JP6332294B2 - Light emitting device - Google Patents

Description

  The present disclosure relates to a light emitting device.

  A light emitting device using a semiconductor light emitting element is actively used not only for illumination but also as a vehicle headlight as the light output increases.

  For example, Patent Document 1 proposes a light-emitting device including a light-transmitting member connected to a light-emitting element and a light-reflective resin that covers at least a part of the light-transmitting member. In this light emitting device, the outer peripheral side surface of the translucent member has an inclined surface that extends from the upper surface direction toward the lower surface direction so as to contact the lower surface, and the area of the lower surface of the translucent member is equal to the area of the light emitting element. It is formed larger than the area of the upper surface. Further, in the light emitting device, the lower surface of the light transmissive member and the upper surface of the light emitting element are bonded, the lower surface of the light transmissive member, the portion not bonded to the light emitting element, and the inclined surface However, it has the structure coat | covered with the said light-reflective resin.

Japanese Patent No. 5482378

However, a light source that emits light with higher luminance is required for a light-emitting device for vehicle use or the like.
An object of the embodiment of the present disclosure is to provide a light-emitting device with higher luminance.

  A light-emitting device according to an embodiment of the present disclosure includes one or more light-emitting elements having an upper surface as a light extraction surface, and is bonded to the upper surface of the light-emitting element, and includes an upper surface and a lower surface. A translucent member that emits emitted light from the lower surface and emits the light from the upper surface to the outside; an upper surface of the translucent member is exposed; and a surface of the translucent member and a side surface of the light emitting element A light-reflective member that covers the light-transmitting member, wherein the light-transmitting member has an upper surface area that is smaller than a sum of the upper surface areas of the one or more light-emitting elements, and the light-transmitting member has a lower surface area, The structure is larger than the sum of the upper surface areas of one or more of the light emitting elements.

  The light emitting device according to the embodiment of the present disclosure can be a light emitting device with higher luminance.

1 is a perspective view schematically showing a cross section of a part of a light emitting device according to a first embodiment. It is a top view which shows typically the light-emitting device which concerns on 1st Embodiment. It is a perspective view which shows typically the translucent member of the light-emitting device which concerns on 1st Embodiment in a partial cross section. It is sectional drawing which shows typically the cross section of the light-emitting device in the AA of FIG. It is a top view which shows typically the board | substrate of the light-emitting device which concerns on 1st Embodiment. It is a bottom view which shows typically the board | substrate of the light-emitting device which concerns on 1st Embodiment. It is explanatory drawing which shows typically the state of the light with which the light-emitting device which concerns on 1st Embodiment is irradiated. It is explanatory drawing which shows typically the state of a board | substrate in the manufacturing method of the light-emitting device which concerns on 1st Embodiment. It is explanatory drawing which shows typically the state which mounted the light emitting element in the board | substrate in the manufacturing method of the light-emitting device which concerns on 1st Embodiment. It is explanatory drawing which shows typically the state which apply | coated the adhesive material on the light emitting element in the manufacturing method of the light-emitting device which concerns on 1st Embodiment. It is explanatory drawing which shows typically the state which joined the translucent member via the adhesive material on the light emitting element in the manufacturing method of the light-emitting device which concerns on 1st Embodiment. It is explanatory drawing which shows typically the state which provided the light reflective member as an underfill in the periphery of the light emitting element in the manufacturing method of the light-emitting device which concerns on 1st Embodiment. It is explanatory drawing which shows typically the state which provided the light reflection member in the surface except the upper surface of a light emitting element and a translucent member in the manufacturing method of the light-emitting device which concerns on 1st Embodiment. It is sectional drawing which shows the translucent member used for the light-emitting device which concerns on 2nd Embodiment. It is sectional drawing which shows the translucent member used for the light-emitting device which concerns on 3rd Embodiment. It is sectional drawing which shows the translucent member used for the light-emitting device which concerns on 4th Embodiment. It is a top view which shows typically the light-emitting device which concerns on 5th Embodiment. FIG. 11 is a cross-sectional view schematically showing a cross-section of the light-emitting device according to the fifth embodiment, taken along line AA in FIG. 10. It is sectional drawing which shows typically the cross section of the light-emitting device which concerns on 6th Embodiment. It is sectional drawing which cut | disconnects the cross section of the light-emitting device which concerns on 7th Embodiment in the center of the transversal direction of a light reflective member, and is shown typically. It is sectional drawing which cut | disconnects the cross section of the light-emitting device which concerns on 8th Embodiment typically at the center of the transversal direction of a light reflective member. It is a graph which shows the relationship between the area ratio of the upper surface and lower surface of a translucent member, and a luminance ratio.

  Hereinafter, the light emitting device according to each embodiment will be described with reference to the drawings. The drawings referred to in the following description schematically show the respective embodiments, and therefore the scale, spacing, positional relationship, etc. of each member are exaggerated, or some of the members are not shown. There may be. Moreover, in the following description, the same name and code | symbol indicate the same or the same member in principle, and shall omit detailed description suitably. Furthermore, the directions shown in each figure indicate relative positions between components, and are not intended to indicate absolute positions.

<First Embodiment>
An example of the configuration of the light emitting device according to the first embodiment will be described with reference to FIGS.
As shown in FIGS. 1 and 2, the light emitting device 1 includes at least one light emitting element 10 and a light transmissive member that emits light from the light emitting element 10 from the lower surface 7 and emits the light from the upper surface 3 to the outside. 2 and a light reflective member 20 that exposes the upper surface 3 of the light transmissive member 2 and covers the surface of the light transmissive member 2 and the side surface of the light emitting element 10. Is further provided.

(Light emitting element)
As the light emitting element 10, a known one can be used. For example, it is preferable to use a light emitting diode. Moreover, the light emitting element 10 can select the thing of arbitrary wavelengths. For example, as blue and green light-emitting elements, those using ZnSe, nitride-based semiconductors (In _X Al _Y Ga _1-XY N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1), or GaP are used. it can. Furthermore, GaAlAs, AlInGaP, or the like can be used as a red light emitting element. The light emitting element 10 may be a semiconductor light emitting element made of a material other than those described above. The composition, emission color, size, number, and the like of the light emitting element 10 can be appropriately selected according to the purpose. The light emitting element 10 preferably has a pair of positive and negative electrodes on the same surface side. Thereby, the light emitting element 10 can be flip-chip mounted on the substrate. In this case, the surface facing the surface on which the pair of electrodes is formed is the main light extraction surface 11 of the light emitting element. When the light emitting element 10 is mounted face up on the substrate, the surface on which the pair of electrodes are formed becomes the main light extraction surface 11 of the light emitting element 10.

In the present embodiment, the light emitting element 10 has a pair of electrodes flip-chip mounted on the conductor wiring (positive electrode 32, negative electrode 33, intermediate electrode 34) of the substrate 30 via a connecting member. The light emitting element 10 has a surface on which an electrode is formed as a lower surface and an upper surface opposite to the lower surface as a light extraction surface 11.
The light emitting device 1 according to the present embodiment includes a plurality of light emitting elements 10, and the plurality of light emitting elements 10 are arranged in a rectangular shape as a whole in plan view.

(Translucent member)
As shown in FIGS. 1 to 4, the translucent member 2 is formed in a convex shape from the lower surface 7 toward the upper surface 3. The lower surface 7 of the translucent member 2 is provided so as to be joined to the upper surfaces (that is, the light extraction surfaces 11) of the plurality of light emitting elements 10 provided in the light emitting device 1. The translucent member 2 has an upper surface 3 and a lower surface 7 opposite to the upper surface 3. Light emitted from the light emitting element 10 is incident from the lower surface 7, and the surface is smaller than the lower surface 7. discharge. The translucent member 2 is formed as a single plate, and includes an upper surface 3, a first side surface 4 continuous with the upper surface 3, a second upper surface 5 continuous with the first side surface 4, A second side surface 6 continuing to the second upper surface 5 and a lower surface 7 continuing to the second side surface are provided.

  The lower surface 7 of the translucent member 2 is a surface on which light from the plurality of light emitting elements 10 included in the light emitting device 1 is incident. The lower surface 7 is formed to have an area larger than the sum of the areas of the upper surfaces of the light emitting elements 10 bonded to the lower surface 7. The lower surface 7 is formed so that the surface thereof is flat. The lower surface 7 of the translucent member 2 is formed larger than the light extraction surface 11 of the light emitting element 10 so as to include the entire light extraction surface 11 of the light emitting element 10. By forming the lower surface 7 of the translucent member 2 with an area larger than the sum of the upper surface areas of the light emitting elements 10, light emitted from the light emitting elements 10 can be incident without loss. The lower surface 7 is formed to have a large area in the range of 105 to 150% with respect to the sum of the upper surface areas of at least one light emitting element 10 bonded to the lower surface 7.

  Further, the lower surface 7 of the translucent member 2 has such a size that when the adhesive 15 is bonded to the light emitting element 10 with the adhesive 15, the adhesive 15 spreads in a fillet shape on the side surface of the light emitting element 10 to form the fillet 16. Preferably there is. That is, it is preferable that the lower surface 7 of the translucent member 2 has such a size that the end portion of the fillet 16 formed of the adhesive 15 and the end portion of the lower surface 7 coincide with each other. Further, the lower surface 7 of the translucent member 2 has the entire upper surface of the light emitting element 10 even if a slight positional shift occurs when the translucent member 2 and the light emitting element 10 are joined. It is a size which can be covered with the lower surface 7. Therefore, the translucent member 2 hardly changes in luminance due to mounting deviation, and can improve the yield in the manufacturing process. In addition, the lower surface 7 and the upper surface 3 of the translucent member 2 are formed to be flat surfaces parallel to each other. A second side surface 6 is continuously formed on the lower surface 7.

The upper surface 3 of the translucent member 2 serves as a light emitting surface of the light emitting device 1 and emits light incident from the lower surface 7 to the outside. The upper surface 3 is formed to be smaller than the area of the lower surface 7. The translucent member 2 is disposed such that the upper surface 3 is exposed from the light reflective member 20 without being covered by the light reflective member 20. The upper surface 3 is formed so that the surface thereof is flat. The upper surface 3 and the lower surface 7 are substantially similar in plan view, and the upper surface 3 and the lower surface 7 are formed so that their gravity center positions overlap each other. A first side surface is continuously formed on the upper surface 3.
The area of the upper surface 3 of the translucent member 2 is preferably smaller than the sum of the upper surface areas of one or more light emitting elements included in the light emitting device 1. Furthermore, the area of the upper surface 3 of the translucent member 2 is preferably 70% or less and more preferably 50% or less with respect to the area of the lower surface 7 of the translucent member 2. In this way, by narrowing down the area of the upper surface 3, the light emitted from the light emitting element 10 incident from the lower surface 7 of the translucent member 2 is converted into the upper surface 3 having a smaller area (that is, the light emitting surface of the light emitting device 1). Can be released from That is, the light emitting device 1 can illuminate farther with high brightness by reducing the area of the light emitting surface by the translucent member 2.

  The first side surface 4 of the translucent member 2 is formed substantially perpendicular to the upper surface 3. The first side surface 4 is formed substantially perpendicular to the upper surface 3, so that the light reflecting member 20 can be prevented from creeping up to the upper surface 3 when the light emitting device 1 is manufactured. The first side surface 4 has an angle that can suppress the scooping of the light reflective member 20, for example, a range of 90 degrees plus or minus 5 degrees with respect to the upper surface 3, and this range is substantially vertical in this specification. Since the first side surface 4 is formed substantially perpendicular to the upper surface 3, when the upper surface 3 of the translucent member 2 is used as the light emitting surface of the light emitting device 1, the light emitting portion on the upper surface of the light emitting device 1 and non-light emitting The boundary with the department becomes clear. A second upper surface 5 is continuously formed on the first side surface 4.

  The second upper surface 5 of the translucent member 2 is formed with the size of the lower surface area of the lower surface 7. In the present embodiment, the second upper surface 5 is formed so as to be substantially parallel to the upper surface 3 and the lower surface 7. The second upper surface 5 is formed so as to have a curved surface portion at the connection portion with the first side surface 4. Since the second upper surface 5 has a curved surface portion at the connection portion with the first side surface 4, the mechanical strength at the connection portion can be increased, and light attenuation between the second upper surface 5 and the lower surface 7 can be achieved. Can be suppressed. A second side surface 6 is continuously formed on the second upper surface 5.

  The second side surface 6 of the translucent member 2 is formed on a surface substantially perpendicular to the lower surface 7. Since the second side surface 6 is formed substantially perpendicular to the lower surface 7, the adhesive material 15 is rubbed against the side surface when the light-transmitting member 2 and the light-emitting element 10 are joined at the time of manufacturing the light-emitting device 1. The rise can be suppressed. The second side surface 6 can prevent the light emitted from the light emitting element 10 from being lost by suppressing the scooping up of the adhesive 15.

The translucent member 2 is made of a material that can transmit light emitted from the light emitting element 10 and extract the light to the outside. The translucent member 2 has an upper surface 3 exposed from the light reflective member 20 to become a light extraction surface (that is, a light emitting surface) 11 of the light emitting device 1.
The translucent member 2 can contain a light diffusing material or a phosphor capable of converting the wavelength of at least part of light incident from the light emitting element 10. The translucent member 2 containing a phosphor includes, for example, a phosphor, a sintered body of phosphor, and a material in which a phosphor powder is contained in a resin, glass, another inorganic substance, or the like. The sintered body of the phosphor may be formed by sintering only the phosphor, or may be formed by sintering a mixture of the phosphor and a sintering aid. When sintering a mixture of a phosphor and a sintering aid, it is preferable to use an inorganic material such as silicon oxide, aluminum oxide, or titanium oxide as the sintering aid. Thereby, even if the light emitting element 10 has high output, discoloration and deformation of the sintering aid due to light and heat can be suppressed.

The light transmissive member 2 is more preferable as the light transmittance is higher because the light can be easily reflected at the interface with the light reflective member 20 described later, and the luminance can be improved. In addition, when the light output from the light emitting element 10 is large, it is more preferable that the translucent member 2 is comprised only with an inorganic substance.
As for the thickness of the translucent member 2, the dimension from the upper surface 3 to the lower surface 7 is about 50-300 micrometers, for example. Of the thicknesses described above, the height of the second side surface 6 is preferably about 10 to 50% of the height from the upper surface 3 to the lower surface 7, for example. As the height of the second side surface 6 increases, the amount of the light reflecting member 20 disposed above the second upper surface 5 decreases, and there is a risk that light leaks through the light reflecting member 20 around the upper surface 3. is there. Further, as the height is smaller, chipping or the like is likely to occur, and light from the light emitting element 10 is not easily propagated to the upper surface 3.

Moreover, as a fluorescent substance which can be contained in the translucent member 2, a fluorescent substance used in this field can be appropriately selected. Examples of phosphors that can be excited by blue light emitting elements or ultraviolet light emitting elements include yttrium-aluminum-garnet phosphors (YAG: Ce) activated with cerium, and lutetium-aluminum-garnet phosphors (LAG) activated with cerium. : Ce), nitrogen-containing calcium aluminosilicate phosphors activated with europium and / or chromium (CaO—Al ₂ O ₃ —SiO ₂ : Eu), silicate phosphors activated with europium ((Sr, Ba) ₂ SiO ₄ : Eu), β sialon phosphor, CASN phosphor (CaAlSiN ₃ : Eu), SCASN phosphor ((Sr, Ca) AlSiN ₃ : Eu) and other nitride phosphors, KSF phosphor (K ₂ SiF ₆ : Mn), sulfide-based phosphor, quantum dot phosphor, and the like. By combining these phosphors with a blue light emitting element or an ultraviolet light emitting element, light emitting devices of various colors (for example, white light emitting devices) can be manufactured. In the case of the light emitting device 1 capable of emitting white light, the light emitting device 1 is adjusted to be white depending on the type and concentration of the phosphor contained in the translucent member 2. The density | concentration of the fluorescent substance contained in the translucent member 2 is about 5-50 mass%, for example.
Examples of the light diffusing material that can be contained in the translucent member 2 include titanium oxide, barium titanate, aluminum oxide, and silicon oxide.

(Adhesive)
The light emitting element 10 and the translucent member 2 can be joined by the adhesive 15. The adhesive 15 is continuous from the upper surface of the light emitting element 10 to at least a part of the side surface, and is provided between the light reflective member 20 and the side surface of the light emitting element 10. The upper surface of the adhesive 15 interposed between the light reflective member 20 and the side surface of the light emitting element 10 is provided so as to be joined to the lower surface 7 of the light transmissive member 2.
As the adhesive 15, a well-known adhesive such as epoxy or silicone, adhesion with a high refractive index organic adhesive, adhesion with low melting point glass, or the like can be used. Note that the adhesive 15 is more preferably an inorganic adhesive. If the adhesive 15 is an inorganic adhesive, it is difficult to be deteriorated by heat and light, which is particularly convenient when using the light emitting element 10 that emits light with high luminance.
It is preferable that the adhesive material 15 is provided up to the upper side surface together with the upper surface of the light emitting element 10. The adhesive 15 is provided up to the upper side of the light emitting element 10, so that the adhesive 15 spreads between the lower surface 7 of the translucent member 2 and the side surface of the light emitting element 10, and reaches the edge of the lower surface 7 of the translucent member 2. A continuous fillet 16 is formed. The fillet 16 is formed so as to cover the four side surfaces of the light emitting element 10 having a rectangular shape in plan view. Since the adhesive 15 includes the fillet 16, light from the side surface of the light emitting element 10 can be incident on the translucent member 2 and the light extraction efficiency of the light emitting device 1 can be increased. In addition, the fillet 16 is preferably formed up to a position below the center in the height direction on the side surface of the light emitting element 10. The “joining” between the translucent member 2 and the light emitting element 10 may be a direct joining method such as a direct joining method such as pressure bonding, sintering, a hydroxyl group joining method, a surface activated joining method, or an atomic diffusion bonding method. Good.

  As shown in FIGS. 1, 2, and 4, the light reflective member 20 reflects the light that travels to other than the upper surface 3 of the light transmissive member 2 so as to be emitted from the upper surface 3, and also the side surface of the light emitting element 10. The light emitting element 10 is protected from external force, dust, gas, and the like. The light reflecting member 20 exposes the upper surface 3 of the translucent member 2 as a light emitting surface (that is, a light emitting surface) of the light emitting device 1, so that the translucent member 2, the light emitting element 10, and the substrate 30 have an upper surface. It is provided so as to cover the part. Specifically, the light reflective member 20 covers the first side surface 4, the second upper surface 5, the second side surface 6, the side surface of the fillet 16, the side surface and the lower surface side of the light emitting element 10 of the translucent member 2. Is provided. The light extraction surface 11 of the light emitting element 10 is formed so as to allow light to enter the light transmissive member 2 because it is not directly covered with at least the light reflective member 20. The light reflective member 20 is a member that can reflect the light from the light emitting element 10, reflects light from the light emitting element 10 at the interface between the light transmissive member 2 and the light reflective member 20, and transmits the light. The light is incident into the sex member 2. Thus, the light emitted from the light emitting element 10 is reflected by the light reflecting member 20 and passes through the light transmitting member 2, and from the upper surface 3 of the light transmitting member 2 that is the light emitting surface of the light emitting device 1. , Emitted to the outside.

  Here, the height of the upper surface of the light reflective member 20 is preferably equal to or lower than the height of the upper surface 3 of the translucent member 2. The light emitted from the upper surface 3 of the translucent member 2 serving as the light emitting surface has a spread in the lateral direction. Therefore, when the height of the upper surface of the light reflective member 20 is higher than the height of the upper surface 3 of the light transmissive member 2, the light emitted from the upper surface 3 of the light transmissive member 2 is light reflective member 20. The light is reflected to cause variation in light distribution. Therefore, the light reflective member 20 covers the outer periphery of the first side surface 4 of the translucent member 2 and is provided so that the height of the light reflective member 20 is equal to or lower than the height of the upper surface 3. By doing so, it is preferable because the light emitted from the light emitting element 10 can be efficiently taken out of the light emitting device 1.

  The light reflective member 20 includes a light reflective substance in a base material made of a silicone resin, a modified silicone resin, an epoxy resin, a modified epoxy resin, an acrylic resin, or a hybrid resin containing at least one of these resins. Can be formed. As a material of the light reflecting substance, titanium oxide, silicon oxide, zirconium oxide, potassium titanate, alumina, aluminum nitride, boron nitride, mullite, or the like can be used. Since the light reflection member 20 has different amounts of light reflection and transmission depending on the concentration and density of the light reflective material, the concentration and density may be appropriately adjusted according to the shape and size of the light emitting device. Moreover, if the light reflective member 20 is made of a material having both heat reflectivity and heat dissipation, it is possible to improve heat dissipation while providing light reflectivity. Examples of such a material include ceramics, and specifically include aluminum oxide, aluminum nitride, and boron nitride.

  In addition, the light reflective member 20 is good also as a structure provided with two types of light reflective members 21 and 22 from which a linear expansion coefficient differs. That is, the light reflective member 20 is provided with the low linear expansion light reflective member 21 to a height that covers the light emitting element 10 and the substrate 30 and covers the light emitting element 10 and the fillet 16 on the side surface. The light-reflecting member 21 is disposed between the light-emitting element 10 and the substrate 30 as an underfill, and uses a material having a lower linear expansion than the light-reflecting member 22, thereby joining the light-emitting element 10 and the substrate 30. It is possible to relieve stress in the case. Moreover, after providing the light reflective member 21, the light reflective member 22 is provided up to the height of the upper surface of the light transmissive member 2, and the first side surface 4, the second upper surface 5, the second side surface 6, and the light reflective member. 21 is covered.

(substrate)
The substrate 30 has at least one light emitting element 10 mounted thereon, and electrically connects the light emitting device 1 to the outside.
As shown in FIGS. 4 to 6, the substrate 30 includes a flat plate-like support member 31, and conductor wirings 32 to 34 and 36 to 38 disposed on the surface and inside of the support member 31. . Specifically, the substrate 30 includes a positive electrode 32, a negative electrode 33, and an intermediate electrode 34 on the upper surface of the substrate on which the light emitting element 10 is mounted as a conductor wiring. Further, an external connection positive electrode 37 connected to the positive electrode 32 through the via 36 and an external connection negative electrode 38 connected to the negative electrode 33 through the via 36 are provided on the lower surface of the substrate. The positive electrode 32 and the negative electrode 33 on the upper surface of the substrate are each extended from the connection portion with the light emitting element 10 toward the end portion of the substrate, and a part of each is exposed from the light reflecting member 20. By exposing a part of each of the positive electrode 32 and the negative electrode 33 from the light reflective member 20 on the upper surface of the substrate, the exposed region can be used as an external connection electrode of the light emitting device. That is, the light emitting device 1 includes a pair of electrode patterns for external connection on the upper surface side and the lower surface side of the light emitting device. Thus, when the light emitting device 1 is mounted on the secondary mounting substrate, the power supply member to the light emitting device 1 can be connected from either the upper surface or the lower surface of the light emitting device 1 so as to sandwich the upper surface and the lower surface. It becomes possible.

  Further, the substrate 30 includes a heat radiation terminal 39 that is electrically independent from the light emitting element 10 on the lower surface. Note that the substrate 30 has a structure such as the shape and size of the electrode according to the configuration of the electrodes of the light-emitting element 10. Here, the element electrodes provided on the light-emitting element 10 are, for example, three locations (element n electrodes). , Element p-electrode, element n-electrode), it is formed corresponding to the configuration. The heat radiating terminal 39 is formed so as to have an area larger than the sum of the upper surface areas of all the light emitting elements 10 included in the light emitting device 1, and is installed so as to overlap with a region immediately below the light emitting element 10. Yes. The installation of the heat dissipation terminal 39 makes it easy to release heat generated by driving the light emitting element 10 to the outside. Further, the substrate 30 is provided with a cathode mark CM indicating the polarity of the electrode on the upper surface of the substrate.

The support member 31 is preferably made of an insulating material, and is preferably made of a material that hardly transmits light emitted from the light emitting element 10 or external light. Moreover, it is preferable to use a material having a certain degree of strength. Specific examples include ceramics such as alumina, aluminum nitride, and mullite, phenol resins, epoxy resins, polyimide resins, BT resin (bismaleimide triazine resin), polyphthalamide (PPA), and the like. The support member 31 may have a structure having a cavity. Thereby, it can form easily by dripping the above-mentioned light reflective member 20 and hardening | curing.
The conductor wirings 32 to 34, 36 to 38 and the heat radiating terminal 39 are provided on the surface or inside of the support member 31, for example, Cu, Ag, Au, Al, Pt, Ti, W, Pd, Fe, Ni, etc. It can be formed using a metal or an alloy containing these. Such a conductor wiring can be formed by electrolytic plating, electroless plating, vapor deposition, sputtering, or the like.

  Since the light emitting device 1 has the above-described configuration, as an example, when the light emitting device 1 is used as a headlight of a vehicle such as a motorcycle or an automobile or a vehicle such as a ship or an aircraft, the light emitted from the light emitting element 10 is emitted. It can irradiate further. That is, as shown in FIG. 7, in the light emitting device 1, when light is emitted from one or more light emitting elements 10, the light propagates through the light transmissive member 2 without being reflected by the light reflective member 20. There are light that goes directly to the upper surface 3 and light that is reflected by the light reflective member 20 and exits from the upper surface 3. And in the light-emitting device 1, since the area of the lower surface 7 of the translucent member 2 is larger than the sum of the upper surface area of the light emitting element 10, the light irradiated from the light emitting element 10 can be received without loss. In the light emitting device 1, the light that is reflected through the light reflecting member 20 and is emitted from the upper surface 3 together with the light that is directly emitted from the upper surface 3 of the translucent member 2 is sent from the light emitting element 10 without loss. Furthermore, since the area of the upper surface 3 of the translucent member 2 is smaller than the sum of the upper surface areas of the light emitting elements 10 and smaller than the area of the lower surface 7 of the translucent member, the emitted light from the light emitting elements 10 is The light transmitting member 2 collects the upper surface 3. Thereby, it can be set as the light-emitting device 1 suitable for the high beam use etc. of a headlight, which can irradiate light far away with high brightness. In FIG. 7, typical light irradiation directions are schematically indicated by arrows.

  Moreover, in the light-emitting device 1, since the joining area of the translucent member 2 and the light reflective member 20 becomes large, the heat dissipation of the translucent member 2 can be improved. Further, in the light emitting device 1, the second upper surface 5 and the second side surface 6 of the translucent member 2 are locked by the light reflective member 20, and the translucent member 2 is hardly peeled off. Therefore, in the light emitting device 1, when the phosphor is contained in the translucent member 2, the light emitting element 10 and the translucent member are maintained by maintaining the posture of the translucent member 2 at the initial setting. 2 does not change, and the light emission color unevenness of the light emitting device 1 hardly occurs.

[Method for Manufacturing Light Emitting Device]
Next, a method for manufacturing the light emitting device will be described with reference to FIGS. 8A to 8F.
(Preparation process of substrate)
First, as shown in FIGS. 8A, 5 and 6, a substrate 30 is prepared. The substrate 30 includes a plate-like support member 31 having a rectangular shape in plan view, conductor wirings 32 to 34 and 36 to 38, and a heat dissipation terminal 39. On the upper surface of the support member 31, a positive electrode 32, a negative electrode 33, and an intermediate electrode 34 are formed as conductor wirings for mounting the light emitting element 10. An external connection positive electrode 37 and an external connection negative electrode 38 are formed on the lower surface of the support member 31 as conductor wiring. A heat radiation terminal 39 is formed between the external connection positive electrode 37 and the external connection negative electrode 38. In the present embodiment, the substrate 30 is provided with the cathode mark CM made of the same material as the electrode material such as the positive electrode 32 along one corner of the upper surface of the substrate.

(Light emitting element mounting process)
As shown in FIG. 8B, one or more light emitting elements 10 are mounted on the substrate 30. Here, the two light emitting elements 10 are mounted on the substrate 30 via connection members such as bumps BP. The two light emitting elements 10 are aligned and arranged so as to have a rectangular shape in plan view as a whole. The interval between the two light emitting elements 10 is preferably an interval at which a fillet 16 of the adhesive 15 to be described later is continuously formed between the light emitting elements 10. Specifically, when the light emitting device 1 includes two or more light emitting elements 10, the distance between adjacent light emitting elements 10 is preferably not more than twice the thickness of the light emitting elements 10.

(Adhesive supply process)
As shown in FIG. 8C, the adhesive 15 is dropped on the upper surface of the light emitting element 10. The dropped adhesive material 15 is pressed by the translucent member 2 and spreads over the side surface of the light emitting element 10 to form a fillet 16. The amount and viscosity of the adhesive 15 to be dropped are appropriately adjusted so that a fillet can be formed on the side surface of the light emitting element 10 and the adhesive 15 does not wet and spread to the substrate 30.

(Joint process of translucent member)
As shown in FIG. 8D, the translucent member 2 has the lower surface of the translucent member 2 bonded to the light emitting element 10 via an adhesive 15 disposed on the upper surface of the light emitting element 10. The translucent member 2 is formed of, for example, an inorganic material, so that the light-emitting device 1 can be highly reliable with little deterioration due to light and heat. The translucent member 2 is formed such that the area of the lower surface 7 is larger than the sum of the upper surface areas of the one or more light emitting elements 10, and the distance from the side surface of the light emitting element 10 to the outer edge of the lower surface 7 of the translucent member 2. Are preferably arranged so as to be equivalent. In addition, the center of gravity of the translucent member 2 is arranged so that the center of the upper surface 3 overlaps the entire center of gravity of the one or more light-emitting elements 10 arranged so as to be rectangular in plan view as a whole. It is preferred that In the translucent member 2 bonded to the light emitting element 10, the area of the lower surface 7 is larger than the sum of the upper surface areas of the light emitting element 10. Therefore, in the translucent member 2, the fillet 16 is formed by the adhesive 15 over the width portion of the difference in size that protrudes to the side from the side surface of the light emitting element 10. The fillet 16 is also formed on the opposing side surfaces of the two light emitting elements 10 and is formed on all four side surfaces of the light emitting element 10.

(Supplying process of light reflecting member)
As shown in FIGS. 8E and 8F, a light reflective member 20 that covers the light emitting element 10, the translucent member 2, and the substrate 30 is provided. The light emitting device 1 according to this embodiment includes two types of light reflective members 21 and 22 as the light reflective member 20.
(First supply process)
First, the light reflective member 21 is supplied to a height that covers the space between the light emitting element 10 and the substrate 30 and the light emitting element 10 and the fillet 16 on the side surface. Since the light reflective member 21 is disposed between the light emitting element 10 and the substrate 30 as an underfill, it is preferable to use a material having a lower linear expansion than the light reflective member 22. Thereby, the stress at the joint between the light emitting element 10 and the substrate 30 can be relaxed.
(Second supply process)
Next, the light reflective member 22 that covers the first side surface 4, the second upper surface 5, and the second side surface 6 of the translucent member 2 is supplied. At this time, the supply of the light reflective member 22 is preferably dropped onto the upper surface of the substrate 30 spaced from the light transmissive member 2 so that the upper surface 3 of the light transmissive member 2 is exposed from the light reflective member 22. The light reflective member 22 covers the surface of the light reflective member 21.
As the light reflecting members 21 and 22, for example, a so-called white resin in which titanium oxide is contained in a silicone resin is used here.

(Individualization process)
After the light reflective member 20 is formed, the substrate 30 is cut for each unit of the light emitting device, and the light emitting device 1 is formed. The light emitting device 1 includes at least one or more light emitting elements 10, and may be three, four, five or more, or one. The light-emitting device 1 manufactured by each process as described above allows light emitted from one or more light-emitting elements 10 to enter from the lower surface 7 of the translucent member 2 larger than the sum of the upper surface areas of the light-emitting elements 10 without loss. The light can be emitted from the upper surface 3 smaller than the lower surface 7 of the translucent member 2 to the outside as light having high luminance.

Next, the second to fourth embodiments will be described with reference to FIGS. 9A to 9C. In the second embodiment to the fourth embodiment, the configuration other than the shape of the translucent member is the same as that of the first embodiment, and thus description thereof is omitted as appropriate.
Second Embodiment
As shown in FIG. 9A, the translucent member 2A is formed in a convex shape from the lower surface 7A toward the upper surface 3A. The translucent member 2A includes an upper surface 3A, a first side surface 4A, a second upper surface 5A, a second side surface 6A, and a lower surface 7A. The translucent member 2A is different from the translucent member 2 of the first embodiment in that the connecting portion between the first side surface 4A and the second upper surface 5A is formed at a right angle. Even if the translucent member 2A has the first side surface 4A and the second upper surface 5A formed at right angles, the light emitting device can achieve the same effects as the first embodiment described above.

<Third Embodiment>
As shown in FIG. 9B, the translucent member 2B is formed in a convex shape from the lower surface 7B toward the upper surface 3B. The translucent member 2B includes a flat and flat upper surface 3B, a first side surface 4B that is continuous with the upper surface 3B and substantially perpendicular to the upper surface 3B, and an inclined surface 8B that is continuously inclined with respect to the first side surface 4B. A second upper surface 5B formed continuously in parallel with the upper surface 3A continuously with the inclined surface 8B, and a second side surface 6B substantially continuous with the second upper surface 5B and substantially perpendicular to the second upper surface 5B, The second side surface 6B is provided with a lower surface 7B substantially parallel to the upper surface 3B. And the translucent member 2B differs from the translucent member 2 of 1st Embodiment by the point which has the inclined surface 8B between the 1st side surface 4B and the 2nd upper surface 5B. For example, the inclined surface 8B is formed to be inclined with respect to the second upper surface 5B in an angle range of 10 to 60 degrees. Since the translucent member 2B includes the inclined surface 8B, the light from the light-emitting element 10 can be efficiently transmitted toward the upper surface 3B with a reduced number of reflections, and a light-emitting device with high luminance can be obtained. .

<Fourth embodiment>
As shown in FIG. 9C, the translucent member 2C is formed in a convex shape from the lower surface 7C toward the upper surface 3C. The translucent member 2C has a flat and horizontal upper surface 3C, a first side surface 4C that is continuous with the upper surface 3C and substantially perpendicular to the upper surface 3C, and a concave shape that is continuous with the first side surface 4C. A curved surface 8C, a second upper surface 5C that is continuous to the curved surface 8C and substantially parallel to the upper surface 3C, and a second side surface 6C that is continuous to the second upper surface 5C and substantially perpendicular to the second upper surface 5C. The lower surface 7C is continuous with the second side surface 6C and substantially parallel to the upper surface 3C. The translucent member 2C is different from the translucent member 2 of the first embodiment in that the translucent member 2C has a curved surface 8C formed over a wide range between the first side surface 4C and the second upper surface 5C. The curved surface 8C is configured such that the first side surface 4C and the second upper surface 5C are continuous as, for example, an arc curve that is convex inward. Since the translucent member 2C includes the curved surface 8C, the light from the light emitting element 10 can be efficiently transmitted toward the upper surface 3B by reducing the number of reflections, and a light emitting device with high luminance can be obtained. In addition, the presence of the curved surface 8C can alleviate stress concentration and improve the structural strength of the translucent member 2C.

<Fifth Embodiment>
Next, a fifth embodiment will be described with reference to FIGS. Note that in the fifth embodiment, configurations other than the items described below are the same as those in the first embodiment, and thus the description thereof is omitted.

  As shown in FIGS. 10 and 11, in the light emitting device 1D, as the light reflecting member 20D, a resin (light reflecting member) 22D containing a light reflecting substance and a ceramic (light reflecting member) 23 having light reflectivity are used. Are included. The ceramics 23 is provided around the upper surface 3 of the light transmissive member 2 in a plan view of the light reflective member 20D and the light transmissive member 2 as viewed from above. When a material (for example, resin) containing an organic substance is provided in a region in contact with the translucent member 2, there is a possibility that cracking may occur in the region in contact with the translucent member 2 of the light reflective member 20D due to high-density light. . In particular, when a crack occurs around the upper surface 3 of the translucent member 2 that is the periphery of the light emitting surface of the light emitting device 1, light escapes from the crack and the luminance of the light emitting device 1 decreases. Therefore, in this embodiment, the ceramic 23 having excellent light resistance is provided around the light emitting surface of the light emitting device 1D so as to be adjacent to the light emitting surface (upper surface 3), so that cracking occurs around the translucent member 2. Can be suppressed, and the light-emitting device 1D having high luminance can be obtained. Moreover, since the ceramic 23 is a material having higher heat dissipation than that of the resin, the heat dissipation from the translucent member 2 can be improved.

  As shown in FIG. 11, the first side surface 4 and the second upper surface 5 are covered with ceramics 23, and the second side surface 6 is covered with a resin 22D containing a light reflecting material. As shown in FIG. 10, the resin 22 </ b> D containing the light reflecting material is provided so as to surround the ceramic 23 in the plan view. The light reflecting member 20 </ b> D includes a ceramic 23 and is separate from the resin (light reflecting member) 22 </ b> D containing a light reflecting substance, and the ceramic 23 is placed around the upper surface 3 of the light transmissive member 2. It is supposed to be provided in an adjacent state.

<Sixth Embodiment>
Next, a sixth embodiment will be described with reference to FIG. Note that in the sixth embodiment, configurations other than the items described below are the same as those in the fifth embodiment, and a description thereof will be omitted. In the light emitting device 1E, the reflective film 25 is provided around the upper surface 3 of the translucent member 2 in plan view. Specifically, as shown in FIG. 12, in the light emitting device 1E, a reflective film 25 is provided on the upper surface of the ceramic 23 having reflectivity. Thereby, even if the ceramic 23 transmits a part of the light, the light that passes through the ceramic 23 can be reflected by the reflective film 25, so that a reduction in luminance of the light emitting device 1 can be reduced. As the reflective film 25, a metal can be used, for example, titanium or nickel can be used. Thus, by providing the reflective film 25 on the upper surface of the ceramics 23, it is possible to maintain a high luminance and to have excellent heat dissipation.

<Seventh embodiment>
Next, a seventh embodiment will be described with reference to FIG. Note that in the seventh embodiment, configurations other than the items described below are the same as those in the fifth embodiment, and a description thereof will be omitted. FIG. 13 is a cross-sectional view schematically showing the light-reflecting member 20F provided in a rectangle cut from the center in the short direction in the longitudinal direction. In the seventh embodiment, the ceramic 23F described in the fifth embodiment covers the first side surface 4, the second upper surface 5, and the second side surface 6 of the translucent member 2 as shown in FIG. The configuration is provided with an expanded range. At this time, the ceramic 23 </ b> F is provided up to the outer periphery of the second upper surface 5 of the translucent member 2 in plan view. The resin 22 or the light reflecting member 21 containing the light reflecting material may be provided at least on the side surface of the fillet 16, the side surface and the lower surface side of the light emitting element 10. Here, the side surface of the ceramic 23F is provided so as to cover the resin 22 containing the light reflecting material. Thus, in the light emitting device 1F, the heat dissipation can be further improved by widening the range in which the ceramic 23F is provided.

<Eighth Embodiment>
Next, an eighth embodiment will be described with reference to FIG. Note that in the eighth embodiment, configurations other than the items described below are the same as in the seventh embodiment, and a description thereof is omitted. In the eighth embodiment, the reflective film 25G is provided in the seventh embodiment as in the sixth embodiment. As shown in FIG. 14, in the light emitting device 1G, the ceramic 23F is provided to the outside of the outer periphery of the second upper surface 5 of the translucent member 2 in a plan view, and a reflective film 25G is formed on the upper surface of the ceramic 23F. ing. Thus, by forming the reflective film 25G on the ceramic 23F, it is possible to reduce a decrease in luminance. The reflective film 25G has the same configuration as that described in the sixth embodiment.

  In the fifth embodiment and the seventh embodiment, the ceramics 23 and 23F are formed in a shape provided in advance on the translucent member 2. When the reflective films 25 and 25G are provided as in the sixth embodiment and the eighth embodiment, a mask is provided on the upper surface of the translucent member 2 and is formed by sputtering or the like.

In FIG. 15, in the light emitting device 1, the areas of the upper surface and the lower surface for the respective luminances of the translucent member 2 described in the first embodiment and the translucent member 2 </ b> B described in the third embodiment. The results of measurement with different ratios are shown.
As shown in FIG. 15, the upper surface and the lower surface have an area ratio of 100%, that is, the translucency in which the upper surface is smaller than the lower surface than the light emitting device using the translucent member in which the upper surface and the lower surface have the same area. It can be seen that the luminance is improved in the light emitting device using the members 2 and 2B.
Specifically, assuming that the luminance of the light emitting device using the translucent member having the same area on the upper surface and the lower surface is 100%, the translucent members 2 and 2B whose upper surface is about 70% of the area of the lower surface are obtained. The luminance of the light emitting device used is about 120%, and the luminance of the light emitting device using the translucent members 2 and 2B whose upper surface is about 50% of the area of the lower surface is improved to about 140%.

  The translucent members 2, 2 </ b> A to 2 </ b> C provided in the light emitting device described above form irregularities on the upper surface 3, 3 </ b> A to 3 </ b> C and the lower surface 7, 7 </ b> A to 7 </ b> C, and the upper surface 3, 3 </ b> A to 3 </ b> C has a lens function. As such, it may be a curved surface. The unevenness formed on the lower surfaces 7 and 7A to 7C of the translucent members 2 and 2A to 2C can scatter incident light from the light emitting element 10, and luminance unevenness and color unevenness are easily reduced. In particular, when a plurality of light emitting elements 10 are bonded to one translucent member 2, 2A to 2C, the influence of the arrangement of each light emitting element 10 and the influence of light distribution, luminance unevenness, and color unevenness are reduced. Therefore, it is preferable.

Furthermore, you may make fluorescent material, a light-diffusion material, etc. contain in the adhesive material 15 which joins the translucent member 2, 2A-2C, and the light emitting element 10. FIG.
Moreover, although 1st Embodiment demonstrated as a structure by which the two light emitting elements 10 were mounted on the board | substrate 30, the mounting number of the light emitting elements 10 is not limited to this, The desired light-emitting device It can be appropriately changed according to the size of 1 and the required luminance. In the case where a plurality of light emitting elements 10 are mounted, the translucent members 2, 2 </ b> A to 2 </ b> C may be bonded to each of the light emitting elements 10, or one light transmitting element may be bonded to the plurality of light emitting elements 10. The members 2 and 2A to 2C may be joined.

  In the light emitting device 1 according to the present invention, a protective element such as a Zener diode may be mounted on the substrate 30. By embedding these protective elements in the light-reflecting member 20, it is possible to prevent a decrease in light extraction due to the light from the light emitting element 10 being absorbed by the protective element or shielded by the protective element. . Furthermore, it is needless to say that the configurations shown in FIGS. 9A to 9C exemplified for the light emitting device 1 according to the present invention can be similarly applied to the light emitting devices 1D to 1G.

  The light emitting device of the present invention can be used as a light source for headlights of vehicles such as motorcycles and automobiles or vehicles such as ships and aircrafts. In addition, it can be used for various light sources such as various illumination light sources such as spotlights, display light sources, and in-vehicle components.

1, 1D to 1G Light emitting device 2 Translucent member 2A, 2B, 2C Translucent member 3, 3A, 3B, 3C Upper surface 4, 4A, 4B, 4C First side surface 5, 5A, 5B, 5C Second upper surface 6 , 6A, 6B, 6C Second side surface 7, 7A, 7B, 7C Lower surface 8B Inclined surface 8C Curved surface 10 Light emitting element 11 Light extraction surface 15 Adhesive 16 Fillet 20, 20D, 20E, 20F Light reflecting member 21 Light reflecting Material (underfill)
22 Light reflective member 23, 23F Light reflective member (ceramics)
25, 25G Reflective film 30 Substrate 31 Support member 32 Conductor wiring (positive electrode)
33 Conductor wiring (negative electrode)
34 Conductor wiring (intermediate electrode)
36 Conductor wiring (via)
37 Conductor wiring (externally connected positive electrode)
38 Conductor wiring (external connection negative electrode)
39 Terminal for heat dissipation CM Cathode mark BP Bump

Claims (14)

One or more light emitting elements having an upper surface as a light extraction surface;
A translucent member having a lower surface bonded to the upper surface of the light emitting element, and an upper surface that emits light emitted from the light emitting element from the lower surface and emits the light to the outside ;
A light reflective member that exposes an upper surface of the light transmissive member and covers a surface of the light transmissive member and a side surface of the light emitting element;
The translucent member is formed in a convex shape from the lower surface of the translucent member toward the upper surface of the translucent member, and is continuous with the upper surface of the translucent member; and the translucent member A second side surface continuous with the lower surface of the member, and a second upper surface continuous with the first side surface and the second side surface of the translucent member,
The first side surface of the translucent member has a surface substantially perpendicular to the upper surface of the translucent member;
The second side surface of the translucent member has a surface substantially perpendicular to the lower surface of the translucent member,
The translucent member has an upper surface area of the light-transmitting member is smaller than the sum of the upper surface area of one or more of the light emitting element, the lower surface area of the light transmitting member, one or more of the light emitting element much larger than the sum of the top surface area of,
The light reflecting member includes a ceramic provided around the upper surface of the translucent member in plan view, and the ceramic covers the first side surface and the second upper surface of the translucent member .   The light emitting device according to claim 1, wherein an upper surface area of the translucent member is 50% or less of the lower surface area of the translucent member. The translucent member is formed by one piece,
3. The light emitting device according to claim 1, wherein when there are a plurality of the light emitting elements, an upper surface of the plurality of light emitting elements and a lower surface of the single light transmitting member are joined.   The light-emitting device according to any one of claims 1 to 3, wherein the translucent member is an inorganic substance. The light emitting element and the translucent member are joined with an adhesive,
The adhesive material is continuous with at least a part of the side surface from the upper surface of the light emitting element, and is provided between the light reflective member and the side surface of the light emitting element.
The upper surface of the adhesive material interposed between the light reflecting member and the side surface of the light emitting element is provided so as to be joined to the lower surface of the light transmitting member. The light emitting device according to 1.   The light emitting device according to claim 5, wherein an end of the lower surface of the translucent member and an end of the adhesive coincide with each other. The light emitting device according to claim 5, wherein the adhesive is an inorganic adhesive.   The light emitting device according to claim 1, wherein the second upper surface of the light transmissive member has a curved surface at a connection portion with the first side surface of the light transmissive member. The light emitting element is mounted on the substrate, the substrate, the region directly under the light-emitting element, any one of claims 1 to 8 having a heat radiating terminal is greater than the sum of the top surface area of the light emitting element The light emitting device according to 1. The light emitting device according to any one of claims 1 to 9 , wherein the light emitting element is mounted on a substrate and includes a pair of electrode patterns on an upper surface and a lower surface of the substrate. 11. The light emitting device according to claim 1, wherein the light reflective member includes ceramics provided around the upper surface of the light transmissive member in a plan view.   The said translucent member as described in any one of Claims 1-11 containing a fluorescent substance.   The light emitting device according to any one of claims 1 to 10, wherein a reflective film is provided on an upper surface of the ceramic.   The light emitting device according to claim 13, wherein the reflective film is a metal film.

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