This application claims priority to Japanese Patent Application No. 2021-162285, filed on Sep. 30, 2021, Japanese Patent Application No. 2022-024239 filed on Feb. 18, 2022 and Japanese Patent Application No. 2022-083491 filed on May 23, 2022, the disclosures of which are hereby incorporated by reference in their entirety.
The present disclosure relates to a light-emitting device and a manufacturing method of the light-emitting device.
As alight-emitting device including alight-emitting diode (LED), a shell-shaped (lamp-type) light-emitting device including leads, a surface mount light-emitting device, and the like are known. Because lamp-type light-emitting devices have high light distribution in a frontward direction, such light-emitting devices are preferably used for large display devices, such as an LED display device, in which light-emitting devices are arranged in a matrix pattern as pixels.
Further, Japanese Patent Publication No. H10-261821 describes a surface-mountable light-emitting device including a lens on a light-emitting surface of the light-emitting device.
One non-limiting exemplary embodiment of the present disclosure provides a light-emitting device that can reduce deterioration of characteristics of the light-emitting device by using a waterproof resin.
A light-emitting device according to one embodiment of the present disclosure includes a resin package including a plurality of leads and a resin member fixing at least a part of the plurality of leads, a plurality of light-emitting elements, and a mold resin portion. The resin package is provided with a primary surface, a back surface positioned opposite to the primary surface, and a lateral surface portion positioned between the primary surface and the back surface. Each of the plurality of leads includes an exposed region exposed at the primary surface from the resin member. The plurality of light-emitting elements include a first light-emitting element, a second light-emitting element, and a third light-emitting element. Each of the plurality of light-emitting elements is disposed in the exposed region of one of the plurality of leads. The mold resin portion includes a base portion sealing the plurality of light-emitting elements and a plurality of lens portions positioned above the base portion and integrally formed with the base portion. The plurality of lens portions include a first lens portion overlapping, in a plan view, the first light-emitting element, a second lens portion overlapping, in a plan view, the second light-emitting element, and a third lens portion overlapping, in a plan view, the third light-emitting element. The base portion includes an upper surface positioned above the primary surface of the resin package, and a lateral surface portion of the base portion covering a part of the lateral surface portion of the resin package in a direction from the upper surface of the base portion toward the back surface of the resin package. In a cross-sectional view, a first point is positioned closer to the plurality of lens portions than a second point, and the second point is positioned outward of a third point. The first point is an outermost point of the upper surface of the base portion, the second point is an outermost point of the lateral surface portion of the base portion, and the third point is an outermost point where the lateral surface portion of the resin package and the lateral surface portion of the base portion come into contact. In a cross-sectional view, the first light-emitting element is positioned closer to the back surface of the resin package than the first point and is positioned above the second point.
A light-emitting device according to one embodiment of the present disclosure includes a resin package including a plurality of leads and a resin member fixing at least a part of the plurality of leads, a plurality of light-emitting elements, and a mold resin portion. The resin package is provided with one recessed portion defined by the resin member and the plurality of leads in a primary surface. Each of the plurality of leads includes an exposed region exposed at an inner upper surface of the one recessed portion. The plurality of light-emitting elements includes a first light-emitting element, a second light-emitting element, and a third light-emitting element that are disposed in the one recessed portion of the resin package. Each of the plurality of light-emitting elements is disposed in the exposed region of one of the plurality of leads. The mold resin portion includes a base portion sealing the plurality of light-emitting elements and a plurality of lens portions positioned above the base portion and integrally formed with the base portion. The plurality of lens portions include a first lens portion overlapping, in a plan view, the first light-emitting element, a second lens portion overlapping, in a plan view, the second light-emitting element, and a third lens portion overlapping, in a plan view, the third light-emitting element.
A method of manufacturing a light-emitting device according to one embodiment of the present disclosure includes preparing a first structure and forming a mold resin portion. The first structure includes a resin package including a plurality of leads and a resin, and a plurality of light-emitting elements mounted on a primary surface of the resin package. The resin member includes a first step surface oriented in a direction identical to the primary surface in a lateral surface portion of the resin package. The mold resin portion seals the plurality of light-emitting elements of the first structure. The forming includes injecting a resin material into a casting case, immersing the plurality of light-emitting elements of the first structure and a part of the resin package including the primary surface in the resin material to cause a part of the resin material to rise between the lateral surface portion of the resin package and an inner wall of the casting case toward the first step surface along the lateral surface portion of the resin package, and curing the resin material.
According to an embodiment of the present disclosure, a light-emitting device that can reduce deterioration of characteristics of the light-emitting device by using a waterproof resin can be provided.
Embodiments of the present disclosure will be described below with reference to the drawings as appropriate. Light-emitting devices to be described below are intended to embody technical idea of the present disclosure, and the present disclosure is not limited to the description below unless otherwise specified. Further, the content described in one embodiment can also be applied to another embodiment or modified example. Furthermore, sizes, positional relationships, or the like of members illustrated in each of the drawings may be exaggerated for clarity of description.
In the description below, components having substantially the same function may be denoted by the same reference numerals and repetitive description thereof may be omitted. Also, components that are not referenced in the description may not be designated with reference numerals. In the following description, terms indicating a specific direction or position (“upper”, “lower”, “right”, “left”, and other terms including those terms) may be used. These terms are used merely facilitate understanding relative directions or positions in the referenced drawing. As long as the relative direction or position is the same as that described in the referenced drawing using the term such as “upper” or “lower”, in drawings other than the drawings of the present disclosure, actual products, manufacturing devices, and the like, components is not necessarily arranged in the same manner as in the referenced drawing. In the present disclosure “parallel” includes, unless otherwise stated, in a case in which two straight lines, sides, faces, or the like are in a range from 0° to about 5°. Further, in the present disclosure, “perpendicular” or “orthogonal” includes, unless otherwise stated, in a case in which two straight lines, sides, faces, or the like are in a range of about ±5° from 90°.
When describing a direction with reference to an axis and a positive (+) direction or a negative (−) direction of the axis relative to a reference is important, description will be made by distinguishing + and − of the axis. Accordingly, a direction toward the + side of the x-axis will be referred to as a “+x direction” and a direction toward the − side of the x-axis will be referred to as a “−x direction”. Similarly, directions toward the + sides of the y-axis and the z-axis will be referred to as a “+y direction” and a “+z direction” and directions toward the − sides of the y-axis and the z-axis will be referred to as a “−y direction” and a “−z direction”. On the other hand, in a case in which the direction along a certain axis is important and whether the direction is the + direction or the − direction of the axis is inconsequential, the direction will simply be described as the “axis direction”. Further, a plane including the x-axis and the y-axis will be referred to as an “xy plane”, a plane including the x-axis and the z-axis will be referred to as an “xz plane”, and a plane including the y-axis and the z-axis will be referred to as a “yz plane”.
As illustrated in
The resin package 100 includes a plurality of leads 11a to 13b and a resin member. In the present embodiment, the resin member is, for example, a first dark-colored resin member 40 formed of a dark-colored resin. Here, “dark-colored resin” is a resin in which, in a plan view, at least a portion exposed at a primary surface 100a of the resin package 100 has a dark color. The resin package 100 includes the primary surface 100a, a back surface 100b positioned opposite to the primary surface 100a, and a lateral surface portion (hereinafter referred to as an “outer side portion”) 100c of the resin package 100 positioned between the primary surface 100a and the back surface 100b. Each of the plurality of leads 11a to 13b includes an exposed region 30 exposed from the first dark-colored resin member 40 at the primary surface 100a. The outer side portion may be covered by a mold resin portion or may be exposed to the outside without being covered.
Each of the first light-emitting element 51 to the third light-emitting element 53 is disposed in the exposed region 30 of one of the plurality of leads 11a to 13b.
The mold resin portion 60 includes a base portion 61 sealing the plurality of light-emitting elements 50 and a plurality of lens portions 70 positioned above the base portion 61.
The plurality of lens portions 70 are integrally formed with the base portion 61. In a plan view, the plurality of lens portions 70 include a first lens portion 71 overlapping the first light-emitting element 51, a second lens portion 72 overlapping the second light-emitting element 52, and a third lens portion 73 overlapping the third light-emitting element 53.
As illustrated in
As illustrated in
In the present embodiment, the lens portions 70 are provided on the emission side of the corresponding light-emitting elements 50. With this structure, the light-emitting device 1000 can extract light in a frontward direction (+z direction) with high efficiency, making it possible to obtain the light-emitting device 1000 having high brightness.
Further, in a cross-sectional view, the base portion 61 and the resin package 100 are disposed so that the first point P is positioned closer to the lens portions 70 than the second point Q, and thus, when the mold resin portion 60 is formed by a casting method, for example, the mold resin portion 60 is easily removed from a casting case. The second point Q is preferably positioned below (−z direction) the primary surface 100a of the resin package 100.
Furthermore, the base portion 61 and the resin package 100 are disposed so that the second point Q is positioned outward of the third point R in a cross-sectional view. Thus, in a display device such as an outdoor display that uses the light-emitting device 1000, when a waterproof resin is formed on a lateral surface of the light-emitting device 1000, it is possible to reduce a continuous rise of the waterproof resin in the +z direction along the lateral surface of the light-emitting device 1000 and subsequent adherence of the waterproof resin from the upper surface 61a to the lens portions 70. Accordingly, a decrease in brightness and a decrease in light distributivity due to a part of the waterproof resin being disposed on the lens portions 70 can be reduced.
As illustrated in
Note that “plan view” refers to a plan view as viewed in the +z-axis direction. “Top view” refers to a top view as viewed in the +z-axis direction. “Lateral side view” refers to a lateral side view as viewed in a direction orthogonal to any lateral surface of the external shape of the light-emitting device in a plan view.
Each of the components will be described in detail below.
Resin Package 100
In the present embodiment, the resin package 100 is a surface-mounted package.
As illustrated in
Note that the shape of the primary surface 100a in a top view may be a shape other than the quadrangular shape, and may be, for example, a substantially triangular shape, a substantially quadrangular shape, a substantially pentagonal shape, a substantially hexagonal shape, another polygonal shape, or a shape including a curved line such as a circular shape or an elliptical shape.
The resin package 100 includes the plurality of leads 11a to 13b and the first dark-colored resin member 40 that fixes at least a part of the plurality of leads 11a to 13b.
Step Surface of Resin Package 100
As illustrated in
In the example illustrated in
As illustrated in
By providing the first step surface st1, it is possible to control a shape of the mold resin portion 60. Accordingly, the light-emitting device 1000 can expose the back surface 100b of the resin package 100 from the mold resin portion 60. Thus, it is possible to reduce mounting defects of the light-emitting device 1000 at the time of mounting (when the back surface 100b of the resin package 100 is covered by the mold resin portion 60, the back surface 100b may not be wet by solder during mounting, for example) and enhance the reliability of the light-emitting device 1000.
A distance Hs from the back surface 100b of resin package 100 to the first step surface st1 of resin package 100 (hereinafter referred to as “height of the first step surface st1”) may be, for example, 0.2 mm or greater. Alternatively, a ratio Hs/Hq of the height Hs of the first step surface st1 to a height Hq of the second point Q may be, for example, 0.2 or greater. By setting the height Hs or the ratio Hs/Hq to within the range described above, it is possible to reduce the rise of the resin material that is to become the mold resin portion 60 to the leads in an immersion step described below when forming the mold resin portion 60 using a casting method. The height Hs of the first step surface st1 is more preferably 0.3 mm or greater, and even more preferably 0.35 mm. The ratio Hs/Hq is more preferably 0.4 or greater. The height Hs of the first step surface st1 is the shortest distance between the back surface 100b of the resin package 100 and the first step surface st1 along the z-axis direction. The height Hq of the second point Q is the shortest distance from the back surface 100b of the resin package 100 to the second point Q along the z-axis direction, in a cross-sectional view.
On the other hand, the height Hs of the first step surface st1 may be, for example, 1.5 mm or less. Alternatively, the ratio Hs/Hq of the height Hs of the first step surface st1 to the height Hq of the second point Q may be, for example, 0.8 or less. By setting the height Hs or the ratio Hs/Hq to within the range described above, it is possible to ensure a distance between a point where the resin material, which becomes the mold resin portion 60, begins to rise in the −z direction and the first step surface st1 in the immersion step described below when forming the mold resin portion 60. Therefore, a maximum amount of the resin material that can be disposed on the outer side portion 100c of the resin package 100 due to the rise in the immersion step (maximum volume of the resin material that can be caused to rise in the −z direction) can be increased, making it possible to fix the resin package 100 more stably. The height Hs of the first step surface st1 is more preferably 1.0 mm or less, and even more preferably 0.7 mm or less. The ratio Hs/Hq described above is more preferably 0.7 or less.
A width ws1 may be, for example, 0.1 mm or greater. More preferably, the width ws1 is in a range from 0.15 mm to 0.4 mm. With the width ws1 being 0.1 mm or greater, it is possible to reduce the rise of the resin material, which becomes the mold resin portion 60, when forming the mold resin portion 60. As illustrated in
In a cross-sectional view, a point positioned on an outermost of the first step surface st1 of the resin package 100 may be positioned inward of the second point Q of the mold resin portion 60. Thus, the lateral surface portion 61b of the mold resin portion 60 protrudes outward of the first step surface st1, making it possible to reduce a further upward rise (+z direction) by the waterproof resin (
As illustrated in
In the example illustrated in
By providing the second step surface st2, in a case in which a part of the resin material rising in the −z direction from the casting case does not stop at the first step surface st1, it is possible to stem the resin material that does not stop at the first step surface st1 by the second step surface st2. Accordingly, contact between the mold resin portion 60 and the plurality of leads 11a to 13b can be reduced. At least a portion of the outer side portion 100c of the resin package 100 positioned proximate to the back surface 100b relative to the second step surface st2 may be exposed from the mold resin portion 60. The lowermost end of the mold resin portion 60 may come into contact with the second step surface st2.
As illustrated in
First Recessed Portion 21
As illustrated in
As illustrated in
As illustrated in
In the example illustrated in
The primary surface 100a of the resin package 100 may further include at least one second recessed portion defined by the first dark-colored resin member 40 and the plurality of leads 11a to 13b. In this example, the primary surface 100a includes a plurality of (here, two) second recessed portions 22, 23.
Similar to the first recessed portion 21, the second recessed portions 22 and 23 also include inner upper surfaces 22a and 23a, and inner lateral surfaces 22c and 23c, respectively. In a plan view, the inner upper surface 22a of the second recessed portion 22 is surrounded by the upper surface of the second resin portion 42. Further, in a plan view, the inner upper surface 23a of the second recessed portion 23 is surrounded by the upper surface of the second resin portion 42. In the present embodiment, the first recessed portion 21, the second recessed portion 22, and the second recessed portion 23 are spaced apart from each other with the second resin portion 42 interposed therebetween, in a top view.
Each of the inner upper surfaces 22a, 23a of the second recessed portions 22, 23 includes, respectively, the exposed region of at least one lead. The exposed region of the lead includes a connection region wr to which a wire for electrically connecting the lead and the light-emitting element 50 is bonded.
In the example illustrated in
As illustrated in
As illustrated in
Note that an arrangement, a quantity, a planar shape, and the like of the recessed portions 21 to 23 are not limited to those in the example illustrated.
First Dark-Colored Resin Member 40
The first dark-colored resin member 40 has insulating properties for electrically isolating the light-emitting elements from the outside. Preferably, at least a portion of the first dark-colored resin member 40 positioned proximate to the primary surface 100a of the resin package 100, that is, proximate to a light emission observation surface, is a dark color such as black or gray. The first dark-colored resin member 40 may be colored to the dark color, for example. Alternatively, the first dark-colored resin member 40 may be obtained by printing dark-colored ink on a white-colored resin. Alternatively, the first dark-colored resin member 40 may be formed in two colors of a dark-colored resin and a white-colored resin. With this structure, in the primary surface 100a of the resin package 100, deterioration in contrast caused by reflection of external light and the like can be reduced. Note that, in this description, “dark color” refers to a color having a color value of 4.0 or less in the Munsell color system (20 hues). The hue is not particularly limited, and the chroma may be freely determined as necessary. Preferably, the color value is 4.0 or less and the chroma is 4.0 or less.
As described above, in the example illustrated in
In this example, the second resin portion 42 includes a resin portion 42A (also referred to as “surrounding resin portion”) that surrounds the inner upper surfaces 21a to 23a of the first recessed portion 21 and the second recessed portions 22 and 23, respectively, a resin portion 42B (also referred to as “outer resin portion”) positioned outward of the resin portion 42A, and a pair of resin portions 42C (also referred to as “dividing resin portions”) positioned between the first recessed portion 21 and second recessed portion 22, and the first recessed portion 21 and second recessed portion 23, respectively, in a top view. Note that the resin portion 42C may be singular, or there may be one or more pairs.
An upper surface of the resin portion 42A is positioned above (+z side) upper surfaces of the corresponding resin portions 42B and 42C. By making the upper surface of the resin portion 42A higher than the upper surfaces of the corresponding resin portions 42B and 42C, a light-transmissive resin member 180 is easily disposed in the region defined by the resin portion 42A, for example. Further, the upper surfaces of the corresponding resin portions 42C may be positioned above the upper surface of the resin portion 42B, for example. With this structure, a thickness of the light-transmissive resin member 180 can be ensured above the light-emitting elements 50 by utilizing the upper surfaces of the corresponding resin portions 42C. Further, by making the upper surface of the resin portion 42B lower than the resin portion 42A, a thickness of a portion of the base portion 61 positioned on the resin portion 42B can be increased. Note that, in this description, the “upper surface” of each resin portion is the surface positioned on the +z-most side. A portion of each resin portion positioned on the +z-most side may be a ridge line. In this case, a portion of each resin portion (ridge line or surface) positioned on the +z-most side has the positional relationship described above.
Each of the resin portions 42C is, for example, a wall-shaped portion having a rectangular planar shape extending in the y-axis direction. In a plan view, the resin portions 42C divide the first recessed portion 21 and the second recessed portion 22, and the first recessed portion 21 and the second recessed portion 23, respectively. In a plan view, each end portion of the resin portions 42C in the longitudinal direction may come into contact with the resin portion 42A. Further, here, the light-emitting elements 50 are disposed between the pair of resin portions 42C arrayed in the x-axis direction, facing each other.
In a plan view, a pair of resin portions 42D may be further disposed between the pair of resin portions 42C. Each resin portion 42D is positioned between the first resin portion 41 and the resin portion 42A on the inner upper surface 21a of the first recessed portion 21. Each of the resin portions 42D has a rectangular planar shape extending in the x-axis direction, for example. In the present embodiment, the resin portions 42C, 42D are connected and thus surround the inner upper surface 21a of the first recessed portion 21.
According to the configuration described above, as illustrated in
As illustrated in
As illustrated in
The first dark-colored resin member 40 has a shape with which the first dark-colored resin member 40 can hold at least a part of the plurality of leads 11a to 13b, and the shape is not limited to that illustrated in the drawings. Preferably, the first dark-colored resin member 40 integrally fixes a plurality of leads (here, three pairs of leads). With each lead firmly fixed by the first dark-colored resin member 40, vibration of the leads can be reduced when the mold resin portion 60 is formed by a transfer molding method.
As a material of the first dark-colored resin member 40, a material having a small coefficient of thermal expansion and an excellent adhesion performance with the mold resin portion 60 may be selected. The coefficient of thermal expansion of the first dark-colored resin member 40 may be substantially equal to the coefficient of thermal expansion of the mold resin portion 60 or, taking into account an influence of heat from the light-emitting elements 50, may be smaller than the coefficient of thermal expansion of the mold resin portion 60.
The first dark-colored resin member 40 can be formed by using a thermoplastic resin, for example. As the thermoplastic resin, a thermoplastic resin, such as an aromatic polyamide resin, a polyphthalamide resin (PPA), a sulfone resin, a polyamide-imide resin (PAI), a polyketone resin (PK), a polycarbonate resin, polyphenylene sulfide (PPS), a liquid crystal polymer (LCP), an ABS resin, and a PBT resin, can be used. Note that a thermoplastic resin containing glass fibers may also be used as a thermoplastic material. In this manner, by adding the glass fibers to the thermoplastic resin, it is possible to form a resin package having a high rigidity and a high strength. Note that, in this description, the “thermoplastic resin” refers to a material having a linear polymer structure that softens and then becomes liquid when heated and that solidifies when cooled. Examples of such a thermoplastic resin include styrene-based, acrylic-based, cellulose-based, polyethylene-based, vinyl-based, polyamide-based, and fluorocarbon-based resins.
Alternatively, the first dark-colored resin member 40 may be formed by using a thermosetting resin such as a silicone resin or an epoxy resin, for example.
A colorant that colors the first dark-colored resin member 40 to a dark color may be added to the resin material of the first dark-colored resin member 40. Various dyes and pigments are suitably used as the colorant. Specific examples include Cr2O3, MnO2, Fe2O3, and carbon black. An amount of the colorant to be added may be, for example, in a range from 0.3% to 3.0%, and preferably in a range from 1.0% to 2.0% with respect to the resin material that forms the base material. As an example, as the thermoplastic resin material, a thermoplastic resin material in which a small amount of dark-colored particles such as carbon particles is added to the polyphthalamide (PPA) may be used.
Leads
Each of the leads is conductive and functions as an electrode for supplying power to the corresponding light-emitting element 50.
As illustrated in
In a configuration exemplified in
In the example illustrated in
Each of the one leads 11a, 12a, and 13a of the first lead pair, the second lead pair, and the third lead pair, respectively, includes the exposed region 30a at the inner upper surface 21a of the first recessed portion 21. Each exposed region 30a includes an element placement region in which the corresponding light-emitting element 50 is disposed. Further, each of the leads 11a, 12a, and 13a includes the exposed region 30b, which is to become the connection region wr, at the inner upper surface 22a of the second recessed portion 22. The connection region wr is a region in which the corresponding light-emitting element is electrically connected to positive and negative electrodes by the wire. Each of the other leads 11b, 12b, and 13b of the first lead pair, the second lead pair, and the third lead pair, respectively, includes the exposed region 30, which is to become the connection region wr, at the inner upper surface 23a of the second recessed portion 23.
The leads 11a to 13b may be composed of a base material and a metal layer covering a surface of the base material. Examples of the base material include metals such as copper, aluminum, gold, silver, iron, nickel, alloys thereof, phosphor bronze, or ferrous copper. These base materials may have a single-layer structure or a layered structure (a clad material, for example). Copper may be used for the base material. The metal layer is, for example, the plating layer. Examples of the metal layer include silver, aluminum, nickel, palladium, rhodium, gold, copper, or alloys thereof. With the leads 11a to 13b including such a metal layer, light reflectivity and/or bonding properties with metal wires (described below) and the like of the leads 11a to 13b can be improved. For example, a lead including a silver-plated layer on a surface of a copper alloy that serves as the base material may be used.
An arrangement, a shape, a quantity, and the like of the leads used in the light-emitting device 1000 are not limited to the illustrated example. Although six leads are used in the illustrated example, in a case in which two or more light-emitting elements 50 among the first light-emitting element 51 to the third light-emitting element 53 are connected to a common lead, the number of leads may be less than six. For example, one common lead may be provided in place of the leads 11b to 13b described above.
Light-Emitting Element 50
The light-emitting element 50 is a semiconductor light-emitting element such as a semiconductor laser or a light-emitting diode. An emission wavelength of each of the light-emitting elements 50 can be selected as desired.
A shape of each light-emitting element 50 in a plan view is, for example, rectangular. A size of each light-emitting element 50 is not particularly limited. Vertical and horizontal lengths of each light-emitting element 50 are, for example, in a range from 100 μm to 1000 μm. For example, each light-emitting element 50 has a square shape with one side being 320 m in a plan view.
In the present embodiment, the plurality of light-emitting elements 50 include the first light-emitting element 51 that emits first light, the second light-emitting element 52 that emits second light having a wavelength shorter than that of the first light, and the third light-emitting element 53 that emits third light having a wavelength shorter than that of the second light. The emission wavelength of each of the light-emitting elements 50 may be selected so as to obtain white light or mixed-color light of a light bulb color when the plurality of light-emitting elements 50 are illuminated. For example, the first light-emitting element 51 may be a red light-emitting element that emits red light, the second light-emitting element 52 may be a green light-emitting element that emits green light, and the third light-emitting element 53 may be a blue light-emitting element that emits blue light. The combination of the number of light-emitting elements and the emitted light colors is merely an example and is not limited to this example. The three light-emitting elements 50 may emit light having the same wavelength.
As the blue and green light-emitting elements, light-emitting elements using ZnSe or a nitride-based semiconductor (InXAlYGa1-X-YN, 0≤X, 0≤Y, X+Y≤1) can be used. For example, a light-emitting element in which a semiconductor layer including GaN is formed on a support substrate such as sapphire may be used. As the red light-emitting element, a GaAs-based, AlInGaP-based, or AlGaAs-based semiconductor or the like can be used. For example, a light-emitting element in which a semiconductor layer including AlInGaP is formed on a support substrate such as silicon, aluminum nitride, or sapphire may be used. Furthermore, a semiconductor light-emitting element made from materials other than above can be used. The composition, emitted light color, size, number, and the like of the light-emitting element can be selected as appropriate in accordance with an intended purpose.
Further, by disposing phosphor, which performs wavelength conversion of light emitted from a semiconductor chip, around the semiconductor chip composed of a nitride-based semiconductor or the like, any desired light emission can be obtained. In this description, the “light-emitting element 50” includes not only the semiconductor chip composed of the nitride-based semiconductor or the like, but also an element composed of the semiconductor chip and the phosphor. Specific examples of the phosphor include yttrium-aluminum-garnet activated by cerium, lutetium-aluminum-garnet activated by cerium, nitrogen containing calcium aluminosilicate activated by europium and/or chromium (part of the calcium can be substituted with strontium), sialon activated by europium, silicate activated by europium, strontium aluminate activated by europium, and potassium fluorosilicate activated by manganese. As an example, the first light-emitting element 51, the second light-emitting element 52, and the third light-emitting element 53 may each include a semiconductor chip that emits blue light. In this case, by disposing the phosphor around the semiconductor chip in each of at least two of those light-emitting elements, the emitted light colors of the first light-emitting element 51, the second light-emitting element 52, and the third light-emitting element 53 can be caused to be different from each other.
Each of the first light-emitting element 51, the second light-emitting element 52, and the third light-emitting element 53 can be bonded, using a bonding member such as a resin, solder, or a conductive paste, to the exposed region 30 of any of the plurality of leads 11a to 13b.
The first light-emitting element 51 to the third light-emitting element 53 may be disposed in the exposed regions 30a of three different leads (here, leads 11a, 12a, and 13a). With this structure, heat dissipation paths of the first light-emitting element 51, the second light-emitting element 52, and the third light-emitting element 53 can be separated from each other, and thus heat generated by each of the light-emitting elements 50 can be efficiently dissipated.
As illustrated in
As the wires 81 to 83, metal wires made of gold, silver, copper, platinum, aluminum, or alloys thereof can be used. Among these, it is preferable to use a gold wire having excellent ductility, or a gold-silver alloy wire having a higher reflectivity than that of the gold wire.
In the configuration illustrated in
Reflective Member 150
In the present embodiment, the reflective member 150 may surround each of the light-emitting elements 50 in a plan view. The reflective member 150 reflects light emitted from a lateral surface of each of the light-emitting elements 50 and guides the light to above the light-emitting elements 50. With this structure, the use efficiency of the light emitted from the light-emitting elements 50 can be improved.
In this description, “the reflective member 150 surrounding the light-emitting element 50” includes a case in which the reflective member 150 is positioned close to the lateral surface of the light-emitting element 50 in a plan view. The reflective member 150 may be in direct contact or may not be in contact with the lateral surface of the light-emitting element 50. Preferably, the reflective member 150 is in contact with the lateral surface of the light-emitting element 50. More preferably, the reflective member 150 surrounds the lateral surface of the light-emitting element 50 in a plan view. The reflective member 150 is preferably provided in contact with all lateral surfaces of the light-emitting element 50. This makes it possible to more effectively reduce leakage, in the x directions and the ±y directions, of the light emitted from the light-emitting element 50.
Note that the reflective member 150 is disposed in close proximity to the lateral surface of the light-emitting element 50 and may not be disposed over the entire inner upper surface 21a of the first recessed portion 21. For example, each of the light-emitting elements 50 whose lateral surface covered with the reflective member 150 may be prepared, and the light-emitting elements 50 may then be disposed on the inner upper surface 21a (refer to
As illustrated in
With the first reflective member 151 to the third reflective member 153 disposed, it is possible to reflect light from the lateral surface of each of the light-emitting elements 50 toward the light-emitting element 50 and emit the light beams from upper surfaces of the light-emitting elements 50 in the frontward direction (+z direction) of the light-emitting device 1000. Accordingly, it is possible to reduce the size of light source surface (creating a point light source) from which light from each of the first light-emitting element 51 to the third light-emitting element 53 is emitted, in a top view. Creating the point light source refers to light being emitted from the lateral surface of the light-emitting element 50 at 10% or less. Thus, by making the light-emitting elements 50 into point light sources, it is possible to reduce sizes of the planar shapes of the corresponding lens portions 70. Accordingly, by reducing the size of the lens portion 70, it is possible to reduce a size of the light-emitting device 1000. With an emission direction of the light from each of the light-emitting elements 50 being controlled within a desired range, it is possible to reduce light loss caused by total reflection on inner surfaces of the corresponding lens portions 70. The inner surface of the lens portion 70 is a surface on which the light emitted from the light-emitting element 50 hits from an inner side. The inner surface of the lens portion 70 may be referred to as an outer surface of the light-emitting device 1000. Accordingly, light extraction of the light-emitting device 1000 can be maintained, and light can be extracted with high efficiency in the frontward direction. The mold resin portion 60 includes an inner surface and an outer surface. The outer surface of the mold resin portion 60 is a surface of an exposed side (outer side) of the light-emitting device 1000. The inner surface of the mold resin portion 60 is a surface facing the light-emitting elements 50 (inner side). The inner surface of the lens portion 70 is the surface of an inner side of the lens portion 70.
In the present embodiment, the first reflective member 151 to the third reflective member 153 are positioned in the one first recessed portion 21 of the resin package 100. With this structure, the inner lateral surface 21c of the first recessed portion 21 can be utilized to control the positions of the first reflective member 151 to the third reflective member 153, and thus the reflective member 150 can surround the first light-emitting element 51 to the third light-emitting element 53. The reflective member 150 is preferably not formed in a region other than the first recessed portion 21 of the primary surface 100a.
As illustrated in
The first reflective member 151 to the third reflective member 153 can also be respectively disposed between the exposed regions 30a of the leads and lower surfaces of the first light-emitting element 51 to the third light-emitting element 53. For example, a reflective member (a resin including a light reflective material, for example) may be applied in advance in the first recessed portion 21, and the first light-emitting element 51 to the third light-emitting element 53 may then be disposed thereon. This makes it possible to more effectively reduce leakage, in the −z direction, of the light emitted from each of the first light-emitting element 51 to the third light-emitting element 53. Further, a die bond resin is not required to bond the first light-emitting element 51 to the third light-emitting element 53 to the primary surface 100a.
For example, the reflective member 150 is a reflective resin. The reflective resin includes a resin serving as a base material and a light reflective material dispersed in the resin. As the base material, a light-transmissive material such as an epoxy resin, a silicone resin, an epoxy-modified silicone resin, a resin obtained by mixing them, glass, or the like can be used. From the perspective of light resistance and ease of formation, a silicone resin is preferably selected as the base material.
As the light reflective material, titanium oxide, silicon oxide, zirconium oxide, yttrium oxide, yttria-stabilized zirconia, potassium titanate, aluminum oxide, aluminum nitride, boron nitride, mullite, and the like can be used. In the present embodiment, for example, titanium oxide is used. A concentration of the light reflective material in the reflective member 150 is preferably in a range from 10 wt. % to 80 wt. %. The reflective member 150 preferably includes titanium oxide as the light reflective material. Further, the reflective member 150 may include a glass filler or the like in order to reduce expansion and contraction caused by heat of the resin of the base material. A concentration of the glass filler is preferably greater than 0 wt. % and less than 40 wt. %. Note that the concentrations of the light reflective material, the glass filler, and the like are not limited thereto.
The reflective member 150 is a member that reflects the light emitted from the light-emitting element 50. The reflective member 150 is preferably formed of a material having a reflectance of 80% or greater with respect to the light emitted from the light-emitting element 50. Note that the reflective member 150 may be a member that blocks the light emitted from the light-emitting element 50. For example, as the reflective member 150, a single layer film or multilayer film made of a metal, or a multilayer film (dielectric multilayer film) formed by layering a plurality of dielectrics of two or more types can be used. As the dielectric multilayer film, a distributed Bragg reflector (DBR) film, for example, may be used.
Light-Transmissive Resin Member 180
As illustrated in
In the illustrated example, the light-transmissive resin member 180 is disposed in a region surrounded by the resin portion 42A, which has the highest height within the second resin portion 42 in the +z direction. With this structure, the upper surface of the resin portion 42A can be utilized to form the light-transmissive resin member 180 having a constant thickness in the entire region surrounded by the resin portion 42A. The light-transmissive resin member 180 may cover the light-emitting elements 50, the reflective member 150, and the resin portions 42C. The light-transmissive resin member 180 preferably has a thickness in a range from 40 μm to 180 μm from the upper surfaces of the light-emitting elements 50. More preferably, the thickness is in a range from 50 μm to 140 μm. Even more preferably, the thickness is in a range from 60 μm to 100 μm.
The light-transmissive resin member 180 can cover the reflective member 150 and the light-emitting elements 50, for example. For example, the light-transmissive resin member 180 may be disposed in a region surrounded by the resin portions 42C and the resin portions 42D. In this case, the light-transmissive resin member 180 may be disposed by utilizing the stepped portions positioned between the first lateral surfaces s1 and the upper surfaces u1 of the pair of resin portions 42C in a cross-sectional view. For example, the light-transmissive resin member 180 may cover the above stepped portions and not cover the upper surfaces u1. An interface between the light-transmissive resin member 180 and the mold resin portion 60 can be a surface (incident surface) on which light beams emitted from the light-emitting elements 50 is incident. As the light-transmissive resin member 180, a resin (silicone resin, epoxy resin, or epoxy-modified silicone resin, for example) having excellent thermal resistance and weather resistance can be used.
Mold Resin Portion 60
The mold resin portion 60 includes the base portion 61 and the plurality of lens portions 70. The base portion 61 and the lens portions 70 are integrally formed.
Base Portion 61
As illustrated in
In the present embodiment, the base portion 61 includes, for example, the upper surface 61a positioned above the primary surface 100a of the resin package 100. The upper surface 61a may be one size larger than the primary surface 100a of the resin package 100.
In a lateral side view, the base portion 61 includes the lateral surface portion 61b extending from the upper surface 61a of the base portion 61 in a back surface direction of the resin package 100. The lateral surface portion 61b covers at least a part of the outer side portion 100c of the resin package 100.
The lateral surface portion 61b preferably covers only a part of the outer side portion 100c of the resin package 100. That is, a part of the outer side portion 100c of the resin package 100 is preferably exposed from the lateral surface portion 61b of the base portion 61. As illustrated, the outer side portion 100c of the resin package 100 may be exposed from the lateral surface portion 61b of the base portion 61 at a part closer to the back surface 100b than the first step surface st1, for example.
A lowermost end of the base portion 61 positioned furthest in the −z direction is preferably positioned above portions of the outer side portion 100c where the leads 11a to 13b are exposed and is preferably designed so that the mold resin portion 60 and the leads 11a to 13b do not come into direct contact with each other. With this structure, a part of the mold resin portion 60 does not partially cover the mounting surfaces of the leads 11a to 13b. Therefore, a decrease in the areas of the mounting surfaces by the mold resin portion 60 can be reduced.
In the present embodiment, in a cross-sectional view, the first light-emitting element 51 is preferably positioned closer to the back surface 100b (−z side) of the resin package 100 than the first point P and is preferably positioned above the second point Q (+z side). In the z-axis direction, the first light-emitting element 51 may be positioned between the first point P and the second point Q. With this structure, a distance between the first light-emitting element 51 and the first lens portion 71 in the z-axis direction can be reduced. Similarly, in a cross-sectional view, each of the second light-emitting element 52 and the third light-emitting element 53 may be positioned closer to the back surface 100b of the resin package 100 than the first point P and may be positioned above the second point Q.
In the cross-sectional views illustrated in
Further, by disposing the first light-emitting element 51 to the third light-emitting element 53 above the second point Q, it is possible to sufficiently separate the first light-emitting element 51 to the third light-emitting element 53 from the interface portion 1000u between the mold resin portion 60 and the resin package 100.
In a cross-sectional view, the second point Q is preferably positioned closer to the back surface 100b of the resin package 100 than the inner upper surface 21a of the first recessed portion 21. In the z-axis direction, the second point Q may be positioned between the inner upper surface 21a of the first recessed portion 21 and the back surface 100b of the resin package 100. This makes it possible to sufficiently separate the first light-emitting element 51 to the third light-emitting element 53 from the interface portion 1000u between the mold resin portion 60 and the resin package 100.
In a cross-sectional view, a portion of the lateral surface portion 61b of the base portion 61 from the second point Q to the third point R is preferably curved in a recessed shape. In the example illustrated in
By increasing the length of the first portion S in a cross-sectional view, it is possible to further improve a waterproof performance. The reason is as follows. When moisture penetrates from an uppermost end of a contact portion between the lateral surface of the light-emitting device 1000 and the waterproof resin, the penetrated moisture flows downward (−z direction) between first portion S of the outer lateral surface of the mold resin portion 60 and the waterproof resin. When a part of this moisture reaches the interface portion 1000u between the mold resin portion 60 and the resin package 100 (
In the present embodiment, a height Hr of the third point R is preferably less than ½ of the height Ha of the primary surface 100a of the resin package 100. The height Hr of the third point R is the shortest distance between the third point R and the back surface 100b in the z-axis direction. With this structure, the interface portion 1000u that is to be the moisture penetration area can be disposed lower (−z side) in the light-emitting device 1000, making it possible to further improve the waterproof performance of the light-emitting device 1000.
With reference to
The distance Hx between the second point Q and the third point R in the x-axis direction is not particularly limited, but may be, for example, 0.05 mm or greater, preferably 0.1 mm or greater. This makes it possible to more effectively reduce the rise of the waterproof resin to above the first portion S. Further, by lengthening the distance Hx, it is possible to increase the length of the first portion S in a cross-sectional view. On the other hand, from the viewpoint of miniaturization of the light-emitting device 1000, the distance Hx may be, for example, 0.5 mm or less, preferably 0.3 mm or less.
With such a configuration, the rise of the waterproof resin disposed on the lateral surface of the light-emitting device 1000 can be more effectively reduced. As described below, the lateral surface portion 61b having the cross-sectional shape described above can be easily formed by utilizing the rise of the resin material when forming the mold resin portion.
In a cross-sectional view, the second point Q of the mold resin portion 60 is preferably positioned above (+z side) the first step surface st1 of the resin package 100 and is preferably positioned below (−z side) the primary surface 100a. This makes it possible to reduce the contact of the lowermost end of the mold resin portion 60 with the leads 11a to 13b. With this structure, when the light-emitting device 1000 is mounted, it is possible to ensure the mounting surfaces of the leads 11a to 13b with respect to the mounting substrate.
As illustrated in
As illustrated in
If the ratio Wq/W1 is 0.1 or greater, a distance between the resin package 100 positioned in the casting case and an inner wall of the casting case can be sufficiently ensured when the mold resin portion 60 is formed by a casting method. Accordingly, voids in the resin material injected into the casting case can readily escape to the outside through a gap between the casting case and the side portion of the resin package 100.
If the gap between the resin package 100 and the inner wall of the casting case is too small, a maximum amount of resin material that can rise to the outer side portion 100c of the resin package 100 when the resin package 100 is immersed in the casting case, that is, the maximum amount of the resin material that rises from the gap but does not reach the leads, is reduced. Accordingly, it may no longer be possible to dispose enough resin material on the outer side portions 100c of the resin package 100, or the amount of the resin material may be greater than a predetermined range, making it difficult to reduce the rise of the resin material at the first step surface st1. Note that, even in such a case, for example, as long as the width of the first step surface st1 is increased, the base portion 61 having a desired shape can be formed. In contrast, if the size of W1 is fixed and Wq/W1 is 0.1 or greater, the gap between the resin package 100 and the inner wall of the casting case increases. Therefore, a range of the rise amount of the resin material that can achieve the desired shape also increases. Accordingly, the base portion 61 having a desired shape can be formed. Further, the amount of the resin material is easily adjusted, making it possible to increase a degree of freedom of design of the first step surface st1 that can control the shape of the mold resin portion 60. The width Wq is preferably designed to be, for example, 0.4 mm or greater. On the other hand, when the size of W1 is fixed and Wq/W1 is 0.5 or less, the size of the light-emitting device 1000 can be suppressed to a smaller size.
Lens Portion 70
The lens portion 70 has a light distribution function of controlling a direction and a distribution of the light to be emitted.
In the present embodiment, each of the plurality of lens portions 70 has a convex shape protruding upwardly from the upper surface 61a of the base portion 61. The planar shape of each lens portion 70 is, for example, elliptical or circular. In the illustrated example, the planar shape of each lens portion 70 is elliptical, with a major axis of the elliptical shape extending in the x-axis direction and a minor axis of the elliptical shape extending in the y-axis direction. Thus, a light distribution that is wide in the x-axis direction and narrow in the y-axis direction can be obtained. The light-emitting device 1000 having such a light distribution can be particularly suitably used in a display device such as an LED display. Note that, in a lateral side view as viewed in the x-axis direction or the y-axis direction, an outer edge of the lens portion 70 may have a linear portion in addition to a curved portion such as an elliptical arc shape or an arc shape. The linear portion may be positioned between the curved portion and the upper surface 61a of the base portion 61. For example, the lens portion 70 may have a shape in which a part of a sphere (hemisphere, for example) is disposed on a circular truncated cone, or a shape in which a part of an ellipsoid is disposed on an elliptical truncated cone.
Each of the plurality of lens portions 70 is disposed correspondingly to one of the light-emitting elements 50 in a one-to-one relationship. An optical axis of each lens portion 70 may coincide with a center of the corresponding light-emitting element 50 (center of the light-emitting surface). With this structure, controllability of the light distribution of the light-emitting device 1000 can be further improved.
Note that the shape and arrangement of each of the lens portions 70 in a plan view can be selected as appropriate taking into account light distribution performance, light collection performance, and the like. Further, the cross-sectional shape of the lens portion is not limited to a convex shape. The lens portion may be, for example, concave or a Fresnel lens.
In the present embodiment, the first light emitted from the first light-emitting element 51 is transmitted through the first lens portion 71 and exits from an emission surface of the light-emitting device 1000. The direction of emission and the distribution of the first light are controlled by the first lens portion 71. Similarly, the second light emitted from the second light-emitting element 52 is transmitted through the second lens portion 72, and the third light emitted from the third light-emitting element 53 is transmitted through the third lens portion 73. The second lens portion 72 and the third lens portion 73 control the light distribution of the second light and the third light, respectively.
When the first light-emitting element 51, the second light-emitting element 52, and the third light-emitting element 53 are illuminated, mixed light of the light beams transmitted through the first lens portion 71, the second lens portion 72, and the third lens portion 73 is, for example, white.
In the example illustrated in
Material of Mold Resin Portion 60
The mold resin portion 60 includes a base material having light transmissivity. The mold resin portion 60 preferably has a light transmittance of 90% or greater at respective peak wavelengths of the plurality of light-emitting elements 50. With this structure, the light extraction efficiency of the light-emitting device 1000 can be further improved.
As the base material of the mold resin portion 60, a thermosetting resin such as an epoxy resin, a urea resin, a silicone resin, or a modified silicone resin such as an epoxy-modified silicone resin, glass, or the like having excellent weather resistance and light transmissivity is suitably used.
The mold resin portion 60 according to the present embodiment can also contain a light-diffusing material in order to improve a uniformity of the quality of the light of the light-emitting device 1000. With the mold resin portion 60 containing the light-diffusing material, the light emitted from the light-emitting element 50 can be diffused to suppress unevenness in light intensity. As such a light-diffusing material, an inorganic material such as barium oxide, barium titanate, silicon oxide, titanium oxide, and aluminum oxide, or an organic material such as a melamine resin, a CTU guanamine resin, and a benzoguanamine resin is suitably used.
The mold resin portion 60 may contain various fillers. Although a specific material of the filler is similar to the light-diffusing material, the central particle size (D50) differs from that of the light-diffusing material. In this description, “filler” refers to a filler having a central particle size in a range from 100 nm to 100 μm. When the filler having such a particle size is contained in a light-transmissive resin, chromaticity variation of the light-emitting device 1000 can be improved by a light-scattering effect, and further heat shock resistance of the light-transmissive resin can be enhanced and internal stress of the resin can be alleviated.
A surface roughness of the base portion 61 is not particularly limited, but from the perspective of improving the display contrast, the surface roughness is preferably large. A part or all of the surface of the base portion 61 may be roughened, for example. Of the upper surface 61a of the base portion 61, at least the portion that does not overlap the plurality of lens portions 70 in a plan view is preferably roughened. An outer surface of the lateral surface portion 61b of the base portion 61 may also be roughened. A surface roughness of the upper surface 61a and a surface roughness of the outer surface of the lateral surface portion 61b may be the same or may be different. From the perspective of ease of processing, the surface roughness of the upper surface 61a and the surface roughness of the outer surface of the lateral surface portion 61b are preferably the same. With the surface roughness of the base portion 61 being large, external light such as sunlight can be scattered on the surface of the base portion 61, and thus the reflection intensity can be reduced. With this structure, deterioration in contrast due to external light reflection can be reduced.
The surface roughness of the portion, of the upper surface 61a of the base portion 61, that does not overlap the plurality of lens portions 70 in a plan view may be greater than the surface roughness of the lens portion 70, for example. Such a structure is obtained by, for example, forming the mold resin portion 60 including the base portion 61 and the lens portions 70, and subsequently performing roughening processing such as blasting on a predetermined region of the surface of the base portion 61. Alternatively, a casting case (refer to
An arithmetic mean roughness Ra of the upper surface 61a of the base portion 61 is preferably in a range from 0.4 μm to 5 μm. More preferably, Ra is in a range from 0.8 μm to 3 μm. Ra of an outer surface of the lateral surface portion 61b of the base portion 61 may also be in the same range as described above. Ra can be measured in accordance with the method for measuring the surface roughness stipulated in JIS B 0601-2001. Specifically, Ra is expressed by the following equation, when a portion of a measurement length L is extracted from a roughness curve in the direction of the center line thereof, the center line of the extracted portion is the x-axis, a direction of the longitudinal magnification is the y-axis, and the roughness curve is y=f(x).
A contact type surface roughness measuring machine, a laser microscope, or the like can be used for measuring Ra. In this description, the laser microscope VK-250 available from Keyence is used.
The base portion 61 preferably has a light transmittance of 90% or greater at respective peak wavelengths of the plurality of light-emitting elements 50. With this structure, the light extraction efficiency of the light-emitting device 1000 can be further improved.
Display Device 2000
The light-emitting device of the present embodiment can be applied to a display device such as an outdoor display, for example. An example of a display device that uses the light-emitting device according to the present embodiment will be described below.
The display device 2000 includes a substrate 1 such as a printed circuit board, a plurality of light-emitting devices 2 arrayed in two dimensions on the substrate 1, and a waterproof resin 3. The light-emitting device 2 illustrated in
The waterproof resin 3 covers a surface of the substrate 1 and a part of a lateral surface of the light-emitting device 2. The waterproof resin 3 prevents moisture from penetrating into an interior of the light-emitting device 2 and protects terminal portions and light-emitting elements.
In the illustrated configuration, moisture from outside the display device 2000 readily penetrates the interior of the light-emitting device 2 from the interface portion (including the third point R) 1000u between the resin package 100 and the mold resin portion 60, for example. Therefore, preferably the waterproof resin 3 provides coverage from a lowermost portion of the lateral surface of the light-emitting device 2 to a portion positioned above the interface portion, which is to become the moisture penetration area, between the resin package 100 and the mold resin portion 60. On the other hand, an uppermost end of the waterproof resin 3 is preferably positioned below the upper surface 61a of the base portion 61. This is because, when the waterproof resin 3 is disposed on the upper surface 61a of the base portion 61 and on the lens portion 70, the extraction efficiency of light from the light-emitting device 2 may deteriorate, and light distribution controllability by the lens portion 70 may deteriorate.
The waterproof resin (silicone resin, for example) 3 is typically applied after the plurality of light-emitting devices 2 are mounted on the substrate 1. In the present embodiment, in a cross-sectional view of the light-emitting device 2, the third point R that is the moisture penetration area is positioned closer to the lens portion 70 than the second point Q that is the outermost point of the lateral surface portion 61b of the base portion 61, and thus the waterproof resin 3 readily covers the lateral surface of the light-emitting device 2 from the lowermost portion to at least the third point R. Accordingly, the penetration of moisture from the interface portion 1000u between the mold resin portion 60 and the resin package 100 can be more effectively reduced. Further, the lateral surface of the light-emitting device 2 (outer surface of the base portion 61) extends to the second point Q like an eave, and thus the waterproof resin 3 is unlikely to rise along the lateral surface of the light-emitting device 2 beyond the second point Q. Accordingly, arrangement of a part of the waterproof resin 3 on the upper surface 61a of the base portion 61 and the lens portions 70 can be reduced. For example, in a cross-sectional view, the uppermost end of the waterproof resin 3 may be positioned above the interface portion 1000u and below the second point Q. In other words, of the lateral surface of the base portion 61, a portion positioned above the second point Q may be exposed from the waterproof resin 3.
Note that, although the display device 2000 for an outdoor display is described here as an example, application of the display device 2000 is not particularly limited. Further, in a case in which the lateral surface of the light-emitting device 2 is covered with a resin for purposes other than waterproofing, the arrangement of the resin can be controlled by the shape of the lateral surface of the light-emitting device 2, and thus the same effects as those described above can be achieved.
Method of Manufacturing Light-Emitting Device 1000
An example of a method of manufacturing the light-emitting device 1000 will be described below.
First Step: Preparation of Resin Package 100
In a first step, the resin package 100 is prepared that includes the first dark-colored resin member 40 and the plurality of leads, as illustrated in
First, a lead frame including a plurality of leads is prepared. In this example, the lead frame includes three pairs of leads per package. Each of the lead pairs includes the leads 10a and 10b that are spaced apart from each other.
Subsequently, a mold is prepared, and the lead frame is placed in the mold. After this, a thermoplastic resin material colored to a dark color is injected into the mold and solidified by being cooled. Thus, the resin package 100 that holds the plurality of leads 10a and 10b is obtained by means of the first dark-colored resin member 40.
A structure of the resin package 100 is similar to the structure described above with reference to
Second Step: Mounting of Light-Emitting Elements 50
In a second step, as illustrated in
Third Step: Formation of Reflective Member 150 and Light-Transmissive Resin Member 180
In a third step, as illustrated in
The reflective member 150 is obtained by first applying the first resin material serving as the reflective member to inside the first recessed portion 21 of the resin package 100 using a nozzle, and then curing the first resin material.
Further, the second dark-colored resin member 190 may be formed by applying a dark-colored resin material to inside the second recessed portions 22 and 23 and then curing the resin material. Note that the first resin material and the resin material that serve as the second dark-colored resin member may be simultaneously applied using a plurality of nozzles and simultaneously cured. Because the work can be performed simultaneously, the steps can be simplified. Further, the second dark-colored resin may be applied and cured, and then the first resin material may be applied.
Subsequently, the light-transmissive resin member 180 is obtained by applying a second resin material, which is to become the light-transmissive resin member, so as to cover the light-emitting elements 50, the reflective member 150, and the resin portions 42C in the region defined by the resin portion 42A of the second resin portion 42.
Note that the resin materials that are to become the reflective member and the second dark-colored resin member may be heated at a temperature below a curing temperature to provisionally cure the resin materials, and the second resin material that is to become the light-transmissive resin member may be disposed on the provisionally cured bodies that are to become the reflective member and the second dark-colored resin member. Subsequently, the provisionally cured bodies that are to become the reflective member and the second dark-colored resin member and the second resin material may be heated at a temperature equal to or higher than the curing temperature and fully cured. Alternatively, the mold resin portion may be formed in a state in which the resin materials of the reflective member, the second dark-colored resin member, and the light-transmissive resin member are provisionally cured. In this case, these resin materials may be fully cured in a curing step for forming the mold resin portion. Thus, a first structure 110 is obtained in which the light-emitting elements 50, the reflective member 150, and the light-transmissive resin member 180 are disposed on the primary surface 100a of the resin package 100.
Fourth Step: Formation of Mold Resin Portion 60
In a fourth step, the mold resin portion 60 is formed by using, for example, a casting method. The base portion 61 of the mold resin portions 60 and the lens portions 70 are, for example, integrally formed. The base portion of the mold resin portion 60 and the lens portions 70 may be separated.
Preparation of Casting Case 120
First, as illustrated in
The upper cavity 121 has a shape corresponding to a part of the base portion. For example, the bottom surface 121b of the upper cavity 121 has a shape corresponding to the upper surface 61a (
The lower cavity 130 has a shape corresponding to the lens portion. Here, the plurality of lower cavities 130 are three lower cavities including a first cavity for the first lens portion, a second cavity for the second lens portion, and a third cavity for the third lens portion.
Third Resin Material Injection Step
Subsequently, as illustrated in
Here, an epoxy resin is used as the base material of the third resin material 142. The third resin material 142 is injected into the lower cavities 130 and the upper cavity 121. An injection volume of the third resin material 142 into the upper cavity 121 is preferably set to be smaller than a total volume of the upper cavity 121 and the lower cavities 130. This makes it possible to suppress the rise of the third resin material 142 in the subsequent immersion step to an amount controllable by the first step surface st1. As illustrated, the third resin material 142 may include an upper surface having a recessed shape that comes into contact with a peripheral edge of the opening 120p. On the other hand, when the injection volume of the third resin material 142 is too small, the third resin material 142 cannot be caused to rise in the subsequent immersion step. Therefore, the injection volume of the third resin material 142 is set to be greater than an amount obtained by subtracting a volume of a portion of the resin package 100 to be immersed from an internal volume of the upper cavity 121. Note that the third resin material 142 may be injected into the lower cavities 130 and provisionally cured, and subsequently the third resin material 142 may be injected into the upper cavity 121.
Immersion Step
Subsequently, as illustrated in
A predetermined space (clearance) d is formed between the outer side portion 100c of the resin package 100 and the inner wall 121c of the upper cavity 121 of the casting case 120. The space d corresponds to the width Wq illustrated in
The first structure 110 is immersed, causing a part of the third resin material 142 to rise from between the outer side portion 100c of the resin package 100 and the inner wall 121c of the upper cavity 121 of the casting case 120 along the outer side portion 100c of the resin package 100 toward the first step surface st1 as illustrated by an arrow 800 in
The rise of the third resin material 142 is reduced by the first step surface st1 provided on the outer side portion 100c of the resin package 100. As illustrated in
Note that the shape of the third resin material 142 is not limited to the shape illustrated in
Curing Step
With the first structure 110 immersed in the third resin material 142, the third resin material 142 is cured. A curing step is performed at a temperature equal to or greater than a curing temperature of the base material of the third resin material 142. After curing, the casting case 120 is removed. Thus, as illustrated in
Note that, although the third resin material 142 is injected continuously into the lower cavities 130 and the upper cavity 121 here, the third resin material 142 may be injected into the lower cavities 130 and then provisionally cured, subsequently the third resin material 142 may be injected into the upper cavity 121, and then the provisionally cured lower cavities 130 and the third resin material 142 injected into the upper cavity 121 may be fully cured.
The first point P of the mold resin portion 60 may be a point corresponding to a corner portion of the bottom surface 121b and the inner wall 121c of the upper cavity 121. The second point Q may be a point corresponding to an upper end of the opening 120p of the upper cavity 121. The third point R may be a point corresponding to the upper end 142e of the risen portion of the third resin material 142.
In the examples illustrated in
Subsequently, the leads 11a to 13b are cut from the lead frame and separated, and thus the light-emitting device 1000 is obtained.
According to the method of manufacturing of the present embodiment, in the immersion step of the first structure, the mold resin portion 60 having a desired shape can be formed by utilizing the rise of the resin material. Thus, it is possible to reduce an increase in manufacturing costs and in the number of manufacturing steps.
Various modified examples can be conceived with respect to the light-emitting device. For example, the structure and arrangement of the light-emitting elements, the structure and form of the resin package, the configuration of the mold resin portion, and the like are not limited to those modes described in the above-described embodiment. Modes other than those described in the above-described embodiment can be suitably used in the light-emitting device of the present disclosure.
Modified examples of the light-emitting device of the present disclosure will be described below. In the following, points different from those of the light-emitting device 1000 will be mainly described, and a description of structures similar to those of the light-emitting device 1000 will be omitted. Further, in each of the drawings illustrating the modified examples, components similar to those of the light-emitting device 1000 are denoted by the same reference signs for ease of understanding.
The light-emitting device 1001 differs from the light-emitting device 1000 illustrated in
In the present modified example, in a cross-sectional view, the outer lateral surface of the lateral surface portion 61b of the base portion 61 includes a step surface (hereinafter referred to as “base step surface”) 62 oriented in the same direction as the primary surface 100a, between the first point P and the second point Q. The outer lateral surface of the lateral surface portion 61b of the base portion 61 has a stepped shape in a cross-sectional view, and the base step surface 62 is a surface corresponding to a tread of a step. In this example, the base step surface 62 is positioned below the primary surface 100a of the resin package 100. Further, in a top view, the base step surface 62 is formed around an outer periphery of the base portion 61.
As illustrated in
The resin package 100 in the present modified example may further include a tapered surface 100t inclined relative to the primary surface 100a of the resin package 100, between the primary surface 100a and the outer side portion 100c. The tapered surface 100t is positioned above the second point Q of the base portion 61. In a lateral side view, the base step surface 62 may overlap the tapered surface 100t.
The tapered surface 100t is a surface inclined at an angle θt in a range from 35° to 45°, for example, relative to the primary surface 100a (here, the xy plane), in the −z direction. The inclination angle θt of the tapered surface 100t relative to the xy plane is smaller than an inclination angle θc of a portion of the outer side portion 100c that comes into contact with the tapered surface 100t.
As illustrated in
Structures of the first resin portion 41 and the resin portions 42A, 42C, and 42D, which are the second resin portion, in the present modified example are not particularly limited, but may be similar to or may be different from those of the light-emitting device 1000 described above, for example. As illustrated in
According to the present modified example, by forming the base step surface 62 on the base portion 61, it is possible to form a mold resin portion having reduced voids using a casting method. The method will be described below with reference to the drawings.
In the present modified example, the amount of the third resin material 142 can be set to be less than the volume of the upper cavity 121, and the step surface 123 can be utilized for control so as to ensure that the upper surface of the third resin material 142 is convex.
A distance c1 (corresponding to the distance h1 of the base portion) from the bottom surface 121b of the upper cavity 121 to the step surface 123 in the z-axis direction may be greater than a distance c2 (corresponding to the distance h2 of the base portion) from the upper end of the inner wall 121c of the upper cavity 121 to the step surface 123 in the z-axis direction. This makes it possible to accommodate a desired amount of the third resin material 142 in the upper cavity 121 and make the upper surface thereof convex in shape while suppressing a size (volume) of the upper cavity 121.
In this step, because the third resin material 142 includes an upper surface having a convex shape, it is possible to reduce the occurrence of voids v generated in the third resin material 142 in association with the immersion of the first structure 110 including the resin package 100. More specifically, because the upper surface of the third resin material 142 has a convex shape, a central portion of the resin package 100 comes into contact with the third resin material 142 before a peripheral edge portion.
Further, in the present modified example, because the resin package 100 includes the tapered surface 100t, a volume of a portion positioned in the upper cavity 121 between the outer side portion 100c of the resin package 100 and the inner wall 121c of the upper cavity 121 can be increased. As the resin package 100 is immersed deeper, the voids v generated in the third resin material 142 move from the central portion of the upper cavity 121 (a portion positioned between the central portion of the immersed resin package 100 and the bottom surface 121b of the upper cavity 121) toward the inner wall 121c, along an arrow 801 illustrated in
If the upper cavity 121 includes the step surface 123, the path of the voids v is more likely to narrow below (+z side) the step surface 123. In this case, by making the space d between the upper end of the inner wall 121c of the upper cavity 121 and the outer side portion 100c of the resin package 100 larger, it is possible to ensure a pathway of the voids v. Further, by providing the tapered surface 100t in the resin package 100, it is possible to ensure an escape path for the voids v without increasing the volume of the upper cavity 121 (that is, increasing a size of the base portion).
A width of the step surface 123 in a direction parallel to the primary surface 100a (corresponding to the width w1 of the step surface of the mold resin portion) may be set to be smaller than the space d between the upper end of the inner wall 121c of the upper cavity 121 and the outer side portion 100c of the resin package 100. Thus, the path of the voids v can be ensured between the inner wall 121c and the outer side portion 100c of the resin package 100.
Note that the effect of the tapered surface 100t is not dependent on the shape of the upper cavity. For example, even in a case in which the upper cavity does not include a step surface, the effect of facilitating the removal of voids can be achieved by providing the resin package with the tapered surface 100t.
The light-emitting device 1002 differs from the light-emitting device 1001 according to the first modified example in that, in the primary surface 100a of the resin package 100, an upper surface of a resin portion 42F positioned between the first recessed portion 21 and the second recessed portions 22 and 23 is higher than an upper surface of a resin portion 42E positioned outward of the resin portion 42F.
In the present modified example, in the primary surface 100a, the first dark-colored resin member 40 includes the first resin portion 41 positioned on the inner upper surface 21a of the first recessed portion 21 and the second resin portion 42 that surrounds the inner upper surface 21a of the first recessed portion 21 in a plan view and includes an upper surface positioned above an upper surface of the first resin portion 41. In a plan view of the primary surface 100a of the resin package 100, the second resin portion 42 includes the resin portion 42E (also referred to as “third resin portion”) and the resin portion 42F (also referred to as “fourth resin portion”) positioned between the resin portion 42E and the first resin portion 41. The upper surface of the resin portion 42F is positioned above the upper surface of the resin portion 42E, and the upper surface of the resin portion 42E is positioned above the upper surface of the first resin portion 41. In a top view, the tapered surface 100t may be formed outward of the resin portion 42E.
According to the configuration described above, as illustrated in
In the example illustrated in
The resin portion 42F includes, for example, a pair of wall-shaped portions having a rectangular planar shape extending in the y-axis direction and a pair of wall-shaped portions having a rectangular planar shape extending in the x-axis direction, and these wall-shaped portions define each side of the inner upper surface 21a having a quadrangular shape in a plan view. The inner upper surfaces 22a and 23a of the second recessed portions 22 and 23, respectively, are surrounded by the resin portion 42F and the resin portion 42E. For example, the resin portion 42E includes a pair of wall-shaped portions positioned on the −x side and the +x side of the resin portion 42E in a plan view. One of the pair of wall-shaped portions of the resin portion 42E extends so as to define three of the four sides of the inner upper surface 22a having a quadrangular shape in a plan view, excluding one side positioned proximate to the resin portion 42F. The other of the pair of wall-shaped portions of the resin portion 42E extends so as to define three of the four sides of the inner upper surface 23a having a quadrangular shape in a plan view, excluding one side positioned proximate to the resin portion 42F. That is, in a plan view, one of the four sides of each of the inner upper surfaces 22a and 23a is defined by the resin portion 42F, and the other three sides are defined by the resin portion 42E. A cross-sectional shape of the resin portion 42F is not particularly limited, but as illustrated in
The light-emitting devices 1003 and 1003a of the present modified example differ, in the resin package 100, from the light-emitting device 1000 illustrated in
In the light-emitting device 1003 illustrated in
In the present modified example as well, the reflective member may be disposed in the first recessed portion 21. The reflective member is disposed at least in each of the element placement regions 201 to 203. The reflective member may also be disposed in the intervening regions 211 and 212.
The light-emitting device 1003a illustrated in
The light-emitting devices 1004, 1004a, and 1004b of the present modified example differ from the light-emitting devices 1000 to 1003 described above in that the first recessed portion 21 is not provided in the primary surface 100a of the resin package 100. That is, in the present modified example, the region in which the light-emitting elements are disposed is not surrounded by a resin portion including an upper surface higher than the first resin portion 41. In the manufacture of the light-emitting devices 1004, 1004a, and 1004b, the first light-emitting element 51 to the third light-emitting element 53 each covered by the reflective member on the lateral surface in advance are preferably disposed on the primary surface 100a of the resin package 100 (refer to
In the light-emitting device 1004 illustrated in
The protruding portions 45a and 45b are spaced apart from each other. In this example, the protruding portion 45b is disposed on the +x side of the protruding portion 45a and spaced apart from the protruding portion 45a. The protruding portions 45a and 45b include the corresponding side walls facing each other with the element placement regions 201 to 203 and the intervening regions 211 and 212 interposed therebetween. These sidewalls define a part of a peripheral edge of the first region 300. The other parts of the peripheral edge of the first region 300 (here, the portions positioned on the −y side and the +y side) may be defined by a peripheral edge of the primary surface 100a of the resin package 100.
Each of the first light-emitting element 51 to the third light-emitting element 53 is disposed in the exposed region 30 of one of the plurality of leads 11a to 13b in the first region 300. The first region 300 may include the connection region wr.
In the light-emitting device 1004 illustrated in
Shapes of the protruding portions 45a, 45b in a plan view, a shape of the first region 300 defined by the protruding portions 45a, 45b in a plan view, and the like in the present modified example are not limited to the example illustrated in
The light-emitting device 1004a may include, instead of the protruding portion 45a, a plurality of protruding portions spaced apart from each other. Similarly, the light-emitting device 1004a may include, instead of the protruding portion 45b, a plurality of protruding portions spaced apart from each other. Each of the plurality of protruding portions may include a lateral surface positioned on the corresponding one lead and defining a peripheral edge of the corresponding element placement regions 201 to 203. In a plan view, a width of each protruding portion in the y-axis direction may be larger than a width of the corresponding lead.
The light-emitting device 1004b illustrated in
The light-emitting device 1005 differs from the light-emitting devices 1000 to 1003 described above in that the lens portions 70 are colored to the same type of color as emitted light colors of the corresponding light-emitting elements.
By disposing the lens portion 70, colored to the same type of color as the emitted light color of the light-emitting element 50, above (+z direction) the light-emitting element 50, it is possible to reduce deterioration in the display contrast caused by external light reflection on the reflective member surrounding the light-emitting element 50 and on the exposed surface of the lead while the light-emitting elements 50 are turned off, without interfering the emitted light color when the light-emitting element 50 is turned on.
Furthermore, in a case in which the first light-emitting element 51, the second light-emitting element 52, and the third light-emitting element 53 are all turned off, due to the subtractive color mixing of the first lens portion 71, the second lens portion 72, and the third lens portion 73, the first lens portion 71, the second lens portion 72, and the third lens portion 73 each appear darker than the color with which it is colored, that is, appear as a color of a lower color value than that of the color with which it is colored. Accordingly, the emission surface of the light-emitting device 1005 appears darker, so that the display contrast can be further increased.
The mold resin portion 60 of the light-emitting device 1005 can be manufactured by, for example, a casting method.
As illustrated in
The light-emitting device 3000 according to the sixth modified example differs from the light-emitting device 1000 illustrated in
In the present modified example, the first light-emitting element 51, the second light-emitting element 52, and the third light-emitting element 53 each have a rectangular planar shape. In a plan view, each side of the rectangular shape of at least one light-emitting element (here, the third light-emitting element 53) of the first light-emitting element 51, the second light-emitting element 52, and the third light-emitting element 53 is non-parallel to each side of the rectangular shapes of the other light-emitting elements (here, the first light-emitting element 51 and the second light-emitting element 52).
This makes it possible to improve the light distribution controllability of the light-emitting device 3000 and achieve the desired light distribution, as described in detail below.
Structure and Arrangement of Light-Emitting Elements
The first light-emitting element 51 to the third light-emitting element 53 each include a first surface positioned proximate to the plurality of leads 11a to 13b, a second surface positioned opposite to the first surface (that is, proximate to the lens portion), and two electrodes positioned on the second surface. Note that, in each of the first light-emitting element 51 to the third light-emitting element 53, both the positive and negative electrodes will be described as being positioned on the second surface, but one may be positioned on the first surface and the other may be positioned on the second surface.
In the example illustrated in
In the example illustrated in
In this description, the smallest angle α of the angles formed by each side of the outer edges of the rectangular shape of the light-emitting element and the line m0 in a plan view is referred to as an “inclination angle relative to the line m0”. In the illustrated example, the inclination angle α of each of the first light-emitting element 51 and the second light-emitting element 52 relative to the line m0 is 45°.
In a light-emitting device having a light-emitting element and a lens positioned above the light-emitting element and covering the light-emitting element, as the size of the lens decreases, the light distribution of the light-emitting device is more susceptible to being affected by light distribution characteristics of a near field of the light-emitting element. With this structure, light distribution control of the light-emitting device by adjusting the curvature of the lens may be difficult. The light distribution characteristics of the near field of the light-emitting element can be changed by, for example, the structure, such as the positions of the electrodes in the light-emitting element or the electrode size.
In contrast, in the present modified example, it is possible to achieve the light-emitting device 3000 having a desired light distribution (directional properties) by disposing the first light-emitting element 51 to the third light-emitting element 53 in the resin package 100 taking into consideration the positions of the electrodes of the first light-emitting element 51 to the third light-emitting element 53 and, more specifically, taking into consideration the light emission luminance distribution reflecting the positions and the like of electrodes on the second surface of these light-emitting elements.
Below, a relationship between the light emission luminance distribution of the light-emitting elements and the arrangement of the light-emitting elements in a plan view will be specifically described.
As illustrated in
The second light-emitting element 52 includes the electrodes at positions similar to those of the first light-emitting element 51. Accordingly, in the light emission luminance distribution of the second light-emitting element 52 as well, similarly to the first light-emitting element 51, a width of the light-emitting portion on a diagonal line connecting two corner portions of the second surface where the electrodes are not formed can be greater than a width of the light-emitting portion on a diagonal line connecting two corner portions where the electrodes are formed.
As illustrated in
In the present modified example, the first light-emitting element 51 to the third light-emitting element 53 are preferably disposed on the line m0 connecting the center points C1 to C3 of the first lens portion 71 to the third lens portion 73, respectively, in a plan view. In a plan view, a center of the second surface of each of the first light-emitting element 51 to the third light-emitting element 53 may be disposed on the line m0.
In the reference example illustrated in
When a light-emitting device arranged as in the present reference example is applied to a display device, display characteristics such as image color, video, and the like may be affected by the light distribution difference of the first and second light-emitting elements 51 and 52. For example, because the light distribution on the line m1 in the first light-emitting element 51 (red light-emitting element, for example) is narrow (half-value angle is small), when a display device that uses the light-emitting device is viewed from the direction of the line m1, image distortion such as a weak red color may occur.
In contrast, in the light-emitting device 3000 according to the present modified example, as illustrated in
In the present modified example, each of the first light-emitting element 51 to the third light-emitting element 53 is disposed so as to achieve a reduction in the difference between the width of the light-emitting portion 611 on the line m1 and the width of the light-emitting portion 611 on the line m2. For example, each of the first light-emitting element 51 to the third light-emitting element 53 may be disposed so that the electrodes do not overlap the line m1 and the line m2 in a plan view (that is, so that the electrodes are offset from the lines m1, m2). Alternatively, each of the first light-emitting element 51 to the third light-emitting element 53 may be disposed so that the shape of the light-emitting portion 611 in a plan view is substantially symmetric (line-symmetric) relative to the line m0 and/or the line m3.
By using the light-emitting device 3000 of the present modified example, it is possible to achieve a display device in which distortion of image color and video caused by a light distribution difference is further reduced.
As illustrated in
A shape of each of the first light-emitting element 51 to the third light-emitting element 53 in a plan view may be square. In this case, by disposing the first light-emitting element 51 to the third light-emitting element 53 as exemplified in
Note that the inclination angle α of each of the first light-emitting element 51 to the third light-emitting element 53 relative to the line m0 in a plan view can be set in accordance with the positions of the electrodes and the like in the light-emitting element, regardless of a wavelength of the light emitted from the light-emitting element. The inclination angle α of each of the first light-emitting element 51 to the third light-emitting element 53 relative to the line m0 can be selected in a range from 0° to 45° according to the planar shape of the light-emitting element, the position of the electrode, the electrode shape, and the like. In a case in which the planar shape of the light-emitting element is rectangular and includes the electrodes in two corner portions facing each other, the inclination angle α of the light-emitting element relative to the line m0 may be greater than 0° and less than 45°.
Size and Shape of Lens Portion
In the present modified example, the height of the vertex of at least one lens portion of the first lens portion 71, the second lens portion 72, and the third lens portion 73 differs from the heights of the vertices of the other lens portions.
In the example illustrated in
Further, in a plan view, sizes of the first lens portion 71 to the third lens portion 73 (widths WS1 to WS3 in the minor axis direction, widths WL1 to WL3 in the major axis direction) may be different from each other. Here, the width WS3 of the third lens portion 73 in the minor axis direction is larger than the widths WS1 and WS2 of the first lens portion 71 and the second lens portion 72, respectively, in the minor axis direction, and the width WL3 of the third lens portion 73 in the major axis direction is larger than the widths WL1 and WL2 of the first lens portion 71 and the second lens portion 72, respectively, in the major axis direction. The sizes of the first lens portion 71 and the second lens portion 72 in a plan view may be the same or may be different from each other.
In the example illustrated in
As described above, in a lateral side view as viewed in the x-axis direction and/or the y-axis direction, the outer edge of each of the first lens portion 71 to the third lens portion 73 may include a linear portion in addition to a curved portion. As an example, in a lateral side view as viewed in the y-axis direction, each of the lens portions 71 to 73 may include a linear portion, and in a lateral side view as viewed in the x-axis direction, each of the lens portions 71 to 73 may not include a linear portion. Further, shapes of the outer edges of the first lens portion 71 to the third lens portion 73, in a lateral side view, may be different from each other. For example, in a lateral side view as viewed in the y-axis direction, the outer edge of at least one lens portion of the first lens portion 71 to the third lens portion 73 may include a linear portion, and the outer edges of the other lens portions may not include linear portions.
A curvature of at least one lens portion of the first lens portion 71 to the third lens portion 73 may be different from the curvatures of the other lens portions. The curvatures of the first lens portion 71 to the third lens portion 73 may be different from each other. Alternatively, the first lens portion 71 to the third lens portion 73 may have the same curvature. In this description, “the curvature of the lens portion” refers to the curvature of a curved portion that, in a cross section along the major axis direction or the minor axis direction of the lens portion including the vertex of the lens portion, includes the vertex of the outer edge of the lens portion.
According to the present modified example, the light distribution controllability of the light that passes through each the lens portions 71 to 73 and is emitted from each of the first light-emitting element 51 to the third light-emitting element 53 can be enhanced by adjusting the size (for example, the heights HL1 to HL3 of the vertices T1 to T3, the widths WS1 to WS3 in the minor axis direction, and the widths WL1 to WL3 in the major axis direction), the curvature, and the like of the corresponding lens portion 70 in accordance with the respective light emission luminance distributions of the first light-emitting element 51 to the third light-emitting element 53. Further, the light distribution controllability and the light extraction efficiency of the light-emitting device 3000 can be improved by combining a configuration, described above, that makes the direction in which the width of the light-emitting portion in the light emission luminance distribution of each of the first light-emitting element 51 to the third light-emitting element 53 becomes relatively small match the minor axis of the corresponding lens portion and makes the direction in which the width of the light-emitting portion in the light emission luminance distribution of each of the first light-emitting element 51 to the third light-emitting element 53 becomes relatively large match the major axis of the corresponding lens portion, and a configuration that makes the size of the corresponding lens portion 70 increase in accordance with the light emission luminance distribution of each of the first light-emitting element 51 to the third light-emitting element 53.
For example, when the distribution of light emitted from a certain light-emitting element through the lens portion is to be narrowed, first the curvature of the lens portion is adjusted. When the light distribution is not sufficiently narrowed by the adjustment of the curvature alone, the size of the lens portion may be made larger than those of the other lens portions. Alternatively, the size of the lens portion may be made larger without changing the curvature of the lens portion.
In a case in which the light distribution of a certain light-emitting element (here, third light-emitting element 53) is wider than the light distribution of the other light-emitting elements, the distribution of the light (here, green light) emitted through the third lens portion 73 can be narrowed by making the size of the third lens portion 73 corresponding to the third light-emitting element 53 (for example, the height HL3 of the vertex of the lens portion 73) higher than those of the other lens portions 71 and 72. For example, as illustrated in
Note that, in the present modified example, the size of the third lens portion 73 is larger than those of the first lens portion 71 and the second lens portion 72, but a size relationship between the first lens portion 71 to the third lens portion 73 is not particularly limited. The sizes of these lens portions 71 to 73 can be set in accordance with the light emission luminance distribution caused by the electrode positions and the like of each of the light-emitting elements.
Of the first lens portion 71 to the third lens portion 73, the lens portion having the highest vertex (hereinafter referred to as the “highest lens portion”) is preferably disposed at one end of a row in which the first lens portion 71 to the third lens portion 73 are arrayed in one direction (hereinafter, “lens row”), in a plan view. In the example illustrated in
When the light-emitting device according to the present modified example is used in a display device such as an outdoor display, for example, three lens portions 70a to 70c of the light-emitting device may be disposed in a vertical direction of a display surface (surface from which light is emitted) of the display device. When such a display surface is viewed from below and the highest lens portion 70a is positioned in a center of the lens row as exemplified in
When the heights of the vertices of the three lens portions 70a to 70c are different from each other, the highest lens portion 70a is preferably disposed at the upper end of the lens row and the lowest lens portion 70c is preferably disposed at the lower end of the lens row as illustrated in
The light-emitting device 3001 and the light-emitting device 3000 illustrated in
In the example illustrated in
Note that, in the present modified example, the arrangement (inclination angle α relative to the line m0) of at least one light-emitting element of the first light-emitting element 51 to the third light-emitting element 53 is made to differ from those of the other light-emitting elements in accordance with the light emission luminance distribution of the first light-emitting element 51 to the third light-emitting element 53, and the sizes of the first lens portion 71 to the third lens portion 73 may be the same. Alternatively, the sizes of at least one lens portion of the first lens portion 71 to the third lens portion 73 is made to differ from those of the other lens portions in accordance with the light emission luminance distribution of the first light-emitting element 51 to the third light-emitting element 53, and the inclination angles α relative to the line m0 of the first light-emitting element 51 to the third light-emitting element 53 may be the same.
The light-emitting device 4000 of the seventh modified example differs from the light-emitting device 3000 illustrated in
In the example illustrated in
At least apart of a lateral surface of each protruding portion 46 is in contact with the reflective member 150. The upper surface 46u of the protruding portion 46 may be exposed from the reflective member 150. With the upper surface 46u of each protruding portion 46 being exposed from the reflective member 150 disposed in the first recessed portion 21, the reflective member 150 includes a plurality of holes corresponding to the protruding portions 46 in a plan view. With this structure, deterioration in the display contrast due to external light reflection by the reflective member 150 can be reduced. Note that the upper surface 46u of each protruding portion 46 may be covered by the light-transmissive resin member 180. The reflective member 150 disposed in the first recessed portion 21 may include a plurality of holes corresponding to the protruding portions 46 in a plan view.
According to the present modified example, in a plan view, the reflective member 150 can be disposed in a region of the inner upper surface 21a of the first recessed portion 21 excluding regions in which the protruding portions 46 are formed. With this structure, the volume of the reflective member 150 can be reduced. Thus, it is possible to reduce a stress on the light-emitting elements 50 that occurs during the manufacturing step and reduce the lifting of the light-emitting elements 50 from the leads 11. Further, with the first resin portion including the protruding portions, holes or grooves corresponding to the protruding portions 46 can be formed in the reflective member 150, and the reflective member 150 can be arranged in two or more regions spaced apart from each other with the protruding portions 46 interposed therebetween. Therefore, during the manufacture or mounting of the light-emitting device 4000, defects caused by the stress that occurs between the reflective member 150 and the light-emitting elements 50 can be reduced.
In the example illustrated in
A distance k1 between the upper surface 46u of the protruding portion 46 and the exposed region 30 in the z-axis direction is, for example, 0.1 mm. When the upper surface 46u of the protruding portion 46 is non-parallel to the xy plane, the distance k1 is a distance from the exposed region 30 to a portion of the upper surface 46u of the protruding portion 46 positioned on the +z-most side in the z-axis direction. A distance between the upper surface of the light-emitting element 50 and the exposed region 30 in the z-axis direction is greater than the distance k1 and is, for example, in a range from 0.12 mm to 0.2 mm.
In a plan view of the primary surface 100a of the resin package 100, at least one protruding portion 46 is positioned between two adjacent leads of the plurality of leads and includes a portion that overlaps at least one of the two adjacent leads. For example, the protruding portion 46 overlaps a part of the exposed region 30 in a plan view. This makes it possible to fix the lead frame by the protruding portion 46 so that the lead frame does not lift from the first dark-colored resin member 40 during the manufacture of the resin package 100.
In the example illustrated in
Note that the number of protruding portions 46 is not limited to the illustrated example. The light-emitting device 4000 according to the present modified example includes at least one protruding portion 46 in the first recessed portion 21 and may include five or more protruding portions 46.
Hereinafter, other light-emitting devices 4001 to 4005 of the seventh modified example will be described. In the following, points different from those of the light-emitting device 4000 will be mainly described, and description of structures and effects similar to those of the light-emitting device 4000 will be omitted.
In the example illustrated in
In the example illustrated in
According to the present modified example, in a plan view, the second dark-colored resin member 190 can be disposed in regions of the inner upper surfaces 22a and 23a of the second recessed portions 22 and 23, respectively, excluding regions in which the protruding portions 47 are formed. With this structure, the volume of the second dark-colored resin member 190 can be reduced. Further, holes or grooves can be formed in the second dark-colored resin member 190, and the second dark-colored resin member 190 can be arranged in two or more regions spaced apart from each other with the protruding portions 47 interposed therebetween. Therefore, effects caused by the stress that occurs during the manufacture or mounting of the light-emitting device 4001 can be reduced. For example, the stress on a bonding portion between a wire and a lead caused by a volume change in the second dark-colored resin member 190 can be reduced.
Preferably, each protruding portion 47 partially overlaps the corresponding lead in a plan view. This makes it possible to fix the lead frame by the protruding portion 47 so that the lead frame does not lift from the first dark-colored resin member 40 during manufacture of the resin package 100.
In the example illustrated in
In the light-emitting device 4002, the protruding portions 48 are provided, making it possible to divide the second dark-colored resin member 190 into six third recessed portions 24 spaced apart from each other. Therefore, effects caused by the stress that occurs during the manufacture or mounting of the light-emitting device 4002 can be reduced. Further, the protruding portions 48 connect the resin portions 42A and 42C in a plan view, making it possible to reduce warping of the resin package 100 during the manufacture or mounting of the light-emitting device 4002.
In the example illustrated in
A structure of the resin package 100 of the light-emitting device 4003 is a structure in which the protruding portion 49 is provided in the resin package 100 of the light-emitting device 1003a illustrated in
In the example illustrated in
The reflective member 150 is disposed in each of the element placement regions 201 to 203. The reflective member 150 disposed in each of the element placement regions 201 to 203 may be spaced apart from each other by the protruding portions 49. This makes it possible to reduce the effects of the stress that occurs during manufacture or during mounting. For example, the stress applied to the light-emitting elements 50 due to expansion and/or contraction of the reflective member 150 can be further reduced. Thus, peeling between the light-emitting elements 50 and the leads 11a, 12a, and 13a can be reduced. Note that the reflective member 150 disposed in each of the element placement regions 201 to 203 may be formed continuously in the first recessed portion 21.
In the example illustrated in
In the example illustrated in
In the example illustrated in
In the example illustrated in
In the example illustrated in
An example of a method of arranging the reflective member 150 will be described below using the element placement region 202 as an example with reference to
A surface area of the second resin portion 42 is increased by an amount equivalent to that of the constricted portions Pn, making it possible to increase a contact area with the mold resin portion. By the presence of the constricted portions Pn, an adhesive force between the mold resin portion and the resin package 100 can be increased, making it possible to fix the mold resin portion more stably to the resin package 100.
In the example illustrated in
The mold resin portion may include a portion positioned in an interior of the depression 49h of each protruding portion 49. The interior of the depression 49h may be in contact with the light-transmissive resin member 180. The light-transmissive resin member 180 may be disposed in a part of the interior of the depression 49h, and the mold resin portion may be disposed in another part of the interior of the depression 49h. An inner surface of the depression 49h may be in contact with the mold resin portion. For example, when the mold resin portion is formed, a resin material that is to become the mold resin portion may be applied so as to fill the depression 49h of each protruding portion 49, and then cured. This makes it possible to increase the adhesive force between the mold resin portion and the resin package 100 (anchor effect). Accordingly, the mold resin portion can be more stably fixed to the resin package 100. In the example illustrated in
According to the light-emitting device 4005, the width of each of the element placement regions 201 to 203 in the y-axis direction can be made larger than that of the light-emitting device 4004. Accordingly, for example, arranging the light-emitting elements 50, which are covered at lateral surfaces by the reflective member 150 in advance, in each of the element placement regions 201 to 203 is relatively easy.
In the example illustrated in
The light-emitting device according to the present disclosure can be suitably used as a light-emitting device in various applications. In particular, the light-emitting device according to the present disclosure is suitably used in a display device such as an LED display. The LED display is utilized for billboards, large televisions, advertisements, traffic signs, stereoscopic display devices, and lighting devices, for example.
Number | Date | Country | Kind |
---|---|---|---|
2021-162285 | Sep 2021 | JP | national |
2022-024239 | Feb 2022 | JP | national |
2022-083491 | May 2022 | JP | national |