JP7057493B2 - Light emitting device and its manufacturing method - Google Patents

Description

The present invention relates to a light emitting device.

Conventionally, semiconductor light emitting elements such as light emitting diodes have been used for the backlight of a liquid crystal display. For example, in Patent Document 1, as a prior art thereof, in a lighting device provided with a plurality of light emitting diodes, illumination is performed by forming a light shielding portion corresponding to each light emitting diode on a light emitting panel provided separately from the light emitting diode. A lighting device having improved brightness unevenness as a whole device is disclosed. Further, Patent Document 1 discloses that a light shielding film is formed on each light emitting diode because the manufacturing cost of the conventional lighting device is high.

Japanese Unexamined Patent Publication No. 2001-257381

However, conventional light emitting devices such as light emitting diodes that suppress front brightness disclosed in Patent Document 1 cannot sufficiently reduce brightness unevenness when used as a light source such as a thin lighting device. rice field.

Therefore, an object of the present invention is to provide a light emitting device capable of reducing luminance unevenness when used as a light source such as a thin lighting device.

In order to achieve the above object, the light emitting device of one embodiment according to the present invention has a light emitting element that emits first light, a light guide member that covers the light emitting element, and an upper surface and a lower surface. A plate-shaped translucent member provided so that the lower surface faces the upper surface of the light guide member, and at least a part of the first light provided on the upper surface or the lower surface of the translucent member. It has a reflective film that reflects light, and the base material of the translucent member is an inorganic material.

Further, the method for manufacturing the light emitting device according to the present invention is as follows.
The process of preparing a translucent substrate made of an inorganic material,
A step of forming a reflective film layer on one surface of the prepared translucent substrate, and
A step of cutting the translucent substrate on which the reflective film layer is formed and separating the translucent substrate into a plurality of first complexes including a plate-shaped translucent member and a reflective film, respectively.
The process of preparing an assembly board with multiple unit areas, each containing positive and negative wiring, and
The process of mounting the light emitting element in each unit area of the prepared collective substrate, and
A step of forming a light guide member layer that fills the space between adjacent light emitting elements and collectively covers a plurality of light emitting elements on the collective substrate on which the light emitting element is mounted.
A second light guide member layer is cured, and the cured light guide member layer is cut between adjacent light emitting elements to include a substrate, a light emitting element, and a light guide member covering the light emitting element on the substrate, respectively. The process of separating into a complex and
The first complex and the second complex are joined so that the surface of the reflective film or the translucent substrate opposite to the surface on which the reflective film is formed faces the light guide member. And the process to do
including.

According to the light emitting device of one embodiment configured as described above, it is possible to provide a light emitting device capable of reducing luminance unevenness when used as a light source such as a thin lighting device.
Further, according to the method for manufacturing a light emitting device of one embodiment configured as described above, for example, a light emitting device capable of reducing luminance unevenness when used as a light source such as a thin lighting device is manufactured. be able to.

It is sectional drawing of the light emitting device of embodiment which concerns on this invention. It is sectional drawing of the translucent substrate prepared in the manufacturing method of the light emitting device of embodiment. It is sectional drawing when the reflective film layer is formed on one surface of the prepared translucent substrate in the manufacturing method of the light emitting device of embodiment. It is sectional drawing when the translucent substrate which the reflective film layer was formed on one surface was cut and formed into the 1st complex in the manufacturing method of the light emitting apparatus of embodiment. It is sectional drawing of the assembly board prepared in the manufacturing method of the light emitting device of embodiment. It is sectional drawing when the light emitting element is mounted on each unit area of the assembly board in the manufacturing method of the light emitting device of embodiment. It is sectional drawing when forming the light guide member layer which fills the space between adjacent light emitting elements 2 and collectively covers a plurality of light emitting elements 2 in the manufacturing method of the light emitting device of embodiment. FIG. 5 is a cross-sectional view when the cured light guide member layer is cut together with a substrate between adjacent light emitting elements 2 and separated into a second complex in the method for manufacturing a light emitting device of the embodiment. FIG. 5 is a cross-sectional view when the first complex and the second complex 52 are joined so that the reflective film and the light guide member face each other in the method of manufacturing the light emitting device of the embodiment. It is a graph which shows the transmittance with respect to the wavelength of the reflective film used in an Example. It is a graph which shows the light distribution characteristic of the light emitting device of an Example.

Hereinafter, the light emitting device according to the embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a light emitting device according to an embodiment of the present invention.
The light emitting device of the embodiment includes a light emitting element 2 provided on the substrate 10, a light guide member 3 covering the light emitting element 2 on the substrate 10, a reflective film 1 provided on the light guide member 3, and a reflective film. 1 Includes a translucent member 4 provided on top of 1. Here, a configuration in which the reflective film 1 is provided between the light guide member 3 and the translucent member 4 will be described with reference to FIG. 1, but in the present embodiment, the light guide member 3 will be described. A translucent member 4 may be provided on the translucent member 4, and a reflective film 1 may be provided on the translucent member 4.

The light emitting element 2 is provided on the substrate 10 via the conductive bonding member 7, and a voltage is applied via the wiring formed on the substrate 10 to emit light. Hereinafter, the light emitted by the light emitting element 2 is referred to as the first light.

The light guide member 3 is provided on the substrate 10 so as to cover the upper surface and the side surface of the light emitting element 2.
The reflective film 1 is provided on the light guide member 3 and reflects the first light emitted by the light emitting element 2. The reflective film 1 can be composed of, for example, a dielectric multilayer film in which a first dielectric layer 1a and a second dielectric layer 1b having different refractive indexes are alternately laminated. The dielectric multilayer film includes the emission spectrum (intensity distribution with respect to the center wavelength and wavelength) of the first light emitted by the light emitting element 2, the first refractive index of the first dielectric layer 1a, and the second of the second dielectric layer 1b. By setting the film thickness of the first dielectric layer 1a and the film thickness of the second dielectric layer 1b based on the refractive index, the light emitting element 2 can be configured to reflect the first light emitted. ..

The translucent member 4 is provided, for example, in contact with the reflective film 1. The translucent member 4 is, for example, a plate-shaped member made of an inorganic material such as transparent glass having a flat surface in contact with the reflective film 1.
Here, in the present specification, for example, when it is simply "provided on the A member" such as "provided on the light emitting surface of the light emitting element 2", it may be provided in contact with the A member. , The case where the member A is provided on the member A via another layer is included. In the light emitting device of the embodiment, the reflective film 1 is provided on the upper surface of the light guide member 3 via, for example, a translucent adhesive layer.
Further, the light emitting device of the embodiment may include a semiconductor element such as a protective element for preventing the light emitting element 2 from being destroyed by applying an excessive voltage.

In the light emitting device of the embodiment configured as described above, since the reflective film 1 that reflects the first light emitted by the light emitting element 2 is provided on the upper surface of the light guide member 3, the light emitting element 2 emits light. The first light is mainly emitted from the side surface of the light guide member 3, and can realize a wide light distribution characteristic such as a bat wing type light distribution.
Therefore, according to the light emitting device of the embodiment, the light distribution characteristic can be made wide, so that a light emitting device capable of reducing luminance unevenness when used as a light source such as a thin lighting device is provided. Can be provided.

Further, in the light emitting device of the embodiment, when the reflective film 1 is composed of a dielectric multilayer film in which a first dielectric layer 1a and a second dielectric layer 1b having different refractive indexes are alternately laminated, a wide light distribution is provided. In addition to being able to achieve the desired light distribution characteristics.

That is, the reflectance of the dielectric multilayer film has a high reflectance for light incident from a direction orthogonal to the incident surface (incident light having an incident angle of 0 °), and the reflectance increases as the incident angle increases. It has a low incident angle dependence. The incident angle dependence of the reflectance of the dielectric multilayer film is the first refractive index of the first dielectric layer 1a, the second refractive index of the second dielectric layer 1b, the film thickness of the first dielectric layer 1a, and the first. By appropriately setting the film thickness of the 2 dielectric layer 1b, a desired angle of incidence dependence can be realized. Therefore, it is possible to adjust the incident angle dependence in order to realize the desired light distribution characteristics in the light emitting device.

The reflectance (permeability) of the dielectric multilayer film with respect to the wavelength is the material of the first dielectric layer 1a and its first refractive index, the material of the second dielectric layer 1b and its second refractive index, and the first dielectric. It can be adjusted by appropriately setting the film thickness of the body layer 1a and the film thickness of the second dielectric layer 1b. Therefore, by adjusting the reflectance (transmittance) with respect to the wavelength of the dielectric multilayer film in addition to or instead of the incident angle dependence, it is possible to realize desired light distribution characteristics in the light emitting device. .. As described above, according to the light emitting device of the embodiment, it is possible to adjust the light distribution characteristics according to the requirements of the applied lighting device, and it is possible to further reduce the luminance unevenness of the lighting device.

Further, the light guide member 3 may include a wavelength conversion member such as a phosphor that is excited by the first light of the light emitting element 2 and emits light having a wavelength longer than that of the first light (second light). good. When the light guide member 3 includes a wavelength conversion member, the light emission color of the light emitting device becomes the light emission color of the second light when the light emitted from the light guide member 3 is substantially only the second light. If the light emitted from the light guide member 3 is the first light and the second light, the emission color of the light is a mixture of the first light and the second light. When the light guide member 3 includes a wavelength conversion member as described above, the reflection characteristics of the reflective film 1 are taken into consideration in consideration of the light emission spectrum of the light emitted from the light guide member 3 and the light distribution characteristics required for the light emitting device. When the dielectric multilayer film is used as the reflecting film, the incident angle dependence of the dielectric multilayer film and the reflectance (transmissivity) with respect to the wavelength of the dielectric multilayer film may be appropriately adjusted.

Hereinafter, each component of the light emitting device of the embodiment will be described in detail.
(substrate)
It is preferable that the substrate 10 has an insulating property and does not easily transmit light. Examples of the material of the substrate 10 include ceramics such as alumina and aluminum nitride, phenol resins, epoxy resins, polyimide resins, BT resins, and resins such as polyphthalamide. Of these, ceramics are preferable because they have a high heat dissipation effect. When a resin is used, an inorganic filler such as glass fiber, silicon oxide, titanium oxide, or alumina may be mixed with the resin, if necessary. As a result, it is possible to improve the mechanical strength, reduce the coefficient of thermal expansion, and improve the light reflectance. However, the light emitting device of the embodiment does not have to have the substrate 10. In this case, it is preferable that the electrode of the light emitting element or the conductive member electrically connected to the electrode of the light emitting element is exposed from the lower surface of the light emitting device to be an external electrode of the light emitting device.

(Light emitting element)
As the light emitting element 2, for example, a light emitting diode (LED) chip or a laser diode (LD) chip can be used, and it is particularly preferable to use an LED chip. By using the light emitting element 2 as a light emitting diode chip, the light from the light emitting element 2 can easily spread. When the light guide member 3 includes a wavelength conversion member, if the light from the light emitting element 2 easily spreads, the phosphor can be efficiently excited. As the light emitting element 2, for example, a light emitting diode chip containing a nitride semiconductor can be used. When the light guide member 3 includes a wavelength conversion member, for example, a blue light emitting diode chip containing a nitride semiconductor is used as the light emitting element 2. Here, the light emitting diode chip that emits blue light refers to a chip having an emission peak wavelength in the range of 435 nm to 480 nm.

The nitride semiconductor referred to here is a semiconductor represented by the general formula: In _X Al _Y Ga _1-XY N (0 ≦ X, 0 ≦ Y, X + Y ≦ 1), and the composition of the semiconductor layer and its mixed crystals. Various emission wavelengths can be selected depending on the degree. The light emitting device 2 using a nitride semiconductor includes, for example, a growth substrate 2b such as sapphire capable of growing a nitride semiconductor and a semiconductor laminate 2a provided on the growth substrate 2b.

In the light emitting device 2, the semiconductor laminate 2a is provided with a p electrode and an n electrode. As shown in FIG. 1, in the light emitting element 2, it is preferable that the p electrode and the n electrode are formed on the same side surface of the light emitting element 2 and are flip-chip mounted on the substrate 10. As a result, the upper surface (light emitting surface) of the light emitting element 2 becomes a flat surface, and the light guide member 3 can be arranged close to the light emitting element 2. In FIG. 1, the light emitting element 2 has a growth substrate 2b, but the growth substrate 2b may be removed at the time of mounting or after mounting.

(Light guide member)
The light guide member 3 is preferably formed of a material having good translucency, for example, a thermosetting resin, a thermoplastic resin, or the like. Examples of the thermosetting resin include silicone resin, silicone modified resin, silicone hybrid resin, epoxy resin, epoxy modified resin, urea resin, diallyl phthalate resin, phenol resin, polyimide resin, unsaturated polyester resin, and these resins. Examples include hybrid resins containing more than one type. In particular, a silicone resin or a modified resin or a hybrid resin thereof is preferable because it has excellent heat resistance and light resistance. The refractive index of the light guide member 3 is preferably about 1.4 to 1.5. The light guide member 3 may have a transmittance of 50% or more, preferably 70% or more, and more preferably 85% or more.
The light guide member 3 may contain a diffusing agent, if necessary. Further, the light guide member 3 is formed to have a thickness of, for example, 30 to 150 μm, preferably 50 to 120 μm.

(When the light guide member contains a phosphor as a wavelength conversion member)
The light guide member 3 containing a phosphor absorbs a part or all of the first light from the light emitting element 2 to generate light having a different wavelength.
In the present embodiment, the light guide member 3 containing a phosphor is formed by using, for example, a translucent resin containing phosphor particles. The light guide member 3 may be composed of one or two or more layers. The light guide member 3 may contain a diffusing agent, if necessary.

The average particle size of the phosphor particles contained in the resin is preferably 2 μm to 40 μm, more preferably 10 μm to 40 μm, and even more preferably 15 μm to 40 μm.
When the total volume of the phosphor particles contained in the resin is the same, the particle size increases as the particle size decreases, and the light emitted by the phosphor particles is easily scattered by other phosphor particles, resulting in light extraction efficiency. Decreases. On the other hand, when the particle size is large, the scattering is small and the light extraction efficiency is high, but the surface area of the particles is small, the amount of light emitted by the phosphor is small, and the amount of light that is not wavelength-converted increases. In the present embodiment, the light that reaches the reflective film 1 without being wavelength-converted is returned to the light guide member side again by the reflective film 1, so that scattering on the particle surface is caused by increasing the particle size of the phosphor particles. It is possible to efficiently perform wavelength conversion of the light of the light emitting element while suppressing it. Therefore, in the light emitting device of the embodiment, by increasing the particle size of the phosphor particles, the light of the light emitting element can be efficiently wavelength-converted, and the light extraction efficiency can be improved.
The average particle size of the phosphor particles referred to in the present specification refers to the average particle size of the secondary particles formed by aggregating the primary particles. The average particle size (median diameter) of the secondary particles can be measured by, for example, a laser diffraction type particle size distribution measuring device (manufactured by MALVERN, product name: MASTER SIZER 3000).

As the phosphor particles, materials known in the art can be used. For example, a yttrium aluminum garnet (YAG) fluorophore activated with cerium, a lutetium aluminum garnet (LAG) fluorophore activated with cerium, europium and / or chromium-activated nitrogen-containing calcium aluminosilicate. (CaO-Al ₂ O ₃ -SiO ₂ ) -based fluorescent material, europium-activated silicate ((Sr, Ba) ₂ SiO ₄ ) -based fluorescent material, β-sialon fluorescent material, KSF-based fluorescent material (K ₂ SiF ₆ :): Mn), CASN, S-CASN, SAE-based phosphor (Sr ₄ Al ₁₄ O ₂₅ : Eu) and the like can be mentioned. This makes it possible to obtain a light emitting device that emits a mixed color light (for example, a white system) of primary light and secondary light having a visible wavelength.

Further, the phosphor particles may be, for example, a so-called nanocrystal or a light emitting substance called a quantum dot. These materials include semiconductor materials such as II-VI group, III-V group, IV-VI group semiconductors, specifically ZnS, CdS, CdSe, _InAgS2 , InCuS2, and core-shell type CdS _x Se ₁ . Examples thereof include nano-sized highly dispersed particles such as _−x / ZnS and GaP. It may be InP, InAs, InAsP, InGaP, ZnTe, ZnSeTe, ZnSnP, ZnSnP ₂ .

Further, the emission color of the light emitting device is preferably white. Further, an emission color other than white may be used, and an arbitrary color such as red, blue, or green can be used by selecting the emission wavelength of the light emitting element and the type of phosphor particles.

(Reflective film)
As the reflective film, it is preferable to use a dielectric multilayer film whose reflectance with respect to the incident angle can be adjusted. Further, the dielectric multilayer film can be made highly selective. Here, high selectivity means that the reflectance in the reflection wavelength band is high, the transmittance in the transmission wavelength band is high, and the change in reflectance or transmittance is steep between the reflection wavelength band and the transmission wavelength band. To say.

Dielectric multilayer film The dielectric multilayer film is a reflective film in which two first dielectric layers 1a and a second dielectric layer 1b having different refractive indexes are alternately and periodically formed with a film thickness of λ / 4. be. Here, λ is the peak wavelength in the wavelength region to be reflected, and is the in-medium wavelength in each dielectric material. Theoretically, this dielectric multilayer film has a higher reflectance as the difference in refractive index between the two first dielectric layers 1a and the second dielectric layer 1b is larger and the number of cycles formed alternately is larger. It is known to be obtained. However, if the difference in refractive index between the two first dielectric layers 1a and the second dielectric layer 1b is too large or the number of cycles is too large, the reflectance may decrease sharply on both sides of the reflection peak wavelength λ (wavelength). The dependence becomes steep), and the wavelength dependence of the reflectance becomes large, so that it becomes difficult to stably obtain the desired reflectance in a desired wavelength range. Therefore, in the dielectric multilayer film, the refractive index and the difference in refractive index of the first dielectric layer 1a made of a dielectric material having a high refractive index and the second dielectric layer 1b made of a dielectric material having a low refractive index are alternately arranged. The number of cycles to be formed is appropriately set so that a desired refractive index can be stably obtained in a desired wavelength range.

Specifically, the refractive index (first refractive index) of the first dielectric layer 1a having a high refractive index is set in the range of, for example, 1.5 to 3.0, and preferably 2.0 to 2. It is set in the range of 6. The refractive index (second refractive index) of the second dielectric layer 1b having a low refractive index is set, for example, in the range of 1.0 to 1.8, preferably in the range of 1.2 to 1.6. Is set to. Further, the number of cycles for alternately forming the first dielectric layer 1a and the second dielectric layer 1b is set, for example, in the range of 1 to 20, preferably in the range of 1 to 5.

The dielectric material constituting the first dielectric layer 1a can be selected from, for example, TiO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ and Zr ₂ O ₅ . The dielectric material constituting the second dielectric layer 1b can be made of, for example, a material selected from SiO ₂ , Al ₂ O ₃ and SiO N.

(Translucent member)
A reflective film 1 is provided on one surface of the translucent member 4. As the translucent member 4, a plate-shaped translucent material made of an inorganic material such as glass is used. As the glass material, for example, borosilicate glass or quartz glass can be used.
The thickness of the translucent member 4 may be such that the mechanical strength in the manufacturing process does not decrease and sufficient mechanical strength can be imparted to the light guide member 3. Further, the translucent member 4 may contain a diffusing agent. In a light emitting device in which a translucent member 4 is provided on the light guide member 3 and a reflective film 1 is provided on the translucent member 4, when the translucent member 4 contains a diffusing agent, reflection is performed. The light incident on the film 1 can be averaged. As the diffusing agent, titanium oxide, barium titanate, aluminum oxide, silicon oxide and the like can be used. Further, when the reflective film 1 is provided between the light guide member 3 and the translucent member 4, the upper surface of the translucent member 4 serving as a light emitting surface (the reflective film 1 and the light guide member 3 are provided). The surface opposite to the surface) is not limited to a flat surface, and may have fine irregularities. If the light emitting surface has irregularities, the light emitted from the light emitting surface is scattered and it is possible to suppress uneven brightness and color unevenness.

(Conductive joining member)
A bump can be used as the conductive bonding member 7, and Au or an alloy thereof can be used as the bump material, and eutectic solder (Au-Sn), Pb-Sn, lead-free solder, or the like can be used as another conductive bonding member. Can be used. Although FIG. 1 shows an example in which a bump is used for the conductive bonding member 7, the conductive bonding member 7 is not limited to the bump, and may be, for example, a conductive paste or plating.

Hereinafter, a method for manufacturing a light emitting device according to an embodiment will be described.
The method for manufacturing the light emitting device according to the embodiment is as follows.
(1) A first complex including a plate-shaped translucent member 4 and a reflective film 1 formed on one surface of the translucent member 4, which are individually separated corresponding to one light emitting device. The first complex manufacturing process to be manufactured and
(2) A second complex manufacturing step of manufacturing a second complex including a substrate 10 and a light emitting element 2 mounted on the substrate 10, each of which is individually separated corresponding to one light emitting device. When,
(3) A joining step of joining the first complex and the second complex,
including.
Hereinafter, the first complex manufacturing step, the second complex manufacturing step, and the joining step will be described with reference to the drawings.

1. 1. First complex preparation step 1-1. Preparation of Translucent Substrate Here, first, as shown in FIG. 2A, the translucent substrate 104 is prepared.
Here, the translucent substrate 104 is made of an inorganic material. Further, it is preferable that one surface of the translucent substrate 104 is polished to a surface roughness Ra of 20 nm or less, preferably 10 nm or less, and more preferably 3 nm or less. Further, the other surface of the translucent substrate 104 may be formed with irregularities for scattering light.

1-2. Reflective film formation Next, as shown in FIG. 2B, the reflective film layer 101 is formed on one surface of the translucent substrate 104.
For example, the first dielectric layer and the second dielectric layer having different refractive indexes are alternately laminated to form a reflective film layer 101 made of a dielectric multilayer film.

The reflective film layer 101 made of this dielectric multilayer film is formed by alternately forming a first dielectric layer and a second dielectric layer by an atomic layer deposition method (ALD), sputtering, a vapor deposition method, or the like. Can be done. Among the above-mentioned forming methods, when the reflective film layer 101 is formed by the atomic layer deposition method (ALD), the first dielectric layer and the first dielectric layer can be formed with uniform film thickness, which is desired. It is possible to accurately form a reflective film having the reflective characteristics of.

Further, when the reflective film is formed on the surface of a smooth translucent substrate having a surface roughness Ra of 20 nm or less, preferably 10 nm or less, more preferably 3 nm or less, for example, a first dielectric having a thin film thickness of 30 nm to 100 nm. The body layer and the second dielectric layer can be formed to be extremely flat and have little variation in film thickness, and desired reflectance characteristics can be realized with high accuracy.

1-3. Individualization Next, as shown in FIG. 2C, individualization is performed into a first complex corresponding to each light emitting device.
Specifically, for example, the translucent substrate 104 on which the reflective film layer 101 is formed is cut perpendicularly to one surface of the translucent substrate 104 by a dicer.
As described above, the first complex 51 including the plate-shaped translucent member 4 and the reflective film 1 formed on one surface thereof is manufactured corresponding to one light emitting device.

2. 2. Second complex preparation step 2-1. Assembly board preparation step Here, first, as shown in FIG. 3A, the assembly substrate 110 is prepared. Here, in the present specification, the collective substrate means a substrate including a plurality of unit regions that become the substrate 10 corresponding to each light emitting device after division, and the plurality of unit regions are, for example, the collective substrate 110. It is arranged in a matrix with a plurality of rows and a plurality of columns. Although not shown in FIGS. 3A, 3B to 3D and 4 below, in the collective substrate 110, a positive wiring conductor and a negative wiring conductor are formed in each unit region.

2-2. Light emitting element mounting step Next, as shown in FIG. 3B, the light emitting element 2 is mounted in each unit region of the collective substrate 110. As shown in FIG. 3B, the light emitting element 2 is flip-chip mounted on the collective substrate 110, for example. Specifically, as the light emitting element, the p electrode and the n electrode (not shown) are formed on the same surface side, that is, on the surface of the semiconductor laminate 2a on the opposite side of the growth substrate 2b in the light emitting element 2. Prepare 2. Then, a conductive bonding member is arranged on the positive wiring conductor and the negative wiring conductor in each unit region of the collective substrate 110, and the p electrode and the n electrode of the light emitting element 2 are the positive wiring conductor and the negative wiring conductor, respectively. The conductive joining member 7, the light emitting element 2, and the conductive pattern on the substrate are joined so as to face each other. Although the case where the conductive bonding member is provided on the collective substrate 110 at the time of mounting has been described as an example, the conductive bonding member may be provided on the light emitting element 2 side for bonding.

2-3. Light guide member forming step Here, as shown in FIG. 3C, the light guide member layer 103 is formed so as to fill the space between the adjacent light emitting elements 2 and collectively cover the plurality of light emitting elements 2. The light guide member layer 103 can be formed by applying a translucent resin such as an epoxy resin, a silicone resin, a phenol resin, and a polyimide resin, and the resin can be fluorescent if necessary. Incorporate body etc. Then, the applied light guide member is cured.

2-4. Individualization Next, as shown in FIG. 3D, individualization is performed into a second complex 52 corresponding to each light emitting device.
Specifically, for example, the cured light guide member layer 103 is cut together with the collective substrate 110 between the adjacent light emitting elements 2 by a dicer, and the light emitting element 2 is placed on the substrate 10, the light emitting element 2, and the substrate 10, respectively. It is separated into a second complex 52 including a light guide member 3 to cover.

3. 3. Joining Step As shown in FIG. 4, the first complex 51 and the second complex 52 prepared as described above are joined so that the reflective film 1 and the light guide member 3 face each other. Here, for example, a silicone resin having high heat resistance and light resistance is applied as an adhesive on the first complex, and the first complex is integrated with the second complex and then cured to be bonded. When a silicone resin is used as the adhesive, it is preferable to use a dimethyl-based silicone resin. The side surface of the first complex 51 including the translucent member 4 and the side surface of the second complex 52 including the light guide member 3 may be substantially flush with each other or may have a step. When there is a step, the upper surface of the second complex may be formed larger than the lower surface of the first complex 51, or the upper surface of the second complex may be formed smaller than the lower surface of the first complex 51. It may have been.

In the method for manufacturing a light emitting device according to the above-described embodiment, after the individualized first complex and the second complex are produced, the individualized first complex and the second complex are combined. I tried to join.
However, in the method for manufacturing a light emitting device of the embodiment, as shown in the following modification, both or one of the first complex and the second complex is joined before being individualized and divided after joining ( It may be individualized). In the following description, the state before the individualization of the first complex is referred to as a first complex substrate, and the state before the individualization of the second complex is referred to as a second complex substrate. ..

Modification example 1.
In the method for manufacturing the light emitting device of the first modification, the above-mentioned 1. 1-1. In the first complex manufacturing step. Translucent substrate preparation process and 1-2. Through the reflective film forming step, a first complex substrate in which the reflective film layer 101 is formed on one surface of the translucent substrate 104 as shown in FIG. 2B is produced.

Next, as described above, 2. 2-1. In the second complex manufacturing step. Assembly board preparation process and 2-2. Light emitting element mounting process and 2-3. Through the light guide member forming step, a plurality of light emitting elements 2 are mounted on the collective substrate 110 shown in FIG. 3C, and the light emitting members 2 fill the space between the adjacent light emitting elements 2 and collectively cover the plurality of light emitting elements 2. A second composite substrate on which the layer 103 is formed is produced.

Next, after joining the first complex substrate and the second complex substrate, each light emitting device is individualized.
According to the method for manufacturing the light emitting device of the first modification as described above, the first complex substrate and the second complex substrate can be integrated into individual pieces, and the first complex and the second complex can be separated from each other. Since it is possible to join all at once without joining them individually, the manufacturing cost can be reduced.

Modification example 2.
In the method for manufacturing the light emitting device of the second modification, the above-mentioned 1. 1-1. In the first complex manufacturing step. Translucent substrate preparation process and 1-2. Through the reflective film forming step, a first complex substrate in which the reflective film layer 101 is formed on one surface of the translucent substrate 104 as shown in FIG. 2B is produced.

Next, as described above, 2. 2-1. In the second complex manufacturing step. Assembly board preparation process and 2-2. Light emitting element mounting process and 2-3. Light guide member forming process and 2-4. The second complex shown in FIG. 3D is produced through the individualization step.

Then, for example, the second complex is bonded onto the reflective film layer 101 of the first complex substrate at predetermined intervals.
After that, the first complex substrate is cut and individualized for each light emitting device.

Modification example 3.
In the method for manufacturing the light emitting device of the modified example 3, the above-mentioned 1. 1-1. In the first complex manufacturing step. Translucent substrate preparation process and 1-2. Reflective film forming process and 1-3. The first complex shown in FIG. 2C is produced through the individualization step.

Next, as described above, 2. 2-1. In the second complex manufacturing step. Assembly board preparation process and 2-2. Light emitting element mounting process and 2-3. The second complex substrate shown in FIG. 3C is manufactured through the light guide member forming step.

Next, for example, the first complex is aligned and bonded onto the light guide member layer 103 of the second composite substrate so as to face the light emitting element 2 via the light guide member layer 103.
After that, the second complex substrate is cut and individualized for each light emitting device.

As described above, the method for manufacturing the light emitting device of the embodiment can be variously modified.

Hereinafter, examples according to the present invention will be described.
The light emitting devices of Examples 1 to 3 and the light emitting devices of Comparative Examples were configured as follows, and the light distribution characteristics were evaluated respectively.

Example 1.
As the light emitting device of Example 1, a light emitting device including two light emitting elements was manufactured. The substrate, light emitting element, light guide member, reflective film, and translucent member were each configured as follows.
As the substrate, a substrate in which the lead frame was supported by a thermosetting resin was used.
As the light emitting element, two rectangular light emitting diodes having a emission peak wavelength of 455 nm and a side of 650 μm were used.
The light guide member was formed so as to collectively cover the two light emitting elements.
The light guide member includes yttrium aluminum garnet (YAG) fluorescent material, cerium-activated lutetium aluminum garnet (LAG) fluorescent material, and S-CASN fluorescent material ((Sr, Ca)) as fluorescent materials. ) AlSiN ₃ : Eu ²⁺ ) and a SAE-based phosphor (Sr ₄ Al ₁₄ O ₂₅ : Eu) were contained.
Further, the light guide member was formed so as to cover the upper surface and the side surface of the light emitting element.
As the reflective film 1, in FIG. 5, a dielectric multilayer film having a transmittance of about 25% in the visible light region shown by T25 was used.
The dielectric multilayer film has a first dielectric layer made of Nb ₂ O ₅ and a second dielectric layer made of SiO ₂ , and a second dielectric layer and a first dielectric layer on the translucent member 4. The second dielectric layer and the first dielectric layer were alternately laminated in the order of 6.5 cycles (13 layers in total) by a sputtering method.
The thickness of each layer of the dielectric multilayer film was set so as to satisfy the transmittance characteristic shown in T25 of FIG.
As the translucent member, a glass plate made of SiO ₂ and having a thickness of about 1 mm was used.
The light guide member and the reflective film were joined with a silicone resin.

Example 2.
In the light emitting device of Example 1, light emission of Example 1 is used except that a dielectric multilayer film having a transmittance of about 50% in the visible light region shown by T50 in FIG. 5 is used as the reflective film 1. The light emitting device of Example 2 was produced in the same manner as the device.
The dielectric multilayer film of the second embodiment has a first dielectric layer made of Nb ₂ O ₅ and a second dielectric layer made of SiO ₂ on a translucent member, a second dielectric layer and a first dielectric. The layers, the second dielectric layer, and the first dielectric layer were alternately laminated in this order for 6 cycles (12 layers in total) by a sputtering method.
The thickness of each layer of the dielectric multilayer film was set so as to satisfy the transmittance characteristic shown in T50 of FIG.

Example 3.
In the light emitting device of Example 1, light emission of Example 1 is used except that a dielectric multilayer film having a transmittance of about 75% in the visible light region shown by T75 in FIG. 5 is used as the reflective film 1. The light emitting device of Example 3 was produced in the same manner as the device.
The dielectric multilayer film of Example 3 has a first dielectric layer made of Nb ₂ O ₅ and a second dielectric layer made of SiO ₂ on a translucent member, a second dielectric layer, and a first dielectric. The layers, the second dielectric layer, and the first dielectric layer were alternately laminated in the order of 3.5 cycles (7 layers in total) by a sputtering method.
The thickness of each layer of the dielectric multilayer film was set so as to satisfy the transmittance characteristic shown in T75 in FIG.

Comparative Example The light emitting device of Comparative Example was produced in the same manner as the light emitting device of Example 1 except that the light emitting device of Example 1 was configured except for the translucent member and the reflective film.

The light distribution characteristics of the light emitting devices of Examples 1 to 3 and the light emitting devices of Comparative Examples produced as described above were measured. The results are shown in FIG. As shown in FIG. 6, it was confirmed that the light distribution characteristics of the light emitting devices of Examples 1 to 3 provided with the reflective film 1 were wider than those of the light emitting devices of the comparative example not provided with the reflective film 1. Further, as can be seen from the light distribution characteristics of the light emitting devices of Examples 1 to 3, it was confirmed that the light distribution characteristics of the light emitting device can be adjusted by changing the transmittance of the reflective film 1.

1 Reflective film 2 Light emitting element 3 Light guide member 4 Translucent member 7 Conductive joining member 51 First composite 52 Second composite 101 Reflective film layer 103 Light guide member layer 104 Translucent substrate 110 Assembly substrate

Claims (15)

A light emitting element that emits the first light and
The light guide member that covers the light emitting element and
A plate-shaped translucent member having an upper surface and a lower surface on the light emitting surface side and the lower surface facing the upper surface of the light guide member.
A reflective film provided on the lower surface of the translucent member and reflecting at least a part of the first light,
Have,
The base material of the translucent member is an inorganic material.
The reflective film is a dielectric multilayer film, and the dielectric multilayer film is characterized by having an incident angle dependence in which the reflectance decreases as the incident angle increases in the visible light region. Light emitting device. The light emitting device according to claim 1, wherein the base material of the translucent member is glass. The light emitting device according to claim 1 or 2, wherein the reflective film is a dielectric multilayer film. The light guide member contains a phosphor that is excited by the first light and emits a second light having a wavelength longer than that of the first light.
The light emitting device according to any one of claims 1 to 3, wherein the reflective film reflects at least a part of the second light. The light emitting device according to any one of claims 1 to 4, wherein the reflective film has a transmittance of 50% or less when the incident angle is 0 ° with respect to light having a wavelength in the range of 500 nm to 780 nm. The light emitting device according to any one of claims 1 to 4, wherein the reflective film has a transmittance of 25% or less when the incident angle is 0 ° with respect to light having a wavelength in the range of 500 nm to 780 nm. The light emitting device according to any one of claims 1 to 6, wherein the side surface of the translucent member and the side surface of the light guide member are substantially flush with each other. The light emitting device according to any one of claims 1 to 7, wherein the light emitting device has a bat wing type light distribution characteristic. The process of preparing a translucent substrate made of an inorganic material,
A step of forming a reflective film layer on one surface of the prepared translucent substrate, and
A step of cutting the translucent substrate on which the reflective film layer is formed and separating the translucent substrate into a plurality of first complexes including a plate-shaped translucent member and a reflective film, respectively.
The process of preparing an assembly board with multiple unit areas, each containing positive and negative wiring, and
The process of mounting the light emitting element in each unit area of the prepared collective substrate, and
A step of forming a light guide member layer that fills the space between adjacent light emitting elements and collectively covers a plurality of light emitting elements on the collective substrate on which the light emitting element is mounted.
A second light guide member layer is cured, and the cured light guide member layer is cut between adjacent light emitting elements to include a substrate, a light emitting element, and a light guide member covering the light emitting element on the substrate, respectively. The process of separating into a complex and
A step of joining the first complex and the second complex so that the reflective film and the light guide member face each other.
A method for manufacturing a light emitting device including. The process of preparing a translucent substrate made of an inorganic material,
A step of forming a reflective film layer on one surface of the prepared translucent substrate to prepare a first complex substrate, and
The process of preparing an assembly board with multiple unit areas, each containing positive and negative wiring, and
The process of mounting the light emitting element in each unit area of the prepared collective substrate, and
A step of forming a second composite substrate by forming a light guide member layer that fills the space between adjacent light emitting elements on the collective substrate on which the light emitting element is mounted and collectively covers a plurality of light emitting elements.
A step of joining the first complex substrate and the second complex substrate so that the reflective film layer and the light guide member layer face each other.
A step of dividing the second complex substrate together with the first complex substrate so as to include the unit region, respectively.
A method for manufacturing a light emitting device including. The process of preparing a translucent substrate made of an inorganic material,
A step of forming a reflective film layer on one surface of the prepared translucent substrate to prepare a first complex substrate, and
The process of preparing an assembly board with multiple unit areas, each containing positive and negative wiring, and
The process of mounting the light emitting element in each unit area of the prepared collective substrate, and
A step of forming a light guide member layer that fills the space between adjacent light emitting elements and collectively covers a plurality of light emitting elements on the collective substrate on which the light emitting element is mounted.
A second light guide member layer is cured, and the cured light guide member layer is cut between adjacent light emitting elements to include a substrate, a light emitting element, and a light guide member covering the light emitting element on the substrate, respectively. The process of separating into a complex and
A step of joining the second complex onto the first complex substrate so that the reflective film layer and the light guide member face each other.
A step of cutting the first complex substrate for each of the second complexes, and
A method for manufacturing a light emitting device including. The process of preparing a translucent substrate made of an inorganic material,
A step of forming a reflective film layer on one surface of the prepared translucent substrate, and
A step of cutting the translucent substrate on which the reflective film layer is formed and separating the translucent substrate into a plurality of first complexes including a plate-shaped translucent member and a reflective film, respectively.
The process of preparing an assembly board with multiple unit areas, each containing positive and negative wiring, and
The process of mounting the light emitting element in each unit area of the prepared collective substrate, and
A step of forming a second composite substrate by forming a light guide member layer that fills the space between adjacent light emitting elements on the collective substrate on which the light emitting element is mounted and collectively covers a plurality of light emitting elements.
The first complex is aligned on the light guide member of the second complex substrate so as to face the light emitting element, and the reflective film layer and the light guide member layer are joined so as to face each other. Process and
A step of cutting the second complex substrate so as to include the unit region, respectively.
A method for manufacturing a light emitting device including. The method for manufacturing a light emitting device according to any one of claims 9 to 12, wherein the translucent substrate is glass. The light emitting device according to any one of claims 9 to 13, further comprising a step of forming the reflective film layer by alternately laminating a first dielectric layer and a second dielectric layer having different refractive indexes. Production method. Before forming the reflective film layer, a step of polishing one surface of the translucent substrate on the side of the translucent substrate on which the reflective film is formed so that the surface roughness Ra is 20 nm or less. The method for manufacturing a light emitting device according to claim 14, which includes.

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