JP3972889B2 - Light emitting device and planar light source using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device reduced in thickness wherein light from a light emitting element is led without a loss to a light guiding board to land on a large area of the light receiving surface of the light guiding board, and to provide a planar light source using the same. <P>SOLUTION: The light emitting device has a light emitting element and a package which has an opening for accommodating the light emitting element, and from which a part of the main surface of a lead electrode mounted with the light emitting element is exposed in the bottom surface of the opening. The opening has a protruding section (111), and the inner walls of the opening comprise an inner wall surface (101a) extending in the direction of the major axis of the package main surface, a pair of inner wall surfaces (102) extending in the direction of the minor axis and facing each other, an inner wall surface (101b) facing the inner wall surface (101a), an inner wall surface (101c) facing the inner wall surface (101a) and laid on the protruding section surface (111), and an inner wall surface (104) which is laid on the protruding section (111) and continues from the inner wall surface (101b) to the inner wall surface (101c). <P>COPYRIGHT: (C)2004,JPO&amp;NCIPI

Description

  The present invention relates to a light emitting device and a planar light source used for a liquid crystal backlight, a panel meter, an indicator lamp, a surface emitting switch, and the like.

  Today, light emitting diodes capable of emitting RGB colors and light emitting diodes capable of emitting white light with high brightness have been developed. As a result, light sources configured by arranging multiple light emitting devices are used in various fields. Has been.

  For example, a planar light source for a liquid crystal backlight includes a light guide plate that is a light-transmissive member that guides light incident on an end surface to a light emission observation surface, and a plurality of surface-mounted light-emitting devices. This is a planar light source in which incident light is reflected inside the light guide plate and emitted from the light emission observation surface. A surface-mounted light-emitting device that constitutes such a planar light source includes a package having an opening for housing a light-emitting element, and an optical axis in a direction substantially parallel to a mounting surface with a substrate provided with a conductive pattern. The light is emitted from the end face of the light guide plate (see, for example, Patent Document 1).

JP-A-8-264842.

  However, as the planar light source becomes thinner, the light emitting device is also required to be thinner. When attempting to reduce the thickness of a light emitting device including a package having the opening, the distance between the inner wall surface of the opening and the side surface of the light emitting element varies depending on the direction of each side surface of the light emitting element. Then, the light traveling from the side surface of the light emitting element to the inner wall surface having a large distance is attenuated or scattered by the filler in the opening such as the sealing member before reaching the inner wall surface, and is in a direction different from the front direction. May progress. Such light is wasted without causing light emission unevenness or being incident on the light guide plate. Also, if the size of the entire light emitting device is reduced in an attempt to bring the inner wall surface of the opening close to the light emitting element, it may be difficult to properly arrange the lead electrode that supplies power to the light emitting element, It may be difficult to firmly fix the light guide plate. Furthermore, when a planar light source is to be formed with the number of light emitting devices being minimized, a light emitting device capable of entering light in a wide range with respect to the end surface of the light guide plate is desired.

  Therefore, the present invention allows light emitted from the light emitting element to be incident on the light guide plate without waste, and allows light to be incident in a wide range on the light incident surface of the light guide plate while reducing the thickness as compared with the prior art. It is an object to provide a light emitting device and a planar light source using the light emitting device.

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 a lead electrode is exposed on the bottom surface of the opening where the light-emitting element is disposed, and a light-emitting device disposed on the bottom surface of the opening. A light-emitting device including a conductive wire connecting an electrode of an element and the lead electrode, wherein the inner wall surface of the opening is a first inner wall surface extending in a longitudinal direction of the main surface of the package A pair of second inner wall surfaces extending in the short direction of the main surface of the package and facing each other; a third inner wall surface connected to the second inner wall surface and opposed to the first inner wall surface; And a fourth inner wall surface facing the first inner wall surface, and a fifth inner wall surface connecting the fourth inner wall surface and the third inner wall surface, and the opening. One of the fourth inner wall surface and the pair of opposing fifth inner wall surfaces. Has a protruding portion provided to protrude to the outer wall surface side of the package, and at least a part of the light emitting element is disposed on the bottom surface of the protruding portion, and between a pair of opposing second inner wall surfaces The conductive wire is wire-bonded to the lead electrode exposed in step (1).

  The inner wall surface (104) faces a plurality of side surfaces of the light emitting element. With this configuration, the light extraction efficiency of the light-emitting device can be improved and light can be emitted in a wide range even when the side surface of the light-emitting element is mounted in a positional relationship that is not parallel to the other inner wall surface of the opening. The thin light-emitting device can be obtained.

  Furthermore, it is preferable that at least a part of the light emitting element is placed on the bottom surface of the protruding portion (111). By bringing the side surface of the light emitting element close to the inner wall surface 104, light from the light emitting element can be efficiently reflected by the inner wall surface 104 toward the light emission observation surface.

  The light emitting element and the lead electrode are electrically connected by a conductive wire, and a metal piece of the conductive wire is placed on the lead electrode exposed between the pair of inner wall surfaces (102). Is done. With this configuration, light traveling from the light emitting element toward the inner wall surface (104) enters the inner wall surface (104) without being blocked by the metal piece portion of the conductive wire placed on the lead electrode. The light can be reflected by the inner wall surface (104) in the direction of the light emission observation surface.

  Moreover, the said package has a level | step difference or a recessed part in the side surface. If comprised in this way, highly accurate position alignment with a light-guide plate is easy, and it can fix to a light-guide plate firmly.

  The outer wall surface of the package facing the inner wall surface (101) is substantially flush with the mounting surface of the lead electrode on the mounting surface side of the light emitting device. With this configuration, the light emitting device can be stably mounted on the mounting surface, and the light emitting surface of the light emitting device can be widened.

  The light emitting element includes Al and at least one element selected from Y, Lu, Sc, La, Gd, Tb, Eu, Ga, In, and Sm, and at least one element selected from rare earth elements. And at least one element selected from Be, Mg, Ca, Sr, Ba, and Zn, and C, Si, Ge, Sn, Ti, Zr, and And at least one phosphor selected from phosphors including at least one element selected from Hf and activated by at least one element selected from rare earth elements. With this configuration, a light-emitting device that emits mixed light of light from a light-emitting element and light emitted from a fluorescent material excited by the light can be provided.

  In addition, the present invention includes the light emitting device and a planar light guide plate that guides light from the light emitting device, and the planar light guide plate can be fitted to the outer wall surface shape of the light emitting device. A planar light source characterized by having a shape. If comprised in this way, the mounting precision at the time of attaching a light-emitting device to a light-guide plate can be improved. The planar light source according to the present invention is a planar light source capable of uniform light emission without unevenness of light emission depending on the light emission position.

  According to the present invention, the light emitted from the light emitting element can be incident on the light guide plate without waste, and the light emitting device can make light incident on the light incident surface of the light guide plate in a wide range while being thinner than the conventional one. And it can be set as a planar light source using the same.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the embodiment described below exemplifies a light emitting device and a planar light source for embodying the technical idea of the present invention, and the present invention limits the light emitting device and the planar light source to the following. is not. Further, the size and positional relationship of the members shown in the drawings are exaggerated for clarity of explanation.

  In a light emitting device comprising: a light emitting element; and a package that includes an opening that houses the light emitting element, and a package in which a part of the main surface of the lead electrode on which the light emitting element is mounted is exposed from the bottom surface of the opening. As a result of various experiments, the inventor has partially included a protrusion (111) in which the opening protrudes toward the outer wall surface of the package, and the inner wall surface of the opening extends in the major axis direction of the package main surface. A wall surface (101a), a pair of inner wall surfaces (102) that extend in the minor axis direction and face each other, an inner wall surface (101b) that faces the inner wall surface (101a), and a protruding portion that faces the inner wall surface (101a) ( 111) and an inner wall surface (104) continuously provided as an inner wall surface of the protruding portion at a predetermined angle from the inner wall surface (101b) to the inner wall surface (101c). A device. As a result, it has been found that light from the light emitting element can be taken out widely to the outside of the light emitting device without waste, and the present invention has been achieved.

  That is, in the light emitting device of the present embodiment, the opening of the package is formed by integrally forming a positive lead electrode and a negative lead electrode with a molding resin as shown in FIG. More specifically, the package has an opening capable of accommodating a light emitting element chip on the main surface side, and one end of a positive lead electrode and a negative lead electrode are formed on the bottom surface of the opening. Molding resin is filled between the positive lead electrode and the negative lead electrode so that the one end faces each other and a part of each main surface is exposed to be insulated. Here, in this specification, the “main surface” in each member refers to a surface on the light emission observation surface side on the side where light is emitted from the light emitting device. For example, the “main surface of the package” refers to a surface of the outer wall surface of the package that faces the front surface of the light emitting device and includes the light emitting surface of the light emitting device and has an opening.

  In the light emitting device of this embodiment, the positive lead electrode and the negative lead electrode are inserted so that the other end protrudes from the package end surface. The protruding lead electrode portion is bent toward the inner side opposite to the main surface of the package or toward a surface perpendicular to the main surface. The light-emitting device of the present embodiment has a mounting surface that is substantially perpendicular to the main surface of the package or parallel to the longitudinal direction of the opening, and has an optical axis in a direction substantially parallel to the mounting surface. This is a side-emitting light-emitting device that can emit such light.

  The package used for the light-emitting device of this embodiment has a step or a recess in part of its outer wall surface. Thereby, positioning with the optical member which has a shape which can be fitted with the level | step difference or recessed part of a package outer wall surface can be performed easily. That is, in the light emitting device of the present invention, when an optical member such as a lens is provided to improve luminance or a light guide plate is provided to form a planar light source, these can be fitted to the outer wall surface of the package. By processing into a simple shape, a planar light source that can be easily assembled with high accuracy and is excellent in mass productivity and optical characteristics can be obtained.

  The package of the present embodiment has an opening on the main surface side in which a light emitting element can be stored. Furthermore, the opening part has a protruding part (for example, shown as a shaded area in part of the opening part in FIG. 1) protruding on the outer wall surface side of the package, that is, the mounting surface side of the light emitting device. is doing. The inner wall surface of the opening in this embodiment includes an inner wall surface (101a) extending in the major axis direction of the package main surface, and an inner wall surface (102) extending in the minor axis direction and adjacent to the inner wall surface (101a). An inner wall surface (101b) facing the inner wall surface (101a) extending in the major axis direction and adjacent to the inner wall surface (102), and an inner wall surface (101c) facing the inner wall surface (101a) and provided on the protruding portion And an inner wall surface (104) that is continuously provided on the protruding portion at a predetermined angle from the inner wall surface (101b) to the inner wall surface (101c). In the present embodiment, the predetermined angle is an angle that is neither parallel nor perpendicular to the inner wall surfaces 101a, 101b, and 101c and that is not perpendicular or parallel to at least one of the inner wall surfaces 102 facing each other. The angle is adjusted so that light from the light emitting elements can be efficiently reflected in the front direction of the light emitting device according to the number, size, and shape of the light emitting elements placed in the opening. For example, among the inner wall surfaces forming the opening as shown in FIG. 1, the inner wall surface 104 gradually approaching from the inner wall surface 102 side toward the side surface of the light emitting element, and the inner wall surface 104 from the side surface of the light emitting element. It has at least the inner wall surface 102 arranged far away. Further, the inner wall surface extending in the mounting surface direction from the upper surface side of the light emitting device includes an inner wall surface 101a, an inner wall surface 102 substantially perpendicular to the inner wall surface 101a, an inner wall surface 101b facing substantially parallel to the inner wall surface 101a on the upper surface side, The inner wall surface 104 formed obliquely from the inner wall surface 101b is continuous with the inner wall surface 101c on the mounting surface side. Here, the inner wall surface 104 is preferably opposed to an arbitrary side surface of the light emitting element 107 placed on the bottom surface of the opening and a side surface adjacent to the side surface.

  In this embodiment, the inner wall surface 104 continues to the inner wall surface 101b or the inner wall surface 101c at a predetermined angle. That is, as shown in FIG. 1, the inner wall surface 104 is continuous with the inner wall surface 101c so as to form an obtuse angle in the direction of the opening. However, the shape of the opening according to the present invention can be various shapes depending on the light distribution of the light emitting device and the shape of the light emitting element to be mounted, and is not limited to the above-described form. That is, in another form, as shown in FIG. 7, the inner wall surface 104 may continuously form a curved surface with respect to the inner wall surface 101b or the inner wall surface 101c, and as shown in FIG. You may continue so that it may become a right angle. Furthermore, the inner wall surface 104 may be convex in the direction of the light emitting element 107, or may be a curved surface having a concave shape as shown in FIG. Alternatively, the inner wall surface 104 may be continuous at an angle that is substantially flush with the inner wall surface 101b. Further, as shown in FIG. 8, the light emission observation surface is arranged so that the inner wall surface 104 faces the side surface of the light emitting element 107 at substantially equal intervals corresponding to the shape of the light emitting element placed on the bottom surface in the opening. Each inner wall surface may be formed such that the shape of the opening is asymmetrical in the short axis direction when viewed from the direction. Further, as shown in FIG. 10, the inner wall surface 104 may be formed by a plurality of divided inner wall surfaces.

  Conventionally, when a light-emitting device having a package without the inner wall surface 104 is used, the light emitted from the light-emitting device and traveling to the inner wall surface 102 is attenuated or scattered in the middle by a filler in an opening such as a sealing member. As a result, there was little light emitted from the front direction of the light emitting device. However, by providing the inner wall surface 104 closer to the side surface of the light emitting element as in the present invention, the light traveling from the light emitting element to the inner wall surface 104 is scattered in the middle of the light emitted from the light emitting element. Alternatively, since light is immediately reflected by the inner wall surface 104 toward the main surface of the light emitting device without being attenuated, the light extraction efficiency of the light emitting device can be improved. In addition, even when the position where the light emitting element is placed on the lead electrode main surface is deviated from the predetermined position, one of the side surfaces of the light emitting element faces the inner wall surface 104 and the distance from the light emitting element side surface to the inner wall surface Can be increased, and the amount of light reflected in the direction of the main surface of the light emitting device can be increased. Further, since the opening partly has the inner wall surface 102, the light that has traveled without being reflected by the inner wall surface 104 is also reflected by the inner wall surface 102, and the light travels over a wide range in the major axis direction of the opening. Can be irradiated. As described above, the present invention makes it possible to improve both the light extraction efficiency of the light-emitting device and the wide-area light irradiation property.

  The shape of the inner wall surface of the opening is preferably a reflector shape that tapers in the opening direction. Thereby, the light emitted from the end face of the light emitting element can be efficiently reflected and extracted in the front direction. Further, in order to increase the reflectance of light, a layer having a reflection function such as a metal plating of silver or the like may be formed on the inner wall surface of the opening.

  The outer wall surface of the package facing the inner wall surface 101 is preferably substantially flush with the mounting surface of the lead electrode 103 on the mounting surface side of the light emitting device. By arranging in this manner, the light emitting device can be stably mounted on the mounting surface, and by making the light emitting surface wide, a light emitting device that emits light over a wide range of the opening can be obtained.

  The light emitting device of the present embodiment is configured by providing a light emitting element in the opening of the package configured as described above, and filling the opening with a translucent resin so as to cover the light emitting element chip. Next, each component will be described in detail according to the method for manufacturing the light emitting device of the present embodiment.

[Step 1: Formation of lead electrode]
In the present embodiment, as a first step, punching using a press is performed on a long metal plate made of iron-containing copper having a thickness of 0.15 mm, and a plurality of portions to be positive and negative lead electrodes of each package are formed. Ag plating is applied to the long metal plate that has been paired and punched. Note that a hanger lead for supporting the package from the step of forming the package 106 to the step of separating the light emitting device can be provided on a part of the long metal plate. At this time, after forming described below, the support by the hanger lead is removed. By using the hanger lead, the forming process can be performed for each pair of lead electrodes, so that the number of processes can be reduced and the workability can be improved as compared with the case of performing each package individually.

  Here, the material of the lead electrode is not particularly limited as long as it can conduct electricity. However, the lead electrode is required to have good connectivity and electrical conductivity with a conductive wire or a conductive bump which is a member electrically connected to the semiconductor element. It is done. Moreover, the material of the lead electrode is required to have good adhesion to the solder material used for connection with the conductive pattern provided on the mounting substrate. The specific electric resistance is preferably 300 μΩ-cm or less, more preferably 3 μΩ-cm or less. Suitable materials that satisfy these conditions include iron, copper, iron-containing copper, tin-containing copper and copper, gold, silver plated aluminum, iron, copper, and the like.

  In the portion corresponding to each package of the long metal plate after press working, the positive lead electrode has a negative lead so that one end face thereof faces one end face of the negative lead electrode at the bottom face of the opening after forming. It is separated from the electrode. In this embodiment, the lead electrode exposed in the opening is not specially processed, but it is also possible to increase the bonding strength with the molding resin by providing at least a pair of through holes on the left and right with the opening in the longitudinal direction as an axis. Is possible.

[Step 2: Molding of package]
Next, the long metal plate is disposed between a convex mold and a concave mold which are molding dies, and these molds are closed. It is preferable that the size of one opening of the mold is small enough to fit in the opening of the other mold. By doing so, the molds do not move during molding, and a package having a certain thickness can be obtained. A molding material is injected into a hollow portion obtained by closing these molds from a gate provided on the back surface of the concave mold. The cavity corresponds to the outer shape of the package forming member. The molding die for molding the molded resin part has a step on a part of the side surface, and a package having an opening having inner wall surfaces 101a, 101b, 101c, inner wall surface 102 and inner wall surface 104 is obtained. It has a shape like this. Also, in the molding die, the long metal plate that has been pressed may be inserted and disposed between the convex die and the concave die so that the stamping direction of the press matches the direction of injecting the resin into the molding die. preferable. When the arrangement direction of the long metal plate is determined in this way, the resin formed in the space formed by the one end surfaces of the positive and negative lead electrodes can be filled with no gap, and on one main surface of the injected molding resin Can be prevented.

  The molding material used in the present invention is not particularly limited, and any conventionally known thermosetting resin such as liquid crystal polymer, polyphthalamide resin, polybutylene terephthalate (PBT), and the like can be used. In particular, when a polyamide-based resin obtained from a diamine having 6 to 9 carbon atoms and terephthalic acid, for example, a semi-crystalline polymer resin containing a high melting point crystal such as a polyphthalamide resin is used, the surface energy is large. A package having good adhesion to a sealing resin that can be provided inside the opening, a light guide plate that can be attached later, and the like can be obtained. Thereby, in the process of filling and curing the sealing resin, it is possible to suppress the occurrence of peeling at the interface between the package and the sealing resin during the cooling process. Moreover, in order to reflect the light from a light emitting element chip | tip efficiently, white pigments, such as a titanium oxide, can be mixed in a package shaping | molding member. Also, considering the case where a light emitting device is mounted on an external substrate with a conductive pattern using a solder material having a melting point higher than that of a conventional solder material such as lead-free solder, the molding material in this embodiment is It is preferable to use a material having heat resistance that can withstand the melting point of the high melting point solder material during the curing. In addition, it is preferable to use a light-resistant material that hardly deteriorates even when exposed to high-output light from a light-emitting element. In terms of these points, the above-described polyamide-based resin is a resin excellent in heat resistance and light resistance as a molding material for a package.

[Step 3: Placement of Light Emitting Element]
(Light emitting element 107)
The molded member formed as described above is removed from the mold. Next, the light emitting element chip is fixed on the lead electrode exposed on the bottom surface of the package opening. Here, at least a part of the light emitting element is preferably placed on the bottom surface of the protrusion (111). Thereby, the light from the light emitting element can be efficiently reflected by the inner wall surface 104 toward the light emission observation surface.

In the present invention, the light-emitting element is not particularly limited, but when a fluorescent material is used together, a semiconductor light-emitting element having a light-emitting layer capable of emitting a wavelength capable of exciting the fluorescent material 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). The nitride semiconductor may contain boron or phosphorus as desired. Examples of the semiconductor structure include a homostructure having a MIS junction, a PIN junction, and a pn junction, a heterostructure, and a double heterostructure. Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal. In addition, a single quantum well structure or a multiple quantum well structure in which the semiconductor active layer is formed in a thin film in which a quantum effect is generated can be used.

  When a nitride semiconductor is used, a material such as sapphire, spinel, SiC, Si, ZnO, or GaN is preferably used for the semiconductor substrate. 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. For example, a buffer layer such as GaN, AlN, or GaAIN is formed on a sapphire substrate, and a nitride semiconductor having a pn junction is formed thereon. The substrate can also be removed after the semiconductor layer is laminated.

As an example of a light emitting device having a pn junction using a nitride semiconductor, a first contact layer formed of n-type gallium nitride, a first cladding layer formed of n-type aluminum nitride / gallium, and a nitride layer on a buffer layer Examples include a double hetero structure in which an active layer formed of indium gallium, a second cladding layer formed of p-type aluminum nitride / gallium, and a second contact layer formed of p-type gallium nitride are sequentially stacked. Nitride semiconductors exhibit n-type conductivity without being doped with impurities. When forming a desired n-type nitride semiconductor, for example, to improve luminous efficiency, it is preferable to appropriately introduce Si, Ge, Se, Te, C, etc. as an n-type dopant. On the other hand, when forming a p-type nitride semiconductor, the p-type dopants such as Zn, Mg, Be, Ca, Sr, and Ba are doped. Since nitride semiconductors are not easily converted to p-type by simply doping with a p-type dopant, it is preferable to reduce resistance by heating in a furnace or plasma irradiation after introducing the p-type dopant. After the electrodes are formed, a light emitting element made of a nitride semiconductor can be formed by cutting the semiconductor wafer into chips. Further, if an insulating protective film made of SiO ₂ or the like is formed by patterning so as to expose only the bonding portions of the electrodes and cover the entire element, a miniaturized light emitting device can be formed with high reliability. When white light is emitted in the light emitting diode of the present invention, the emission wavelength of the light emitting element is preferably 400 nm or more and 530 nm or less, taking into consideration the complementary color relationship with the emission wavelength from the fluorescent material, deterioration of the translucent resin, and the like. 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. Note that a light-emitting element having a main light emission wavelength in an ultraviolet region shorter than 400 nm or a short wavelength region of visible light can be used in combination with a member that is relatively difficult to be deteriorated by ultraviolet rays.

(Bump 118)
In the present embodiment, when a light emitting element chip is mounted by a flip chip method in which a pair of electrodes provided on the same surface is opposed to a pair of lead electrodes exposed from a package opening, light is emitted to the light emitting surface. There is nothing that blocks the light, and uniform light emission can be obtained. The material of the bump is not particularly limited as long as it is conductive, but it is preferable to have at least one of materials contained in both the positive and negative electrodes and the positive and negative lead electrodes of the light emitting element. In the present embodiment, bumps made of Au can be formed on each lead electrode, and the electrodes of the light emitting element can be opposed to each bump and bonded by ultrasonic waves.

(Conductive wire 108)
Instead of the electrical connection by the bumps as described above, the light emitting element chip is die-bonded on one lead electrode with an epoxy resin or the like, and then each electrode of the light emitting element chip and the lead electrode are respectively connected by conductive wires. You may connect. Alternatively, each electrode of the conductive pattern disposed on the submount on which the light-emitting element is flip-chip mounted may be connected to the lead electrode by a conductive wire.

A conductive wire for electrically connecting the light emitting element and the lead electrode is required to have good ohmic properties, mechanical connectivity, electrical conductivity and thermal conductivity with the electrode of the light emitting element chip. 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. In particular, the conductive wire is easily disconnected at the interface between the coating portion containing the fluorescent material and the sealing member not containing the fluorescent material. Even if the same material is used, it is considered that wire breakage is likely because the substantial amount of thermal expansion differs depending on 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 light emitting area 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. Further, it is preferable that the portion where the conductive wire is die-bonded to the lead electrode has a metal piece that covers a part of the linear portion of the conductive wire and has the same material as the conductive wire. By having the metal piece in this way, the conductive wire is firmly fixed to the lead electrode. Therefore, a highly reliable light-emitting device in which disconnection or the like does not occur even when the sealing member receives thermal stress can be obtained. Further, the metal piece of the conductive wire was exposed between the pair of inner wall surfaces (102), that is, in a region sandwiched between one inner wall surface (102) and the other inner wall surface (102) opposite to the inner wall surface (102). It is preferable to be placed on the lead electrode. Thereby, the light from the light emitting element can enter the inner wall surface 104 without being blocked by the metal piece of the conductive wire.

[Step 4: Formation of sealing member]
Next, a sealing member is provided in the opening of the package to protect the light emitting element chip from the outside. The sealing member is not particularly limited as long as it is translucent. Conventionally known resin materials such as a translucent resin having excellent weather resistance, such as a silicone resin, an epoxy resin, a urea resin, a hybrid resin, and a fluororesin Is filled in the opening of the package and cured. Further, the sealing member is not limited to an organic material, and a translucent inorganic member, glass, or the like generated by a sol-gel method using a metal alkoxide as a starting material can also be used. Further, in this embodiment, the sealing member includes a viscosity extender, barium titanate, titanium oxide, aluminum oxide, silicon oxide, silicon dioxide, heavy calcium carbonate, light calcium carbonate, and other light diffusing agents, pigments, and fluorescent substances. Any member can be added depending on the application. Furthermore, a lens effect can be provided by making the light emitting surface side of the sealing member have a desired shape, and light emitted from the light emitting element chip can be focused. Specifically, 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 present invention, when a light-emitting element is used as a semiconductor element, a sealing member that covers the light-emitting element in a semiconductor element structure of the light-emitting element, a die bonding material that fixes the light-emitting element to a support or a lead electrode, a light-emitting element and a submount Various fluorescent materials such as an inorganic fluorescent material and an organic fluorescent material can be disposed in and / or around each constituent member such as an underfill and a package. In particular, the fluorescent material combined with the sealing member is provided outside the sealing member so as to cover the light emission observation surface side surface of the sealing member, and from the light emission observation surface side surface of the sealing member and the light emitting element. It can also be provided inside the sealing member as a layered or filter-like wavelength conversion member containing a phosphor at a spaced position.

  The phosphor that can be used in the present invention absorbs part of visible light and ultraviolet light emitted from the light emitting element, and emits light having a wavelength different from the wavelength of the absorbed light. In particular, the phosphor used in this embodiment refers to a phosphor that emits a wavelength-converted light that is excited by at least light emitted from the light-emitting element, and constitutes a wavelength conversion member together with a binder that fixes the phosphor. To do.

  When the light emitted from the light-emitting element and the light emitted from the phosphor are in a complementary color relationship or the like, white mixed color light can be emitted by mixing each light. Specifically, the light emitted from the light emitting element and the phosphor light excited and emitted thereby correspond to the three primary colors of light (red, green, and blue), or the blue light emitted from the light emitting element. And yellow light of a phosphor that is excited to emit light.

  The emission color of the light-emitting device can be adjusted in various ways such as the ratio between the phosphor and various members such as various resins and glass that act as a binder for the phosphor, the specific gravity of the phosphor, the amount and shape of the phosphor, and By selecting the light emission wavelength of the light emitting element, it is possible to change the color temperature of the mixed color light and provide an arbitrary white color tone such as light in the light bulb color region. It is preferable that the light from the light emitting element and the light from the phosphor are efficiently transmitted through the sealing member to the outside of the light emitting device.

  Since such a phosphor settles under its own weight in the gas phase or liquid phase, it is dispersed and uniformly released in the gas phase or liquid phase, and in particular in the liquid phase, the suspension is allowed to stand, A layer having a phosphor with higher uniformity can be formed. Furthermore, a desired phosphor amount can be formed by repeating a plurality of times as desired.

  Two or more kinds of phosphors formed as described above may be present in a single-layer wavelength conversion member on the surface of the light-emitting device, or one or two of each of the two-layer wavelength conversion member. There may be more than one type. In this way, white light can be obtained by mixing colors from different types of phosphors. In this case, it is preferable that the average particle diameters and shapes of the phosphors are similar in order to better mix the light emitted from the phosphors and reduce color unevenness.

  Here, the particle size of the phosphor in the present specification is a value obtained by a volume-based particle size distribution curve, and the volume-based particle size distribution curve can measure the particle size distribution of the phosphor by a laser diffraction / scattering method. It is Specifically, in an environment where the temperature is 25 ° C. and the humidity is 70%, the phosphor is dispersed in a sodium hexametaphosphate aqueous solution having a concentration of 0.05%, and a laser diffraction particle size distribution analyzer (SALD-2000A) It was obtained by measuring in a particle size range of 0.03 μm to 700 μm.

  The phosphor used in the present embodiment is a combination of an aluminum garnet phosphor typified by a YAG phosphor and a phosphor capable of emitting red light, particularly a nitride phosphor. Can also be used. These YAG phosphors and nitride phosphors may be mixed and contained in the wavelength conversion member, or may be separately contained in the wavelength conversion member composed of a plurality of layers. Hereinafter, each phosphor will be described in detail.

(Aluminum / garnet phosphor)
The aluminum garnet phosphor used in the present embodiment includes Al and at least one element selected from Y, Lu, Sc, La, Gd, Tb, Eu, and Sm, and Ga and In. It is a phosphor that contains one selected element and is activated by at least one element selected from rare earth elements, and is a phosphor that emits light when excited by visible light or ultraviolet light emitted from an LED chip. .

For example, 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. Further, in the present embodiment, two or more types of yttrium / aluminum oxide phosphors (hereinafter referred to as “YAG / aluminum garnet phosphors”) containing Y and activated by Ce or Pr and having different compositions. Called "system phosphor"))). In particular, at the time of high luminance and long-term use _{(Re 1-x Sm x)} 3 (Al 1-y Ga y) 5 O 12: Ce (0 ≦ x <1,0 ≦ y ≦ 1, where, Re Is at least one element selected from the group consisting of Y, Gd, and La).

_{(Re 1-x Sm x)} 3 (Al 1-y Ga y) 5 O 12: Ce phosphor, for garnet structure, heat, resistant to light and moisture, the peak of the excitation spectrum can be like in the vicinity of 470nm Can do. In addition, the emission peak is in the vicinity of 530 nm, and a broad emission spectrum that extends to 720 nm can be provided.

In the light emitting device of the present invention, the phosphor may be a mixture of two or more phosphors. That is, speaking the YAG fluorescent material described above, Al, Ga, Y, the content of La and Gd and Sm are two or more kinds of _{(Re 1-x Sm x)} 3 (Al 1-y Ga y) 5 O ₁₂ : Ce phosphors can be mixed to increase RGB wavelength components. At present, there are variations in the emission wavelength of the semiconductor light emitting device, so that two or more kinds of phosphors can be mixed and adjusted to obtain a desired white mixed color light or the like. Specifically, by adjusting the amount of phosphors having different chromaticity points according to the emission wavelength of the light-emitting element, the light is emitted at any point on the chromaticity diagram connected between the phosphors and the light-emitting element. be able to.

  Blue light emitted from a light emitting device using a nitride compound semiconductor in the light emitting layer, green light emitted from a phosphor whose body color is yellow to absorb blue light, red light, When mixed color display is performed, a desired white light emission color display can be performed. In order to cause this color mixture, the light emitting device can contain phosphor powder and bulk in various resins such as epoxy resin, acrylic resin or silicone resin, and translucent inorganic materials such as silicon oxide and aluminum oxide. Thus, the thing containing the fluorescent substance can be variously used according to uses, such as a dot-like thing and a layer-like thing formed so thinly that the light from the LED chip is transmitted. By adjusting the ratio, coating, and filling amount of the phosphor and the translucent inorganic substance and selecting the emission wavelength of the light emitting element, it is possible to provide an arbitrary color tone such as a light bulb color including white.

  In addition, by arranging two or more kinds of phosphors in order with respect to the incident light from the light emitting element, a light emitting device capable of efficiently emitting light can be obtained. That is, on a light emitting element having a reflective member, a color conversion member containing a phosphor that has an absorption wavelength on the long wavelength side and can emit light at a long wavelength, and an absorption wavelength on the longer wavelength side that has a longer wavelength. The reflected light can be used effectively by laminating a color conversion member capable of emitting light at a wavelength.

When a YAG phosphor is used, sufficient light resistance with high efficiency even when it is placed in contact with or close to a light emitting element having an irradiance of (Ee) = 0.1 W · cm ^{−2 to} 1000 W · cm ⁻² The light emitting device can be made to have the property.

  The cerium-activated YAG-based phosphor used in this embodiment and capable of emitting green light has a garnet structure and is resistant to heat, light, and moisture, and the peak wavelength of the excitation absorption spectrum is in the vicinity of 420 nm to 470 nm. Can be made. Also, the emission peak wavelength λp is near 510 nm, and has a broad emission spectrum that extends to the vicinity of 700 nm. On the other hand, the YAG phosphor that emits red light, which is an yttrium-aluminum oxide phosphor activated by cerium, has a garnet structure, is resistant to heat, light and moisture, and has a peak wavelength of 420 nm in the excitation absorption spectrum. To about 470 nm. Further, the emission peak wavelength λp is in the vicinity of 600 nm, and has a broad emission spectrum that extends to the vicinity of 750 nm.

  Of the composition of YAG phosphors with a garnet structure, the emission spectrum is shifted to the short wavelength side by substituting part of Al with Ga, and part of Y of the composition is replaced with Gd and / or La. By doing so, the emission spectrum shifts to the long wavelength side. In this way, it is possible to continuously adjust the emission color by changing the composition. Therefore, an ideal condition for converting white light emission by using blue light emission of the nitride semiconductor is provided such that the intensity on the long wavelength side is continuously changed by the composition ratio of Gd. If the substitution of Y is less than 20%, the green component is large and the red component is small, and if it is 80% or more, the redness component is increased but the luminance is drastically decreased. Similarly, the excitation absorption spectrum is shifted to the short wavelength side by substituting part of Al with Ga in the composition of the YAG phosphor having a garnet structure. By substituting a part of Gd and / or La, the excitation absorption spectrum is shifted to the longer wavelength side. The peak wavelength of the excitation absorption spectrum of the YAG phosphor is preferably on the shorter wavelength side than the peak wavelength of the emission spectrum of the light emitting element. With this configuration, when the current input to the light emitting element is increased, the peak wavelength of the excitation absorption spectrum substantially matches the peak wavelength of the emission spectrum of the light emitting element, so that the excitation efficiency of the phosphor is not reduced. Thus, a light emitting device in which the occurrence of chromaticity deviation is suppressed can be formed.

  The aluminum garnet phosphor can be manufactured by the following method. First, phosphors use oxides or compounds that easily become oxides at high temperatures as raw materials for Y, Gd, Ce, La, Al, Sm, Pr, Tb and Ga, and they are added in a stoichiometric ratio. Mix thoroughly to obtain the raw material. Or a coprecipitated oxide obtained by calcining a solution obtained by coprecipitation of oxalic acid with a solution obtained by dissolving a rare earth element of Y, Gd, Ce, La, Sm, Pr, and Tb in an acid at a stoichiometric ratio with acid; Aluminum and gallium oxide are mixed to obtain a mixed raw material. An appropriate amount of fluoride such as ammonium fluoride is mixed with this as a flux and packed in a crucible, fired in air at a temperature range of 1350 to 1450 ° C. for 2 to 5 hours to obtain a fired product, and then the fired product in water. It can be obtained by ball milling, washing, separating, drying and finally passing through a sieve. In another embodiment of the method for producing a phosphor, in a reducing atmosphere, a first firing step in which a mixture composed of a mixture of phosphor materials and a mixture consisting of a flux is performed in air or in a weak reducing atmosphere. It is preferable to perform baking in two stages, which includes a second baking step to be performed. Here, the weak reducing atmosphere refers to a weak reducing atmosphere set to include at least the amount of oxygen necessary in the reaction process of forming a desired phosphor from the mixed raw material. By performing the first firing step until the formation of the phosphor structure is completed, blackening of the phosphor can be prevented and a decrease in light absorption efficiency can be prevented. In addition, the reducing atmosphere in the second firing step refers to a reducing atmosphere stronger than the weak reducing atmosphere. By firing in two stages in this way, a phosphor with high absorption efficiency at the excitation wavelength can be obtained. Therefore, when a light emitting device is formed with the phosphor thus formed, the amount of the phosphor necessary for obtaining a desired color tone can be reduced, and a light emitting device with high light extraction efficiency can be formed. Can do.

  Aluminum garnet phosphors activated with two or more types of cerium having different compositions may be used in combination, or may be arranged independently. When the phosphors are arranged independently, it is preferable to arrange the phosphors in the order of the phosphor that easily absorbs and emits light from the light emitting element on the shorter wavelength side, and the phosphor that easily absorbs and emits light on the longer wavelength side. This makes it possible to efficiently absorb and emit light.

(Nitride phosphor)
The phosphor used in the present invention contains N and at least one element selected from Be, Mg, Ca, Sr, Ba, and Zn, and C, Si, Ge, Sn, Ti, Zr, and A nitride-based phosphor containing at least one element selected from Hf and activated by at least one element selected from rare earth elements can also be used. Further, the nitride-based phosphor used in the present embodiment refers to a phosphor that emits light when excited by absorbing visible light, ultraviolet light, and light emitted from the YAG-based phosphor emitted from the light-emitting element. For example, Ca—Ge—N: Eu, Z system, Sr—Ge—N: Eu, Z system, Sr—Ca—Ge—N: Eu, Z system, Ca—Ge—O—N: Eu, Z system, Sr—Ge—O—N: Eu, Z system, Sr—Ca—Ge—ON: Eu, Z system, Ba—Si—N: Eu, Z system, Sr—Ba—Si—N: Eu, Z Type, Ba-Si-ON: Eu, Z type, Sr-Ba-Si-ON: Eu, Z type, Ca-Si-CN: Eu, Z type, Sr-Si-CN : Eu, Z system, Sr-Ca-Si-CN: Eu, Z system, Ca-Si-C-O-N: Eu, Z system, Sr-Si-C-O-N: Eu, Z system Sr—Ca—Si—C—O—N: Eu, Z series, Mg—Si—N: Eu, Z series, Mg—Ca—Sr—Si—N: Eu, Z series, Sr—Mg—Si— N: Eu, Z-based, Mg-Si-O- : Eu, Z series, Mg-Ca-Sr-Si-ON: Eu, Z series, Sr-Mg-Si-ON: Eu, Z series, Ca-Zn-Si-CN: Eu, Z-based, Sr-Zn-Si-CN: Eu, Z-based, Sr-Ca-Zn-Si-CN: Eu, Z-based, Ca-Zn-Si-CN- Eu: Z System, Sr—Zn—Si—C—O—N: Eu, Z system, Sr—Ca—Zn—Si—C—O—N: Eu, Z system, Mg—Zn—Si—N: Eu, Z system Mg-Ca-Zn-Sr-Si-N: Eu, Z system, Sr-Zn-Mg-Si-N: Eu, Z system, Mg-Zn-Si-O-N: Eu, Z system, Mg- Ca-Zn-Sr-Si-ON: Eu, Z system, Sr-Mg-Zn-Si-ON: Eu, Z system, Ca-Zn-Si-Sn-CN: Eu, Z system , Sr-Zn-Si-S -CN: Eu, Z system, Sr-Ca-Zn-Si-Sn-CN: Eu, Z system, Ca-Zn-Si-Sn-C-O-N: Eu, Z system, Sr- Zn—Si—Sn—C—O—N: Eu, Z series, Sr—Ca—Zn—Si—Sn—C—O—N: Eu, Z series, Mg—Zn—Si—Sn—N: Eu, Z-based, Mg-Ca-Zn-Sr-Si-Sn-N: Eu, Z-based, Sr-Zn-Mg-Si-Sn-N: Eu, Z-based, Mg-Zn-Si-Sn-O-N : Eu, Z series, Mg-Ca-Zn-Sr-Si-Sn-ON: Eu, Z series, Sr-Mg-Zn-Si-Sn-ON: Various combinations such as Eu, Z series A phosphor can be manufactured. Z indicating that it is a rare earth element preferably contains at least one of Y, La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Er, and Lu, but Sc, Sm , Tm, Yb may be contained. These rare earth elements are mixed in the raw material in the state of oxide, imide, amide, etc. in addition to simple substances. Rare earth elements mainly have a stable trivalent electron configuration, while Yb, Sm, etc. have a divalent configuration, and Ce, Pr, Tb, etc. have a tetravalent electron configuration. When the rare earth element of the oxide is used, the involvement of oxygen affects the light emission characteristics of the phosphor. In other words, the emission luminance may be reduced by containing oxygen. On the other hand, there are also advantages such as shortening the afterglow. However, when Mn is used, the particle size can be increased, and the luminance can be improved.

For example, La is used as a coactivator. Since lanthanum oxide (La ₂ O ₃ ) is a white crystal and is quickly replaced with carbonate when left in the air, it is stored in an inert gas atmosphere.
For example, Pr is used as a coactivator. Praseodymium oxide (Pr ₆ O ₁₁ ) is a non-stoichiometric oxide, unlike ordinary rare earth oxide Z ₂ O _3, and burns praseodymium oxalate, hydroxide, carbonate, etc. in the air 800 When heated to 0 ° C., it is obtained as a black powder having a composition of Pr ₆ O ₁₁ . Pr ₆ O ₁₁ is a starting material for synthesizing a praseodymium compound, and a high-purity one is also commercially available.

In particular, the phosphor according to the present invention includes Mn-added Sr—Ca—Si—N: Eu, Ca—Si—N: Eu, Sr—Si—N: Eu, Sr—Ca—Si—O—N: Eu, Ca-Si-ON: Eu, Sr-Si-ON: Eu-based silicon nitride. The basic constituent elements of this phosphor are represented by the general formula L _X Si _Y N _{(2 / 3X + 4 / 3Y)} : Eu or L _X Si _Y O _Z N _{(2 / 3X + 4 / 3Y-2 / 3Z)} : Eu (L is Sr, Ca, or any one of Sr and Ca.) In the general formula, X and Y are preferably X = 2, Y = 5, or X = 1, Y = 7, but any can be used. Specifically, the basic constituent elements, Mn is added _{(Sr X Ca 1-X)} 2 Si 5 N 8: Eu, Sr 2 Si 5 N 8: Eu, Ca 2 Si 5 N 8: Eu, Sr _{X Ca 1-X Si 7 N} 10: Eu, SrSi 7 N 10: Eu, CaSi 7 N 10: it is preferable to use a phosphor represented by Eu, during the composition of the phosphor, Mg, At least one selected from the group consisting of Sr, Ca, Ba, Zn, B, Al, Cu, Mn, Cr and Ni may be contained. However, the present invention is not limited to this embodiment and examples.
L is any one of Sr, Ca, Sr and Ca. The mixing ratio of Sr and Ca can be changed as desired.
By using Si for the composition of the phosphor, it is possible to provide an inexpensive phosphor with good crystallinity.

Europium Eu, which is a rare earth element, is used for the emission center. Europium mainly has bivalent and trivalent energy levels. The phosphor of the present invention uses Eu ²⁺ as an activator with respect to the base alkaline earth metal silicon nitride. Eu ²⁺ is easily oxidized and is commercially available with a trivalent Eu ₂ O ₃ composition. However, in commercially available Eu ₂ O ₃ , O is greatly involved and it is difficult to obtain a good phosphor. Therefore, it is preferable to use a material obtained by removing O from Eu ₂ O ₃ out of the system. For example, it is preferable to use europium alone or europium nitride. However, this is not the case when Mn is added.

_{Sr 2 Si 5 N 8: Eu} , Pr, Ba 2 Si 5 N 8: Eu, Pr, Mg 2 Si 5 N 8: Eu, Pr, Zn 2 Si 5 N 8: Eu, Pr, SrSi 7 N 10: Eu _{, Pr, BaSi 7 N 10:} Eu, Ce, MgSi 7 N 10: Eu, Ce, ZnSi 7 N 10: Eu, Ce, Sr 2 Ge 5 N 8: Eu, Ce, Ba 2 Ge 5 N 8: Eu, _{Pr, Mg 2 Ge 5 N 8} : Eu, Pr, Zn 2 Ge 5 N 8: Eu, Pr, SrGe 7 N 10: Eu, Ce, BaGe 7 N 10: Eu, Pr, MgGe 7 N 10: Eu, Pr _{, ZnGe 7 N 10: Eu,} Ce, Sr 1.8 Ca 0.2 Si 5 N 8: Eu, Pr, Ba 1.8 Ca 0.2 Si 5 N 8: Eu, Ce, Mg 1.8 Ca 0 _.2 Si ₅ N ₈ : Eu, Pr, Zn _1.8 Ca _0.2 Si ₅ N ₈ : Eu, Ce, Sr _0.8 Ca _0.2 Si ₇ N ₁₀ : Eu, La, Ba _0.8 Ca _0.2 Si ₇ N _{10: Eu, La, Mg 0.8} Ca 0.2 Si 7 N 10: Eu, Nd, Zn 0.8 Ca 0.2 Si 7 N 10: Eu, Nd, Sr 0.8 Ca 0.2 Ge 7 _{N 10: Eu, Tb, Ba} 0.8 Ca 0.2 Ge 7 N 10: Eu, Tb, Mg 0.8 Ca 0.2 Ge 7 N 10: Eu, Pr, Zn 0.8 Ca 0.2 Ge ₇ N ₁₀ : Eu, Pr, Sr _0.8 Ca _0.2 Si ₆ GeN ₁₀ : Eu, Pr, Ba _0.8 Ca _0.2 Si ₆ GeN ₁₀ : Eu, Pr, Mg _0.8 Ca _{0.2 Si 6 GeN 10: Eu, Y} , Zn 0.8 Ca 0.2 Si _{GeN 10: Eu, Y, Sr} 2 Si 5 N 8: Pr, Ba 2 Si 5 N 8: Pr, Sr 2 Si 5 N 8: Tb, BaGe 7 N 10: Ce , etc. can be manufactured without limitation.

Mn as an additive promotes diffusion of Eu ²⁺ and improves luminous efficiency such as luminous luminance, energy efficiency, and quantum efficiency. Mn is contained in the raw material, or Mn alone or a Mn compound is contained in the manufacturing process and fired together with the raw material. However, Mn is not contained in the basic constituent elements after firing, or even if contained, only a small amount remains compared to the initial content. This is probably because Mn was scattered in the firing step.
The phosphor includes Mg, Ga, In, Li, Na, K, Re, Mo, Fe, Sr, Ca, Ba, Zn, B, Al, Cu, in the basic constituent element or together with the basic constituent element. It contains at least one selected from the group consisting of Mn, Cr, O and Ni. These elements have actions such as increasing the particle diameter and increasing the luminance of light emission. Further, B, Al, Mg, Cr and Ni have an effect that afterglow can be suppressed.

  Such a nitride-based phosphor absorbs part of the blue light emitted by the light emitting element and emits light in the yellow to red region. Using a nitride-based phosphor together with a YAG-based phosphor in the light-emitting device having the above-described configuration, the blue light emitted from the light-emitting element and the yellow to red light by the nitride-based phosphor are mixed to produce a warm color system. Provided is a light-emitting device that emits white mixed-color light. It is preferable that the phosphor added in addition to the nitride-based phosphor contains an yttrium / aluminum oxide phosphor activated with cerium. This is because it can be adjusted to a desired chromaticity by containing the yttrium aluminum oxide phosphor. The yttrium / aluminum oxide phosphor activated with cerium absorbs part of the blue light emitted by the light emitting element and emits light in the yellow region. Here, the blue light emitted from the light emitting element and the yellow light of the yttrium / aluminum oxide fluorescent material emit light blue-white by mixing colors. Therefore, the yttrium / aluminum oxide phosphor and the phosphor emitting red light are mixed together in a light-transmitting wavelength conversion member and combined with the blue light emitted by the light emitting element to produce a white-based material. A light emitting device that emits mixed color light can be provided. Particularly preferred is a white light emitting device whose chromaticity is located on the locus of black body radiation in the chromaticity diagram. However, in order to provide a light emitting device having a desired color temperature, the amount of phosphor of the yttrium / aluminum oxide phosphor and the amount of phosphor of red light emission can be appropriately changed. This light-emitting device that emits white-based mixed color light improves the special color rendering index R9. A conventional white light emitting device consisting only of a combination of a blue light emitting element and an yttrium aluminum oxide phosphor activated with cerium has a special color rendering index R9 of almost 0 at a color temperature of Tcp = 4600K, and a reddish component. Was lacking. For this reason, increasing the special color rendering index R9 has been a problem to be solved. However, in the present invention, the special color rendering index near the color temperature Tcp = 4600K is obtained by using the phosphor emitting red light together with the yttrium aluminum oxide phosphor. R9 can be increased to around 40.

Next, the phosphor according to the present invention: is described a method of manufacturing the _{((Sr X Ca 1-X} ) 2 Si 5 N 8 Eu), but is not limited to this manufacturing method. The phosphor contains Mn and O.

Raw materials Sr and Ca are pulverized. The raw materials Sr and Ca are preferably used alone, but compounds such as imide compounds and amide compounds can also be used. The raw materials Sr and Ca may contain B, Al, Cu, Mg, Mn, MnO, Mn ₂ O ₃ , Al ₂ O ₃ and the like. The raw materials Sr and Ca are pulverized in a glove box in an argon atmosphere. Sr and Ca obtained by pulverization preferably have an average particle diameter of about 0.1 μm to 15 μm, but are not limited to this range. The purity of Sr and Ca is preferably 2N or higher, but is not limited thereto. In order to improve the mixed state, at least one of the metal Ca, the metal Sr, and the metal Eu can be alloyed, nitrided, pulverized, and used as a raw material.

The raw material Si is pulverized. The raw material Si is preferably a simple substance, but a nitride compound, an imide compound, an amide compound, or the like can also be used. For example, Si ₃ N ₄ , Si (NH ₂ ) ₂ , Mg ₂ Si, or the like. The purity of the raw material Si is preferably 3N or more, but Al ₂ O ₃ , Mg, metal borides (Co ₃ B, Ni ₃ B, CrB), manganese oxide, H ₃ BO ₃ , B ₂ O ₃ , Compounds such as Cu ₂ O and CuO may be contained. Si is also pulverized in a glove box in an argon atmosphere or a nitrogen atmosphere in the same manner as the raw materials Sr and Ca. The average particle size of the Si compound is preferably about 0.1 μm to 15 μm.

  Next, the raw materials Sr and Ca are nitrided in a nitrogen atmosphere. This reaction formula is shown in the following formula 1 and formula 2, respectively.

3Sr + N ₂ → Sr ₃ N ₂ (Formula 1)
3Ca + N ₂ → Ca ₃ N ₂ (Formula 2)
Sr and Ca are nitrided in a nitrogen atmosphere at 600 to 900 ° C. for about 5 hours. Sr and Ca may be mixed and nitrided, or may be individually nitrided. Thereby, a nitride of Sr and Ca can be obtained. Sr and Ca nitrides are preferably of high purity, but commercially available ones can also be used.

  The raw material Si is nitrided in a nitrogen atmosphere. This reaction formula is shown in the following formula 3.

3Si + 2N ₂ → Si ₃ N ₄ (Formula 3)
Silicon Si is also nitrided in a nitrogen atmosphere at 800 to 1200 ° C. for about 5 hours. Thereby, silicon nitride is obtained. The silicon nitride used in the present invention is preferably highly pure, but commercially available ones can also be used.

Sr, Ca or Sr—Ca nitride is pulverized. Sr, Ca, and Sr—Ca nitrides are pulverized in a glove box in an argon atmosphere or a nitrogen atmosphere.
Similarly, Si nitride is pulverized. Similarly, the Eu compound Eu ₂ O ₃ is pulverized. Europium oxide is used as the Eu compound, but metal europium, europium nitride, and the like can also be used. In addition, as the raw material Z, an imide compound or an amide compound can be used. Europium oxide is preferably highly purified, but commercially available products can also be used. The average particle size of the alkaline earth metal nitride, silicon nitride and europium oxide after pulverization is preferably about 0.1 μm to 15 μm.

The raw material may contain at least one selected from the group consisting of Mg, Sr, Ca, Ba, Zn, B, Al, Cu, Mn, Cr, O, and Ni. In addition, the above elements such as Mg, Zn, and B can be mixed by adjusting the blending amount in the following mixing step. These compounds can be added alone to the raw material, but are usually added in the form of compounds. Such compounds include H ₃ BO ₃ , Cu ₂ O ₃ , MgCl ₂ , MgO · CaO, Al ₂ O ₃ , metal borides (CrB, Mg ₃ B ₂ , AlB ₂ , MnB), B ₂ O ₃ , Cu ₂ O, CuO, and the like.

After the pulverization, Sr, Ca, Sr—Ca nitride, Si nitride, and Eu compound Eu ₂ O ₃ are mixed, and Mn is added. Since these mixtures are easily oxidized, they are mixed in a glove box in an Ar atmosphere or a nitrogen atmosphere.

Finally, a mixture of Sr, Ca, Sr—Ca nitride, Si nitride, and Eu compound Eu ₂ O ₃ is fired in an ammonia atmosphere. A phosphor represented by (Sr _X Ca _1-X ) ₂ Si ₅ N ₈ : Eu to which Mn is added can be obtained by firing. However, the composition of the target phosphor can be changed by changing the blending ratio of each raw material.

For firing, a tubular furnace, a small furnace, a high-frequency furnace, a metal furnace, or the like can be used. The firing temperature can be in the range of 1200 to 1700 ° C, but the firing temperature is preferably 1400 to 1700 ° C. It is preferable to use a one-step baking in which the temperature is gradually raised and the baking is performed at 1200 to 1500 ° C. for several hours, but the first baking is performed at 800 to 1000 ° C. and the heating is gradually started from 1200. Two-stage firing (multi-stage firing) in which the second stage firing is performed at 1500 ° C. can also be used. The phosphor material is preferably fired using a boron nitride (BN) crucible or boat. Besides the crucible made of boron nitride, a crucible made of alumina (Al ₂ O ₃ ) can also be used.

  By using the above manufacturing method, it is possible to obtain a target phosphor.

In the embodiment of the present invention, a nitride-based phosphor is used as the phosphor that emits reddish light. In the present invention, the above-described YAG-based phosphor can emit red light. It is also possible to provide a light emitting device including a simple phosphor. Such a phosphor capable of emitting red light is a phosphor that emits light when excited by light having a wavelength of 400 to 600 nm. For example, Y ₂ O ₂ S: Eu, La ₂ O ₂ S: Eu. CaS: Eu, SrS: Eu, ZnS: Mn, ZnCdS: Ag, Al, ZnCdS: Cu, Al and the like. Thus, by using a phosphor capable of emitting red light together with a YAG phosphor, it is possible to improve the color rendering properties of the light emitting device.

  The phosphors capable of emitting red light typified by the aluminum garnet-based phosphor and nitride-based phosphor formed as described above are included in two wavelength conversion members in the vicinity of the light-emitting element. One or more types may be present, or one type or two or more types may be present in the two-layer wavelength conversion member. With such a configuration, it is possible to obtain mixed color light by mixing light from different types of phosphors. In this case, it is preferable that the average particle diameters and shapes of the phosphors are similar in order to better mix the light emitted from the phosphors and reduce color unevenness. Also, considering that the nitride-based phosphor absorbs part of the light that has been wavelength-converted by the YAG-based phosphor, the nitride-based phosphor is disposed closer to the light emitting element than the YAG-based phosphor. It is preferable to form the wavelength conversion member as described above. With this configuration, a part of the light wavelength-converted by the YAG phosphor is not absorbed by the nitride phosphor, and the YAG phosphor and the nitride phosphor are mixed. Compared with the case where it contains, the color rendering property of mixed-color light can be improved.

(Alkaline earth metal silicate)
The light-emitting device in this embodiment mode uses alkaline earth activated by europium as a phosphor that absorbs part of light emitted from a light-emitting element and emits light having a wavelength different from the wavelength of the absorbed light. It can also have a metal silicate. The alkaline earth metal silicate can be a light-emitting device that emits warm color mixed light using blue light as excitation light. The alkaline earth metal silicate is preferably an alkaline earth metal orthosilicate represented by the following general formula.
(2-x-y) SrO · x (Ba, Ca) O · (1-a-b-c-d) SiO 2 · aP 2 O 5 bAl 2 O 3 cB 2 O 3 dGeO 2: yEu 2+ ( Equation Medium, 0 <x <1.6, 0.005 <y <0.5, 0 <a, b, c, d <0.5.)
(2-x-y) BaO · x (Sr, Ca) O · (1-a-b-c-d) SiO 2 · aP 2 O 5 bAl 2 O 3 cB 2 O 3 dGeO 2: yEu 2+ ( Equation (Inside, 0.01 <x <1.6, 0.005 <y <0.5, 0 <a, b, c, d <0.5.)
Here, preferably, at least one of the values of a, b, c and d is greater than 0.01.

The light-emitting device in the present embodiment is a phosphor composed of an alkaline earth metal salt. In addition to the alkaline earth metal silicate described above, alkaline earth metal aluminate or Y activated by europium and / or manganese is used. (V, P, Si) O ₄ : Eu, or an alkaline earth metal-magnesium-disilicate represented by the following formula:

Me (3-xy) MgSi ₂ O ₃ : xEu, yMn (wherein 0.005 <x <0.5, 0.005 <y <0.5, Me represents Ba and / or Sr and / or Or Ca.)
Next, the manufacturing process of the phosphor made of alkaline earth metal silicate in the present embodiment will be described.

  For the production of alkaline earth metal silicates, the stoichiometric amounts of the starting materials alkaline earth metal carbonate, silicon dioxide and europium oxide are intimately mixed according to the selected composition, and the phosphor is produced. In a conventional solid reaction, the desired phosphor is converted at a temperature of 1100 ° C. and 1400 ° C. under a reducing atmosphere. At this time, it is preferable to add less than 0.2 mol of ammonium chloride or other halide. If necessary, part of silicon can be replaced with germanium, boron, aluminum, and phosphorus, and part of europium can be replaced with manganese.

One of the phosphors as described above, ie, alkaline earth metal aluminates activated with europium and / or manganese, Y (V, P, Si) O ₄ : Eu, Y ₂ O ₂ S: Eu ³⁺ By combining one or these phosphors, as shown in the following Table 1 as an example, an emission color having a desired color temperature and high color reproducibility can be obtained.

(Alkaline earth metal halogen apatite fluorescent substance)
In addition, an element represented by M including at least one selected from Mg, Ca, Ba, Sr, and Zn, and an M ′ including at least one selected from Mn, Fe, Cr, and Sn are represented. An alkaline earth metal halogen apatite fluorescent material activated by Eu having an element can be used, and a light emitting device capable of emitting a white light system with high productivity and high luminance can be obtained. In particular, an alkaline earth metal halogen apatite fluorescent material activated with Eu containing at least Mn and / or Cl is excellent in light resistance and environmental resistance. In addition, the emission spectrum emitted from the nitride semiconductor can be efficiently absorbed. Further, the white region can emit light, and the region can be adjusted by the composition. Further, it can emit yellow and red light with high brightness by absorbing the ultraviolet region of a long wavelength. Therefore, a light emitting device with excellent color rendering can be obtained. Needless to say, alkaline earth metal chloroapatite fluorescent materials are included as examples of alkaline earth metal halogen apatite fluorescent materials. In the alkaline earth metal halogen apatite fluorescent material, when the general formula is represented by (M _1-xy Eu _x M ′ _y ) ₁₀ (PO ₄ ) ₆ Q ₂ (where M is Mg, Ca, Ba) , Sr, Zn, M ′ is at least one selected from Mn, Fe, Cr, Sn, Q is at least one selected from halogen elements F, Cl, Br, and I 0.0001 ≦ x ≦ 0.5 and 0.0001 ≦ y ≦ 0.5.), A light emitting device capable of emitting mixed color light with high productivity is obtained.

Further, in addition to the alkaline earth metal halogen apatite fluorescent material, BaMg ₂ Al ₁₆ O ₂₇ : Eu, (Sr, Ca, Ba) ₅ (PO ₄ ) ₃ Cl: Eu, SrAl ₂ O ₄ : Eu, ZnS: Cu _{, Zn 2 GeO 4: Mn,} BaMg 2 Al 16 O 27: Eu, Mn, Zn 2 GeO 4: Mn, Y 2 O 2 S: Eu, La 2 O 2 S: Eu, Gd 2 O 2 S: Eu, When at least one selected fluorescent material is contained, more detailed color tone can be adjusted, and white light with high color rendering can be obtained with a relatively simple configuration. Furthermore, the above-mentioned fluorescent substance can contain Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni, Ti, Pr, etc. in addition to Eu as desired.

(Other phosphors)
In this embodiment, a phosphor that is excited by ultraviolet light and generates light of a predetermined color can be used as a phosphor. As a specific example, for example,
(1) Ca ₁₀ (PO ₄ ) ₆ FCl: Sb, Mn
(2) M ₅ (PO ₄ ) ₃ Cl: Eu (where M is at least one selected from Sr, Ca, Ba, Mg)
(3) BaMg ₂ Al ₁₆ O ₂₇ : Eu
(4) BaMg ₂ Al ₁₆ O ₂₇ : Eu, Mn
(5) 3.5MgO.0.5MgF ₂ .GeO ₂ : Mn
(6) Y ₂ O ₂ S: Eu
(7) Mg ₆ As ₂ O ₁₁ : Mn
(8) Sr ₄ Al ₁₄ O ₂₅ : Eu
(9) (Zn, Cd) S: Cu
(10) SrAl ₂ O ₄ : Eu
(11) Ca ₁₀ (PO ₄ ) ₆ ClBr: Mn, Eu
(12) Zn ₂ GeO ₄ : Mn
(13) Gd ₂ O ₂ S: Eu, (14) La ₂ O ₂ S: Eu, and the like.
These phosphors may be used alone in a single wavelength conversion member, or may be used as a mixture. Furthermore, they may be used alone or in combination in a wavelength conversion member in which two or more layers are laminated.

[Step 5: Lead electrode forming]
In this step, each lead electrode portion is cut from the punched metal plate, and the positive lead electrode and the negative lead electrode protruding from the end surface of the package are formed (bent) along the side surface of the package to form a J-bend ( A Bend type positive and negative connection terminal portion is formed. In the present embodiment, the side surface of the package where the lead electrode protrudes is preliminarily formed with an angle more than necessary, and the lead electrode is bent so as to have an obtuse angle with respect to the mounting surface. The lead electrode can be arranged at a desired angle in consideration of the influence of elasticity.

  In the present embodiment, when the positive lead electrode and the negative lead electrode protrude from the short-axis side surface of the package, the protruding portion is preferably bent toward the surface opposite to the light emitting surface. Thus, it can be mounted on the wiring board without adversely affecting the light emitting surface side. In addition, when the positive lead electrode and the negative lead electrode are inserted so as to protrude from the end surface on the major axis side of the package main surface, and the protruding portion is bent toward a surface perpendicular to the light emitting surface, the lead electrode connection terminal The bonding area between the portion and the wiring board can be increased, and the mounting accuracy can be increased. Accordingly, when the light emitting device is temporarily mounted on the wiring board and the reflow process is performed, the light emitting device can be prevented from rising from the temporary mounting surface. When the lead is bent and used as the connection terminal portion in this way, it is preferable that the wall surface of the molding member on the mounting surface side and the exposed surface of the lead electrode are located on substantially the same plane. Note that the structure of the connection terminal portion of the present invention is not limited to the J-bend type, and may be another structure such as a gull wing type. Through the steps as described above, the light-emitting device of this embodiment is manufactured.

[Step 6: Separate light emitting device]
In this step, the hanger lead supporting the package is removed from the package and separated into individual light emitting devices. At this time, the shape of the tip of the hanger lead supporting the package is formed as a recess 112 on the side surface of the package. The recess 112 facilitates positioning with an external member such as a planar light guide plate having a shape that can be fitted to the recess 112.

  Further, when a resin burr is generated by the tip portion of the hanger lead, the light-emitting device is prevented from being thinned by the thickness of the resin burr. On the other hand, the hanger lead in this embodiment is arranged so as to support the package from the side surface direction without generating a resin burr in the thickness direction of the light emitting device, and the light emitting device can be thinned.

[Step 7: Mounting of Light Emitting Device]
The light emitting device according to the embodiment produced as described above is arranged on a mounting substrate in which external electrodes are wired on a substrate, and is electrically and mechanically connected by a conductive member such as solder. Implemented as: The substrate member of the wiring substrate is preferably excellent in thermal conductivity, and an aluminum base substrate, a ceramic base substrate, or the like can be used. In addition, when using a glass epoxy substrate or paper phenol substrate with poor thermal conductivity, it is preferable to take heat dissipation measures such as a thermal pad and a thermal via. Further, the light emitting diode and the wiring board can be electrically connected by a conductive member such as solder. In consideration of heat dissipation, it is preferable to use a silver paste. In the light emitting device of the present invention, a rigid translucent optical member such as a lens or a light guide plate can be provided on the light emitting surface side with high accuracy. The light guide plate according to the present embodiment has a notch that individually introduces light from a plurality of light sources. The inner wall of the notch has at least a first plane that contacts the light emitting surface of the light emitting device of the present invention, and a second plane that contacts the first plane and the second main surface of the package. Thus, by providing positioning with the light guide plate in the molding member that can be substantially constant at all times, a planar light source can be formed with high yield.

  The material of the light guide plate is preferably excellent in light transmittance and moldability, and organic members such as acrylic resin, polycarbonate resin, amorphous polyolefin resin, and polystyrene resin, and inorganic members such as glass can be used. . The surface of the light guide plate preferably has a surface accuracy Ra of 25 μm (see JIS standard) or less in order to improve the transmittance and the total reflected light rate.

  Such a light guide plate is mounted so that each light emitting device and each notch portion face each other. The light guide plate mounting method can be selected according to the specifications and requirements, such as screwing, bonding, welding, etc., which can be easily positioned and can ensure the bonding strength. Further, the planar light source of the present invention can be provided with a diffusion sheet on the upper side. Thus, the planar light source of the present invention can also be used as a direct backlight light source that irradiates other members such as a diffusion sheet disposed above. The selection of the diffusion sheet affects the film thickness and performance of the light guide plate. Therefore, it is preferable to verify and select each time according to specifications and requirements. In this example, a diffusion sheet having a haze value of 88% to 90% (see JIS standard) and a film thickness of about 100 μm is used for a light guide plate made of polycarbonate having excellent heat resistance and a film thickness of 20 mm. Thereby, the space | interval of the dot of each light source is relaxed more, and uniform light emission is obtained. Such a diffusion sheet can be attached to the light guide plate directly by adhesion or welding. When a cover lens is provided above, it can be fixed by being sandwiched between the cover lens and the light guide plate. The distance between the diffusion sheet and the light guide plate is preferably 0 mm to 10 mm, and most preferably these interfaces are in close contact. The material of the diffusion sheet is mainly PET, but is not particularly limited as long as it is a material that does not deform or deteriorate due to the heat generated by the light emitting diode.

  The planar light source obtained in this way can obtain uniform and high-luminance light emission over the entire light emitting surface.

  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 schematic front view of a surface-mount (SMD) type light emitting device 100 according to the present embodiment as viewed from the light emission observation surface side (that is, the main surface direction of the package 106). A surface-mount (SMD) type light emitting device 100 as shown in FIG. 1 includes an LED chip 107 and one main surface of a lead electrode 105 on which the LED chip 107 is mounted. And a package 106 having a portion exposed from the bottom surface of the opening. Further, the opening has a protrusion (111), and the inner wall surface of the opening is a pair of inner wall surfaces (101a) extending in the major axis direction of the main surface of the package 106 and facing each other extending in the minor axis direction. The inner wall surface (102), the inner wall surface (101b) facing the inner wall surface (101a) extending in the long axis direction, and the inner wall surface (101c) facing the inner wall surface (101a) and provided on the protruding portion (111) And an inner wall surface (104) continuously provided at a predetermined angle from the inner wall surface (101b) to the inner wall surface (101c). More specifically, the opening on the main surface of the package 106 is provided substantially perpendicular to the mounting surface between the light emitting device 100 and an external support substrate provided with a conductive pattern, and the light emitting device is in a direction substantially parallel to the mounting surface. The light from the light emitting element is emitted. Further, the package 106 has a protruding portion (111) in which a part of the opening protrudes in the mounting surface direction, and the inner wall surfaces included in the protruding portion are a pair of inner wall surfaces 104 and 101c that face each other. Here, the protrusion (111) is shown as a shaded region in a part of the opening in FIG. The main surface of the lead electrode 105 extends on the bottom surface of the protruding portion (111), and a part of the LED chip 107 is placed thereon. Further, as shown in FIG. 3 which is a side view of the light emitting device according to the present embodiment, the mounting surface side surface of the lead electrode 103 protruding from the outer wall surface of the package 106 forms the protruding portion (111). It is bent in the direction of the main surface of the package so as to be substantially flush with the outer wall surface facing the inner wall surface 101c. Further, the end portion of the lead electrode 103 is bent along the outer wall surface of the package in the direction opposite to the mounting surface. By arranging the lead electrode 103 in this manner, a light emitting device that can be reduced in size as compared with the conventional one can be obtained, and can be stably mounted on an external substrate.

In the LED chip according to this example, a nitride semiconductor element having a 475 nm In _0.2 Ga _0.8 N semiconductor having a monochromatic emission peak of visible light is used as a light emitting layer. More specifically, in the LED chip, TMG (trimethyl gallium) gas, TMI (trimethyl indium) gas, nitrogen gas and dopant gas are flowed together with a carrier gas on a cleaned sapphire substrate, and a nitride semiconductor is formed by MOCVD. It can be formed by forming a film. A layer to be an n-type nitride semiconductor or a p-type nitride semiconductor is formed by switching between SiH ₄ and Cp ₂ Mg as the dopant gas.

As an element structure of the LED chip, an n-type GaN layer which is an undoped nitride semiconductor on a sapphire substrate, a GaN layer where an Si-doped n-type electrode is formed to become an n-type contact layer, and an n-type nitride semiconductor which is an undoped nitride semiconductor 5 layers of InGaN layers sandwiched between GaN layers, each comprising a type GaN layer, a GaN layer that constitutes a light emitting layer, a InGaN layer that constitutes a well layer, and a GaN layer that constitutes a barrier layer It is a multiple quantum well structure. On the light emitting layer, an AlGaN layer as a p-type cladding layer doped with Mg and a GaN layer as a p-type contact layer doped with Mg are sequentially laminated. (Note that a GaN layer is formed on the sapphire substrate at a low temperature to serve as a buffer layer. The p-type semiconductor is annealed at 400 ° C. or higher after film formation.)
Etching exposes the surface of each pn contact layer on the same side as the nitride semiconductor on the sapphire substrate. Positive and negative pedestal electrodes including W / Pt / Au are formed on each contact layer by sputtering. A metal thin film is formed on the entire surface of the p-type nitride semiconductor as a translucent electrode, and then a pedestal electrode is formed on a part of the translucent electrode. Further, the p-side pedestal electrode has an auxiliary electrode that extends in an arc shape from the position where the conductive wire or the bump is disposed toward the adjacent outer edge of the LED chip. Such an auxiliary electrode diffuses the current input to the semiconductor light emitting element throughout the translucent electrode. After a scribe line is drawn on the completed semiconductor wafer, it is divided by an external force to form an LED chip (light refractive index 2.1) which is a semiconductor light emitting element.

  Next, a molten polyphthalamide resin is poured and cured from a gate corresponding to the lower surface facing the main surface of the package into a mold in which a pair of positive and negative lead electrodes are inserted and closed, 1 is formed. The package has an opening in which the light emitting element can be accommodated, and the positive and negative lead electrodes are integrally formed so that one main surface is exposed from the bottom of the opening. Inner wall surfaces 101a, 101b, 101c, an inner wall surface 102, and an inner wall surface 104 are formed on the inner wall surface of the opening. Further, a part of the outer wall surface of the package has a step 110. Further, the outer lead portions of the positive and negative lead electrodes exposed from the side surface of the package are bent inward at both ends of the surface opposite to the light emitting surface.

  The LED chip is die-bonded with an epoxy resin so that a part of the LED chip protrudes from the protruding portion 111 with respect to the bottom surface of the opening thus formed. Here, the bonding member used for die bonding is not particularly limited, and an Au—Sn alloy or a resin or glass containing a conductive material can be used. The conductive material contained is preferably Ag. When an Ag paste having a content of 80% to 90% is used, a light emitting device having excellent heat dissipation and low stress after bonding can be obtained. Next, the respective electrodes of the die-bonded LED chip and the respective lead electrodes exposed from the bottom surface of the package opening are electrically connected by Au wires.

  Next, light calcium carbonate (refractive index of 1.62) having an average particle size of 1.0 μm and an oil absorption of 70 ml / 100 g as a diffusing agent with respect to 100 wt% of phenylmethyl silicone resin composition (refractive index of 1.53). 3 wt%, and stirring is performed for 5 minutes with a rotation and revolution mixer. Next, in order to cool the heat generated by the stirring treatment, the resin is allowed to stand for 30 minutes to return to a constant temperature and stabilized.

  The curable composition thus obtained is filled in the package opening up to the same plane line as the upper surface of both ends of the opening. Finally, heat treatment is performed at 70 ° C. × 3 hours and 150 ° C. × 1 hour. Thereby, the light emission surface which has a substantially parabolic dent from the upper surface of the both ends of an opening part to a center part is obtained. Moreover, the sealing member which consists of hardened | cured material of a curable composition has the 1st layer with much content of a diffusing agent, and the 2nd layer with little content of a diffusing agent or not contained than a 1st layer. The surface of the LED chip is covered with a first layer. Thereby, the light emitted from the LED chip can be efficiently extracted to the outside, and good light uniformity can be obtained. The first layer is preferably formed continuously from the bottom surface of the opening to the surface of the LED chip, whereby the shape of the light emitting surface can be a smooth opening.

  The light emitting device according to the present embodiment has the inner wall surface 104 in the opening of the package, so that light emitted from the light emitting element can be emitted from the inside of the opening toward the light emission observation surface without waste. In this way, light can be incident in a wide range with respect to the light incident surface of the light guide plate.

  FIG. 5 is a schematic top view of the light emitting device 200 according to this example. Here, the protrusion (111) is shown as a shaded region in a part of the opening in FIG. The light emitting element 107 according to this example has the same configuration as that of Example 1 except that it has two pairs of positive and negative electrodes. That is, the light emitting element 107 according to the present example is formed to include two LED chips described in the first example. Such a light-emitting element 107 has two LED chips described in Example 1 mounted adjacent to each other, or a scribe line is drawn on a completed semiconductor wafer so as to have two pairs of positive and negative electrodes. Then, it can be formed by dividing by external force. Further, the pair of positive electrodes of the light emitting element 107 are connected to the same positive lead electrode, while the pair of negative electrodes are connected to the same negative lead electrode via the conductive wires 108 respectively. Yes. Therefore, the light emitting device 200 according to the present embodiment is configured such that the two LED chips described in the first embodiment are connected in parallel to the pair of positive and negative lead electrodes 105.

  In particular, a part of the light emitting element 107 according to the present embodiment is placed on the bottom surface of the protruding portion 111. With this configuration, two side surfaces adjacent to each other among the side surfaces of the light emitting element 107 are close to and opposed to the inner wall surface 104 of the opening, and light emission from the light emitting element 107 is efficiently performed. Can be reflected in the direction of the emission observation surface. Further, the positive and negative conductive wires 108 are not connected to the lead electrode 105 exposed on the bottom surface of the protruding portion 111 but on the lead electrode 105 exposed on the bottom surface of the opening between the inner wall surface 102 and the light emitting element 107. Wire bonding is performed. Accordingly, light traveling from the light emitting element 107 toward the inner wall surface 104 is incident on the inner wall surface 104 without being blocked by the conductive wire 108 (particularly, the portion of the metal piece placed on the lead electrode). It can be reflected in the direction of the emission observation surface.

  As shown in FIG. 6A, the semiconductor element in this embodiment is a composite element 120 in which the light emitting element 107 is flip-chip mounted on the submount 113. The composite element 120 is housed in the opening of the package, and a part of the submount 113 is placed on the bottom surface of the protrusion 111. Further, the light emitting device is the same as that of the first embodiment except that a part of the light emitting element 107 is located at the protruding portion 111 when viewed from the light emission observation plane direction. Here, in the light emitting element 107, the main surface of the light-transmitting substrate 121 on the side where the semiconductor is not laminated is directed to the light emission observation surface side, and a pair of positive and negative pad electrodes provided on the same surface side of the light emitting element 107 are sub A pair of positive and negative electrodes provided on the mount 113 are opposed to each other and bonded by bumps 118a and 118b. Further, at least one side surface of the light emitting element 107 is opposed to the inner wall surface 104.

  On one main surface of the submount 113, the positive electrode 115a and the negative electrode 115b are insulated from each other by the insulating film 114 by a conductive member. As the conductive member, it is preferable to use a silver-white metal, particularly aluminum, silver, gold, or an alloy thereof having high reflectivity. The material of the submount itself is preferably silicon that can form a protective element that prevents the light emitting element from being destroyed by overvoltage. Alternatively, the material of the submount is preferably a material having substantially the same thermal expansion coefficient as that of the nitride semiconductor light emitting element, such as aluminum nitride. By using such a material, the thermal stress generated between the submount and the light emitting element is relieved, and the electrical connection through the bumps between the submount and the light emitting element is maintained. The reliability of the apparatus can be improved.

  As the protective element, a zener diode that becomes energized when a voltage higher than a specified voltage is applied, a capacitor that absorbs a pulsed voltage, or the like can be used. FIG. 6B shows a circuit diagram when the protective element is a Zener diode. The submount functioning as a Zener diode has a p-type semiconductor region 119a having a positive electrode 115a and an n-type semiconductor region 119b having a negative electrode 115b, and is opposite to the p-side electrode and the n-side electrode of the light emitting element. They are connected in parallel. That is, the n-side pad electrode and the p-side electrode of the light emitting element are electrically and mechanically connected to the positive electrode and the negative electrode provided in the p-type semiconductor region and the n-type semiconductor region of the submount, respectively, by the bumps. Further, both the positive and negative electrodes provided on the submount are connected to the lead electrode 105 by the conductive wire 108. Note that a back electrode 117 having the same polarity as that of either the p-type semiconductor region or the n-type semiconductor region, for example, the p-type semiconductor region is provided on the surface facing the main surface of the submount on which the light emitting element is mounted. The lead electrode 105 can be directly connected without using a conductive wire.

  In this way, by providing the submount with the function of a Zener diode, when an excessive voltage is applied between the electrodes, if the voltage exceeds the Zener voltage of the Zener diode, the Zener diode is connected between the positive and negative electrodes. The voltage is held and never exceeds the zener voltage. Therefore, it is possible to prevent an excessive voltage from being applied between the light emitting elements, protect the light emitting elements from the excessive voltage, and prevent the occurrence of element destruction and performance deterioration. Here, if each of the light emitting element and the protective element is die-bonded to a package or the like and then connected to the external electrode with a conductive wire, the productivity decreases because the number of bonding of the conductive wire increases. In addition, since there is an increased risk of contact between the conductive wires, disconnection, and the like, the reliability of the light emitting device may be reduced. On the other hand, in the light emitting device in this embodiment, it is only necessary to connect the conductive wire to both the positive and negative electrodes provided on the submount, and it is not necessary to bond the conductive wire to the light emitting element. It does not occur and a highly reliable light-emitting device can be obtained.

  The p-side electrode and the n-side electrode of the light emitting element are mechanically fixed so as to face both the positive and negative electrodes formed on the same surface side of the submount. First, bumps made of Au are formed on both the positive and negative electrodes of the submount. Next, the pad electrode of the light emitting element and the electrode of the submount are opposed to each other through the bump, and the bump is welded by applying a load, heat, and ultrasonic wave, and the electrode of the light emitting element and the electrode of the submount are bonded. To do. In addition to Au, eutectic solder (Au—Sn), Pb—Sn, lead-free solder, and the like can be used as the bump material. Further, the shape and size of the pad electrode of the light emitting element are appropriately selected depending on the size and number of bumps to be installed. Therefore, it is not limited to the shape having the auxiliary electrode as in the first embodiment.

  Further, the submount is fixed to the lead electrode 105 with Ag paste as an adhesive, and the lead electrode 105 and the submount electrode are connected by the conductive wire 108 to obtain a light emitting device.

In each of the above-described embodiments, a light emitting device is formed in the same manner except that a sealing member containing a fluorescent material is used. The fluorescent material is prepared by co-precipitation with oxalic acid of a solution obtained by dissolving a rare earth element of Y, Gd, and Ce in an acid at a stoichiometric ratio with oxalic acid, and calcining the mixture, and then mixing aluminum oxide. To obtain mixed raw materials. Further, barium fluoride is mixed as a flux, then packed in a crucible, and fired in air at a temperature of 1400 ° C. for 3 hours to obtain a fired product. The fired product is ball _milled in water, washed, separated, dried, and finally passed through a sieve to have a center particle size of 8 μm (Y _0.995 Gd _0.005 ) _2.750 Al ₅ O ₁₂ : Ce _0.250 phosphor Form. By including the phosphor, a light-emitting device that can obtain mixed color light from light from the light-emitting element and light obtained by wavelength-converting part of the light from the light-emitting element can be obtained.

  A planar light-emitting device is formed by combining the light-emitting device obtained by the above embodiment and a light guide plate. In this embodiment, the side surface of the package and the end surface of the light guide plate are bonded and fixed with an adhesive. The light guide plate has a concavo-convex shape that can be fitted to the step 110 and the concave portion 112 provided on the side surface of the light emitting device, and easy positioning of the light emitting device and the light guide plate is easy. Both are firmly fixed. The planar light source according to the present embodiment can be easily positioned with the light emitting device according to the other embodiments, and can be a planar light source that is thinner than the conventional one. In addition, by providing a notch portion that scatters light on the light incident surface of the light guide plate, a planar light source that does not cause uneven light emission depending on the light emission position can be obtained.

FIG. 1 is a schematic front view of a light emitting device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. FIG. 3 is a schematic side view of a light emitting device according to an embodiment of the present invention. FIG. 4 is a schematic top view of a light emitting device according to an embodiment of the present invention. FIG. 5 is a schematic top view of a light emitting device according to an embodiment of the present invention. FIG. 6 is a schematic side view of a light emitting device according to an embodiment of the present invention. FIG. 7 is a schematic front view of a light emitting device according to an embodiment of the present invention. FIG. 8 is a schematic front view of a light emitting device according to an embodiment of the present invention. FIG. 9 is a schematic front view of a light emitting device according to an embodiment of the present invention. FIG. 10 is a schematic front view of a light emitting device according to an embodiment of the present invention.

Explanation of symbols

100, 200: Light-emitting devices 101a, 101b, 101c, 102, 104 ... Inner wall surfaces 103, 105 ... Lead electrodes 106 ... Packages 107 ... Light-emitting elements 108 ... Conductivity Wire 109 ... Sealing member 110 ... Step 111 ... Projection 112 ... Recess 113 ... Submount 114 ... Insulating film 115a ... Positive electrode 115b ... Negative electrode 116a, 116b: Bonding region 117a ... Back electrodes 118a, 118b ... Bump 119a ... P-type semiconductor region 119b ... N-type semiconductor region 120 ... Composite element 121 ... Translucent substrate

Claims (3)

A light emitting element, a package in which a lead electrode is exposed on the bottom surface of the opening where the light emitting element is disposed, a conductive wire connecting the electrode of the light emitting element disposed on the bottom surface of the opening and the lead electrode, A light emitting device comprising:
An inner wall surface of the opening, a first inner wall surface that extends in the longitudinal direction of the main surface of the package, and the short and extend in a direction with a pair of opposing second inner wall surface of the main surface of the package , a third inner wall surface facing the second inner connected to the wall surface said first inner wall surface, and a fourth inner wall surface opposed to said first inner wall surface, the fourth interior wall surface and the And a fifth inner wall surface connecting the third inner wall surface ,
The opening has a protruding portion provided such that a part of the opening protrudes toward the outer wall surface of the package by the fourth inner wall surface and a pair of opposing fifth inner wall surfaces, At least a part of the light emitting element is disposed on the bottom surface of the projecting portion, and the conductive wire is wire-bonded to a lead electrode exposed between a pair of opposing second inner wall surfaces. A light emitting device.   The light emitting device according to claim 1, wherein the package has a step or a recess on a side surface thereof. The light-emitting device according to claim 1 or 2, and a light guide plate that guides light from the light-emitting device,
The planar light source, wherein the light guide plate has an uneven shape that fits with an outer wall surface shape of the light emitting device.

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