JP7011303B2 - Manufacturing method of reflective substrate and electrodeposition liquid - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act [Fact 1] Date of issue: June 29, 2017, Publication: Institute of Electrical Engineers of Japan, DEI-17-070 / EFM-17-08, pp. 33-36 , Institute of Electrical Engineers of Japan, "Effects of differences in alumina particle particle size and morphology on the film structure in an alumina-resin composite film produced by the electrophoresis deposition method", Published by: Yusuke Aoki, [Fact 2] Date: August 29, 2017, Publication: 2017 IEICE Electronics Society Conference Proceedings (DVD-ROM), Volume 2, Page 40, Institute of Electrical Engineers of Japan, "Electrical Engineers" Preparation of Alumina-Resin Composite Film by Migration and Deposition Method ”, Published by: Yusuke Aoki, [Fact 3] Publication date: November 22, 2017, Publication: Molecular Cystals and Liquid Crystals, 2017, Vol. 654, Nos. 103-108, "Influence of depositions on the study of aluminum coationg on metallic ealectrophoretic diagnosis with digital reference"

The present invention relates to a reflective substrate, a method for manufacturing the reflective substrate, an electrodeposition liquid, and an LED package.

The aluminum substrate, the plurality of antireflection processing layers provided on the aluminum substrate, the LED elements mounted on the plurality of antireflection processing layers, and the plurality of antireflection processing layers on the aluminum substrate. A printed wiring board bonded to an area other than the provided area, a wire connecting the printed wiring board and the LED element, a dam material arranged around the LED element, and an inner region of the dam material. There is known an LED (light emitting diode) lighting device having a phosphor resin arranged in (Patent Document 1).

JP-A-2015-207743

However, the aluminum substrate has room for improvement in terms of reflectance. In addition, there is room for improvement in the reflectance of the reflective substrate applied to other devices.

Therefore, an object of the present invention is to provide a reflective substrate having a large reflectance.

The reflective substrate according to the present invention is a reflective substrate having a metal substrate and a reflective layer formed on the metal substrate, and the reflective layer contains white ceramic particles and an organopolysiloxane crosslinked body, and is white. The ceramic particles are characterized by having a specific surface area of 6 m ² / g or more and 50 m ² / g or less and a particle size of 0.2 μm or more and 2 μm or less.

The reflective substrate of the present invention has a large reflectance.

FIG. 1 is a diagram showing a specific example of the structure of an organopolysiloxane crosslinked product. FIG. 2 is a diagram for explaining an electrophoretic electrodeposition method using an electrodeposition liquid. FIG. 3 is a diagram for explaining an electrophoretic electrodeposition method using an electrodeposition liquid. FIG. 4 is a plan view of the LED package according to the embodiment. FIG. 5 is a cross-sectional view taken along the line AA'of FIG. FIG. 6 is a cross-sectional view of a modified example of the LED package according to the embodiment. FIG. 7 is a cross-sectional view of the LED package according to another embodiment. FIG. 8 is a diagram showing the change in reflectance with respect to the specific surface area. FIG. 9 is a diagram showing changes in reflectance with respect to particle size.

An embodiment (embodiment) for carrying out the present invention will be described in detail. The present invention is not limited to the contents described in the following embodiments. In addition, the components described below include those that can be easily assumed by those skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Further, various omissions, substitutions or changes of the configuration can be made without departing from the gist of the present invention.

<Reflective substrate>
The reflective substrate according to the embodiment has a metal substrate and a reflective layer formed on the metal substrate.

Examples of the metal substrate include substrates such as aluminum, stainless steel, titanium, and copper. Specific examples of the aluminum substrate include a pure aluminum substrate, an alloy plate containing aluminum as a main component, a substrate obtained by depositing high-purity aluminum on low-purity aluminum, and an aluminum substrate subjected to a plasma electrolytic oxidation method. Be done. The thickness of the metal substrate is not particularly limited, but is, for example, 0.1 mm or more and 3 mm or less.

The reflective layer contains white ceramic particles and an organopolysiloxane crosslinked product.

Examples of the white ceramic particles include particles such as alumina (aluminum oxide), zirconia (zirconium dioxide), and titania (titanium dioxide). Of these, zirconia is preferably used. The white ceramic particles may be used alone or in combination of two or more.

The white ceramic particles have a specific surface area of 6 m ² / g or more and 50 m ² / g or less, preferably 6 m ² / g or more and 13 m ² / g or less. When the specific surface area is in the above range, the reflectance of the reflective layer can be increased. If the specific surface area is smaller than 6 m ² / g, mass production may be difficult due to cost and other factors. Here, the specific surface area is a value obtained by the gas adsorption BET method in accordance with JIS R1626.

The white ceramic particles have a particle diameter of 0.2 μm or more and 2 μm or less. When the particle size is in the above range, a dense reflective layer can be obtained. In addition, the reflectance of the reflective layer can be increased. Here, the particle size is the median value (median diameter, d50) of the particle size distribution obtained by the laser diffraction / scattering method in accordance with JIS R1629.

The organopolysiloxane crosslinked body has a role of a binder for binding the white ceramic particles. FIG. 1 is a diagram showing a specific example of the structure of an organopolysiloxane crosslinked product. As shown in FIG. 1, in this organopolysiloxane crosslinked product, it is considered that the organopolysiloxane 1 is crosslinked via the silica glass 2. The organopolysiloxane crosslinked product is resistant to ultraviolet rays and has high strength. Therefore, the reflective layer is suitably used for mounting the LED element.

In the reflective layer, the white ceramic particles are usually contained in an amount of 10% by mass or more and 90% by mass or less. When the amount of the white ceramic particles is in the above range, the reflectance of the reflective layer can be increased.

The thickness of the reflective layer is usually 5 μm or more and 200 μm or less. When the thickness is in the above range, the reflectance of the reflective layer can be increased.

Further, the reflectance of the reflective layer is usually 90% or more. When the reflectance is in the above range, it is suitably used as a reflective layer for mounting the LED element. Here, the reflectance is a value measured by the method described in the examples. By the way, in the conventional dielectric multilayer film, it is difficult to make the reflectance 90% or more. It is considered that this is because TiO ₂ absorbs light on the low wavelength side. In order to increase the reflectance, it is necessary to have multiple layers, but there is a problem that the cost increases. On the other hand, since the reflective substrate according to the embodiment uses white ceramic particles having a specific specific surface area and particle diameter, the reflectance can be improved.

The reflective layer may further contain other ceramic particles such as silicon carbide, silica, and the like, as long as the object of the present invention is not impaired.

<Manufacturing method of reflective substrate>
The method for manufacturing the reflective substrate includes a step of forming an electrodeposition layer on a metal substrate (electrodeposition layer forming step) and a step of forming the electrodeposition layer on the metal substrate by an electrophoresis electrodeposition method using an electrodeposition liquid. It includes a step of forming a reflective layer from the electrodeposition layer (a reflective layer forming step).

[Electrodeposition layer forming process]
The electrodeposition liquid used in the electrodeposition layer forming step contains the white ceramic particles and a component for forming the organopolysiloxane crosslinked body. The components for forming the organopolysiloxane crosslinked product include a metal alkoxide (A-1) or a hydrolyzed condensate of a metal alkoxide (A-2) and an organopolysiloxane (B) having a metal alkoxide at the end. include. In the present specification, the organopolysiloxane having the metal alkoxide at the end is also referred to as a modified organopolysiloxane (B).

Alkoxysilane is preferably used as the metal alkoxide (A-1). As the alkoxysilane, specifically, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, and tetra-n-butoxysilane are preferably used. .. The metal alkoxide (A-1) may be used alone or in combination of two or more.

As the hydrolyzed condensate (A-2) of the metal alkoxide (partially hydrolyzed oligomer of the metal alkoxide (A-1)), the hydrolyzed condensate of alkoxysilane (partially hydrolyzed oligomer of the alkoxysilane) is suitable. Used for. Specific examples of the hydrolyzed condensate of alkoxysilane include polymethylsilicate, polyethylsilicate, polypropoxysilicate, and polybutoxysilicate. Of these, polyethyl silicate is particularly preferably used. The hydrolyzed condensate of the metal alkoxide may be used alone or in combination of two or more. The metal alkoxide (A-1) and the hydrolyzed condensate of the metal alkoxide (A-2) may be used in combination.

The modified organopolysiloxane (B) is an organopolysiloxane in which one end or both ends of the main chain of the organopolysiloxane is modified with a metal alkoxide. Alternatively, the modified organopolysiloxane (B) is an organopolysiloxane in which one end or both ends of the main chain of the organopolysiloxane are modified with a hydrolysis condensate of a metal alkoxide (a partially hydrolyzed oligomer of a metal alkoxide). be. The organopolysiloxane before modification is represented by, for example, the following formula (1). The metal alkoxide used for modification and the hydrolyzed condensate of the metal alkoxide are represented by, for example, the following formulas (2), (3) or (4).

In the above formula (1), R ¹ and R ² are independently an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a cycloalkyl group, respectively. Specific examples of these include a methyl group, an ethyl group, a phenyl group, a benzyl group, a methylene group, an ethylene group, a cyclopropyl group and a cyclohexyl group. n is an integer of 2 or more.

As the organopolysiloxane before the modification, specifically, polydialkylsiloxane, polydiarylsiloxane, and polyalkylarylsiloxane are preferably used, and polydimethylsiloxane, polydiethylsiloxane, polydiphenylsiloxane, and polymethylphenylsiloxane, Polydiphenyldimethylsiloxane is more preferably used. As the organopolysiloxane before the modification, polydimethylsiloxane and polydiphenyldimethylsiloxane are particularly preferably used. The unmodified organopolysiloxane may be used alone or in combination of two or more.

In the above formulas (2) to (4), M is Si, Ti, Zr, or the like. R ³ , R ⁴ and R ⁵ are independently alkyl, aryl, aralkyl, alkenyl, or cycloalkyl groups, respectively. Specific examples of these include a methyl group, an ethyl group, a phenyl group, a benzyl group, a methylene group, an ethylene group, a cyclopropyl group and a cyclohexyl group. X and Y are each independently a hydrogen, an alkyl group, an aryl group, an aralkyl group, an alkenyl group, or a cycloalkyl group. Specific examples of these include a methyl group, an ethyl group, a phenyl group, a benzyl group, a methylene group, an ethylene group, a cyclopropyl group and a cyclohexyl group. When the component used for the above modification is a metal alkoxide, m is 1. When the component used for the above modification is a hydrolyzed condensate of metal alkoxide, m is an integer of 2 or more. In the above formulas (2) and (3), M may be Al. In this case, in the above formula (2), there is no -X and only -Y exists, and in the above formula (3), there is no -X and only -OR ⁴ exists.

Specifically, alkoxysilane is preferably used as the metal alkoxide used for the modification (modification) of the organopolysiloxane.

More specifically, the alkoxysilanes include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, and tetra-n-butoxysilane;
Trimethoxysilane, Methyltrimethoxysilane, Methyltriethoxysilane, Ethyltrimethoxysilane, Ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane Silane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, vinyltrimethoxysilane, vinyl Triethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3,3-trifluoropropyltri Methoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2- Hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isosianate Propyltrimethoxysilane, 3-Isocyanatopropyltriethoxysilane, 3- (meth) acrylicoxypropyltrimethoxysilane, 3- (meth) acrylicoxypropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyl Trialkylsilanes such as triethoxysilane;
Dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-i-propyldimethoxysilane, di-i-propyldiethoxy Silane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n-pentyldimethoxysilane, di-n-pentyldiethoxysilane, di-n-hexyldimethoxysilane, di-n-hexyldi Ethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane, di-n-octyldiethoxysilane, di-n-cyclohexyldimethoxysilane, di-n-cyclohexyl Examples thereof include dialkoxysilanes such as diethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane. As the alkoxysilane, tetramethoxysilane and trimethoxymethylsilane are particularly preferably used. The above alkoxysilane may be used alone or in combination of two or more.

Specifically, polymethylsilicate, polyethylsilicate, polypropoxysilicate, and polybutoxysilicate are preferably used as the hydrolyzed condensate of the metal alkoxide used for the modification (modification) of the organopolysiloxane. As the hydrolyzed condensate of the metal alkoxide, polyethyl silicate is particularly preferably used. The hydrolyzed condensate of the metal alkoxide may be used alone or in combination of two or more.

The mass average molecular weight of the modified organopolysiloxane is, for example, 8000 or more and 76000 or less.

The electrodeposition solution is a solvent such as dehydrated isopropyl alcohol, dehydrated n-propyl alcohol, dehydrated n-butyl alcohol, dehydrated isobutyl alcohol, dehydrated n-pentyl alcohol, dehydrated 2-pentyl alcohol, dehydrated 3-pentyl alcohol, monochloroacetic acid, It may further contain a stabilizer such as acetic acid.

The electrodeposition liquid is prepared, for example, by the following procedure. First, the white ceramic particles are heated and dried. Then, if necessary, a solvent and a stabilizer are added to the dried white ceramic particles, and the mixture is stirred to obtain a white ceramic particle-containing mixture. For stirring, for example, an ultrasonic homogenizer or an ultrasonic bath is used. The amounts of white ceramic particles, solvent and stabilizer, and stirring conditions are appropriately adjusted to obtain a suitable reflective layer.

Next, a component for forming an organopolysiloxane crosslinked body is added to the white ceramic particle-containing mixed solution. Specifically, the above-mentioned metal alkoxide (A-1) or the hydrolyzed condensate of the metal alkoxide (A-2) is mixed in advance with the modified organopolysiloxane (B) to form an organopolysiloxane crosslinked product. Ingredients (composition solution) for this purpose are prepared. A component (composition solution) for forming this organopolysiloxane crosslinked body is added to the white ceramic particle-containing mixture. Thereby, the electrodeposition liquid can be prepared.

In the electrodeposition layer forming step, the electrodeposition layer is formed on the metal substrate by the electrophoretic electrodeposition method using the electrodeposition liquid prepared as described above. 2 and 3 are diagrams for explaining an electrophoretic electrodeposition method using an electrodeposition liquid.

Specifically, the electrophoretic electrodeposition method is performed by the electrodeposition device 10. As shown in FIG. 2, the electrodeposition device 10 includes a container 12, electrodes 14a and 14b, and a power supply 16 connected to the electrodes 14a and 14b. The electrodeposition liquid 20 is put in the container 12, and the electrodes 14a and 14b are immersed in the electrodeposition liquid 20.

The electrode 14a is composed of the above-mentioned metal substrate. The electrode 14b is made of a stainless steel material, a carbon material, or the like. A positive voltage is applied to the electrode 14a, and a negative voltage is applied to the electrode 14b. Therefore, the electrode 14a serves as an anode and the electrode 14b serves as a cathode. In the present specification, the electrode 14a is also referred to as a metal substrate 14a.

White ceramic particles 22 are suspended in the electrodeposition liquid 20. When the electrodeposition solution using monochloroacetic acid as a stabilizer is used, the white ceramic particles 22 are charged with a negative charge in the electrodeposition solution 20. As shown in FIG. 3, the white ceramic particles 22 are attracted to the metal substrate 14a, which is an anode, by applying an electric field, and are fixed or deposited on the metal substrate 14a. Further, the component for forming the organopolysiloxane crosslinked body is also electrodeposited on the metal substrate 14a together with the white ceramic particles 22. Here, the component for forming the organopolysiloxane crosslinked product is in an uncured or semi-cured state. In this way, the electrodeposition layer 24 containing the white ceramic particles 22 and the components for forming the organopolysiloxane crosslinked body is formed on the metal substrate 14a.

By appropriately changing the current and voltage application time, characteristics such as the thickness of the finally obtained reflective layer can be adjusted.

[Reflective layer forming step]
In the reflective layer forming step, the electrodeposited layer formed in the electrodeposition layer forming step is usually heated to form a reflective layer. The component for forming the organopolysiloxane crosslinked product in the electrodeposition layer is cured by a hydrolysis / dehydration polycondensation reaction in the presence of water to become an organopolysiloxane crosslinked product (cured product). By performing the firing in a normal atmosphere, the moisture in the air can be used as the moisture required for the reaction. In this way, a reflective layer containing white ceramic particles and an organopolysiloxane crosslinked body is formed on the metal substrate. In the reflective layer, the organopolysiloxane crosslinked body functions as a binder.

The heating temperature is, for example, more than room temperature (specifically, 20 ° C.) and 300 ° C. or lower. As the heating time, usually, the time until the hydrolysis / dehydration polycondensation reaction is completed is appropriately set. Further, the reflective layer may be formed at room temperature. In other words, the metal substrate on which the electrodeposition layer is formed may be left at room temperature for a period of time until the hydrolysis / dehydration polycondensation reaction is completed.

In the electrodeposition device 10 shown in FIG. 2, the electrodeposition layer 24 is formed on the surface of the metal substrate 14a facing the electrode 14b. Therefore, when the electrodeposition layers 24 are formed on both surfaces of the metal substrate 14a, the orientation of the metal substrate 14a may be turned inside out. Alternatively, the two electrodes 14b may be arranged so as to face both sides of the metal substrate 14a. In this case, a reflective layer containing white ceramic particles and an organopolysiloxane crosslink is finally formed on both sides of the metal substrate.

The component for forming the organopolysiloxane crosslinked product may be referred to as a raw material liquid for an organopolysiloxane-based organic / inorganic hybrid material. Further, the organopolysiloxane crosslinked product may be referred to as an organopolysiloxane-based organic / inorganic hybrid material.

<LED package>
The LED package according to the embodiment includes the above-mentioned reflection substrate and the LED element mounted on the above-mentioned reflection substrate. FIG. 4 is a plan view of the LED package according to the embodiment. FIG. 5 is a cross-sectional view taken along the line AA'of FIG.

The LED package 100 has a reflective substrate 30 as described above. The reflective substrate 30 has a metal substrate 32 and a reflective layer 34 formed on the metal substrate 32. Further, the LED package 100 is composed of a printed wiring board 36, a dam material 38, an LED element 40, a phosphor resin 42, and the like. The printed wiring board 36 is composed of a base 36a, electrodes 36b (electrodes 36b-1, 36b-2), and a resist 36c.

The LED element 40 is bonded and mounted by a die bond material 46 to a region (element mounting area 44) partitioned by a dam material 38 arranged in a substantially circular shape with a silicone resin or the like. In the element mounting region 44, the reflective layer 34 is laminated on the metal substrate 32. Therefore, the LED element 40 is adhered to the surface of the reflective layer 34. The printed wiring board 36 is adhered to the periphery of the element mounting area 44 by an adhesive sheet 48.

In the element mounting area 44, three groups of LED elements 40 connected in series by 12 are connected in parallel between the electrodes 36b-1 and the electrodes 36b-2 on the printed wiring board 36. A gold wire 50 is usually used for connection. When a predetermined voltage is supplied between the electrodes 36b-1 and the electrodes 36b-2, the LED element 40 emits light.

A phosphor resin 42 for protecting the LED element 40 exists inside the dam material 38 around the LED element 40. For the phosphor resin 42, for example, a transparent epoxy resin or a silicone resin is used. The phosphor resin 42 contains a phosphor together with the resin. The phosphor absorbs a part of the blue light emitted from the LED element 40 and emits the wavelength-converted yellow light. Therefore, blue light and yellow light are mixed, and white light is emitted from the LED package 100.

As described above, the reflective layer 34 contains the white ceramic particles and the organopolysiloxane crosslinked product, and therefore has a high reflectance. Therefore, the LED package 100 can efficiently utilize the light emission of the LED element 40.

In the LED package 100 according to the embodiment, 12 LED elements 40 of 3 groups connected in series are connected in parallel. However, the number of LED elements 40 connected in series and the number of groups connected in parallel are not limited to this.

Further, FIG. 6 is a cross-sectional view of a modified example of the LED package according to the embodiment. In the modified example shown in FIG. 6, the reflective layer 34 is provided on the entire surface of the metal substrate 32, and the printed wiring board 36 is adhered on the reflective layer 34 by the adhesive sheet 48. Since other points are the same as the LED package according to the embodiment shown in FIGS. 4 and 5, the description thereof will be omitted. In the modified example, the light emission of the LED element can be efficiently utilized. Further, the base 36a and the reflective layer 34 are laminated, and both of them play the role of an insulating substrate, so that the withstand voltage is improved. In addition, masking is not required in the manufacture of the LED package, and batch processing can be performed, which is advantageous in terms of production (cost).

Further, the LED package according to the embodiment may be an LED package having the following configuration. FIG. 7 is a cross-sectional view of the LED package according to another embodiment. The LED package 200 according to another embodiment has a reflective substrate 60 as described above. The reflective substrate 60 has a metal substrate 62 and a reflective layer 64 formed on the metal substrate 62. Further, the LED package 200 is composed of a wiring 66, an LED element 68 electrically joined to the wiring 66, and the like. Although not shown, in the LED package 200, the wiring 66 and the LED element 68 may be molded with a phosphor resin. When a predetermined voltage is supplied to the wiring 66, the LED element 68 emits light.

As described above, the reflective layer 64 contains the white ceramic particles and the organopolysiloxane crosslinked product, and therefore has a high reflectance. Therefore, the LED package 200 can efficiently utilize the light emission of the LED element 68.

In the LED package according to the embodiment, a "pseudo-white light emitting type" in which a blue LED element and a yellow phosphor are combined has been described as an example. However, it is not limited to this. The LED package according to the embodiment may be, for example, a "ultraviolet to near-ultraviolet light source type" in which an ultraviolet to near-ultraviolet LED element and a red phosphor, a green phosphor, a blue phosphor and the like are combined. Further, it may be an "RGB light source type" that emits white light from three light sources of a red LED element, a green LED element, and a blue LED element.

The above-mentioned reflective substrate can be suitably applied to other devices other than the LED package. As a result, the reflectance can be improved even in the above device.

Based on the above, the present invention relates to the following.
[1] A reflective substrate having a metal substrate and a reflective layer formed on the metal substrate. The reflective layer contains white ceramic particles and an organopolysiloxane bridge, and the white ceramic particles have a specific surface area. A reflective substrate having a surface area of 6 m ² / g or more and 50 m ² / g or less and a particle size of 0.2 μm or more and 2 μm or less.
The reflective substrate has a large reflectance.
[2] A step of forming an electrodeposition layer containing white ceramic particles and a component for forming an organopolysiloxane crosslinked body on a metal substrate by an electrophoresis electrodeposition method using an electrodeposition liquid, and the above metal substrate. The electrodeposition solution comprises the steps of forming a reflective layer containing the white ceramic particles and the organopolysiloxane crosslinked product from the electrodeposited layer formed above, and the electrodeposition solution comprises the white ceramic particles and the organopolysiloxane crosslink. The white ceramic particles have a specific surface area of 6 m ² / g or more and 50 m ² / g or less, a particle size of 0.2 μm or more and 2 μm or less, and include the components for forming a body, and the organopolysiloxane crosslinks. A method for producing a reflective substrate, wherein the component for forming the body contains a metal alkoxide or a hydrolysis condensate of the metal alkoxide, and an organopolysiloxane having the metal alkoxide at the end.
According to the above-mentioned method for manufacturing a reflective substrate, a reflective substrate having a large reflectance can be obtained.
[3] An electrodeposition solution for forming a reflective layer on a metal substrate by an electrophoresis electrodeposition method, which contains white ceramic particles and a component for forming an organopolysiloxane crosslinked body, and is white. The ceramic particles have a specific surface area of 6 m ² / g or more and 50 m ² / g or less, a particle size of 0.2 μm or more and 2 μm or less, and the component for forming the organopolysiloxane bridge is metal alkoxide or the above. An electrodeposition liquid comprising a hydrolyzed condensate of a metal alkoxide and an organopolysiloxane having a metal alkoxide at the end.
By using the electrodeposition liquid, a reflective substrate having a large reflectance can be manufactured.
[4] An LED package comprising the reflective substrate according to [1] and an LED element mounted on the reflective substrate.
Since the LED package has the reflective substrate, the light emission of the LED element can be efficiently utilized.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.

[Example]

[Example 1-1]
(Preparation of zirconia particle-containing mixture)
First, spherical zirconia (ZrO ₂ ) particles were prepared. The zirconia particles had a specific surface area of 8 m ² / g and a particle diameter of 0.55 μm. The zirconia particles were dried at 130 ° C. for 1 hour. Next, dehydrated isopropyl alcohol (IPA, manufactured by Wako Pure Chemical Industries, Ltd., 2-propanol (ultra-dehydrated)) and monochloroacetic acid (MCAA, manufactured by Wako Pure Chemical Industries, Ltd., Chloroacetic Acid) were added to the zirconia particles. Here, the obtained solution was blended with a concentration of 15% by mass of zirconia particles, 12.75% by mass of MCAA, and 72.25% by mass of dehydrated IPA.
Next, the above solution was subjected to ultrasonic homogenizer treatment with UP100H manufactured by hielscher for 3 minutes and ultrasonic bath treatment with FU-3H manufactured by Fine for 1 hour. These treatments were carried out while stirring the above solution so that the zirconia particles were uniformly mixed in the dehydrated IPA and MCAA. As a result, a zirconia particle-containing mixture was obtained.

(Preparation of components for forming an organopolysiloxane crosslink)
Ethyl silicate terminal-modified polydimethylsiloxane (hereinafter, also referred to as ES-PDMS-B) and ethyl silicate (hereinafter, also referred to as ES) are mixed to prepare a component for forming an organopolysiloxane crosslinked product. did.
ES-PDMS-B has a mass average molecular weight of 22000 and is represented by the following formula (5). ES-PDMS-B was prepared by the method described in JP-A-2016-65234. Further, ES is represented by the following formula (6). Here, in the following equations (5) and (6), n is an integer of 8 or more and 10 or less.

(Preparation of electrodeposition liquid)

While stirring the zirconia particle-containing mixture, a component for forming an organopolysiloxane crosslinked body was added to obtain an electrodeposited liquid. As an example of compounding, ES and ES-PDMS-B are 5.1 g and 15.1 g, respectively, with respect to 100 g of the above-mentioned zirconia particle-containing mixed solution.

(Electrodeposition layer forming process)
The electrodeposition layer 24 was formed on the aluminum substrate 14a by the electrophoretic electrodeposition method using the electrodeposition liquid 20 (FIGS. 2 and 3).
Specifically, the electrophoresis electrodeposition method was performed by the electrodeposition device 10. The electrodeposition liquid 20 was placed in the container 12, and the aluminum substrate 14a and the stainless steel material 14b were immersed in the electrodeposition liquid 20. Here, as the power supply device 16, Pro-3900 manufactured by Anatech was used.
The zirconia particles 22 in the electrodeposition liquid 20 were fixed or deposited on the aluminum substrate 14a by applying an electric field. Further, the component for forming the organopolysiloxane crosslinked body was also electrodeposited on the aluminum substrate 14a together with the white zirconia particles 22. In this way, the electrodeposition layer 24 containing the zirconia particles 22 and the components for forming the organopolysiloxane crosslinked body was formed on the aluminum substrate 14a.
The electrodeposition was performed by keeping the current constant and appropriately adjusting the electrodeposition time so that the film of the electrodeposition layer 24 was 50 μm.

(Reflective layer forming process)
A reflective layer was formed from the electrodeposition layer 24 formed on the aluminum substrate 14a. Specifically, the aluminum substrate 14a on which the electrodeposition layer 24 was formed was heated at 250 ° C. for 2 hours. Here, the component for forming the organopolysiloxane crosslinked body was cured by a hydrolysis / dehydration polycondensation reaction by heating to become an organopolysiloxane crosslinked body (cured body). In this way, a reflective layer containing the zirconia particles 22 and the organopolysiloxane crosslinked product was formed.
As described above, a reflective substrate having an aluminum substrate and a reflective layer formed on the aluminum substrate was produced.

[Example 1-2]
A reflective substrate was prepared in the same manner as in Example 1-1 except that zirconia particles having a specific surface area of 13 m ² / g and a particle diameter of 0.55 μm were used.

[Example 1-3]
A reflective substrate was produced in the same manner as in Example 1-1 except that zirconia particles having a specific surface area of 36 m ² / g and a particle diameter of 0.55 μm were used.

[Comparative Example 1-1]
A reflective substrate was prepared in the same manner as in Example 1-1 except that zirconia particles having a specific surface area of 54 m ² / g and a particle size of 0.55 μm were used.

[Comparative Example 1-2]
A reflective substrate was prepared in the same manner as in Example 1-1 except that zirconia particles having a specific surface area of 68 m ² / g and a particle diameter of 0.55 μm were used.

[Comparative Example 1-3]
A reflective substrate was produced in the same manner as in Example 1-1 except that zirconia particles having a specific surface area of 82 m ² / g and a particle size of 0.55 μm were used.

[Example 2-1]
A reflective substrate was prepared in the same manner as in Example 1-1 except that the zirconia particles having a specific surface area of 10 m ² / g and a particle diameter of 0.2 μm were used.

[Example 2-2]
A reflective substrate was prepared in the same manner as in Example 1-1 except that zirconia particles having a specific surface area of 6.5 m ² / g and a particle size of 2 μm were used.

[Comparative Example 2-1]
A reflective substrate was prepared in the same manner as in Example 1-1 except that zirconia particles having a specific surface area of 10 m ² / g and a particle diameter of 17 μm were used.

<Reflectance>
The total reflectance (d / 8 SCI) of the produced reflective substrate was measured using a spectrocolorimeter CM-2600d (manufactured by Konica Minolta Sensing Co., Ltd.) with a wavelength of 360 nm or more and 740 nm or less. This value was taken as the reflectance. The obtained results are shown in Table 1, Table 2 and FIGS. 8 and 9.

(Particle diameter: 0.55 μm)

FIG. 8 shows the results of the reflectances of Examples 1-1 to 1-3 and Comparative Examples 1-1 to 1-3. When fitting with a quadratic curve (y = -0.0022 x ² + 0.0431x + 93.287), it was found that the reflectance was 90% or more when the specific surface area of the white ceramic particles was 50 m ² / g or less. .. FIG. 9 shows the results of the reflectances of Examples 2-1, 1-1, 2-2 and Comparative Example 2-1. It was found that when the specific surface area of the white ceramic particles was 6 m ² / g or more and 50 m ² / g or less and the particle diameter was 0.2 μm or more and 2 μm or less, the reflectance was 90% or more.

1 Organopolysiloxane 2 Silica glass 10 Electrodeposition device 12 Container 14a, 14b Electrode 16 Power supply 20 Electrodeposition liquid 22 White ceramic particles 24 Electrodeposition layer 100, 200 LED package 30, 60 Reflection substrate 32, 62 Metal substrate 34, 64 Reflection Layer 36 Printed wiring board 36a Base 36b (36b-1, 36b-2) Electrode 36c Resist 38 Dam material 40, 68 LED element 42 Phosphoric resin 44 Element mounting area 46 Die bond material 48 Adhesive sheet 50 Gold wire 66 Wiring

Claims (2)

A method for manufacturing a reflective substrate having a metal substrate and a reflective layer formed on the metal substrate.
A step of forming an electrodeposition layer containing white ceramic particles and a component for forming an organopolysiloxane crosslinked body on the metal substrate by an electrophoresis electrodeposition method using an electrodeposition liquid, and a step on the metal substrate. The step of forming the reflective layer containing the white ceramic particles and the organopolysiloxane crosslinked product from the formed electrodeposition layer is included.
The electrodeposition liquid contains the white ceramic particles and a component for forming the organopolysiloxane crosslinked product.
The white ceramic particles are zirconia particles having a specific surface area of 6 m ² / g or more and 50 m ² / g or less and a particle diameter of 0.2 μm or more and 2 μm or less.
A method for producing a reflective substrate, wherein the component for forming the organopolysiloxane crosslinked product contains a metal alkoxide or a hydrolyzed condensate of the metal alkoxide, and an organopolysiloxane having a metal alkoxide at the end. An electrodeposition liquid for forming the reflective layer on the metal substrate by an electrophoretic electrodeposition method used for manufacturing a reflective substrate having a metal substrate and a reflective layer formed on the metal substrate.
It contains white ceramic particles and components for forming an organopolysiloxane crosslink.
The white ceramic particles are zirconia particles having a specific surface area of 6 m ² / g or more and 50 m ² / g or less and a particle diameter of 0.2 μm or more and 2 μm or less.
The component for forming the organopolysiloxane crosslinked product is an electrodeposition liquid containing a metal alkoxide or a hydrolyzed condensate of the metal alkoxide, and an organopolysiloxane having a metal alkoxide at the end.

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