JP2022047422A - Hardening body - Google Patents

Abstract

To provide: a hardening body exhibiting high light reflectance and good substrate adhesion; and a laminated structure, a reflective sheet, a printed wiring board, and a semiconductor device using the hardening body.SOLUTION: In a printed wiring board 1, in a hardening body (reflective sheet 3) of a resin composition containing an inorganic filler component containing at least a white inorganic pigment, which is provided on a substrate 2 having a conductor layer on at least a part of a surface thereof, when a non-volatile component in the hardening body is 100 mass%, a content of the white inorganic pigment is 20 mass% or more, and a surface 31 on a side not in contact with the substrate is defined as a first main surface, in a cross section of the hardening body in a direction perpendicular to the first main surface, an area A0-5 of the inorganic filler component per unit area in a region where a distance from the first main surface of the hardening body is 0 μm to 5 μm, and an area A5-10 of the inorganic filler component per unit area in a region where a distance from the first main surface is 5 μm to 10 μm satisfy A0-5/A5-10>1.1.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cured product. Further, the present invention relates to a laminated structure, a reflective sheet, a printed wiring board and a semiconductor device obtained by using the cured product.

In printed wiring boards, there are an increasing number of applications in which light emitting diodes (LEDs) that emit light with low power are directly mounted and used, such as backlights for liquid crystal displays of mobile terminals, computers, televisions, etc.; light sources for lighting equipment. In recent years, LEDs have been miniaturized, and there are LEDs called mini LEDs and micro LEDs.

A reflective sheet for reflecting light is formed on the outermost layer of such a printed wiring board in order to increase the efficiency of extracting light emitted from a light source.

As a material for such a reflective sheet, for example, Patent Document 1 discloses a resin composition containing crosslinked polymer particles containing a binder polymer and a white inorganic pigment.

Japanese Patent No. 5797279

By the way, as a result of studies by the present inventors, when a resin composition having a high content of white inorganic pigment is used in order to achieve high light reflectance, the adhesion between the obtained cured product and the conductor layer of the base substrate (hereinafter referred to as “adhesion”). , Simply referred to as "base adhesion") was found to be inferior. By suppressing the content of the white inorganic pigment, the adhesion to the substrate is somewhat improved, but in that case, the light reflectance is lowered.

An object of the present invention is to provide a cured product which exhibits high light reflectance and good substrate adhesion.

As a result of diligent studies to solve the above problems, the present inventors have made a resin component and an inorganic substance such as a white inorganic pigment in a region near the surface on the side not in contact with the underlying substrate when the substrate is provided. A cured product having a gradient (that is, a negative gradient of a certain value or more in the depth direction from the surface of the cured product) in the amount ratio (inorganic filler component / resin component) with the filler component has high light reflectance. It has been found that the present invention exhibits good adhesion to the substrate as well as the present invention, and has completed the present invention.

That is, the present invention includes the following contents.
[1] A cured product of a resin composition containing an inorganic filler component containing at least a white inorganic pigment, which is provided on a substrate having a conductor layer on at least a part of the surface thereof.
When the non-volatile component in the cured product is 100% by mass, the content of the white inorganic pigment is 20% by mass or more.
When the surface of the cured product on the side not in contact with the substrate is used as the first main surface,
Area A of the inorganic filler component per unit area in the region where the distance from the first main surface of the cured body is from 0 μm to 5 μm in the cross section of the cured body in the direction perpendicular to the first main surface of the cured body. _0-5 and the area A _5-10 of the inorganic filler component per unit area in the region where the distance from the first main surface is from 5 μm to 10 μm are A _0-5 / A _5-10 > 1. A cured product that satisfies 1.
[2] The cured product according to [1], further containing a thermosetting resin.
[3] The cured product according to [1] or [2], wherein the content of the white inorganic pigment is 20 to 60% by mass when the non-volatile component in the cured product is 100% by mass.
[4] The cured product according to [2] or [3], wherein the thermosetting resin contains an epoxy resin.
[5] The cured product according to [4], wherein the content of the epoxy resin is 10 to 50% by mass when the non-volatile component in the cured product is 100% by mass.
[6] The white inorganic pigment is one or more selected from aluminum oxide, titanium oxide, zirconium oxide, magnesium oxide, barium titanate, zinc oxide, cerium oxide, and calcium carbonate, [1] to [5]. The cured product described in any of them.
[7] The cured product according to any one of [1] to [6], which is used for an insulating layer of a printed wiring board or a solder resist layer.
[8] The cured product according to any one of [1] to [7], which is for light reflection.
[9] The cured product according to any one of [1] to [8], which has a reflectance of 80% or more with respect to light having a wavelength of 460 nm.
[10] A laminated structure including a substrate having a conductor layer on at least a part of the surface thereof and a cured product according to any one of [1] to [9] provided on the substrate.
[11] A reflective sheet containing the cured product according to any one of [1] to [9].
[12] A printed wiring board containing the reflective sheet according to [11] as an interlayer insulating layer or a solder resist.
[13] A printed wiring board containing the cured product according to any one of [1] to [9].
[14] A semiconductor device including the printed wiring board according to [12] or [13].

According to the present invention, it is possible to provide a cured product which exhibits high light reflectance and good substrate adhesion.

FIG. 1 is a schematic cross-sectional view showing an example of a printed wiring board.

Hereinafter, the present invention will be described in detail according to the preferred embodiment thereof. However, the present invention is not limited to the following embodiments and examples, and may be arbitrarily modified and implemented without departing from the scope of claims of the present invention and the equivalent scope thereof.

[Hardened body]
The cured product of the present invention is a resin containing an inorganic filler component containing at least a white inorganic pigment, which is provided on a substrate having a conductor layer on at least a part of the surface (hereinafter, also simply referred to as a “base substrate”). A cured product of the composition having a gradient (that is, a cured product) in the amount ratio (inorganic filler component / resin component) of the resin component and the inorganic filler component in the region near the surface on the side not in contact with the underlying substrate. It is characterized by having a negative gradient of a certain value or more from the surface toward the depth direction).

In the following description, of the two main surfaces (surfaces) of the cured body, the main surface on the side not in contact with the base substrate is the "first main surface", and the main surface in contact with the base substrate is the "second main surface". It may be called "the main surface of".

In the cured product of the present invention, a phase rich in the inorganic filler component exists on the surface (first main surface) on the side not in contact with the underlying substrate, but a certain distance from the surface in the thickness direction. At the position, the proportion of the inorganic filler component is reduced. Here, the "thickness direction" refers to the thickness direction of the cured body, and represents the direction perpendicular to the first main surface of the cured body.

According to the cured product of the present invention in which an inorganic filler component-rich phase exists in a limited region near the first main surface, such an inorganic filler component-rich phase is expected from the bulk inorganic filler concentration. In addition to achieving a significantly higher light reflectance than that of the base substrate, a resin-rich phase exists in the region near the main surface (second main surface) in contact with the base substrate. It is presumed that it can exhibit excellent adhesion.

In the present invention, in expressing the gradient of the quantitative ratio of the inorganic filler component and the resin component in the region near the first main surface, the first aspect of the cured product in the direction perpendicular to the first main surface. The inorganic filler component area A _d1-d2 in the region where the distance from the main surface of 1 is from d1 (μm) to d2 (μm), and the distance from the first main surface is d2 (μm) to d3 (μm). The ratio (kA _d1-d2 / A _d2-d3 ) to the inorganic filler component area A _d2-d3 in the region up to) is used. Here, d1, d2 and d3 are numbers satisfying 0 ≦ d1 <d2 <d3 ≦ D, k is a coefficient satisfying k = | d2-d3 | / | d1-d2 |, and D is curing. Body thickness (μm).

In the present invention, the "inorganic filler component area" refers to the area occupied by the inorganic filler component, and the "inorganic filler component" includes other inorganic fillers such as silica in addition to the white inorganic pigment. .. Further, in the present invention, the "white inorganic pigment" refers to an inorganic compound or an inorganic filler having a reflectance of 90% or more with respect to light having a wavelength of 500 nm in one embodiment.

The ratio of the inorganic filler component area (kA _d1-d2 / A _d2-d3 ) can be measured by the method described in <Measurement of Inorganic Filler Component Area Ratio> described later. Specifically, it was obtained by (1) making a cross section so that the cross section perpendicular to the first main surface of the cured product was exposed to prepare a cross section sample, and (2) observing the cross section sample by SEM. Image analysis of the SEM image is performed to obtain the A _d1-d2 value and the A _d2-d3 value, and (3) the ratio (kA _d1-d2 / A _d2 ) from the obtained A _d1-d2 value and the A _d2-d3 value. _-D3 ) can be measured by a method including the calculation. In the image analysis, the resin component portion and the inorganic filler component portion are binarized, and the number of pixels of the inorganic filler component portion is treated as the inorganic filler component area. Further, when measuring the A _d1-d2 value and the A _d2-d3 value, the width of the measurement region (measurement distance in the direction parallel to the surface of the cured product) is set to be equal. As a result, the above ratio (kA _d1-d2 / A _d2-d3 ) is the area of the inorganic filler component per unit area in the region where the distance from the surface is from d1 (μm) to d2 (μm), and from the surface. Represents the ratio to the area of the inorganic filler component per unit area in the region where the distance is from d2 (μm) to d3 (μm). For example, in the measurement of the inorganic filler component area ratio A _0-5 / A _5-10 , d1 = 0 μm, d2 = 5 μm, d3 = 10 μm, and k = 1.

As a matter of course, when measuring the ratio of the component areas of the inorganic filler, the conditions are calibrated in order to ensure the accuracy of the image analysis. In such a calibration, the value of (the number of pixels of the inorganic filler component portion) / (the total number of pixels of the cross section of the cross-sectional sample) × 100 substantially matches the volume% value of the inorganic filler component of the cross-sectional sample. It can be carried out by setting a binarization threshold value.

In one preferred embodiment, the cured product of the present invention is:
A cured body of a resin composition containing an inorganic filler component containing at least a white inorganic pigment, which is provided on a substrate (“underlying substrate”) having a conductor layer on at least a part of the surface thereof.
When the non-volatile component in the cured product is 100% by mass, the content of the white inorganic pigment is 20% by mass or more.
Area A of the inorganic filler component per unit area in the region where the distance from the first main surface of the cured body is from 0 μm to 5 μm in the cross section of the cured body in the direction perpendicular to the first main surface of the cured body. _0-5 and the area A _5-10 of the inorganic filler component per unit area in the region where the distance from the first main surface is from 5 μm to 10 μm are A _0-5 / A _5-10 > 1. Satisfy 1. As described above, the "first main surface" means the surface of the cured product on the side not in contact with the base substrate.

From the viewpoint of achieving even better light reflectance and substrate adhesion, the cured product of the present invention is preferably A _0-5 / A _5-10 ≧ 1.15, more preferably A _0-5 / A ₅ . _-10 ≧ 1.2, more preferably A _0-5 / A _5-10 ≧ 1.22, A _0-5 / A _5-10 ≧ 1.24, or A _0-5 / A _5-10 ≧ 1 Satisfy .25.

The upper limit of the A _0-5 / A _5-10 ratio is not particularly limited, but is usually 10 or less, preferably 8 or less, 6 or less, or 5 or less.

When measuring the ratio of the component areas of the inorganic filler, if the first main surface of the cured product has irregularities, the center line of the irregularities (below the center line) in the thickness direction of the cured product (cross-sectional sample). When the sum of the areas of the valleys is S1 and the sum of the areas of the mountains above the center line is S2, an approximate straight line such that S1 = S2) is treated as the reference position of the "first main surface". ..

The thickness of the cured product of the present invention is preferably 200 μm or less, more preferably 150 μm, from the viewpoint of reducing the thickness of the printed wiring board and because the cured product of the present invention is excellent in light reflectance even if it is a thin film. It is less than or equal to 100 μm or less, more preferably 80 μm or less, 60 μm or less, or 50 μm or less. The lower limit of the thickness of the cured product is not particularly limited, but may be usually 10 μm or more, 15 μm or more, 20 μm or more, and the like.

The cured product of the present invention exhibits high light reflectance and good substrate adhesion. Therefore, the cured product of the present invention can be suitably used as a cured product for light reflection (cured body for light reflection) for reflecting light from a light source. Specifically, it can be suitably used as a cured body for a reflective sheet formed on the outermost layer of a printed wiring board. Examples of the light source include a light emitting diode (LED), a mini LED, a micro LED, and the like. Further, the cured product of the present invention can also be suitably used as a cured product for a solder resist layer of a printed wiring board (cured product for a solder resist layer). Therefore, the cured product of the present invention can be suitably used as a layer that also serves as both a solder resist layer and a reflective sheet. Further, the cured product of the present invention is also suitably used as a cured product for an insulating layer of a printed wiring board (cured product for an insulating layer), particularly as a cured product for an interlayer insulating material (cured product for an interlayer insulating layer). be able to.

The cured product of the present invention exhibits high light reflectance because it has a phase rich in the inorganic filler component in the region near the first main surface, and is preferably 80% or more, more preferably 80% or more, for example, with respect to light having a wavelength of 460 nm. Has a reflectance of 85% or more, more preferably 90% or more, 92% or more, 94% or more, or 95% or more. The upper limit of such light reflectance may be 100% or less. Therefore, in one preferred embodiment, the cured product of the present invention has a reflectance of 80% or more with respect to light having a wavelength of 460 nm. The light reflectance of the cured product can be measured using, for example, a multi-channel spectroscope (MCPD-7700, manufactured by Otsuka Electronics Co., Ltd.).

The cured product of the present invention can achieve such a high light reflectance without deterioration of the adhesion to the substrate. For example, the cured product of the present invention preferably has 0.4 kgf / cm or more, more preferably 0.42 kgf / cm or more, 0.44 kgf / cm or more, 0.45 kgf / cm or more, with respect to the conductor layer of the underlying substrate. It exhibits adhesion strength of 0.46 kgf / cm or more, 0.48 kgf / cm or more, or 0.5 kgf / cm or more. The upper limit of such adhesion strength may be 1 kgf / cm or less, 0.9 kgf / cm or less, or the like.

The cured product of the present invention is obtained by curing a resin composition containing an inorganic filler component containing at least a white inorganic pigment. Hereinafter, the resin composition used for forming the cured product of the present invention will be described, but the content of each component in the cured product of the present invention is the content of each component in the resin composition in the following description. In relation to the above, "when the non-volatile component in the resin composition is 100% by mass" may be read as "when the non-volatile component in the cured product is 100% by mass" and applied.

<Resin composition>
The cured product of the present invention is obtained by curing a resin composition containing an inorganic filler component containing at least a white inorganic pigment.

-White inorganic pigment-
As described above, the white inorganic pigment refers to an inorganic compound or an inorganic filler having a reflectance of 90% or more with respect to light having a wavelength of 500 nm in one embodiment.

From the viewpoint of realizing a cured product exhibiting high light reflectance, the content of the white inorganic pigment in the resin composition is preferably 20% by mass or more, preferably 20% by mass or more, when the non-volatile component in the resin composition is 100% by mass. Is 22% by mass or more, more preferably 24% by mass or more or 25% by mass or more.

In the cured product of the present invention in which the ratio of the component areas of the inorganic filler (A _0-5 / A _5-10 ) is in a specific range, the content of the white inorganic pigment is further increased without lowering the adhesion to the substrate. Can be done. For example, the content of the white inorganic pigment in the resin composition is 26% by mass or more, 28% by mass or more, 30% by mass or more, 32% by mass or more, 34% by mass or more, 36% by mass or more, 38% by mass or more, or It may be increased to 40% by mass or more.

The upper limit of the content of the white inorganic pigment in the resin composition is preferably 70% by mass or less, more preferably 65% by mass or less, still more preferably 60% by mass or less, or 55 from the viewpoint of achieving good substrate adhesion. It is less than mass%.

In one preferred embodiment, when the non-volatile component in the resin composition is 100% by mass, the content of the white inorganic pigment is 20 to 60% by mass.

Examples of materials for white inorganic pigments are aluminum oxide (alumina), titanium oxide, zirconium oxide, magnesium oxide, zinc oxide, cerium oxide, antimony oxide, tin oxide, barium titanate, strontium titanate, calcium titanate, and titanium. White metal oxides such as magnesium acid, bismuth titanate, barium zirconate titanate, barium zirconate, calcium zirconate; white metal sulfides such as zinc sulfide and strontium sulfide; aluminum hydroxide, magnesium hydroxide, calcium hydroxide White metal hydroxides such as; white metal nitrides such as boron nitride, aluminum nitride, manganese nitride; white metal carbonates such as calcium carbonate, barium carbonate, magnesium carbonate, strontium carbonate, lead carbonate; barium sulfate, calcium sulfate, etc. White metal sulfates such as lead sulfate; white metal phosphates such as zinc phosphate, titanium phosphate, zirconium phosphate, zirconium tungstate phosphate; white metal borates such as aluminum borate; cordierite, talc , Clay, mica, hydrotalcite, white minerals such as boehmite and the like.

Among these, the white inorganic pigment is preferably selected from aluminum oxide, titanium oxide, zirconium oxide, magnesium oxide, barium titanate, zinc oxide, cerium oxide, and calcium carbonate, and titanium oxide is particularly preferable. As the titanium oxide, any of a rutile type, anatase type, and brookite type may be used, but the rutile type is preferable from the viewpoint of further improving the reflectance. As the titanium oxide, those obtained by a method such as a sulfuric acid method or a chlorine method can be used. The material of the white inorganic pigment may be one kind alone or a mixture of two or more kinds. The shape of the white inorganic pigment may be, for example, an indefinite shape, a crushed shape, a scaly shape, or a spherical shape.

Commercially available white inorganic pigments include, for example, "PX3788" manufactured by Sakai Chemical Industry Co., Ltd .; Typake "CR-50", "CR-57", "CR-80", "CR-90" manufactured by Ishihara Sangyo Co., Ltd. , "CR-93", "CR-95", "CR-97", "CR-60", "CR-63", "CR-67", "CR-58", "CR-85", " UT771 "; Typure" R-100 "," R-101 "," R-102 "," R-103 "," R-104 "," R-105 "," R-108 ", manufactured by DuPont. "R-900", "R-902", "R-960", "R-706", "R-931"; Nippon Light Metal Co., Ltd. "AHP300"; Showa Denko Co., Ltd. Arna beads "CB-P05", " CB-A30S "and the like.

The specific surface area of the white inorganic pigment is preferably 0.5 m ² / g or more, more preferably 1 m ² / g or more, and particularly preferably 2 m ² / g or more. The upper limit is not particularly limited, but is preferably 80 m ² / g or less, 70 m ² / g or less, or 60 m ² / g or less. The specific surface area is obtained by adsorbing nitrogen gas on the sample surface using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech) according to the BET method and calculating the specific surface area using the BET multipoint method. ..

The average particle size of the white inorganic pigment is preferably 0.01 μm or more, more preferably 0.05 μm or more, still more preferably 0.1 μm or more, and preferably 10 μm from the viewpoint of remarkably obtaining the desired effect of the present invention. Below, it is more preferably 5 μm or less, still more preferably 2 μm or less or 1 μm or less.

The average particle size of the white inorganic pigment can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, it can be measured by creating a particle size distribution of a white inorganic pigment on a volume basis using a laser diffraction / scattering type particle size distribution measuring device and using the median diameter as the average particle size. As the measurement sample, 100 mg of a white inorganic pigment and 10 g of methyl ethyl ketone can be weighed in a vial and dispersed by ultrasonic waves for 10 minutes. The measurement sample was measured using a laser diffraction type particle size distribution measuring device, the light source wavelengths used were blue and red, and the volume-based particle size distribution of the white inorganic pigment was measured by the flow cell method. The average particle size can be calculated as the median diameter. Examples of the laser diffraction type particle size distribution measuring device include "LA-960" manufactured by HORIBA, Ltd.

The white inorganic pigment is preferably treated with a surface treatment agent from the viewpoint of enhancing moisture resistance and dispersibility. One type of surface treatment agent may be used alone, or two or more types may be used in any combination. Examples of the surface treatment agent include vinyl-based silane coupling agents, epoxy-based silane coupling agents, styryl-based silane coupling agents, (meth) acrylic-based silane coupling agents, amino-based silane coupling agents, and isocyanurate-based silanes. Silane couplings such as coupling agents, ureido-based silane coupling agents, mercapto-based silane coupling agents, isocyanate-based silane coupling agents, acid anhydride-based silane coupling agents, alkylsilane coupling agents, and phenylsilane coupling agents. Agents are mentioned. The surface treatment agent does not contain nitrogen atoms from the viewpoint of improving the reflectance and from the viewpoint of easily realizing a cured product in which the ratio of the component areas of the inorganic filler (A _0-5 / A _5-10 ) is in a specific range (A 0-5 / A 5-10). It is preferably a surface treatment agent (free of nitrogen atoms), and more preferably a silane coupling agent containing no nitrogen atoms (free of nitrogen atoms). Examples of the silane coupling agent containing no nitrogen atom (without nitrogen atom) include a phenylsilane coupling agent, an alkylsilane coupling agent, an epoxy-based silane coupling agent, a vinyl-based silane coupling agent, and a (meth) acrylic-based agent. Examples thereof include a silane coupling agent selected from a silane coupling agent and a styryl-based silane coupling agent.

Examples of the phenylsilane coupling agent include phenyltrimethoxysilane and phenyltriethoxysilane. Examples of the alkylsilane coupling agent include methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, and hexyltri. Examples thereof include ethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, and 1,6-bis (trimethoxysilyl) hexane. Examples of the epoxy-based silane coupling agent include 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycid. Examples thereof include xypropylmethyldiethoxysilane and 3-glycidoxypropyltriethoxysilane.

Examples of the vinyl-based silane coupling agent include vinyltrimethoxysilane and vinyltriethoxysilane. Examples of the (meth) acrylic silane coupling agent include 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane. , 3-Acryloxypropyltrimethoxysilane and the like. Examples of the styryl-based silane coupling agent include p-styryltrimethoxysilane.

Commercially available surface treatment agents include, for example, "KBM-103" and "KBE-103" (phenylsilane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd .; "KBM-13", "KBM-22", and "KBE". -13, "KBE-22", "KBM-3033", "KBE-3033", "KBM-3063", "KBE-3063", "KBE-3083", "KBM-3103C", "KBM-3066" , "KBM-7103" (alkylsilane coupling agent); "KBM-1003", "KBE-1003" (vinyl-based silane coupling agent); "KBM-303", "KBM-402", "KBM-" 403 "," KBE-402 "," KBE-403 "(epoxy-based silane coupling agent);" KBM-1403 "(styryl-based silane coupling agent);" KBM-502 "," KBM-503 "," Examples thereof include "KBE-502", "KBE-503", and "KBM-5103" ((meth) acrylic silane coupling agent).

The degree of surface treatment with the surface treatment agent is preferably within a predetermined range from the viewpoint of improving the dispersibility of the white inorganic pigment. Specifically, 100 parts by mass of the white inorganic pigment is preferably surface-treated with 0.2 parts by mass to 5 parts by mass of a surface treatment agent, and is surface-treated with 0.2 parts by mass to 3 parts by mass. It is preferable that the surface is treated with 0.3 parts by mass to 2 parts by mass.

The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the white inorganic pigment. The amount of carbon per unit surface area of the white inorganic pigment is preferably 0.02 mg / m ² or more, more preferably 0.1 mg / m ^{2 or more, and 0.2 mg / m 2 from} the viewpoint of improving the dispersibility of the white inorganic pigment. The above is more preferable. On the other hand, from the viewpoint of suppressing an increase in the melt viscosity of the resin varnish and the melt viscosity in the sheet form, 1 mg / m ² or less is preferable, 0.8 mg / m ² or less is more preferable, and 0.5 mg / m ² or less is further preferable. preferable.

The amount of carbon per unit surface area of the white inorganic pigment can be measured after the surface-treated white inorganic pigment is washed with a solvent (for example, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the white inorganic pigment surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25 ° C. for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the white inorganic pigment can be measured using a carbon analyzer. As the carbon analyzer, "EMIA-320V" manufactured by HORIBA, Ltd. or the like can be used.

-Other inorganic fillers-
The resin composition may contain other inorganic fillers as long as it contains at least a white inorganic pigment. The other inorganic filler is not particularly limited as long as it is an inorganic filler different from the white inorganic pigment, and for example, an inorganic filler having a reflectance of less than 90% for light having a wavelength of 500 nm may be used.

Among them, silica is preferable as another inorganic filler from the viewpoint that it is easy to realize a cured product in which the ratio of the component areas of the inorganic filler (A _0-5 / A _5-10 ) is in a specific range. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica and the like. Further, as silica, spherical silica is preferable. The specific surface area and average particle size of silica are the same as those of the white inorganic pigment. One type of silica may be used alone, or two or more types may be used in combination.

Examples of commercially available silica products include "UFP-30" manufactured by Denka Co., Ltd .; "SP60-05" and "SP507-05" manufactured by Nittetsu Chemical & Materials Co., Ltd .; "YC100C" and "YA050C" manufactured by Admatex Co., Ltd. , "YA050C-MJE", "YA010C"; "Silfil NSS-3N", "Silfil NSS-4N", "Silfil NSS-5N" manufactured by Tokuyama; "SC2500SQ", "SO-C4" manufactured by Admatex. , "SO-C2", "SO-C1"; and the like.

Other inorganic fillers such as silica are preferably treated with a surface treatment agent from the viewpoint of enhancing moisture resistance and dispersibility. Examples of the surface treatment agent include those similar to the surface treatment agent in the white inorganic pigment. The degree of surface treatment of other inorganic fillers with the surface treatment agent is the same as that of the white inorganic pigment.

The content of the other inorganic filler in the resin composition is preferably 1% by mass or more, more preferably 1% by mass or more, when the non-volatile component in the resin composition is 100% by mass from the viewpoint of remarkably obtaining the effect of the present invention. Is 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 15% by mass or more. The upper limit of the content of the other inorganic filler is preferably 70% by mass or less, more preferably 50% by mass or less, still more preferably 40% by mass or less, and particularly preferably 35% by mass or less.

The total content of the white inorganic pigment and other inorganic fillers, that is, the total content of the inorganic filler components, is from the viewpoint of realizing a cured product having high light reflectance and good substrate adhesion. When the non-volatile component in the resin composition is 100% by mass, it is preferably 20% by mass or more, more preferably 30% by mass or more, further preferably 40% by mass or more, and particularly preferably 50% by mass or more, preferably 50% by mass or more. It is 90% by mass or less, more preferably 80% by mass or less, still more preferably 75% by mass or less, and particularly preferably 70% by mass or less.

The mass ratio of other inorganic fillers such as silica to the white inorganic pigment (mass of other inorganic fillers / mass of white inorganic pigments) realizes a cured product that exhibits high light reflectance and good substrate adhesion. From the viewpoint, it is preferably 0.1 or more, more preferably 0.2 or more, still more preferably 0.5 or more, particularly preferably 0.8 or more, preferably 4 or less, more preferably 4 or less, still more preferable. Is 2 or less, particularly preferably 1.5 or less.

The resin composition used for forming the cured product of the present invention contains a thermosetting resin as the resin. As the thermosetting resin, a conventionally known thermosetting resin used for forming the insulating layer of the printed wiring board can be used, and among them, the ratio of the component area of the inorganic filler (A _0-5 / A). Epoxy resin is preferable from the viewpoint that it is easy to realize a cured product in which _5-10 ) is in a specific range. Therefore, in one embodiment the resin composition comprises a thermosetting resin and in one preferred embodiment the thermosetting resin comprises an epoxy resin.

-Epoxy resin-
The epoxy resin means a curable resin having an epoxy group. One type of epoxy resin may be used alone, or two or more types may be used in combination.

Examples of the epoxy resin include bixilenol type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, hydrogenated bisphenol A type epoxy resin, and dicyclopentadiene type epoxy. Resin, Trisphenol type epoxy resin, naphthol novolac type epoxy resin, phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, Glycidyl ester type epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro Ring-containing epoxy resin, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, naphthylene ether type epoxy resin, trimethylol type epoxy resin, tetraphenylethane type epoxy resin, isocyanurate type epoxy resin, phenolphthalimidine type epoxy Examples thereof include resins and phenolphthaline type epoxy resins.

The resin composition preferably contains, as the epoxy resin, an epoxy resin having two or more epoxy groups in one molecule. The ratio of the epoxy resin having two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass with respect to 100% by mass of the non-volatile component of the epoxy resin. % Or more.

The epoxy resin includes a solid epoxy resin at a temperature of 25 ° C. (hereinafter, also referred to as “solid epoxy resin”) and a liquid epoxy resin at a temperature of 25 ° C. (hereinafter, also referred to as “liquid epoxy resin”). There is. The resin composition used for forming the cured product of the present invention may contain only a solid epoxy resin, may contain only a liquid epoxy resin, or may contain only a liquid epoxy resin, or may be a solid epoxy resin. It may be contained in combination with a liquid epoxy resin.

As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferable, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferable.

Examples of the solid epoxy resin include bixilenol type epoxy resin, naphthalene type epoxy resin, naphthalene type tetrafunctional epoxy resin, naphthol novolac type epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, and trisphenol type epoxy resin. Naftor type epoxy resin, biphenyl type epoxy resin, naphthylene ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, phenol aralkyl type epoxy resin, tetraphenylethane type epoxy resin, phenol phthali Midin type epoxy resin and phenol phthalein type epoxy resin are preferable.

Specific examples of the solid epoxy resin include "HP4032H" (naphthalene type epoxy resin) manufactured by DIC; "HP-4700" and "HP-4710" (naphthalen type tetrafunctional epoxy resin) manufactured by DIC; DIC. "N-690" (cresol novolac type epoxy resin); DIC "N-695" (cresol novolac type epoxy resin); DIC "HP-7200", "HP-7200HH", "HP" -7200H "," HP-7200L "(dicyclopentadiene type epoxy resin);" EXA-7311 "," EXA-7311-G3 "," EXA-7311-G4 "," EXA-7311-G4S "manufactured by DIC. , "HP6000" (naphthylene ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd .; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nihon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd .; "ESN475V" (naphthalene type epoxy resin) manufactured by Nittetsu Chemical & Materials Co., Ltd.; "ESN485" (naphthol type epoxy resin) manufactured by Nittetsu Chemical &Materials; "ESN375" (dihydroxynaphthalene type epoxy resin) manufactured by Nittetsu Chemical &Materials; "YX4000H", "YX4000", manufactured by Mitsubishi Chemical Co., Ltd. "YX4000HK", "YL7890" (bixilenol type epoxy resin); "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd .; "YX8800" (anthracen type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd. "YX7700" (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemical Co., Ltd .; "YX7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd .; "YL7800" (fluorene type epoxy resin); "jER1010" manufactured by Mitsubishi Chemical Co., Ltd. (bisphenol A type epoxy resin); "jER1031S" manufactured by Mitsubishi Chemical Co., Ltd. (tetraphenylethane type epoxy resin); WHR991S ”(phenol phthalimidine type epoxy resin) and the like can be mentioned. These may be used individually by 1 type, or may be used in combination of 2 or more types.

As the liquid epoxy resin, a liquid epoxy resin having two or more epoxy groups in one molecule is preferable.

Examples of the liquid epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, hydrogenated bisphenol A type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, and phenol. A novolak type epoxy resin, an alicyclic epoxy resin having an ester skeleton, a cyclohexane type epoxy resin, a cyclohexanedimethanol type epoxy resin, and an epoxy resin having a butadiene structure are preferable.

Specific examples of the liquid epoxy resin include "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC; "828US", "828EL", "jER828EL", and "825" manufactured by Mitsubishi Chemical Co., Ltd. , (Bisphenol A type epoxy resin); "jER807", "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd .; "jER152" (phenol novolak type epoxy resin) manufactured by Mitsubishi Chemical Co., Ltd.; "630", "630LSD", "604" (glycidylamine type epoxy resin); "ED-523T" (glycylol type epoxy resin) manufactured by ADEKA; "EP-3950L", "EP-3980S" manufactured by ADEKA. (Glysidylamine type epoxy resin); "EP-4088S" (dicyclopentadiene type epoxy resin) manufactured by ADEKA; "ZX1059" (bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nittetsu Chemical & Materials Co., Ltd. (Mixed product); "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase Chemtex Co., Ltd .; "Selokiside 2021P" (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Co., Ltd .; "PB" manufactured by Daisel Co., Ltd. -3600 "," JP-100 "," JP-200 "(epoxy resin having a butadiene structure) manufactured by Nippon Soda Co., Ltd .;" ZX1658 "," ZX1658GS "(1,4-glycidyl) manufactured by Nittetsu Chemical & Materials Co., Ltd. Cyclohexane type epoxy resin), "YX8000" manufactured by Mitsubishi Chemical Co., Ltd. (hydrogenated bisphenol A type epoxy resin), "KF-101" manufactured by Shinetsu Chemical Co., Ltd. (epoxy-modified silicone resin), and the like. These may be used individually by 1 type, or may be used in combination of 2 or more types.

The epoxy resin may be a solid epoxy resin, a liquid epoxy resin, or a combination thereof, but the curing is such that the ratio of the component areas of the inorganic filler (A _0-5 / A _5-10 ) is within a specific range. From the viewpoint of easy realization of the body, it is preferable to contain a solid epoxy resin, and a combination of the solid epoxy resin and the liquid epoxy resin is particularly preferable.

When a solid epoxy resin and a liquid epoxy resin are used in combination as the epoxy resin, their mass ratio (solid epoxy resin: liquid epoxy resin) is preferably 20: 1 to 1:20, more preferably 10:20. It is 1 to 1:10, particularly preferably 3: 1 to 1: 3.

The epoxy equivalent of the epoxy resin is preferably 50 g / eq. ~ 5,000 g / eq. , More preferably 60 g / eq. ~ 1,000 g / eq. , More preferably 80 g / eq. ~ 500 g / eq. , Even more preferably 100 g / eq. ~ 300 g / eq. Is. Epoxy equivalent is the mass of resin per equivalent of epoxy group. This epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of the epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight average molecular weight of the resin can be measured as a polystyrene-equivalent value by a gel permeation chromatography (GPC) method.

The content of the epoxy resin is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably, when the non-volatile component in the resin composition is 100% by mass, from the viewpoint of remarkably obtaining the effect of the present invention. Is 10% by mass or more, particularly preferably 15% by mass or more, preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 35% by mass or less, and particularly preferably 30% by mass or less. Therefore, in one preferred embodiment, the content of the epoxy resin is 10 to 50% by mass when the non-volatile component in the resin composition is 100% by mass.

The resin composition used for forming the cured product of the present invention may further contain other components. Examples of such other components include curing agents, thermoplastic resins, curing accelerators, other additives, organic solvents and the like. Hereinafter, each component will be described in detail.

-Hardener-
The resin composition may contain a curing agent. The curing agent has a function of reacting with the epoxy resin to cure the resin composition. The curing agent may be used alone or in combination of two or more.

The curing agent is not particularly limited, but for example, a phenol-based curing agent, a carbodiimide-based curing agent, an acid anhydride-based curing agent, an amine-based curing agent, a benzoxazine-based curing agent, a cyanate ester-based curing agent, and the like. Examples include thiol-based curing agents. From the viewpoint of facilitating the realization of a cured product in which the ratio of the component areas of the inorganic filler (A _0-5 / A _5-10 ) is in a specific range, the curing agent preferably contains a phenolic curing agent.

The phenol-based curing agent is a curing agent having two or more phenolic hydroxyl groups in one molecule, and is, for example, a bisphenol-based curing agent, a biphenyl-type phenol-based curing agent, a naphthalene-type phenol-based curing agent, and a phenol novolac-type phenol-based. Hardener, naphthylene ether type phenolic hardener, triazine skeleton-containing phenolic hardener, polyphenylene ether type phenolic hardener, phenol aralkyl type phenolic hardener, cresol novolak type phenolic hardener, bisphenol type phenolic hardener And so on. Among them, a bisphenol-based curing agent is preferable, and a fluorine atom is more preferable, from the viewpoint of facilitating the realization of a cured product in which the ratio of the component areas of the inorganic filler (A _0-5 / A _5-10 ) is in a specific range. A bisphenol compound having an alicyclic structure, a bisphenol compound having a fluorene skeleton, a bisphenol-based curing agent selected from the above, more preferably a bisphenol compound having a fluorine atom, and particularly preferably a bisphenol AF.

Specific examples of commercially available phenolic curing agents include "BIS-AF" and "BIS-Z" manufactured by Central Glass Co., Ltd., "BisE" and "BisP-TMC" manufactured by Honshu Chemical Industry Co., Ltd .; Mitsui Chemical Fine Co., Ltd. "BisA", "BisF", "BisP-M" manufactured by Honshu Chemical Industry Co., Ltd. "BisP-AP", "BisP-MIBK", "BisP-B", "Bis-Z", "BisP-CP", "O, o'-BPF", "BisP-IOTD", "BisP-IBTD", "BisP-DED", "BisP-BA"; "Bis-C", "Bis26X-A" manufactured by Honshu Chemical Industry Co., Ltd., "BisOPP-A", "BisOTBP-A", "BisOCHP-A", "BisOFP-A", "BisOC-Z", "BisOC-FL", "BisOFP-A", "BisOC-CP", "BisOCHP" -Z "," Methylenebis P-CR "," TM-BPF "," BisOC-F "," Bis3M6B-IBTD "," BisOC-IST "," BisP-IST "," BisP-PRM "," BisP- LV ”and the like.

The carbodiimide-based curing agent is a curing agent having two or more carbodiimide structures in one molecule, and is an aliphatic such as tetramethylene-bis (t-butylcarbodiimide) and cyclohexanebis (methylene-t-butylcarbodiimide). Biscarbodiimide; Fragrant biscarbodiimide such as phenylene-bis (kisilylcarbodiimide); Polyhexamethylenecarbodiimide, Polytrimethylhexamethylenecarbodiimide, Polycyclohexylenecarbodiimide, Poly (methylenebiscyclohexylenecarbodiimide), Poly (isophorone) Carbodiimide) and other aliphatic polycarbodiimides; poly (phenylene carbodiimide), poly (naphthylene carbodiimide), poly (trilen carbodiimide), poly (methyldiisopropylphenylene carbodiimide), poly (triethylphenylene carbodiimide), poly (diethylphenylene carbodiimide) , Poly (triisopropylphenylene carbodiimide), poly (diisopropylphenylene carbodiimide), poly (xylylene carbodiimide), poly (tetramethylxylylene carbodiimide), poly (methylenediphenylene carbodiimide), poly [methylenebis (methylphenylene) carbodiimide], etc. Examples thereof include polycarbodiimides such as aromatic polycarbodiimides.

Commercially available products of carbodiimide-based curing agents include, for example, "carbodilite V-02B", "carbodilite V-03", "carbodilite V-04K", "carbodilite V-07" and "carbodilite V-09" manufactured by Nisshinbo Chemical Co., Ltd. "; Examples thereof include" Stavaxol P "," Stavaxol P400 ", and" High Kazil 510 "manufactured by Rheinchemy.

The acid anhydride-based curing agent is a curing agent having one or more carboxylic acid anhydride groups (-CO-O-CO-) in one molecule, and is, for example, phthalic anhydride, pyromellitic dianhydride, and the like. 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic acid dianhydride , Oxydiphthalic acid dianhydride, 3,3', 4,4'-diphenylsulfone tetracarboxylic acid dianhydride, 3,3', 4,4'-diphenyl ether tetracarboxylic acid dianhydride, 3,3', Aromatic acid anhydride-based curing agents such as 4,4'-biphenyltetracarboxylic acid dianhydride, methylene-4,4'-diphthalic acid dianhydride; tetrahydroanhydride, hexahydroanhydride, methyltetrahydrohydride. Acid, Methylhexahydroanhydride, Methylnagic acid anhydride, Hydrogenated methylnagic acid anhydride, Trialkyltetrahydroanhydride, Dodecenylhydride succinic acid, Cyclopentanetetracarboxylic acid dianhydride, Cyclohexane-1,2, Alipid acid anhydride-based curing agent such as 4,5-tetracarboxylic dianhydride; polymer anhydride such as styrene / maleic anhydride copolymer, alkyl (meth) acrylate / styrene / maleic anhydride copolymer Examples include physical hardeners. Commercially available acid anhydride curing agents include "HNA-100", "MH-700", "MTA-15", "DDSA", "OSA" manufactured by Shin Nihon Rika Co., Ltd., and "OSA" manufactured by Mitsubishi Chemical Corporation. Examples thereof include "YH-306" and "YH-307", "HN-2200" and "HN-5500" manufactured by Hitachi Chemical Co., Ltd.

The amine-based curing agent is a curing agent having two or more amino groups, and examples thereof include aliphatic amines, polyether amines, alicyclic amines, aromatic amines, and the like. Among them, the present invention. Aromatic amines are preferable from the viewpoint of exhibiting the desired effect of. The amine-based curing agent is preferably a primary amine or a secondary amine, more preferably a primary amine. Specific examples of the amine-based curing agent include 4,4'-methylenebis (2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, and 3,3'-diaminodiphenylsulfone. , M-phenylenediamine, m-xylylene diamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4' -Diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis (3-amino-4-hydroxyphenyl) propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2, 2-Bis (4-aminophenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-) Aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4-) (3-Aminophenoxy) phenyl) sulfone, etc. may be mentioned. Commercially available products may be used as the amine-based curing agent, for example, "SEIKACURE-S" manufactured by Seika, "KAYABOND C-200S", "KAYABOND C-100", and "Kayahard A-A" manufactured by Nippon Kayaku. , "Kayahard AB", "Kayahard AS", "Epicure W" manufactured by Mitsubishi Chemical Corporation, and the like.

Specific examples of the benzoxazine-based curing agent include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Co., Ltd .; "HFB2006M" manufactured by Showa High Polymer Co., Ltd .; "Pd" manufactured by Shikoku Chemicals Corporation. Examples include "FA".

Examples of the cyanate ester-based curing agent include bisphenol A dicyanate, polyphenol cyanate (oligo (3-methylene-1,5-phenylencianate)), 4,4'-methylenebis (2,6-dimethylphenylcyanate), and 4, 4'-Etilidene diphenyl disyanate, hexafluorobisphenol A disyanate, 2,2-bis (4-cyanate) phenylpropane, 1,1-bis (4-cyanate phenylmethane), bis (4-cyanate-3,5-) Bifunctional cyanate resins such as dimethylphenyl) methane, 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, and bis (4-cyanatephenyl) ether, Examples thereof include polyfunctional cyanate resins derived from phenol novolak and cresol novolak, and prepolymers in which these cyanate resins are partially triazined. Specific examples of the cyanate ester-based curing agent include "PT30" and "PT60" (both are phenol novolac type polyfunctional cyanate ester resins), "BA230", and "BA230S75" (part of bisphenol A dicyanate) manufactured by Lonza Japan. Alternatively, a prepolymer in which the whole is triazined to become a trimer) and the like can be mentioned.

Thiol-based curing agents are curing agents having two or more mercapto groups, and are, for example, trimethylolpropanetris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptobutyrate), and tris (3-mercapto). Propyl) isocyanurate and the like.

The reaction group equivalent of the curing agent is preferably 50 g / eq. ~ 3000 g / eq. , More preferably 100 g / eq. ~ 1000 g / eq. , More preferably 100 g / eq. ~ 500 g / eq. , Particularly preferably 100 g / eq. ~ 300 g / eq. Is. The reaction group equivalent is the mass of the curing agent per reaction group equivalent. The reactive group is, for example, a phenolic hydroxyl group in the case of a phenolic curing agent. In the case of an acid anhydride-based curing agent, 1 equivalent of a carboxylic acid anhydride group (-CO-O-CO-) corresponds to 2 equivalents of a reactive group.

The content of the curing agent is preferably 30% by mass or less, more preferably 20% by mass or less, still more preferably, when the non-volatile component in the resin composition is 100% by mass, from the viewpoint of remarkably obtaining the effect of the present invention. Is 15% by mass or less, particularly preferably 10% by mass or less, for example, 0% by mass or more, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, still more preferable. Is 1% by mass or more, particularly preferably 3% by mass or more.

-Thermoplastic resin-
The resin composition may contain a thermoplastic resin. The thermoplastic resin may be used alone or in combination of two or more.

Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, acrylic resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamideimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polyetherimide resin, and polycarbonate resin. , Polyether ether ketone resin, polyester resin, and among them, a resin selected from a phenoxy resin, an acrylic resin and a polyphenylene ether resin is preferable.

Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetophenone skeleton, novolak skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantan skeleton, and terpene. Examples thereof include phenoxy resins having one or more skeletons selected from the group consisting of skeletons and trimethylcyclohexane skeletons. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. The phenoxy resin may be used alone or in combination of two or more. Specific examples of the phenoxy resin include "1256" and "4250" (both bisphenol A skeleton-containing phenoxy resin), "YX8100" (bisphenol S skeleton-containing phenoxy resin), and "YX6954" (bisphenol acetophenone) manufactured by Mitsubishi Chemical Corporation. (Skeletal-containing phenoxy resin), "FX280" and "FX293" manufactured by Nittetsu Chemical & Materials, "YX7200B35", "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30" manufactured by Mitsubishi Chemical Co., Ltd. , "YL6794", "YL7213", "YL7290", "YL7482" and the like.

Examples of the polyvinyl acetal resin include polyvinyl formal resin and polyvinyl butyral resin, and polyvinyl butyral resin is preferable. Specific examples of the polyvinyl acetal resin include, for example, "Electrified Butyral 4000-2", "Electrified Butyral 5000-A", "Electrified Butyral 6000-C", "Electrified Butyral 6000-EP", Sekisui Chemical Co., Ltd. Examples thereof include Eslek BH series, BX series (for example, BX-5Z), KS series (for example, KS-1), BL series, and BM series manufactured by Chemical Industry Co., Ltd.

The acrylic resin means a polymer obtained by polymerizing a monomer component containing a (meth) acrylic acid ester-based monomer. In addition to the (meth) acrylic acid ester-based monomer, the monomer component constituting the acrylic resin may contain a (meth) acrylamide-based monomer, a styrene-based monomer, a functional group-containing monomer and the like as a copolymerization component. Specific examples of the acrylic resin include "ARUFON UP-1000", "ARUFON UP-1010", "ARUFON UP-1020", "ARUFON UP-1021", "ARUFON UP-1061", and "ARUFON" manufactured by Toagosei Corporation. UP-1080, "ARUFON UP-1110", "ARUFON UP-1170", "ARUFON UP-1190", "ARUFON UP-1500", "ARUFON UH-2000", "ARUFON UH-2041", "ARUFON UH" -2190, "ARUFON UHE-2012", "ARUFON UC-3510", "ARUFON UG-4010", "ARUFON US-6100", "ARUFON US-6170" and the like. These may be used individually by 1 type, or may be used in combination of 2 or more types.

Examples of the polyolefin resin include ethylene-based copolymers such as low-density polyethylene, ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer. Polymerized resin; examples thereof include polyolefin-based elastomers such as polypropylene and ethylene-propylene block copolymers.

Examples of the polybutadiene resin include hydride polybutadiene skeleton-containing resin, hydroxy group-containing polybutadiene resin, phenolic hydroxyl group-containing polybutadiene resin, carboxy group-containing polybutadiene resin, acid anhydride group-containing polybutadiene resin, epoxy group-containing polybutadiene resin, and isocyanate group-containing. Examples thereof include polybutadiene resin, urethane group-containing polybutadiene resin, and polyphenylene ether-polybutadiene resin.

Specific examples of the polyimide resin include "Ricacoat SN20" and "Ricacoat PN20" manufactured by NEW JAPAN CHEMICAL CO., LTD. Specific examples of the polyimide resin include a linear polyimide obtained by reacting a bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (polyimide described in JP-A-2006-37083), and a polysiloxane skeleton. Examples thereof include modified polyimides such as contained polyimides (polyimides described in JP-A-2002-12667 and JP-A-2000-31386).

Specific examples of the polyamide-imide resin include "Vilomax HR11NN" and "Vilomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of the polyamide-imide resin include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imide) manufactured by Hitachi Chemical Industries, Ltd.

Specific examples of the polyether sulfone resin include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

Specific examples of the polysulfone resin include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

Specific examples of the polyphenylene ether resin include oligophenylene ether / styrene resin "OPE-2St1200" and "OPE-2St2200" manufactured by Mitsubishi Gas Chemical Company, Inc., and "Noryl (registered trademark) SA90" manufactured by SABIC. Specific examples of the polyetherimide resin include "Ultem" manufactured by GE.

Examples of the polycarbonate resin include a hydroxy group-containing carbonate resin, a phenolic hydroxyl group-containing carbonate resin, a carboxy group-containing carbonate resin, an acid anhydride group-containing carbonate resin, an isocyanate group-containing carbonate resin, and a urethane group-containing carbonate resin. Specific examples of the polycarbonate resin include "FPC0220" manufactured by Mitsubishi Gas Chemical Company, "T6002" and "T6001" (polycarbonate diol) manufactured by Asahi Kasei Chemicals, and "C-1090" and "C-2090" manufactured by Kuraray. , "C-3090" (polycarbonate diol) and the like. Specific examples of the polyetheretherketone resin include "Sumiproi K" manufactured by Sumitomo Chemical Co., Ltd. Examples of the polyester resin include polyethylene terephthalate resin and the like.

The weight average molecular weight of the thermoplastic resin is preferably 8,000 or more, more preferably 10,000 or more, still more preferably 20,000 or more, preferably 100,000 or less, more preferably 70,000 or less, and further. It is preferably 60,000 or less. The weight average molecular weight of the resin can be measured as a polystyrene-equivalent value by a gel permeation chromatography (GPC) method.

The thermoplastic resin is preferably a thermoplastic resin having a transmittance of 80% or more of light having a wavelength of 450 nm incident on the film surface in a direction perpendicular to the film surface when the film is formed to a thickness of 20 μm.

The content of the thermoplastic resin is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and particularly preferably 25, when the non-volatile component in the resin composition is 100% by mass. It is 0% by mass or more, for example, 0% by mass or more, 0.1% by mass or more, preferably 1% by mass or more, more preferably 5% by mass or more, and particularly preferably 10% by mass or more.

-Curing accelerator-
The resin composition may contain a curing accelerator. The curing accelerator has a function of accelerating the curing reaction of the thermosetting resin. The curing accelerator may be used alone or in combination of two or more.

Examples of the curing accelerator include phosphorus-based curing accelerators, imidazole-based curing accelerators, amine-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, and the like. Among them, as the curing accelerator, a phosphorus-based curing accelerator and an imidazole-based curing accelerator are preferable, and a phosphorus-based curing accelerator is more preferable, from the viewpoint of achieving a higher light reflectance.

The phosphorus-based curing accelerator preferably contains one or more selected from the group consisting of phosphonium salts and phosphines from the viewpoint of achieving higher light reflectance.

Examples of the phosphonium salt include tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis (tetrabutylphosphonium) pyromeritate, and tetrabutylphosphonium hydroxyhexahydro. Fat group phosphonium salts such as phthalate, tetrabutylphosphonium 2,6-bis [(2-hydroxy-5-methylphenyl) methyl] -4-methylphenorate, di-tert-butylmethylphosphonium tetraphenylborate; methyltriphenyl Phenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-triltriphenylphosphonium tetra-p-trilborate, tetraphenylphosphonium tetraphenyl Borate, Tetraphenylphosphonium Tetra p-Tolylborate, Triphenylethylphosphonium Tetraphenyl Borate, Tris (3-Methylphenyl) Ethylphosphonium Tetraphenyl Borate, Tris (2-methoxyphenyl) Ethylphosphonium Tetraphenyl Borate, (4-Methylphenyl) ) Aromatic phosphonium salts such as triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate and the like can be mentioned.

Examples of phosphine include tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl (2-butenyl) phosphine, di-tert-butyl (3-methyl-2-butenyl) phosphine, and tricyclohexyl. Aliphatic phosphines such as phosphine; dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m- Trilylphosphine, tri-p-trilphosphine, tris (4-ethylphenyl) phosphine, tris (4-propylphenyl) phosphine, tris (4-isopropylphenyl) phosphine, tris (4-butylphenyl) phosphine, tris (4-butylphenyl) tert-butylphenyl) phosphine, tris (2,4-dimethylphenyl) phosphine, tris (2,5-dimethylphenyl) phosphine, tris (2,6-dimethylphenyl) phosphine, tris (3,5-dimethylphenyl) phosphine , Tris (2,4,6-trimethylphenyl) phosphine, tris (2,6-dimethyl-4-ethoxyphenyl) phosphine, tris (2-methoxyphenyl) phosphine, tris (4-methoxyphenyl) phosphine, tris (4) -Ethoxyphenyl) phosphine, tris (4-tert-butoxyphenyl) phosphine, diphenyl-2-pyridylphosphine, 1,2-bis (diphenylphosphine) ethane, 1,3-bis (diphenylphosphine) propane, 1, Aromatic phosphines such as 4-bis (diphenylphosphine) butane, 1,2-bis (diphenylphosphine) acetylene, 2,2'-bis (diphenylphosphine) diphenyl ether; fragrances such as triphenylphosphine and triphenylborane. Group phosphine-boran complex; aromatic phosphine / quinone addition reaction product such as triphenylphosphine / p-benzoquinone addition reaction product and the like can be mentioned.

As the phosphorus-based curing accelerator, a commercially available product may be used, and examples thereof include "TBP-DA" manufactured by Hokuko Chemical Industry Co., Ltd.

Examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, and the like. 2-Ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-Cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- 2-Phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecyl Imidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino-6- [2'-ethyl-4'-methylimidazolyl- (1')]-ethyl-s-triazine, 2,4- Diamino-6- [2'-methylimidazolyl- (1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2- Phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline Examples thereof include imidazole compounds such as 2-phenylimidazolin and adducts of the imidazole compound and an epoxy resin, and 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole are preferable.

As the imidazole-based curing accelerator, a commercially available product may be used, and examples thereof include "P200-H50" manufactured by Mitsubishi Chemical Corporation and "1B2PZ-10M" manufactured by Shikoku Kasei Co., Ltd.

Examples of the amine-based curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6, -tris (dimethylaminomethyl) phenol, and 1,8-diazabicyclo. Examples thereof include (5,4,0) -undecene, and 4-dimethylaminopyridine and 1,8-diazabicyclo (5,4,0) -undecene are preferable.

Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine, and trimethylguanidine. Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo [4.4.0] deca-5-ene, 7-methyl-1,5,7-triazabicyclo [4.4.0] Deca-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylviguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1 -Allylbiguanide, 1-phenylbiguanide, 1- (o-tolyl) biguanide and the like can be mentioned, with dicyandiamide and 1,5,7-triazabicyclo [4.4.0] deca-5-ene being preferred.

Examples of the metal-based curing accelerator include organic metal complexes or organic metal salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of the organic metal complex include an organic cobalt complex such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, an organic copper complex such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. Examples thereof include organic zinc complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, zinc stearate and the like.

The content of the curing accelerator is preferably 5% by mass or less, more preferably 3% by mass or less, and further, when the non-volatile component in the resin composition is 100% by mass, from the viewpoint of remarkably obtaining the effect of the present invention. It is preferably 1% by mass or less, particularly preferably 0.8% by mass or less, for example, 0% by mass or more, 0.001% by mass or more, preferably 0.01% by mass or more, and more preferably 0.05. By mass or more, particularly preferably 0.1% by mass or more.

-Other additives-
The resin composition may further contain other additives as a non-volatile component. Examples of other additives include (meth) acrylic resins, photocurable components such as radically polymerizable compounds, diluents as auxiliaries thereof, photopolymerization initiators and the like; organic fillers such as rubber particles; silicone-based Leveling agents such as leveling agents and acrylic polymer leveling agents; thickeners such as Benton and montmorillonite; defoaming agents such as silicone-based defoaming agents, acrylic defoaming agents, fluorine-based defoaming agents and vinyl resin-based defoaming agents. Agents; UV absorbers such as benzophenone-based UV absorbers, benzotriazole-based UV absorbers, salicylic acid-based UV absorbers; Adhesive improvers such as ureasilane; Triazole-based adhesion-imparting agents, tetrazole-based adhesion-imparting agents, triazine Adhesion-imparting agents such as system-adhesion-imparting agents; Antioxidants such as hindered phenol-based antioxidants; Fluorescent whitening agents such as stilben derivatives; Surfactants such as fluorine-based surfactants and silicone-based surfactants ; Phosphorus flame retardant (eg phosphoric acid ester compound, phosphazene compound, phosphinic acid compound, red phosphorus), nitrogen flame retardant (eg melamine sulfate), halogen flame retardant, inorganic flame retardant (eg antimony trioxide), etc. Flame retardant; Dispersants such as phosphate ester dispersants, polyoxyalkylene dispersants, acetylene dispersants, silicone dispersants, anionic dispersants, cationic dispersants; borate stabilizers, titanate stabilizers , Aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, carboxylic acid anhydride-based stabilizers and the like. As the other additives, one type may be used alone, or two or more types may be used in combination at any ratio. The content of other additives can be appropriately set by those skilled in the art.

-Organic solvent-
The resin composition may further contain an arbitrary organic solvent as a volatile component in addition to the above-mentioned non-volatile component. As the organic solvent, known ones can be appropriately used, and the type thereof is not particularly limited. Examples of the organic solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone and the like. Ester-based solvent; Ether-based solvent such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether; Alcohol-based solvent such as methanol, ethanol, propanol, butanol, ethylene glycol; 2-Acetic acid Ether ester solvents such as ethoxyethyl, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, methyl methoxypropionate; esters such as methyl lactate, ethyl lactate, methyl 2-hydroxyisobutyrate, etc. Alcohol-based solvent; ether alcohol-based solvent such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, diethylene glycol monobutyl ether (butyl carbitol); N, N-dimethylformamide, N, N- Amido-based solvents such as dimethylacetamide and N-methyl-2-pyrrolidone; Sulfoxide-based solvents such as dimethylsulfoxide; Nitrile-based solvents such as acetonitrile and propionitrile; aliphatic hydrocarbons such as hexane, cyclopentane, cyclohexane and methylcyclohexane System solvent: Aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene can be mentioned. The organic solvent may be used alone or in combination of two or more at any ratio.

The content of the organic solvent is not particularly limited, but when all the components in the resin composition are 100% by mass, for example, 65% by mass or less, 60% by mass or less, 45% by mass or less, 40% by mass. % Or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, 5% by mass or less, and the like.

The resin composition can be, for example, a white inorganic pigment, a thermosetting resin, and, if necessary, other inorganic fillers, curing agents, thermoplastic resins, curing accelerators, and other additives in any preparation container. It can be produced by adding and mixing organic solvents in any order and / or partially or all at the same time. Further, in the process of adding and mixing each component, the temperature can be appropriately set, and heating and / or cooling may be performed temporarily or from beginning to end. Further, the resin composition may be uniformly dispersed by stirring or shaking using, for example, a stirring device such as a mixer or a shaking device in the process of adding and mixing, or thereafter. Further, at the same time as stirring or shaking, defoaming may be performed under low pressure conditions such as under vacuum.

The resin composition used for forming the cured product of the present invention is from the viewpoint that the cured product can be easily and efficiently provided on the base substrate, and the ratio of the component areas of the inorganic filler (A _0-5 /). From the viewpoint that it is easy to realize a cured product in which A _5-10 ) is in a specific range, it is preferable to use it in the form of a resin sheet containing a layer of the resin composition.

<Resin sheet>
In one embodiment, the resin sheet includes a support and a layer of the resin composition provided on the support (hereinafter, simply referred to as "resin composition layer").

Examples of the support include a film made of a plastic material, a metal foil, and a release paper, and a film made of a plastic material and a metal foil are preferable.

When a film made of a plastic material is used as the support, the plastic material includes, for example, polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), and acrylic such as polycarbonate (PC) and polymethylmethacrylate (PMMA). , Cyclic polyolefin, Triacetyl Cellulose (TAC), Polyether Sulfide (PES), Polyether Ketone, Polyimide and the like. Of these, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable.

When a metal foil is used as the support, examples of the metal foil include copper foil, aluminum foil, and the like, and copper foil is preferable. As the copper foil, a foil made of a single metal of copper may be used, and a foil made of an alloy of copper and another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used. You may use it.

The support may be matted, corona-treated, or antistatic-treated on the surface to be joined to the resin composition layer.

Further, as the support, a support with a release layer having a release layer on the surface to be joined to the resin composition layer may be used. Examples of the release agent used for the release layer of the support with the release layer include one or more release agents selected from the group consisting of alkyd resin, polyolefin resin, urethane resin, and silicone resin. .. As the support with a release layer, a commercially available product may be used. For example, "PET501010" and "SK-" manufactured by Lintec Corporation, which are PET films having a release layer containing an alkyd resin-based mold release agent as a main component. 1 ”,“ AL-5 ”,“ AL-7 ”;“ Lumilar T60 ”manufactured by Toray Industries, Inc .;“ Purelex ”manufactured by Teijin Ltd.;“ Unipeel ”manufactured by Unitika Ltd.

The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. When a support with a release layer is used, the thickness of the entire support with a release layer is preferably in the above range.

From the viewpoint of facilitating the realization of a cured product in which the ratio of the component areas of the inorganic filler (A _0-5 / A _5-10 ) is in a specific range, the resin composition layer has a minimum melt viscosity of 5000 poise or less. It is preferable, more preferably 2000 poise or less, still more preferably 1000 poise or less, and particularly preferably 500 poise or less.

In one embodiment, the resin sheet may further contain other layers, if necessary. Examples of such other layers include a protective film similar to the support provided on the surface of the resin composition layer that is not bonded to the support (that is, the surface opposite to the support). Be done. The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, it is possible to suppress the adhesion and scratches of dust and the like on the surface of the resin composition layer.

For the resin sheet, for example, a resin varnish prepared by dissolving the resin composition as it is in a liquid resin composition or in an organic solvent is applied onto a support using a die coater or the like, and further dried. It can be produced by forming a resin composition layer.

Examples of the organic solvent include the same organic solvents as those described as the components of the resin composition. The organic solvent may be used alone or in combination of two or more.

Drying may be carried out by a known method such as heating or blowing hot air. The drying conditions are not particularly limited, but the resin composition layer is dried so that the content of the organic solvent is 10% by mass or less, preferably 5% by mass or less. Although it depends on the boiling point of the organic solvent in the resin composition (resin varnish), for example, when a resin composition (resin varnish) containing an organic solvent of 30% by mass to 60% by mass is used, the temperature is 50 ° C. to 150 ° C. for 3 minutes. The resin composition layer can be formed by drying for about 10 minutes.

The resin sheet can be rolled up and stored. If the resin sheet has a protective film, it can be used by peeling off the protective film.

The cured product of the present invention can be obtained by providing the above resin composition containing an inorganic filler component containing at least a white inorganic pigment on a base substrate and curing the resin composition. Preferably, the cured product of the present invention is obtained by laminating the resin sheet on the base substrate so that the base substrate and the resin composition layer are bonded to each other, and then curing the resin composition layer.

The substrate and the resin sheet may be laminated under the conditions of step (I) described later in relation to the method for manufacturing a printed wiring board. Further, the curing of the resin composition may be carried out under the conditions of step (II) described later in relation to the method for manufacturing a printed wiring board. From the viewpoint of facilitating the realization of a cured product in which the ratio of the component areas of the inorganic filler (A _0-5 / A _5-10 ) is in a specific range, preheating may be performed before the resin composition is cured, and the heating may be performed. It may be performed a plurality of times including preheating.

[Laminated structure]
The laminated structure of the present invention includes a substrate having a conductor layer on at least a part of the surface (“underlying substrate”), and a cured body of the present invention provided on the substrate.

The base substrate is not particularly limited as long as it has a conductor layer on at least a part of the surface, and is, for example, one side of a substrate such as a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, and a thermosetting polyphenylene ether substrate. Alternatively, a conductor layer formed on both sides thereof may be mentioned. Further, the conductor layer may be patterned. A substrate in which a conductor layer (circuit) is formed on one side or both sides of a substrate is sometimes referred to as an "inner layer circuit board". Further, an intermediate product in which an insulating layer and / or a conductor layer should be further formed when manufacturing a printed wiring board (light reflecting board) is also included in the "board" in the present invention. When the light reflection board is a circuit board with built-in components, a circuit board with built-in components may be used. The characteristics and composition of the cured product of the present invention provided on the base substrate are as described above.

The laminated structure of the present invention exhibits high light reflectance because it has a phase rich in the inorganic filler component in the region near the first main surface of the cured product. Further, the laminated structure of the present invention can achieve such a high light reflectance without a decrease in the adhesion strength between the base substrate and the cured body. The light reflectance and the adhesion strength are as described above.

[Reflective sheet, printed wiring board]
The reflective sheet of the present invention contains the cured product of the present invention. Further, the printed wiring board of the present invention includes the reflective sheet of the present invention. As an example shown in FIG. 1, in the printed wiring board 1, a reflective sheet 3 is formed on a substrate 2, and a light source 4 such as a light emitting diode (LED) is arranged on a surface 31 of the reflective sheet 3. There is. The substrate 2 corresponds to the above-mentioned "base substrate" (the conductor layer is not shown in FIG. 1), and the surface 31 of the reflective sheet 3 corresponds to the above-mentioned "first main surface".

Since the reflective sheet contains the cured product of the present invention, it exhibits high light reflectance and good substrate adhesion. The light reflectance and the adhesion strength are as described above.

The printed wiring board and the reflective sheet of the present invention can be produced, for example, by using the above-mentioned resin sheet by a method including the following steps (I), (II) and (III).
(I) A step of laminating the resin composition layer of the resin sheet on the substrate so as to be bonded to the substrate (II) A step of thermosetting the resin composition layer to form a reflective sheet (III) A light source on the reflective sheet Placement process

The substrate used in the step (I) is not particularly limited as long as the conductor layer is provided on at least a part of the surface, and as described above, for example, a circuit board having a conductor circuit on the surface can be used.

The substrate and the resin sheet can be laminated, for example, by heat-pressing the resin sheet to the substrate from the support side. Examples of the member for heat-crimping the resin sheet to the substrate (hereinafter, also referred to as “heat-crimping member”) include a heated metal plate (SUS end plate or the like) or a metal roll (SUS roll). It is preferable not to press the heat-bonded member directly onto the resin sheet, but to press it through an elastic material such as heat-resistant rubber so that the resin sheet sufficiently follows the surface irregularities of the substrate.

The substrate and the resin sheet may be laminated by a vacuum laminating method. In the vacuum laminating method, the heat crimping temperature is preferably in the range of 60 ° C. to 160 ° C., more preferably 80 ° C. to 140 ° C., and the heat crimping pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0. It is in the range of .29 MPa to 1.47 MPa, and the heat crimping time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions with a pressure of 26.7 hPa or less.

Lamination can be performed by a commercially available vacuum laminator. Examples of the commercially available vacuum laminator include a vacuum pressurizing laminator manufactured by Meiki Co., Ltd., a vacuum applicator manufactured by Nikko Materials, and a batch type vacuum pressurizing laminator.

After laminating, the laminated resin sheet may be smoothed by pressing under normal pressure (under atmospheric pressure), for example, from the support side. The press conditions for the smoothing treatment can be the same as the heat-bonding conditions for the above-mentioned lamination. The smoothing process can be performed by a commercially available laminator. The laminating and smoothing treatment may be continuously performed using the above-mentioned commercially available vacuum laminator.

The support may be removed between steps (I) and step (II) or after step (II). From the viewpoint of facilitating the realization of a cured product in which the ratio of the component areas of the inorganic filler (A _0-5 / A _5-10 ) is in a specific range, the support is removed between the steps (I) and the step (II). Is preferable.

In step (II), the resin composition layer is thermally cured to form a reflective sheet. For example, the thermosetting conditions of the resin composition layer differ depending on the type of the resin composition and the like, but the curing temperature is preferably 120 ° C to 240 ° C, more preferably 130 ° C to 220 ° C, still more preferably 150 ° C to 210. ℃. The curing time can be preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

Before curing the resin composition, the resin composition may be preheated at a temperature lower than the curing temperature. For example, prior to thermosetting the resin composition, the resin composition is heated at a temperature of 50 ° C. or higher and lower than 120 ° C. (preferably 60 ° C. or higher and 115 ° C. or lower, more preferably 70 ° C. or higher and 110 ° C. or lower) for 5 minutes. Preheating may be performed as described above (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, still more preferably 15 minutes to 100 minutes).

In order to increase the efficiency of extracting light emitted from the light source, the reflective sheet may have a concave portion on the surface of the reflective sheet on the light source side in addition to the planar shape as shown in FIG.

In step (III), the light source is placed on the reflective sheet. For example, when the surface of the reflective sheet has a recess, the light source is arranged in the recess.

If necessary, after electrically connecting the light source, the light source may be sealed or the like to fix the light source.

In the printed wiring board of the present invention, the reflective sheet may be included as an interlayer insulating layer or a solder resist. Therefore, in one embodiment, the printed wiring board of the present invention includes the reflective sheet of the present invention as an interlayer insulating layer or a solder resist.

[Semiconductor device]
The semiconductor device of the present invention includes the printed wiring board of the present invention. The semiconductor device of the present invention can be manufactured by mounting a component (semiconductor chip) on a conductive portion of a printed wiring board. For example, a semiconductor device equipped with a light emitting diode (LED) that emits light with low power, such as a backlight of a liquid crystal display such as a mobile terminal, a computer, or a television; or a light source of a lighting fixture.

Hereinafter, the present invention will be specifically described with reference to Examples. The present invention is not limited to these examples. In the following, "parts" and "%" representing quantities mean "parts by mass" and "% by mass", respectively, unless otherwise specified. When the temperature is not specified, the temperature and pressure conditions are room temperature (25 ° C.) and atmospheric pressure (1 atm).

<Example 1>
(1) Preparation of resin composition Liquid bisphenol A type epoxy resin (Mitsubishi Chemical Corporation "jER828EL", epoxy equivalent 180 g / eq.), 4 parts, solid fluorine atom-containing epoxy resin (Mitsubishi Chemical Corporation "YX7760", epoxy Equivalent 245 g / eq.) 4 parts, biphenyl skeleton and cyclohexane skeleton-containing phenoxy resin ((Mitsubishi Chemical Corporation "YX7200B35", weight average molecular weight 30,000, 20 μm film light transmittance (450 nm) 88%, solid content 35% by mass) 20 parts of MEK solution) was heated and dissolved in 8 parts of MEK while stirring. Titanium oxide (“PX3788” manufactured by Sakai Chemical Industry Co., Ltd., phenylsilane coupling agent (“KBM-103” manufactured by Shinetsu Chemical Industry Co., Ltd.)). Treated, average particle size 0.26 μm, specific surface area 13.2 m ² / g, reflectance 99% for light with a wavelength of 500 nm) 10 parts, spherical silica (“SO-C2” manufactured by Admatex, methacrylic silane coupling) Agent (Shinetsu Chemical Industry Co., Ltd. "KBM-503") treated, average particle size 0.5 μm, reflectance about 80% for light with a wavelength of 500 nm) 10 parts, bisphenol AF (Central Glass Co., Ltd. "BIS-AF" MEK Mix 4 parts of a solution adjusted to 50% non-volatile component and 0.2 part of a phosphorus-based curing accelerator (“TBP-DA” manufactured by Hokuko Kagaku Kogyo Co., Ltd.) and uniformly disperse with a high-speed rotary mixer to form a resin composition. A thing (wanice) was prepared.

(2) Preparation of resin sheet As a support, a PET film with a release layer (“PET501010” manufactured by Lintec Corporation, thickness 38 μm) was prepared. The resin composition prepared in (1) above was uniformly applied onto the release layer of the support so that the thickness of the dried resin composition layer was 50 μm. Then, the resin composition was heated at 80 ° C. for 4 minutes to obtain a resin sheet containing a resin composition layer having a thickness of 50 μm.

(3) Manufacture of cured product (i) Substrate treatment of circuit board Glass cloth base material Epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.8 mm, “R5715ES” manufactured by Matsushita Electric Industrial Co., Ltd.) A circuit pattern was formed on both sides of the surface by etching to prepare an inner layer circuit board having an in-plane copper area of 30%. The copper circuit of the obtained inner layer circuit board was roughened with a micro-etching agent (“CZ8100” manufactured by MEC).

(Ii) Laminating of resin sheet The resin sheet prepared in (2) above is bonded to the inner layer circuit board by using a batch type vacuum pressurizing laminator (“MVLP-500” manufactured by Meiki Co., Ltd.). It was laminated on both sides of the base-treated inner layer circuit board so as to be used. Lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less, and then crimping at 120 ° C. for 30 seconds at a pressure of 0.74 MPa.

(Iii) Thermal curing of the resin composition layer After the support was peeled off, the resin composition layer was cured by heating at 180 ° C. for 90 minutes. As a result, a laminated structure including a circuit board and a cured product provided on the circuit board was obtained.

<Example 2>
Liquid bisphenol A type epoxy resin (Mitsubishi Chemical "jER828EL", epoxy equivalent 180 g / eq.) 4 parts and solid fluorine atom-containing epoxy resin (Mitsubishi Chemical "YX7760", epoxy equivalent 245 g / eq.) 4 parts Instead, 4 parts of hydrogenated liquid epoxy resin (Mitsubishi Chemical "YX8000", epoxy equivalent 205 g / eq.) And 4 parts of biphenyl type epoxy resin (Mitsubishi Chemical "YX4000H", epoxy equivalent 195 g / eq.) In the same manner as in Example 1, a resin composition and a resin sheet were prepared, and a cured product and a laminated structure were produced.

<Example 3>
(1) The amount of titanium oxide ("PX3788" manufactured by Sakai Chemical Industry Co., Ltd., treated with phenylsilane coupling agent) was changed from 10 parts to 20 parts, and (2) spherical silica ("SO" manufactured by Admatex Co., Ltd.). A resin composition and a resin sheet were prepared in the same manner as in Example 1 except that "-C2" (treated with a methacrylicsilane coupling agent) was not blended, and a cured product and a laminated structure were produced.

<Example 4>
A resin composition and a resin sheet were prepared in the same manner as in Example 1 except that bisphenol AF (a solution prepared by adjusting "BIS-AF" manufactured by Central Glass Co., Ltd. to a non-volatile content of 50% with MEK) was not blended. A cured body and a laminated structure were manufactured.

<Example 5>
Instead of 20 parts of a phenoxy resin containing a biphenyl skeleton and a cyclohexane skeleton ("YX7200B35" manufactured by Mitsubishi Chemical Co., Ltd., a MEK solution having a weight average molecular weight of 30,000 and a solid content of 35% by mass), a non-functional acrylic resin (manufactured by Toagosei Co., Ltd. " ARUFON UP-1020 ”, weight average molecular weight 2,000) 7 parts) were used, but a resin composition and a resin sheet were prepared in the same manner as in Example 1 to produce a cured product and a laminated structure.

<Example 6>
Instead of 20 parts of a phenoxy resin containing a biphenyl skeleton and a cyclohexane skeleton ("YX7200B35" manufactured by Mitsubishi Chemical Co., Ltd., a MEK solution having a weight average molecular weight of 30,000 and a solid content of 35% by mass), a low molecular weight polyphenylene ether resin ("Noryl" manufactured by SABIC Co., Ltd.) A resin composition and a resin sheet were prepared in the same manner as in Example 1 except that 7 parts (SA90”, molecular weight 1700, 20 μm film light transmittance (450 nm) 85%) were used, and a cured product and a laminated structure were prepared. Manufactured.

<Comparative Example 1>
(1) The amount of titanium oxide ("PX3788" manufactured by Sakai Chemical Industry Co., Ltd., treated with phenylsilane coupling agent) was changed from 10 parts to 4 parts, and (2) spherical silica ("SO" manufactured by Admatex Co., Ltd.). A resin composition and a resin sheet were prepared in the same manner as in Example 1 except that the blending amount of "-C2" (treated with a methacrylicsilane coupling agent) was changed from 10 parts to 18 parts, and the cured product and laminated body were prepared. The structure was manufactured.

<Comparative Example 2>
(1) The amount of titanium oxide ("PX3788" manufactured by Sakai Chemical Industry Co., Ltd., treated with phenylsilane coupling agent) was changed from 10 parts to 40 parts, and (2) spherical silica ("SO" manufactured by Admatex Co., Ltd.). A resin composition and a resin sheet were prepared in the same manner as in Example 1 except that "-C2" (treated with a methacrylicsilane coupling agent) was not blended, and a cured product and a laminated structure were produced.

<Comparative Example 3>
(1) Preparation of resin composition Biphenyl type epoxy resin (Nippon Kayaku Co., Ltd. "NC3000H", epoxy equivalent about 272 g / eq.), 3 parts, tetrakis hydroxyphenyl ethane type epoxy resin (Mitsubishi Chemical Co., Ltd. "jER1031S", epoxy Equivalent about 200 g / eq.) 2 parts, bisphenol A type epoxy acrylate (Nippon Kayaku Co., Ltd. "ZAR-2000", acid value 99 mgKOH / g, non-volatile component 70%) 10 parts, diluent (Nippon Kayaku Co., Ltd. "ZAR-2000" DPHA ”, dipentaerythritol hexaacrylate, acrylic equivalent of about 96 g / eq.) Was dissolved by heating in 6 parts of MEK and 10 parts of ethyl diglycol acetate with stirring. There, titanium oxide (“PX3788” manufactured by Sakai Chemical Industry Co., Ltd., phenylsilane coupling agent (“KBM-103” manufactured by Shinetsu Chemical Industry Co., Ltd.)) has been treated, the average particle size is 0.26 μm, and the specific surface area is 13.2 m ² / g. 4 parts of spherical silica (admatex "SO-C2", methacrylicsilane coupling agent (Shinetsu Chemical Industry Co., Ltd. "KBM-503" treated), average particle size 0.5 μm) , 4 parts of photopolymerization initiator (BASF "Irgacure819", bis (2,4,6-trimethylbenzoyl) -phenylphosphin oxide) 0.04 part. Then, it was uniformly dispersed with a high-speed rotary mixer to prepare a resin composition.

(2) Preparation of Resin Sheet Using the resin composition prepared in (1) above, a resin sheet was prepared in the same manner as in Example 1. The prepared resin sheet includes a support and a photosensitive resin composition layer provided on the support.

(3) Production of cured product In the same manner as in Example 1, (i) the substrate treatment of the circuit board and (ii) the laminating of the resin sheet were carried out. Then, after the support was peeled off, the photosensitive resin composition layer was exposed to ultraviolet rays of 100 mJ / cm ² and photo-cured. Then, a 1% by mass sodium carbonate aqueous solution at 30 ° C. was spray-developed on the entire surface of the photosensitive resin composition layer at a spray pressure of 0.2 MPa for 2 minutes. After spray development, ultraviolet irradiation of 1 J / cm ² was performed, and the mixture was further heated at 190 ° C. for 90 minutes to cure the photosensitive resin composition layer. As a result, a laminated structure including a circuit board and a cured product provided on the circuit board was obtained.

Hereinafter, various measurement methods and evaluation methods will be described.

<Measurement of area ratio of inorganic filler components>
(1) Preparation of cross-section sample The laminated structures produced in Examples and Comparative Examples were cross-sectioned so that the cross-section in the direction perpendicular to the first main surface of the cured product was exposed, and a cross-section sample was prepared. A focused ion beam (FIB) attached to a scanning electron microscope was used for cross-sectioning.

(2) Calculation of component area ratio of inorganic filler A cross-sectional sample was observed using a scanning electron microscope (focused ion beam / scanning ion microscope "SMI3050SE" manufactured by SI Nanotechnology Co., Ltd.) and perpendicular to the first main surface. An SEM image relating to the cross section of the cured product in the above direction was obtained. With respect to the obtained SEM image, the inorganic filler component area _Ad1-d2 in the region where the distance from the first main surface of the cured product is from d1 (μm) to d2 (μm) and the area from the first main surface. The inorganic filler component area A _d2-d3 in the region where the distance was from d2 (μm) to d3 (μm) was measured. Then, the inorganic filler component area ratio (kA _d1-d2 / A _d2-d3 ) was calculated from the obtained _Ad1-d2 value and _Ad2-d3 value.
Specifically, the obtained SEM image is saved as an image, and the resin component portion is blackened using image analysis software (“ImageJ” manufactured by the National Institutes of Health), and the inorganic filler component portion other than the resin component is used. Was converted into black and white and binarized, and the area _Ad1-d2 value and _Ad2-d3 value of the inorganic filler component were derived as the number of pixels in the white portion for each region. In calculating the ratio A _0-5 / A _5-10 of the component area of the inorganic filler, d1 = 0 (μm), d2 = 5 (μm), d3 = 10 (μm), k = 1, and the measurement area. The width of was 7.5 μm. The measurement was carried out at 10 points, and the obtained average value was taken as the ratio of the inorganic filler component area A _0-5 / A _5-10 .
When measuring the area ratio of the inorganic filler component, the value of (number of pixels of the inorganic filler component portion) / (total number of pixels of the cross section of the cross-sectional sample) × 100 is the volume% of the inorganic filler component of the cross-sectional sample. The binarization threshold was set so that the value was in the range of ± 3, and the conditions were calibrated.

<Measurement of light reflectance>
The laminated structure manufactured in Examples and Comparative Examples was cut into a width of 50 mm and a length of 50 mm, and the reflectance (%) with respect to light having a wavelength of 460 nm was measured with a multi-channel spectroscope (MCPD-7700, manufactured by Otsuka Electronics Co., Ltd.). However, it was evaluated according to the following criteria.

Evaluation criteria for light reflectance:
⊚: Reflectance is 95% or more ○: Reflectance is 90% or more and less than 95% Δ: Reflectance is 80% or more and less than 90% ×: Reflectance is less than 80%

<Measurement of substrate adhesion>
(1) Base treatment of copper foil The glossy surface of electrolytic copper foil (“3EC-III” manufactured by Mitsui Mining & Smelting Co., Ltd., thickness 35 μm) is immersed in a micro-etching agent (Mech Etch Bond “CZ-8101” manufactured by Mech Co., Ltd.). Then, the copper surface was roughened (Ra value = 1 μm) and rust-proofed (CL8300). Then, it was heat-treated in an oven at 130 ° C. for 30 minutes. The obtained copper foil is hereinafter referred to as CZ copper foil.

(2) Laminating of Resin Sheets The resin sheets prepared in Examples and Comparative Examples were laminated on CZ copper foil to prepare a resin sheet with copper foil. The laminating conditions were the same as the laminating conditions in "(3) Production of cured product" of Example 1.

(3) Curing of Resin Composition Using the resin sheet with copper foil produced in (2) above, the thermosetting conditions in "(3) Production of cured product" of Example 1 or "(3) of Comparative Example 3" A cured product with a copper foil was obtained by curing under the same conditions as the photo-curing / thermosetting conditions in "Manufacturing a cured product". Specifically, for the resin sheet with copper foil produced by using the resin sheets prepared in Examples 1 to 6 and Comparative Examples 1 and 2, the same thermosetting conditions as in Example 1 were applied to the resin sheet prepared in Comparative Example 3. The same photocuring / thermosetting conditions as in Comparative Example 3 were applied to the resin sheet with a copper foil prepared using the above.

(4) Fixing to the circuit board The cured body with copper foil obtained in (3) above is adhered to both sides of the circuit board that has been grounded so that the cured body is in contact with the circuit board, using an adhesive (Aron Alpha EX). did. The ground-treated circuit board was the same as that prepared in "(3) Production of cured product" of Example 1.
Next, the cured product with copper foil and the circuit board were laminated under the same conditions as the laminating conditions in "(3) Production of the cured product" of Example 1. As a result, an evaluation sample having a layer structure of CZ copper foil / cured body / circuit board / cured body / CZ copper foil was obtained.

(5) Measurement of substrate adhesion (adhesion strength) The evaluation sample obtained in (4) above was cut into small pieces of 150 × 30 mm. Use a cutter to make a notch in the copper foil part of a small piece with a width of 10 mm and a length of 100 mm, peel off one end of the copper foil, and use a gripper (TSE Autocom type testing machine "AC-". 50C-SL ”), and using an Instron universal tester, measure the load when the 35 mm is peeled off vertically at a speed of 50 mm / min at room temperature in accordance with JIS C6481. Evaluated according to the criteria of.

Evaluation criteria for substrate adhesion:
⊚: Adhesion strength is 0.5 kgf / cm or more 〇: Adhesion strength is 0.4 kgf / cm or more and less than 0.5 kgf / cm Δ: Adhesion strength is 0.3 kgf / cm or more and less than 0.4 kgf / cm ×: Adhesion Strength is less than 0.3kgf / cm

Table 1 shows the amount of non-volatile components used in the cured products produced in Examples and Comparative Examples, and the measurement results and evaluation results.

1 Printed wiring board 2 Board 3 Reflective sheet 31 Reflective sheet surface 4 Light source

Claims (14)

A cured product of a resin composition containing an inorganic filler component containing at least a white inorganic pigment, which is provided on a substrate having a conductor layer on at least a part of the surface thereof.
When the non-volatile component in the cured product is 100% by mass, the content of the white inorganic pigment is 20% by mass or more.
When the surface of the cured product on the side not in contact with the substrate is used as the first main surface,
Area A of the inorganic filler component per unit area in the region where the distance from the first main surface of the cured body is from 0 μm to 5 μm in the cross section of the cured body in the direction perpendicular to the first main surface of the cured body. _0-5 and the area A _5-10 of the inorganic filler component per unit area in the region where the distance from the first main surface is from 5 μm to 10 μm are A _0-5 / A _5-10 > 1. A cured product that satisfies 1. The cured product according to claim 1, further comprising a thermosetting resin. The cured product according to claim 1 or 2, wherein the content of the white inorganic pigment is 20 to 60% by mass when the non-volatile component in the cured product is 100% by mass. The cured product according to claim 2 or 3, wherein the thermosetting resin contains an epoxy resin. The cured product according to claim 4, wherein the content of the epoxy resin is 10 to 50% by mass when the non-volatile component in the cured product is 100% by mass. The white inorganic pigment is at least one selected from aluminum oxide, titanium oxide, zirconium oxide, magnesium oxide, barium titanate, zinc oxide, cerium oxide, and calcium carbonate, according to any one of claims 1 to 5. The cured product described. The cured product according to any one of claims 1 to 6, which is used for an insulating layer of a printed wiring board or a solder resist layer. The cured product according to any one of claims 1 to 7, which is for light reflection. The cured product according to any one of claims 1 to 8, which has a reflectance of 80% or more with respect to light having a wavelength of 460 nm. A laminated structure including a substrate having a conductor layer on at least a part of the surface thereof and a cured product according to any one of claims 1 to 9 provided on the substrate. A reflective sheet containing the cured product according to any one of claims 1 to 9. A printed wiring board comprising the reflective sheet according to claim 11 as an interlayer insulating layer or a solder resist. A printed wiring board containing the cured product according to any one of claims 1 to 9. A semiconductor device comprising the printed wiring board according to claim 12 or 13.

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