JP2012089539A - Light-emitting device, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device having a prolonged life time by arranging a high reflectance member in the vicinity of a pole of a light-emitting element without using silver plating and without compromising electrical connection, and capable of efficiently exciting light from the light-emitting element and having a high light extraction efficiency.SOLUTION: A light-emitting device comprises: a substrate 11 consisting of a substrate insulating part 11a having a recess 11c on its surface and a substrate conductive part 11b a part of which is buried in the substrate insulating part 11a and exposed at least on a rear face of the recessed part 11c; a semiconductor light-emitting element 12; a reflective member 13 arranged in the recessed part 11c; a phosphor layer 14 arranged on the reflective member 13; and a sealing member 15 coating the semiconductor light-emitting element 12. The recess 11c has a protrusion 11d having an upper surface equivalent to or smaller than the semiconductor light-emitting element at the center thereof. The semiconductor light-emitting element 12 is mounted on the protrusion 11d. The reflective member 13 coats the inner surface of the recessed part 11c and a lateral face of the protrusion 11d.

Description

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

In general, a light emitting device includes an electronic component such as a semiconductor light emitting element or a protective element, a base on which the electronic component is mounted, and a translucent member that covers the electronic component to protect the electronic component. In order to increase the light output and the reliability of the light emitting device, not only the characteristics of the light emitting element itself to be used but also the improvement of the design, material and assembly process of the substrate are very effective.
In recent years, LEDs based on ceramics are generally on the market due to high heat resistance, high weather resistance, low cost, freedom of shape, and the like. Since the ceramic itself has a lower reflectance than a metal film such as silver, silver is often plated on the bottom surface of the concave portion of the base on which the light emitting element is mounted to improve light extraction from the base.

However, silver has low weather resistance, and when coated with an organic substance, it causes a decrease in light output of the LED due to aging of silver.
Thus, it has been proposed to coat silver with an inorganic film or a metal film (for example, Patent Document 1), but the former is still not satisfactory enough to maintain the reflectance of silver over a long period of time. . In the latter case, there is no problem in weather resistance, but a decrease in reflectance is unavoidable compared to silver.

On the other hand, the side surface of the concave portion of the substrate is often not plated with silver, and light absorption by the ceramic surface occurs, causing a decrease in light extraction efficiency.
Thus, the side surface of the concave portion of the substrate may be coated with a resin containing a material having high reflectance (for example, Patent Document 2), but it is difficult to cover the resin with the resin up to the very vicinity.

Further, when the light emitting element is covered with a translucent member, the phosphor is mixed in the translucent member, and the phosphor is settled to the lower layer of the translucent member between the potting and curing of the translucent member. There has been proposed a method (for example, Patent Document 3).
However, depending on the concentration of the phosphor, deposition of the phosphor on the lower layer of the translucent member becomes thick, so that the light-emitting layer of the light-emitting element is buried in the phosphor, and light extraction from the light-emitting element is hindered. In particular, in lighting applications, it is required to increase the phosphor concentration in order to provide a low color temperature, and it is necessary to balance the trade-off relationship between a high phosphor concentration and an improvement in luminous efficiency. .

JP 2006-351964 A JP 2004-40099 A JP 2000-315824 A

  The present invention has been made in view of the above problems, and does not rely on silver plating with low weather resistance, and by providing a high light reflectance member in the immediate vicinity of the light emitting element without impairing electrical connection, An object of the present invention is to provide a light-emitting device that enhances the performance, excites light from the light-emitting element efficiently, and has high light extraction efficiency.

The present invention includes the following inventions.
A base body comprising a base body conductive portion that has a concave portion on the surface and a base conductive portion that is partially embedded in the base insulating portion and exposed at least on the back surface of the concave portion;
A semiconductor light emitting element; and a reflective member disposed in the recess;
A phosphor layer disposed on the reflecting member;
A sealing member that covers the semiconductor light emitting element,
The concave portion has a convex portion having an upper surface equal to or smaller than the semiconductor light emitting element at the center thereof, and the semiconductor light emitting element is placed on the convex portion,
The reflection member covers the inner surface of the concave portion and the side surface of the convex portion.

Such an invention preferably includes one or more of the following.
(1) The convex portion has a height equivalent to the depth of the concave portion.
(2) The reflective member is located on the outer edge of the convex portion, or is located on the bottom surface side of the convex portion, or the same as the upper surface thereof.
(3) The reflection member has a convex curved surface on the bottom surface side between the outer edge of the concave portion and the outer edge of the convex portion.
(4) The phosphor layer is formed on the curved surface of the reflecting member and on the upper surface of the semiconductor light emitting element.
(5) The phosphor layer includes a phosphor and a translucent resin, and the phosphor is unevenly distributed on the reflecting member side in the translucent resin.
(6) The sealing member is disposed only above the concave portion of the base body.

The present invention includes the following inventions.
(A) A base insulating portion having a concave portion on the surface and a base conductive portion that is partially embedded in the base insulating portion and exposed at least on the back surface of the concave portion, and an upper surface of the convex portion of the base having a convex portion at the center of the concave portion A semiconductor light emitting element having a plane area equal to or larger than the area of the upper surface of the convex part,
(B) electrically connecting the semiconductor light emitting element to the base conductive portion;
(C) filling a reflective member into a concave portion surrounding the convex portion of the base, and covering the reflective member with the inner surface of the concave portion and the side surface of the convex portion;
(D) A method for manufacturing a light emitting device, wherein a phosphor layer material containing a phosphor is applied by a potting method, and the phosphor is disposed on the reflecting member.

Such an invention preferably includes one or more of the following.
(1) The reflecting member is disposed on the outer edge of the convex portion, or on the bottom surface side of the convex portion.
(2) The reflecting member is formed into a curved surface convex on the bottom surface side between the outer edge of the concave portion and the outer edge of the convex portion on the upper surface of the reflecting member.
(3) The phosphor layer includes a phosphor and a translucent resin, and the phosphor is unevenly distributed on the reflecting member side in the translucent resin.

According to the light emitting device of the present invention, the life resistance can be improved without relying on silver plating with low weather resistance. Further, by further exciting light from the light emitting element, further improvement in light extraction efficiency can be realized.
Furthermore, according to the method for manufacturing a light emitting device of the present invention, a light emitting device with high light extraction efficiency can be manufactured easily and reliably.

BRIEF DESCRIPTION OF THE DRAWINGS (A) Top view which shows Embodiment 1 of the light-emitting device of this invention, (B) A-A 'sectional view, (C) It is a side view. FIG. 6A is a plan view, FIG. 5B is a cross-sectional view taken along line A-A ′, and FIG. FIG. 6A is a plan view, FIG. 5B is a cross-sectional view taken along line A-A ′, and FIG. FIG. 6A is a plan view, FIG. 5B is a cross-sectional view taken along line A-A ′, and FIG. FIG. 7A is a plan view, FIG. 5B is a cross-sectional view taken along line A-A ′, and FIG. FIG. 7A is a plan view, FIG. 7B is a cross-sectional view taken along the line A-A ′, and FIG. (A) Top view, (B) A-A 'line sectional view, (C) Side view showing a light emitting device according to a seventh embodiment of the present invention. FIG. 9A is a plan view, FIG. 9B is a cross-sectional view taken along line A-A ′, and FIG. It is (A) top view, (B) A-A 'sectional view, and (C) side view which show Embodiment 9 of the light-emitting device of this invention. 1A is a plan view, FIG. 1B is a sectional view taken along line A-A ′, FIG. 2C is a rear view, and FIG. FIG. 2A is a plan view and FIG. 2B is a cross-sectional view taken along line A-A ′ showing a substrate that constitutes the light emitting device of the present invention.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the modes described below exemplify a light emitting device for embodying the technical idea of the present invention, and the present invention is not limited to these.

  The light emitting device of the present invention includes, for example, a base 11, a semiconductor light emitting element 12, a reflecting member 13, a phosphor layer 14, and a sealing member as shown in FIGS. 1 (A) to 1 (C). 15.

(Substrate 11, 71)
For example, as shown in FIGS. 10A and 10B and FIGS. 11A and 11B, the bases 11 and 71 include base insulating parts 11a and 71a and base conductive parts 11b and 71b.
The base insulating portions 11a and 71a have concave portions 11c and 71c on their surfaces, and the convex portions 11d and 71d are arranged at the centers of the concave portions 11c and 71c. In other words, the concave portions 11c and 71c are provided around the convex portions 11c and 71c. The semiconductor light emitting element 12 is mounted on the convex portions 11d and 71d.

The shape of the convex portions 11d and 71d is not particularly limited. For example, the planar shape of the upper surface of the convex portion is usually preferably the shape of the semiconductor light emitting element and the shape approximate thereto. For example, a generally quadrangle is generally used, but various shapes such as a polygon, a substantially circle, and a shape having a notch in these shapes can be used.
The vertical cross-sectional shape of the convex portion may be a quadrangle, a narrow or wide trapezoidal shape upward, or the like, and the portion corresponding to the side surface may have a curved surface. The size of the upper surface of the convex portion is preferably equal to or smaller than that of the semiconductor light emitting device. Here, “same as a semiconductor element” means that the semiconductor light emitting element is entirely covered with the phosphor, but depending on the particle size of the phosphor contained in the phosphor layer described later, this phosphor However, the upper surface of the convex portion is allowed to be slightly larger than the semiconductor element to the extent that it is not disposed on the upper surface of the convex portion. Further, depending on the particle size of the phosphor, even if the phosphor is placed on the upper surface of the convex portion, as described later, if the phosphor layer of the semiconductor element is not buried in the phosphor, the phosphor having such a particle size is used. Large enough to allow the body to be placed. For example, “equivalent to a semiconductor light emitting device” includes a size that is 50 μm larger than the outer shape of the semiconductor device. As a result, the light emitting layer of the semiconductor light emitting element is not buried in the phosphor, and light absorption by the base insulating portion can be avoided. In particular, by making the upper surface of the convex portion smaller than the semiconductor light emitting element, a reflecting member to be described later can be disposed even closer to the semiconductor light emitting element, thereby further improving the light extraction efficiency and light quality. it can.
Moreover, it is preferable that the upper surface of a convex part is a flat surface and is substantially parallel with the bottom face of a recessed part.
The height of the convex portion is not particularly limited, but is preferably equal to the depth of the concave portion in consideration of the directivity of light from the semiconductor light emitting element. Here, “equivalent” means that a depth of the recess of about ± 200 μm is allowed.

The material of the base insulating portions 11a and 71a is not particularly limited, and examples thereof include glass epoxy resin, ceramics, glass, and resin. In particular, as the ceramic, alumina, aluminum nitride, mullite, silicon carbide, silicon nitride, or the like is preferable. Examples of the resin include thermoplastic resins such as PPA (polyphthalamide), PPS (polyphenylene sulfide), liquid crystal polymer, and nylon. Thermosetting resins include epoxy resins, silicone resins, modified epoxy resins, modified silicone resins, and urethanes. Examples thereof include resins and acrylate resins. In this case, examples of the base insulating portions 11a and 71a described later include those formed by resin insert molding using a metal member that becomes a pair of positive and negative base conductive portions 11b and 71b.
The bases 11 and 71 are preferably substantially plate-shaped, rectangular parallelepiped, or cubic members when the above-described recesses are ignored.

The base conductive portions 11b and 71b are partly embedded in the base insulating portion 11a, and are exposed at least on the bottom surface of the recess 11c, preferably on the bottom surface and the back surface of the light emitting device. Is something that can be done. Usually, in order to energize a semiconductor light emitting element, optionally a protective element, etc., it is connected to the electrodes of these elements and functions as a terminal.
As shown in FIGS. 10A and 11A, the base body conductive portions 11ba, 71ba, and 71bc may be arranged on the surface of the convex portion in the base portion recess. In this case, the base conductive portion 11ba is independent on the surface of the convex portion 11d and may not be electrically connected to the base conductive portion, or another base conductive portion inside or on the side of the convex portion 71d and the base insulating portion 71a. It may be connected to 71bd and may have a base conductive portion 71b exposed on the bottom surface of the recess 71c and the back surface side of the light emitting device.
The convex portions 11d and 71d may be integrally formed by the same member as the base insulating portions 11a and 71a, and the convex portions 11d and 71d are formed as separate bodies on the base insulating portions 11a and 71a. It may be installed.
For example, the protrusions 11d and 71d are used as a member that can form a fine light-emitting element placement pattern (for example, for flip-chip mounting of the light-emitting element) or as a submount member having various functions such as a Zener diode. May be.

The base conductive portion can be formed of a material containing a metal or an alloy such as copper, aluminum, gold, silver, tungsten, iron, nickel, cobalt, and molybdenum, and may be either a single layer or a laminated structure. The base conductive portion may not necessarily be formed of the same material as a whole, and may be a partially different material or the like. Regardless of whether or not the base conductive portion is exposed from the base insulating portion, it is not necessary to apply plating with silver or the like in consideration of light reflectivity as in the conventional case. This is because a reflection member described later is disposed in the recess. Thus, since it does not rely on plating or the like with a metal film having low weather resistance, a light-emitting device with high life resistance can be formed.
The planar shape in the recesses of the base body conductive portions 11b and 71b and the exposed shape on the back surface are not particularly limited, and can be appropriately determined in consideration of the shape of the light emitting device, the arrangement of the light emitting elements, the space where the light can be arranged, and the like.

(Semiconductor light emitting element 12)
The semiconductor light emitting element 12 is placed on the convex portion 11 d in the concave portion 11 c of the base 11.
The semiconductor light emitting element may be any element as long as it is a so-called light emitting diode (hereinafter sometimes referred to as “light emitting element”). For example, a laminated structure including a light emitting layer is formed on a substrate by various semiconductors such as nitride semiconductors such as InN, AlN, GaN, InGaN, AlGaN, InGaAlN, III-V group compound semiconductors, II-VI group compound semiconductors. What was formed is mentioned.

As a substrate, an insulating substrate such as sapphire or spinel (MgA1 ₂ O ₄ ) having any one of C-plane, A-plane, and R-plane as a main surface, silicon carbide (6H, 4H, 3C), silicon, ZnS, ZnO , GaAs, diamond, etc .; oxide substrates such as lithium niobate and neodymium gallate; nitride semiconductor substrates (GaN, AlN, etc.) and the like. Alternatively, the substrate can be peeled off and only the semiconductor layer can be used as the semiconductor light emitting element 12.
Examples of the semiconductor structure include a homostructure such as a MIS junction, a PIN junction, and a PN junction, a hetero bond, and a double hetero bond.
Each semiconductor layer constituting the light emitting element may be doped with a donor impurity such as Si and Ge and / or an acceptor impurity such as Zn and Mg.
The light emitting layer may have a single quantum well structure or a multiple quantum well structure formed in a thin film in which a quantum effect occurs.

  The emission wavelength of the light-emitting element varies from not only visible light but also ultraviolet to infrared by changing the semiconductor material, mixed crystal ratio, InGaN In content in the light-emitting layer, and the type of impurities doped in the light-emitting layer. Can vary up to.

  As described above, the light emitting element is placed on the convex portion 11 d in the concave portion 11 c of the base 11. In order to place the light emitting element on the convex portion 11d, a joining member is usually used. For example, when it is not necessary to use a conductive bonding member such as an insulating substrate as a bonding surface, an epoxy resin, a silicone resin, or the like can be used. In consideration of deterioration due to light and heat from the light emitting element, the back surface of the light emitting element may be plated with metal such as Al or Ag, or even if it is not necessary to use a conductive bonding member. May be used, and solder such as Au—Sn eutectic and brazing material such as low melting point metal may be used.

The light-emitting element is electrically connected to the bonding surface when a pair of electrodes are formed on different surfaces (both sides with respect to the substrate) or when a pair of electrodes are formed on the same surface (the same surface with respect to the substrate). When it is necessary to make a simple connection, the electrode of the light emitting element may be connected to the base conductive portion 11b disposed on the convex portion 11d by a conductive paste such as silver, gold, or palladium.
When an electrical connection is established from the upper surface side of the light emitting element when the light emitting element is mounted, the electrode of the light emitting element and the base conductive portion 11b are wire-bonded with a conductive wire.

  As the conductive wire, it is preferable that the ohmic property with the electrode of the light-emitting element is good, the mechanical connectivity is good, or the electrical conductivity and thermal conductivity are good. Considering workability and the like, the diameter of the conductive wire is preferably about 10 μm to 45 μm. Examples of such conductive wires include metals such as gold, copper, platinum, and aluminum, and alloys thereof.

(Reflection member 13)
The reflection member 13 is disposed in the recess 11 c of the base body 11.
The material constituting the reflecting member 13 is not particularly limited, and light having a wavelength emitted from the light emitting element is 50% or more, 60% or more, preferably 70% or more, 80% or more, more preferably 90%. This is a material that can be reflected. In addition, a member that hardly transmits or absorbs light from the light emitting element is preferable.
Since the reflecting member 13 may come into contact with the base conductive portion 11b exposed on the bottom surface of the concave portion 11c of the base 11, it is preferably an insulating material. Moreover, the thing with a small difference of a linear expansion coefficient with the base | substrate 11, the base | substrate conductive part 11b, etc. is preferable.

As the reflecting member, for example, a resin in which powder such as a member that can reflect light is dispersed can be used. Examples of the resin include a thermosetting resin, a thermoplastic resin, and the like, specifically, phenol resin, epoxy resin, BT resin, PPA, silicone resin, and the like. A member (for example, TiO ₂ , Al ₂ O ₃ , ZrO ₂ , MgO) which hardly absorbs light from the light emitting element and can reflect light having a large refractive index difference with respect to the base resin. ) And the like can be dispersed to efficiently reflect light.
These materials may be used alone or in combination of two or more. Thereby, the light transmittance can be adjusted, and the linear expansion coefficient of the resin can be adjusted.

  The reflecting member 13 is disposed so as to cover the inner surface of the concave portion 11c of the base 11 and the side surface of the convex portion 11d. Moreover, although the reflection member 13 may be located in the bottom face side from the upper surface of the convex part 11d in the outer edge of the convex part 11d, it is preferable to arrange | position at the height equivalent to the upper surface of the convex part 11d. Thereby, it is possible to minimize the light emitted from the light emitting element from being absorbed by the base insulating portion 11a. The reflection member 13 may have a flat upper surface between the outer edge of the concave portion 11c and the outer edge of the convex portion 11d, but may have a convex curved surface on the bottom surface side. preferable. That is, it is preferable that the upper surface of the reflecting member 13 is recessed. With such a shape, the phosphor layer, which will be described later, is likely to be unevenly distributed around the recessed portion, and the phosphor layer can be more efficiently irradiated with light emitted laterally or downward from the light emitting element. it can. Further, the surface area on which the phosphor is placed can be increased.

The reflective member can be disposed in the recess 11c using a method known in the art such as, for example, discharging a liquid resin from a resin discharge device.
The thickness of the light-reflecting member may be at least enough to cover the base insulating portion 11a with an ultrathin film at the minimum part (that is, the part convex to the bottom surface side), and at least about 30 μm at the minimum part. It preferably has a thickness. Thereby, light absorption by the base insulating part 11a can be suppressed, and light can be extracted efficiently. Although it depends on the depth of the recess 11c, the light can be reflected more efficiently if it is more preferably about 50 to 100 μm.

(Phosphor layer 14)
A phosphor layer 14 is disposed on the reflecting member 13.
The phosphor may be one that converts light from the semiconductor light-emitting element to a shorter wavelength, but one that converts light to a longer wavelength from the viewpoint of light extraction efficiency is preferable.

Examples of the phosphor include nitride-based phosphors / oxynitride-based phosphors mainly activated by lanthanoid elements such as Eu and Ce, and more specifically, Eu-activated α or β sialon type fluorescence. Bodies, various alkaline earth metal nitride silicate phosphors, lanthanoid elements such as Eu, alkaline earth metal halogenapatite phosphors mainly activated by transition metal elements such as Mn, alkaline earth halosilicate fluorescence Body, alkaline earth metal silicate phosphor, alkaline earth metal halogen borate phosphor, alkaline earth metal aluminate phosphor, alkaline earth metal silicate, alkaline earth metal sulfide, alkaline earth metal thiogallate Rare earth aluminates, rare earth silicates mainly activated by lanthanoid elements such as alkaline earth metal silicon nitride, germanate, Ce Examples thereof include organic substances and organic complexes mainly activated by lanthanoid elements such as Eu. Moreover, it is fluorescent substance other than the said fluorescent substance, Comprising: The fluorescent substance which has the same performance and effect can also be used.
The shape of the phosphor is preferably, for example, a spherical shape or a shape similar to this, and more preferably has a particle size of about 1 to 100 μm, about 5 to 50 μm, and further about 10 to 20 μm.

  Phosphor is a single layer containing one kind of phosphor, a single layer in which two or more kinds of phosphors are mixed, two or more layers in which two or more kinds of phosphors are contained in separate layers, two kinds Any one of two or more single layers in which the above-described fluorescent substances are mixed may be used. In other words, the phosphor layer may be formed as a laminated structure in which the phosphor, the material, or the type or amount of additives described later are different.

The phosphor layer is preferably composed of a phosphor and a translucent resin.
Here, the light-transmitting resin is preferably a light-transmitting resin with respect to light from the light-emitting element and having light resistance and insulating properties. Specifically, silicone resin composition, modified silicone resin composition, epoxy resin composition, modified epoxy resin composition, acrylic resin composition, etc., silicone resin, epoxy resin, urea resin, fluororesin, and at least these resins An organic substance such as a hybrid resin containing one or more kinds can be given.
Here, the translucency means a property of transmitting light emitted from the light emitting element to about 70% or more, about 80% or more, about 90% or more, or about 95% or more.

The phosphor layer is preferably formed on both the curved surface of the reflecting member and the upper surface of the light emitting element.
For example, in the case of a light-emitting element that emits blue light and a light-emitting device that converts white light from the light-emitting element into yellow light and extracts blue light by mixing blue light and yellow light, blue light emitted from the top surface of the light-emitting element A phosphor layer for converting the wavelength of the light is useful on the upper surface of the light emitting element. In addition, the phosphor layer formed on the curved surface of the reflector is useful for wavelength conversion of blue light emitted from the side surface of the light emitting element.
The light from the light-emitting element passes through the phosphor layer and excites the phosphor (hereinafter also referred to as “transmission excitation light”), whereas the latter causes phosphor excitation on the surface of the phosphor layer. (Hereinafter also referred to as “surface excitation light”).
Like the former, in the excitation method which permeate | transmits a fluorescent substance layer, since the fluorescent substance itself has light absorption, the loss of excitation arises. On the other hand, when excitation is performed on the surface of the phosphor layer as in the latter case, light absorption of the phosphor itself can be suppressed. That is, the higher the rate of excitation on the phosphor layer surface, the higher the light emission efficiency of the light emitting device.
In the light emitting device according to this embodiment, the upper surface of the convex portion is set to be equal to or smaller than that of the semiconductor light emitting element, so that the light emitting layer exposed on the side surface of the light emitting element is surely exposed from the phosphor layer. Can do. In addition, since many phosphors are arranged below the light emitting element, light from the light emitting element can be extracted as surface excitation light instead of transmission excitation light, and luminous efficiency can be increased. .
When the phosphor layer is composed of a phosphor and a translucent resin, for example, the phosphor layer can be formed by a method known in the art. Especially, it is preferable that a fluorescent substance layer is formed on the reflection member by the method of depositing fluorescent substance using potting. Thereby, the phosphor is unevenly distributed on the reflecting member side in the translucent resin, and as described above, the phosphor layer is more efficiently irradiated with the light emitted from the light emitting element in the lateral direction or downward. Can be made.

  In addition to the phosphor, the phosphor layer may contain additives such as a colorant, a light diffusing agent, a light reflecting material, and various fillers.

(Sealing member 15)
The light emitting device of the present invention includes a sealing member that covers the light emitting element. This sealing member is preferably formed of a light-transmitting material such as the light-transmitting resin described above.
The shape is not particularly limited, but it is preferably disposed only above the concave portion of the base. That is, normally, since the outer periphery of the light emitting element is surrounded in a wall shape by the concave portion of the base insulating portion, the sealing member is on the reflecting member and the phosphor layer and is embedded in the concave portion. Is arranged.
In consideration of the light distribution characteristics and the like, for example, the plate shape and the upper surface may have a convex lens shape, a concave lens shape, a Fresnel lens shape, or the like, or a lens-shaped member may be provided separately. Since the reflecting member is arranged up to the end portion on the bottom surface side of the lens shape, the light propagating through the lens is not absorbed by the substrate, and the light extraction efficiency can be further improved.

(Other parts)
The light emitting device of the present invention is provided with various components such as a protective element and a lens member in order to efficiently extract light from the light emitting element and to ensure the characteristics and / or reliability. It may be.
In particular, as shown in FIGS. 4 to 6, when a lens is formed on the concave portion of the substrate with a resin having high light transmittance, the lens is applied only on the phosphor layer by, for example, a potting method. However, this not only improves the light extraction due to the lens effect, but also prevents the lens from coming into contact with the substrate and prevents light absorption into the substrate. In addition, by making the phosphor layer and the lens into two layers, a resin (for example, a resin having a low viscosity) that easily settles the phosphor is used on the inside, and the lens is made of a resin having a high viscosity in order to have a lens shape. For example, a material suitable for each layer can be used.

(Protective element)
The protective element is not particularly limited, and may be any known element mounted on the light emitting device. For example, an element capable of short-circuiting a reverse voltage applied to the light-emitting element or short-circuiting a forward voltage higher than a predetermined voltage higher than the operating voltage of the light-emitting element, that is, overheating, overvoltage, overcurrent , Protection circuits, electrostatic protection elements and the like. Specifically, a Zener diode, a transistor diode, or the like can be used.
In the light emitting device of the present invention, the protective element is preferably placed outside the irradiation range of the light emitted from the light emitting element, for example, in the light reflective member. Thereby, the light absorption in a protection element can be suppressed.
Normally, only one protective element is mounted, but two or more protective elements may be mounted.

In addition, the method for manufacturing the light emitting device of the present invention includes:
(A) A base insulating portion having a concave portion on the surface and a base conductive portion that is partially embedded in the base insulating portion and exposed at least on the back surface of the concave portion, and an upper surface of the convex portion of the base having a convex portion at the center of the concave portion A semiconductor light emitting element having a plane area equal to or larger than the area of the upper surface of the convex part,
(B) electrically connecting the semiconductor light emitting element to the base conductive portion;
(C) filling a reflective member into a concave portion surrounding the convex portion of the base, and covering the reflective member with the inner surface of the concave portion and the side surface of the convex portion;
(D) A phosphor layer material containing a phosphor is applied by a potting method, and the phosphor is disposed on the reflecting member.

In particular, in the steps (a) and (b), as described above, the light emitting element is bonded to the upper surface of the convex portion of the base by the above-described material such as a metal eutectic bonding method, a resin bonding material, or the like. The substrate conductor is electrically connected by a method.
In the step (c), it is preferable to intentionally form the concave portion so that the outer edge of the reflecting member is disposed at a position equivalent to the upper surface of the convex portion of the base. The formation of the recesses here is, for example, by applying a reflective member having a volume smaller than the volume of the substrate recesses, so that the reflection member preferentially rises along the walls of the substrate recesses by capillarity. The reflecting member can be concave. Further, the concave portion of the reflecting member can be adjusted by the viscosity of the reflecting member and the wettability of the reflecting member to the material of the substrate concave portion.
Thus, by disposing the reflecting member around the semiconductor light emitting element, it is possible to prevent light from the light emitting element from being absorbed by the substrate.
In the step (d), a potting method is adopted. At this time, the phosphor layer material is applied only on the semiconductor light emitting element and the reflecting member. In addition, the phosphor can be settled to the lower layer of the phosphor layer by allowing time to cure the phosphor layer material. As a result, most of the phosphor is positioned below the semiconductor light emitting element, so that the semiconductor light emitting element is not buried with the phosphor. Moreover, the recessed part of a reflection member can increase the surface area where a fluorescent substance is arrange | positioned. Therefore, even in a small light emitting device, a large number of phosphors can be arranged on the irradiation surface of light emitted from the semiconductor light emitting element. The more efficient the light emission to the phosphor of the present invention can be realized with a light emitting device that requires light and has a color tone with a lower color temperature.
Below, the light-emitting device of this invention is demonstrated in detail based on drawing.

<Embodiment 1>
As shown in FIGS. 1A to 1C, the light emitting device 10 of this embodiment includes a base body 11, a semiconductor light emitting element 12, a reflecting member 13, a phosphor layer 14, and a sealing member 15. Prepare.
As shown in FIGS. 10A to 10D, the base 11 includes a base insulating part 11a made of alumina ceramics and a base conductive part 11b made of tungsten.
The base insulating portion 11a has a concave portion 11c having a depth of about 100 to 500 μm on its surface, and a convex portion 11d whose upper surface is substantially equivalent to the depth of the concave portion 11c at the center of the concave portion 11c. Has been placed. The semiconductor light emitting element 12 is mounted on the convex portion 11d in the concave portion 11c. The area of the upper surface of the convex portion 11 d substantially matches the area of the semiconductor light emitting element 12.
A portion of the base conductive portion 11b is embedded in the base insulating portion 11a, and is exposed separately as a pair on the bottom surface of the recess 11c and the back surface of the base 11 to connect the semiconductor light emitting element 12 and the outside. Functions as a terminal. Although not shown in FIG. 1B, the base conductive portion 11ba having the same size as the upper surface of the convex portion 11d is formed on the upper surface of the convex portion 11d.
The semiconductor light emitting element 12 is a light emitting element in which a nitride semiconductor is laminated on an insulating substrate, and a pair of electrodes exposed on the upper surface of the light emitting element and a bottom surface of the recess 11c of the base insulating part 11a by wires 16. The base body conductive portion 11b is electrically connected.

The reflecting member 13 is made of a silicone resin (TiO ₂ concentration: about 0.3 g / cm ³ ) containing TiO ₂ (average particle diameter: about 0.26 μm), and other than the region where the convex portion 11d is formed. The upper surface of the concave portion 11c is arranged in a shape that forms a convex curved surface on the bottom surface side so as to substantially completely cover the inner surface of the concave portion 11c (that is, the bottom surface, the inner side surface, and the side surface of the convex portion). The minimum film thickness of the reflecting member 13 is about 50 μm, and the maximum film thickness is equal to the height of the convex portion 11 d and is about 500 μm.
The reflecting member 13 is located at the same height as the upper surface of the convex portion 11d at the outer edge of the convex portion 11d.
In order to form the reflecting member 13 as described above, the material constituting the reflecting member, that is, the viscosity of the resin is adjusted, and the surface tension caused by the height of the concave and convex portions and the outer edge of the base described above. The recess is filled with resin so that the maximum can be exhibited.

A phosphor layer 14 is disposed on the reflecting member 13. Here, the phosphor layer 14 is made of a phosphor (for example, YAG, particle size of about 10 to 20 μm) and a translucent resin (for example, a silicone resin), and the phosphor is in the translucent resin on the reflecting member side. Is unevenly distributed.
That is, the phosphor layer is formed by potting a translucent resin containing a phosphor, and the phosphor can settle to the lower layer of the phosphor layer by allowing time for this resin to cure. In addition, the reflecting member 13 is disposed so as to sink immediately above the entire upper surface of the reflecting member 13. In addition, the semiconductor light-emitting element 12 is also disposed so as to sink immediately above the entire top surface of the semiconductor light-emitting element 12. At this time, the light emitting layer exposed on the side surface of the light emitting element is exposed from the portion where the phosphor is set and disposed.

  The semiconductor light emitting element 12, the wire 16, and the phosphor layer 14 are covered with a sealing member 15 made of silicone resin. The planar shape of the sealing member 15 on the base body 11 side matches the planar shape of the concave portion 11c of the base insulating portion 11a, and is disposed only above the concave portion 11c. The sealing member 15 is formed by resin potting, and is formed into a convex shape by surface tension.

By having such a configuration, light excited by the phosphor in the vicinity of the upper surface of the light emitting element is suppressed from being absorbed by excess phosphor in the process of passing through the sealing member. Transmission-type excitation light from the body can be extracted more effectively, and light extraction efficiency can be improved.
In addition, since the light emitting layer can be exposed from the phosphor layer without the light emitting layer of the semiconductor light emitting element being embedded in the phosphor layer, surface excitation light from the phosphor can be extracted more effectively, and more light is emitted. The extraction efficiency can be improved.
Since the base to which the light emitted from the semiconductor light emitting element hits is almost entirely covered with the reflecting member, light loss due to the base material can be avoided.
Furthermore, since the upper surface of the reflecting member has a convex curved surface on the bottom surface side of the concave portion, more phosphor can be unevenly distributed in the vicinity of the semiconductor light emitting element, and the phosphor is present on the upper surface of the reflecting member. By being unevenly distributed, the distance between the emitted light from the light emitting element and the phosphor can be made somewhat equal in the vicinity of the semiconductor light emitting element, so that the emitted light can be efficiently irradiated to the phosphor, and the amount of phosphor can be reduced. Can be reduced. As a result, the emitted light can be excited with the fluorescent material to the maximum, and the absorption of the emitted light by the fluorescent material can be minimized, thereby further improving the light extraction efficiency.

  In addition, the above-described method for manufacturing a light emitting device can easily manufacture a light emitting device with high light extraction efficiency easily.

<Embodiment 2>
As shown in FIGS. 2A to 2C, the light emitting device 20 of this embodiment includes a base 11, a semiconductor light emitting element 12, a reflecting member 13, a phosphor layer 24, and a sealing member 15. Prepare.
In the light emitting device 20, the phosphor in the phosphor layer 24 is formed in substantially the same manner as the light emitting device 10 of Embodiment 1 except that the phosphor is unevenly distributed only near the bottom of the concave portion on the upper surface of the reflecting member 14. .
In order to make the phosphor unevenly distributed only in the vicinity of the bottom of the concave portion, there is a method in which the viscosity of the resin constituting the phosphor layer is set slightly lower to further promote the sedimentation of the phosphor.
Thus, the phosphor is unevenly distributed in the vicinity of the bottom of the concave portion of the reflecting member, so that the color temperature of the light toward the side surface of the light emitting device can be increased.
When a white light emitting device is manufactured by filling a cavity having a flat bottom surface with a phosphor-containing resin by a potting method, the fluorescent material is positioned on the top surface of the light emitting element and the flat bottom surface of the cavity. At this time, the light in the direction in which the viewing angle of the light emitting device is small appears to be white by combining the blue light from the light emitting element and the yellow light by phosphor excitation, but when the viewing angle increases, the light is emitted by the cavity wall surface. The angle at which the element is hidden is formed, that is, blue light is blocked and the color temperature is extremely lowered.
On the other hand, in the present light emitting device, the phosphor is unevenly distributed on the bottom surface of the concave portion of the reflecting member, so that when the viewing angle is increased, the phosphor layer is concealed by the wall surface of the cavity. That is, yellow light is blocked and the color temperature is increased. In this way, it is possible to suppress the color temperature from becoming extremely low even in the direction where the viewing angle is large.

<Embodiment 3>
As shown in FIGS. 3A to 3C, the light emitting device 30 of this embodiment includes a base 11, a semiconductor light emitting element 12, a reflecting member 13, a phosphor layer 34, and a sealing member 15. Prepare.
In the light emitting device 30, the phosphor in the phosphor layer 34 is substantially the same as the light emitting device 10 of Embodiment 1 except that the phosphor is unevenly distributed only in the vicinity of the bottom of the concave portion on the upper surface of the reflecting member 14 and the inner periphery thereof. Is formed.
In order to make the phosphor unevenly distributed only in the vicinity of the bottom of the recess and the inner periphery thereof, there is a method in which the viscosity of the resin constituting the phosphor layer is set high and potting is performed on the light emitting element (center portion). .
As described above, the phosphor is unevenly distributed near the bottom of the concave portion of the reflecting member, so that the light emitting surface can be reduced and the luminance can be improved. Further, by reducing the light emitting surface, it becomes possible to facilitate the operation of light, such as when condensing light with a secondary optical component.

<Embodiment 4>
As shown in FIGS. 4A to 4C, the light emitting device 40 of this embodiment includes a base 11, a semiconductor light emitting element 12, a reflecting member 13, a phosphor layer 14, a sealing member 15, And a lens 17.
In the light emitting device 40, the lens 17 is formed in substantially the same manner as the light emitting device 10 of Embodiment 1 except that the lens 17 is disposed above the sealing member 15.
Such a light emitting device has the same effect as that of the first embodiment, and can impart desired directivity to the light from the light emitting element by the lens 17.

<Embodiment 5>
As shown in FIGS. 5A to 5C, the light emitting device 50 according to this embodiment includes a base 11, a semiconductor light emitting element 12, a reflecting member 13, a phosphor layer 24, a sealing member 15, And a lens 17.
In the light emitting device 50, the lens 17 is formed in substantially the same manner as the light emitting device 20 of Embodiment 2 except that the lens 17 is disposed above the sealing member 15.
Such a light emitting device has the same effect as that of the second embodiment, and can impart desired directivity to the light from the light emitting element by the lens 17.

<Embodiment 6>
As shown in FIGS. 6A to 6C, the light emitting device 60 of this embodiment includes a base 11, a semiconductor light emitting element 12, a reflecting member 13, a phosphor layer 34, a sealing member 15, And a lens 17.
In the light emitting device 60, the lens 17 is formed in substantially the same manner as the light emitting device 30 of Embodiment 3 except that the lens 17 is disposed above the sealing member 15.
Such a light emitting device has the same effect as that of the second embodiment, and can impart desired directivity to the light from the light emitting element by the lens 17.

<Embodiment 7>
As shown in FIGS. 7A to 7C, the light emitting device 70 of this embodiment includes a base 71, a semiconductor light emitting element 12, a reflecting member 13, a phosphor layer 14, a sealing member 15, A lens 17 is provided.
As shown in FIGS. 11A and 11B, the base body 71 is formed by separating the base conductive portion 71ba (see FIG. 11A) into two on the upper surface of the convex portion 71d in the concave portion 71c. The substrate conductive portion 71ba is connected to the substrate conductive portion 71bb passing through the inside of the convex portion, connected to the substrate conductive portion 71b exposed at the bottom surface of the concave portion 11c, and substantially exposed except on the back surface of the substrate insulating portion 71a. Further, it is formed in the same manner as the base 11 in the first embodiment.

The semiconductor light emitting element 12 has a pair of electrodes (not shown) formed on the surface thereof electrically connected to the pair of base body conductive portions 11ba on the upper surface of the convex portion 71d.
Such a light emitting device has the same effects as those of the first and fourth embodiments.

<Eighth embodiment>
As shown in FIGS. 8A to 8C, the light emitting device 80 of this embodiment includes a base 71, a semiconductor light emitting element 12, a reflecting member 13, a phosphor layer 14, a sealing member 15, A lens 17 is provided.
The light emitting device 80 is formed in substantially the same manner as the light emitting device 50 of the fifth embodiment, except that the base conductive portion 71bb is disposed in the convex portion 71d of the base 71.
Such a light emitting device has the same effects as those of the second and fifth embodiments.

<Embodiment 9>
As shown in FIGS. 9A to 9C, the light emitting device 90 of this embodiment includes a base 71, a semiconductor light emitting element 12, a reflecting member 13, a phosphor layer 14, a sealing member 15, A lens 17 is provided.
The light emitting device 90 is formed in substantially the same manner as the light emitting device 60 of Embodiment 6 except that the base conductive portion 71bb is disposed in the convex portion 71d of the base 71.
Such a light emitting device has the same effects as those of the third and sixth embodiments.

The light-emitting device of the present invention can be a light-emitting device capable of reducing light absorption and increasing output, and various display devices, lighting fixtures, displays, backlight light sources for liquid crystal displays, as well as facsimiles and copiers. It can be used for a wide range of applications such as an image reading device in a scanner, a projector device, and the like.
Moreover, in the manufacturing method of the light-emitting device of this invention, the light-emitting device mentioned above can be manufactured simply and reliably.

10, 20, 30, 40, 50, 60, 70, 80, 90 Light-emitting device 11, 71 Base 11a, 71a Base insulating part 11b, 11ba, 71b, 71ba, 71bc, 71bd Base conductive part 11c, 71c Recess 11d, 71d Convex part 12 Semiconductor light emitting element 13 Reflective member 14, 24, 34 Phosphor layer 15 Sealing member 16 Wire 17 Lens

Claims (11)

A base body comprising a base body conductive portion that has a concave portion on the surface and a base conductive portion that is partially embedded in the base insulating portion and exposed at least on the back surface of the concave portion;
A semiconductor light emitting device;
A reflective member disposed in the recess;
A phosphor layer disposed on the reflecting member;
A sealing member that covers the semiconductor light emitting element,
The concave portion has a convex portion having an upper surface equal to or smaller than the semiconductor light emitting element at the center thereof, and the semiconductor light emitting element is placed on the convex portion,
The reflection member covers the inner surface of the concave portion and the side surface of the convex portion.   The light emitting device according to claim 1, wherein the convex portion has a height equivalent to a depth of the concave portion.   3. The light emitting device according to claim 1, wherein the reflecting member is located on the outer edge of the convex portion at a position equal to or closer to the bottom surface than the upper surface of the convex portion.   The light emitting device according to any one of claims 1 to 3, wherein the reflecting member has a curved surface convex toward the bottom surface between the outer edge of the concave portion and the outer edge of the convex portion.   The light emitting device according to claim 4, wherein the phosphor layer is formed on a curved surface of the reflecting member and on an upper surface of the semiconductor light emitting element.   The phosphor layer includes a phosphor and a translucent resin, and the phosphor is unevenly distributed on the reflecting member side in the translucent resin. The light-emitting device of description.   The light emitting device according to claim 1, wherein the sealing member is disposed only above the concave portion of the base body. (A) A base insulating portion having a concave portion on the surface and a base conductive portion that is partially embedded in the base insulating portion and exposed at least on the back surface of the concave portion, and an upper surface of the convex portion of the base having a convex portion at the center of the concave portion A semiconductor light emitting element having a plane area equal to or larger than the area of the upper surface of the convex part,
(B) electrically connecting the semiconductor light emitting element to the base conductive portion;
(C) filling a reflective member into a concave portion surrounding the convex portion of the base, and covering the reflective member with the inner surface of the concave portion and the side surface of the convex portion;
(D) A method for manufacturing a light emitting device, wherein a phosphor layer material containing a phosphor is applied by a potting method, and the phosphor is disposed on the reflecting member.   The manufacturing method of the light-emitting device according to claim 8, wherein the reflecting member is disposed on the outer edge of the convex portion at a position equal to or closer to the bottom surface than the top surface of the convex portion.   10. The method of manufacturing a light emitting device according to claim 8, wherein the reflecting member is formed such that a top surface of the reflecting member has a curved surface convex toward the bottom surface between the outer edge of the concave portion and the outer edge of the convex portion.   The said fluorescent substance layer has fluorescent substance and translucent resin, The said fluorescent substance is unevenly distributed to the reflective member side in the said translucent resin, It is any one of Claims 8-10. Manufacturing method of light-emitting device.

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