Resin particles and circuit board with insulating layer

Abstract

The present invention provides resin particles capable of exhibiting low dielectricity while exhibiting low thermal expansion properties. The resin particles according to the present invention comprise a resin particle main body and a plurality of silica particles, the plurality of silica particles being present on the surface or inside of the resin particle main body, the resin particle main body being a polymer of a polymerizable component, and the polymerizable component comprising a polymerizable compound having one or more maleimide groups.

Description

Technical Field

[0001] The present invention relates to resin particles of polymers comprising polymeric compounds having one or more maleimide groups, and circuit boards with insulating layers using the resin particles. Background Technology

[0002] Bismaleimide resins are known to be resins with low dielectric properties.

[0003] Resin particles using bismaleimide resin are known. Patent Document 1 below discloses polybismaleimide crosslinked particles having specific repeating structural units. The above-mentioned polybismaleimide crosslinked particles are obtained by polymerization of a monomer having two maleimide groups individually or together with other monomers that can copolymerize with it by dispersion polymerization.

[0004] Patent Document 1 discloses that the particle size of the aforementioned polybismaleimide crosslinked particles can be set to 10 nm to 10 μm; and that the aforementioned polybismaleimide crosslinked particles exhibit excellent monodispersity. Furthermore, Patent Document 1 discloses that the aforementioned polybismaleimide crosslinked particles can be used in resin compositions requiring high heat resistance, high insulation, and low dielectric properties.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2012-193325 Summary of the Invention

[0008] The problem the invention aims to solve

[0009] For resin particles using bismaleimide resin as described in Patent Document 1, there is a problem of poor thermal expansion (low dimensional stability).

[0010] Existing resin particles are difficult to achieve both low thermal expansion and low dielectric properties.

[0011] The object of the present invention is to provide resin particles that exhibit low thermal expansion and low dielectric properties, and a circuit board with an insulating layer using the resin particles.

[0012] Problem Solving Methods

[0013] This specification discloses the following resin particles and circuit boards with insulating layers.

[0014] Item 1. A resin particle comprising a resin particle body and a plurality of silica particles, wherein the plurality of silica particles are present on the surface or inside the resin particle body, wherein the resin particle body is a polymer of a polymeric component, wherein the polymeric component comprises a polymeric compound having one or more maleimide groups.

[0015] Item 2. The resin particles according to Item 1, wherein the particle size of the resin particles is 0.5 μm or more.

[0016] Item 3. The resin particles according to item 1 or 2, wherein the particle size of the silica particles is less than 1.0 μm.

[0017] Item 4. The resin particles according to any one of items 1 to 3, wherein the ratio of the particle size of the silica particles to the particle size of the resin particles is 0.001 or more and 0.5 or less.

[0018] Item 5. The resin particles according to any one of items 1 to 4, wherein, in 100% by weight of the resin particles, the content of the silica particles is 0.1% by weight or more and 20% by weight or less.

[0019] Item 6. The resin particles according to any one of items 1 to 5, wherein, in 100% by weight of the polymeric component, the content of the polymeric compound having one or more maleimide groups is 10% by weight or more.

[0020] Item 7. The resin particles according to any one of items 1 to 6, wherein the polymerizable component comprises a crosslinking monomer different from the polymerizable compound having one or more maleimide groups.

[0021] Item 8. The resin particles according to Item 7, wherein the crosslinking monomer is divinylbenzene or a polymeric compound having two or more (meth)acryloyl groups.

[0022] Item 9. The resin particles according to Item 7 or 8, wherein, in 100% by weight of the polymerizable component, the content of the crosslinking monomer is 10% by weight or more.

[0023] Item 10. The resin particles according to any one of items 1 to 9, wherein the coefficient of thermal expansion of the resin particles at 50°C to 150°C is less than 150 ppm / °C.

[0024] Item 11. The resin particles according to any one of items 1 to 10, wherein the dielectric constant of the resin particles is 2.80 F / m or less, and the dielectric loss tangent of the resin particles is 0.01 or less.

[0025] Item 12. The resin particle according to any one of items 1 to 11, wherein, in at least one of the plurality of the aforementioned silica particles, a portion of the silica particles is present inside the resin particle body and a portion of the silica particles is present on the surface of the resin particle body.

[0026] Item 13. A circuit board with an insulating layer, comprising a circuit board and an insulating layer disposed on the surface of the circuit board, wherein the insulating layer comprises resin particles as described in any one of items 1 to 12.

[0027] The effects of the invention

[0028] The resin particles of the present invention comprise a resin particle body and a plurality of silica particles, wherein the plurality of silica particles are present on the surface or inside the resin particle body, and the resin particle body is a polymer of a polymeric component, wherein the polymeric component comprises a polymeric compound having one or more maleimide groups. Because of the above-described structure, the resin particles of the present invention are able to exhibit both low thermal expansion and low dielectric properties. Attached Figure Description

[0029] Figure 1 This is a schematic cross-sectional view illustrating resin particles according to the first embodiment of the present invention.

[0030] Figure 2 This is a schematic cross-sectional view illustrating resin particles according to the second embodiment of the present invention.

[0031] Figure 3 This is a schematic cross-sectional view of a multilayer printed circuit board using resin particles according to the first embodiment of the present invention.

[0032] Figure 4 It is a schematic cross-sectional view used to illustrate the location of silica particles contained in resin particles.

[0033] Symbol Explanation

[0034] 1, 1A··· Resin particles

[0035] 2··· Resin Particle Main Body

[0036] 3, 3A···Silica particles

[0037] 11. Multilayer printed circuit board (circuit board with insulating layer)

[0038] 12···Circuit Board

[0039] 12a··· Upper surface

[0040] 13~16··· Insulation layer

[0041] 17···Metal Layer Detailed Implementation

[0042] The present invention will now be described in detail. It should be noted that, in this specification, for example, "(meth)acryloyloxy" means one or both of "acryloyloxy" and "methacryloyloxy", and "(meth)acrylic acid" means one or both of "acrylic acid" and "methacrylic acid".

[0043] (Resin particles)

[0044] The resin particles of the present invention comprise a resin particle body and a plurality of silica particles. In the resin particles of the present invention, a plurality of the aforementioned silica particles are present on the surface or inside the resin particle body. In the resin particles of the present invention, the resin particle body is a polymer of a polymeric component, the polymeric component comprising a polymeric compound having one or more maleimide groups.

[0045] Because the resin particles of the present invention have the above-described structure, they can exhibit both low thermal expansion and low dielectric properties. The resin particles of the present invention achieve a balance between low thermal expansion and low dielectric properties. Even when exposed to high temperatures, the resin particles of the present invention are not prone to thermal expansion, thus improving dimensional stability.

[0046] In the resin particles of the present invention, a plurality of the aforementioned silica particles may exist on the surface (exterior) of the resin particle body, or inside the resin particle body, or both on the surface (exterior) and inside the resin particle body.

[0047] In the aforementioned resin particles, any single silica particle may be entirely present on the surface (exterior) of the resin particle body, or a portion of any single silica particle may be present (exposed) on the surface (exterior) of the resin particle body. In the aforementioned resin particles, any single silica particle may be entirely present inside the resin particle body, or a portion of any single silica particle may be present inside the resin particle body. Alternatively, any single silica particle may have a portion present inside the resin particle body (a portion of a silica particle) and a portion present on the surface of the resin particle body (a portion of a silica particle (the remainder)).

[0048] Figure 4 It is a schematic cross-sectional view used to illustrate the location of silica particles contained in resin particles.

[0049] about Figure 4The silica particles X shown are entirely present on the surface of the aforementioned resin particle body. Regarding... Figure 4 The silica particle Y shown is entirely present within the aforementioned resin particle matrix. Regarding... Figure 4 The silica particles Z shown have a portion present inside the resin particle body and a portion (the remainder) present on the surface of the resin particle body. The resin particles may contain silica particles X, silica particles Y, or silica particles Z.

[0050] In the aforementioned resin particles, all of the aforementioned silica particles may be present on the surface (exterior) of the resin particle body, or at least a portion (of the silica particles) may be present on the surface (exterior) of the resin particle body. Alternatively, all of the aforementioned silica particles may be present on the surface (exterior) of the resin particle body, or at least one of the aforementioned silica particles may be present on the surface (exterior) of the resin particle body. Alternatively, all of the aforementioned silica particles may be present inside the resin particle body, or at least a portion (of the silica particles) may be present inside the resin particle body. Finally, all of the aforementioned silica particles may be present inside the resin particle body, or at least one of the aforementioned silica particles may be present inside the resin particle body.

[0051] The aforementioned resin particles may contain: silica particles present on the surface (outer side) of the resin particle body; silica particles present on both the surface (outer side) and interior (partially present on the exterior side) of the resin particle body; and silica particles present inside the resin particle body. From the viewpoint of further improving water repellency, it is preferable that in at least one of the plurality of silica particles, a portion of the silica particles is present inside the resin particle body, and a portion of the silica particles is present (exposed) on the surface (outer side) of the resin particle body. From the viewpoint of further improving water repellency, it is preferable that at least one of the plurality of silica particles has a portion present inside the resin particle body (a portion of one silica particle) and a portion present (exposed) on the surface (outer side) of the resin particle body (a portion of one silica particle (the remainder)). From the viewpoint of further effectively exhibiting low thermal expansion, it is preferable that in a portion (at least one) of the silica particles, a portion of the silica particles is present inside the resin particle body, and a portion of the silica particles is present (exposed) on the surface (outer side) of the resin particle body. From the viewpoint of further improving low thermal expansion resistance, it is preferable that a portion (at least one) of the aforementioned silica particles has a portion existing inside the resin particle body (a portion of a silica particle) and a portion existing (exposed) on the surface (outside) of the resin particle body (a portion of a silica particle (the remainder)). Among the aforementioned resin particles, it is preferable that: silica particles exist only on the surface (outside) of the resin particle body; silica particles exist on both the surface and inside the resin particle body (a portion exists on the outside of the resin particle body); and silica particles exist only inside the resin particle body. In these cases, low thermal expansion resistance can be further effectively achieved.

[0052] The present invention will now be described in detail with reference to the accompanying drawings.

[0053] Figure 1 This is a schematic cross-sectional view illustrating resin particles according to the first embodiment of the present invention.

[0054] Figure 1 The resin particle 1 shown comprises a resin particle body 2 and a plurality of silica particles 3. In the resin particle 1, all the silica particles 3 are present both on the surface (exterior) and inside the resin particle body 2. In the resin particle 1, a portion of the silica particles 3 are present inside the resin particle body 2, and a portion of the silica particles 3 are present on the surface (exterior) of the resin particle body 2.

[0055] Figure 2 This is a schematic cross-sectional view illustrating resin particles according to the second embodiment of the present invention.

[0056] Figure 2 The resin particle 1A shown comprises a resin particle body 2 and a plurality of silica particles 3A. In resin particle 1A, at least one of the plurality of silica particles 3A is present inside the resin particle body 2. In resin particle 1A, a portion (at least one) of the silica particles 3A is present inside the resin particle body 2. In resin particle 1A, a plurality of silica particles 3A are dispersed in the resin particle body 2. In resin particle 1A, the plurality of silica particles 3A are present on both the surface (exterior) and interior of the resin particle body 2. In resin particle 1A, a portion (at least one) of the silica particles 3A is present on both the surface (exterior) and interior of the resin particle body 2. In resin particle 1A, in at least one of the plurality of silica particles 3A, a portion of the silica particles 3A is present inside the resin particle body 2, and a portion of the silica particles 3A is present on both the surface (exterior) and interior of the resin particle body 2.

[0057] The resin particles 1A contain: silica particles 3A that are entirely present inside the resin particle body 2, and silica particles 3A that are partially present on the surface (outside) of the resin particle body 2.

[0058] The thermal expansion coefficient of the aforementioned resin particles at 50°C to 150°C is preferably less than 150 ppm / °C, more preferably less than 120 ppm / °C, even more preferably less than 110 ppm / °C, even more preferably less than 100 ppm / °C, even more preferably less than 90 ppm / °C, particularly preferably less than 80 ppm / °C, even more preferably less than 80 ppm / °C, even more preferably less than 70 ppm / °C, even more preferably less than 60 ppm / °C, and most preferably less than 50 ppm / °C. When the aforementioned thermal expansion coefficient is below (or below) the upper limit of the above-mentioned limit, low thermal expansion can be effectively achieved, and the dimensional change of the resin particles when exposed to high temperatures can be reduced. Therefore, for example, when the resin particles are used in insulating layers, even if the insulating layer is exposed to high temperatures, the generation of peeling and cracking can be suppressed. The thermal expansion coefficient of the aforementioned resin particles at 50°C to 150°C can be 0 ppm / °C or higher. The range of the thermal expansion coefficient of the aforementioned resin particles at 50°C to 150°C can be appropriately set by selecting the aforementioned lower limit and upper limit values.

[0059] The thermal expansion coefficient of the aforementioned resin particles at 50°C to 150°C can be determined, for example, as described below. Using thermomechanical analysis (TMA), the resin particles are held at 50°C for 5 minutes, and then heated from 50°C to 160°C at a heating rate of 5°C / min. The coefficient of linear expansion from 50°C (at the start of heating) to 150°C (when reaching 150°C) is calculated. For example, a thermomechanical analysis (TMA) instrument such as the "TMA450" manufactured by TA Instruments can be used.

[0060] The dielectric constant of the aforementioned resin particles is preferably below 2.90 F / m, more preferably below 2.80 F / m, further preferably below 2.70 F / m, even more preferably below 2.70 F / m, particularly preferably below 2.60 F / m, particularly further preferably below 2.50 F / m, even more particularly preferably below 2.50 F / m, and most preferably below 2.40 F / m. When the dielectric constant of the aforementioned resin particles is below (or less than) the aforementioned upper limit, the low dielectric properties can be further effectively achieved. The lower limit of the dielectric constant of the aforementioned resin particles is not particularly limited. The dielectric constant of the aforementioned resin particles can be 1.80 F / m or more, or 1.90 F / m or more. The range of the dielectric constant of the aforementioned resin particles can be appropriately set by selecting the aforementioned lower limit and the aforementioned upper limit.

[0061] The dielectric loss tangent of the aforementioned resin particles is preferably 0.01 or less, more preferably less than 0.01, even more preferably less than 0.008, even more preferably less than 0.005, particularly preferably less than 0.005, and most preferably less than 0.003. When the dielectric loss tangent of the aforementioned resin particles is below (or equal to) the aforementioned upper limit, low dielectric properties can be further effectively achieved. The lower limit of the dielectric loss tangent of the aforementioned resin particles is not particularly limited. The dielectric loss tangent of the aforementioned resin particles can be 0.0001 or more, or 0.0005 or more. The range of the dielectric loss tangent of the aforementioned resin particles can be appropriately set by selecting the aforementioned lower limit and upper limit values.

[0062] The dielectric constant and dielectric loss tangent of the aforementioned resin particles can be measured, for example, as described below. Resin particles are filled into a quartz tube and placed in a resonator for powder measurement. The dielectric constant and dielectric loss tangent of the aforementioned resin particles at 1 GHz are measured using a dielectric constant measuring device (manufactured by AET Corporation).

[0063] The preferred 10% K value for the above-mentioned resin particles at 25°C is 100 N / mm. 2 The above, and more preferably, is 500 N / mm 2 The above, and more preferably, is 1000 N / mm 2 The above is preferably 20000 N / mm.2 The following is more preferably 15000 N / mm 2 The following, and more preferably, is 10000 N / mm 2 The following, particularly preferred, is 8000 N / mm. 2 The following applies: When the 10% K value of the above-mentioned resin particles at 25°C is above the lower limit and below the upper limit, the interfacial delamination between the silica particles and the resin particle body can be suppressed.

[0064] The 10% K value of the aforementioned resin particles at 25°C can be determined as follows: Using a micro compression tester, the resin particles are compressed at 25°C under a maximum test load of 20 mN for 60 seconds using the smooth end face of a cylindrical (50 μm diameter, diamond) indenter. The load value (N) and compression displacement (mm) are measured. The 10% K value of the aforementioned resin particles at 25°C can be calculated from the measured values ​​using the following formula. For example, a FISCHERSCOPE H-100 manufactured by FISCHER Corporation can be used as the micro compression tester.

[0065] 10% K value (N / mm) 2 ) = (3 / 2 1 / 2 )·F·S -3 / 2 ·R -1 / 2

[0066] F: Load value (N) when resin particles undergo 10% compressive deformation.

[0067] S: Compression displacement (mm) when resin particles undergo 10% compression deformation.

[0068] R: Radius of the resin particle (mm)

[0069] From the viewpoint of suppressing the destruction of resin particles during the molding of a composition containing resin particles, the compression recovery rate of the aforementioned resin particles at 25°C is preferably 10% or more, more preferably 20% or more, further preferably 30% or more, preferably 95% or less, more preferably 90% or less, and further preferably 80% or less. The compression recovery rate of the aforementioned resin particles at 25°C may be 70% or less.

[0070] The compression recovery rate of the above resin particles at 25°C can be determined as follows.

[0071] Resin particles are dispersed on the test stage. For each dispersed resin particle, a micro compression tester is used. A load of 1.0 mN is applied at the origin, with a smooth cylindrical indenter (50 μm in diameter, made of diamond), at 25°C, towards the center of the resin particle, and a reverse load of 10 mN. The recovery behavior after the load is removed is analyzed, and the compression recovery rate is derived. The load-compression displacement during this period can be measured, and the compression recovery rate can be calculated using the following formula. It should be noted that the load speed is set to 0.33 mN / second. For example, a FISCHERSCOPE H-100 micro compression tester can be used.

[0072] Compression recovery rate (%) = [L2 / L1] × 100

[0073] L1: The compressive displacement from the origin (load value) to the reverse load value when a load is applied.

[0074] L2: Unloading displacement from the reverse load value to the original load value during load removal.

[0075] From the viewpoint of further improving the dispersibility of resin particles in solvent, the particle size of the above-mentioned resin particles is preferably 0.5 μm or more, more preferably 1.0 μm or more, even more preferably 3.0 μm or more, particularly preferably 5.0 μm or more, preferably 100 μm or less, more preferably 50 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less.

[0076] The particle size of the aforementioned resin particles refers to the diameter when the resin particles are perfectly spherical, and to the diameter when the resin particles are in a shape other than perfectly spherical, assuming they are spheres with a volume equivalent to that of the particle.

[0077] The particle size of the aforementioned resin particles is preferably the average particle size, and more preferably the number-average particle size. The particle size of the resin particles can be measured using any particle size distribution measuring device. For example, a particle size distribution measuring device utilizing principles such as laser light scattering, resistance value changes, or post-capture image analysis can be used. More specifically, as a method for measuring the particle size of resin particles, an example is using a particle size distribution measuring device (BECKMAN COULTER's "Multisizer4") to measure the particle size of approximately 100,000 resin particles and calculate the average value.

[0078] From the viewpoint of further improving the dispersibility of resin particles in a solvent, the coefficient of variation (CV) of the particle size of the aforementioned resin particles is preferably 30% or less, more preferably 20% or less, and even more preferably 10% or less. The lower limit of the coefficient of variation (CV) of the particle size of the aforementioned resin particles is not particularly limited. The coefficient of variation (CV) of the particle size of the aforementioned resin particles can be 0% or more, or 1% or more. The range of the coefficient of variation (CV) of the particle size of the aforementioned resin particles can be appropriately set by selecting the aforementioned lower limit and the aforementioned upper limit.

[0079] The coefficient of variation (CV) of the particle size of the above resin particles can be determined as follows.

[0080] The CV value (%) of the above resin particle size is calculated as follows: (ρ / Dn) × 100

[0081] ρ: Standard deviation of the particle size of the above resin particles

[0082] Dn: The average particle size of the above resin particles

[0083] The shape of the resin particles is not particularly limited. The resin particles may be spherical, or other shapes, or flat, etc. From the viewpoint of further improving the dispersibility of the resin particles in the solvent, the shape of the resin particles is preferably spherical.

[0084] From the viewpoint of further improving the dispersibility of resin particles in a solvent, the aspect ratio of the resin particles is preferably 1.5 or less, more preferably 1.3 or less, and even more preferably 1.1 or less. The lower limit of the aspect ratio of the resin particles is not particularly limited. The aspect ratio of the resin particles can be 1.0 or more, or 1.1 or more. From the viewpoint of further improving the dispersibility of resin particles in a solvent, the aspect ratio of the resin particles is most preferably 1.0. The range of the aspect ratio of the resin particles can be appropriately set by selecting the aforementioned lower limit and upper limit values.

[0085] The above aspect ratio represents the length of the major diameter / minor diameter. The above aspect ratio is preferably obtained by observing 10 arbitrary resin particles using an electron microscope or an optical microscope, taking the largest and smallest diameters as the major and minor diameters respectively, and calculating the average length of the major diameter / minor diameter of each spherical resin particle.

[0086] From the viewpoint of preventing resin particles from settling in the solvent and further improving the dispersibility of resin particles in the solvent, the specific gravity of the resin particles is preferably 1.6 or less, more preferably 1.5 or less, even more preferably 1.4 or less, and particularly preferably 1.3 or less. The specific gravity of the resin particles can be 0.8 or more, 0.90 or more, 0.95 or more, 0.98 or more, 0.99 or more, or 1.0 or more. The range of the specific gravity of the resin particles can be appropriately set by selecting the aforementioned lower limit and upper limit values.

[0087] The resin particles described above are preferably dispersed in a solvent for use. The resin particles are preferably dispersed in a solvent and used in the form of a composition. The solvent for dispersing the resin particles can be aqueous or oil-based. Examples of solvents for dispersing the resin particles include: silicone, water, mineral oil, polyether derivatives; alcohols such as methanol, ethanol, isopropanol, and fluorinated alcohols; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran, diethyl ether, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, and cyclic ethers; esters such as acetate, pyruvate, 2-hydroxyisobutyric acid, and lactate; amides such as dimethylformamide; aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as octane and decane; and resins. Examples of resins include: rubber, vinyl resins, acrylic resins, urethane resins, melamine resins, polyester resins, polyol resins, engineering plastics, silicone resins, fluoropolymers, and epoxy resins. When the resin particles are dispersed in a solvent for use in a liquid state, the solvent is preferably a siloxane, water, mineral oil, polyether derivative, etc. Compositions formed by dispersing the resin particles in these solvents are particularly suitable for use as lubricants and non-adhesives. When the resin particles are dispersed in a solvent and then the solvent is vaporized for use, the solvent is preferably an alcohol such as methanol, ethanol, isopropanol, or fluorinated alcohols; a ketone such as acetone or methyl ethyl ketone; an ether such as tetrahydrofuran, diethyl ether, ethylene glycol monoalkyl ether, propylene glycol monoalkyl ether, or cyclic ether; an ester such as acetate, pyruvate, 2-hydroxyisobutyric acid, or lactate; an amide such as dimethylformamide; aromatic hydrocarbons such as toluene or xylene; aliphatic hydrocarbons such as octane or decane; and water. Compositions formed by dispersing the resin particles in these solvents are particularly suitable for use in inks, coatings, paints, and photosensitive materials. Compositions formed by dispersing the resin particles in the above-mentioned resin are particularly suitable for use in coatings, paints, non-adhesive additives, and anti-drip additives.

[0088] The composition comprising the aforementioned resin particles and solvent can be used for coating using an inkjet printer, screen printing, or a dispensing method. Generally, existing composite particles containing fluorinated resins tend to settle when dispersed in a solvent, sometimes making it difficult to improve inkjet ejection performance. On the other hand, the aforementioned resin particles, due to their specific structure, exhibit improved inkjet ejection performance when dispersed in a solvent.

[0089] From the viewpoint of further improving the dispersibility of resin particles in solvent, the specific gravity of the solvent in which the resin particles are dispersed is preferably 0.5 or more, more preferably 0.7 or more, even more preferably 0.8 or more, preferably 1.5 or less, more preferably 1.3 or less, and even more preferably 1.1 or less.

[0090] This specification discloses a dispersion comprising the aforementioned resin particles and a solvent. Specific resin particles are used in this dispersion, resulting in excellent dispersibility of the resin particles. From the viewpoint of further improving the dispersibility of the resin particles in the solvent, the aforementioned resin particles are preferably dispersed in toluene or an epoxy resin. The aforementioned dispersion may contain toluene or an epoxy resin. Since the effects of the present invention can be effectively achieved, the aforementioned dispersion is preferably a material for an insulating layer.

[0091] The components of the resin particles are described in detail below.

[0092] <Resin Particle Body>

[0093] The aforementioned resin particles comprise a resin particle body. Both the resin particles and the resin particle body contain resin. In the aforementioned resin particles, the resin particle body is a polymer of a polymerizable component. The polymerizable component comprises a polymeric compound having one or more olefinically unsaturated groups. Specifically, the polymeric component comprises a polymeric compound having one or more maleimide groups. From the viewpoint of effectively achieving the effects of the present invention, the polymeric component preferably comprises a polymeric compound having two or more olefinically unsaturated groups, more preferably a polymeric compound having two or more maleimide groups. From the viewpoint of effectively achieving the effects of the present invention, the aforementioned resin particle body preferably comprises a polymer of a polymeric compound having one or more olefinically unsaturated groups, more preferably a polymer of a polymeric compound having one or more maleimide groups. From the viewpoint of effectively achieving the effects of the present invention, the aforementioned resin particle body preferably comprises a polymer of a polymeric compound having two or more olefinically unsaturated groups, more preferably a polymer of a polymeric compound having two or more maleimide groups.

[0094] Examples of polymeric compounds (monomers) having one or more olefinic unsaturated groups include polymeric compounds having one olefinic unsaturated group and polymeric compounds having two or more olefinic unsaturated groups. The polymeric compounds having two or more olefinic unsaturated groups may have 100 or fewer olefinic unsaturated groups. Examples of polymeric compounds (monomers) having one or more maleimide groups include polymeric compounds having one maleimide group and polymeric compounds having two or more maleimide groups. The polymeric compounds having two or more maleimide groups may have 100 or fewer maleimide groups. Only one type of polymeric compound having one or more olefinic unsaturated groups may be used, or two or more may be used in combination. The polymeric compounds having two or more olefinic unsaturated groups described above may be used in combination with only one type or in combination with two or more types. The polymeric compounds having one or more maleimide groups described above may be used in combination with only one type or in combination with two or more types. The polymeric compounds having one maleimide group described above may be used in combination with only one type or in combination with two or more types. The polymeric compounds having two or more maleimide groups described above may be used in combination with only one type or in combination with two or more types. The range of the number of maleimide groups in the polymeric compounds having one or more maleimide groups (and the polymeric compounds having two or more maleimide groups described above) may be appropriately set by selecting the lower and upper limits described in this specification. The range of the number of olefinic unsaturated groups in the polymeric compounds having one or more olefinic unsaturated groups described above (or the polymeric compounds having two or more olefinic unsaturated groups described above) may be appropriately set by selecting the lower and upper limits described in this specification.

[0095] Examples of polymeric compounds (monomers) having one or more olefinic unsaturated groups include polymeric compounds having one olefinic unsaturated group and polymeric compounds having two or more olefinic unsaturated groups. The polymeric compounds having two or more olefinic unsaturated groups may have fewer than 100 olefinic unsaturated groups, or fewer than 10.

[0096] Examples of non-crosslinking monomers include: styrene monomers such as styrene and α-methylstyrene; carboxyl-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride; alkyl esters of (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate; and 2-hydroxyethyl (meth)acrylate, glyceryl (meth)acrylate, and polyoxyethylene (POE). Oxygen-containing (meth)acrylates such as methacrylates and glycidyl methacrylate; nitrile monomers such as methacrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; vinyl acetates such as vinyl butyrate, vinyl laurate, and vinyl stearate; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; halogen-containing monomers such as trifluoromethyl methacrylate, pentafluoroethyl methacrylate, perfluorohexyl methacrylate, vinyl chloride, vinyl fluoride, and chlorostyrene; and polymeric compounds with one maleimide group.

[0097] Examples of monomers exhibiting the aforementioned crosslinking properties include: tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol ... Polyfunctional (meth)acrylates such as tetramethylene glycol di(meth)acrylate and 1,4-butanediol di(meth)acrylate; silane-containing monomers such as triallyl (iso)cyanurate, triallyl trimellitic acid, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, γ-(meth)acryloyloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane; and polymerizable compounds having two or more maleimide groups. The aforementioned polymerizable compounds having two or more maleimide groups can be either compounds with two maleimide groups or bismaleimide compounds. These polymerizable compounds having two or more maleimide groups can have fewer than 100 maleimide groups or fewer than 10 maleimide groups.

[0098] From the viewpoint of achieving the effects of the present invention, and particularly from the viewpoint of achieving low dielectric properties, the aforementioned polymeric compound (polymeric component) having an olefinically unsaturated group comprises a polymeric compound having one or more maleimide groups. From the viewpoint of further effectively achieving the effects of the present invention, and particularly from the viewpoint of further effectively achieving low dielectric properties, the aforementioned polymeric compound (polymeric component) having an olefinically unsaturated group preferably comprises a polymeric compound having two or more maleimide groups, and more preferably comprises a bismaleimide compound.

[0099] From the viewpoint of further effectively exhibiting solvent resistance and chemical resistance, the aforementioned polymeric component preferably includes a crosslinking monomer (hereinafter, sometimes referred to as crosslinking monomer (X)) that differs from polymeric compounds having one or more maleimide groups. From the viewpoint of further effectively exhibiting solvent resistance and chemical resistance, the aforementioned crosslinking monomer (X) preferably includes divinylbenzene or a polymeric compound having two or more (meth)acryloyl groups. The aforementioned polymeric compound having two or more (meth)acryloyl groups may have 100 or fewer (meth)acryloyl groups, or 10 or fewer. The range of the number of (meth)acryloyl groups in the aforementioned polymeric compound having two or more (meth)acryloyl groups can be appropriately set by selecting the aforementioned lower limit and the aforementioned upper limit.

[0100] The aforementioned resin particle matrix can be obtained by polymerizing the polymeric compound having one or more olefinic unsaturated groups using a known method. Examples of such methods include suspension polymerization in the presence of a free radical polymerization initiator, and polymerization by swelling the polymeric compound together with non-crosslinked seed particles and a free radical polymerization initiator.

[0101] The particle size of the aforementioned resin particles is preferably 0.5 μm or more, more preferably 1.0 μm or more, further preferably 3.0 μm or more, particularly preferably 5.0 μm or more, preferably 100 μm or less, more preferably 50 μm or less, further preferably 30 μm or less, and particularly preferably 20 μm or less. When the particle size of the aforementioned resin particles is above or below the aforementioned lower limit and below the aforementioned upper limit, the dispersibility and water repellency of the resin particles in the solvent can be further improved.

[0102] The particle size of the aforementioned resin particle body refers to the diameter when the aforementioned resin particle body is a perfect sphere, and when the aforementioned resin particle body is not a perfect sphere, it refers to the diameter when it is assumed to be a perfect sphere with a volume equivalent to that of the particle.

[0103] The particle size of the aforementioned resin particle bulk is preferably the average particle size, and more preferably the number-average particle size. The particle size of the aforementioned resin particle bulk can be measured using any particle size distribution measuring device. For example, a particle size distribution measuring device utilizing principles such as laser light scattering, resistance value changes, or post-capture image analysis can be used. More specifically, as a method for measuring the particle size of the aforementioned resin particle bulk, an example is using a particle size distribution measuring device (BECKMAN COULTER's "Multisizer4") to measure the particle size of approximately 100,000 resin particle bulks and calculate the average particle size.

[0104] From the viewpoint of further improving the dispersibility of resin particles in a solvent, the coefficient of variation (CV) of the particle size of the aforementioned resin particle bulk is preferably 30% or less, more preferably 20% or less, and even more preferably 10% or less. The lower limit of the coefficient of variation (CV) of the particle size of the aforementioned resin particle bulk is not particularly limited. The coefficient of variation (CV) of the particle size of the aforementioned resin particle bulk can be 0% or more, or 1% or more. The range of the coefficient of variation (CV) of the particle size of the aforementioned resin particle bulk can be appropriately set by selecting the aforementioned lower limit and the aforementioned upper limit.

[0105] The coefficient of variation (CV) of the particle size of the above-mentioned resin particles can be determined as follows.

[0106] The CV value (%) of the above resin particle bulk size is calculated as follows: (ρ / Dn) × 100

[0107] ρ: Standard deviation of the particle size of the above-mentioned resin particles

[0108] Dn: The average particle size of the above-mentioned resin particle bulk.

[0109] The shape of the resin particle body is not particularly limited. The shape of the resin particle body can be spherical, or a shape other than spherical, or flat, etc.

[0110] Of the 100% by weight of resin particles, the content of the main resin particle component is preferably 40% by weight or more, more preferably 50% by weight or more, even more preferably 60% by weight or more, even more preferably 70% by weight or more, even more preferably 80% by weight or more, particularly preferably 90% by weight or more, most preferably 95% by weight or more, preferably 99.9% by weight or less, more preferably 99% by weight or less, and even more preferably 98% by weight or less. When the content of the main resin particle component is at or above the lower limit and below the upper limit, the dispersibility of the resin particles in the solvent can be further improved.

[0111] In the above-mentioned 100% by weight of polymerizable components, the content of the polymeric compound having one or more olefinic unsaturated groups is preferably 40% by weight or more, more preferably 50% by weight or more, further preferably 60% by weight or more, further preferably 70% by weight or more, even more preferably 80% by weight or more, particularly preferably 85% by weight or more, particularly further preferably 90% by weight or more, most preferably 95% by weight or more, and preferably 100% by weight or less. When the content of the polymeric compound having one or more olefinic unsaturated groups is at or above the above-mentioned lower limit, solvent resistance and chemical resistance can be improved. The upper limit of the content of the polymeric compound having one or more olefinic unsaturated groups is not particularly limited. In the above-mentioned 100% by weight of polymerizable components, the content of the polymeric compound having one or more olefinic unsaturated groups can be 100% by weight (total amount) or less than 100% by weight.

[0112] In the above-mentioned 100% by weight of polymerizable components, the content of the polymerizable compound having two or more olefinic unsaturated groups is preferably 40% by weight or more, more preferably 50% by weight or more, further preferably 60% by weight or more, further preferably 70% by weight or more, even more preferably 80% by weight or more, particularly preferably 85% by weight or more, particularly further preferably 90% by weight or more, most preferably 95% by weight or more, and preferably 100% by weight or less. When the content of the polymerizable compound having two or more olefinic unsaturated groups is at or above the above-mentioned lower limit, solvent resistance and chemical resistance can be improved. The upper limit of the content of the polymerizable compound having two or more olefinic unsaturated groups is not particularly limited. In the above-mentioned 100% by weight of polymerizable components, the content of the polymerizable compound having two or more olefinic unsaturated groups can be 100% by weight (total amount) or less than 100% by weight.

[0113] In the aforementioned 100% by weight of polymerizable components, the content of the polymerizable compound having one or more maleimide groups is preferably 1% by weight or more, more preferably 5% by weight or more, further preferably 10% by weight or more, even more preferably 20% by weight or more, particularly preferably 30% by weight or more, most preferably 50% by weight or more, and preferably 100% by weight or less. When the content of the polymerizable compound having one or more maleimide groups is at or above the aforementioned lower limit, the low dielectric properties can be further effectively achieved. The upper limit of the content of the polymerizable compound having one or more maleimide groups is not particularly limited. In the aforementioned 100% by weight of polymerizable components, the content of the polymerizable compound having one or more maleimide groups can be 100% by weight (total amount) or less than 100% by weight.

[0114] In the aforementioned 100% by weight of polymerizable components, the content of the polymerizable compound having two or more maleimide groups is preferably 1% by weight or more, more preferably 5% by weight or more, further preferably 10% by weight or more, even more preferably 20% by weight or more, particularly preferably 30% by weight or more, most preferably 50% by weight or more, and preferably 100% by weight or less. When the content of the aforementioned polymerizable compound having two or more maleimide groups is at or above the aforementioned lower limit, the low dielectric properties can be further effectively achieved. The upper limit of the content of the aforementioned polymerizable compound having two or more maleimide groups is not particularly limited. In the aforementioned 100% by weight of polymerizable components, the content of the aforementioned polymerizable compound having two or more maleimide groups can be 100% by weight (total amount) or less than 100% by weight.

[0115] When the polymerizable component includes the crosslinking monomer (X), the content of the crosslinking monomer (X) in 100% by weight of the polymerizable component is preferably more than 0% by weight, more preferably 1% by weight or more, further preferably 5% by weight or more, more preferably 10% by weight or more, even more preferably 20% by weight or more, particularly preferably 30% by weight or more, particularly more preferably 40% by weight or more, and most preferably 50% by weight or more. When the content of the crosslinking monomer (X) is at or above the aforementioned lower limit, low thermal expansion can be further effectively achieved. The upper limit of the content of the crosslinking monomer (X) is not particularly limited. In 100% by weight of the polymerizable component, the content of the crosslinking monomer (X) can be 99% by weight or less, 95% by weight or less, 90% by weight or less, 80% by weight or less, 70% by weight or less, 60% by weight or less, or 50% by weight or less. In the above-mentioned polymeric component 100% by weight, the range of the content of the above-mentioned crosslinking monomer (X) can be appropriately set by selecting the above-mentioned lower limit value and the above-mentioned upper limit value.

[0116] <Silica particles>

[0117] The aforementioned resin particles contain multiple silica particles.

[0118] Of the silica particles present on the surface (outside) of the resin particle body, the volume of the portion present on the surface (outside) of the resin particle body out of 100% by volume is preferably 10% by volume or more, more preferably 20% by volume or more, and even more preferably 30% by volume or more. The volume of the portion present on the surface (outside) of the resin particle body out of 100% by volume is preferably 99% by volume or less, more preferably 90% by volume or less, and even more preferably 80% by volume or less. When the volume of the portion present on the surface (outside) of the resin particle body is above or below the aforementioned lower limit and below the aforementioned upper limit, low thermal expansion can be further effectively achieved. The range of the volume of the portion present on the surface (outside) of the resin particle body out of 100% by volume can be appropriately set by selecting the aforementioned lower limit and the aforementioned upper limit.

[0119] From the viewpoint of further effectively utilizing low thermal expansion, in the aforementioned resin particles, of the total number of silica particles, the number of silica particles present on the surface (outside) of the resin particle body is preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, and preferably 100% or less. It should be noted that when observing a single silica particle, if all or part of that silica particle is present (exposed) on the surface (outside) of the resin particle body, that silica particle is determined to be equivalent to silica particles present on the surface (outside) of the resin particle body. When observing a single silica particle, if at least a portion of that silica particle is present (exposed) on the surface (outside) of the resin particle body, that silica particle is determined to be equivalent to silica particles present on the surface (outside) of the resin particle body. When observing a single silica particle, if the silica particle as a whole is not present on the surface (outside) of the resin particle body, it is determined that the silica particle is not equivalent to a silica particle present on the surface (outside) of the resin particle body.

[0120] In the aforementioned resin particles, a plurality of silica particles may be dispersed on the surface (exterior) of the resin particle body, or they may exist unevenly. From the viewpoint of further effectively utilizing low thermal expansion, it is preferable that a plurality of silica particles are dispersed on the surface (exterior) of the resin particle body.

[0121] The particle size of the aforementioned silica particles is preferably 10 nm or more, more preferably 20 nm or more, even more preferably 100 nm or more, preferably 1.0 μm or less, more preferably less than 1.0 μm, even more preferably 500 nm or less, particularly preferably 400 nm or less, and most preferably 350 nm or less. When the particle size of the aforementioned silica particles is above or below the aforementioned lower limit and below the aforementioned upper limit (or below the aforementioned upper limit), it is possible to suppress the aggregation of silica particles on or within the surface of the resin particle body. In addition, when the particle size of the silica particles is below the aforementioned upper limit (or below the aforementioned upper limit), it is possible to further effectively exhibit low thermal expansion properties. From the viewpoint of further effectively exhibiting low thermal expansion properties, the particle size of the aforementioned silica particles is particularly preferably 1.0 μm or less.

[0122] The particle size of the aforementioned silica particles is preferably equal to or less than the particle size of the aforementioned resin particles, and more preferably smaller than the particle size of the aforementioned resin particles. The ratio of the particle size of the aforementioned silica particles to the particle size of the aforementioned resin particles is denoted as the ratio (particle size of silica particles / particle size of resin particles). The aforementioned ratio (particle size of silica particles / particle size of resin particles) is preferably 0.001 or more, more preferably 0.01 or more, further preferably 0.03 or more, preferably 0.5 or less, more preferably 0.3 or less, further preferably 0.1 or less, and particularly preferably 0.06 or less. When the aforementioned ratio (particle size of silica particles / particle size of resin particles) is at or above the aforementioned lower limit and below the aforementioned upper limit, it is possible to suppress the aggregation of silica particles on or within the surface of the aforementioned resin particle body.

[0123] The particle size of the aforementioned silica particles refers to the diameter when the silica particles are perfectly spherical, and to the diameter when the silica particles are not perfectly spherical, assuming they are spheres of similar volume.

[0124] The particle size of the aforementioned silica particles is preferably the average particle size, and more preferably the number-average particle size. The particle size of the silica particles can be measured using any particle size distribution measuring device. For example, a particle size distribution measuring device utilizing principles such as laser light scattering, resistance value changes, or post-capture image analysis can be used. More specifically, as a method for measuring the particle size of silica particles, an example is using a particle size distribution measuring device (BECKMAN COULTER "LS13 320") to measure the particle size of silica particles and calculate the average value. The particle size of the aforementioned silica particles can also be measured by observing the cross-section of resin particles.

[0125] From the viewpoint of further improving the dispersibility of resin particles in solvents, the coefficient of variation (CV) of the particle size of the aforementioned silica particles is preferably 1% or more, preferably 30% or less, more preferably 20% or less, and even more preferably 10% or less. The range of the coefficient of variation (CV) of the particle size of the aforementioned silica particles can be appropriately set by selecting the aforementioned lower limit and the aforementioned upper limit.

[0126] The coefficient of variation (CV) of the particle size of the aforementioned silica particles can be determined as follows.

[0127] The CV value (%) of the particle size of the above-mentioned silica particles = (ρ / Dn) × 100

[0128] ρ: Standard deviation of the particle size of the above-mentioned silica particles

[0129] Dn: The average particle size of the above-mentioned silica particles

[0130] The shape of the aforementioned silica particles is not particularly limited. The silica particles can be spherical, or other shapes, or flat, etc.

[0131] From the viewpoint of further effectively exhibiting low thermal expansion, it is preferable that the number of silica particles present in the region (R2) extending from the surface of the resin particle body towards the center to half its thickness is greater than the number of silica particles present in the region (R1) extending from the center of the resin particle body towards the surface to half its thickness. From the viewpoint of further effectively exhibiting low thermal expansion, it is preferable that the number of silica particles present on the surface of the resin particle body is greater than the number of silica particles present inside the resin particle body.

[0132] The number of silica particles present in the aforementioned regions (R1) and (R2) can be determined, for example, as described below.

[0133] An epoxy resin body for resin particle inspection was prepared by adding resin particles to an epoxy resin to achieve a resin particle content of 30% by weight and dispersing them. A cross-section polisher (NICP) (JEOL Ltd. "IB-09010CP") was used to cut a cross-section of the resin particles near the center of the resin particles dispersed in the resin particle inspection embedded resin body. Then, using a FIB-SEM (FEI Ltd. "Helios Nanolab 650") at 10 kV and 200 pA, 10 resin particles were randomly selected, and the silica particles in each resin particle were observed. For the cross-section of the resin particles, the number of silica particles present in the region (R2) extending from the surface of the resin particle body towards the center to half the thickness, and the number of silica particles present in the region (R1) extending from the center of the resin particle body towards the surface to half the thickness, were measured, and the average value was calculated.

[0134] The ratio of the number of silica particles present in region (R2) to the number of silica particles present in region (R1) is defined as the ratio (number of silica particles present in region (R2) / number of silica particles present in region (R1)). This ratio (number of silica particles present in region (R2) / number of silica particles present in region (R1)) is preferably 1.0 or more, more preferably 2.0 or more, further preferably 3.0 or more, and particularly preferably 4.0 or more. When this ratio (number of silica particles present in region (R2) / number of silica particles present in region (R1)) is at or above the lower limit, the water repellency can be further improved, and the dielectric loss tangent can be further reduced. This ratio (number of silica particles present in region (R2) / number of silica particles present in region (R1)) can be 100 or less, or 10 or less. The range of the above ratio (the number of silica particles present in region (R2) / the number of silica particles present in region (R1)) can be set by appropriately selecting the above lower limit and the above upper limit.

[0135] In the 100% by weight of the aforementioned resin particles, the content of the aforementioned silica particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, further preferably 1.0% by weight or more, and particularly preferably 3.0% by weight or more. In the 100% by weight of the aforementioned resin particles, the content of the aforementioned silica particles is preferably 35% by weight or less, more preferably 30% by weight or less, further preferably 20% by weight or less, particularly preferably 15% by weight or less, and most preferably 10% by weight or less. When the content of the aforementioned silica particles is above or below the aforementioned lower limit and below the aforementioned upper limit, low thermal expansion can be further effectively achieved. When the content of the aforementioned silica particles is below the aforementioned upper limit, the dispersibility of the resin particles in the solvent can be further improved. The range of the content of the aforementioned silica particles in the 100% by weight of the aforementioned resin particles can be appropriately set by selecting the aforementioned lower limit and the aforementioned upper limit values.

[0136] Relative to 100 parts by weight of the resin particle body, the content of the silica particles is preferably 0.1 parts by weight or more, more preferably 0.5 parts by weight or more, further preferably 1.0 parts by weight or more, particularly preferably 3.0 parts by weight or more, and most preferably 5.0 parts by weight or more. Relative to 100 parts by weight of the resin particle body, the content of the silica particles is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, further preferably 15 parts by weight or less, and particularly preferably 10 parts by weight or less. When the content of the silica particles is at or above the aforementioned lower limit, low thermal expansion can be further effectively achieved. When the content of the silica particles is at or below the aforementioned upper limit, the dispersibility of the resin particles in the solvent can be further improved. The range of the silica particle content relative to 100 parts by weight of the resin particle body can be appropriately set by selecting the aforementioned lower limit and the aforementioned upper limit values.

[0137] <Other Ingredients>

[0138] The aforementioned resin particles and the resin particle body may contain other components as needed. Examples of such other components include: dispersants, preservatives, polymerization inhibitors, polymerization initiators, colorants, and surfactants. Only one of these other components may be used, or two or more may be used in combination.

[0139] The aforementioned resin particles may or may not contain surfactants. Examples of surfactants include: anionic surfactants such as carboxylates, sulfonates, sulfates, and phosphates; cationic surfactants such as amines and ammonium salts; amphoteric surfactants; ester / ether-type nonionic surfactants; and fluorinated surfactants such as perfluoroalkyl groups.

[0140] From the viewpoint of reducing environmental burden, the resin particles preferably contain a surfactant or do not contain a surfactant in a content of 1% by weight or less in 100% by weight of the resin particles. When the resin particles contain a surfactant, the content of the surfactant in 100% by weight of the resin particles is preferably 0.5% by weight or less, more preferably 0.1% by weight or less, and even more preferably 0.01% by weight or less. From the viewpoint of reducing environmental burden, the resin particles are more preferably free of surfactant, and the content of the surfactant in 100% by weight of the resin particles can be 0% by weight (not contained).

[0141] (Circuit board with insulating layer)

[0142] The aforementioned resin particles are suitable for obtaining a circuit board with an insulating layer (use of the aforementioned resin particles in a circuit board with an insulating layer). The aforementioned resin particles are suitable for use as a component of the insulating layer in a circuit board with an insulating layer (use of the aforementioned resin particles as a component of the insulating layer in a circuit board with an insulating layer). As an example of the aforementioned circuit board with an insulating layer, a circuit board having a circuit board and an insulating layer disposed on the surface of the circuit board, wherein the insulating layer comprises the aforementioned resin particles can be given.

[0143] In the aforementioned circuit board with an insulating layer, the insulating layer is preferably stacked on the surface of the circuit board where the circuit is disposed. In the aforementioned circuit board with an insulating layer, preferably a portion of the insulating layer is embedded between the circuits.

[0144] Specific examples of the aforementioned circuit boards with insulating layers include multilayer boards and multilayer printed circuit boards.

[0145] As an example of the aforementioned multilayer substrate, a multilayer substrate comprising a circuit substrate and an insulating layer laminated on the circuit substrate can be cited. The insulating layer of the aforementioned multilayer substrate contains the aforementioned resin particles. The insulating layer is preferably laminated on the surface of the circuit substrate where circuits (metal layers) are provided. Preferably, a portion of the insulating layer is embedded between the circuits. The aforementioned multilayer substrate preferably further comprises a copper plating layer laminated on the surface of the insulating layer.

[0146] As another example of the aforementioned multilayer substrate, a multilayer substrate comprising a circuit substrate, an insulating layer stacked on the surface of the circuit substrate, and copper foil stacked on the surface of the insulating layer opposite to the surface on which the circuit substrate is stacked.

[0147] As another example of the aforementioned multilayer substrate, a multilayer substrate comprising a circuit substrate and a plurality of insulating layers stacked on the surface of the circuit substrate can be cited. At least one of the plurality of insulating layers disposed on the circuit substrate contains the aforementioned resin particles. Preferably, the multilayer substrate further comprises a circuit stacked on the surface of at least one of the insulating layers.

[0148] The aforementioned multilayer printed circuit board includes, for example, a circuit board substrate, a plurality of insulating layers disposed on the surface of the circuit board substrate, and a metal layer disposed between the plurality of insulating layers. In the aforementioned multilayer printed circuit board, at least one of the insulating layers contains the aforementioned resin particles.

[0149] Figure 3 This is a schematic cross-sectional view of a multilayer printed circuit board using resin particles according to the first embodiment of the present invention.

[0150] exist Figure 3 In the multilayer printed circuit board 11 (circuit substrate with insulating layers) shown, a plurality of insulating layers 13-16 are stacked on the upper surface 12a of the circuit substrate 12. A metal layer 17 is formed in a portion of the upper surface 12a of the circuit substrate 12. Except for the insulating layer 16 located on the outer surface opposite to the circuit substrate 12, a portion of the upper surface of insulating layers 13-15 of the plurality of insulating layers 13-16 has a metal layer 17 formed therein. The metal layer 17 is a circuit. Metal layers 17 are disposed between the circuit substrate 12 and the insulating layers 13, and between each of the stacked insulating layers 13-16. The lower metal layer 17 and the upper metal layer 17 are interconnected by at least one of a via-hole connection (not shown) and a through-hole connection.

[0151] In the multilayer printed circuit board 11, insulating layers 13-16 contain resin particles 1. Furthermore, in the multilayer printed circuit board 11, good insulation reliability is provided between the upper metal layer 17 and the lower metal layer 17, which are not connected by vias or through-holes (not shown). In this embodiment, all insulating layers 13-16 contain resin particles 1, but at least one of the insulating layers 13-16 need to contain resin particles 1. Alternatively, resin particles such as resin particles 1A can be used instead of resin particles 1. It should be noted that in... Figure 3 In the diagram, resin particle 1 is shown in a simplified form.

[0152] Furthermore, the aforementioned resin particles can also be used in copper-clad laminates. As an example of such a copper-clad laminate, a copper-clad laminate comprising a copper foil and an insulating layer laminated on one side of the copper foil can be provided. The insulating layer of the aforementioned copper-clad laminate contains the aforementioned resin particles.

[0153] The present invention will now be specifically described by way of examples and comparative examples. The present invention is not limited to the examples described below.

[0154] The following materials have been prepared.

[0155] (The material that forms the main body of the resin particles)

[0156] Maleimide compound (1) (N-alkylbismaleimide compound, manufactured by Designer Molecules Inc., “BMI-689”)

[0157] Maleimide compound (2) (Designer Molecules Inc., “BMI-1400”)

[0158] Maleimide compound (3) (1,6-bismaleimide hexane)

[0159] Divinylbenzene (manufactured by NS Styrene Monomer, "DVB960")

[0160] Tetramethylolpropane trimethacrylate ("A-TMMT" manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0161] Silica particles (1) (ADMAFINE manufactured by ADMATECHS, average particle size 0.3 μm)

[0162] Silica particles (2) (ADMAFINE manufactured by ADMATECHS, average particle size 0.6 μm)

[0163] Silica particles (3) (ADMAFINE manufactured by ADMATECHS, average particle size 2 μm)

[0164] (Example 1)

[0165] Production of resin particles:

[0166] 49 parts by weight of divinylbenzene and 1 part by weight of silica particles (1) were added to 50 parts by weight of N-alkyl bismaleimide compound and stirred to obtain a monomer liquid in which silica particles were dispersed. Next, 1 part by weight of free radical polymerization initiator (tert-butyl peroxide, "PERBUTYLO" manufactured by Nippon Oil Co., Ltd.) was added to the obtained monomer liquid and stirred until homogeneous to obtain a monomer mixture. 200 parts by weight of a 1.0% aqueous solution of polyvinyl alcohol with a molecular weight of about 2000 dissolved in pure water was added to the reactor. The obtained monomer mixture was added to it and stirred until the monomer droplets reached the given particle size. Next, the monomer droplets were polymerized at 90°C for 9 hours to obtain particles. The obtained particles were washed three times each with hot water and acetone, and the resin particles were recovered by fractionation. In the obtained resin particles, in at least one silica particle, a portion of the silica particle was present inside the resin particle body and a portion of the silica particle was present on the surface (exposed) of the resin particle body.

[0167] Membrane fabrication:

[0168] Ten parts by weight of the obtained resin particles were dispersed in a mixture of 50 parts by weight of epoxy resin (bisphenol A type epoxy resin, "jER-828" manufactured by Mitsubishi Chemical Co., Ltd.), 50 parts by weight of butyl glycidyl ether, and 1 part by weight of cationic polymerization initiator ("San-Aid SI-60L" manufactured by Sanshin Chemical Industry Co., Ltd.) to obtain a composition. The obtained composition was coated onto a substrate to achieve a thickness of 100 μm, and heated at 100°C for 2 hours to obtain a film.

[0169] (Examples 2-15)

[0170] The types and contents (by weight%) of the main resin particles and the types and contents (by weight%) of the silica particles were changed as shown in Tables 1-3. Otherwise, the resin particles were prepared in the same manner as in Example 1. A film containing the resin particles was prepared in the same manner as in Example 1, except that the obtained resin particles were used.

[0171] (Comparative Examples 1-3)

[0172] The resin particles were prepared in the same manner as in Example 1, except that the type and content (by weight %) of the main resin particle material were changed as shown in Table 4, and silica particles were not used. A film containing the resin particles was prepared in the same manner as in Example 1, except that the obtained resin particles were used.

[0173] (Comparative Example 4)

[0174] Instead of using resin particles as the main body, silica particles (1) were prepared. Using the silica particles (1) instead of resin particles, a film containing silica particles was prepared in the same manner as in Example 1.

[0175] (Comparative Example 5)

[0176] Instead of using resin particles as the main body, silica particles (3) were prepared. Using the silica particles (3) instead of resin particles, a film containing silica particles was prepared in the same manner as in Example 1.

[0177] (evaluate)

[0178] (1) Average particle size of resin particles and average particle size of silica particles / average particle size of resin particles

[0179] For the obtained resin particles, approximately 100,000 particle sizes were measured using a particle size distribution measuring device (BECKMAN COULTER "Multisizer4"), and the average particle size was determined. Furthermore, the ratio of the average particle size of the silica particles to the average particle size of the resin particles (average particle size of silica particles / average particle size of resin particles) was calculated.

[0180] (2) Dielectric constant of resin particles (or silicon dioxide particles)

[0181] The dielectric constant of the obtained resin particles was calculated at 1 GHz using a dielectric constant measuring device (using a resonator for powder measurement manufactured by AET Corporation). It should be noted that for Comparative Examples 4 and 5, the dielectric constant of silica particles was evaluated instead of the resin particles.

[0182] (3) Dielectric loss tangent of resin particles (or silicon dioxide particles)

[0183] For the obtained resin particles, the dielectric loss tangent at 1 GHz was calculated using a dielectric constant measuring device (using a resonator for powder measurement manufactured by AET Corporation). It should be noted that for Comparative Examples 4 and 5, the dielectric loss tangent of silica particles was evaluated instead of resin particles.

[0184] (4) Thermal expansion coefficient of resin particles (or silica particles)

[0185] The thermal expansion coefficient of the obtained resin particles was evaluated at 50°C to 150°C as described below. It should be noted that for Comparative Examples 4 and 5, the thermal expansion coefficient of silica particles was evaluated instead of the resin particles. Using thermomechanical analysis (TMA), the resin particles (or silica particles) were held at 50°C for 5 minutes, and then heated from 50°C to 160°C at a heating rate of 5°C / min. The coefficient of linear expansion from 50°C (at the start of heating) to 150°C (at the point of reaching 150°C) was calculated. A TAINSTRUMENTS "TMA450" was used for the thermomechanical analysis (TMA).

[0186] (5) Dielectric constant of the film

[0187] The dielectric constant of the obtained film was calculated at 1 GHz using a dielectric constant measuring device (using a resonator for powder measurement manufactured by AET Corporation). The dielectric constant of the film was determined according to the following criteria.

[0188] [Criteria for determining the dielectric constant of a membrane]

[0189] ○○○: Dielectric constant is less than 2.50 F / m

[0190] ○○: Dielectric constant is above 2.50 F / m and below 2.70 F / m

[0191] ○: Dielectric constant is above 2.70 F / m and below 2.90 F / m

[0192] ×: Dielectric constant above 2.90 F / m

[0193] (6) Dielectric loss tangent of the film

[0194] For the obtained film, the dielectric loss tangent at 1 GHz was calculated using a dielectric constant measuring device (using a resonator for powder measurement manufactured by AET Corporation). The dielectric loss tangent of the film was determined according to the following criteria.

[0195] [Criteria for determining the dielectric loss tangent of a membrane]

[0196] ○○○: Dielectric loss tangent is less than 0.005

[0197] ○○: Dielectric loss tangent is greater than or equal to 0.005 and less than 0.008.

[0198] ○: Dielectric loss tangent is greater than or equal to 0.008 and less than 0.01.

[0199] ×: Dielectric loss tangent is 0.01 or higher.

[0200] (7) Thermal expansion coefficient of the membrane

[0201] The thermal expansion coefficient of the obtained membrane was evaluated from 50°C to 150°C as described below. Using thermomechanical analysis (TMA), the membrane was held at 50°C for 5 minutes, and then heated from 50°C to 160°C at a heating rate of 5°C / min. The coefficient of linear expansion from 50°C to 150°C was calculated. The TMA was performed using a TA Instruments "TMA450". The thermal expansion coefficient of the membrane was determined according to the following criteria.

[0202] [Criteria for determining the thermal expansion coefficient of membranes]

[0203] ○○○: Thermal expansion coefficient is less than 80ppm / ℃

[0204] ○○: Thermal expansion coefficient is above 80 ppm / ℃ and below 110 ppm / ℃

[0205] ○: Thermal expansion coefficient is above 110ppm / ℃ and below 150ppm / ℃

[0206] ×: Thermal expansion coefficient above 150ppm / ℃

[0207] The composition of the resin particles (or the composition of the silica particles) and the results are shown in Tables 1-4 below.

[0208]

[0209]

[0210]

[0211]

[0212] As shown in Table 4, the following results can be obtained. In Comparative Examples 1-3, which contain resin particles without silica particles, the low dielectric properties and / or low thermal expansion properties are poor. In addition, in Comparative Examples 4 and 5, which contain silica particles, the low dielectric properties are poor.

Claims

1. A resin particle comprising: a resin particle body, and a plurality of silica particles, the plurality of silica particles being present on a surface or inside of the resin particle body, the resin particle body being a polymer of a polymerizable component, the polymerizable component comprising a polymerizable compound having one or more maleimide groups.

2. The resin particle according to claim 1, wherein a particle diameter of the resin particle is 0.5 μm or more.

3. The resin particle according to claim 1 or 2, wherein a particle diameter of the silica particle is 1.0 μm or less.

4. The resin particle according to any one of claims 1 to 3, wherein a ratio of the particle diameter of the silica particle to the particle diameter of the resin particle is 0.001 or more and 0.5 or less.

5. The resin particle according to any one of claims 1 to 4, wherein a content of the silica particle is 0.1% by weight or more and 20% by weight or less in 100% by weight of the resin particle.

6. The resin particle according to any one of claims 1 to 5, wherein a content of the polymerizable compound having one or more maleimide groups is 10% by weight or more in 100% by weight of the polymerizable component.

7. The resin particle according to any one of claims 1 to 6, wherein the polymerizable component comprises a cross-linkable monomer different from the polymerizable compound having one or more maleimide groups.

8. The resin particle according to claim 7, wherein the cross-linkable monomer is divinylbenzene or a polymerizable compound having two or more (meth)acryloyl groups.

9. The resin particle according to claim 7 or 8, wherein a content of the cross-linkable monomer is 10% by weight or more in 100% by weight of the polymerizable component.

10. The resin particle according to any one of claims 1 to 9, wherein a thermal expansion rate of the resin particle at 50°C to 150°C is less than 150 ppm / °C.

11. The resin particle according to any one of claims 1 to 10, wherein a dielectric constant of the resin particle is 2.80 F / m or less, and a dielectric loss tangent of the resin particle is 0.01 or less.

12. The resin particle according to any one of claims 1 to 11, wherein in at least one of the plurality of silica particles, a part of the silica particle is present inside the resin particle body, and a part of the silica particle is present on a surface of the resin particle body.

13. A circuit board with an insulating layer, comprising: a circuit board, and an insulating layer disposed on a surface of the circuit board, the insulating layer comprising the resin particle according to any one of claims 1 to 12. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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