JP4241870B2 - Light emitting device and manufacturing method thereof - Google Patents

Abstract

A light emitting device and manufacturing method thereof, wherein the light emitting device 100 includes a light emitting element 101, a package for arranging the light emitting element 101, and an electrically conductive wire 106 for connecting an electrode disposed on the package and an electrode of the light emitting element. The package includes a support member 108 having a mounting portion to arrange the light emitting element 101 and defining a recess 103 to house a semiconductor element 102 which is different than the light emitting element, and a light transmissive member 107 covering at least the light emitting element 101. The package defines a hollow portion 111 between the light transmissive member 107 covering the opening of the recess 103 and an inner wall defining the recess 103.

Description

The present invention relates to a light emitting device used for a lighting fixture, a display, a backlight of a mobile phone, a moving image illumination auxiliary light source, other light sources, and the like, and a method for manufacturing the same.

  A light-emitting device using a light-emitting element such as a light-emitting diode is small in size, power-efficient, and emits bright colors. In addition, unlike a light bulb or the like, such a light emitting element does not have to worry about a broken bulb. Furthermore, it has the characteristics that it has excellent initial drive characteristics and is resistant to repeated vibration and on / off lighting. Because of such excellent characteristics, light-emitting devices using light-emitting elements such as light-emitting diodes (LEDs) and laser diodes (LDs) are used as light sources for lighting fixtures and backlights of mobile phones.

  In such a light-emitting device, a protective element such as a Zener diode may be mounted on the light-emitting device in order to protect the light-emitting element from destruction due to overvoltage. Such a protective element is disposed adjacent to the light emitting element on the support substrate on which the light emitting element is mounted, and is electrically connected to the light emitting element.

  For example, a light emitting device disclosed in Patent Document 1 below includes an insulating substrate provided with first and second electrodes having different polarities, an LED chip disposed on the upper surface side of the first electrode, The protective element (for example, Zener diode) arrange | positioned at the 2nd electrode and the sealing resin which coat | covers the LED chip and the electroconductive wire connected to this LED chip are provided. Furthermore, one electrode of the LED chip is connected to the first electrode, and the other electrode is connected to the second electrode by wires. On the other hand, the upper surface side electrode of the protective element is connected to the first electrode by a conductive wire, and the lower surface side electrode is connected to the second electrode via a conductive adhesive.

  In such a light-emitting device, the light extraction efficiency of the light-emitting device as a whole may be reduced when light from the light-emitting element is absorbed by the protective element or is blocked by the protective element. Therefore, if a concave portion is formed under the protective element so that the height of the protective element is lower than the height of the light emitting element, and the protective element is disposed in the concave portion, light blocking by the protective element may be reduced. it can. Alternatively, as in the light-emitting device disclosed in Patent Document 2 below, a reflective member different from the translucent member that covers the light-emitting element is disposed between the light-emitting element and the protective element, so that light from the light-emitting element is emitted. By reflecting outside the light emitting device, the protective element does not interfere with the path of light extracted from the light emitting element to the outside of the light emitting device. In consideration of ease of work when mounting a plurality of semiconductor elements on a support substrate, the recess for storing the protective element has an opening on the same surface as the surface on which the light emitting element is mounted. It is preferable that it is provided on the support substrate.

Japanese Patent Application Laid-Open No. 11-54804.

JP2007-150229A.

  However, when the protective element is placed in the recess formed below the mounting surface of the light emitting element, part of the light emitted from the end face direction of the light emitting element placed above is confined in the recess. Thereby, the light extraction efficiency to the outside of the light emitting device is reduced. Further, when the body color of the protective element absorbs light from the light emitting element, the light confined by the protective element is absorbed by the protective element, so that the output of the light emitting device is significantly reduced. Further, it is not practical to attempt to prevent the intrusion of light into the recess by embedding the recess for housing the protective element with a light-reflective filling, because it takes time and material costs.

  Accordingly, an object of the present invention is to provide a light emitting device having excellent reliability and optical characteristics, and to provide a method for manufacturing such a light emitting device at low cost.

In order to achieve the above object, a light emitting device according to the present invention includes a light emitting element, a package in which the light emitting element is disposed, an electrode provided in the package, and a conductive wire that connects the electrode of the light emitting element. And a support having a mounting portion in which the package arranges the light emitting element and a recess for housing a semiconductor element different from the light emitting element, and a translucent member disposed on the support, The translucent member covers at least the light emitting element and the opening of the recess, and includes a side surface of the semiconductor element housed in the recess and an inner wall surface of the recess. Between the two, a cavity is provided . The cavity further includes a bottom surface of the light transmissive member covering the opening, it is preferably provided between the upper surface of the semiconductor element housed in the recess.

  It is preferable that the translucent member has a protruding portion that is convex from the opening of the recess toward the bottom surface of the recess.

  The recess is provided in a region sandwiched between the plurality of mounting portions of the light emitting element, and the support preferably includes external connection electrodes substantially directly below the mounting portion.

  The similarity ratio between the outer shape of the opening of the recess in plan view and the outer shape of the semiconductor element accommodated in the recess in plan view is preferably 1.0 to 2.5.

  In order to achieve the above object, a method for manufacturing a light-emitting device according to the present invention includes a light-emitting element, a package in which the light-emitting element is disposed, an electrode provided in the package, and a conductive material that connects the electrode of the light-emitting element. A translucent member that covers at least the light emitting element, a mounting portion in which the light emitting element is disposed, and a recess that houses a semiconductor element different from the light emitting element. A light emitting device comprising: a support; and a first step of forming a support having a recess opening on an upper surface on which the light emitting element is mounted, and the upper surface of the semiconductor element emits light on the upper surface. A second step of disposing the semiconductor element in the recess, a third step of disposing the light emitting element and the conductive wire, and a lower step of the element mounting portion. While forming a sinus, and having a fourth step of the light-transmissive member covering at least the light emitting element and the opening of the recess is arranged in the support body.

  Preferably, the fourth step includes a step of continuously supplying the material of the translucent member in a direction substantially parallel to the mounting surface of the light emitting element.

  The viscosity of the material of the translucent member is preferably adjusted based on the size of the recess relative to the size of the semiconductor element so that bubbles remain in the recess in the fourth step. .

  The material of the translucent member preferably contains at least one resin selected from silicone resins or epoxy resins, and the resin contains a particulate phosphor.

  The viscosity of the material of the translucent member is preferably 200 Pa · s or more and 500 Pa · s or less.

  The similarity ratio between the outer shape of the opening of the recess in plan view and the outer shape of the semiconductor element housed in the recess in plan view is 1.0 to 2.5, and the depth of the recess and the recess The ratio of the height of the housed semiconductor element is preferably 1.0 to 2.14.

  In the light emitting device according to the present invention, the protection element is disposed on the bottom surface of the recess that is lower than the mounting surface of the light emitting element, and the cavity is further provided in the recess in which the protection element is accommodated. Here, a difference in refractive index is generated between the light-transmitting member that covers the light-emitting element and the cavity. Then, the light emitted from the light emitting element and the light from the phosphor are reflected at the boundary surfaces having different refractive indexes and extracted outside the light emitting device. That is, according to the present invention, the light extraction efficiency of the light emitting device can be improved by using the cavity provided in the recess as compared with the prior art. In addition, since the light is extracted from the light emitting device without being lost in the concave portion, the variation in the light distribution chromaticity of the light emitting device is reduced.

  In the light emitting device according to the present invention, a cavity formed by arranging the translucent member on the support is provided in the concave portion in which the protective element is accommodated, thereby preventing light from entering the concave portion. Therefore, in comparison with what embeds a light-reflective filling in the recess, or provides a reflective member different from the translucent member that covers the light-emitting element between the light-emitting element and the protective element, The present invention can provide an inexpensive light-emitting device with a relatively simple structure with less light loss due to the concave portion that houses the protective element.

  In addition, the method for manufacturing a light emitting device according to the present invention is compared to a method of embedding a light-reflective filler in a recess for housing a protective element or a method of providing a reflective member between a light emitting element and a protective element. A light emitting device with little light loss in the recess can be formed relatively easily and inexpensively. Furthermore, the method for manufacturing a light-emitting device according to the present invention includes a step of forming a light-transmitting member that covers the light-emitting element on a support, whereby bubbles remain in a recess having a bottom surface lower than the mounting surface of the light-emitting element. Can be done at the same time. Therefore, it is possible to manufacture a light emitting device with little light loss in the recesses relatively easily and inexpensively.

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

  Further, the present specification by no means specifies the members shown in the claims to the members of the embodiments. 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 description unless otherwise specified. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Further, in the following description, the same name and reference sign indicate the same or the same members, and detailed description 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.

  A light emitting element, a package in which the light emitting element is disposed, and a conductive wire that connects an electrode provided in the package and the electrode of the light emitting element, and the package further includes a mounting portion on which the light emitting element is disposed. In order to reduce the loss of light due to the recess, the light-emitting device includes a support having a recess that houses a semiconductor element different from the light-emitting element, and a translucent member that covers at least the light-emitting element. The inventor conducted various studies. As a result, the problem is solved by covering the opening of the recess that houses the semiconductor element different from the light emitting element with a part of the light-transmitting member that covers the light emitting element, and forming a cavity in the recess. It came to do. In the present invention, by having a cavity in the recess, a refractive index difference is generated between the light-transmitting member that covers the opening of the recess and the cavity. Then, light is reflected and emitted from the light emitting device with the boundary surfaces having different refractive indexes as reflection surfaces. As described above, according to the present invention, since light is not lost in the recess, the light extraction efficiency of the light emitting device is improved as compared with the prior art.

  Furthermore, the cavity in the package of the light emitting device is preferably provided between the bottom surface of the translucent member that covers the opening of the recess and the top surface of the semiconductor element housed in the recess. This is because light propagating through the translucent member can be prevented from being absorbed by the semiconductor element housed in the recess.

  It is preferable that the translucent member has a protrusion at the opening of the recess, and the protrusion has a convex bottom surface toward the bottom surface of the recess. This is because such a protrusion increases the effect of reflecting light toward the translucent member on the upper surface of the support without causing light to enter the recess. Moreover, it is preferable that a cavity is provided between the translucent member or the bottom surface of the protruding portion and the top surface of the semiconductor element housed in the recess. By providing a gap between the bottom surface of the translucent member and the upper surface of the semiconductor element, the light outside the recess does not reach the semiconductor element and is lost by the semiconductor element housed in the recess. Nothing will happen.

  The similarity ratio between the outer shape of the opening of the recess in plan view and the outer shape of the semiconductor element accommodated in the recess in plan view is preferably 1.0 to 2.5. This is because if the size of the opening of the recess is too large relative to the size of the semiconductor element, more light will enter the recess. In addition, if the size of the opening is too small with respect to the size of the semiconductor element, the workability of the process of arranging the semiconductor element in the recess is reduced, so that a light-emitting device with good mass productivity cannot be obtained. is there.

  A light-emitting element, a package in which the light-emitting element is disposed, and a conductive wire that connects an electrode provided in the package and the electrode of the light-emitting element, and the package at least covers the light-emitting element Regarding a method for manufacturing a light-emitting device including a member, a mounting portion in which the light-emitting element is disposed, and a support having a recess that houses a semiconductor element different from the light-emitting element, the present inventor Various studies were conducted to manufacture a light emitting device with a small amount of light relatively easily and inexpensively. As a result, the manufacturing method according to the present invention includes a first step of forming a recess having an opening on the mounting surface of the light emitting element on the support, and the upper surface of the semiconductor element is disposed below the mounting surface of the light emitting element. A second step of housing the semiconductor element in the recess, a third step of arranging the light emitting element and the conductive wire, and a transparent covering at least the light emitting element and the opening of the recess while forming a cavity in the recess. It has come to solve a subject by having the 4th process of arranging a photonic member on a support. That is, the method for manufacturing a light emitting device according to the present invention does not require a step of embedding a light-reflective filling in the concave portion that accommodates the semiconductor element, so that a light emitting device with little light loss in the concave portion is relatively simple and inexpensive. Can be manufactured.

  Moreover, this invention can simplify the process of manufacturing a light-emitting device by performing the formation of the translucent member to a support body, and formation of a cavity in the same process. According to such a method, the fourth step of forming the translucent member includes a step of continuously supplying the material of the translucent member in a direction substantially parallel to the mounting surface of the light emitting element. That is, a light-transmitting member material is poured in a direction substantially parallel to the mounting surface on which the light-emitting element is disposed, and the light-transmitting member is molded and cured with a mold to form a light-transmitting member. To do. Note that “substantially parallel” includes an allowable range of about ± 10 ° with respect to a plane parallel to the mounting surface of the light emitting element.

  The viscosity of the material of the translucent member is adjusted so that cavities are formed as remaining bubbles in the fourth step based on the size of the semiconductor element to be accommodated and the recess. For example, the size and depth of the recess have a similarity ratio of 1.0 to 2.5 between the outer shape of the recess opening in plan view and the outer shape of the semiconductor element housed in the recess in plan view. And it is preferable that ratio (D / H) of the depth D of a recessed part and the height H of the semiconductor element accommodated in the recessed part shall be 1.0 to 2.14. This is because the size of the bubbles is set to the minimum necessary so as not to reduce the reliability of the light emitting device.

  Furthermore, the viscosity of the material of the translucent member is preferably 200 Pa · s or more and 500 Pa · s or less. When the viscosity is low, the recess is filled with the material of the translucent member without forming a cavity in the recess containing the semiconductor element. On the other hand, if the viscosity is too high, the workability of the step of arranging the material of the translucent member is lowered.

  Further, by adjusting the viscosity of the material of the translucent member, the material is extended in a convex shape from the opening of the recess toward the bottom surface of the recess, and the protruding portion of the translucent member is formed in the opening of the recess. Form. And it can also be set as the light-emitting device which provided the cavity between the convex bottom face in the protrusion part of a translucent member, and the upper surface of the semiconductor element accommodated in the recessed part.

  The material of the translucent member preferably contains at least one resin selected from silicone resins or epoxy resins, and the resin contains a particulate phosphor. By adjusting the content of the particulate phosphor in the resin, the viscosity of the resin containing the particulate phosphor can be easily adjusted, and the light emitting device including the phosphor in the translucent member of the present invention This is because a cavity can be easily formed.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a top view schematically showing a light emitting device 100 of this embodiment. 2 is a cross-sectional view schematically showing a cross section in the XX direction of FIG. 1, and FIG. 3 is a cross-sectional view schematically showing a cross section in the YY direction of FIG. FIG. 4 is a bottom view schematically showing the light emitting device 100 of the present embodiment. FIG. 5 is a perspective view schematically showing the light emitting device 100 of the present embodiment. FIG. 6 is a cross-sectional view schematically showing the same cross section as the light-emitting device 100 shown in FIG. 2 for a light-emitting device 200 different from the light-emitting device of the present embodiment.

  As shown in FIG. 1, the light-emitting device 100 of the present embodiment includes two light-emitting elements 101a and 101b as main constituent members, a support 108 on which the light-emitting elements are arranged, and the same support as the light-emitting elements. Another mounted semiconductor element 102, a first conductive wire 105 connecting the electrode of the semiconductor element 102 to the electrode of the support, and a second conductive wire 106 connecting the electrode of the light emitting element to the electrode of the support And comprising.

  In this embodiment, the semiconductor element 102 mounted on the support separately from the light emitting element is a protective element (for example, a Zener diode) for protecting the light emitting element from overvoltage. The support 108 has a recess 103 that is recessed from the upper surface side where the light emitting elements 101 a and 101 b are arranged toward the bottom surface side, and the protection element is accommodated in the recess 103.

  Further, as shown in FIGS. 2, 3, and 5, a translucent member 107 is disposed on the upper surface of the support 108 so as to close the opening of the recess 103. The light emitting elements 101a and 101b arranged at least on the upper surface side and the second conductive wire 106 connected thereto are covered. Here, the recess 103 has a cavity between the translucent member disposed on the upper surface of the support 108 and the inner wall of the recess. Here, the “cavity” in the present invention is a bubble that is formed inside the light-transmitting member 107 or between the light-transmitting member 107 and the support and contains air or other gas. It may be a gap formed between the lower surface of the optical member 107 and the recess. Such a cavity is disposed outside the semiconductor element disposed in the recess, particularly in the direction in which light travels from the upper side of the semiconductor element, that is, from the outside of the opening. The shape and number of cavities are not limited. For example, a large number of spherical cavities may be dispersed in the recesses. By disperse | distributing and arrange | positioning a cavity, the effect similar to when a diffusing agent is contained in the translucent member is acquired. In other words, the light is diffused by the translucent member, thereby suppressing the intrusion of light toward the bottom surface of the recess. The position of the cavity is not limited between the bottom surface of the translucent member in the opening and the top surface of the semiconductor element. A cavity formed between the translucent member covering the opening of the recess and the inner wall of the recess may be used. For example, the cavity is formed between the side surface of the semiconductor element housed in the recess and the inner wall surface of the recess. It may be provided.

  As shown in FIGS. 2 and 3, the light emitting device 100 in this embodiment is provided between the lower surface of the translucent member 107 covering the opening of the recess 103, the upper surface of the semiconductor element 102, and the inner wall of the recess 103. A cavity 111 formed. Light incident on the boundary surface between the cavity 111 formed in the opening of the recess 103 and the translucent member 107 can be reflected toward the translucent member 107. Therefore, the light-emitting device 100 of this embodiment can extract light to the outside of the light-emitting device without allowing light to enter the recess 103.

  Such a cavity 111 can be integrally formed in the step of forming the translucent member 107 on the support 108. For example, after a stencil or a mask is arranged on the upper surface of the support 108, the material of the translucent member 107 can be printed. This method is a method of covering each member arranged on the upper surface of the support 108 by arranging the material while supplying the material continuously in a direction substantially parallel to the upper surface of the support. Therefore, it is necessary to dispose the material of the translucent member 107 while forming the cavity 111 in the recess 103 without completely filling the recess 103 with the material of the translucent member 107. The material of the translucent member 107 of this embodiment is adjusted to a predetermined viscosity in advance in consideration of the size of the opening of the recess 103 and the ease of work in the step of arranging the material. For example, in order to obtain a light-emitting device that contains a phosphor in a translucent member, the phosphor is a YAG-based phosphor, and the translucent member is a silicone resin. The viscosity of the material thus prepared is adjusted to 200 Pa · s or more and 500 Pa · s or less by measurement with a B-type viscometer.

  Note that the manufacturing method of the present embodiment utilizes the fact that when the material of the translucent member is disposed on the upper surface of the support, a cavity due to remaining bubbles is easily formed in the recess recessed from the upper surface of the support on which the light emitting element is mounted. is doing. In other words, the protective element is accommodated in the recessed portion, and a cavity is formed by leaving bubbles around the protective element. Therefore, according to the method for manufacturing a light-emitting device in this embodiment, a material for a light-transmitting member that covers the light-emitting element is disposed on the upper surface of the support, and a cavity is left in a recess having a bottom surface lower than the mounting surface of the light-emitting element Can be combined with the step of forming. In the light-emitting device of this embodiment, a light-emitting device with high light extraction efficiency can be manufactured relatively easily and inexpensively as compared with a case where a light-reflective filling is embedded in a recess that houses a protective element.

  Further, in the light emitting device of this embodiment, as illustrated in FIG. 6, the protruding portion 112 of the translucent member 107 can be provided in the opening portion of the recessed portion 103. The projecting portion 112 is a portion of the translucent member 107 having a convex surface protruding in a convex shape toward the bottom surface of the concave portion. Furthermore, a cavity 111 can be provided between the convex bottom surface of the protrusion 112 and the upper surface of the semiconductor element 102 housed in the recess. Such a projecting portion 112 of the translucent member can be formed by adjusting the shape by using the fluidity of the translucent member having a certain degree of viscosity and then curing it. That is, after adjusting the viscosity of the material of the translucent member, the fluid material is extended in a convex shape from the opening of the concave portion toward the bottom surface of the concave portion, and is cured when the desired shape is obtained. In addition, the degree of extension of the recess in the bottom surface direction can be adjusted by appropriately adjusting the viscosity of the material of the translucent member. Thereby, a cavity can be formed between the convex bottom surface of the protruding portion and the upper surface of the semiconductor element housed in the concave portion, or the size thereof can be adjusted.

  Alternatively, the cavity 111 in this embodiment is a concave portion in which the translucent member 107 formed in advance in another process is disposed on the upper surface of the support 108 and a semiconductor element is disposed in a part of the translucent member 107. It can also be provided by closing the opening. That is, of the translucent member 107 disposed on the upper surface of the support 108 so as to cover the light emitting element, a cavity is formed between the lower surface of the translucent member 107 that closes the opening of the recess 103 and the recess 103. The light can also be reflected outside by the lower surface of the translucent member and taken out to the outside. In consideration of improvement in productivity, as described above, it is preferable to use a manufacturing method in which a cavity is formed at the same time as the formation of a light-transmitting member covering a light-emitting element or a conductive wire.

  In the present specification, the upper surface of each member refers to the surface on the side on which the light emitting element is mounted among the surfaces forming the external shape of the support, and the surface facing the upper surface is the bottom surface. Moreover, let the surface between them which connects an upper surface and a bottom face be a side surface.

  The light-emitting device 100 of this embodiment includes a pair of positive and negative external connection electrodes 110a and 110c. When the light-emitting device 100 is soldered to a wiring board (not shown), the external connection electrodes 110a and 110a are connected via the solder. 110c is connected to the electrode of the wiring board. At this time, the external connection electrodes 110a and 110c can be a heat dissipation path from the support body to the wiring board via the solder.

  Therefore, if the mounting portion of the light emitting element is disposed almost directly above the external connection electrode provided on the bottom surface side of the support, the heat dissipation path can be shortened, so that the heat dissipation of the light emitting device is improved. Further, when the mounting portion of the plurality of light emitting elements 101a and 101b is provided on the support body 108 as in the light emitting device 100 of the present embodiment, the support body has a plurality of light emitting elements respectively arranged when viewed from the top surface direction. It is preferable to provide a support having an opening portion of a recess for housing a semiconductor element different from the light emitting element in a region sandwiched between the mounting portions 104b. Furthermore, it is preferable that a pair of positive and negative external connection electrodes 110a and 110c of the light emitting device 100 are extended to directly below the mounting portions 104b of the light emitting elements 101a and 101b. That is, the outer shape of the external connection electrodes 110a and 110c arranged on the back surface of the support 108 constituting the light emitting device 100 is the same as the arrangement pattern outer shape of the mounting portion 104b from the upper surface of the support 108 (shown in FIG. 1). When projected vertically toward the back surface (shown in FIG. 4), it is preferably a shape including at least a part of the projected shape, and more preferably a shape including all of the projected shape.

  For example, in the light emitting device of this embodiment, as shown in FIG. 4, a pair of positive and negative external connection electrodes 110 a and 110 c arranged on the bottom surface of the support are mounted on the light emitting elements 101 a and 101 b from both ends of the support 108. It extends just below the portion 104b. Due to the arrangement relationship between the external connection electrode and the mounting portion of the light emitting element, when a plurality of light emitting elements are mounted on the support, the concave portion or the cavity provided in the concave portion is connected to the external connecting electrode from the mounting portion of the light emitting element. There is no hindrance to heat dissipation via the circuit board. Therefore, the heat dissipation of the light emitting device is not lowered, and the output of the light emitting device can be improved.

  It is also possible to provide a pair of positive and negative electrodes in the recess in which the semiconductor element is accommodated, and to make electrical connection between the electrode and the semiconductor element in the recess. The electrode connection method between the electrode in the recess and the semiconductor element is, for example, a pair of positive and negative electrodes exposed on the bottom surface of the recess and the electrode of the semiconductor element facing each other by a bump or the like. The electrode can be connected to the electrode on the bottom surface of the recess with a conductive wire. The conductive wire connected to each electrode of the semiconductor element and the electrode in the recess is preferably housed entirely in the recess. That is, it is preferable that the topmost part of the conductive wire is below the upper surface of the support body on which the light emitting element is disposed. As a result, the translucent member 107 is less likely to affect the conductive wire, and the reliability of the light emitting device due to metal fatigue of the conductive wire can be eliminated.

  In a structure having a concave portion between a light emitting element and another light emitting element as in the light emitting device of this embodiment, the amount of light increases in a region sandwiched between the light emitting elements, and they are in the concave portion. If it enters, the loss of light increases. In order to reduce the light loss in the light emitting device having such a configuration, the present invention can be particularly preferably applied. Hereinafter, each component in the light emitting device of the present embodiment will be described in detail.

(Light emitting element)
In this embodiment, a semiconductor device in which a light emitting element and a protection element are arranged on a support will be described. However, the present invention is not limited to such a form, and a light receiving element, other protection elements (such as a resistor, a transistor, or a capacitor), Or it can be set as the semiconductor device carrying what combined those at least 2 or more types. There may be one or more light emitting elements, protective elements or other semiconductor elements housed in the recesses. The light emission color of the light emitting element may be any one of red, green, and blue, or a combination thereof.

When the light-emitting element in this embodiment is a light-emitting device including a fluorescent substance, a semiconductor light-emitting element having an active layer that can emit light having a wavelength capable of exciting the fluorescent substance is preferable. Examples of such semiconductor light emitting devices include various semiconductors such as ZnSe and GaN, but nitride semiconductors (In _X Al _Y Ga _1- XYN capable of emitting short wavelengths capable of efficiently exciting fluorescent materials). , 0 ≦ X, 0 ≦ Y, X + Y ≦ 1). Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal.

  When a nitride semiconductor is used as the material of the light emitting element, a material such as sapphire, spinel, SiC, Si, ZnO, or GaN is preferably used for a semiconductor substrate for stacking semiconductors. In order to form a nitride semiconductor with good crystallinity with high productivity, it is preferable to use a sapphire substrate. A nitride semiconductor can be formed on the sapphire substrate by MOCVD or the like. Further, the semiconductor substrate can be removed after the semiconductor layer is laminated.

  In the case of a light emitting device that emits white mixed color light, the emission wavelength of the light emitting element is preferably 400 nm or more and 530 nm or less in consideration of the complementary color relationship with the emission wavelength from the fluorescent material and the deterioration of the sealing resin, and 420 nm. More preferably, it is 490 nm or less. In order to further improve the excitation and emission efficiency of the light emitting element and the fluorescent material, 450 nm or more and 475 nm or less are more preferable.

  It is preferable to select a gallium / aluminum / arsenic semiconductor or an aluminum / indium / gallium / phosphorous semiconductor as a material of a light emitting element that emits red light.

  In order to obtain a full-color display device, it is preferable to combine light emitting elements having a red light emission wavelength of 610 nm to 700 nm, a green light emission wavelength of 495 nm to 565 nm, and a blue light emission wavelength of 430 nm to 490 nm.

  After fixing the light emitting element to the support, each electrode of the light emitting element and the conductor wiring of the support are connected by a conductive wire. Here, the joining member for fixing the light emitting element is not particularly limited, and is an insulating adhesive such as an epoxy resin, a eutectic material containing Au and Sn, a brazing material such as a low melting point metal, and conductivity. A conductive paste or glass made of a resin containing the material can be used. Here, the conductive material contained in the conductive paste is preferably Au, Sn, or Ag. More preferably, the Ag paste having an Ag content of 80% to 90% is used. A device is obtained. Note that a semiconductor element having an electrode on the bottom surface side can be bonded to a support with a conductive paste containing a metal material such as silver, gold, or palladium.

  In the case of a light emitting element formed by laminating a nitride semiconductor on a translucent sapphire substrate, examples of the bonding member include an epoxy resin and silicone. At this time, a metal material such as silver or aluminum may be disposed on the bottom surface of the light-emitting element (that is, the surface opposite to the surface on which the nitride semiconductor is stacked in the sapphire substrate, hereinafter the same in this paragraph). . For example, a metal layer can be formed by evaporating or sputtering a metal material such as silver or aluminum on the bottom surface of the light emitting element. Thereby, since the light reflectance at the bottom surface of the light emitting element is improved, deterioration of the resin due to light or heat from the light emitting element is suppressed when the bonding member is made of a resin material, and the light extraction efficiency of the light emitting device is improved. Further, a metal layer made of silver or aluminum and then a eutectic layer made of Au or Sn are sequentially laminated from the bottom surface side of the light emitting element. Thereby, light reflectance improves between the bottom face of a light emitting element, and a eutectic layer. In addition, when the eutectic material includes a material that absorbs at least part of light from the light emitting element, light loss on the bottom surface side of the light emitting element is reduced, so that the light extraction efficiency of the light emitting device is improved.

  The light emitting element is fixed to the light emitting element mounting portion provided on the upper surface of the support described later by a bonding member. In this embodiment, the light emitting element is fixed on a metal member provided on the upper surface of the support. However, the present invention is not limited to such a form, and the light emitting element may be mounted on an insulating member constituting the support.

(Conductive wire)
The conductive wire is required to have good ohmic properties, mechanical connectivity, electrical conductivity, and thermal conductivity with the electrode of the light emitting element. Preferably ^{0.01cal / (s) (cm 2} ) (℃ / cm) or higher as heat conductivity, and more preferably ^{0.5cal / (s) (cm 2} ) (℃ / cm) or more. In consideration of workability and the like, the diameter of the conductive wire is preferably Φ10 μm or more and Φ45 μm or less. When the fluorescent material is contained in the translucent member, the conductive wire is easily disconnected at the interface between the portion containing the fluorescent material and the portion not containing the fluorescent material. Therefore, the diameter of the conductive wire is more preferably 25 μm or more, and more preferably 35 μm or less from the viewpoint of securing the light emitting area of the light emitting element and ease of handling. Specific examples of such conductive wires include conductive wires using metals such as gold, copper, platinum, and aluminum, and alloys thereof.

(Support)
The package according to this embodiment includes a support body on which a semiconductor element and an electrode are arranged, and a translucent member that covers the semiconductor element. First, as a support in the light emitting device of this embodiment, a plate-like support in which a conductive wiring is applied to an insulating substrate can be suitably used. A light emitting element is arrange | positioned at the mounting part provided on the main surface of a plate-shaped support body. When a support body without a side wall surrounding the side surface direction of the light emitting element is used, light emitted from the side surface direction of the light emitting element can be extracted outside without loss. The insulating substrate of this embodiment is a rectangular parallelepiped having a substantially rectangular upper surface, and has a concave portion that is recessed from the upper surface side to the bottom surface side at a substantially central portion of the upper surface. Further, two pairs of a metal member for mounting the light emitting element and a pair of positive and negative electrodes are provided on the upper surface of the insulating substrate. The recess is provided between these electrodes and the metal material. In addition, an electrode electrically connected to the electrode provided on the upper surface of the insulating substrate is provided on the bottom surface of the recess. The shape and position of the electrode and metal member provided on the insulating substrate are appropriately determined in consideration of the size and shape of the semiconductor element arranged with the metal member as a mounting portion, the ease of stretching of the conductive wire, and the like. Adjusted.

  The insulating substrate that constitutes the support of this embodiment has a concave portion that is recessed from the top surface side to the bottom surface side in a region outside the region where the light emitting device is mounted on the top surface of the semiconductor substrate on which the semiconductor device is mounted. is doing. For example, a protective element is housed in the recess as a semiconductor element different from the light emitting element. The recess in this embodiment has a substantially square outer shape in plan view of the opening, but is not limited to this, and the shape and size according to the size, number and shape of the semiconductor elements housed in the recess can do. Similarly, the depth of the recess can be appropriately adjusted depending on the height of the semiconductor element to be accommodated and the connection method with the electrode in the recess. As shown in FIG. 1, it is preferable to provide a recess 103 between the mounting portion 104 b of the first light emitting element 101 a and the mounting portion 104 b of the second light emitting element 101 b and in the approximate center of the support body 108. . Thereby, a light emitting device provided with a recess in the corner of the support (for example, when the support is viewed from above, in the longitudinal direction of the support, the first light emitting element mounting portion, the second light emitting element mounting portion, Compared with a light emitting device having a support body arranged in the order of concave portions), the light emitting device in this embodiment can reduce the influence on the light distribution due to the provision of the concave portions in the support body.

  Further, for example, when forming the cavity simultaneously with the formation of the translucent member, the size and depth of the recesses are as follows: the outer shape in plan view of the opening of the recess and the outer shape in plan view of the semiconductor element accommodated in the recess. And the ratio of the depth of the recess to the height of the semiconductor element housed in the recess is preferably 1.0 to 2.14. If the size of the recess becomes too large with respect to the size of the semiconductor element, the bubbles forming the cavity also become larger. This is because there is a concern that the reliability and optical characteristics of the light-emitting device may be deteriorated when such bubbles receive heat generated by the light-emitting element and thermally expand.

  As a material for the insulating substrate, a glass epoxy substrate in which a glass component is contained in an epoxy resin or a substrate made of ceramics can be suitably used.

When a high contrast is required for the light emitting device, it is preferable to make the insulating substrate dark color by including a pigment such as Cr ₂ O ₃ , MnO ₂ , Fe ₂ O _{3 in the} base material of the insulating substrate. . Alternatively, in order to give a high light reflectance to the insulating substrate, it is preferable to contain a white pigment such as titanium dioxide.

In particular, when high heat resistance and high light resistance are desired, it is preferable to use ceramics as a base material of an insulating substrate. The main material of the ceramic is preferably alumina, aluminum nitride, mullite or the like. A ceramic substrate is obtained by adding a sintering aid to these main materials and sintering. For example, 90 to 96% by weight of the raw material powder is alumina, and 4 to 10% by weight of clay , talc, magnesia, calcia, silica and the like are added as sintering aids and sintered in a temperature range of 1500 to 1700 ° C. 40-60% by weight of ceramics and raw material powder is alumina, and 60-40% by weight of borosilicate glass, cordierite, forsterite, mullite, etc. are added as sintering aids and sintered in the temperature range of 800-1200 ° C. And ceramics. Such a ceramic substrate can take various shapes at the green sheet stage before firing. Therefore, an insulating substrate having a recess according to this embodiment can be easily formed. Moreover, conductor wiring of various pattern shapes can be applied at the green sheet stage before firing. For example, by conducting screen printing of a paste-like material containing tungsten, it is possible to form a conductor wiring or a base layer of a metal material for forming a semiconductor element mounting portion. In these underlayers, after firing a ceramic material, a metal material on the outermost surface is disposed by plating or sputtering using silver, gold, or aluminum as a material. The outermost surface is preferably coated with a metal material having a high reflectance with respect to light from the light emitting element.

(Translucent member)
The material of the translucent member is not particularly limited. For example, a translucent material having excellent weather resistance, such as a silicone resin, an epoxy resin, a urea resin, a fluororesin, and a hybrid resin containing at least one of those resins. Can be used. Further, the translucent member is not limited to an organic material, and an inorganic material having excellent light resistance such as glass or silica gel can also be used. Moreover, the translucent member of this embodiment can be added with any member such as a viscosity extender, a light diffusing agent, a pigment, and a fluorescent material depending on the application. For example, a colorant corresponding to the emission color of the light emitting device can be added. Examples of the light diffusing agent include barium titanate, titanium oxide, aluminum oxide, silicon dioxide, calcium carbonate, and a mixture containing at least one of them. Furthermore, a lens effect can be given by making the light-emitting surface side of a translucent member into a desired shape. Specifically, a flat plate shape, a convex lens shape, a concave lens shape, an elliptical shape as viewed from the light emission observation surface, or a shape obtained by combining a plurality of them can be used.

(Fluorescent substance)
In the light-emitting device of this embodiment, the light-transmitting member can contain a fluorescent material. As an example of such a fluorescent material, there is a fluorescent material containing a rare earth element described below.

Specifically, a garnet having at least one element selected from the group of Y, Lu, Sc, La, Gd, Tb, and Sm, and at least one element selected from the group of Al, Ga, and In (Steorite) type fluorescent material. In particular, the aluminum garnet phosphor includes Al and at least one element selected from Y, Lu, Sc, La, Gd, Tb, Eu, Ga, In, and Sm, and is selected from rare earth elements. It is a phosphor activated by at least one element, and is a phosphor that emits light when excited by visible light or ultraviolet light emitted from a light emitting element. For example, in addition to yttrium-aluminum oxide phosphor (YAG phosphor), Tb _2.95 Ce _0.05 Al ₅ O ₁₂ , Y _2.90 Ce _0.05 Tb _0.05 Al ₅ O ₁₂ , Y _2.94 Ce _0.05 Pr _0.01 Al ₅ O ₁₂ , Y _2.90 Ce _0.05 Pr _0.05 Al ₅ O _{12 and the} like. Among these, particularly in the present embodiment, two or more kinds of yttrium / aluminum oxide phosphors containing Y and activated by Ce or Pr and having different compositions are used.

In addition, the nitride-based phosphor contains N and at least one element selected from Be, Mg, Ca, Sr, Ba, and Zn, and C, Si, Ge, Sn, Ti, Zr, and Hf And a phosphor activated by at least one element selected from rare earth elements. Examples of the nitride phosphor include (Sr _0.97 Eu _0.03 ) ₂ Si ₅ N ₈ , (Ca _0.985 Eu _0.015 ) ₂ Si ₅ N ₈ , (Sr _0.679 Ca _0.291). Eu _0.03 ) ₂ Si ₅ N ₈ , and the like.

  Examples according to the present invention will be described in detail below. Needless to say, the present invention is not limited to the following examples.

  FIG. 1 is a top view schematically showing a light emitting device 100 in the present embodiment. 2 is a cross-sectional view schematically showing a cross section when the light emitting device 100 of FIG. 1 is cut in the XX direction. FIG. 3 is a cross section of the light emitting device 100 shown in FIG. 1 in the YY direction. It is sectional drawing which shows a cross section when it did. FIG. 4 is a bottom view schematically showing the light emitting device 100 of this example. FIG. 5 is a perspective view schematically showing the light emitting device 100 of the present embodiment.

  As shown in FIG. 1, the light emitting device 100 in this embodiment includes a flat plate-like support body 108 having a first electrode 104 a and a second electrode 104 c for supplying power to a light emitting element, and the support body 108. A plurality of light emitting elements 101a and 101b arranged with the metal member 104b provided on the upper surface as a mounting portion, the electrodes of the first light emitting element 101a and the second light emitting element 101b, the first electrode 104a and the second electrode A second conductive wire 106 that connects 104c; and a translucent member 107 that covers the light emitting elements 101a and 101b and the second conductive wire 106.

  The light emitting element of this embodiment is two LED chips 101a and 101b that emit blue light using a gallium nitride compound semiconductor as a material. These LED chips have a rectangular shape of 500 μm × 290 μm (length × width) when the top surface is viewed in plan, and a eutectic material containing Au and Sn as materials is disposed on the bottom surface side. Each of these LED chips is bonded with a eutectic material on a mounting portion having silver as the outermost surface provided on the upper surface of the support.

  The support is obtained by plating nickel, gold and silver in this order on an insulating substrate made of ceramics with tungsten as an underlayer. Each electrode and the metal member 104b are formed by arrangement | positioning of these metal materials. Further, the support 108 is provided with a recess 103 having an opening in a region sandwiched between two mounting portions of the LED chip 101a and the LED chip 101b on the upper surface of the insulating substrate. The recess 103 houses a protection element 102 that protects the LED chips 101a and 101b from destruction due to overvoltage. Furthermore, the light emitting device of this embodiment has a cavity 111 between the lower surface of the translucent member 107 covering the opening of the recess 103 and the upper surface of the protection element 102 accommodated in the recess 103.

  The protection element 102 of this embodiment is a Zener diode having electrodes with different polarities on the top surface and the bottom surface. The protective element 102 is bonded to the bottom surface of the recess 103 using silver paste as a conductive adhesive, and the electrode on the bottom surface side is connected to the conductor wiring exposed on the bottom surface of the recess 103 via the conductive adhesive. Yes. The electrode on the upper surface of the protective element 102 is connected to the first electrode 104 a provided on the upper surface of the support via the first conductive wire 105.

  As shown in FIG. 1, the support body 108 of this embodiment has a pair of positive and negative electrodes (first electrode) connected to the light emitting element via the second conductive wire 106 on the upper surface on which the light emitting element is arranged. 104a and a second electrode 104c) and a metal member 104b provided on the upper surface of the same support body, insulated from these electrodes. The two LED chips 101a and 101b are mounted on a metal member 104b provided separately from the electrodes. Thereby, since a heat dissipation path can be provided in the support body separately from the arrangement pattern of the conductor wiring connected to the electrode, a light emitting device with high heat dissipation can be obtained.

  As shown in FIG. 4, in the light emitting device 100 of the present embodiment, a pair of side surfaces facing the longitudinal direction of the support body 108 as viewed from the back direction are cut out, and the inner surface of the cut out portion. The first external connection electrode 110a and the second external connection electrode 110c are extended from the center portion of the support body 108 to the center portion of the support body 108. These first external connection electrode 110a and second external connection electrode 110c are the first electrode 104a, the second electrode 104c, and the bottom surface of the recess 103 disposed on the upper surface of the support body 108 for connection to each semiconductor element. Is electrically connected to the electrode disposed on the surface. That is, the first external connection electrode 110a and the second external connection electrode 110c are electrically connected to the first electrode 104a and the second electrode 104c, respectively, by the conductor wiring embedded in the support body. The first external connection electrode 110a and the second external connection electrode 110c are connected to the wiring board via the solder when the light emitting device 100 is soldered to the external wiring board.

  As shown in FIG. 2 and FIG. 3, the cavity 111 of the present embodiment is formed by bubbles remaining in the recess 103 in the step of forming the translucent member 107 of the light emitting device 100 of the present embodiment. It is a thing. That is, after each semiconductor element is arranged on the support 108 and each electrode is connected by a conductive wire, a silicone resin containing a YAG phosphor is printed so as to cover the light emitting element, the conductive wire, and the opening of the recess. To form. The manufacturing method of the light-emitting device of this example is as follows.

  First, a plurality of LED chips are arranged on a collective substrate of a support 108 made of ceramic as an insulating substrate material, and the protective element 103 is housed in a recess and electrically connected by a conductive wire or the like. The protective element 103 is adhered to the conductor wiring disposed on the bottom surface of the recess using silver paste as an adhesive, and the electrode on the bottom surface of the protective element 103 is electrically connected to the conductor wiring via the silver paste. The

  Next, a silicone resin containing a YAG phosphor is linearly arranged along the arrangement of the LED chips so that the plurality of LED chips are collectively covered with the conductive wires and the openings of the recesses. At this time, the viscosity of the silicone resin containing the YAG phosphor is set to 300 Pa · s. In addition, the protective element of this example is a square having an outer dimension of 240 μm × 240 μm when the upper surface is viewed in plan, and the height when arranged on the bottom surface of the recess is 0.14 mm. When the protective element having such a size is housed in the recess, the outer dimension of the opening of the recess is preferably a square having a side of 0.24 mm or more and 0.60 mm or less, from the upper surface of the opening to the bottom of the recess. The depth is preferably 0.15 mm or more and 0.30 mm or less. In the present embodiment, the outer dimension of the opening of the recess is a square of 0.50 mm × 0.50 mm, and the depth is 0.15 mm. Further, after the silicone resin is cured, the light-transmitting member and the insulating substrate are cut by dicing and separated into a predetermined size to obtain the light emitting device 100 of this embodiment.

  Note that marks (marks made of a straight line or an L-shape) 109 formed at four corners or sides of the rectangle forming the outer shape of the upper surface of the support 108 are a pair of positive and negative external connection electrodes 110 a provided in the light emitting device 100. 110c can be used as a mark for indicating a dicing line when the collective substrate is diced into individual pieces.

  The present invention can be used for illumination light sources, various indicator light sources, in-vehicle light sources, display light sources, liquid crystal backlight light sources, and the like.

FIG. 1 is a top view schematically showing a light emitting device according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing a cross section of the light emitting device in the XX direction shown in FIG. FIG. 3 is a cross-sectional view schematically showing a cross section of the light emitting device in the YY direction shown in FIG. FIG. 4 is a bottom view schematically showing a light emitting device in one embodiment of the present invention. FIG. 5 is a perspective view schematically showing a light emitting device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view schematically showing a cross section of a light emitting device according to another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100, 200 ... Light-emitting device 101a, 101b ... Light-emitting element 102 ... Semiconductor element 103 ... Recess 104a ... First electrode 104b ... Metal member 104c ... Second electrode 105 ... first conductive wire 106 ... second conductive wire 107 ... translucent member 108 ... support 109 ... mark 110a ... first external connection electrode 110c ..Second external connection electrode 111 ... cavity 112 ... projection

Claims (11)

A light emitting element; a package in which the light emitting element is disposed; and an electrically conductive wire that connects an electrode provided in the package and an electrode of the light emitting element. The package disposes the light emitting element. A light-emitting device comprising: a support having a recess for housing a semiconductor element different from the mounting part and the light-emitting element; and a translucent member disposed on the support,
The translucent member covers at least the light emitting element and the opening of the recess, and a cavity is provided between the side surface of the semiconductor element housed in the recess and the inner wall surface of the recess. emitting device characterized by there. 2. The light emitting device according to claim 1, wherein the cavity is further provided between a bottom surface of a translucent member covering the opening of the recess and an upper surface of the semiconductor element housed in the recess.   The light-emitting device according to claim 1, wherein the translucent member has a protruding portion that is convex from the opening of the recess toward the bottom surface of the recess.   The said recessed part is provided in the area | region pinched | interposed into the some mounting part of the said light emitting element, The said support body is provided with the external connection electrode substantially directly under the said mounting part, respectively. A light-emitting device according to claim 1.   5. The similarity ratio between the outer shape of the opening of the recess in plan view and the outer shape of the semiconductor element housed in the recess in plan view is 1.0 to 2.5. The light emitting device according to 1. A light emitting element, a package in which the light emitting element is disposed, and an electrode provided on the package and a conductive wire that connects the electrode of the light emitting element, and the package covers at least the light emitting element. A light-emitting device comprising: a light-transmitting member; a mounting portion on which the light-emitting element is disposed; and a support body that has a recess that houses a semiconductor element different from the light-emitting element.
A first step of forming a support having a recess opening on an upper surface on which the light emitting element is mounted;
A second step of disposing the upper surface of the semiconductor element below the upper surface of the mounting portion of the light emitting element and storing the semiconductor element in the recess;
A third step of disposing the light emitting element and the conductive wire;
And a fourth step of disposing a translucent member covering at least the light emitting element and the opening of the recess on the support while forming a cavity in the recess. Method.   The light emitting device manufacturing method according to claim 6, wherein the fourth step includes a step of continuously supplying a material of the light transmissive member in a direction substantially parallel to an upper surface on which the light emitting element is mounted. Method.   The viscosity of the material of the translucent member is adjusted based on the size of the recess with respect to the semiconductor element so that bubbles remain in the recess in the fourth step. Manufacturing method of light-emitting device.   The light-emitting device according to claim 7 or 8, wherein the material of the translucent member includes at least one resin selected from a silicone resin or an epoxy resin, and the resin contains a particulate phosphor. Manufacturing method.   The method for manufacturing a light emitting device according to claim 8 or 9, wherein the material of the light transmissive member has a viscosity of 200 Pa · s to 500 Pa · s.   The similarity ratio between the outer shape of the opening of the recess in plan view and the outer shape of the semiconductor element accommodated in the recess in plan view is 1.0 to 2.5, and the depth of the recess and the recess The method for manufacturing a light emitting device according to any one of claims 6 to 10, wherein a ratio to a height of the housed semiconductor element is 1.0 to 2.14.

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