Method for producing composite material, composite material, and application product of composite material

Abstract

A method for producing a composite material according to one embodiment of the present disclosure produces a composite material having a dielectric loss tangent lower than the dielectric loss tangent of a metal organic structure including a plurality of metal ions. The method comprises: bringing a bonding polymer into contact with the metal organic structure; and combining the metal organic structure with the bonding polymer so that the bonding state of at least one of the plurality of metal ions changes.

Description

Composite material manufacturing method, composite material, and composite material application products

[0001] The present disclosure relates to a method for manufacturing a composite material, a composite material, and an application product of the composite material.

[0002] Patent Document 1 describes a resin composition for forming an insulating film, which contains a metal-organic framework and a curable resin. Non-Patent Documents 1 and 2 describe chemical modification of the surface of a metal-organic framework with polydopamine.

[0003] Japanese Patent Application Laid-Open No. 2018-80327

[0004] Qiao Tian, ​​Xiaohua Jia, Jin Yang, Sizhe Wang, Yong Li, Dan Shao, Haojie Song, Applied Surface Science, 2022, vol. 578, 152120Minchao Liu, Cheng Shang, Tiancong Zhao, Hongyue Yu, Yufang Kou, Zirui Lv, Mengmeng Hou, Fan Zhang, Qiaowei Li, Dongyuan Zhao, Xiaomin Li, Nature Communications, 2023, vol. 14, 1211

[0005] An object of the present disclosure is to provide a method for producing a composite material suitable for producing a composite material having a metal organic framework and realizing a reduced dielectric dissipation factor, and a composite material having a metal organic framework and realizing a reduced dielectric dissipation factor.

[0006] The method for producing a composite material according to the present disclosure is a method for producing a composite material having a dielectric loss tangent lower than that of a metal organic framework containing a plurality of metal ions, the method comprising: bringing the metal organic framework into contact with a binding polymer; and complexing the binding polymer with the metal organic framework so that a binding state of at least one metal ion among the plurality of metal ions is changed.

[0007] The composite material of the present disclosure comprises: a metal-organic framework including a plurality of metal ions; and a binding polymer, wherein the binding polymer is bound to at least one metal ion of the plurality of metal ions.

[0008] According to the present disclosure, it is possible to provide a method for producing a composite material suitable for producing a composite material having a metal organic framework in which a reduction in dielectric tangent is realized, and a composite material having a metal organic framework in which a reduction in dielectric tangent is realized.

[0009] FIG. 1 is a diagram showing a schematic configuration of a composite material according to Embodiment 1. FIG. 2 is a flowchart showing an example of a method for producing a composite material according to Embodiment 1. FIG. 3 is a diagram showing a schematic configuration of a resin composition according to Embodiment 4. FIG. 4 is a cross-sectional view of a resin-coated film according to Embodiment 6. FIG. 5 is a cross-sectional view of a resin-coated metal foil according to Embodiment 7. FIG. 6 is a cross-sectional view of a metal-clad laminate according to Embodiment 8. FIG. 7 is a cross-sectional view of a wiring board according to Embodiment 9. FIG. 8 is a cross-sectional view of an example of a circuit board according to Embodiment 12. FIG. 9A is a cross-sectional view of an example of a circuit board according to Modification 1. FIG. 9B is a partial enlarged view of FIG. 9A. FIG. 10 is a cross-sectional view of an example of a circuit board according to Modification 2. FIG. 11 is a cross-sectional view of an example of a circuit board according to Modification 3. FIG. 12 is a C1s XPS spectrum of the composite material according to Example 1. FIG. 13 is a C1s XPS spectrum of ZIF-8. FIG. 14 is a N1s XPS spectrum of the composite material according to Example 1. FIG. 15 is a N1s XPS spectrum of ZIF-8. Fig. 16 shows the O1s XPS spectrum of the composite material of Example 1. Fig. 17 shows the O1s XPS spectrum of ZIF-8. Fig. 18 shows TOF-SIMS data of the composite material of Example 2 and ZIF-8. Fig. 19 shows the infrared absorption spectrum of the composite material of Example 4 and the infrared absorption spectrum of ZIF-8. Fig. 20 shows the O1s XPS spectrum of the composite material of Example 4. Fig. 21 shows the O1s XPS spectrum of ZIF-8.

[0010] (Knowledge forming the basis of the present disclosure) In the electronics field, the level of performance required for electronic devices is increasing in preparation for the expansion of fifth-generation mobile communication systems (5G). For example, in order to achieve faster communication speeds than previous generations, 5G uses higher frequency bands. Therefore, electronic devices require electronic components that are compatible with high frequencies. In this specification, "high frequency" means, for example, a frequency of 1 MHz or higher.

[0011] Transmission loss in the transmission path of electronic components depends on frequency, increasing as the signal frequency increases. Transmission loss also depends on the relative dielectric constant and dielectric loss tangent of the insulating layer. Therefore, in order to reduce the transmission loss of high-frequency signals, materials such as substrate materials and sealing materials that constitute the insulating layers of electronic components are required to have low relative dielectric constants and low dielectric loss tangents.

[0012] Furthermore, with the increasing integration and miniaturization of electronic components, there is a demand for finer wiring and thinner insulating layers. In order to meet these demands, it is effective to reduce the relative dielectric constant of the insulating layer. In order to reduce the relative dielectric constant of the insulating layer, a filler with a low relative dielectric constant has been incorporated into the substrate material that constitutes the insulating layer.

[0013] Metal organic frameworks (MOFs) have attracted attention as fillers for insulating layers. MOFs, also known as porous coordination polymers (PCPs) or nanoporous metal complexes, are insulating materials. MOFs are crystalline porous materials composed of metal ions or metal clusters and crosslinking ligands. MOFs have a particularly low dielectric constant. MOFs have a low dielectric constant required for antenna substrates for communication base stations, and can meet, for example, a dielectric constant of 2.0 or less in high frequency bands ranging from GHz to THz. Therefore, MOFs have attracted attention as fillers for insulating layers in electronic components for various communication applications. For example, Patent Document 1 describes a resin composition for forming an insulating film containing MOF and a curable resin. MOFs have a negative thermal expansion coefficient, similar to inorganic fillers such as silica particles, which are commonly used as fillers for insulating layers. Furthermore, MOFs have a low dielectric constant due to their high porosity compared to other porous materials.

[0014] In recent years, miniaturization of wiring and thinning of insulating layers have led to a demand for smaller filler particle sizes. For example, if the particle size of the filler contained in the insulating layer is large, electrical noise due to variations in the dielectric constant between wiring may occur, and problems may arise in processability, strength, etc. It is known that the dielectric loss tangent of a material increases as the surface area of ​​the material increases. In other words, the increase in the dielectric loss tangent becomes more pronounced as the particle size of the filler decreases. An increase in the dielectric loss tangent can lead to problems such as increased transmission loss and heat generation.

[0015] The present inventors have conducted extensive research into reducing the dielectric loss tangent of metal-organic frameworks, and as a result have devised a method for controlling the dielectric loss tangent of a dielectric material and a composite material of the present disclosure.

[0016] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments.

[0017] First Embodiment Hereinafter, a first embodiment will be described with reference to FIGS. 1 and 2. FIG.

[0018] [Composite Material] Figure 1 is a diagram showing a schematic configuration of a composite material 10 in embodiment 1. The composite material 10 includes a metal-organic framework (hereinafter referred to as "MOF") 1 and a binding polymer 2. The MOF 1 contains a plurality of metal ions. The binding polymer 2 is bound to at least one of the plurality of metal ions contained in the MOF 1.

[0019] In the composite material 10, the binding polymer 2 binds to at least one of the metal ions contained in the MOF 1, thereby changing the binding state of the at least one metal ion. This can reduce the charge imbalance around the at least one metal ion. As a result, the dielectric loss tangent of the composite material 10 can be reduced.

[0020] The binding polymer 2 has a functional group that binds to the metal ion contained in the MOF 1. The functional group that binds to the metal ion includes, for example, a carbon atom, a nitrogen atom, an oxygen atom, a silicon atom, a phosphorus atom, or a sulfur atom. The binding polymer 2 may have at least one atom selected from the group consisting of a carbon atom, a nitrogen atom, an oxygen atom, a silicon atom, a phosphorus atom, and a sulfur atom.

[0021] Typically, within a MOF1, a metal ion or metal cluster has a certain number of available coordination sites, and to each of these available coordination sites is attached a bridging ligand.

[0022] On the other hand, on the surface of MOF1, among the coordination sites possessed by the metal ions or metal clusters, at least one site to which a bridging ligand is not bound exists. Such coordination sites to which a bridging ligand is not bound exhibit charge imbalance. When binding polymer 2 has a functional group that binds to metal ions, binding polymer 2 can be bound to the coordination sites exposed on the surface of MOF1 via this functional group. When binding polymer 2 binds to the unsaturated metal ions on the surface of MOF1, the binding state of the metal ions changes. Specifically, the coordination environment of the metal ions changes from a coordination unsaturated environment to a coordination saturated environment. This improves the symmetry of the coordination environment around the metal ions. By improving the symmetry of the coordination environment around the metal ions, charge imbalance around the metal ions can be reduced. As a result, a reduction in the dielectric loss tangent can be achieved in composite material 10.

[0023] The potential coordination sites on the surface of MOF1 may be terminated with a functional group different from the functional group terminating the cross-linking ligand present inside MOF1. Examples of such terminal functional groups include a hydroxyl group (—OH) and a carboxylate group (—COO). When binding polymer 2 has a hydrogen-bonding functional group, binding polymer 2 can be bonded to the terminal functional group exposed on the surface of MOF1 via a hydrogen bond. Examples of functional groups with hydrogen-bonding properties include functional groups having nitrogen atoms and / or oxygen atoms. This suppresses the mobility of polar functional groups present on the surface of MOF1. As a result, a reduction in the dielectric tangent of composite material 10 can be achieved.

[0024] Furthermore, when the binding polymer 2 has a terminal functional group capable of dehydration condensation with a hydroxyl group, the terminal functional group exposed on the surface of the MOF1 condenses with the dehydration condensation functional group present inside the binding polymer 2, forming a covalent bond. Examples of functional groups capable of dehydration condensation with a hydroxyl group include a hydroxyl group (-OH), a carboxyl group (-COOH), and a silanol group. This reduces the number of polar functional groups present on the surface of the MOF1. As a result, a reduction in the dielectric tangent of the composite material 10 can be achieved.

[0025] The binding polymer 2 preferably has two or more functional groups that bind to the metal ions of the MOF 1. The greater the number of functional groups that bind to the metal ions of the MOF 1, the greater the reduction in the dielectric loss tangent of the composite material 10.

[0026] In the composite material 10, the binding polymer 2 may be bonded to at least one of the plurality of metal ions contained in the MOF 1 by at least one bond selected from the group consisting of a coordinate bond, a hydrogen bond, and a covalent bond.

[0027] The binding of the binding polymer 2 to the MOF1 in the composite material 10 can be confirmed, for example, by comparing the infrared absorption spectrum of the composite material 10 with the infrared absorption spectrum of the MOF1. The binding of the binding polymer 2 to the MOF1 in the composite material 10 can also be confirmed, for example, by peak separation in the O1s XPS spectrum of the composite material 10. However, any method of confirmation is possible as long as it can be confirmed that the binding of the binding polymer 2 to the MOF1 in the composite material 10 is possible. For example, the binding of the binding polymer 2 to the MOF1 in the composite material 10 can be confirmed by time-of-flight secondary ion mass spectrometry (TOF-SIMS). In the present embodiment, when the binding polymer 2 is bound to the MOF1 and the dielectric loss tangent of the composite material 10 is lower than the dielectric loss tangent of the MOF1, it can be determined that the binding polymer 2 is bound to at least one of the metal ions contained in the MOF1 in the composite material 10.

[0028] In the composite material 10, the binding polymer 2 may be attached to the surface of the MOF 1. The binding polymer 2 may be attached to the surface of the MOF 1 by binding to a coordinating metal ion on the surface of the MOF 1. The binding polymer 2 may cover at least a portion of the surface of the MOF 1. The binding polymer 2 may cover the entire surface of the MOF 1, or may cover only a portion of the surface of the MOF 1.

[0029] In the composite material 10, the binding polymer 2 may be immobilized on the surface of the MOF1 by bonding. The binding polymer 2 may be immobilized on the surface of the MOF1 by bonding to a metal ion capable of coordinating on the surface of the MOF1. This can prevent water molecules, acids, and bases from reaching the MOF1 by the binding polymer 2. The acid is, for example, a proton or an oxonium ion. The base is, for example, a hydroxide ion. Therefore, the composite material 10 is particularly excellent in water resistance, base resistance, and acid resistance. That is, the composite material 10 has high chemical stability. Furthermore, since the binding polymer 2 is immobilized on the surface of the MOF1 by bonding, improved dispersibility in a predetermined solvent or resin can be expected. This improves the dispersibility of the composite material 10 in the resin composition, which can be expected to have effects such as an improved pot life of a slurry containing the resin composition, improved mechanical properties of the resin composition, and reduced variation in the dielectric properties of the resin composition. Furthermore, when the binding polymer 2 is fixed to the surface of MOF1 by bonding, it becomes possible to form a composite with other compounds without impairing the low dielectric tangent and chemical stability. For example, to obtain a resin composition containing the composite material 10 and other compounds, a process of dissolving them in a predetermined solvent for kneading or a mechanical dispersion process is required. When the binding polymer 2 is fixed to MOF1 by bonding, even after such a process, the resulting resin composition is prevented from having the binding polymer 2 on the surface of MOF1. Even when a resin composition containing MOF1, the binding polymer 2, and other compounds is formed in a single step, the resulting resin composition is prevented from having the binding polymer 2 on the surface of MOF1. In this way, by fixing the binding polymer 2 to the surface of MOF1 by bonding, the expected dielectric properties and / or chemical stability are exhibited even in the state of the resin composition.

[0030] MOF1 and binding polymer 2 will be described in more detail below.

[0031] [MOF] The MOF1 may comprise a zeolitic imidazolate framework (hereinafter referred to as "ZIF") and metal oxide clusters.

[0032] MOF1 may include a ZIF. ZIF is a general term for MOFs having a three-dimensional crystal structure similar to zeolites. ZIFs have a tetrahedral (Td) central metal ion and a bridging ligand containing imidazolate, and are constructed by a metal-imidazolate-metal coordination bond. Examples of the central metal ion include Zn 2+ , Co 2+ ZIF is useful because it has high thermal stability and high porosity. Examples of ZIF include ZIF-4, ZIF-7, ZIF-8, ZIF-12, ZIF-67, ZIF-90, and ZIF-412. ZIF is a material that is 2+ and a bridging ligand comprising an imidazolate.

[0033] The ZIF may be, for example, ZIF-8. ZIF-8 is a Zn II It is represented by the composition formula (2-MeIm)2, where 2-MeIm represents 2-methylimidazolate. ZIF-8 is a 2+ ZIF-8 has a sodalite-type crystal structure in which the ligand 2-methylimidazolate bridges the cations, demonstrating high thermal and chemical stability. ZIF-8 has a helium-equivalent porosity of 48% calculated using the RASPA package (https: / / iraspa.org / ) (see Anoopa Thomas, Rafiq Ahamed and Muthuramalingam Prakash, RSC Adv., 2020, vol. 10, 39160-39170), and is expected to have a low dielectric constant and low dielectric loss tangent.

[0034] MOF1 may contain metal oxide clusters, such as MO x (OH) 8-xExamples of such metal oxide clusters include those containing structural units represented by the following composition formula: M is a tetravalent Group 4 element. M is, for example, Zr, Hf, or Ce. The saturated coordination number is 12. M may also be Zr. That is, the metal oxide cluster may be a Zr oxide cluster. The crosslinkable ligands of such metal oxide clusters include, for example, a carboxylate group (-COO) or a hydroxyl group (-OH).

[0035] MOF1 may have Zr oxide clusters and bridging ligands containing carboxylate groups. Such zirconium-based MOFs are also called Zr-MOFs. In Zr-MOFs, the Zr oxide clusters are ZrO x (OH) 8-x (0≦x≦8) structural units. Two to twelve bridging ligands containing at least two carboxylate groups may be bonded to such a Zr oxide cluster. Zr-MOFs having the above structure possess high chemical and thermal stability, as well as high porosity, due to the strong Zr(IV)—O bonds. Therefore, Zr-MOFs are particularly useful. Examples of Zr-MOFs include UiO-66, UiO-67, UiO-68, NU-1000, NU-1103, MOF-808, PCN-224, DUT-52, BUT-30, and MIL-140.

[0036] The Zr-MOF may be, for example, NU-1000. NU-1000 is constructed from a Zr oxide cluster containing a structural unit represented by the compositional formula ZrO(OH) and a bridging ligand, 1,3,6,8-tetrakis(p-benzoic acid)pyrene. NU-1000 has the compositional formula ZrO(OH)(TBAPy). Here, TBAPy represents 1,3,6,8-tetrakis(p-benzoic acid)pyrene. NU-1000 has a porosity of 68%, calculated from the pore volume and crystal structure density, and is expected to have a low dielectric constant and a low dielectric loss tangent.

[0037] As MOF1, one selected from the group consisting of ZIF particles and Zr-MOF particles may be used. As MOF1, ZIF particles may be used. The shapes of the ZIF particles and Zr-MOF particles are not particularly limited. The shapes of the ZIF particles and Zr-MOF particles may be, for example, scale-like, spherical, oval-spherical, rod-like, etc., or may be amorphous. The average particle size of the ZIF particles and Zr-MOF particles is not particularly limited. The average particle size of the ZIF particles and Zr-MOF particles may be, for example, 0.01 μm or more and 100 μm or less, or 0.05 μm or more and 50 μm or less. In the present disclosure, the average particle size of the ZIF particles and Zr-MOF particles refers to the median diameter.

[0038] [Binding Polymer] The binding polymer 2 may contain oxygen atoms or nitrogen atoms. When the binding polymer 2 contains oxygen atoms or nitrogen atoms, it more readily binds to the coordinatable metal ions exposed on the surface of the MOF 1. This is expected to result in the composite material 10 having a lower dielectric tangent.

[0039] The binding polymer 2 may have a nitrogen-containing heterocycle. The nitrogen atom contained in the nitrogen-containing heterocycle has the ability to coordinate with the metal ions of MOF1 or to form hydrogen bonds with the hydroxyl groups terminated on the metal ions of MOF1, thereby further promoting binding to the coordinating metal ions exposed on the surface of MOF1. This is expected to result in a lower dielectric tangent for the composite material 10.

[0040] The binding polymer 2 may have at least one skeleton selected from the group consisting of an indole skeleton, an indoline skeleton, and a phenol skeleton.

[0041] The binding polymer 2 may have at least one skeleton selected from the group consisting of an indole skeleton and an indoline skeleton. The nitrogen atoms contained in the indole skeleton and the indoline skeleton have the ability to coordinate to metal ions contained in MOF1 or to form hydrogen bonds with hydroxyl groups terminated on metal ions contained in MOF1, thereby further promoting binding to the coordinating metal ions exposed on the surface of MOF1. This is expected to result in the composite material 10 having a lower dielectric tangent.

[0042] The binding polymer 2 may contain a phenol skeleton. The oxygen atoms contained in the phenol skeleton have the ability to coordinate with metal ions contained in MOF 1 or to form hydrogen bonds with hydroxyl groups terminated on metal ions contained in MOF 1, thereby further promoting binding to the coordinating metal ions exposed on the surface of MOF 1. This is expected to result in a lower dielectric tangent for the composite material 10.

[0043] The binding polymer 2 may contain at least one selected from the group consisting of polydopamine, polyvinylpyridine, and polyethylene glycol.

[0044] The binding polymer 2 may be polydopamine. The nitrogen and oxygen atoms contained in polydopamine have the ability to coordinate to metal ions in MOF1 or to form hydrogen bonds with hydroxyl groups terminated on metal ions in MOF1, thereby further promoting binding to metal ions capable of coordinating exposed on the surface of MOF1. This is expected to result in a lower dielectric loss tangent for the composite material 10. It is also known that nitrogen and oxygen atoms chelate to metal ions on the surface of MOF1 (see, for example, Non-Patent Document 2). When nitrogen and oxygen atoms chelate to metal ions, polydopamine can bond more firmly to metal ions on the surface of MOF1. In this case, the composite material 10 is expected to exhibit a low dielectric loss tangent and high thermal stability.

[0045] Polydopamine is a dopamine polymer and may have, for example, a repeating unit represented by the following formula (1): In the following formula (1), the indoline skeleton portion may be an indole skeleton: In the following formula (1), n ​​is an integer of 1 or more, particularly 2 or more.

[0046]

[0047] In this disclosure, even if some of the functional groups derived from dopamine in a polymer have changed due to bonding with other substances, the polymer is still considered to be a "polydopamine." One example of the change in functional groups is the loss of hydroxyl groups due to dehydration condensation between the hydroxyl groups of polydopamine and the hydroxyl groups of other substances.

[0048] The binding polymer 2 may be polyvinylpyridine. The multiple nitrogen atoms contained in the polyvinylpyridine have the ability to coordinate with metal ions in the MOF 1 or to form hydrogen bonds with hydroxyl groups terminated on the metal ions in the MOF 1, thereby further promoting binding to the coordinating metal ions exposed on the surface of the MOF 1. This is expected to result in the composite material 10 having a lower dielectric tangent.

[0049] The associative polymer 2 may contain an ether bond. The oxygen atom contained in the ether bond has the ability to coordinate with the metal ions of MOF1 or to form hydrogen bonds with the hydroxyl groups terminated on the metal ions of MOF1, thereby further promoting binding to the coordinating metal ions exposed on the surface of MOF1. This is expected to result in the composite material 10 having a lower dielectric tangent.

[0050] The binding polymer 2 may be polyethylene glycol. The oxygen atoms contained in the polyethylene glycol have the ability to coordinate with the metal ions of the MOF 1 or to form hydrogen bonds with the hydroxyl groups terminated on the metal ions of the MOF 1, thereby further promoting binding to the coordinating metal ions exposed on the surface of the MOF 1. This is expected to result in the composite material 10 having a lower dielectric tangent.

[0051] The binding polymer 2 may include a silicon-containing polymer that includes silicon atoms. The binding polymer 2 may be a silicon-containing polymer.

[0052] The silicon-containing polymer may have a main chain containing at least one unit selected from the group consisting of styrene units, butadiene units, ethylene units, cycloolefin units, and fluorine-containing olefin units. Compared to silicon-containing low molecular weight compounds such as alkylsilanes, silicon-containing polymers can prevent water molecules, acids, and bases from reaching MOF1. The acid is, for example, a proton or an oxonium ion. The base is, for example, a hydroxide ion. Therefore, composite material 10 in which a silicon-containing polymer is bonded to the surface of MOF1 has particularly excellent base and acid resistance. In other words, such composite material 10 has high chemical stability. Furthermore, due to its structural characteristics, silicon-containing polymers can suppress adsorption of moisture from the atmosphere. In addition, silicon-containing polymers are less likely to evaporate when heated than silicon-containing low molecular weight compounds such as alkylsilanes. Therefore, silicon-containing polymers are also useful from the perspective of heat resistance.

[0053] The silicon-containing polymer may include, in addition to the main chain, a side chain branching from the main chain. The silicon-containing polymer may include a plurality of side chains. The main chain may include a first main chain composed of carbon atoms bonded to each other. The silicon-containing polymer may include, together with the first main chain, a side chain containing a silicon atom.

[0054] The silicon-containing polymer may include a first side chain comprising a silicon atom and an oxygen atom. The silicon-containing polymer may be bonded to the surface of MOF1 via the silicon atom and the oxygen atom. More specifically, the silicon-containing polymer may include an oxygen atom bonded to the silicon atom and to MOF1.

[0055] The manner in which the silicon-containing polymer binds to the surface of MOF1 via silicon and oxygen atoms is assumed to be as follows. As described above, typically, within MOF1, a metal ion or metal cluster has a predetermined number of potential coordination sites, and a bridging ligand is bonded to each of these potential coordination sites. Meanwhile, on the surface of MOF1, at least one potential coordination site of the metal ion or metal cluster remains to which no bridging ligand is bonded. The potential coordination site exposed on the surface of MOF1 is Lewis acidic and can bond, for example, to an oxygen atom having Lewis basicity. In this case, an M-O bond is expected to exist between the surface of MOF1 and the oxygen atom. M represents a metal atom. In this case, in composite material 10, at least one M-O bond is formed between the silicon-containing polymer and MOF1, thereby binding the silicon-containing polymer to the surface of MOF1.

[0056] It is also known that some of the coordination sites exposed on the surface of MOF1 are bonded to hydroxyl groups (-OH) (e.g., Fangyuan Tian, ​​Andrew M. Cerro, Amber M. Mosier, Hannah K. Wayment-Steele, Ryan S. Shine, Aileen Park, Elizabeth R. Webster, Lewis E. Johnson, Malkiat S. Johal and Lauren Benz, J. Phys. Chem., 2014, vol. 118, 14449-14456, and Dong Yang, Melike Babucci, William H. Casey, and Bruce C. Gates, ACS. Cent. Sci., 2020, vol. 6, 1523-1533). In this case, M-OH bonds are expected to exist on the surface of MOF1. It is known that M-OH bonds form M-O-Si bonds, for example, by silane coupling reactions. In this case, it is expected that in composite material 10, at least one M-O-Si bond is formed between the silicon-containing polymer and MOF1, thereby bonding the silicon-containing polymer to the surface of MOF1. It is also expected that the M-OH bond on the surface of MOF1 forms an M-OH-O hydrogen bond with an oxygen atom of the silicon-containing polymer. Thus, it is expected that in composite material 10, at least one M-OH-O bond is formed between the silicon-containing polymer and MOF1, thereby bonding the silicon-containing polymer to the surface of MOF1.

[0057] For example, when MOF1 is ZIF-8, it is expected that there are Zn coordination sites or Zn-OH bonds on the surface of ZIF-8. Therefore, in this case, it is expected that at least one Zn-O bond, Zn-O-Si bond, or Zn-OH-H bond is formed between the silicon-containing polymer and ZIF-8, thereby binding the silicon-containing polymer to the surface of ZIF-8.

[0058] Furthermore, in the composite material 10, when the silicon-containing polymer is immobilized on the surface of the MOF 1 by bonding, the surface of the MOF 1 is constantly covered with the low-polarity polymer, which is expected to improve the dispersibility of the composite material 10 in a specific solvent. In particular, the dispersibility of the composite material 10 is expected to improve in a non-polar solvent. An example of the non-polar solvent is toluene.

[0059] The silicon-containing polymer is —SiR 3-n (OX) n Here, n is an integer of 1 to 3, and X represents a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a bonding moiety bonded to MOF1, or a bonding moiety bonded to a silicon atom other than the silicon atom of the functional group. The bonding moiety X can also be represented by a single bond (-). The hydrocarbon group having 1 to 10 carbon atoms is, for example, an alkyl group having 1 to 10 carbon atoms, particularly 1 to 3 carbon atoms. At least one of the X's is a bonding moiety bonded to MOF1. R represents a hydrocarbon group having 1 to 10 carbon atoms. A silicon-containing polymer having such a structure is immobilized on the surface of MOF1 via an M-O-Si bond. Therefore, the surface of MOF1 is more densely covered with the silicon-containing polymer, thereby further reducing the dielectric tangent of the composite material 10 and improving its chemical stability.

[0060] -SiR 3-n (OX) n In the functional group represented by the formula: R may be an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0061] The alkyl group having 1 to 10 carbon atoms may have any of a linear, cyclic, or branched structure. Examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, an α-naphthyl group, and a β-naphthyl group.

[0062] The silicon-containing polymer is —SiR 3-n (OX) n and X contains a bond bonded to another silicon atom, the silicon-containing polymer contains siloxane units represented by Si—O—Si. The silicon-containing polymer may also contain a second main chain composed of siloxane units. A silicon-containing polymer having such a structure may have a network structure in which siloxane units (Si—O—Si) are spread out in a mesh-like pattern.

[0063] The silicon-containing polymer may include a second side chain containing at least one bond selected from the group consisting of a carbon-carbon double bond and a carbon-carbon triple bond. With such a structure, the carbon-carbon double bond or carbon-carbon triple bond reacts with a reactive residue of the resin contained in the insulating layer to form a bond, thereby improving the adhesion between the composite material 10 and the resin. This reduces the thermal resistance at the interface between the composite material 10 and the resin, improving the thermal conductivity of the insulating layer. Consequently, the heat dissipation properties of the wiring board are improved. Examples of groups containing a carbon-carbon double bond include a vinyl group, a methallyl group, and an acryloyl group. The silicon-containing polymer may contain one or more groups selected from these. From the viewpoint of easy reactivity, the group containing a carbon-carbon double bond is preferably a vinyl group. Examples of reactive residues of the resin contained in the insulating layer include a vinyl group, a methallyl group, and an acryloyl group. Examples of groups containing a carbon-carbon triple bond include an ethynyl group and a propargyl group. The silicon-containing polymer may contain one or more selected from these. Examples of reactive residues of the resin contained in the insulating layer include ethynyl groups and propargyl groups. At least one bond selected from the group consisting of a carbon-carbon double bond and a carbon-carbon triple bond may be located at the end of the second side chain. The second side chain may consist solely of a chain structure.

[0064] From the viewpoint of avoiding deterioration due to oxidation, it is desirable that the silicon-containing polymer contain a small amount of carbon-carbon double bonds and carbon-carbon triple bonds.

[0065] The silicon-containing polymer may further include a side chain other than the first side chain and the second side chain. The side chain other than the first side chain and the second side chain may have, for example, a cyclic structure. The cyclic structure of the side chain may be, for example, an aryl group.

[0066] The backbone of the silicon-containing polymer may contain butadiene units.

[0067] The backbone of the silicon-containing polymer may comprise a copolymer containing styrene units and butadiene units.

[0068] The silicon-containing polymer may be represented by the following formula (2) which includes a plurality of repeating units:

[0069]

[0070] In the above formula (2), a and d represent numbers equal to or greater than 0, b and c represent numbers greater than 0, and R 1 From R 5 are each independently a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, or —CH3, provided that the order of the multiple repeating units is arbitrary. 3-n (OX) n The functional group represented by is as explained above. In the part d of the above formula (2), the bond represented by the wavy line means either trans or cis, or a mixture of both.

[0071] In the above formula (2), the silicon-containing polymer may satisfy 0≦a≦500, 1≦b≦500, 1≦c≦500, and 0≦d≦500, or may satisfy 5≦a≦300, 5≦b≦300, 1≦c≦100, and 5≦d≦300.

[0072] In the above formula (2), the silicon-containing polymer may satisfy 5≦a≦100, 5≦b≦100, 1≦c≦80, and 5≦d≦100, or may satisfy 5≦a≦20, 5≦b≦50, 1≦c≦60, and 5≦d≦40.

[0073] In the above formula (2), c represents the repeating number of butadiene units having silicon and oxygen in their side chains. (b + c + d) represents the sum of the butadiene units having repeating number b, the butadiene units having repeating number c, and the butadiene units having repeating number d. The silicon-containing polymer may satisfy 0.15≦c / (b + c + d) in the above formula (2). In other words, the value calculated by 100×{c / (b + c + d)} in the above formula (2) may be 15% or more. This configuration further improves the chemical stability of the composite material 10. In the above formula (2), the value calculated by 100×{c / (b + c + d)} may be 17% or more. The upper limit of the value calculated by 100×{c / (b + c + d)} is, for example, 80%. However, the value calculated by 100×{c / (b+c+d)} is not particularly limited as long as it is within a range in which the desired chemical stability and dielectric properties can be exhibited.

[0074] The silicon-containing polymer represented by the above formula (2) is represented by the following formula (3) before being bonded to MOF1.

[0075]

[0076] In the above formula (3), R 6 and R 7 are each independently a hydrocarbon group having 1 to 10 carbon atoms. m is an integer of 1 to 3. a and d are numbers of 0 or more, and b and c are numbers greater than 0.

[0077] In the above formula (3), R 6 and R 7 may each independently represent an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms.

[0078] The alkyl group having 1 to 10 carbon atoms and the aryl group having 6 to 10 carbon atoms are represented by —SiR 3-n (OX) n However, in the above formula (2), as the alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 5 carbon atoms is more preferable, and an alkyl group having 1 to 3 carbon atoms is even more preferable. 6and R 7 are each independently preferably a straight-chain alkyl group, more preferably a methyl group or an ethyl group.

[0079] The silicon-containing polymer represented by formula (3) can be obtained via the reaction shown in the following scheme. Specifically, a styrene-butadiene copolymer represented by formula (4) and an organosilicon compound represented by formula (5) are hydrosilylated in the presence of a platinum compound-containing catalyst, preferably in the presence of a platinum compound-containing catalyst and a co-catalyst. This allows the silicon-containing polymer represented by formula (3) to be obtained.

[0080]

[0081] The styrene-butadiene copolymer represented by the formula (4) can be synthesized by a known method such as emulsion polymerization or solution polymerization using butadiene and styrene as raw material monomers. The styrene-butadiene copolymer represented by the formula (4) can also be obtained as a commercially available product. Examples of commercially available products include Ricon 100, Ricon 181, and Ricon 184 (all manufactured by Cray Valley Chemical Industry Co., Ltd.), L-SBR-820 and L-SBR-841 (all manufactured by Kuraray Co., Ltd.), and 1,2-SBS (all manufactured by Nippon Soda Co., Ltd.).

[0082] Examples of the organosilicon compound represented by the above formula (5) include trimethoxysilane, methyldimethoxysilane, dimethylmethoxysilane, triethoxysilane, methyldiethoxysilane, and dimethylethoxysilane.

[0083] The value of c is maintained before and after the silicon-containing polymer is bonded to the surface of MOF1. That is, the value of c in the above formula (3) is equal to the value of c in the above formula (2). Therefore, the silylation rate calculated by 100 × {c / (b + c + d)} in the above formula (3) can be regarded as the silylation rate calculated by 100 × {c / (b + c + d)} in the above formula (2).

[0084] The composite material 10 may further include molecules or other polymers other than the binding polymer 2. In other words, the binding polymer 2 may be modified by molecules or other polymers other than the binding polymer 2. For example, the composite material 10 may include polydopamine as the binding polymer 2 and a silicon-containing polymer as the other polymer. In this case, the silicon-containing polymer may be bonded to the polydopamine via a silicon atom and an oxygen atom.

[0085] [Manufacturing Method of Composite Material] Next, a description will be given of a manufacturing method of the above-described composite material 10. In the following, elements common to the above-described composite material 10 will be denoted by the same reference numerals and description thereof will be omitted.

[0086] 2 is a flowchart showing an example of a method for producing composite material 10 according to the first embodiment. The method for producing composite material 10 is a method for producing a composite material having a dielectric loss tangent lower than that of MOF1, and includes the steps of bringing binding polymer 2 into contact with MOF1 (step ST1) and complexing binding polymer 2 with MOF1 so as to change the bonding state of at least one metal ion among a plurality of metal ions contained in MOF1 (step ST2). This method makes it possible to produce composite material 10 including MOF1, in which the dielectric loss tangent is reduced due to the change in the coordination environment of the metal ions.

[0087] Step ST2 may include compounding the MOF 1 with the binding polymer 2 so as to change the binding state of at least one metal ion present on the surface of the MOF 1. This configuration facilitates the production of the composite material 10 that achieves a reduced dielectric tangent. By binding the binding polymer 2 to at least one metal ion, the binding state of at least one metal ion among the multiple metal ions contained in the MOF 1 may be changed.

[0088] In step ST2, the binding state of at least one metal ion capable of coordinating and exposed on the surface of MOF1 may be changed by binding a binding polymer 2 to this metal ion.

[0089] [Method for controlling the dielectric loss tangent of a dielectric material] Next, a method for controlling the dielectric loss tangent of a dielectric material in embodiment 1 will be described. In the following, elements common to the composite material 10 described above will be denoted by the same reference numerals and description thereof will be omitted.

[0090] In a method for controlling the dielectric loss tangent of a dielectric material, the dielectric material includes MOF1, and the control method includes (step S1) compounding MOF1 with another material so as to change the bonding state of at least one metal ion among a plurality of metal ions contained in MOF1, thereby reducing the dielectric loss tangent of the dielectric material. The control method in embodiment 1 is suitable for reducing the dielectric loss tangent of a dielectric material including MOF1.

[0091] In the present disclosure, the term "dielectric material" is a concept that includes both MOF1 before and after the composite. Note that the composite material 10 described above corresponds to the dielectric material after the dielectric loss tangent has been reduced by the control method.

[0092] The other material includes a binding polymer 2. In step S1, complexing the other material may include binding the binding polymer 2 to at least one metal ion among the plurality of metal ions contained in the MOF 1. By binding the binding polymer 2 to the at least one metal ion, the binding state of the at least one metal ion among the plurality of metal ions contained in the MOF 1 may be changed.

[0093] In step S1, at least one metal ion may be present on the surface of MOF 1. The binding state of the at least one metal ion capable of coordinating and exposed on the surface of MOF 1 may be changed by binding binding polymer 2 to the metal ion.

[0094] Second Embodiment An insulating material according to a second embodiment contains the composite material 10 of the first embodiment.

[0095] The insulating material of the second embodiment can be used as an insulating material for electronic components. The insulating material for electronic components is, for example, a filler for forming an insulating layer. When used as an insulating material for electronic components, the insulating material of the second embodiment can improve chemical stability while suppressing increases in the dielectric constant and dielectric loss tangent.

[0096] Third Embodiment A filler according to a third embodiment contains the composite material 10 of the first embodiment.

[0097] The filler in the third embodiment may be a filler for forming an insulating layer. In the present disclosure, the filler for forming an insulating layer refers to a filler that is mixed with a resin component and used as an insulating material for a wiring board or a sealing material for an IC chip. When used as a filler for forming an insulating layer, the filler in the third embodiment can improve chemical stability while suppressing increases in the relative dielectric constant and dielectric loss tangent.

[0098] The filler in the third embodiment can be produced by, for example, kneading the composite material 10 in the first embodiment with an epoxy resin or a silicone-based resin, or a non-silicone acrylic resin or a ceramic-based resin.

[0099] 3 is a diagram showing a schematic configuration of a resin composition 20 according to an embodiment 4. The resin composition 20 contains, for example, a filler 22 and a curable resin 24.

[0100] The filler 22 includes the composite material 10 of embodiment 1. According to this embodiment, it is possible to provide a resin composition 20 that exhibits a low dielectric tangent and excellent heat resistance. As the filler 22, only the composite material 10 may be used, or other filler materials such as silica particles may be used in combination with the composite material 10.

[0101] Examples of the curable resin 24 include epoxy resin, cyanate ester compound, maleimide compound, phenol resin, acrylic resin, polyamide resin, polyamideimide resin, thermosetting polyimide resin, polyphenylene ether resin, etc. As the curable resin 24, one or a combination of two or more selected from these can be used.

[0102] The resin composition 20 may contain other components. Examples of the other components include a curing agent, a flame retardant, an ultraviolet absorber, an antioxidant, a reaction initiator, a silane coupling agent, a fluorescent brightening agent, a photosensitizer, a dye, a pigment, a thickener, a lubricant, an antifoaming agent, a dispersant, a leveling agent, a glossing agent, an antistatic agent, a polymerization inhibitor, and an organic solvent. As the other components, one or a combination of two or more selected from these may be used as needed.

[0103] (Embodiment 5) The prepreg in embodiment 5 comprises, for example, the resin composition 20 of embodiment 4 shown in FIG. 3 or a semi-cured product thereof. The prepreg may further comprise a fibrous base material. The fibrous base material is present in the matrix of the resin composition 20 or a semi-cured product thereof. In other words, the prepreg may be a composite material of the resin composition 20 and the fibrous base material. According to this embodiment, a prepreg suitable for high-frequency wiring boards can be provided.

[0104] In this embodiment, the semi-cured product refers to a material in a partially cured state to the extent that the resin composition 20 can be further cured. In other words, the semi-cured product is a material in a semi-cured state of the resin composition 20. For example, when the resin composition 20 is heated, its viscosity gradually decreases. If the heating is continued, curing then begins and the viscosity gradually increases. In such a case, the semi-cured state refers to the state of the resin composition 20 from the point when the viscosity starts to increase until the point when it is completely cured.

[0105] The fibrous substrate may be any known material used in various types of laminates for electrical insulating materials, such as glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper.

[0106] The resin composition 20 is impregnated into the fibrous base material by a process such as immersion or coating. The fibrous base material impregnated with the resin composition 20 is heated under predetermined heating conditions to obtain the prepreg in the uncured or semi-cured state according to the present embodiment.

[0107] Sixth Embodiment Fig. 4 is a cross-sectional view of a resin-coated film 30 in a sixth embodiment. The resin-coated film 30 comprises a resin layer 32 containing the resin composition 20 or a semi-cured product thereof, and a support film 34. According to this embodiment, a resin-coated film 30 suitable for an insulating layer can be provided. The resin layer 32 is supported by the support film 34. In the example of Fig. 4, the support film 34 is disposed on the surface of the resin layer 32. However, another layer such as an adhesive layer may be provided between the resin layer 32 and the support film 34.

[0108] The resin layer 32 includes the resin composition 20 of the fourth embodiment shown in FIG. 3 or a semi-cured product thereof. The resin layer 32 may or may not include a fibrous base material. The fibrous base material may be the same material as the fibrous base material described for the prepreg. The resin layer 32 hardens and changes into an insulating layer. An example of such an insulating layer is the insulating layer of a wiring board.

[0109] Any support film used for a resin-coated film can be used without limitation as the support film 34. Examples of the support film 34 include resin films such as polyester films and polyethylene terephthalate films.

[0110] Seventh Embodiment Fig. 5 is a cross-sectional view of a resin-coated metal foil 40 according to a seventh embodiment. The resin-coated metal foil 40 comprises a resin layer 42 containing the resin composition 20 or a semi-cured product thereof, and a metal foil 44. The resin layer 42 is supported by the metal foil 44. This embodiment can provide a resin-coated metal foil 40 suitable for electronic circuit components such as wiring boards. In the example of Fig. 5, the metal foil 44 is disposed on the surface of the resin layer 42. However, another layer, such as an adhesive layer, may be disposed between the resin layer 42 and the metal foil 44.

[0111] The resin layer 42 includes the resin composition 20 of the fourth embodiment shown in FIG. 3 or a semi-cured product thereof. The resin layer 42 may or may not include a fibrous base material. The fibrous base material may be the same material as the fibrous base material described for the prepreg. The resin layer 42 hardens and changes into an insulating layer. An example of such an insulating layer is the insulating layer of a wiring board.

[0112] There are no limitations on the metal foil 44. Metal foils with resins and metal foils used in metal-clad laminates can be used. Examples of metal foils include copper foil and aluminum foil.

[0113] Eighth Embodiment Fig. 6 is a cross-sectional view of a metal-clad laminate 50 according to an eighth embodiment. The metal-clad laminate 50 includes an insulating layer 52 and at least one metal foil 54. According to this embodiment, a metal-clad laminate 50 suitable for wiring boards can be provided. The insulating layer 52 includes a cured product of the resin composition 20 of the fourth embodiment shown in Fig. 3 or a cured product of the prepreg of the fifth embodiment. The metal foil 54 is disposed on the surface of the insulating layer 52. In this embodiment, a metal foil 54 is disposed on each of the front and back surfaces of the insulating layer 52.

[0114] The metal-clad laminate 50 is typically manufactured using the prepreg of embodiment 5. For example, 1 to 20 prepregs are stacked to form a laminate. Metal foil 54 is placed on one or both sides of the prepreg laminate, and the metal-clad laminate 50 is obtained by heating and pressing. Examples of the metal foil 54 include copper foil and aluminum foil.

[0115] The molding conditions for producing the metal-clad laminate 50 may be, for example, the molding conditions for producing laminates and multilayer boards for electrical insulating materials.

[0116] (Embodiment 9) Fig. 7 is a cross-sectional view of a wiring board 60 in embodiment 9. The wiring board 60 includes an insulating layer 62 and wiring 64. According to this embodiment, it is possible to provide a wiring board 60 suitable for high frequencies. The insulating layer 62 includes a cured product of the resin composition 20 of embodiment 4 shown in Fig. 3 or a cured product of the prepreg of embodiment 5. The wiring 64 is supported by the insulating layer 62. More specifically, the wiring 64 is disposed on the insulating layer 62. The wiring 64 can be formed by partially removing the metal foil.

[0117] 6 is patterned by etching or other methods to obtain a wiring board 60 having wiring 64 forming a circuit on the surface of an insulating layer 62. That is, the wiring board 60 is obtained by partially removing the metal foil 54 on the surface of the metal-clad laminate 50 so that a circuit is formed.

[0118] A new laminate may be formed by laminating the prepreg of embodiment 5 on at least one surface of wiring board 60 and then applying heat and pressure. A multilayer wiring board can be obtained by patterning the metal foil on the surface of the obtained laminate to form wiring.

[0119] Tenth Embodiment A sealing material for circuit boards in a tenth embodiment includes the resin composition 20 of the fourth embodiment.

[0120] The sealing material for circuit boards in the tenth embodiment can be used, for example, as a sealing material for protecting semiconductor chips from heat, moisture, dust, etc. When used as a sealing material for protecting semiconductor chips from heat, moisture, dust, etc., the sealing material for circuit boards in the tenth embodiment can improve chemical stability while suppressing increases in the relative dielectric constant and dielectric loss tangent.

[0121] Eleventh Embodiment An adhesive material for a circuit board in an eleventh embodiment includes the resin composition 20 of the fourth embodiment or a semi-cured product thereof.

[0122] The adhesive material for a circuit board in the eleventh embodiment can be used, for example, as an adhesive material for protecting a semiconductor chip from heat, moisture, dust, etc. When used as an adhesive material for protecting a semiconductor chip from heat, moisture, dust, etc., the adhesive material for a circuit board in the eleventh embodiment can improve chemical stability while suppressing increases in the relative dielectric constant and the dielectric loss tangent.

[0123] (Embodiment 12) A circuit board according to embodiment 12 includes an insulating layer containing a cured product of resin composition 20 according to embodiment 4 or a cured product of the prepreg according to embodiment 5. The circuit board according to embodiment 12 can improve chemical stability while suppressing increases in the relative dielectric constant and dielectric loss tangent, and can provide a circuit board suitable for high frequencies.

[0124] FIG. 8 is a cross-sectional view showing an example of a circuit board according to the twelfth embodiment. The circuit board 1000 of FIG. 8 includes a wiring board 100, an antenna board 200, and a radio-frequency integrated circuit (RFIC) 300. The antenna board 200 is stacked on the wiring board 100. The RFIC 300 processes high-frequency signals. The circuit board 1000 can transmit or send high-frequency signals output by the RFIC 300 from the antenna board 200, and can process high-frequency signals received by the antenna board 200 using the RFIC 300. Note that the circuit board 1000 in which an antenna and an RFIC are integrated as shown in FIG. 8 is sometimes called an antenna-in-package (AiP). The circuit board 1000 is mounted on a motherboard 500 as a base for use.

[0125] The circuit board 1000 is typically an electronic circuit board that is mounted on a motherboard in a computer and on which an antenna element can be arranged. The circuit board 1000 may be a high-frequency circuit board that is intended to use high-frequency signals.

[0126] As shown in FIG. 8 , the wiring board 100 may include a core layer 101 and a wiring stack 102 stacked on a first surface 101 a of the core layer 101. The core layer 101 is an insulating layer. The wiring stack 102 is disposed between the core layer 101 and the antenna substrate 200. The wiring stack 102 includes a plurality of conductor layers 121. One or more insulating layers 122 are provided between the plurality of conductor layers 121. The wiring stack 102 may be a build-up layer formed by alternately stacking the conductor layers 121 and the insulating layers 122 on the first surface 101 a of the core layer 101, i.e., by build-up. The core layer 101 includes conductor layers 111 on the first surface 101 a and the second surface 101 b, and through holes 112 electrically connecting the first surface 101 a and the second surface 101 b. The conductor layer 121 and the conductor layer 111 are made of copper foil, and the inner surface of the through hole 112 is plated with copper.

[0127] The antenna substrate 200 includes an insulating layer 201 and an antenna element 202. The antenna element 202 is formed of copper foil. The antenna element 202 is provided on a first surface 201a of the insulating layer 201. The first surface 201a is the surface opposite to a second surface 201b of the insulating layer 201, which is the surface of the insulating layer 201 facing the wiring stack 102. The antenna element 202 is electrically connected to the wiring substrate 100, for example, through a via hole (not shown) that penetrates the insulating layer 201 in the thickness direction. The antenna element 202 may be electrically connected to the wiring substrate 100 through a connecting portion (not shown). For example, solder, conductive resin, or the like may be used as the connecting portion. As shown in FIG. 8 , the antenna substrate 200 may include a plurality of antenna elements 202. The plurality of antenna elements 202 may form an array.

[0128] 8, the RFIC 300 is embedded in the core layer 101 and is electrically connected to the antenna substrate 200 via the conductor layer 121 of the wiring stack portion 102. However, the arrangement of the RFIC 300 is not limited to the example shown in FIG.

[0129] 8, the circuit board 1000 may be connected to the upper surface 500a of the motherboard 500 via a connection portion 400 provided on the second surface 101b of the core layer 101. The connection portion 400 electrically connects the circuit board 1000 and the motherboard 500, and also fixes the circuit board 1000 to the motherboard 500. The connection portion 400 may be made of, for example, solder, conductive resin, or the like.

[0130] Although not shown in the figure, the circuit board 1000 may further include a bonding film that bonds the core layer 101 and the wiring stack 102 together, and / or a bonding film that bonds the wiring stack 102 and the insulating layer 201 of the antenna substrate 200.

[0131] An insulating layer containing the cured product of the resin composition 20 of embodiment 4 or the cured product of the prepreg of embodiment 5 can be applied to any of the core layer 101, the insulating layer 122 of the wiring stack 102, the insulating layer 201 of the antenna substrate 200, and the bonding film.

[0132] 8, the circuit board 1000 may further include an antenna element 202 capable of transmitting high-frequency signals. The circuit board 1000 may have a plurality of antenna elements 202. The plurality of antenna elements 202 may form an array. A circuit board having such a configuration is used for an antenna that is expected to use high-frequency signals.

[0133] The circuit board in embodiment 12 is not limited to the circuit board 1000 shown in FIG. 8 . An insulating layer containing a cured product of the resin composition 20 of embodiment 4 or a cured product of the prepreg of embodiment 5 can also be used, for example, as an insulating layer of a multilayer printed wiring board. Furthermore, an insulating layer containing a cured product of the resin composition 20 of embodiment 4 or a cured product of the prepreg of embodiment 5 can be used as an insulating layer for forming wiring portions by plating, for example, as an insulating layer of a multilayer printed wiring board in which wiring portions are formed by plating. Furthermore, an insulating layer containing a cured product of the resin composition 20 of embodiment 4 or a cured product of the prepreg of embodiment 5 can be used as an insulating layer for forming a build-up layer of a multilayer printed wiring board.

[0134] Modified examples of the circuit board will be described below. In the following, elements common to the circuit board 1000 shown in FIG. 8 will be denoted by the same reference numerals and description thereof will be omitted.

[0135] (Modification 1) Fig. 9A is a cross-sectional view showing an example of a circuit board 2000 in Modification 1. Fig. 9B is an enlarged view of portion IXB in Fig. 9A. Circuit board 2000 has an insulating layer including a cured product of resin composition 20 of embodiment 4 or a cured product of the prepreg of embodiment 5.

[0136] The circuit board 2000 includes a package substrate 105 and a semiconductor chip 305 disposed on the package substrate 105. The semiconductor chip 305 includes active elements such as transistors and diodes. The active elements of the semiconductor chip 305 are connected to the circuitry of the package substrate 105. The package substrate 105 may include a core layer 151 and a pair of buildup layers 152 that sandwich the core layer 151 from above and below. The pair of buildup layers 152 form the first surface 105a and the second surface 105b of the package substrate 105. Each buildup layer 152 includes multiple insulating layers 152a and multiple wiring portions 152b. The core layer 151 has through holes 151a. The circuit board 2000 shown in FIG. 9A is sometimes called an FC-BGA (Flip Chip-Ball-Grid Array) substrate. The circuit board 2000 is mounted on a motherboard 500, which serves as its base, for use.

[0137] 9A and 9B , the package substrate 105 has a core layer 151 and a pair of buildup layers 152 that sandwich the core layer 151 from above and below. However, the package substrate 105 may be a so-called coreless substrate that does not have the core layer 151. In other words, the package substrate 105 may be composed of only the buildup layers 152.

[0138] As shown in FIG. 9A , the semiconductor chip 305 may be connected to the first surface 105a of the package substrate 105 via a first connection portion 400a provided on the first surface 105a of the package substrate 105. The first connection portion 400a electrically connects the semiconductor chip 305 to the package substrate 105 and fixes the semiconductor chip 305 to the package substrate 105. For example, solder, a conductive resin, or the like may be used as the first connection portion 400a. A first sealing resin 600a may be filled in the gap between the semiconductor chip 305 and the package substrate 105. A second sealing resin 600b may be molded to cover the semiconductor chip 305, further sealing the semiconductor chip 305. For example, a resin composition containing an epoxy resin and a curing agent may be used as the first sealing resin 600a and the second sealing resin 600b.

[0139] 9A , the circuit board 2000 may be connected to the upper surface 500a of the motherboard 500 via a second connection portion 400b provided on the second surface 105b of the package substrate 105. The second connection portion 400b electrically connects the circuit board 2000 to the motherboard 500 and fixes the circuit board 2000 to the motherboard 500. For example, solder, conductive resin, etc. may be used as the second connection portion 400a.

[0140] An insulating layer including the cured product of resin composition 20 of Embodiment 4 or the cured product of the prepreg of Embodiment 5 can be applied to insulating layer 152a of package substrate 105 included in circuit board 2000 in Modification 1. That is, an insulating layer including the cured product of resin composition 20 of Embodiment 4 or the cured product of the prepreg of Embodiment 5 may be insulating layer 152a of package substrate 105. An insulating layer including the cured product of resin composition 20 of Embodiment 4 or the cured product of the prepreg of Embodiment 5 is suitable for reducing the dielectric dissipation factor of a dielectric material, and therefore, by applying it as insulating layer 152a of package substrate 105, a circuit board 200 suitable for high frequencies can be provided.

[0141] 10 is a cross-sectional view showing an example of a circuit board 3000 according to Modification 2. Circuit board 3000 includes an insulating layer containing a cured product of resin composition 20 according to Embodiment 4 or a cured product of the prepreg according to Embodiment 5, and is therefore suitable for high frequencies.

[0142] The circuit board 3000 includes two or more semiconductor chips 305 and further includes an intermediate layer 106 between the package substrate 105 and the semiconductor chips 305. Active elements of the two or more semiconductor chips 305 are connected to the circuit of the intermediate layer 106. The intermediate layer 106 is connected to the package substrate 105. The intermediate layer 106 includes an insulating layer 161 and a wiring portion 162 that electrically connects the two or more semiconductor chips 305 to the package substrate 105. Except for these, the circuit board 3000 has the same configuration as the circuit board 2000 shown in FIG. 9A. For the configuration of the package substrate 105 of the circuit board 3000, refer to FIG. 9B. The intermediate layer 106 is sometimes called an organic interposer or an RDL interposer. The circuit board 3000 shown in FIG. 10 is sometimes called a 2D or 3D package. The circuit board 3000 is mounted on a motherboard 500 as a base for use.

[0143] 10 , two or more semiconductor chips 305 may be connected to the first surface 106a of the intermediate layer 106 via first connection portions 400a provided on the first surface 106a of the intermediate layer 106. The first connection portions 400a electrically connect the semiconductor chips 305 to the intermediate layer 106 and fix the semiconductor chips 305 to the intermediate layer 106. A first sealing resin 600a may be filled in each gap between the two or more semiconductor chips 305 and the intermediate layer 106. A second sealing resin 600b may be molded to cover the two or more semiconductor chips 305, further sealing the two or more semiconductor chips 305.

[0144] 10 , the intermediate layer 106 may be connected to the first surface 105a of the package substrate 105 via a third connection portion 400c provided on the first surface 105a of the package substrate 105. The third connection portion 400c electrically connects the intermediate layer 106 and the package substrate 105 and fixes the intermediate layer 106 to the package substrate 105. For example, solder, a conductive resin, or the like may be used as the third connection portion 400c. The gap between the intermediate layer 106 and the package substrate 105 may be filled with a third sealing resin 600c. For example, the resin compositions described for the first sealing resin 600a and the second sealing resin 600b may be used as the third sealing resin 600c.

[0145] 10 , the circuit board 3000 may be connected to the upper surface 500a of the motherboard 500 via a second connection portion 400b provided on the second surface 105b of the package substrate 105. The second connection portion 400b electrically connects the circuit board 3000 and the motherboard 500, and also fixes the circuit board 3000 to the motherboard 500.

[0146] The insulating layer including the cured product of resin composition 20 of Embodiment 4 or the cured product of the prepreg of Embodiment 5 can be applied to both insulating layer 152a of package substrate 105 and insulating layer 161 of intermediate layer 106 included in circuit board 3000 in Modification 2. That is, the insulating layer including the cured product of resin composition 20 of Embodiment 4 or the cured product of the prepreg of Embodiment 5 may be at least one selected from the group consisting of insulating layer 152a of package substrate 105 and insulating layer 161 of intermediate layer 106. The insulating layer including the cured product of resin composition 20 of Embodiment 4 or the cured product of the prepreg of Embodiment 5 is suitable for reducing the dielectric dissipation factor of a dielectric material, and therefore, by applying it as insulating layer 152a of package substrate 105 and / or insulating layer 161 of intermediate layer 106, a circuit board 3000 suitable for high frequencies can be provided.

[0147] 11 is a cross-sectional view showing an example of a circuit board 4000 according to Modification 3. Circuit board 4000 includes an insulating layer containing a cured product of resin composition 20 according to Embodiment 4 or a cured product of the prepreg according to Embodiment 5, and is therefore suitable for high frequencies.

[0148] The circuit board 4000 includes a redistribution layer 107 and a semiconductor chip 305 disposed on the redistribution layer 107. Active elements of the semiconductor chip 305 are connected to the circuit of the redistribution layer 107. The redistribution layer 107 includes an insulating layer 171 and a wiring portion 172 electrically connected to the semiconductor chip 305. The circuit board 4000 shown in FIG. 11 is sometimes called a wafer level package (WLP), a panel level package (PLP), or the like. The circuit board 4000 is mounted on a motherboard 500, which serves as a base, for use.

[0149] 11, a second sealing resin 600b may be molded to cover the semiconductor chip 305, thereby sealing the semiconductor chip 305. The semiconductor chip 305 may be fixed to the rewiring layer 107 by the second sealing resin 600b.

[0150] 11 , the circuit board 4000 may be connected to the upper surface 500a of the motherboard 500 via a second connection portion 400b provided on the second surface 107b of the redistribution layer 107. The second connection portion 400b electrically connects the circuit board 4000 and the motherboard 500, and also fixes the circuit board 4000 to the motherboard 500.

[0151] An insulating layer including the cured product of resin composition 20 of embodiment 4 or the cured product of the prepreg of embodiment 5 can be applied to insulating layer 171 of rewiring layer 107 included in circuit board 4000 in Modification 3. That is, an insulating layer including the cured product of resin composition 20 of embodiment 4 or the cured product of the prepreg of embodiment 5 may be insulating layer 171 included in rewiring layer 107. An insulating layer including the cured product of resin composition 20 of embodiment 4 or the cured product of the prepreg of embodiment 5 is suitable for reducing the dielectric loss tangent of a dielectric material, and therefore, by applying it as insulating layer 171 of rewiring layer 107, a circuit board 4000 suitable for high frequencies can be provided.

[0152] (Other Embodiments) (Additional Notes) The above description of the embodiments discloses the following techniques.

[0153] (Technology 1) A method for producing a composite material having a dielectric loss tangent lower than that of a metal organic framework containing a plurality of metal ions, the method comprising: bringing the metal organic framework into contact with a binding polymer; and complexing the metal organic framework with the binding polymer so that a binding state of at least one metal ion among the plurality of metal ions changes.

[0154] According to the method for producing a composite material of Technology 1, it is possible to produce a composite material having a metal organic framework in which a reduction in dielectric loss tangent is realized due to a change in the coordination environment of metal ions.

[0155] (Technology 2) The method for producing a composite material according to Technology 1, wherein the at least one metal ion is present on the surface of the metal organic framework.

[0156] The method for producing a composite material according to Technology 2 may be the method for producing a composite material according to Technology 1, wherein the conjugating of the binding polymer to the metal organic framework comprises conjugating the binding polymer to the metal organic framework so that a binding state of the at least one metal ion present on the surface of the metal organic framework is changed.

[0157] According to this configuration, it is easy to manufacture a composite material in which a reduced dielectric tangent is realized.

[0158] (Technology 3) A composite material comprising: a metal organic framework containing a plurality of metal ions; and a binding polymer, wherein the binding polymer is bound to at least one metal ion among the plurality of metal ions.

[0159] According to the composite material of Technology 3, a reduction in the dielectric loss tangent can be achieved.

[0160] (Technology 4) The composite material according to Technology 3, wherein the binding polymer is attached to the surface of the metal organic framework.

[0161] A composite material having such a configuration can achieve a further reduction in the dielectric loss tangent.

[0162] (Technology 5) The composite material according to Technology 3 or 4, wherein the associative polymer contains a nitrogen-containing heterocycle.

[0163] A composite material having such a configuration can achieve a further reduction in the dielectric loss tangent.

[0164] (Technology 6) The composite material according to any one of Technologies 3 to 5, wherein the associative polymer includes at least one selected from the group consisting of an indole skeleton, an indoline skeleton, and a phenol skeleton.

[0165] A composite material having such a configuration can achieve a further reduction in the dielectric loss tangent.

[0166] (Technology 7) The composite material according to any one of Technologies 3 to 6, wherein the associative polymer comprises a silicon-containing polymer, and the silicon-containing polymer comprises a main chain containing at least one selected from the group consisting of a styrene unit, a butadiene unit, an ethylene unit, a cycloolefin unit, and a fluorine-containing olefin unit.

[0167] A composite material having such a configuration can achieve a further reduction in the dielectric loss tangent.

[0168] (Technology 8) An insulating material comprising the composite material according to any one of technologies 3 to 7.

[0169] According to the insulating material of Technology 8, an insulating material exhibiting a low dielectric loss tangent can be provided.

[0170] (Technology 9) A filler comprising the composite material according to any one of technologies 3 to 7.

[0171] According to the filler of Technology 9, a filler exhibiting a low dielectric tangent can be provided.

[0172] (Technology 10) A resin composition comprising the filler according to Technology 9.

[0173] According to the resin composition of Technique 10, a resin composition exhibiting a low dielectric tangent can be provided.

[0174] (Technology 11) A prepreg comprising the resin composition according to Technology 10 or a semi-cured product of the resin composition.

[0175] According to the prepreg of Technology 11, a prepreg exhibiting a low dielectric tangent can be provided.

[0176] (Technology 12) A resin-coated film comprising: a resin layer containing the resin composition according to Technology 10 or a semi-cured product of the resin composition; and a support film.

[0177] According to the resin-coated film of Technique 12, a resin-coated film exhibiting a low dielectric loss tangent can be provided.

[0178] (Technology 13) A resin-coated metal foil comprising: a resin layer containing the resin composition according to Technology 10 or a semi-cured product of the resin composition; and a metal foil.

[0179] According to the resin-coated metal foil of Technique 13, it is possible to provide a resin-coated metal foil that exhibits a low dielectric loss tangent.

[0180] (Technology 14) A metal-clad laminate comprising an insulating layer containing a cured product of the resin composition according to Technology 10 or a cured product of the prepreg according to Technology 11, and a metal foil.

[0181] According to the metal-clad laminate of Technology 14, it is possible to provide a metal-clad laminate exhibiting a low dielectric tangent.

[0182] (Technology 15) A wiring board comprising: an insulating layer containing a cured product of the resin composition according to Technology 10 or a cured product of the prepreg according to Technology 11; and wiring.

[0183] According to the wiring board of Technology 15, it is possible to provide a wiring board that exhibits a low dielectric loss tangent.

[0184] (Technology 16) A sealing material for circuit boards, comprising the resin composition according to Technology 10.

[0185] According to the sealing material for circuit boards of Technique 16, it is possible to provide a sealing material for circuit boards that exhibits a low dielectric loss tangent.

[0186] (Technology 17) An adhesive material for circuit boards, comprising the resin composition according to Technology 10 or a semi-cured product of the resin composition.

[0187] According to the adhesive material for circuit boards of Technology 17, an adhesive material for circuit boards exhibiting a low dielectric loss tangent can be provided.

[0188] (Technology 18) A circuit board having an insulating layer containing a cured product of the resin composition according to Technology 10 or a cured product of the prepreg according to Technology 11.

[0189] According to the circuit board of Technology 18, it is possible to improve chemical stability while suppressing increases in the relative dielectric constant and the dielectric loss tangent, and it is also possible to provide a circuit board suitable for high frequencies.

[0190] (Technology 19) The circuit board according to Technology 18, further comprising a package substrate and a semiconductor chip disposed on the package substrate, wherein the insulating layer is at least one selected from the group consisting of an insulating layer included in the package substrate and an insulating layer included in an intermediate layer located between the semiconductor chip and the package substrate.

[0191] The circuit board of Technology 19 is suitable for high frequencies.

[0192] (Technology 20) The circuit board according to Technology 18, further comprising a redistribution layer and a semiconductor chip disposed on the redistribution layer, wherein the redistribution layer includes the insulating layer.

[0193] The circuit board of Technology 20 is suitable for high frequencies.

[0194] The present disclosure will be specifically described below with reference to examples. The examples are intended to illustrate the present disclosure and are not intended to limit the scope of the present disclosure.

[0195] Example 1 MOF ZIF-8 particles (manufactured by Aldrich, product name: Basolite Z1200) were used as the MOF.

[0196] [Binding Polymer] Polydopamine was used as the binding polymer.

[0197] [Synthesis of Composite Material] A Tris buffer solution was prepared by dissolving 1.470 g of tris(hydroxymethyl)aminomethane in 101.0 mL of distilled water. 35.0 mL of isopropanol was added to the Tris buffer solution, followed by 2 g of ZIF-8 particles. The mixture was stirred with a magnetic stirrer to obtain a first solution. 0.0630 g of 3-hydroxytyramine hydrochloride was dissolved in 4 mL of distilled water to obtain a second solution. The second solution was added to the first solution and stirred at room temperature for 60 minutes, followed by stirring at 72°C for 3 hours to obtain a third solution. The third solution was washed with methanol and then filtered to obtain a powder. The powder was dried in the air. This composite process yielded particles of the composite material of Example 1. The color of the powder changed from white to gray, characteristic of polydopamine, confirming that the surface of the ZIF-8 particles was modified with polydopamine.

[0198] [Confirmation of Bonding of Binding Polymer] The fact that polydopamine was bonded to the surface of ZIF-8 in the composite material of Example 1 was confirmed by the C1s XPS spectrum, the N1s XPS spectrum, and the O1s XPS spectrum.

[0199] Figure 12 shows the C1s XPS spectrum of the composite material of Example 1. Figure 13 shows the C1s XPS spectrum of ZIF-8. In Figures 12 and 13, the horizontal axis represents binding energy (eV) and the vertical axis represents intensity in arbitrary units. As shown in Figure 12, in the C1s XPS spectrum of the composite material of Example 1, a new bond component was confirmed on the high binding energy side, and peak separation confirmed the presence of C-OH and C=O bonds in polydopamine.

[0200] FIG. 14 shows the N1s XPS spectrum of the composite material of Example 1. FIG. 15 shows the N1s XPS spectrum of ZIF-8. As shown in FIG. 14, the N1s XPS spectrum of the composite material of Example 1 confirmed the amplification of the bond component on the high binding energy side. From the peak separation of the N1s XPS spectrum, in the N1s XPS spectrum of FIG. 14, the ratio of the pyrrole NH component peak to the sum of the pyrrole NH component peak and the pyridine NH component peak was 18%, and in the N1s XPS spectrum of FIG. 15, the ratio of the pyrrole NH component peak to the sum of the pyrrole NH component peak and the pyridine NH component peak was 11%. The presence of polydopamine having a pyrrole skeleton was also confirmed by the amplification of the pyrrole NH component in the N1s XPS spectrum of FIG. 14.

[0201] Figure 16 shows the O1s XPS spectrum of the composite material of Example 1. Figure 17 shows the O1s XPS spectrum of ZIF-8. As shown in Figure 16, the O1s XPS spectrum of the composite material of Example 1 showed an increase in intensity, confirming the presence of polydopamine having a catechol or quinone skeleton.

[0202] In Non-Patent Document 2, it has been shown by first-principles calculations that nitrogen and oxygen atoms in polydopamine are chelated to metal ions on the surface of ZIF-8. Therefore, it is presumed that in the composite material of Example 1, polydopamine is also bound to the metal sites on the surface of ZIF-8 by chelate coordination.

[0203] Example 2 [MOF] The same ZIF-8 particles as in Example 1 were used as the MOF.

[0204] [Binding Polymer] Polyvinylpyridine (manufactured by Aldrich, average molecular weight 60,000) was used as the binding polymer.

[0205] [Synthesis of Composite Material] 1.000 g of ZIF-8 particles was added to 40 mL of methanol and stirred with a magnetic stirrer to obtain a first solution. 1.000 g of polyvinylpyridine was dissolved in 10 mL of methanol to obtain a second solution. The second solution was added to the first solution and stirred at room temperature for 24 hours to obtain a third solution. The third solution was washed with methanol and then filtered to obtain a powder. The powder was dried in the air. This composite process yielded particles of the composite material of Example 2. The color of the powder changed from white to blue, which is characteristic of polyvinylpyridine, confirming that the surface of the ZIF-8 particles had been modified with polyvinylpyridine.

[0206] [Confirmation of Bonding of Binding Polymer] In the composite material of Example 2, the bonding of polyvinylpyridine to the surface of ZIF-8 was confirmed by the color change of the powder and TOF-SIMS.

[0207] The ZIF-8 particles were white, whereas the composite material of Example 2 was blue. This is thought to indicate that in the composite material of Example 2, the pyridine-N in polyvinylpyridine bound to the Zn site on the surface of the ZIF-8 particles, changing the Zn coordination environment, or that metal-to-ligand charge transfer (MLCT) or ligand-to-metal charge transfer (LMCT) occurred, resulting in a change in the light absorption properties.

[0208] Figure 18 shows the TOF-SIMS data of the composite material of Example 2 and ZIF-8. In Figure 18, the horizontal axis shows the types of fragments of ZIF-8 and polyvinylpyridine extracted by multivariate analysis of the standard sample, and the vertical axis shows the normalized intensity of each fragment. As shown in Figure 18, in the composite material of Example 2, the C7H8N corresponding to the fragment of polyvinylpyridine + , C7H8N2 + , C8H8N2 + The presence of polyvinylpyridine was confirmed by the increase in the intensity of the spectrum.

[0209] Example 3 [MOF] The same ZIF-8 particles as in Example 1 were used as the MOF.

[0210] [Binding Polymer] Polyethylene glycol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., average molecular weight 3000) was used as the binding polymer.

[0211] [Synthesis of Composite Material] 1.000 g of ZIF-8 particles was added to 40 mL of methanol and stirred with a magnetic stirrer to obtain a first solution. 1.000 g of polyethylene glycol was dissolved in 10 mL of methanol to obtain a second solution. The second solution was added to the first solution and stirred at room temperature for 24 hours to obtain a third solution. The third solution was washed with methanol and then filtered to obtain a powder. The powder was dried in the air. Through this composite process, particles of the composite material of Example 3 were obtained.

[0212] Example 4 [MOF] The same ZIF-8 particles as in Example 1 were used as the MOF.

[0213] [Synthesis of binding polymer] A silicon-containing polymer represented by the formula (3) was synthesized. Specifically, a styrene-butadiene copolymer represented by the formula (4) (manufactured by Nippon Soda Co., Ltd., product number: 1,2-SBS) and an organosilicon compound represented by the formula (5) (manufactured by Tokyo Chemical Industry Co., Ltd., product number: T1035, m = 3, R 6 =-CH3) was hydrosilylated in the presence of a platinum catalyst. This resulted in the production of a silicon-containing polymer represented by the above formula (3). The composition of the resulting silicon-containing polymer was as follows: 1 The ratio of the integrals of the peaks corresponding to each functional group in the profile obtained by H nuclear magnetic resonance (NMR) measurement (600 MHz) was determined. The NMR apparatus used was a JEOL JNM ECZ600R. As a result, the silicon-containing polymer obtained had the following structure in the above formula (3): a = 5, b = 61, c = 13, d = 5, m = 3, R 6 = methyl group (-CH3). The silylation rate of the obtained silicon-containing polymer was 17.6%. The silylation rate was calculated by the formula: -SiR 2 3-m (OR1 ) m The ratio of the terminals into which the functional group was introduced to the terminals into which the functional group was not introduced was calculated.

[0214] [Synthesis of Composite Material] A first solution was obtained by dissolving 2.5 g of silicon-containing polymer in 5 mL of toluene. Next, 2 g of ZIF-8 particles were added to 20 mL of toluene, and the particles were dispersed using an ultrasonic cleaner to obtain a second solution. The first solution was added to the second solution while stirring with a magnetic stirrer, and the mixture was stirred at room temperature for 12 hours to obtain a third solution. A powder was obtained by filtering the third solution. Toluene was added to the powder, and ultrasonic dispersion was performed, followed by centrifugation to remove the supernatant. The above washing procedure was repeated three times, and then the mixture was dried in the air. Through this composite process, particles of the composite material of Example 4 were obtained.

[0215] [Confirmation of Bonding of the Bonding Polymer] The bonding of the silicon-containing polymer to the surface of ZIF-8 in the composite material of Example 4 was confirmed by the infrared absorption spectrum and O1s XPS spectrum of the composite material. The infrared absorption spectrum was obtained by the diffuse reflectance method of Fourier transform infrared spectroscopy (FT-IR).

[0216] 19 shows the infrared absorption spectrum of the composite material of Example 4 and the infrared absorption spectrum of ZIF-8. In FIG. 19, the horizontal axis represents wave number (cm -1 ), and the vertical axis represents transmittance (%). Since Fig. 19 is a graph for comparing the trends of the two infrared absorption spectra, the scale of the vertical axis is omitted. As shown in Fig. 19, peak P4 derived from the deformation vibration of the vinyl group was observed in the composite material of Example 4, confirming the presence of a silicon-containing polymer on the surface of ZIF-8.

[0217] Figure 20 shows the O1s XPS spectrum of the composite material of Example 4. Figure 21 shows the O1s XPS spectrum of ZIF-8. In Figures 20 and 21, the horizontal axis represents binding energy (eV) and the vertical axis represents intensity in arbitrary units. As shown in Figure 20, Si-O-Zn bonds and Si-O-Si bonds were confirmed by peak separation in the O1s XPS spectrum of the composite material of Example 4. These results confirmed that in the composite material of Example 4, the silicon-containing polymer was immobilized on the surface of ZIF-8 via bonds including Zn-O-Si bonds.

[0218] Comparative Example 1 The ZIF-8 particles used in Example 1 were used as the material particles for Comparative Example 1.

[0219] The dielectric loss tangent of each of the particles obtained in Examples 1 to 4 and Comparative Example 1 was evaluated based on the method described below.

[0220] [Evaluation of Particle Pore Volume] The pore volume of each particle at a relative pressure of 0.90 was measured by nitrogen adsorption measurement at 77 K. A BELSORP MINI X manufactured by Microtrac-Bell was used as the nitrogen adsorption measurement device. Before the measurement, each particle was pretreated under vacuum (10 Pa or less) at 200°C for 1 hour. The pore volume measurement results are shown in Table 1.

[0221] [Evaluation of Dielectric Loss Tangent of Particles Before and After Composite Formation] Using a cavity resonance method at a frequency of 1 GHz, the dielectric loss tangent of each particle before and after composite formation was determined by the following method. That is, the dielectric loss tangent of the ZIF-8 particles and the dielectric loss tangent of the particles of each composite material were determined. An MS46122B manufactured by AET Corporation was used as the cavity resonator. For the measurement, the particles were pretreated under conditions of vacuum (10 Pa or less), 200°C, and 1 hour. Thereafter, the particles were packed into a sample tube under a N2 atmosphere without exposure to the atmosphere, and measurements were performed. Next, the particles were left in an atmosphere with a humidity of 35% to 60% for 4 days or more, and then measurements were performed again. The packing fraction of the sample tube was calculated from the true density of the ZIF-8 particles, and the dielectric loss tangent of the particles was calculated. The dielectric loss tangent of the particles was calculated by converting the measured value into the packing fraction of the sample tube. The packing ratio of the sample tube was determined from the mass of the particles, the bulk volume occupied by the particles in the sample tube, and the true density of the ZIF-8 particles. The true density of the ZIF-8 particles was determined from the density calculated from the crystal structure (0.921 g / cm 3 ) was used. The true density of the particles after composite formation was determined from the following formulas (X1) and (Y1). The porosity of the ZIF-8 particles was set to 50%. The measurement results of the dielectric tangent are shown in Table 1. True density of particles after composite formation = (density calculated from the crystal structure of the ZIF-8 particles) ÷ {(porosity of ZIF-8 particles × 0.01) × (void maintenance rate) × 0.01} ... formula (X1) Void maintenance rate = (pore volume of particles after composite formation) ÷ (pore volume of ZIF-8 particles before composite formation) ... formula (Y1)

[0222]

[0223] <<Discussion>> As shown in Table 1, the dielectric loss tangents of the composite materials of Examples 1 to 4 were lower in both an N2 atmosphere and air than the dielectric loss tangent of the ZIF-8 particles of Comparative Example 1. From this result, it can be determined that the dielectric loss tangent was reduced by the composite. In addition, in Examples 1 to 4, the binding polymer was bound to ZIF-8, and the dielectric loss tangent was lower than that of Comparative Example 1, suggesting that the binding polymer was bound to at least one of the multiple metal ions contained in ZIF-8.

[0224] As described above, the composite materials of Examples 1 to 4 exhibited low dielectric loss tangents. Therefore, by using such composite materials as fillers, for example, it is expected that resin compositions containing the fillers will have low dielectric loss tangents. By using such resin compositions as materials for insulating layers, it is possible to provide products that can be mounted as insulating layers on wiring boards.

[0225] In Examples 1 to 4, ZIF-8 was used as the MOF, but even if other ZIFs such as ZIF-4, ZIF-7, ZIF-12, ZIF-67, ZIF-90, and ZIF-412 were used instead of ZIF-8, it is expected that the dielectric loss tangent would decrease similarly to Examples 1 to 4. Furthermore, even if an MOF other than ZIF is used as the MOF, it is expected that the dielectric loss tangent would decrease similarly to Examples 1 to 4. This is because the composite material of the present disclosure achieves a decrease in the dielectric loss tangent by binding a binding polymer to at least one metal ion among multiple metal ions contained in the MOF.

[0226] In order to express the present disclosure, the present disclosure has been appropriately and sufficiently described above through the embodiments, but it should be recognized that those skilled in the art can easily change and / or improve the above-described embodiments. Therefore, unless the changes or improvements made by those skilled in the art are at a level that deviates from the scope of the claims described in the claims, the changes or improvements are interpreted as being included in the scope of the claims.

[0227] The composite material of the present disclosure can be used as an insulating material, filler, etc. having a low dielectric tangent, and is therefore suitable for applications such as wiring boards for electronic devices used in high-capacity communications.

[0228] REFERENCE SIGNS LIST 1 Metal-organic framework (MOF) 2 Binding polymer 10 Composite material 20 Resin composition 22 Filler 24 Curable resin 30 Resin-attached film 32 Resin layer 34 Support film 40 Resin-attached metal foil 42 Resin layer 44 Metal foil 50 Metal-clad laminate 52 Insulating layer 54 Metal foil 60 Wiring board 62 Insulating layer 64 Wiring 1000, 2000, 3000, 4000 Circuit board 100 Wiring board 101 Core layer 101a First surface 101b Second surface 111 Conductor layer 112 Through hole 102 Wiring laminate portion 121 Conductor layer 122 Insulating layer 105 Package substrate 105a First surface 105b Second surface 151 Core layer 151a Through hole 152 Build-up layer 152a Insulating layer 152b Wiring portion 106 Intermediate layer 106a First surface 161 Insulating layer 162 Wiring portion 107 Rewiring layer 107b Second surface 171 Insulating layer 172 Wiring portion 200 Antenna substrate 201 Insulating layer 201a First surface 201b Second surface 202 Antenna element 300 RFIC 305 Semiconductor chip 400 Connecting portion 400a First connecting portion 400b Second connecting portion 400c Third connecting portion 500 Motherboard 500a Upper surface 600a First sealing resin 600b Second sealing resin 600c Third sealing resin

Claims

1. A method for producing a composite material having a dielectric tangent lower than that of a metal organic framework containing a plurality of metal ions, the method comprising: contacting the metal organic framework with an associative polymer; and complexing the metal organic framework with the associative polymer so that a bonding state of at least one metal ion among the plurality of metal ions is changed.

2. The method for producing a composite material according to claim 1, wherein the at least one metal ion is present on a surface of the metal-organic framework.

3. A composite material comprising: a metal-organic framework including a plurality of metal ions; and a binding polymer, the binding polymer binding to at least one metal ion of the plurality of metal ions.

4. The composite material of claim 3, wherein the associative polymer is attached to a surface of the metal-organic framework.

5. The composite material according to claim 3, wherein the associative polymer comprises a nitrogen-containing heterocycle.

6. The composite material according to claim 3, wherein the associative polymer contains at least one selected from the group consisting of an indole skeleton, an indoline skeleton, and a phenol skeleton.

7. The composite material according to claim 3, wherein the associative polymer comprises a silicon-containing polymer, and the silicon-containing polymer comprises a main chain containing at least one unit selected from the group consisting of a styrene unit, a butadiene unit, an ethylene unit, a cycloolefin unit, and a fluorine-containing olefin unit.

8. An insulating material comprising the composite material according to claim 3.

9. A filler comprising the composite material according to claim 3.

10. A resin composition comprising the filler according to claim 9.

11. A prepreg comprising the resin composition according to claim 10 or a semi-cured product of said resin composition.

12. A resin-coated film comprising a resin layer containing the resin composition according to claim 10 or a semi-cured product of said resin composition, and a support film.

13. A resin-coated metal foil comprising: a resin layer containing the resin composition according to claim 10 or a semi-cured product of said resin composition; and a metal foil.

14. A metal-clad laminate comprising an insulating layer containing a cured product of the resin composition according to claim 10, or a cured product of a prepreg containing said resin composition or a semi-cured product of said resin composition, and a metal foil.

15. A wiring board comprising: an insulating layer containing a cured product of the resin composition according to claim 10, or a cured product of a prepreg containing said resin composition or a semi-cured product of said resin composition; and wiring.

16. A sealing material for circuit boards, comprising the resin composition according to claim 10.

17. An adhesive material for circuit boards, comprising the resin composition according to claim 10 or a semi-cured product of said resin composition.

18. A circuit board comprising an insulating layer comprising a cured product of the resin composition according to claim 10, or a cured product of a prepreg comprising said resin composition or a semi-cured product of said resin composition.

19. The circuit board according to claim 18, further comprising: a package substrate; and a semiconductor chip disposed on the package substrate, wherein the insulating layer is at least one selected from the group consisting of an insulating layer included in the package substrate and an insulating layer included in an intermediate layer located between the semiconductor chip and the package substrate.

20. The circuit board according to claim 18, further comprising: a redistribution layer; and a semiconductor chip disposed on the redistribution layer, the redistribution layer including the insulating layer.

Images