JP2009164157A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device which exhibits excellent extraction efficiency of light by controlling absorption of light emitted from a light-emitting element by other members. <P>SOLUTION: A light-emitting device comprises a substrate on which conductor wiring is arranged, a light-emitting element mounted on the substrate, light reflecting resin arranged around the light-emitting element and reflecting light emitted therefrom, and a conductive wire for connecting the conductor wiring and the light-emitting element conductively, wherein the conductive wire is buried in the light reflecting resin at least partially. With such an arrangement, light being absorbed by the wire can be reduced. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light-emitting device that can be used for a display device, a lighting fixture, a display, a backlight light source of a liquid crystal display, and the like, and more particularly, to a light-emitting device with high reliability even when a high-power semiconductor light-emitting element is mounted.

  In recent years, various light-emitting devices using semiconductor light-emitting elements (hereinafter also simply referred to as light-emitting elements) have been developed, and means for improving output are being studied.

  For example, Patent Document 1 describes that a high illuminance is obtained by mounting a reflector as close to the light emitting element as possible between the light emitting element and a wiring land provided on the substrate.

JP 2004-265979 A.

  However, even if the reflector as described above is provided, a certain distance exists between the light emitting element and the reflector. For this reason, the light extraction efficiency tends to decrease. Further, by providing such a reflector, it is difficult to reduce the size, and the size of the light emitting device itself is limited. Further, when a gold wire is used as a method of electrically connecting the light emitting element and each terminal (conductor wiring), this gold has a property of absorbing light from the light emitting element, and a reflector as described above is provided. And the longer the wire, the more light is absorbed and the output is reduced.

  Moreover, since the light emitting diode which is a light emitting element is a bipolar element, it is necessary to provide an insulating part between positive and negative wiring lands (conductor wiring) provided on the substrate. Generally, this insulating portion can be easily provided by exposing an insulating substrate material such as a substrate. However, this insulating substrate material has various restrictions such as efficient package production and securing of mechanical strength, and optical characteristics (light reflectance and light absorption rate) are not necessarily intended. The fact is that no material with the characteristics is used.

  In order to achieve the above object, the light emitting device of the present invention includes a substrate on which conductor wiring is disposed, a light emitting element placed on the substrate, and an optical element, and reflects light from the light emitting element. And a conductive wire for conducting the conductor wiring and the light emitting element, and at least a part of the conductive wire is embedded in the light reflecting resin. Thereby, the light absorbed by the wire can be reduced.

  According to a second aspect of the present invention, there is provided a light emitting device that includes a substrate on which conductor wiring is disposed, a light emitting element placed on the conductor wiring, and a light emitting element that is disposed around the light emitting element and reflects light from the light emitting element. And the substrate has an exposed region exposed from the conductor wiring, and the exposed region is at least partially embedded in the light reflecting resin. Thereby, the loss of light due to the exposed region of the substrate can be reduced.

  According to a third aspect of the present invention, there is provided a light emitting device comprising: a substrate on which conductor wiring is disposed; a light emitting element placed on the conductor wiring; a protection element placed on the conductor wiring; And a light reflecting resin that reflects light from the light emitting element, and at least a part of the protective element is embedded in the light reflecting resin. Thereby, absorption of the light by a protection element can be reduced.

  The light emitting device according to claim 4 of the present invention is characterized in that the substrate has an exposed region exposed from the conductor wiring, and at least a part of the exposed region is embedded in the light reflecting resin. According to a fifth aspect of the present invention, there is provided a light emitting device having a protective element that is electrically connected to a conductor wiring, wherein at least a part of the protective element is embedded in the light reflecting resin. Thus, the light extraction efficiency can be improved by embedding a member that absorbs or transmits light from the light emitting element in the light reflecting resin.

  According to the present invention, since the light reflecting member can be provided in the vicinity of the light emitting element, the light from the light emitting element can be reflected efficiently, and even when a conductive wire is used, light absorption by the light reflecting element can be performed. Can be suppressed. Further, light absorption and transmission loss due to the substrate exposed from the conductor wiring can be suppressed, and the light extraction efficiency can be improved. Furthermore, when a protective element is used, light absorption by the protective element can be suppressed.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the form shown below illustrates the light-emitting device for embodying the technical idea of the present invention, and the present invention does not limit the light-emitting device to the following.

  Further, the present specification by no means specifies the member shown in the claims as the member of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention only to the extent that there is no specific description. It is just an example. It should be noted that the size and positional relationship of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

  1A is a perspective view showing a light-emitting device 100 in the present embodiment, FIG. 1B is a partial cross-sectional perspective view in the X-X ′ cross section of FIG. 1A, and FIG. 1C is a top view of FIG. 1A. In the present embodiment, the light emitting device 100 includes a substantially rectangular substrate 101 having conductor wirings 103A, 103B, and 103C disposed on the upper surface, and a plurality of light emitting elements 104 mounted on the conductor wiring 103A. ing. Around these light emitting elements 104, a light reflecting resin 102 for reflecting light from the light emitting elements is provided, and conductive wires 103A, 103B and the light emitting elements 104 are electrically connected (electrically connected). 105. The conductor wiring 103C is made of the same material as the conductor wirings 103A and 103B functioning as electrodes, but is not electrically connected, and is provided as a mark (cathode mark / anode mark) indicating the polarity of the light emitting device.

  The present invention is characterized in that at least a part of the conductive wire 105 is embedded in a light reflecting resin. Thereby, the output can be improved by minimizing the exposure of the conductive wire and suppressing the absorption of light.

(Light reflecting resin)
In the present embodiment, the light reflecting resin 102 reflects light from the light emitting element 104 and is provided so as to surround the light emitting element, and at least partially embeds the conductive wire 105. Thereby, absorption of the light by a conductive wire can be suppressed and light can be extracted efficiently.

  As shown in FIG. 1B, one of the conductive wires connected from the light emitting element 104 is connected to the conductor wiring 103A, and the other is connected to the conductor wiring 103B. The conductor wiring 103A is formed so that the region where the light emitting element is placed and the region where the conductive wire is connected are continuous at a portion embedded in the light reflecting resin 102 (not shown). A portion of the conductive wire 105 connected to the conductor wirings 103 </ b> A and 103 </ b> B is embedded in the light reflecting resin 102. Such a configuration can be obtained by providing the light reflecting resin 102 after the conductive wire 105 is connected to the conductor wirings 103A and 103B. Here, the light reflecting resin 102 is provided so as to cover the connection portion between the conductive wire 105 and the conductor wirings 103A and 103B. However, the present invention is not limited to this. For example, the conductive wire in a region other than the joint portion is provided. May be provided between the joint portion and the light emitting element so as to be embedded. Moreover, it is not necessary to embed all the conductive wires to be used. For example, as shown in FIG. 1A, only the conductive wires directly connected to the conductor wiring among the plurality of conductive wires 105 are embedded. It can be.

  Further, in the present embodiment, at least a part of the substrate exposed from the conductor wiring, that is, the substrate exposed without the conductor wiring (hereinafter referred to as an exposed region) is formed on the light reflecting resin. It is characterized by being buried.

  For example, as shown in FIG. 1B, an exposed region 101A of the substrate that is exposed between the conductor wiring 103A on which the light emitting element is placed and the conductor wiring 103B to which the conductive wire is bonded is embedded with a light reflecting resin 102. By doing so, light transmitted / absorbed through the substrate 101 can be suppressed. In consideration of mechanical strength and workability, the substrate material uses an insulating member such as ceramic. At this time, light from the light emitting element is transmitted through a portion where no conductor wiring is provided. May end up. The substrate side is different from the direction in which light is emitted as the light emitting device, that is, the upward direction in FIG. 1A and the like, and it is not preferable that light is transmitted in such a direction. The light is lost and the extraction efficiency decreases. In the present invention, as the light reflecting resin, at least a material having a light transmittance lower than that of the substrate and a material having a high light reflectance from the light emitting element are selected as materials, and the exposed region of the substrate is selected by the light reflecting resin. By providing it so as to be buried (covered), it is possible to reduce a loss due to transmission of light in a non-target direction. Also, when using a substrate that absorbs light, such as a dark ceramic, the exposed region is covered with a light reflecting resin, that is, embedded to reduce absorption, resulting in improved light extraction efficiency. Can be improved.

  When the exposed region as described above is embedded with the light reflecting resin, an effect can be obtained even when the light emitting element and the conductor wiring are connected without using the conductive wire. For example, in the case of a light-emitting element made of a nitride-based semiconductor using a sapphire substrate, an electrode is formed on the same surface side. Therefore, as shown in FIG. 1A, at least two conductive elements are used for one light-emitting element. A wire is required, but when this electrode is faced down and connected to a conductor wiring using a metal bonding member or the like, connection is possible without a conductive wire. In such a case, since the exposed region of the substrate, that is, the insulating portion is formed immediately below the light emitting element, the light reflecting resin can be provided also in this exposed region.

  In the case where a conductive wire is used as shown in FIG. 1A or the like, it is preferable to bury at least a part of the conductive wire and at least a part of the exposed region of the substrate. In particular, by embedding with the same light reflecting resin, effects such as simplification of the process can be obtained. However, it does not matter if it is provided in a separate process.

  Further, the light reflecting resin may embed a protective element, an integrated circuit, or the like. As a result, light scattering and absorption are reduced, and it is not necessary to separately provide a mounting region for these members, so that the light emitting device itself can be downsized. A light-emitting device using a protective element will be described with reference to FIG.

  FIG. 3 is a partial cross-sectional view of a light emitting device 300 using a protection element. The appearance of the light emitting device 300 is the same shape as that of FIG. 1A, and the shape of the light reflecting resin 302 is the same shape as the light reflecting resin of the light emitting device 100 shown in FIG. 1A, and a part of the cross section can be observed. It is illustrated as follows. As shown in FIG. 3, the light emitting device 300 is provided with conductor wirings 303 </ b> A and 303 </ b> B on a substrate 301. The light emitting element 304 is placed on the conductor wiring 303A and is connected to the conductor wirings 303A and 303B using the conductive wire 305. The protection element 307 is placed on the conductor wiring 303B, fixed by a conductive bonding member, and connected to the conductor wiring 303A using a conductive wire. A light reflecting resin 302 is provided so as to embed the protection element 307.

  Here, the entire protective element 307 is provided so as to be embedded in the light reflecting resin 302. With such a structure, absorption of light from the light emitting element 304 can be suppressed. In addition, you may coat | cover at least one part instead of the whole protective element. Moreover, it is preferable that the conductive wire connecting the protective element and the conductor wiring is also embedded in the light reflecting resin.

  The light reflecting resin for embedding the protective element is preferably provided so as to fill at least part of the conductive wire connecting the light emitting element and the conductor wiring. Moreover, it is preferable that at least a part of the exposed region of the substrate is filled together. Furthermore, it is preferable to provide a light reflecting resin so as to embed at least part of the conductive wire, at least part of the exposed region of the substrate, and at least part of the protective element.

  As described above, a member that absorbs light from the light emitting element (conductive wire, protective element, substrate) or a member that transmits light in a direction other than the target direction ((translucent) substrate) is used as the light reflecting member. By being embedded, it is possible to suppress a reduction in light extraction efficiency.

  The light reflecting member as described above may be provided in a region irradiated with light from the light emitting element, and is provided so as to surround the periphery of the light emitting element. The height of the light reflecting resin will be described with reference to FIG.

  4A is a perspective view of the light emitting device 400 using the sealing member 406, FIG. 4B is a cross-sectional view taken along the line YY ′ in FIG. 4A, and FIG. 4C is a cross-sectional view taken along the line ZZ ′ in FIG. Show. The light emitting device 400 shown in FIG. 4A has the same arrangement of light emitting measures as the light emitting device 100 shown in FIG. 1A and conductive wires, and these are embedded in the sealing member 406. Shall.

  As shown in FIGS. 4A and 4B, the light emitting device 400 has conductor wirings 403A and 403B on a substrate 401. The light emitting element 404 is placed on the conductor wiring 403A and the conductive wire 405 is disposed. Is connected to the conductor wiring 403B (also connected to the conductor wiring 403A, but not shown in the cross-sectional view). A light reflecting resin 402 is provided around the light emitting element 404, and a region surrounded by the light reflecting resin 402 is filled with a sealing member 406.

  The height of the light reflecting resin is preferably at least equal to or higher than the light emitting layer of the light emitting element. Moreover, when using a conductive wire, it is preferable to make it higher than the highest part of the conductive wire 405, as shown to FIG. 4B.

  In addition, when the sealing member 406 is filled in the region surrounded by the light reflecting resin 402, the height of the light reflecting resin is set so that the highest portion of the conductive wire 405 is covered by the filled sealing member 406. adjust. In particular, when the sealing member 406 is filled by a method such as dropping a liquid resin, it is preferable to set the height so that the liquid resin does not overflow from the light reflecting resin around the light emitting element. . However, when the sealing member is formed by a method such as compression molding or printing application, the sealing member may be filled outside the light reflecting resin around the light emitting element.

  Further, as shown in the cross-sectional view of FIG. 4C, the light reflecting resin 402 has a certain height (height substantially parallel to the main surface of the substrate) with respect to the main surface (upper surface, lower surface) of the substrate 401. Is preferable. However, the shape is not limited to this, and other shapes are preferable depending on the method of forming the light reflecting resin.

  For example, the light emitting device 500 shown in FIG. 5 is a cross-sectional view of a portion of the light reflecting resin corresponding to the ZZ ′ cross section of FIG. 4A, not the light reflecting resin 402 having a certain height as shown in FIG. 4C. The light-reflecting resin 502 has a shape in which a part thereof is partially raised. Specifically, among the light reflecting resins 402 of the light emitting device 400 shown in FIG. 4A, the light reflecting resin 502B corresponding to the position where the light reflecting resin in the vertical direction and the light reflecting resin in the horizontal direction intersect with each other is used. It is slightly higher than the light reflecting resin 502A in the region.

  The light reflecting resin having such a shape that a part is raised is formed by a method in which a resin having high viscosity is ejected from a nozzle and applied (drawn) in a vertical direction and a horizontal direction on a substrate before division. Can be obtained. In particular, in the case of a light emitting element having a protective element 307 as shown in FIG. 3, the protective element is disposed in a region where the light reflecting resin is partially increased in this way, so that the entire protective element having a relatively high height can be obtained. Can be embedded with light reflecting resin.

  Of the light reflecting member, the surface (inner wall) facing the light emitting element is preferably an inclined surface that spreads upward as shown in the partial sectional view of FIG. 4B, for example. In FIG. 1B, both the inner wall and the outer wall are inclined surfaces, but only one of them (for example, the inner wall) may be inclined. Further, in FIG. 1B, the shape is rounded with no corners from the inner wall to the outer wall. However, the shape is not limited to this, and may be a shape such as a flat upper surface.

  Further, the distance between the inner shape and the outer shape of the light reflecting resin, that is, the width of the light reflecting resin in a top view can be adjusted in consideration of various factors such as the size of the substrate and the size of the light emitting element to be placed. Further, it is preferable to select in consideration of the balance with the height.

  The inner shape of the light reflecting resin disposed around the light emitting element will be described with reference to FIGS. 1C and 8. FIGS. 1C and 8 are top views of the light emitting devices 100 and 800. Conductor wirings 103A and 803A are provided on substantially rectangular substrates 101 and 801, respectively, and light emitting elements 1040 and 804 are placed thereon. ing. The light emitting element and the conductor wiring are connected by the conductive wires 105 and 805, but the conductive wire in the vicinity of the connecting portion is not shown because it is buried by the light reflecting resins 102 and 802. The inner shape of the light reflecting resin disposed around the light emitting element can be substantially rectangular as shown in FIG. 1C when viewed from above. However, the present invention is not limited to this, and a substantially rectangular corner may be rounded as shown in FIG. In particular, when the resin is formed by applying a highly viscous resin as the light reflecting resin, the light reflecting resin formed in the vertical direction and the horizontal direction are mixed and integrated so as to contact each other before being cured. In this case, the shape becomes round as shown in FIG. By adopting such a shape, it is possible to easily reflect light uniformly. In addition, the shape is not limited to the above shape, and may be a shape corresponding to desired light emission characteristics such as a circle, an ellipse, and a polygon when viewed from above.

  Further, in the present invention, the light reflecting resin may be formed so as to reach the side surface of the light emitting element. In that case, the inner shape is a shape corresponding to the shape of the light emitting element and its arrangement.

  In the light emitting device shown in FIG. 1C and the like, the light reflecting resin is formed so as to surround all of the plurality of light emitting elements. However, the light emitting device is not limited to this. A light reflecting resin may be provided around the individual. In this way, by arranging the light reflecting resin at a closer position and burying the conductive wire that absorbs light or the substrate that transmits / absorbs light, the loss of light can be efficiently reduced. Can do.

  The outer shape of the light reflecting resin disposed around the light emitting element will be described with reference to FIGS. 1C and 7 are top views of the light emitting devices 100 and 700. Conductor wirings 103A and 703A are provided on substantially rectangular substrates 101 and 701, respectively, and light emitting elements 1040 and 704 are placed thereon. ing. The light emitting element and the conductor wiring are connected by the conductive wires 105 and 705, but the conductive wire in the vicinity of the connecting portion is not shown because it is buried by the light reflecting resins 102 and 702. The outer shape of the light reflecting resin disposed around the light emitting element can be provided so that the outer edge of the light reflecting resin 702 is separated from the outer edge of the substrate 701 in a top view as shown in FIG. In this case, it is preferable that the outer edge shape of the substrate and the outer edge shape of the light reflecting resin are similar to each other. In the case of a substantially square substrate 701 as shown in FIG. It is preferable to use a substantially rectangular shape so that each side is substantially parallel.

  In this way, by separating the outer edge of the substrate from the outer edge of the light reflecting resin, in other words, by making the outer edge of the light reflecting resin smaller than the outer edge of the substrate, the dividing step is facilitated in the subsequent process. In particular, when a resin having a hardness different from that of a substrate is used as a light reflecting resin, for example, when a light reflecting resin having a lower hardness and malleability is provided on a ceramic substrate, a subsequent dividing step ( In some cases, the separation step is difficult to perform (hard to cut). Therefore, the outer edge of the substrate (that is, the dividing position) can be divided with high productivity by using only the substrate.

  Here, the dividing step will be described. 9A and 9B are diagrams showing a part of the assembly of the light emitting device before the substrate is divided. FIG. 9A is a diagram before the light reflecting resin molding, and FIG. 9B is a diagram after the light reflecting resin 902 is formed. . As shown in FIG. 9A, conductor wirings 903A and 903B are provided on a substrate 901, a light emitting element 904 is placed thereon, and the light emitting element and the conductor wiring are electrically connected using a conductive wire 905. Thereafter, as shown in FIG. 9B, a light reflecting resin 902 is provided around the light emitting element 904. Here, the light reflecting resin 902 is provided so as to intersect vertically and horizontally, and an arrow portion in the figure is a division position. By doing in this way, while forming light reflection resin easily, a division | segmentation process can be performed comparatively easily. However, other methods such as printing and coating may be used regardless of the shape and method.

  Moreover, it can also be set as the shape where the external shape (outer edge) of light reflection resin corresponds with a board | substrate.

  Furthermore, the outer edge of the substrate and the outer edge (outer shape) of the light reflecting resin can be made different. For example, as shown in FIG. 1A and the like, the light reflecting resin 102 is provided with a first region A that is separated from the outer edge of the substrate 101 and a second region B that is in contact with (matches) the outer edge of the substrate. it can.

  Only a part of the light reflecting resin is provided so as to be separated from the outer edge of the substrate, in other words, by exposing a part of the substrate, a part of the dividing (cutting) position can be only the substrate, and productivity It can be divided (cut) well. In this way, when cutting the light reflecting resin at a part of the dividing position, the productivity of the light reflecting resin and the substrate should be increased although the productivity is slightly inferior to the case of dividing only the substrate. Furthermore, there are merits such as simplification of the process of forming the light reflecting resin. Moreover, as shown in FIG. 8, it can be set as the shape where the cross | intersection part of the light reflection resin provided in the vertical direction and a horizontal direction was rounded.

  Further, the first region of the light reflecting resin is preferably formed so as to be sandwiched between the second regions on one side of the substrate. By doing in this way, the contact | adherence area of light reflection resin and a board | substrate can be enlarged. Moreover, when providing a lens member on light reflection resin, adhesiveness with the lens member can also be improved.

  Furthermore, it is preferable to provide the second region of the light reflecting resin so as to be separated from the corner of the substrate. By doing in this way, it can suppress that light reflection resin peels from a board | substrate. Further, by providing a mark or the like for determining the dividing position at the corner of the substrate so that it is not covered with the light reflecting resin, the dividing position accuracy can be improved.

  As a specific material constituting the light reflecting resin, a member that hardly absorbs light from the light emitting element and efficiently reflects is preferable. The specific reflectance is preferably at least 50% or more, more preferably 70% or more. In addition, when the light reflecting resin has the property of scattering light, it may be difficult to measure the reflectance, but as a reference value by a method such as obtaining the ratio with a standard diffusion plate using an integrating sphere. Can be measured.

Further, an insulating member is preferable, and a member that is not easily deteriorated by light from the light emitting element or external light is preferable. Moreover, it has a certain amount of strength, and a thermosetting resin, a thermoplastic resin, or the like can be used, and more specifically, a phenol resin, a glass epoxy resin, a BT resin, a PPA, a silicone resin, or the like can be given. By adding a reflecting member (for example, TiO ₂ , Al ₂ O ₃ , ZrO ₂ , or MgO) that reflects light from the light emitting element to the base resin, light can be efficiently reflected.

  Such a light reflecting resin is easily provided by ejecting a resin having a high viscosity from a nozzle tip corresponding to a desired size (width) after placing a light emitting element or a protective element to be described later on a conductor wiring. be able to. Moreover, it can also provide by methods, such as printing application | coating. The light reflecting resin thus provided can function as a protective member that protects the light emitting element and the like by being cured by heat or light.

(substrate)
The substrate is an insulating member on which conductor wiring is arranged, and is a substantially plate-like member to which a light reflecting resin can be provided. Examples of the material for the substrate include glass epoxy resin, ceramics, and glass. In particular, as the ceramic, alumina, aluminum nitride, mullite, silicon carbide, silicon nitride, or the like is preferable. By using these as materials, a substrate having high heat resistance can be obtained.

(Conductor wiring)
The conductor wiring is formed on the upper surface of the substrate, is provided so as to continue to the back surface through the inside or the front surface of the substrate, and has a function of making electrical connection with the outside. The size and shape of the conductor wiring can be variously selected. For example, like the light emitting device 100 shown in FIG. 1, the conductor wiring can be formed large so that the end portion is embedded in the light reflecting resin 102, or FIG. Like the light emitting device 200 shown in FIG. 5, the conductor wiring 203A having a portion separated from the light reflecting resin 202 may be provided, and the light emitting device 204 may be provided thereon. Moreover, the thing which has no electrical connection with the outside and functions as a light reflecting material is also included. Specific examples include metals such as copper, aluminum, gold, silver, tungsten, iron, nickel, iron-nickel alloys, phosphor bronze, iron-containing copper, and the like.

(Sealing member / lens member)
The sealing member is provided on or outside the region surrounded by the light reflecting resin, and is a member that protects the light emitting element, the protection element, and the like from dust, moisture, external force, and the like. Further, it is preferable to have a light-transmitting property capable of transmitting light from the light-emitting element and to have a light resistance that is not easily deteriorated by them. Specific examples of the material include silicone resin, epoxy resin, and urea resin. In addition to such materials, a colorant, a light diffusing agent, a filler, a color conversion member (fluorescent member), and the like can be included as desired.

  The filling amount of the sealing member may be an amount that covers a light emitting element, a protective element such as a Zener diode, a conductive wire, or the like.

  Further, the shape of the surface of the sealing member can be variously selected according to the light distribution characteristics and the like. For example, as shown in FIG. 4B, it can be filled so as to have a height equal to or lower than that of the light reflecting resin 402. Here, the concave portion is formed such that the vicinity of the center is slightly lower than the peripheral portion. However, the shape is not limited to this, and the surface may be flat or may be convex so that the vicinity of the center is higher than the peripheral portion. .

  In addition to the sealing member, a lens member may be provided. For example, as in the light-emitting device 600 shown in FIG. 6, a lens member having a hemispherical shape can be provided while reaching the outer edge of the substrate 601. Here, the lens member 608 is provided so as to be spherical from the upper part of the light reflecting resin 602 slightly outside.

  The outside of the light reflecting resin 602 does not need to have a lens shape because light from the light emitting element 604 does not easily reach. With such a shape, when the lens member is divided (divided) after being formed, the lens portion (spherical portion) can be divided without damaging it, which has an effect on the optical characteristics. Can be suppressed. In addition, by providing the lens member 608 as a separate member from the sealing member 606 as described above, for example, when using a wavelength conversion member (fluorescent member) as described later, the fluorescent member is mixed only in the sealing member 606. Thus, it is easy to define the amount of the fluorescent member for obtaining a desired emission color, and the lens portion can be made of only resin, so that it becomes easy to adjust the light distribution characteristics. The curvature and size of the lens can be variously selected so as to obtain desired light distribution characteristics.

  Further, the lens member can be not only a convex hemispherical lens as shown in FIG. 6 but also a shape in which a concave portion is provided to reflect light in the lateral direction, or a Fresnel lens shape. Further, depending on the purpose and application, a diffusing material, a pigment, a wavelength conversion member, or the like may be mixed.

(Die bond resin)
The die bond resin is a bonding member for mounting a light emitting element, a protective element, etc. on a substrate or a conductor wiring, and either a conductive die bond member or an edge die bond member is selected depending on the substrate of the element to be mounted. Can do. For example, in the case of a semiconductor light emitting device in which a nitride semiconductor layer is laminated on sapphire, which is an insulating substrate, the die bond member can be used either insulative or conductive, and when using a conductive substrate such as a SiC substrate, Conductivity can be achieved by using a conductive die bond member. As the insulating die bond member, an epoxy resin, a silicone resin, or the like can be used. In the case of using these resins, a metal layer having a high reflectance such as an Al film can be provided on the back surface of the semiconductor light emitting element in consideration of deterioration due to light or heat from the semiconductor light emitting element. In this case, a method such as vapor deposition, sputtering, or bonding a thin film can be used. In addition, as the conductive die bond member, a conductive paste such as silver, gold, or palladium, solder such as Au—Sn eutectic, or a brazing material such as a low melting point metal can be used. Further, among these die bond members, in particular, when a translucent die bond member is used, a fluorescent member that absorbs light from the semiconductor light emitting element and emits light of a different wavelength can be included therein.

(Conductive wire)
Examples of the conductive wire that connects the electrode of the light emitting element and the conductive member provided on the substrate include conductive wires using metals such as gold, copper, platinum, and aluminum, and alloys thereof. In particular, it is preferable to use gold excellent in thermal resistance.

(Wavelength conversion member)
In the translucent member, a fluorescent member that emits light having a different wavelength by absorbing at least a part of light from the semiconductor light emitting element may be included as a wavelength conversion member.

  As the fluorescent member, it is more efficient to convert the light from the semiconductor light emitting element into a longer wavelength. The fluorescent member may be formed of a single type of fluorescent material or the like, or may be formed of a single layer in which two or more types of fluorescent material are mixed, or contains one type of fluorescent material, etc. Two or more single layers may be stacked, or two or more single layers each of which is mixed with two or more kinds of fluorescent substances may be stacked.

Any fluorescent member may be used as long as it absorbs light from a semiconductor light emitting device having a nitride semiconductor as a light emitting layer and converts the light to light of a different wavelength. For example, nitride phosphors / oxynitride phosphors mainly activated by lanthanoid elements such as Eu and Ce, lanthanoid phosphors such as Eu, and alkalis mainly activated by transition metal elements such as Mn Earth halogen apatite phosphor, alkaline earth metal borate halogen phosphor, alkaline earth metal aluminate phosphor, alkaline earth silicate, alkaline earth sulfide, alkaline earth thiogallate, alkaline earth silicon nitride At least selected from organic and organic complexes mainly activated by lanthanoid elements such as germanate or lanthanoid elements such as Ce, rare earth aluminate, rare earth silicate or Eu Any one or more are preferable. Preferably, Y ₃ Al ₅ O ₁₂ : Ce, (Y _0.8 Gd _0.2 ) ₃ Al ₅ O ₁₂ : Ce, which is a rare earth aluminate phosphor mainly activated by a lanthanoid element such as Ce. Y ₃ (Al _0.8 Ga _0.2 ) ₅ O ₁₂ : Ce, (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ is a YAG phosphor represented by a composition formula. Further, there are Tb ₃ Al ₅ O ₁₂ : Ce, Lu ₃ Al ₅ O ₁₂ : Ce, etc. in which a part or all of Y is substituted with Tb, Lu, or the like. Furthermore, phosphors other than the above phosphors and having the same performance, function, and effect can be used.

(Semiconductor light emitting device)
In the present invention, it is preferable to use a light emitting diode as the semiconductor light emitting element.

A semiconductor light emitting device having an arbitrary wavelength can be selected. For example, as blue and green light emitting elements, those using ZnSe or a nitride semiconductor (In _X Al _Y Ga _1- XYN, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) are used. it can. As the red light emitting element, GaAs, InP, or the like can be used. Furthermore, a semiconductor light emitting element made of a material other than this can also be used. The composition, emission color, size, number, and the like of the light emitting element to be used can be appropriately selected according to the purpose.

In the case of a light-emitting device having a fluorescent material, a nitride semiconductor (In _X Al _Y Ga _1- XYN, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) is preferable. Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal.

  Further, a light-emitting element that outputs not only light in the visible light region but also ultraviolet rays and infrared rays can be obtained. Furthermore, a light receiving element or the like can be mounted together with the semiconductor light emitting element.

<Example 1>
As shown in FIG. 9A, a substrate is prepared on a plate-like alumina ceramic provided with conductor wiring with Ag plating on the surface. On the conductor wiring, six light emitting elements made of a nitride semiconductor having sides of 500 μm and 290 μm are bonded using a eutectic bonding member made of AuSn. Here, the light-emitting elements used have blue light emission with a dominant wavelength of about 450 nm, and all six have substantially the same wavelength.

Next, a white resin (light reflecting resin) in which 50 wt% of titania (TiO ₂ ) having an average particle diameter of 0.25 μm is dispersed in a silicone resin is placed around the six light emitting elements using a dispenser. Draw (apply).

  In this way, an assembly of light emitting elements formed with the light reflecting resin as shown in FIG. 9B is manufactured. At this time, the line width of each light reflecting resin (the portion where the vertical and horizontal light reflecting resins do not intersect) is 600 μm at the width of the lower portion of the light reflecting resin that is in contact with the substrate (maximum width in top view). Covers the exposed portion (exposed region) of the alumina ceramic substrate between the conductor wiring on which the metal wire is placed and the conductor wiring to which the gold wire is directly connected, and the exposed region of the substrate between the light emitting element and the light reflecting resin Try not to have it. At this time, a part of the conductive wire is formed so as to be embedded in the light reflecting resin.

  After heat-curing the light-reflecting resin, a YAG phosphor having an average particle diameter of 6 μm was dispersed in a weight ratio of 50 wt% in a silicone resin different from the above to form a sealing member, which was surrounded by a white-based light-reflecting resin. It seals by dripping (potting) on a light emitting element.

  After the sealing member is cured, the surface side of the sealing member is further covered with a silicone resin having a lens shape, and thereafter, the arrow portion in FIG. 9B is divided by dicing, and the size of the substrate is □ 3.5 mm. Thus, the light emitting device of the present invention is obtained.

  As a comparison, the results of measuring the electro-optical characteristics of a light-emitting device produced by using a transparent resin in which titania is not dispersed as a substitute for the light-reflecting resin in Example 1 are shown below.

<Table 1>

  As described above, in Example 1, since the exposed portion of the conductive wire and the substrate was embedded by the light reflecting resin, the luminous flux was about 8% higher than that of the comparative example using the transparent resin.

<Example 2>
In Example 1, as shown in FIG. 9A, after the light emitting element 904 is placed on the conductor wiring 903A, a protective element made of Si (silicon) having a side of 240 μm square is placed on the conductor wiring 903B with Ag paste. Then, except that a light reflecting resin 902 as shown in FIG. 9B is provided so that this protective element is embedded, the light emitting element of the present invention is obtained in the same manner as in Example 1. In the second embodiment, the conductor wiring 903B is formed slightly longer (larger) in order to place the protection element.

<Example 3>
A light emitting element made of a nitride semiconductor having a 1 mm square on each side is bonded with AuSn eutectic using a substrate on which a Au-based conductor wiring is applied on a black aluminum nitride plate. At this time, the electrodes of the light emitting elements are arranged so as to face the conductor wiring side, and are joined without using a conductive wire. The light emitting element used here has a blue emission wavelength as in the first embodiment.

  Next, 240 μm square protective elements are bonded onto the conductor wiring with Ag paste, and electrical connection is made to the conductor wiring of each pole with a conductive wire made of gold.

  Next, a white resin (light-reflecting resin) in which 20 wt% of titania having an average particle diameter of 0.25 μm is dispersed in a low-viscosity silicone resin is formed (drawn) around the light-emitting element using a dispenser.

  At this time, the light reflecting resin is formed on all the substrates and the conductor wiring except the mounting surface of the light emitting element. Therefore, only the upper surface of the light emitting element is exposed.

  In this way, light emitted from the light emitting element can be extracted from the upper surface without entering the black substrate.

  In the light emitting device according to the present invention, since the light reflecting resin surrounding the light emitting element is provided so as to embed a part of the conductive wire, the light emitting device can reduce the light absorption and increase the output. It can also be used for various display devices, lighting fixtures, displays, backlight light sources for liquid crystal displays, and also for image reading devices, projector devices, etc. in facsimiles, copiers, scanners, and the like.

FIG. 1A is a perspective view showing an example of a light emitting device according to the present invention. 1B is a partial cross-sectional perspective view of the light-emitting device according to FIG. 1A taken along the line X-X ′. FIG. 1C is a top view of the light emitting device according to FIG. 1A. FIG. 2 is a perspective view showing an example of a light emitting device according to the present invention. FIG. 3 is a partial cross-sectional perspective view showing an example of the light emitting device according to the present invention. FIG. 4A is a perspective view showing an example of a light emitting device according to the present invention. 4B is a cross-sectional view taken along the line Y-Y ′ of the light-emitting device according to FIG. 4A. 4C is a cross-sectional view taken along the line Z-Z ′ of the light emitting device according to FIG. 4A. FIG. 5 is a perspective view showing another example of the light-emitting device according to FIG. 4A in the Z-Z ′ section. FIG. 6 is a cross-sectional view showing an example of a light emitting device according to the present invention. FIG. 7 is a top view showing an example of the light emitting device according to the present invention. FIG. 8 is a top view showing an example of the light emitting device according to the present invention. FIG. 9A is a diagram illustrating a part of the aggregate of the light emitting device before dividing the substrate, and is a diagram illustrating a state before the light reflecting resin molding. FIG. 9B is a diagram illustrating a part of the aggregate of the light emitting devices before the substrate is divided, and is a diagram illustrating a state after the light reflecting resin is formed in addition to FIG. 9A.

Explanation of symbols

100, 200, 300, 400, 500, 600, 700, 800 ... light emitting devices 101, 201, 301, 401, 501, 601, 701, 801, 901 ... substrates 102, 202, 302, 402, 502 , 502A, 502B, 602, ... Light reflecting resin 103A, 103B, 203A, 303A, 303B, 403A, 403B, 703A, 803A, 903A, 903B ... Conductor wiring 104, 204, 304, 404, 604, 704 , 804, 904... Light emitting elements 105, 205, 305, 405, 705, 805, 905... Conductive wires 406, 606... Sealing member 307. ..Part of light emitting device assembly

Claims (9)

A substrate on which conductor wiring is arranged;
A light emitting device placed on the conductor wiring;
A light reflecting resin disposed around the light emitting element and reflecting light from the light emitting element;
A conductive wire for conducting the conductor wiring and the light emitting element;
Have
At least a part of the conductive wire is embedded in the light reflecting resin. A substrate on which conductor wiring is arranged;
A light emitting device placed on the conductor wiring;
A light reflecting resin that is disposed around the light emitting element and reflects light from the light emitting element;
The substrate has an exposed region exposed from the conductor wiring;
At least a part of the exposed region is embedded in the light reflecting resin. A substrate on which conductor wiring is arranged;
A light emitting device placed on the conductor wiring;
A protective element placed on the conductor wiring;
A light-reflecting resin that is disposed around the light-emitting element and reflects light from the light-emitting element, wherein at least a part of the protective element is embedded in the light-reflecting resin. Light emitting device.   The light emitting device according to claim 1, wherein the substrate has an exposed region exposed from the conductor wiring, and at least a part of the exposed region is embedded in the light reflecting resin.   The light-emitting device according to claim 1, further comprising a protective element that is electrically connected to the conductor wiring, wherein at least a part of the protective element is embedded in the light reflecting resin.   The light-emitting device according to claim 1, wherein the light reflecting resin includes a first region that is separated from an outer edge of the substrate and a second region that is in contact with the outer edge of the substrate.   The light emitting device according to claim 6, wherein the first region is sandwiched between the second regions on one side of the substrate.   The light emitting device according to claim 6, wherein the second region is separated from a corner of the substrate.   The light emitting device according to claim 1, wherein at least a part of the light emitting element is in contact with the light reflecting resin.

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