JP2007042668A - Led light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED light emitting device which has high light take-out efficiency, can stably maintain high light take-out efficiency for long time, can be manufactured with high yield and has superior reliability. <P>SOLUTION: In the LED light emitting device, an LED chip is loaded in a recess arranged in a substrate made from white resin. A substrate inner peripheral face surrounding the LED chip is covered with a resin layer comprising a filler of light reflectivity. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an LED light emitting device using an LED chip as a light source.

Various improvements have been attempted in LED light emitting devices having a basic structure in which an LED chip is surrounded by a substrate (exterior resin). In particular, improving the light extraction efficiency is directly related to the improvement in luminous intensity, which is the basic performance of the light emitting device, and can be said to be the greatest problem.
In general, the light extraction rate can be increased by forming the substrate with a white resin having a high light reflectance. However, as a result of exposure to the light from the LED chip, the reflector surface (surface facing the LED chip) of the substrate deteriorates (discolors) and cannot maintain a stable reflectance over a long period of time. As a result, the light extraction rate gradually decreases, causing a decrease in light intensity over time. In particular, when an LED chip that emits light on a short wavelength side, such as a blue light emitting LED chip or an ultraviolet light emitting LED chip, is used, the degree of deterioration of the reflector surface is large, and the problem of a decrease in luminous intensity becomes significant.
As a method for improving the light extraction efficiency, it has also been proposed to form a metal layer having a high light reflectance on the reflector surface of the substrate (see, for example, Patent Documents 1 and 2). However, when such a metal layer is provided, the LED light-emitting device must be manufactured in consideration of a short circuit problem. In addition, sufficient adhesion between the metal layer and the substrate cannot be obtained, and the metal layer may be peeled off, resulting in a decrease in yield and reliability.

JP 2004-228549 A JP 2004-288657 A

  In view of the above-described conventional problems, an object of the present invention is to provide an LED light emitting device that has high light extraction efficiency and can stably maintain high light extraction efficiency over a long period of time. It is another object of the present invention to provide an LED light-emitting device that can be manufactured with a high yield and has excellent reliability.

In order to solve the above problems, the present invention has the following configuration. That is,
An LED chip;
A substrate made of a white resin, the substrate including a portion surrounding the LED chip;
A resin layer containing a light reflective filler, the resin layer covering the inner peripheral surface of the portion of the substrate;
A sealing member filled in a space surrounded by the resin layer so as to cover the LED chip;
It is an LED light-emitting device provided with.

In the above configuration, the light emitted from the LED chip in the lateral direction travels through the sealing member, and then reaches the resin layer containing the light-reflective filler, and receives a reflection action there. That is, the resin layer functions as a main reflecting member. As a result, the amount of light reaching the surface of the substrate facing the LED chip, that is, the inner peripheral surface of the portion surrounding the LED chip is reduced, so that deterioration of the inner peripheral surface can be suppressed. As a result, it is possible to prevent a decrease in light extraction efficiency due to the deterioration of the inner peripheral surface. Because of such an effect, the light emitting device of the present invention has high light extraction efficiency, and can maintain high light extraction efficiency stably over a long period of time.
On the other hand, in the configuration of the present invention, by using the base material of the layer exhibiting the reflection function as the resin, it is possible to ensure good adhesion between the layer and the base material. Therefore, the problem of peeling caused by the conventional configuration in which the metal layer is provided on the surface of the substrate is solved. As described above, the structure of the present invention can be manufactured with a high yield and is a light-emitting device with excellent reliability.

(LED chip)
Although the LED chip which can be used is not particularly limited, an LED chip having a main emission peak wavelength in a wavelength region of 500 nm or less (for example, an LED chip having a main emission peak wavelength in the range of 370 nm to 500 nm) can be preferably used. The LED chip is not limited to an LED chip having a single emission peak, and an LED chip having a plurality of emission peaks can also be used. In addition, when it has a some light emission peak, you may have a 1 or 2 or more light emission peak in the area | region longer than 500 nm.

  In general, the reflectivity of the reflector material currently used for the purpose of reflecting the light emitted from the LED chip in the lateral direction is drastically lowered when the wavelength of the irradiation light is in a short wavelength region. Specifically, the reflectivity of polyphthalamide or the like frequently used as a reflector material shows an exponential decrease as the wavelength of irradiation light becomes shorter at a boundary of about 400 to 430 nm. Therefore, a resin layer described later was used in combination with an LED chip (for example, an LED chip having a main emission peak wavelength of 400 nm or less) that emits light in a wavelength region in which the reflectivity of the reflector material is significantly reduced. In this case, the effect of the resin layer becomes more remarkable.

The configuration of the LED chip is not particularly limited as long as it has the above wavelength characteristics. For example, a semiconductor light emitting device including a light emitting layer made of a group III nitride compound semiconductor can be used as the LED chip in the present invention. Here, in general, a group III nitride compound semiconductor is a general formula of Al _X Ga _Y In _1-XY N (0 ≦ X ≦ 1, 0 ≦ Y ≦ 1, 0 ≦ X + Y ≦ 1). A so-called binary system of AlN, GaN and InN, Al _x Ga _1-x N, Al _x In _1-x N and Ga _x In _1-x N (in the above, 0 <x <1) Includes so-called ternary systems. Part of group III elements may be substituted with boron (B), thallium (Tl), etc., and part of nitrogen (N) may also be phosphorus (P), arsenic (As), antimony (Sb), bismuth. It can be replaced with (Bi) or the like. Moreover, the light emitting layer may contain an arbitrary dopant.

(Substrate)
The base is made of a white resin and includes a portion surrounding the LED chip. The substrate in the present specification includes those composed of a single member and those constituted by combining a plurality of members. As an example of the former, a material in which a specific material is molded into a substantially cup shape so that a concave portion in which an LED chip is to be mounted can be formed on one side. In this case, it is good also as a structure which the lower part (bottom part) of a base | substrate includes the lead frame in which an LED chip is mounted. In other words, in one embodiment of the present invention, a substrate into which a lead frame is inserted is used. On the other hand, as an example of the latter, a resin in which an exterior resin having a ring-shaped inner peripheral surface is placed and bonded on a substrate so as to form a recess in which the LED chip is to be mounted. Can be mentioned.
The recess provided in the base is formed in a cup shape, for example. However, in the present invention, the shape of the concave portion is not limited to the cup shape.

  The material of the substrate is not particularly limited. For example, the substrate can be formed using a polyamide resin (including an aromatic polyamide resin), a liquid crystal polymer, polyphthalamide, nylon 6T, or the like. You may comprise a base | substrate using the material containing a titanium oxide, potassium titanate, a glass fiber, etc.

  It is preferable that the inner peripheral surface (the surface facing the LED chip) of the portion surrounding the LED chip in the substrate (also referred to as “LED surrounding portion” in this specification) be as smooth as possible. In the present invention, the resin layer to be described later functions as a main reflecting member, but usually, a part of the light emitted from the LED chip in the lateral direction and / or a part of the light generated by being reflected by the resin layer is a part of the substrate. It reaches the inner peripheral surface of the LED enclosure. In order to increase the light extraction efficiency by efficiently reflecting such light, it is preferable to increase the reflectance by smoothing the inner peripheral surface of the LED surrounding portion.

(Resin layer)
The inner peripheral surface of the LED surrounding portion of the base is covered with a resin layer. This resin layer contains a light reflective filler and functions as a reflective member. The type of the light reflective filler is not particularly limited, but it is preferable to employ a material having a high light reflectance. For example, titanium oxide, potassium titanate, or the like can be used as the light reflective filler.

  On the other hand, the kind of the base material of the resin layer is not particularly limited, and for example, epoxy resin or silicone (including silicone resin, silicone rubber, and silicone elastomer) can be used. Preferably, the resin layer is composed of silicone as a base material. Silicone has high resistance to light on the short wavelength side. Therefore, particularly when an LED chip that emits light on a short wavelength side (blue light or ultraviolet light) is used, deterioration of the resin layer can be effectively prevented.

  The thickness of the resin layer can be arbitrarily set. The thickness of the resin layer may not be uniform. The thickness of the resin layer may be positively changed. For example, the region closer to the LED chip is thickened so that the surface of the resin layer is inclined with respect to the optical axis of the LED chip (the region closer to the LED chip is closer to the optical axis). A resin layer can be formed. In such a resin layer, light emitted from the LED chip in the lateral direction can be efficiently converted in the light extraction direction on the surface. This improves the light extraction efficiency.

  An example of a resin layer forming method will be described with reference to FIG. First, a base body 100 formed into a cup shape is prepared (FIG. 7a). Next, a mold 1025 having a head substantially similar to the concave portion 101 and having a slightly smaller head is inserted into the concave portion 101 of the base body 100 that surrounds the LED chip, and the tip surface of the head is the bottom of the cup-shaped portion 101. The mold 102 is fixed in close contact with the wall (FIG. 7b). Subsequently, a resin containing a light reflective filler is poured into the gap 103 between the base 100 and the head of the mold tool 102 (FIG. 7b). Thereafter, the resin is solidified (FIG. 7c). When the resin is solidified, the mold 102 is pulled out (FIG. 7d). Through the above steps, the resin layer 105 reflecting the shape and size of the head of the mold 102 used is formed on the inner peripheral surface 104 of the base body 100.

(Sealing member)
The sealing member is a member filled in the space surrounded by the resin layer so as to cover the LED chip, and is mainly provided for the purpose of protecting the LED chip from the external environment. As a material for the sealing member, it is preferable to adopt a material that is transparent to the light of the LED chip and is excellent in durability, weather resistance, and the like. For example, an appropriate material can be selected from silicone (including silicone resin, silicone rubber, and silicone elastomer), epoxy resin, urea resin, glass and the like in relation to the emission wavelength of the LED chip. When the light from the LED chip includes light on the short wavelength side (blue light or ultraviolet light), it is preferable to employ a material having high resistance to the light, such as silicone.

The sealing member can be provided so that a plurality of layers made of different materials are stacked on the LED chip.
A phosphor can also be contained in the sealing member. By using the phosphor, part of the light from the LED chip can be converted into light having a different wavelength, and the emission color of the light emitting device can be changed or corrected. Any phosphor can be used as long as it can be excited by the light of the LED chip, and the light emission color of the light emitting device is considered in the selection. The phosphor may be uniformly dispersed in the sealing member or may be localized in a part of the region. For example, by localizing the phosphor in the vicinity of the LED chip, the light emitted from the LED chip can be efficiently irradiated onto the phosphor.

For example, if it is going to comprise the light-emitting device which can light-emit white light, a blue light-emitting LED chip is employ | adopted as an LED chip, and a yellowish fluorescent substance can be contained in a sealing member. The yellow phosphor for example, the general formula _{Y 3-x Gd x Al 5} -y Ga y O 12: Ce (0 ≦ x ≦ 3,0 ≦ y ≦ 5) yttrium-aluminum-garnet fluorescent represented by The body can be preferably used. Such a phosphor efficiently converts blue light into yellow or yellow-green light. In the above general formula, yttrium (Y) partially or wholly substituted with Lu or La can be used, and aluminum (Al) partially or entirely replaced with In or Sc. You can also.
In addition, as a yellow phosphor, (Ca _0.49 Mg _0.50 ) ₃ (Sc _0.75 Y _0.25 ) ₂ Si ₃ O _12.015 : Ce ³⁺ , (Ca _0.99 ) ₃ Sc ₂ Si ^{_{3 O 12.015: Ce 3+, (}} Ca 0.49 Mg 0.50) 3 (Sc 0.50 Y 0.50) 2 Si 3 O 12.015: Ce 3+, (Ca 0.49 Mg 0.50 ) ₃ (Sc _0.50 Lu _0.50 ) ₂ Si ₃ O _12.015 : Ce ³⁺ , Ba ₂ SiO ₄ : Eu ²⁺ (orthosilicate) and the like can also be used.

The phosphor usable in the present invention is not limited to the above yellow phosphor. Examples of red phosphors, green phosphors, and blue phosphors are shown below.
(Red phosphor)
Examples of red phosphors include Y ₂ O ₃ : Eu, Y ₂ O ₂ S: Eu, (Y, La) O ₃ : Eu, (Ca, Sr) S: Eu, and Y ₂ Al ₅ O ₁₂ : Eu. Y ₃ (Al, Ga) ₅ O ₁₂ : Eu, SrY ₂ S ₄ : Eu, Y ₂ O ₂ S: Eu, Bi, YVO ₄ : Eu, Bi, SrS: Eu, CaLa ₂ S ₄ : Ce, etc. Can be adopted.

(Green phosphor)
Examples of green phosphors include (Y, Ce) ₃ (Al, Ga) ₅ O ₁₂ : Tb, BaMgAl ₁₀ O ₁₇ : Eu, Ba ₂ MgSi ₂ O ₇ : Eu, (Sr, Ca, Ba) (Al _{, Ga) 2 S 4: Eu} , BaSiO 4: Eu, YBO 3: Ce, Tb, (Ca, Sr) p / 2 Si 12-p-q Al p + q O 1-q N: Ce, Ca 8 Mg (SiO ₄ ) ₄ Cl ₂ : Eu, SrAl ₂ O ₄ : Eu, SrAl ₁₄ O ₂₅ : Eu, (Ca _0.99 ) ₃ Sc ₂ Si ₃ O _12.015 : Ce ³⁺ , (Ca _0.49 Zn _0.50 ) ₃ Sc ₂ Si ₃ O _12.15 : Ce ³⁺ can be employed.

(Blue phosphor)
(Ba, Ca, Mg) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ , (Ba, Mg) ₂ Al ₁₆ O ₂₇ : Eu ²⁺ , Ba ₃ MgSi ₂ O ₈ : Eu ²⁺ , BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺ or the like can be used.

A plurality of types of phosphors can be combined and contained in the sealing member. In this case, a phosphor that emits light when excited by light from the LED chip and a phosphor that emits light when excited by light emitted from the phosphor can be used in combination.
By containing a light diffusing material in the sealing member, it is possible to promote light diffusion in the sealing member and reduce light emission unevenness. In particular, in the configuration using the phosphor as described above, it is preferable to use such a light diffusing material in order to promote the color mixture of the light of the LED chip and the light of the phosphor and reduce the unevenness of the emission color. .
Hereinafter, the present invention will be described in more detail with reference to examples.

An LED light-emitting device 1 that is an embodiment of the present invention is shown in FIGS. FIG. 1 is a perspective view of the LED light emitting device 1. FIG. 2 is a cross-sectional view of the LED light-emitting device 1 (a line AA in FIG. 1). The LED light emitting device 1 is a surface mount type (SMD type) LED lamp, and is used as a light source for illumination, for example.
The LED light emitting device 1 is roughly composed of an LED chip 10, a base 20, a lead frame 30, a resin layer 40, and a sealing resin 50.

A schematic cross-sectional view of the LED chip 10 used in the LED light emitting device 1 is shown in FIG. The LED chip 10 has a configuration in which a plurality of group III nitride compound semiconductor layers are stacked on a sapphire substrate, and has an emission peak wavelength in the vicinity of 470 nm. The specifications of each layer of the LED chip 10 are as follows.
Layer: Composition p-type layer 15: p-GaN: Mg
Layer 14 including light emitting layer: n-type layer including InGaN layer 13: n-GaN: Si
Buffer layer 12: AlN
Substrate 11: Sapphire

An n-type layer 13 made of GaN doped with Si as an n-type impurity was formed on the substrate 11 via a buffer layer 12. Here, sapphire is used as the substrate 11, but the substrate 11 is not limited to this, and sapphire, spinel, silicon, silicon carbide, zinc oxide, gallium phosphide, gallium arsenide, magnesium oxide, manganese oxide, group III A nitride compound semiconductor single crystal or the like can be used. Further, the buffer layer is formed by MOCVD using AlN, but the present invention is not limited to this, and GaN, InN, AlGaN, InGaN, AlInGaN, etc. can be used as the material, and molecular beam crystal growth is used as the manufacturing method. A method (MBE method), a halide vapor phase epitaxy method (HVPE method), a sputtering method, an ion plating method, an electron shower method, or the like can be used. When a group III nitride compound semiconductor is used as the substrate, the buffer layer can be omitted.
Further, the substrate and the buffer layer can be removed as necessary after the semiconductor element is formed.
Here, the n-type layer 13 is formed of GaN, but AlGaN, InGaN, or AlInGaN can be used.
The n-type layer 13 is doped with Si as an n-type impurity, but Ge, Se, Te, C, or the like can also be used as an n-type impurity.
The n-type layer 13 can have a two-layer structure including a low electron concentration n ⁻ layer on the layer 14 side including a light emitting layer and a high electron concentration n ⁺ layer on the buffer layer 12 side.
The layer 14 including the light emitting layer may include a quantum well structure (multiple quantum well structure or single quantum well structure), and the light emitting element has a single hetero type, a double hetero type, and a homojunction. It may be of a type.
The layer 14 including the light emitting layer may include a group III nitride compound semiconductor layer having a wide band gap doped with an acceptor such as magnesium on the p-type layer 15 side. This is to effectively prevent the electrons injected into the layer 14 including the light emitting layer from diffusing into the p-type layer 15.
A p-type layer 15 made of GaN doped with Mg as a p-type impurity was formed on the layer 14 including the light-emitting layer. The p-type layer may be AlGaN, InGaN, or InAlGaN, and Zn, Be, Ca, Sr, or Ba may be used as the p-type impurity.
Further, the p-type layer 15 can have a two-layer structure including a low hole concentration p ⁻ layer on the layer 14 side including a light emitting layer and a high hole concentration p ⁺ layer on the electrode side.
In the light emitting device having the above-described configuration, each group III nitride compound semiconductor layer is formed by performing MOCVD under general conditions, a molecular beam crystal growth method (MBE method), a halide vapor phase epitaxy method (HVPE method). ), A sputtering method, an ion plating method, an electron shower method, or the like.

The n-electrode 19 is composed of two layers of Al and V, and after forming the p-type layer 15, the p-type layer 15, the layer 14 including the light emitting layer, and a part of the n-type layer 13 are removed by etching, It is formed on the n-type layer 13 by vapor deposition.
The translucent electrode 17 is a thin film containing gold and is laminated on the p-type layer 15. The p-electrode 18 is also made of a material containing gold, and is formed on the translucent electrode 17 by vapor deposition.
After forming each semiconductor layer and each electrode by the above process, a separation process of each chip is performed.

  A reflective layer can also be provided between the layer 14 including the light emitting layer and the substrate 11 or on the surface of the substrate 11 where the semiconductor layer is not formed. By providing the reflective layer, the light generated in the layer 14 including the light emitting layer and directed toward the substrate can be efficiently reflected in the light extraction direction, and as a result, the light emission efficiency can be improved. The reflective layer can be formed of one or more selected from titanium nitride, zirconium nitride, and tantalum nitride. In addition, a single metal such as Al, In, Cu, Ag, Pt, Ir, Pd, Rh, W, Mo, Ti, Ni, or an alloy made of two or more metals arbitrarily selected from these metals is used. A reflective layer can also be formed.

  The substrate 20 is made of a white resin (polyphthalamide), and its outer shape is substantially cup-shaped. A recess 21 is formed in the upper portion of the base body 20. The inner peripheral surface 22 of the recess 21 surrounds the LED chip 10. The inner peripheral surface 22 is formed to have a desired angle with respect to the optical axis of the LED chip 10. On the other hand, a lead frame 30 is in-molded at the lower part of the base body 20. Thus, the LED light emitting device 1 includes a package structure in which the lead frame 30 is in-molded with a white resin. The lead frame 30 is made of a copper (Cu) alloy.

  The inner peripheral surface 22 of the upper part of the base is covered with a resin layer 40. The resin layer 40 is a silicone resin containing about 30% (w / w) of titanium oxide as a light reflective filler, and has high reflectivity. The thickness of the resin layer 40 gradually increases downward, and the thickness of the thickest portion is about 300 μm. In this embodiment, the surface of the resin layer 40 is inclined at a desired angle with respect to the optical axis of the LED chip 10 by gradually changing the thickness in this way.

A space defined by the surface of the resin layer 40 and the bottom wall of the base recess 21 is filled with a sealing resin 50. In this embodiment, a silicone resin is used as the material of the sealing resin 50. A lens effect may be imparted to the sealing resin 50. For example, the surface shape of the sealing resin 50 can be a concave lens type or a convex lens type, and a desired lens effect can be obtained.
On the other hand, a diffusing agent may be dispersed in the sealing resin 50. By using the diffusing agent, light diffusion and color mixing can be promoted in the sealing resin 50, and uneven light emission can be reduced. As the diffusing agent, titanium oxide, titanium nitride, tantalum nitride, aluminum oxide, silicon oxide, barium titanate, or the like is used.

  Next, a method for manufacturing the LED light emitting device 1 will be described. First, the LED chip 10 is prepared by the above procedure. On the other hand, a copper alloy metal plate that has been die-cut according to the shape of the lead frame 30 is prepared, and a white resin is injection-molded into the lead frame portion. Next, by cutting the metal plate at a desired position, the package in which the lead frame 30 is in-molded with a white resin is separated, and finally the end of the lead frame 30 is shaped. In the package thus manufactured, after the resin layer 40 is formed as described above (see FIG. 7), the LED chip 10 is mounted on the lead frame 30 in accordance with the usual method, wire bonding, and the sealing resin 50 is filled. And so on.

Then, the light emission aspect of the LED light-emitting device 1 is demonstrated. First, blue light is emitted from the LED chip 10 by receiving power. Most of the light emitted upward passes through the sealing resin 50 and is extracted outside through the upper surface of the sealing resin. On the other hand, the light emitted in the lateral direction travels in the sealing resin 50 and reaches the resin layer 40. And it is reflected by the filler (titanium oxide) in the resin layer 40. Thus, most of the light emitted from the LED chip 10 in the lateral direction is reflected by the resin layer 40. That is, the resin layer 40 functions as a main reflecting member. As a result, the amount of light reaching the substrate inner peripheral surface 22 among the light emitted from the LED chip 10 in the lateral direction is small, and light deterioration of the substrate inner peripheral surface 22 is prevented. Thus, by using the resin layer 40 formed on the substrate inner peripheral surface 22 instead of the substrate inner peripheral surface 22 as a reflecting member, a high light extraction efficiency can be obtained without substantial deterioration of the substrate inner peripheral surface 22 over time. Can be achieved. Since the surface of the resin layer 40 is an inclined surface, most of the reflected light from the resin layer 40 can travel in the light emission direction (upward in the drawing) of the LED light-emitting device 1. High light extraction efficiency can be obtained.
On the other hand, since the resin layer 40 and the sealing resin 50 are formed of a silicone resin that exhibits high resistance to light on the short wavelength side, their deterioration and discoloration with time are small. Therefore, a high-quality light-emitting device with little change in luminous intensity and emission color with use is obtained. Here, since the light concentrates on the resin layer 40 due to the reflection action, preventing the light deterioration is particularly effective for preventing the light intensity and the emission color of the LED light emitting device 1 from changing with time.
Furthermore, since the resin layer 40 has good adhesiveness to the resin substrate 20, there is little possibility that the resin layer 40 will be peeled off during or after the forming process, and the effects of improving the manufacturing yield and reliability can be obtained. It is done.

  As described above, the LED light-emitting device that emits blue light by using the LED chip 10 has been described. However, a light-emitting device having a desired light emission color can be configured by appropriately selecting the LED chip to be used. Examples of LED chips that can be used include LED chips that emit light in the ultraviolet region (for example, light having a main emission peak wavelength in the vicinity of 380 nm), LED chips that emit green light, and the like.

Another embodiment of the present invention is shown in FIG. FIG. 3 is a cross-sectional view of the LED light emitting device 2. In addition, the same code | symbol is attached | subjected to the member same as the said Example, and the description is abbreviate | omitted.
The LED light emitting device 2 is a white light emitting SMD (surface mount) type LED lamp, and can be used as a light source for illumination, a backlight light source such as a liquid crystal display device, and the like.
The LED light emitting device 2 includes a phosphor resin layer 60 that seals the LED chip 10. The phosphor resin layer 60 is made of a silicone resin containing 20% (w / w) of phosphor: Y ₃ Al ₅ O ₁₂ : Ce (YAG) 61. Such a phosphor resin layer 60 can be formed by potting a resin material containing a phosphor from the top of the LED chip 10 after being mounted on the LED chip 10 or by applying it to the surface of the LED chip 10. .
In the LED light emitting device 2 having the above configuration, part of the light emitted from the LED chip 10 excites the phosphor 61 in the process of passing through the phosphor resin layer 60, thereby generating yellowish fluorescence. As a result, the LED light-emitting device 2 emits white light that is a mixed color of blue light and yellow light. On the other hand, as a result of the filler in the resin layer 40 exhibiting a light diffusing action in addition to a reflecting action, the color mixture of blue light and yellow light is promoted, and white light with less color unevenness and color separation is obtained. In addition, the same operational effects as the LED light emitting device 1 of the above embodiment, that is, achievement of high light extraction efficiency, prevention of change in luminous intensity and emission color over time, improvement of manufacturing yield, and improvement of reliability are also exhibited. The

  Instead of providing the phosphor resin layer 60 separately, the phosphor 61 may be contained in the sealing resin 50 to obtain a fluorescence action. In this embodiment, part of the light emitted from the LED chip 10 is subjected to wavelength conversion action by the phosphor when passing through the sealing resin 50. The resulting yellow light and the blue light that has not been used for excitation of the phosphor are mixed to emit white light to the outside.

  On the other hand, the phosphor resin layer 60 may be formed so as to coat the surface of the LED chip 10. For example, the surface of the LED chip 10 is coated with the phosphor resin by coating the surface of the LED chip 10 by dipping the resin material in which the phosphor 61 is dispersed and then mounting the LED chip 10. An LED light-emitting device can be manufactured. In addition to the above dipping, the same coating treatment can be performed by sputtering, coating, painting, or the like.

Another embodiment of the present invention is shown in FIG. FIG. 4 is a cross-sectional view of the LED light emitting device 3. In addition, the same code | symbol is attached | subjected to the member same as the said Example, and the description is abbreviate | omitted.
The LED light emitting device 3 shown in FIG. 4 is a white light emitting SMD (surface mount) type LED lamp, and can be used as a backlight light source such as an illumination light source or a liquid crystal display device.
The LED light emitting device 3 includes an LED chip 70 that emits light in the ultraviolet region. The LED chip 70 has a configuration in which a plurality of group III nitride compound semiconductor layers are stacked on a sapphire substrate, and has an emission peak wavelength in the vicinity of 380 nm.

  In the LED light emitting device 3, a package is configured using the substrate 71 and the exterior resin 72. Here, the substrate 71 and the exterior resin 72 correspond to the base in the above description. The LED chip 70 is mounted on the conductor pattern 73 of the substrate 71, and wire bonding is performed. The exterior resin 72 is a molded product of polyphthalamide. By bonding the exterior resin 72 and the substrate 20, a base having a cup-shaped recess is obtained. On the inner peripheral surface 74 of the exterior resin 72, a resin layer 45 containing a light reflective filler is formed. In this embodiment, the thickness of the resin layer 45 is uniform.

On the other hand, a phosphor resin layer 75 is provided to seal the LED chip 70. The phosphor resin layer 75 is a silicone resin in which a red phosphor (first phosphor 76), a green phosphor (second phosphor 77), and a blue phosphor (third phosphor 78) are dispersed. . The amount of each phosphor used is determined in consideration of the conversion efficiency and emission color of each phosphor.
The sealing resin 50 may also contain a phosphor. In this case, not all three types of phosphors may be contained in the sealing resin 50, but only some of the phosphors (for example, only the first phosphor 76 and the second phosphor 77) may be contained. .

  In the LED light emitting device 3 configured as described above, when the ultraviolet light emitted from the LED chip 70 passes through the phosphor resin layer 75, the first phosphor 76, the second phosphor 77, and the third phosphor 78. Is excited to emit light. The resulting fluorescence mixes and white light as a whole is emitted externally. In addition, the light radiate | emitted from LED chip 70 in the horizontal direction is efficiently utilized for excitation of fluorescent substance (76-78) by being reflected by the resin layer 45. FIG.

  In this embodiment, each phosphor is uniformly dispersed in the phosphor resin layer 75. However, it is possible to provide a gradient in the concentration distribution of the phosphor in the phosphor resin layer 75. For example, silicone resins having different phosphor addition concentrations are sequentially stacked on the LED chip 70. On the other hand, as shown in FIG. 5, a plurality of phosphor resin layers having different phosphors may be formed. In this example, two phosphor resin layers 80 and 81 are formed so as to cover the LED chip 70. The phosphor resin layer 80 on the side close to the LED chip 70 contains the first phosphor 76. The other phosphor resin layer 81 contains a second phosphor 77 and a third phosphor 78. The base materials of the phosphor resin layers 80 and 81 are both silicone resins. Note that these two resin layers also serve as a sealing resin. In the LED light emitting device 4 of this example, a red phosphor (first phosphor 76) having a relatively low light conversion efficiency is disposed in the vicinity of the LED chip 70. This increases the amount of light of the LED chip 70 that irradiates the red phosphor, and balances the amount of light from other phosphors. Thus, by devising the arrangement mode of the phosphors, the amount of light from each phosphor can be made uniform, and white light with a good color component balance and excellent color rendering can be obtained.

  In the LED light-emitting devices 3 and 4 of the present embodiment, the same effects as the LED light-emitting device 1 of the above-described embodiment, that is, achievement of high light extraction efficiency, prevention of changes in light intensity and luminescent color with time, and production yield. The effect of improving the reliability and reliability is achieved.

  The LED light-emitting device of the present invention can be used as a light source for various devices. For example, the present invention can be applied to a light source of an illumination device for a vehicle interior or a living room, a backlight light source such as a liquid crystal display device, and the like.

The present invention is not limited to the description of the embodiments and examples of the invention described above. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims.
The contents of papers, published patent gazettes, patent gazettes, and the like specified in this specification are incorporated by reference in their entirety.

It is a perspective view of the LED light-emitting device 1 which is an Example of this invention. It is sectional drawing of the LED light-emitting device 1 which is an Example of this invention. It is sectional drawing of the LED light-emitting device 2 which is another Example. It is sectional drawing of the LED light-emitting device 3 which is another Example. It is sectional drawing of the LED light-emitting device 4 which is another Example. It is a figure which shows the structure of the LED chip 10 used for the LED light-emitting device of an Example. It is a figure which shows the formation method of the resin layer with which the LED light-emitting device of this invention is equipped.

Explanation of symbols

1, 2, 3, 4 LED light emitting device 10 Blue light emitting LED chip 20 Base 21 Base recess 22 Base inner peripheral surface 30 Lead frame 40 Light reflecting filler-containing resin layer 50 Sealing resin 60, 75, 80, 81 Phosphor Resin layer 61 Yellow phosphor 70 UV light emitting LED chip 71 Substrate 72 Exterior resin 73 Conductive pattern 76 Red phosphor 77 Green phosphor 78 Blue phosphor

Claims (6)

An LED chip;
A substrate made of a white resin, the substrate including a portion surrounding the LED chip;
A resin layer containing a light reflective filler, the resin layer covering the inner peripheral surface of the portion of the substrate;
A sealing member filled in a space surrounded by the resin layer so as to cover the LED chip;
An LED light emitting device comprising:   The LED light-emitting device according to claim 1, wherein a base material of the resin layer is silicone.   The LED light-emitting device according to claim 1, wherein the sealing member is made of silicone.   The LED light-emitting device according to claim 1, wherein the resin layer is thicker in a region closer to the LED chip, whereby the surface of the resin layer becomes a surface inclined with respect to the optical axis of the LED chip. . The LED chip is a blue light emitting LED chip;
The sealing member contains a phosphor that receives blue light and emits yellow light.
The LED light-emitting device in any one of Claims 1-4. The LED chip is an ultraviolet light emitting LED chip;
The sealing member receives a phosphor that emits red light upon receiving ultraviolet light, a phosphor that emits green light upon receiving ultraviolet light, and a blue light upon receiving ultraviolet light. A phosphor that emits,
The LED light-emitting device in any one of Claims 1-4.

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