axis direction and the Z-axis direction. A package 30 that is longer than the direction, a rectangular first light emitting element 11 disposed on the first lead 21 , a rectangular second light emitting element 12 disposed on the first lead 21 , and a rectangular second light emitting element 12 disposed on the second lead 22 . A rectangular third light emitting element 13, a first conductive member 41 that electrically connects the first lead 21 and the first light emitting element 11, and an electrically connecting fourth lead 24 and the first light emitting element 11. A second conductive member 42 that is a conductive wire, a third conductive member 43 that is a conductive wire that electrically connects the first lead 21 and the second light emitting element 12, and a second conductive member 43 that is a conductive wire that electrically connects the second lead 22 and the second light emitting element 12. a fourth conductive member 44 that is a conductive wire that electrically connects the first lead 21 and the third light emitting element 13; a fifth conductive member 45 that is a conductive wire that electrically connects the first lead 21 and the third light emitting element 13; 13, and a sixth conductive member 46 that is a conductive wire that electrically connects the conductive member 13.

The first light-emitting element 11, the second light-emitting element 12, and the third light-emitting element 13 are arranged in this order in the X-axis direction. One of the diagonals of the first light-emitting element 11, the second light-emitting element 12, and the third light-emitting element 13 is within ±10 degrees with respect to the X-axis direction, and the other is within ±10 degrees with respect to the Y-axis direction. The third conductive member 43, the fourth conductive member 44, and the fifth conductive member 45 are arranged on both sides of the diagonals of the first light-emitting element 11, the second light-emitting element 12, and the third light-emitting element 13, which are within ±10 degrees with respect to the X-axis direction.

The package 30 has a recess that opens in the +Z-axis direction. The package 30 has the first lead 21 to the fourth lead 24 arranged on the upper surface of the recess, and has a sidewall that extends from the upper surface of the recess in the +Z-axis direction. By setting the thickness of this sidewall defined in the Y-axis direction to a specified thickness, it is possible to reduce light leakage in the Y-axis direction.

Light from the light emitting device 100 is emitted in the +Z-axis direction.

As a result, the light emitting device 100 can provide a thin light emitting device with little light leakage. This is because the arrangement of the first light emitting element 11 and the like and the way of connecting the first conductive member 41 and the like in the package 30 long in the X-axis direction are arranged in a predetermined manner, thereby reducing light leakage in the Y-axis direction. In other words, by arranging one of the diagonals of each of the first light emitting element 11, the second light emitting element 12, and the third light emitting element 13 approximately parallel to the X-axis direction, a predetermined space is provided between the side wall of the package 30 and the first light emitting element 11 and the second light emitting element 12, and between the side wall of the package 30 and the second light emitting element 12 and the third light emitting element 13, and the joints of the first conductive member 41, the third conductive member 43, the fourth conductive member 44, and the fifth conductive member 45 are arranged in that space. This allows the package 30 to be short in the Y-axis direction and to be thin. In addition, the length of the wiring of the third conductive member 43, which is a conductor, can be shortened by arranging the joint portion of the third conductive member 43, which is a conductor, in a substantially triangular region formed by the side wall of the package 30, one side of the first light-emitting element 11, and one side of the second light-emitting element 12. In other words, when joining the third conductive member 43, which is a conductor, to the first lead 21, it is necessary to leave a predetermined space so that the capillary does not come into contact with the side wall of the package 30, the first light-emitting element 11, the second light-emitting element 12, etc., but by arranging the first light-emitting element 11, etc. in this manner, it is possible to provide the predetermined space. In addition, by making the other diagonal of the first light-emitting element 11 within ±10 degrees with respect to the Y-axis direction, even if the distance from the vertex of the first light-emitting element 11 to the side wall of the package 30 is shortened, the distance from the two sides extending from the vertex of the first light-emitting element 11 to the side wall of the package 30 can be increased, so that the amount of light from the first light-emitting element 11 in the Y-axis direction can be reduced, and by increasing the thickness of the side wall of the package 30, the light leaking to the outside from the side wall of the package 30 can be significantly reduced. In addition, even if the distance between the vertices of the first light-emitting element 11 and the second light-emitting element 12 facing each other is shortened, the first conductive member 41 and the third conductive member 43 can be joined to the area surrounded by the two sides extending from the vertex and the side wall of the package 30, so that the distance between the side walls of the recesses of the package 30 facing each other can be shortened, and thus a thinner package can be realized in the Y-axis direction. In this case, by increasing the thickness of the side wall of the recess of the package 30, the light leakage from the light-emitting element 10 in the Y-axis direction can be reduced. In addition, since the conductive member can be bonded to the lead at one location each within the area surrounded by the side surfaces of the two light-emitting elements and the side wall of the package, it is possible to ensure a wide area where the conductive member and the lead are bonded. In addition, by arranging the first light-emitting element 11 to the third light-emitting element 13 on both sides of the diagonal line, the thickness of the light-emitting device 100 in the Y-axis direction can be reduced. The light-emitting element 10 may be covered with a translucent member 50. The translucent member 50 may be filled in the recess of the package 30.

Note that while the explanation has been centered on the first light-emitting element 11, the same applies to the second light-emitting element 12 and the third light-emitting element 13.

It is preferable that the second conductive member 42, the fourth conductive member 44, the fifth conductive member 45, and the sixth conductive member 46 further include bumps. A resin portion 28 is provided between the first lead 21 and the fourth lead 24 to prevent short circuit. However, since the first lead 21, the fourth lead 24, and the resin portion 28 have significantly different coefficients of linear expansion, the package 30 is likely to warp. Due to this warpage, the second conductive member 42 spanning the first lead 21 and the fourth lead 24 is likely to be separated from the fourth lead 24 and short-circuited. Therefore, by arranging the bumps on the second conductive member 42, separation between the second conductive member 42 and the fourth lead 24 can be prevented. The reason for the fourth conductive member 44, the fifth conductive member 45, and the sixth conductive member 46 is the same as that for the second conductive member 42.

However, the first conductive member 41 and the third conductive member 43 that do not span between two leads may also be reinforced by providing bumps.

It is preferable that the first light-emitting element 11 emits red light, the second light-emitting element 12 emits green light, and the third light-emitting element 13 emits blue light. A full-color display can be achieved by using the three primary colors of light. Here, the second light-emitting element 12 that emits green light is disposed between the first light-emitting element 11 and the third light-emitting element 13. This is because when a plurality of light-emitting devices 100 are directly viewed in a display application, green appears brighter than blue or red light, even if the light quantity is the same. Therefore, the light quantity of the first light-emitting element 11 that emits red light and the third light-emitting element 13 that emits blue light is made higher than the light quantity of the second light-emitting element 12 that emits green light, so that light is more likely to leak from the sidewall of the recess of the package 30 in the Y-axis direction. Therefore, by making the thickness of the sidewall of the package 30 in the Y-axis direction where the first light-emitting element 11 is disposed and the thickness of the sidewall of the package 30 in the Y-axis direction where the third light-emitting element 13 is disposed thicker than the thickness of the sidewall of the package 30 in the Y-axis direction where the second light-emitting element 12 is disposed, deterioration of the sidewall of the package 30 can be suppressed and light leakage in the Y-axis direction can be reduced.

It is preferable that at least a part of the opposing sides of the first lead 21 and the second lead 22 is inclined at an angle of 20 degrees or more and 60 degrees or less with respect to the Y-axis direction. One side of the second light-emitting element 12 facing the first lead 21 is inclined at a predetermined angle with respect to the Y-axis direction. If the second light-emitting element 12 is approximately square, it is inclined at 45 degrees with respect to the Y-axis direction. Therefore, by making the opposing sides of the first lead 21 and the second lead 22 inclined at an angle of 40 degrees to 50 degrees, preferably about 45 degrees, with respect to the Y-axis direction, it is possible to ensure a wide joint between the fourth conductive member 44 and the second lead 22 and between the fifth conductive member 45 and the first lead 21.

The distance between the center of the first light emitting element 11 and the center of the second light emitting element 12 is preferably shorter than the distance between the center of the second light emitting element 12 and the center of the third light emitting element 13. This allows the outer diameter dimension of the package 30 in the X-axis direction to be reduced. Further, by leaving a predetermined distance between the first lead 21 and the second lead 22, it is possible to prevent a short circuit between the first lead 21 and the second lead 22. However, the distance between the center of the first light emitting element 11 and the center of the second light emitting element 12 can also be made longer than the distance between the center of the second light emitting element 12 and the center of the third light emitting element 13. The first conductive member 41 and the first inner lead part 21a, or the third conductive member 43 and the first inner lead part 21a, surrounded by the side wall of the package 30, the first light emitting element 11, and the second light emitting element. A wide bonding area can be secured. Further, the center line of the package 30 parallel to the Y-axis direction and the other diagonal line of the second light emitting element 12 may overlap or may be slightly shifted in the -X-axis direction. This is to ensure a predetermined area for the joint between the conductive member and the lead.

The first lead 21 has a first inner lead part 21a that is integrated with the resin part 28, and a first outer lead part 21b that extends outward from the resin part 28, and the second lead 22 is integrated with the resin part 28. The third lead 23 has a second inner lead part 22a that extends outward from the resin part 28, and a third inner lead part 23a that is integral with the resin part 28, and a second outer lead part 22b that extends outward from the resin part 28. The fourth lead 24 has a fourth inner lead part 24a that is integral with the resin part 28, and a fourth outer lead part 24b that extends outward from the resin part 28. It is preferable that the surface area of the first outer lead part 21b in the plane of the X-axis and the Z-axis is larger than the surface area of the second outer lead part 22b in the plane of the X-axis and the Z-axis. The surface area of the first lead 21 on which the first light emitting element 11 and the second light emitting element 12 are arranged is larger than the surface area of the second outer lead part 22b of the second lead 22 on which the third light emitting element 13 is arranged. It is possible to increase the surface area of the outer lead portion 21b and improve heat dissipation.

Furthermore, it is preferable that the surface area of the second outer lead portion 22b in the plane of the X-axis and Z-axis is larger than the surface area of the third outer lead portion 23b in the plane of the X-axis and Z-axis. The surface area of the second outer lead portion 22b of the second lead 22 on which the third light-emitting element 13 is arranged can be made larger than the surface area of the third outer lead portion 23b of the third lead 23 on which no light-emitting element is arranged, thereby improving heat dissipation.

It is preferable that the surface area of the third outer lead portion 23b and the surface area of the fourth outer lead portion 24b in the plane of the X-axis and Z-axis are the same. This allows the package 30 to be mounted stably.

The package 30 has a recess with an upper surface parallel to the plane of the X-axis and Y-axis, and side walls surrounding the upper surface and extending in the Z-axis direction. It is preferable that a part of the first inner lead portion 21a, a part of the second inner lead portion 22a, a part of the third inner lead portion 23a, and a part of the fourth inner lead portion 24a are exposed from the resin portion 28 on the upper surface. Both sides of the first outer lead portion 21b are exposed from the resin portion 28 and are bent in the manufacturing process. In contrast, only the upper surface of the first inner lead portion 21a is exposed from the resin portion 28, and the lower surface is embedded in the resin portion 28. The second inner lead portion 22a, the third inner lead portion 23a, and the fourth inner lead portion 24a are also intended to be similar to the first inner lead portion 21a.

It is preferable that the first outer lead part 21b, the second outer lead part 22b, the third outer lead part 23b, and the fourth outer lead part 24b are arranged inside the side wall of the resin part 28 in the Y-axis direction. As a result, when the package 30 is viewed in the −Z-axis direction, the first outer lead portion 21b, the second outer lead portion 22b, the third outer lead portion 23b, and the fourth outer lead portion 24b are not visible. . The fact that the first outer lead portion 21b and the like are arranged inside the side wall of the resin portion 28 in the Y-axis direction means that when the package 30 is viewed in the −Z-axis direction, the outer side wall surface of the resin portion 28 This means that the first outer lead part 21b and the like are flush with each other, or the first outer lead part 21b and the like are arranged inside the outer side wall surface of the resin part 28 in the +Y-axis direction. Again, "flush" includes 100 μm or less, preferably 50 μm or less.

When the side wall of the recess of the package 30 is viewed from the Z-axis direction, it is preferably long in the X-axis direction, approximately elliptical, or approximately hexagonal to dodecagonal. By having a predetermined shape, it is possible to reduce light leakage from the first light emitting element 11 and the like in the Y-axis direction. In particular, by making the side walls of the recess of the package 30 closer to the first light emitting element 11 and the third light emitting element 13 thicker than the side walls of the recess of the package 30 closer to the second light emitting element 12, Even if the direction is made thinner, light leakage can be reduced.

When the recess of the package 30 is viewed from the Z-axis direction, the shape of the third inner lead portion 23a and the fourth inner lead portion 24a exposed from the resin portion 28 is preferably one of a substantially semicircular, triangular, rectangular, and pentagonal shape. By making them into a predetermined shape, it is possible to reduce light leakage from the first light-emitting element 11 and the like in the Y-axis direction. In particular, by making the sidewall of the recess of the package 30 closer to the first light-emitting element 11 and the third light-emitting element 13 thicker than the sidewall of the recess of the package 30 closer to the second light-emitting element 12, it is possible to reduce light leakage even if the package 30 is made thinner in the Y-axis direction.

When the recess of the package 30 is viewed from the Z-axis direction, the inner surface of the side wall of the recess has a straight line extending in the X-axis direction, and both ends of the straight line are connected to the first light emitting element 11 and the third light emitting element. 13 preferably overlap each other in the Y-axis direction. This allows the area of the upper surface of the recess to be increased.

It is preferable that the opening is expanded so that the angle of the inner surface of the side wall with respect to the upper surface of the recess is between 90 degrees and 110 degrees. By setting the inclination angle of the side wall within a predetermined range, the thickness of the side wall can be increased, thereby reducing light leakage in the Y-axis direction.

Next, a display using a plurality of light emitting devices according to the first embodiment will be described. FIG. 5 is a schematic front view showing the configuration of the display according to the first embodiment. FIG. 6 is an enlarged schematic perspective view of the configuration of the display according to the first embodiment, viewed diagonally from below. FIG. 7 is a front view showing the attached state of the light emitting device according to the first embodiment. FIG. 8 is a left side view showing the attached state of the light emitting device according to the first embodiment.

The display 200 according to the first embodiment has a plurality of substrates 110 arranged in the X-axis direction or the Y-axis direction, and a plurality of light-emitting devices 100 according to the first embodiment arranged on each of the plurality of substrates 110. By using a plurality of substrates, it is possible to provide gaps between the plurality of substrates. This makes it possible to reduce the sense of oppression felt by the display 200. In addition, a clear image can be displayed by reducing the light leakage from the light-emitting devices 100 in the Y-axis direction. It is also possible to reduce the weight of the display 200.

When the display 200 is viewed from a specified distance away, the -Y axis direction is the top, the +Y axis direction is the bottom, the -X axis direction is the right side, the +X axis direction is the left side, the +Z axis direction is the front side, and the -Z axis direction is the rear side.

The display 200 is configured so that an image can be viewed in the planar direction of the X-axis and Y-axis, and the substrate 110 has a sheet surface in the planar direction of the X-axis and Z-axis, and it is preferable that the light-emitting device 100 is disposed on the sheet surface of the substrate 110 in the planar direction of the X-axis and Z-axis. This makes it possible to view the back side of the display 200 when the display 200 is not lit and viewed in the Z-axis direction. Conversely, for example, when the display 200 is disposed on the wall of a building, the outside can be viewed from inside the building through the gaps between the multiple substrates 110.

The bottom surface of the light emitting device 100 is mounted so as to face the surface below the display 200, that is, the sheet surface in the +Y-axis direction with respect to the sheet surface on the X-axis and Z-axis planes of the substrate 110. Thereby, the light emitted from the light emitting device 100 in the +Z-axis direction can be visually recognized without being blocked by the substrate 110.

Among the plurality of substrates 110, the distance between one substrate 110 and another substrate 110 adjacent to each other in the Y-axis direction is preferably 1.5 times or more and 5 times or less the thickness of the light emitting device 100. By setting the intervals between the substrates 110 at a predetermined interval, it is possible to visually recognize the back surface of the display 200 while maintaining the clarity when displaying an image as a display. Further, among the plurality of light emitting devices 100, the distance between one light emitting device 100 and another light emitting device 100 adjacent to each other in the X-axis direction is The distance is preferably the same as or 0.5 times or more and 1.5 times or less. As a result, the dot spacing of the light emitting device 100 serving as a pixel can be set within a predetermined range, and a clearer image can be displayed.

Next, each part of the light emitting device 100 will be described in detail.

(Light Emitting Element)
The first light emitting element to the third light emitting element are described as the light emitting element 10. The light emitting color and material of the light emitting element are appropriately read as the first light emitting element, the second light emitting element, and the third light emitting element. The light emitting element can be suitably used as a semiconductor light emitting element such as an LED or an LD. Such a semiconductor light emitting element is suitably formed by stacking semiconductors such as ZnS, SiC, GaN, GaP, InN, AlN, ZnSe, GaAsP, GaAlAs, InGaN, GaAlN, AlInGaP, and AlInGaN on a substrate by a liquid phase growth method, a HDVPE method, or a MOCVD method. As the semiconductor material, a gallium nitride semiconductor represented by In _x Al _y Ga _1-X-Y N (0≦X, 0≦Y, X+Y<1) can be more suitably used because the emission wavelength can be selected from various wavelengths from ultraviolet light to infrared light by selecting the degree of mixed crystal.

The size of the light-emitting element is not particularly important, but is determined taking into consideration the luminous flux and compactness. The light-emitting element may be rectangular, such as a square or a rectangle, and for example, each side is preferably 150 μm to 600 μm, and particularly preferably 200 μm to 400 μm.

The light-emitting element is disposed on the first lead and the second lead provided on the upper surface (the surface parallel to the plane of the X-axis and Y-axis) of the recess of the package. The positive and negative electrodes (anode and cathode) of the light-emitting element are electrically connected to the corresponding first to fourth leads using bonding conductors made of Au, Ag, Cu, Al, or the like. However, the first conductive member 41 does not have to be a conductor, and may be a conductive member such as solder or silver paste. The conductor is a so-called wire, and is preferably φ10 to φ50 μm.

Further, although three light emitting elements are mounted in one package, four or more light emitting elements can also be mounted. The plurality of light emitting elements may emit the same color or different colors.

(package)
The package 30 includes a first lead 21 to a fourth lead 24 and a resin part 28. The package 30 has the first lead 21 to the fourth lead 24 and the resin part 28 integrally molded. The package has a recess opening in the Z-axis direction, and the first to fourth outer lead parts are arranged on the bottom surface, which is a plane parallel to the plane of the X-axis and the Z-axis. The outer shape of the package has a substantially rectangular parallelepiped shape that is flattened in the Y-axis direction, which is the thickness direction, and is suitable for side-view mounting, which is suitably used as a light source for a backlight of a display. The first lead is a common terminal from the first light emitting element to the third light emitting element, and the second lead to the fourth lead are connected to the first light emitting element to the third light emitting element, respectively, and the polarity is different from that of the first lead. It has the following.

(Lead)
The lead 20 is partially embedded in the resin part 28 and has an inner lead part and an outer lead part for mounting the light emitting element 10. The inner lead portion refers to a portion that is buried in the resin portion or is partially buried in the resin portion even if the surface is exposed. On the other hand, the outer lead portion is not embedded in the resin portion. Here, the outer lead portion protrudes from the resin portion on the bottom side of the package and is bent toward the back side of the package. This outer lead portion is mounted on the board using a conductive material such as solder.

The lead is formed using a metal that is plate-shaped in a plan view, and may be flat, corrugated, or uneven. The thickness may be uniform, or may be partially thicker or thinner. The side of the lead may be flat, corrugated, or uneven.

The inner lead portion is provided on the upper surface of the recess of the resin portion and is exposed from the resin portion. On the upper surface of the recess, the first inner lead portion to the fourth inner lead portion are separated into four portions, and the first inner lead portion is used as the positive electrode and the second inner lead portion to the fourth inner lead portion are used as the negative electrode, but the first inner lead portion may be used as the negative electrode and the second inner lead portion to the fourth inner lead portion as the positive electrode. The light-emitting element is bonded to the inner lead portion with the semiconductor layer insulated from the inner lead portion. However, the first light-emitting element may be bonded to the inner lead portion while being electrically connected to the semiconductor layer. In addition, the positive and negative pad electrodes of the light-emitting element are electrically connected to the inner lead portion of the polarity corresponding to each pad electrode using a conductor such as a bonding wire.

The outer lead portion is formed continuous with the corresponding inner lead portion, protrudes from the bottom surface of the resin portion, and is bent so as to extend along the bottom surface of the resin portion toward the rear side (-Z direction). The third outer lead portion and the fourth outer lead portion are further bent so as to extend upward (+Y axis direction) along the left and right side surfaces of the resin portion.

The material constituting the lead is not particularly limited, but it is preferable to form it from a material with a relatively large thermal conductivity. By forming it from such a material, the heat generated by the light emitting element can be efficiently dissipated to the outside through the outer lead portion. The material constituting the lead is preferably one that has a thermal conductivity of about 200 W/(m·K) or more, has a relatively large mechanical strength, or is easy to stamp or etch. Specific examples include metals such as copper, aluminum, gold, silver, tungsten, iron, and nickel, or alloys such as iron-nickel alloys and phosphor bronze. In addition, it is preferable that the surface exposed on the upper surface of the recess of the inner lead portion is coated with a reflective plating such as Ag, Al, or Au that has good light reflectivity in order to efficiently extract light from the mounted light emitting element. In order to increase the adhesion between the reflective plating and the base material of the lead, it is preferable to place an underlayer such as Ni, Pd, Rh, or Ru.

(Resin part)
The resin portion 28 is provided to surround the inner lead portion and is a package body for supporting the leads. An outer lead portion that is continuous with the inner lead portion protrudes from the bottom surface of the resin portion. The outer lead portion is provided to bend and fit along the bottom surface and/or side surface of the resin portion.

The resin part has a recess that opens to the front side (+Z-axis direction) of the light emitting device. A gate mark is formed on the back surface of the resin part 28, which is the mark of the gate through which the resin material is injected into the mold when the resin part is formed by the injection molding method.

The resin portion is made of a material that is made light reflective by adding particles of a light-reflective substance to a translucent resin, and in the recess, it also functions as a reflective member that reflects light from the light-emitting element and efficiently emits it in the forward direction.

The recess has a horizontally elongated opening that is long in the X-axis direction when viewed from the front. More specifically, the opening has an octagonal shape with two long sides that face each other and extend in the X-axis direction when viewed from the front, four sides that extend from the two long sides and are inclined at a predetermined angle in the Y-axis direction from the X-axis direction, and two sides that extend in the Y-axis direction. The recess is also surrounded by a first side wall and a second side wall that are arranged opposite each other in the thickness direction (Y-axis direction) of the light-emitting device, and a third side wall and a fourth side wall that are arranged opposite each other in the width direction (X-axis direction) of the light-emitting device.

Here, the first and second side walls are formed thicker than the third and fourth side walls. This is because the distance from the first and second side walls to the light emitting element is closer than the distance from the third and fourth side walls to the light emitting element. This makes it possible to reduce light leakage from the package in the Y-axis direction.

The sidewalls also have inclined inner surfaces so that the width of the recess increases from the top surface of the recess toward the opening (in the +Z-axis direction). As a result, light emitted from the light-emitting element and propagating laterally is reflected toward the front by these inclined inner surfaces. However, in order to reduce the size of the package and light leakage, the angle of inclination may be made smaller, or even the sidewalls may be made nearly vertical without any inclination.

The resin material used for the resin part is preferably a thermoplastic resin, a thermosetting resin, or a mixture thereof, which has good transparency for the wavelength of light emitted by the light emitting element. Specific materials for the resin part include, for example, silicone resin, silicone modified resin, epoxy resin, epoxy modified resin, urea resin, phenol resin, polycarbonate resin, acrylic resin, polymethylpentene resin, polynorbornene resin, and polyphthalamine resin. , polyphthalamide resin, liquid crystal polymer, or a hybrid resin containing one or more of these resins. Among these, polyphthalamide resin is preferred because it is inexpensive while maintaining heat resistance and light resistance.

As the light-reflecting substance to be contained in the resin portion, it is preferable to use particles of a material that has a large refractive index difference with the above-mentioned resin material and has good light transmissivity. Such a light-reflecting substance has a refractive index of, for example, 1.8 or more, and in order to efficiently scatter light and obtain high light extraction efficiency, it is preferably 2.0 or more, and more preferably 2.5 or more. The refractive index difference with the resin material is, for example, 0.4 or more, and in order to efficiently scatter light and obtain high light extraction efficiency, it is preferably 0.7 or more, and more preferably 0.9 or more. In addition, the average particle size of the particles of the light-reflecting substance is preferably 0.08 μm or more and 5 μm or less, more preferably 0.1 μm or more and 3 μm or less, and even more preferably 0.3 μm or more and 0.8 μm or less, so that the light scattering effect can be obtained with high efficiency.

In this specification, the average particle size of particles such as light-reflecting substances and wavelength conversion substances is based on observations using an electron microscope. For particles, a fixed-direction diameter is used, which is measured over a length in a fixed axial direction, and a number standard (number distribution) is used to measure the particle size using an electron microscope (SEM, TEM).

As the light-reflective material, specifically, particles of white pigments such as _TiO2 (titanium oxide), _ZrO2 (zirconium oxide), MgO (magnesium oxide), _MgCO3 (magnesium carbonate), Mg(OH) ₂ (magnesium hydroxide), _CaCO3 (calcium carbonate), Ca(OH) ₂ (calcium hydroxide), _CaSiO3 (calcium silicate), ZnO (zinc oxide), _BaTiO3 (barium titanate), and _Al2O3 (aluminum oxide) can be used. Among them, _TiO2 is preferable _because it is relatively stable against moisture and has a high refractive index and excellent thermal conductivity.

In addition, in order to obtain better reflectivity, it is preferable to use TiO ₂ as a light-reflecting substance when the light emitted by the light-emitting element is visible light of 420 nm or more, and in the case of ultraviolet light, it is preferable to use TiO 2 as a light-reflecting substance. It is preferable to use Al ₂ O ₃ as the sexual substance.

The resin material also contains a light-reflecting substance to the extent that moldability is not impaired when forming the shape of the package. For this reason, the content of the light-reflecting substance contained in the resin portion is preferably 10% by mass or more and 80% by mass or less, and more preferably 20% by mass or more and 60% by mass or less.

Here, as the thickness of the resin part containing the light-reflecting substance within the above range decreases, the light-reflectivity decreases and the amount of incident light transmitted increases. Therefore, the reflective film may be provided only on the outer surface of the first side wall, or may be provided so as to cover the entire outer surface of the side wall of the resin portion surrounding the recess. As the reflective film, a resin layer containing particles of a light reflective substance can be used.

(Translucent member)
The light-transmitting member 50 is a member that is provided to fill the recess of the package and seals the light emitting element mounted on the upper surface of the recess. As the light-transmitting member, it is preferable to use a material that has good light-transmitting properties for the wavelength of light emitted by the light-emitting element, and as the sealing member, having good weather resistance, light resistance, and heat resistance. As such a material, the same resin material as the resin part 28 described above, glass, etc. can be used, but it is preferable to use phenyl silicone. Further, the light-transmitting member may contain a light-diffusing substance, and the same light-reflecting substance as described above can be used.

The translucent member may also contain a wavelength conversion material (phosphor) that converts the light emitted by the light-emitting element into light of a different wavelength. For example, a light-emitting device capable of displaying full color can be provided by dividing the translucent member into two or more sections, configuring the light-emitting element to emit blue light, and configuring the wavelength conversion material to convert part of the blue light into green light, yellow light, or red light.

Furthermore, as the wavelength conversion substance (phosphor), those known in the art can be used. For example, a YAG (yttrium aluminum garnet) based phosphor activated by cerium that emits green to yellow light, a LAG (lutetium aluminum garnet) based phosphor activated by cerium that emits green light, and a cerium activated LAG (lutetium aluminum garnet) phosphor that emits green to red light. Nitrogen-containing calcium aluminosilicate (CaO-Al ₂ O ₃ -SiO ₂ )-based phosphor activated with europium and/or chromium that emits light, silicate ((Sr,Ba) ₂ activated with europium that emits blue to red light) SiO ₄ )-based phosphors, green-emitting β-sialon phosphors, red-emitting CASN-based phosphors represented by CaAlSiN ₃ :Eu, or (Sr,Ca)AlSiN ₃ :Eu-based SCASN phosphors, etc. Nitride-based phosphors, KSF (K ₂ SiF ₆ :Mn)-based phosphors that emit red light, KSAF-based phosphors (e.g., K ₂ (Si,Al)F ₆ :Mn), or MGF-based phosphors (e.g., Examples include fluoride-based phosphors such as 3.5MgO.0.5MgF ₂ .GeO ₂ :Mn) and sulfide-based phosphors that emit red light. In addition, a phosphor having a perovskite structure (for example, CsPb (F, Cl, Br, I) ₃ ), a quantum dot phosphor (for example, CdSe, InP, AgInS ₂ or AgInSe ₂ ), or the like can be used.

(substrate)
A substrate 110 on which a plurality of light emitting devices are mounted is provided with predetermined wiring and is formed so as to be electrically connected to the leads of the package. The substrate is preferably in the form of a sheet with a predetermined width, and wiring may be arranged on one surface, or wiring may be arranged on both surfaces via vias or the like. A metal material can be used for the wiring and vias. The leads of the light emitting device and the substrate are electrically connected using a conductive member. The light emitting device is arranged so that its light emitting surface is perpendicular to the surface of the substrate on which the light emitting device is mounted. This is because if the light emitting surface of the light emitting device is tilted with respect to the surface of the substrate on which the light emitting device is mounted, the display will appear dark. Further, it is preferable that the conductive members and leads connecting the light emitting device and the substrate are arranged so that they cannot be seen when the display is viewed from the front. In other words, the distance between the light emitting device and the substrate is preferably 300 μm or less, preferably 100 μm or less, and more preferably no gap.

The base material forming the substrate may be made of an insulating resin material such as phenolic resin, epoxy resin, polyimide resin, polyethylene terephthalate, polyethylene naphthalate, silicone resin, bismaleimide triazine resin, polyphthalamide, etc., or may be a metal member with an insulating material formed in a layer on its surface. The base material may be a rigid or flexible substrate, or may be a laminate of multiple substrates.

The protection member protects the wiring. This protective member can be made of phenyl silicone resin, dimethyl silicone resin, or the like. Furthermore, a pigment may be added to the protective member in order to make it opaque. It is preferable that the substrate and the protective member contain carbon or the like to have a dark color or a black color. This is to provide contrast when the light emitting device is not lit.

For the display, a plurality of substrates each having a plurality of light emitting devices mounted thereon are prepared and arranged in parallel to the X-axis direction. The length of the substrate is not particularly limited and is determined depending on the size of the display.

[Method for manufacturing light emitting device]
Next, a method for manufacturing the light emitting device will be described.

A package having a predetermined shape is prepared. The package is preferably in a state before the leads are separated from the lead frame, but may be in a state after the leads are separated. Then, the first light-emitting element and the second light-emitting element are mounted on the first inner lead portion so that they face in a predetermined direction. The first light-emitting element and the second light-emitting element are bonded using die-bond paste. At this time, if the first light-emitting element has electrodes on the top and bottom, the first lead and the first light-emitting element are bonded using a conductive die-bond paste, but if the first light-emitting element has electrodes only on the top surface like the second light-emitting element, etc., they may be bonded with an insulating die-bond paste. Then, the third light-emitting element is mounted on the second inner lead portion. However, the order of the first light-emitting element to the third light-emitting element is not particularly important.

Next, the first light-emitting element is electrically connected to the first lead and the fourth lead. The first light-emitting element is connected to the fourth lead using a second conductive member, which is a conductor. The second conductive member is connected by bonding to the electrode of the first light-emitting element and then to the fourth lead. Similarly, the second light-emitting element and the third light-emitting element are connected to the first lead, the second lead, and the third lead, respectively.

After that, bumps are provided on the second conductive member, the fourth conductive member, the fifth conductive member, and the sixth conductive member to reinforce the bonding. However, bumps may be provided on the first conductive member and the third conductive member. It is preferable to provide the bump on the side connected to the lead.

Then, the recess of the package is filled with a translucent material so as to cover the light-emitting element. The translucent material can be molded by dripping the liquid translucent material using a syringe or the like and heating it to harden.

Finally, the leads are cut from the lead frame and bent in a predetermined direction to form a light emitting device.

These light-emitting devices are mounted on a substrate using a conductive material. A display can be created by preparing multiple substrates, each with multiple light-emitting devices mounted on it, and arranging these substrates in a specified frame.

Next, a light emitting device according to an example will be described with reference to FIGS. 1 to 4. In the light emitting device according to the example, description of parts that overlap with those described in the light emitting device according to the first embodiment may be omitted.

In the light emitting device of Example 1, the package can have outer diameter dimensions of 3.2 mm in the X-axis direction, 1.35 mm in the Y-axis direction, and 1.5 mm in the Z-axis direction. In this case, the thickness of the thin parts (long parts parallel to the X-axis direction) of the first and second side walls is 0.3 mm, and the height of the first and second side walls from the inner lead parts is 0.4 mm, so that the recess in the Y-axis direction can have a gap of 0.6 to 0.75 mm. The distance between the first and second inner lead parts is 0.18 mm, the distance between the first and fourth inner lead parts is 0.18 mm, and the distance between the second and third inner lead parts is 0.125 mm. The thickness of the lead is 0.125 mm.

The width of the first outer lead portion is 0.45 mm, the width of the second outer lead portion is 0.30 mm, and the widths of the third outer lead portion and the fourth outer lead portion are 0.25 mm.

The first light emitting element emits red light, has a square shape with one side of 315 μm, and a height of 150 μm. The second light emitting element emits green light, has a square shape with one side of 320 μm, and a height of 120 μm. The third light emitting element emits blue light, has a square shape with one side of 230 μm, and a height of 120 μm.

The lead material is an alloy of copper and iron, and the surface of the inner lead part is silver plated. The resin part uses polyphthalamide resin and contains titanium oxide. The resin portion has a reflectance of 85% or more when irradiated with light of 470 nm. A wire with a diameter of 25 μm is used as the conductive member. The translucent member uses phenyl silicone resin having translucency. The translucent member contains filler.

This light emitting device was subjected to a light leakage test, a reflow resistance test, a UV peeling resistance test, a migration resistance test, etc., all of which yielded good results. In the heat resistance test, 70% water absorption at 30°C and 95% water absorption at 65°C were also good.

Above, the light emitting device, the package, and the manufacturing method thereof according to the present invention have been specifically explained using the mode for carrying out the invention and examples thereof, but the gist of the present invention is not limited to these descriptions. and should be interpreted broadly based on the description of the claims. Furthermore, it goes without saying that various changes and modifications based on these descriptions are also included within the spirit of the present invention.

The light-emitting device according to this embodiment can be used as a variety of light sources, including large displays, various lighting fixtures, and various display devices for advertising and destination guidance.

10 Light emitting element 11 First light emitting element 12 Second light emitting element 13 Third light emitting element 20 Lead 21 First lead 21a First inner lead part 21b First outer lead part 22 Second lead 22a Second inner lead part 22b Second outer Lead part 23 Third lead 23a Third inner lead part 23b Third outer lead part 24 Fourth lead 24a Fourth inner lead part 24b Fourth outer lead part 28 Resin part 30 Package 41 First conductive member 42 Second conductive member 43 Third conductive member 44 Fourth conductive member 45 Fifth conductive member 46 Sixth conductive member 50 Transparent member 100 Light emitting device 110 Substrate

Claims (13)

In the X axis, the Y axis perpendicular to the X axis, and the Z axis perpendicular to the plane of the X axis and Y axis,
A package including a lead having at least a first lead, a second lead, a third lead, and a fourth lead, and a resin part, the X-axis direction being longer than the Y-axis direction and the Z-axis direction;
a rectangular first light emitting element disposed on the first lead;
a rectangular second light emitting element disposed on the first lead;
a rectangular third light emitting element disposed on the second lead;
a first conductive member that electrically connects the first lead and the first light emitting element;
a second conductive member that is a conductive wire that electrically connects the fourth lead and the first light emitting element;
a third conductive member that is a conductive wire that electrically connects the first lead and the second light emitting element;
a fourth conductive member that is a conductive wire that electrically connects the second lead and the second light emitting element;
a fifth conductive member that is a conductive wire that electrically connects the first lead and the third light emitting element;
at least a sixth conductive member that is a conductive wire that electrically connects the third lead and the third light emitting element;
The first light emitting element, the second light emitting element, and the third light emitting element are arranged in this order in the X-axis direction,
One of the diagonals of each of the first light emitting element, the second light emitting element, and the third light emitting element is within ±10 degrees with respect to the X-axis direction, and the other one is within ±10 degrees with respect to the Y-axis direction. Within ±10 degrees,
The third conductive member, the fourth conductive member, and the fifth conductive member are within ±10 degrees with respect to the X-axis direction of the first light emitting element, the second light emitting element, and the third light emitting element, respectively. are placed on both sides of the diagonal line ,
The package has a recess, and when the recess is viewed from the Z-axis direction, the inner surface of the side wall of the recess has a straight portion extending in the X-axis direction, and both ends of the straight portion are connected to the first A light emitting device in which a light emitting element and the third light emitting element each overlap in the Y-axis direction . The light emitting device according to claim 1, wherein the second conductive member, the fourth conductive member, the fifth conductive member, and the sixth conductive member further include bumps. 3. The light emitting device according to claim 1, wherein the first light emitting element emits red light, the second light emitting element emits green light, and the third light emitting element emits blue light. 4. The light emitting device according to claim 1, wherein at least part of opposing sides of the first lead and the second lead are at least 20 degrees and at most 60 degrees with respect to the Y-axis direction. The distance between the center of the first light emitting element and the center of the second light emitting element is shorter than the distance between the center of the second light emitting element and the center of the third light emitting element. The light emitting device according to item 1. The first lead has a first inner lead part that is integrated with the resin part, and a first outer lead part that extends outward from the resin part,
The second lead has a second inner lead part that is integrated with the resin part, and a second outer lead part that extends outward from the resin part,
The third lead has a third inner lead part that is integral with the resin part, and a third outer lead part that extends outward from the resin part,
The fourth lead has a fourth inner lead part that is integral with the resin part, and a fourth outer lead part that extends outward from the resin part,
The surface area of the first outer lead portion in the plane of the X-axis and the Z-axis is larger than the surface area of the second outer lead portion in the plane of the X-axis and the Z-axis. The light emitting device described. The light emitting device of claim 6, wherein the package has a recess having a top surface parallel to the plane of the X-axis and Y-axis and a sidewall surrounding the top surface and extending in the Z-axis direction, and the top surface is such that a portion of the first inner lead portion, a portion of the second inner lead portion, a portion of the third inner lead portion, and a portion of the fourth inner lead portion are exposed from the resin portion. The light emitting device according to claim 7, wherein the first outer lead portion, the second outer lead portion, the third outer lead portion, and the fourth outer lead portion are disposed inward in the Y-axis direction from the side wall of the resin portion. The light-emitting device according to claim 7 or 8, wherein the side wall of the recess of the package is elongated in the X-axis direction, and has a shape that is either substantially elliptical or substantially hexagonal to substantially dodecagonal, when viewed from the Z-axis direction. When looking at the recessed part of the package from the Z-axis direction, the third inner lead part and the fourth inner lead part exposed from the resin part have a substantially semicircular, triangular, square, or pentagonal shape. The light emitting device according to any one of claims 7 to 9. 11. The light emitting device according to claim 7, wherein the opening expands such that an angle of the inner surface of the side wall with respect to the upper surface of the recess is equal to or greater than 90 degrees and equal to or less than 110 degrees. A plurality of substrates arranged in the X-axis direction or the Y-axis direction;
A display comprising: a plurality of light-emitting devices according to claim 1 arranged on each of the plurality of substrates;
The display is configured so that an image can be viewed in a plane direction of an X axis and a Y axis,
the substrate has a sheet surface in a plane direction of the X-axis and the Z-axis,
A display, in which the light emitting device is disposed on a sheet surface having a plane extending in the X-axis and Z-axis directions of the substrate. 13. The display according to claim 12 , wherein a distance between one substrate and another adjacent substrate among the plurality of substrates is 1.5 times or more and 5 times or less the thickness of the light emitting device.

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