JP2018056263A - Light-emitting device and method of manufacturing light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device excellent in light extraction efficiency of ultraviolet light.SOLUTION: The light-emitting device includes: a substrate provided with a first region and a second region arranged around the first region on the same surface side; an ultraviolet light-emitting element provided with a first surface bonded to the first region of the substrate via a first bonding member, and a second surface opposite to the first surface; and an inorganic translucent member provided with an element bonding region in direct contact with the second surface of the ultraviolet light-emitting element, and a substrate bonding region bonded to the second region of the substrate via a second bonding member.SELECTED DRAWING: Figure 1B

Description

  The present invention relates to a light emitting device and a method for manufacturing the light emitting device.

  As a light-emitting device such as a light-emitting diode (LED) that emits ultraviolet light, a light-emitting device having a structure sealed with glass is known (for example, Patent Document 1). The glass is bonded to the package with an adhesive or the like.

JP2015-109331A

  When the ultraviolet light is absorbed by the adhesive or the like, the light extraction efficiency decreases.

The present disclosure includes the following configurations.
A first region and a second region disposed around the first region on the same surface side; a first surface bonded to the first region of the substrate via the first bonding member; An ultraviolet light emitting element having a second surface opposite to the first surface, an element bonding region in direct contact with the second surface of the ultraviolet light emitting device, and a second region of the substrate bonded via a second bonding member A light-emitting device comprising: an inorganic translucent member comprising: a substrate bonding region that is provided.

  As described above, a light emitting device having excellent light extraction efficiency of ultraviolet light can be obtained.

FIG. 1A is a schematic top view illustrating the light emitting device according to the embodiment. 1B is a schematic cross-sectional perspective view including a cross section taken along line 1B-1B in FIG. 1A. 1C is a schematic end view taken along line 1B-1B in FIG. 1A. FIG. 2A is a schematic end view of the substrate of the light emitting device according to the embodiment. FIG. 2B is a schematic top view of the substrate of the light emitting device according to the embodiment. FIG. 2C is a schematic top view of the substrate of the light emitting device according to the embodiment. FIG. 3A is a schematic perspective view of an inorganic translucent member of the light emitting device according to the embodiment. 3B is a schematic end view taken along line 3B-3B of FIG. 3A. FIG. 4A is a schematic end view illustrating the method for manufacturing the light emitting device according to the embodiment. FIG. 4B is a schematic end view illustrating the method for manufacturing the light emitting device according to the embodiment. FIG. 4C is a schematic end view illustrating the method for manufacturing the light emitting device according to the embodiment. FIG. 4D is a schematic end view illustrating the method for manufacturing the light emitting device according to the embodiment. FIG. 4E is a schematic end view illustrating the method for manufacturing the light emitting device according to the embodiment. FIG. 4F is a schematic end face illustrating the method for manufacturing the light emitting device according to the embodiment. FIG. 5A is a schematic end view of the light emitting device according to the embodiment. FIG. 5B is a schematic end view of the substrate of the light emitting device according to the embodiment.

  A mode for carrying out the present invention will be described below with reference to the drawings. However, the embodiments described below exemplify a light emitting device and a method for manufacturing the light emitting device for embodying the technical idea of the present invention, and the present invention describes the method for manufacturing the light emitting device and the light emitting device as follows. It is not limited.

  Further, the present specification by no means specifies the member shown in the claims as the member of the embodiment. In particular, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in the embodiments are not intended to limit the scope of the present disclosure to that unless otherwise specified. It should be noted that the size and positional relationship of the members shown in each drawing may be exaggerated for clarity of explanation. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate. In addition, terms indicating specific directions and positions (for example, “up”, “down”, “right”, “left” and other terms including those terms) are used as necessary. The use of these terms is to facilitate understanding of the invention with reference to the drawings, and the technical scope of the present invention is not limited by the meaning of these terms.

  The light emitting device according to the embodiment includes a substrate, an ultraviolet light emitting element, and an inorganic translucent member. The substrate includes a first region and a second region on the same surface side. The second region is a region disposed around the first region in a top view. The ultraviolet light emitting element includes a first surface and a second surface opposite to the first surface. The first surface is bonded to the first region of the substrate via the first bonding member. The inorganic translucent member includes an element bonding region and a substrate bonding region. The element junction region is in direct contact with the second surface of the ultraviolet light emitting element. The substrate bonding region is bonded to the second region of the substrate via the second bonding member.

Since the ultraviolet light emitting element and the inorganic translucent member are in direct contact with each other, the ultraviolet light from the light emitting element is hardly reflected on the surface of the inorganic translucent member. Therefore, ultraviolet light can be efficiently guided into the inorganic translucent member. Thereby, it can be set as the light-emitting device excellent in the light extraction efficiency of ultraviolet light.
Hereinafter, each member will be described in detail.

(substrate)
The substrate is a member for mounting an ultraviolet light emitting element, and includes an insulating base serving as a base material and a conductive member serving as a wiring. A board | substrate can be made into the shape provided with the plate shape or the recessed part which can accommodate a light emitting element. The substrate can be a polygon, such as a quadrangle or a hexagon, a circle, an ellipse, a combination of these, or a shape that is partially missing, as viewed from above.

  The substrate includes a first region and a second region on the same surface side. The second region is arranged around the first region in a top view. The first region and the second region can be located at the same height or at different heights.

  The first region of the substrate is a region bonded to the first surface of the ultraviolet light emitting element via the first bonding member. That is, the first region of the substrate refers to an element mounting region (element bonding region). One or a plurality of ultraviolet light emitting elements can be mounted on one substrate. In the case of using a plurality of ultraviolet light emitting elements, the plurality of element mounting areas are collectively regarded as one first area, and the second area is arranged around the first area. Thus, when a plurality of element placement areas are provided in the first area, the plurality of element placement areas can have the same height or different heights. Preferably, the plurality of element mounting areas have the same height.

  The first region of the substrate has at least two conductive members. The two conductive members function as a pair of positive and negative wiring electrodes. The pair of conductive members of the substrate is bonded to the pair of electrodes of the ultraviolet light emitting element via the first bonding member.

  The first region is a region including a region connected to the ultraviolet light emitting element through the first bonding member as described above, and indicates a region immediately below the ultraviolet light emitting element. That is, the region immediately below the ultraviolet light emitting element is defined as the first region including the region that is not actually in contact with the first bonding member, such as the base exposed between the pair of conductive members.

  The size and shape of the first region of the substrate are determined according to the size and shape of the ultraviolet light emitting element to be placed. For example, when the ultraviolet light emitting element is a square having a top view of 1 mm × 1 mm, the first region is a 1 mm × 1 mm region immediately below the ultraviolet light emitting element.

  The second region of the substrate is a region bonded to the inorganic translucent member via the second bonding member. The second area is arranged around the first area. When the ultraviolet light emitting element is hermetically sealed, the second bonding member is formed over the entire circumference of the second region, and when the ultraviolet light emitting element is non-hermetic sealed, the second bonding member is the second region. Formed in part. A region provided so as to surround the first region, including a region where the second bonding member is not bonded, is defined as a second region.

  The second region includes only the base of the substrate, only the first metal layer formed on the base of the substrate, or either the base or the first metal layer. By providing the first metal layer in the second region, the bondability between the second bonding member and the substrate can be improved. In other words, the first metal layer can function as a joining auxiliary member.

  The first metal layer is electrically separated from the pair of conductive members functioning as wiring electrodes, and can function only as a joining auxiliary member. Or the part electrically connected with the electrically-conductive member which functions as a wiring electrode, ie, a part of electrically-conductive member, may be sufficient.

  The first metal layer can be a single metal member arranged in an annular shape over the entire second region. Alternatively, the first metal layer can be a metal member partially formed in the second region. That is, the first metal layer may be plural. In the case of a plurality of first metal layers, it is preferable to arrange them in a balanced manner, such as a symmetrical arrangement, a point-symmetric arrangement, or a constant interval.

  The substrate may include a third region between the first region and the second region. The third region is the upper surface of the substrate excluding the region directly below the ultraviolet light emitting element and the region bonded to the inorganic translucent member. This third region is a region facing the translucent substrate, and is constituted by a base or a conductive member.

  The space formed by the third region of the substrate and the inorganic translucent member can be composed of a gas such as air, for example. This gas is in contact with the side surface of the ultraviolet light emitting element. As a result, the refractive index difference between the ultraviolet light emitting element and the gas increases, so that light emitted from the side surface can be suppressed, light emission from the second surface in contact with the inorganic translucent member increases, and the light emitting device with high output Can be obtained. A part of the light from the ultraviolet light emitting element is also emitted from the side surface. The light emitted from the side surface propagates in the gas and then enters the inorganic translucent member again. When providing a reflecting member on the inclined surface of the inorganic translucent member, it is preferable to provide a reflecting member also on the side surface of the ultraviolet light emitting element.

  Various functional members can be arranged in the third region of the substrate according to the purpose and application. Functionalities such as protective elements such as Zener diodes, wavelength conversion members that absorb ultraviolet light and convert visible light, light reflecting members that reflect ultraviolet light, and adsorbing members such as zeolite that adsorb organic matter and moisture Members may be placed.

  The base is preferably made of a material that can reflect light from the light emitting element. In particular, it is preferable to reflect light from the light emitting element by 60% or more and 70% or more. In addition, it is preferable that the light-emitting element is formed using a material that hardly absorbs light. For example, insulating materials such as glass, ceramics, resin, wood, pulp, etc., single materials of conductive materials such as semiconductors, metals (eg, copper, silver, gold, aluminum, nickel, chromium, tin, palladium, etc.) and these It can be formed by a composite material. Of these, metals, ceramics, resins, and the like are preferable, and ceramics that are inorganic materials are more preferable. As the ceramic, aluminum nitride having high heat dissipation is particularly preferable.

  The conductive member is not particularly limited as long as it can be electrically connected to the light emitting element, and can be formed using a material known in the art. For example, metals such as copper, aluminum, gold, and silver can be used. The thickness can be several μm to several hundred μm. The conductive member can be formed by plating, sputtering, or other known methods. Further, the conductive member is disposed on the surface on which the ultraviolet light emitting element is placed, and is also disposed on the upper surface, side surface, or lower surface of the substrate as an external connection terminal. When the conductive material is disposed on the lower surface of the substrate, it is electrically connected to the first metal layer on the upper surface of the substrate by a metal member provided inside or on the side surface.

  When the first metal layer is used as a part of the conductive member, the above-described materials can be used. In addition, for the first metal layer that is electrically separated from the conductive member, a material that can improve the bondability with the second bonding member can be selected. For the first metal layer, a material having a good bondability with the base of the substrate can be selected. Examples of the first metal layer include gold (Au), silver (Ag), copper (Cu), nickel (Ni), titanium (Ti), chromium (Gr), tin (Sn), aluminum (Al), and palladium. (Pd) Single material such as platinum (Pt), rhodium (Rh), t tungsten (W), molybdenum (Mo), iron (Fe), and a composite material thereof may be mentioned. The thickness of the first metal member can be several μm to several hundred μm. The first metal layer can be formed by plating, sputtering, or other known methods. Moreover, when the 1st metal member is a part of electrically-conductive member, or when it does not contribute to electricity supply, in any case, when using the same material as an electrically-conductive member, it can form simultaneously.

(Ultraviolet light emitting device)
The ultraviolet light emitting element is a semiconductor light emitting element capable of emitting ultraviolet light. The ultraviolet light emitting element includes a first surface and a second surface opposite to the first surface. The first surface is a surface that is bonded to the first region of the substrate via the first bonding member. The second surface is a surface that is in direct contact with the element bonding region of the inorganic translucent member. Here, the ultraviolet light refers to light having an emission peak wavelength of 200 to 410 nm, for example. The number of ultraviolet light emitting elements used in one light emitting device is one or more than two. When a plurality of ultraviolet light emitting elements are used, for example, ultraviolet light emitting elements having the same emission peak wavelength may be used, or ultraviolet light emitting elements having different emission peak wavelengths. It may be. The size and shape of the ultraviolet light emitting element can be appropriately selected according to the purpose and application. For example, the top view shape of the ultraviolet light emitting element can be a polygon such as a quadrangle (square or rectangle), a triangle, a hexagon, or a combination of these.

  The ultraviolet light emitting element includes at least a stacked structure including a semiconductor layer including a light emitting layer, and a pair of electrodes. The laminated structure may include a light-transmitting substrate in addition to the semiconductor layer. Further, the pair of electrodes are formed in the semiconductor layer of the stacked structure. For example, a p-side electrode is formed on the p-type semiconductor layer, and a b-side electrode is formed on the n-type semiconductor layer. The 1st surface of an ultraviolet light emitting element is a surface in which the electrode was formed, and the 2nd surface is a surface comprised by a translucent substrate or a semiconductor layer.

As the semiconductor layer, for example, can utilize a nitride-based semiconductor _{(In X Al Y Ga 1-} X-Y N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) semiconductor such.

  As the light-transmitting substrate, a growth substrate or a bonded substrate can be used. Examples of the light transmissive substrate include sapphire and nitride semiconductor.

The electrodes are A u, P t, P d, R h, N i, W, M o, C r,
A metal such as Ti or an alloy containing these can be used, and a single layer or a stacked structure can be used. The shape, size, arrangement, and the like of the electrode can be appropriately selected according to the purpose and application.

(Inorganic translucent member)
An inorganic translucent member is a member which coat | covers an ultraviolet light emitting element, and is provided with the property which permeate | transmits the light from an ultraviolet light emitting element. Here, translucency refers to transmitting 70% or more of light from the ultraviolet light emitting element.

  The inorganic translucent member includes an element bonding region that is in direct contact with the second surface of the ultraviolet light emitting element, and a substrate bonding region that is bonded to the second region of the substrate via the second bonding member. The element bonding region and the substrate bonding region can be located on the same surface or on different surfaces depending on the shape of the substrate. In addition, the substrate bonding region of the inorganic translucent member is disposed around the element bonding region in the top view in the same manner as the second region of the substrate is disposed around the first region in the top view. .

  The element bonding region of the inorganic translucent member is a surface that is in contact with the second surface of the ultraviolet light emitting element and functions as a light incident surface on which light from the ultraviolet light emitting element is incident. Similar to the first region of the substrate, the element bonding region of the inorganic translucent member refers to a region immediately below the ultraviolet light emitting device. As for the size of the element junction region, the same size as the second surface of the ultraviolet light emitting element is the maximum, and about 1/2 the size of the second surface of the ultraviolet light emitting element is the minimum. The size of the element junction region is preferably the same as that of the second surface of the ultraviolet light emitting element. Thereby, the light from an ultraviolet light emitting element can be efficiently incident on an inorganic translucent member.

  The substrate bonding region of the inorganic translucent member is a region bonded to the second region of the substrate via the second bonding member. The substrate bonding region is disposed around the element bonding region. When the ultraviolet light emitting element is hermetically sealed, the second bonding member is formed over the entire circumference of the substrate bonding region. When the ultraviolet light emitting element is hermetically sealed, the second bonding member is the substrate bonding region. Formed in part. The region provided so as to surround the element bonding region including the region that is not bonded to the second bonding member in this way is defined as a substrate bonding region.

  The second metal layer may be a single metal member arranged in an annular shape over the entire substrate bonding region. Alternatively, the second metal layer can be a metal member partially formed in the substrate bonding region. That is, the second metal layer may be plural. In the case of a plurality of second metal layers, it is preferable to arrange them in a balanced manner, such as a symmetrical arrangement, a point-symmetric arrangement, or a constant interval.

  The substrate bonding region is composed of an inorganic translucent member or a second metal layer formed on the inorganic translucent member. By providing the second metal layer in the substrate bonding region, the bonding property between the second bonding member and the inorganic translucent member can be improved. Similar to the first metal layer provided on the substrate, the second metal layer can also function as a joining auxiliary member. For the second metal layer, a material capable of improving the bondability with the second bonding member can be selected. In addition, the second metal layer can be selected from a material having good bonding properties with the translucent member. As the second metal layer, for example, the same material as the first metal can be used.

  The inorganic translucent member can be provided with a region different from these between the element bonding region and the substrate bonding region. This region is a region facing the third region of the substrate, and can function as, for example, a light reflecting surface. Thus, when making a part of inorganic translucent member function as a light reflection surface, a light reflection member can be provided, for example. As the light reflecting member, metals such as Ag and Al, and white reflecting members such as titanium oxide, aluminum oxide, and zirconium oxide can be used. Further, the light reflecting surface can be a surface inclined with respect to the light incident surface which is the element mounting region.

  In the inorganic translucent member, the surface opposite to the element bonding region is a surface that functions as a light emitting surface from which light is emitted to the outside. The light emitting surface of the inorganic translucent member can be a flat surface, a curved surface, or a surface combining these. For example, when the light exit surface is a hemispherical surface, it can function as a convex lens.

  For example, glass, sapphire, or the like can be used as the inorganic translucent member. Further, the substrate bonding region bonded to the second bonding member or the region functioning as a light reflecting surface may be provided with a non-light transmissive member such as a metal layer, a reflective member, or the like. Moreover, you may contain a diffuser, a wavelength conversion member, etc. in the inside of an inorganic translucent member.

(First joining member)
The first joining member is a member that joins the first region of the substrate and the first surface of the ultraviolet light emitting element. Specifically, in the first region, the conductive member that functions as the wiring electrode and the electrode formed on the first surface of the ultraviolet light emitting element are electrically joined.

  The first joining member is, for example, tin-bismuth, tin-copper, tin-silver, gold-tin, or the like, Au and Sn, Au and Si, Au and Ge, Au and Cu, Ag and Cu. And eutectic alloys such as alloys mainly containing silver, conductive pastes such as silver, gold, palladium, etc., conductive bonding members such as bumps, anisotropic conductive materials, and low melting point metal brazing materials. It is done. In particular, it is preferable to use a eutectic alloy such as a solder or an alloy that hardly deteriorates by ultraviolet light, or a bump.

  The thickness of the first joining member is preferably thinner than the thickness of the second joining member. For example, it can be set to about 3 μm to 50 μm.

(Second joining member)
The second bonding member is a member that bonds the second region of the substrate and the substrate bonding region of the inorganic translucent member. As the second bonding member, a conductive bonding member similar to the material used as the first bonding member can be used. Furthermore, an insulating bonding member can be used. For example, resin etc. are mentioned.

  When the light emitting device has an airtight sealing structure, at least one second bonding member that is continuous over the entire second region of the substrate is disposed. When the light emitting device has a non-hermetic structure, a plurality of spaced apart second joining members are arranged in the second region of the substrate. When a plurality of second joining members are used, it is preferable to arrange them in a balanced manner, such as a left-right symmetrical arrangement, a point-symmetrical arrangement, or a constant interval in the top view of the substrate. Thereby, it can suppress that load concentrates locally at the time of joining of a substrate and an inorganic translucent member.

  When the second bonding member is partially provided, a space between the second bonding member and the second bonding member adjacent to the second bonding member is a portion serving as a vent in the case of a non-airtight structure. Breathability can be improved by enlarging the portion that becomes the vent. In addition, reducing the portion serving as the vent indicates that the region for forming the second bonding member is increased. In this case, the bonding property between the substrate and the inorganic translucent member is improved. be able to.

  The thickness of the second bonding member is preferably thicker than the thickness of the first bonding member. Compressive stress is generated at the time of bonding in the ultraviolet light emitting element or the joint between the ultraviolet light emitting element and the inorganic translucent member. Therefore, by increasing the thickness of the second bonding member, bonding between the ultraviolet light emitting element and the inorganic translucent member and stress damage to the ultraviolet light emitting element can be reduced. The thickness of the second bonding member can be, for example, about 10 μm to 100 μm.

<Embodiment 1>
A light emitting device 100 according to Embodiment 1 is shown in FIGS. 1A to 1C. 1A is a schematic top view of a light emitting device 100 according to Embodiment 1, FIG. 1B is a schematic cross-sectional perspective view including a cross section taken along line 1B-1B in FIG. 1A, and FIG. 1C is a schematic end face taken along line 1B-1B in FIG. FIG. The light emitting device 100 includes a substrate 110, an ultraviolet light emitting element 120 placed on the substrate, and an inorganic translucent member 130.

(substrate)
A schematic end view of the substrate 110 is shown in FIG. 2A. The substrate 110 includes a first region 1101 and a second region 1102 disposed around the first region 1101. In Embodiment 1, the board | substrate 110 is provided with the recessed part S which has a side wall and a bottom face. The bottom surface of the recess S has an area where the ultraviolet light emitting element 120 can be placed.

  FIG. 1A shows an example in which the outer shape of the substrate 110 is substantially square, and the bottom surface of the recess S is substantially square. Further, the outer shape of the substrate 110 and the shape of the bottom surface of the recess S may be the same or different.

  FIG. 1A shows an example in which the side wall height of the recess S is higher than the height of the ultraviolet light emitting element 120. However, the height of the side wall is not limited to this, and may be the same as or lower than the height of the ultraviolet light emitting element 120. The inner side surface of the side wall may be a surface that is perpendicular or inclined with respect to the bottom surface, a surface that further includes a step, and the like.

  In the first embodiment, the first region 1101 is at least a part of the bottom surface of the recess, and the second region 1102 is at least a part of the top surface of the side wall. In other words, the first region 1101 and the second region 1102 are not arranged on the same plane but on different heights. Both are disposed on the same surface side (upper surface side) of the substrate 110 and are parallel to each other. However, the first region 1101 and the second region 1102 may not be parallel to each other but may be surfaces inclined by about ± 3 degrees. Including such a case, it is assumed that they are arranged on the same surface side.

  The second area 1102 is arranged around the first area 1101. FIG. 1 shows an example in which the first area 1101 is arranged at the center of the area surrounded by the second area 1102. Not limited to this, the first region 1101 can be arranged at an arbitrary position in the region surrounded by the second region 1102.

  The substrate 110 includes an insulating base 111 and a pair of conductive members 112. For example, the board | substrate 110 provided with the base | substrate 111 which consists of alumina which is ceramic, and the electrically-conductive member 112 whose outermost surface is gold | metal | money is mentioned. The conductive member 112 functions as a pair of positive and negative wiring electrodes for supplying power to the ultraviolet light emitting element. On the bottom surface of the concave portion of the substrate 110, the two conductive members 112 are arranged at positions separated from each other.

  In the first embodiment, the first metal layer 113 is disposed in the second region 1102. The first metal layer 113 is a metal that is not energized, and is a joining auxiliary member that improves the joining strength between the substrate and the second joining member.

  As shown in FIG. 1A and the like, the first metal layer 113 is formed in an annular shape over the entire circumference on the upper surface of the side wall of the substrate 110. The width of the first metal layer 113 may be the same as or narrower than the width of the upper surface of the side wall. In FIG. 1A and the like, the first metal layer 113 having a width narrower than the width of the upper surface of the sidewall is illustrated. In FIG. 1A, the hatched area is the upper surface of the side wall, and the area that is overlapped with the light ink is the first metal layer 113.

  Further, the width of the upper surface of the side wall is such that both ends of the first metal layer 113 are positioned at positions spaced from both ends in the width direction. Thus, by setting it as the 1st metal layer 113 whose width | variety is narrower than the upper surface of a side wall, it can prevent that a 2nd joining member protrudes from the upper surface of a side wall, for example.

  2B and 2C are schematic top views showing a modification of the first metal layer 113 of the substrate 110 shown in FIG. 1A. The light-inked portion is the first metal layer. A substrate 110A shown in FIG. 2B includes four L-shaped first metal layers 113A extending in two directions from four corners on the upper surface of the side wall of the recess. That is, in the annular second region 1102A, four first metal layers 113A that are separated from each other are arranged. Thus, the 2nd joining member can also be spaced apart by setting it as the 1st metal layer 113A which spaces apart. Accordingly, a light-emitting device having a non-hermetic structure can be obtained. Further, the second bonding member can be formed in a wider range than the substrate 110B shown in FIG. 2C. That is, the ratio occupied by the first metal layer 113A in the second region 1102 is relatively large. Therefore, the bonding strength between the substrate 110 and the translucent member can be improved.

  Further, the substrate 110B shown in FIG. 2C includes four substantially rectangular first metal layers 113B located on two corners on the upper surface of the side wall of the recess. As described above, in the annular second region 1102B, by reducing the ratio indicated by the first metal layer 113B, a load applied when the substrate and the inorganic translucent member are bonded can be reduced. Moreover, the air permeability of the space between a board | substrate and an inorganic translucent member can be improved. Therefore, for example, when a member including a volatile component is provided in the space, the volatile component can be easily discharged to the outside. In addition to the first metal layer shown in FIGS. 2B and 2C, various shapes, sizes, and arrangements can be used.

(Ultraviolet light emitting device)
The ultraviolet light emitting element 120 includes a first surface 121 and a second surface 122 opposite to the first surface 121. The first surface 121 is bonded to the first region 1101 of the substrate 110 via the first bonding member 141. The second surface 122 is in direct contact with the element bonding region 130 </ b> A of the inorganic translucent member 130.

The ultraviolet light emitting element 120 includes a semiconductor layer made of a nitride semiconductor (In _X Al _Y Ga _1- XYN, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1), sapphire that is a light-transmitting substrate, It has a laminated structure provided with. Furthermore, the semiconductor layer can be provided with a pair of positive and negative electrodes. The first surface 121 of the ultraviolet light emitting element 120 is a surface on which a pair of positive and negative electrodes is formed. The second surface 122 of the ultraviolet light emitting element 120 is made of sapphire. Note that the semiconductor layer forms the second surface 122 when the stacked structure does not include a light-transmitting substrate.

  The ultraviolet light emitting element 120 is, for example, a square with a top view of 1 mm × 1 mm, and an emission peak wavelength is 360 nm to 370 nm. The electrode may include a pad electrode made of Au, an auxiliary electrode made of Au, Ni, Cu, and Pt, and ITO, ZnO, or the like as a light-transmitting electrode.

(Inorganic translucent member)
A schematic perspective view of the inorganic translucent member 130 is shown in FIG. 3A. FIG. 3B is a schematic cross-sectional view taken along line 3B-3B in FIG. 3A and shows a state in which the second metal layer is provided. The inorganic translucent member 130 has an element bonding region 130A and a substrate bonding region 130B.

  The inorganic translucent member 130 has a substantially square shape when viewed from above, and has an outer size substantially the same as the outer size of the substrate. Further, as shown in FIG. 3A and the like, it has a shape having a convex portion on the lower side, and the top surface of this convex portion is an element bonding region 130A. In addition to the substantially square frustum shape as shown in FIG. In that case, the element mounting area is circular.

  The element bonding region 130A is a surface in which the second surface of the ultraviolet light emitting element 120 is in direct contact, and is a substantially rectangular region surrounded by the substrate bonding region 130B in a top view. The element bonding region 130 </ b> A is substantially square when viewed from above, and is disposed at the center of the inorganic translucent member 130. Each side of the element bonding region 130A and the inner side of the substrate bonding region 130B are arranged in parallel.

  The substrate bonding region 130 </ b> B is a region bonded to the second region 1102 of the substrate 110 via the second bonding member 142. In the first embodiment, the substrate 110 includes the recess S, and the upper surface of the side wall is the second region 1102. Therefore, the substrate bonding region 130 </ b> B of the inorganic translucent member 130 can be an annular region having the same width as the second region 1102.

  The substrate bonding region 130B is composed of an inorganic translucent member or a second metal layer 134 formed on the inorganic translucent member. Similar to the first metal layer 113 of the substrate 110, the second metal layer 134 can have the same width as the substrate bonding region 130B or a smaller width. Furthermore, as shown in FIG. 2B and FIG. 2C, the second bonding member 142 may be formed in two or more separated regions as in the case of the plurality of first metal layers 113A and 113B separated from each other. In particular, by making the first metal layer and the second metal layer have the same shape so as to face each other, it is possible to easily control the spread of the second bonding member.

  An inclined surface 130D is provided between the element bonding region 130A and the substrate bonding region 130B. The angle Θ of the inclined surface 130D can be a surface inclined by, for example, 1 degree to 70 degrees with respect to the element bonding region 130A. By reducing the angle Θ, the inorganic translucent member and the substrate can be thinned, and the light emitting device can be thinned. Moreover, the energy of light per unit area can be increased by increasing the angle Θ. The inclined surface 130D can function as a light reflecting surface. For example, a light reflecting member may be provided.

  In the inorganic translucent member 130, the surface opposite to the element bonding region 130A is a surface that functions as a light emitting surface 130C from which light is emitted to the outside. As shown in FIGS. 1A, 3B, etc., in the first embodiment, an example in which the light exit surface 130C is a flat surface is shown.

  The above-described light emitting device 100 can be obtained by a manufacturing method including steps as shown in FIGS. 4A to 4F. As an outline of each step, 1) a step of preparing an ultraviolet light emitting element, 2) a step of preparing an inorganic translucent member, 3) a step of preparing a substrate, 4) an inorganic translucent member and an ultraviolet light emitting device. The process of joining, 5) The process of joining an inorganic translucent member and an ultraviolet light emitting element, and a board | substrate is mentioned. In addition, it is not necessary to perform the process of preparing each member shown to 1) -3) in this order, and you may carry out in any order.

1) Step of Preparing an Ultraviolet Light Emitting Element As shown in FIG. 4A, an ultraviolet light emitting element 120 having a first surface 121 and a second surface 122 is prepared. The first surface 121 is provided with electrodes. In this step, such an ultraviolet light emitting device 120 can be purchased and prepared, or an ultraviolet light emitting device can be prepared and prepared through a step of forming a semiconductor laminated structure or electrode. Alternatively, an ultraviolet light emitting device 120 may be prepared by purchasing an assembly of ultraviolet light emitting devices in a wafer state and dividing them into individual pieces.

2) Step of Preparing Inorganic Translucent Member As shown in FIG. 4B, an inorganic translucent member 130 including an element bonding region 130A and a substrate bonding region 130B is prepared. In the inorganic translucent member 130, the element bonding region 130A protrudes above the substrate bonding region 130B. A second metal layer 134 is formed in the element bonding region. In this step, such an inorganic translucent member 130 is purchased and prepared, or prepared by processing and preparing the inorganic translucent member, forming the second metal layer 134, and the like. Can do.

3) Step of Preparing Substrate As shown in FIG. 4C, a substrate 110 having a first region 1101 on the bottom surface of the recess S and a second region 1102 on the top surface of the sidewall of the recess S is prepared. A first metal layer 113 is formed in the second region 1102. This step can be prepared by purchasing and preparing such a substrate 110, or by processing the base 111, forming a conductive member 112 or a first metal layer 113, and the like.

4) Step of Bonding Inorganic Translucent Member and Ultraviolet Light Emitting Element As shown in FIG. 4D, second surface 122 of ultraviolet light emitting element 120 and element bonding region 130A of inorganic translucent member 130 are in direct contact with each other. To join. This bonding is a direct bonding, and for example, a surface activated bond, a hydroxyl group bond, or an atomic diffusion bond can be used. Surface activated bonding is a method of bonding bonding surfaces to each other in a surface state that facilitates chemical bonding by treating the bonding surfaces in a vacuum. Hydroxyl bonding is a method in which, for example, a hydroxyl group is formed on the bonding surface by an atomic layer deposition method or the like, and the hydroxyl groups on each bonding surface are bonded to each other. By such direct bonding, the ultraviolet light emitting element 120 and the inorganic translucent member 130 can be directly contacted in an environment close to normal temperature. In addition, a part of the ultraviolet light emitting element 120 and a part of the inorganic translucent member 130 are integrated by direct bonding, and this integrated part has a different property from the member before the integration. It has become a member. This part is also referred to as a directly joined part.

5) Step of Bonding Inorganic Translucent Member and Ultraviolet Light Emitting Element and Substrate As shown in FIG. 4E, a first bonding member 141 is formed on the first surface 121 of the ultraviolet light emitting element 120. Similarly, the second bonding member 142 is formed on the second metal layer 134 of the inorganic translucent member 130.

  Next, the joined body of the inorganic translucent member 130 and the ultraviolet light emitting element 120 obtained in FIG. 4E is turned upside down. Then, as shown in FIG. 4F, the first region 1101 of the concave portion S of the substrate 110 and the first surface 121 of the ultraviolet light emitting element 120 face each other, and the second region 1102 of the substrate 110 and the inorganic translucent member. 130 substrate bonding regions 130B are made to face each other. Then, the first bonding member 141 and the second bonding member 142 provided on the inorganic translucent member 130 are brought into contact with the first region 1101 and the second region 1102 provided on the substrate 110.

  Finally, the light emitting device 100 shown in FIGS. 1A to 1C can be obtained by completing the bonding through a heating step.

<Embodiment 2>
A light emitting device 200 according to Embodiment 2 is shown in FIG. FIG. 5 is a schematic end view, and the shape of the top view is substantially square like the light emitting device 100 as shown in FIG. 1A. FIG. 5B is a schematic end view of the inorganic translucent member 230. The light emitting device 200 according to the second embodiment includes a substrate 210, an ultraviolet light emitting element 220 placed on the substrate, and an inorganic translucent member 230.

  In the second embodiment, the substrate 210 has a flat plate shape. Further, in the inorganic translucent member 230, the element bonding region 230 </ b> A bonded to the ultraviolet light emitting element 220 is on the upper side (higher position) than the substrate bonding region 230 </ b> B bonded to the second region 2102 of the substrate. The light-emitting device 200 can be made thinner than the light-emitting device 100 according to the first embodiment in which the substrate 210 has a recess.

  In the inorganic translucent member 230, the distance between the element bonding region 230 </ b> A functioning as a light incident surface and the light emitting surface 230 </ b> C on the opposite side is shorter than that in the first embodiment. Therefore, light is not easily absorbed and light extraction efficiency is excellent.

  The inorganic translucent member 230 has a plane portion 230E including a surface that is on the same plane as the element bonding region 230A between the element bonding region 230A and the substrate bonding region 230B disposed around the element bonding region 230A. Similar to the inclined surface 130D of the first embodiment, the flat portion 230E is a surface facing the substrate 210, and can function as a light reflecting surface.

  A light emitting device according to an embodiment of the present invention includes a printing ink curing light source, a resin curing light source, an exposure device light source, a projector, an illumination light source, various indicator light sources, an in-vehicle light source, a display light source, and a liquid crystal back light. It can be used for various light sources such as light sources for lights, traffic lights, in-vehicle components, and channel letters for signboards.

DESCRIPTION OF SYMBOLS 100, 200 ... Light-emitting device 110, 110A, 110B, 220 ... Substrate 1101, 2201 ... 1st area | region 1102, 2102 ... 2nd area | region 1103 ... 3rd area | region 111, 212 ... Base | substrate 112, 212 ... Conductive member 113, 113A, 113B DESCRIPTION OF SYMBOLS 213 ... 1st metal layer S ... Concave part 120, 220 ... Ultraviolet light emitting element 121 ... 1st surface 122 ... 2nd surface 130, 230 ... Inorganic translucent member 130A, 230A ... Element junction area (light incident surface)
130B, 230B ... substrate bonding region 130C, 230C ... light emitting surface 130D ... inclined surface (light reflecting surface)
230E ... Planar part 134 ... Second metal layer 141, 241 ... First joining member 142, 242 ... Second joining member

Claims (5)

A substrate comprising a first region and a second region disposed around the first region on the same side;
An ultraviolet light emitting device comprising: a first surface bonded to the first region of the substrate via a first bonding member; and a second surface opposite to the first surface;
An inorganic translucent member comprising: an element bonding region in direct contact with the second surface of the ultraviolet light emitting element; and a substrate bonding region bonded to the second region of the substrate via a second bonding member;
A light emitting device comprising:   The light emitting device according to claim 1, wherein a thickness of the first joining member is thinner than a thickness of the second joining member.   The light emitting device according to claim 1, wherein the second joining member is continuously arranged over the entire area of the second region.   The light emitting device according to claim 1, wherein the second joining member is partially arranged in the second region. Preparing an ultraviolet light emitting element comprising a first surface and a second surface opposite to the first surface;
Preparing an inorganic translucent member comprising an element bonding region and a substrate bonding region;
Preparing a substrate comprising a first region and a second region disposed around the first region on the same surface side;
Bonding the element bonding region of the inorganic translucent member and the second surface of the ultraviolet light emitting element;
The first region of the substrate and the first surface of the light emitting element are bonded via a first bonding member, and the second region of the substrate and the substrate bonding region of the inorganic translucent member are bonded to each other. Joining through a member;
A method for manufacturing a light emitting device.

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