Method for producing insulating material, insulating material, and applied product of insulating material

Abstract

A method for producing an insulating material according to one embodiment of the present disclosure is a method for producing an insulating material having a dielectric loss tangent lower than the dielectric loss tangent of a metal-organic framework containing a plurality of first ligands, the method comprising: bringing a plurality of first ligands or second ligands having a structure different from the structure of each of the plurality of first ligands into contact with the metal-organic framework; (a) replacing at least a portion of the plurality of first ligands contained in the metal-organic framework with the second ligands; and (b) performing at least one selected from the group consisting of adding a plurality of first ligands or second ligands to the metal-organic framework.

Description

Manufacturing method of insulating material, insulating material, and applied product of insulating material

[0001] The present disclosure relates to a method for manufacturing an insulating material, the insulating material, and an application product of the insulating 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 replacing a ligand contained in a metal-organic framework with another ligand.

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

[0004] Xinlei Liu, Yanshuo Li, Yujie Ban, Yuan Peng, Hua Jin, Helge Bux, Longya Xu, Jurgen Caro and Weishen Yang, Chem. Commun., 2013, 49, vol. 49, 9140-9142Pravas Deria, Yongchul G. Chung, Randall Q. Snurr, Joseph T.Hupp and Omar K. Farha, Chem Sci, 2015, vol. 6, 5172

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

[0006] The method for producing an insulating material according to the present disclosure is a method for producing an insulating material having a dielectric loss tangent lower than that of a metal-organic framework comprising a plurality of first ligands, the method comprising: bringing the metal-organic framework into contact with the plurality of first ligands or a second ligand having a structure different from each of the plurality of first ligands; and performing at least one selected from the group consisting of: (a) exchanging at least a portion of the plurality of first ligands contained in the metal-organic framework with the second ligand; and (b) adding the plurality of first ligands or the second ligand to the metal-organic framework.

[0007] The insulating material of the present disclosure comprises a metal-organic framework, the metal-organic framework including a plurality of first ligands and a second ligand, and the structure of each of the plurality of first ligands is different from the structure of the second ligand.

[0008] According to the present disclosure, it is possible to provide a method for producing an insulating material suitable for producing an insulating material having a metal organic framework and realizing a reduced dielectric dissipation factor, and an insulating material having a metal organic framework and realizing a reduced dielectric dissipation factor.

[0009] FIG. 1A is a diagram showing a schematic configuration of an insulating material according to Embodiment 1. FIG. 1B is a diagram showing a schematic configuration of a metal-organic framework before a second ligand is allowed to act on the insulating material according to Embodiment 1. FIG. 2A is a diagram showing an example of the structure of an insulating material according to Embodiment 1. FIG. 2B is a diagram showing the structure of a metal-organic framework before a second ligand is allowed to act on the insulating material according to Embodiment 1. FIG. 3 is a flowchart showing an example of a method for producing an insulating material according to Embodiment 1. FIG. 4 is a diagram showing a schematic configuration of a resin composition according to Embodiment 3. FIG. 5 is a cross-sectional view of a resin-coated film according to Embodiment 5. FIG. 6 is a cross-sectional view of a resin-coated metal foil according to Embodiment 6. FIG. 7 is a cross-sectional view of a metal-clad laminate according to Embodiment 7. FIG. 8 is a cross-sectional view of a wiring board according to Embodiment 8. FIG. 9 is a cross-sectional view of an example of a circuit board according to Embodiment 11. FIG. 10A is a cross-sectional view of an example of a circuit board according to Modification 1. FIG. 10B is a partially enlarged view of FIG. 10A. FIG. 11 is a cross-sectional view of an example of a circuit board according to Modification 2. FIG. 12 is a cross-sectional view of an example of a circuit board according to Modification 3. FIG. 13 is a cross-sectional view of the insulating material according to Example 1-a. 1 14 is a diagram showing the H-NMR spectrum of the insulating material of Example 2. 1 15 is a diagram showing the H-NMR spectrum of the insulating material of Example 3. 1 16 shows the X-ray diffraction pattern of the particles synthesized in Example 4 and the simulated X-ray diffraction pattern of NU-1000. 1 18 is a diagram showing the H-NMR spectrum of the insulating material of Example 4. 119 is a diagram showing the H-NMR spectrum of the insulating material of Example 5. 1 FIG. 1 shows a H-NMR spectrum.

[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 trend toward higher integration and smaller size 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 the reduction of the dielectric loss tangent of metal-organic frameworks, and as a result have arrived at the method for controlling the dielectric loss tangent of a metal-organic framework and the insulating 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. 1A to 3. FIG.

[0018] 1A is a diagram showing a schematic configuration of an insulating material 10 according to embodiment 1. The insulating material 10 includes a metal-organic framework (hereinafter referred to as "MOF") 1. The MOF 1 includes a plurality of first ligands 22a and second ligands 22b each having a structure different from that of each of the plurality of first ligands 22a.

[0019] 1A , MOF1 further includes a plurality of metal ions 21. In the insulating material 10, MOF1 includes second ligands 22b in addition to first ligands 22a, which can reduce the charge imbalance around the metal ions 21. As a result, the insulating material 10 can have a lower dielectric tangent than MOF1 that includes only a plurality of first ligands 22a as ligands.

[0020] The insulating material 10 can be synthesized, for example, by reacting a second ligand 22b with a MOF1 containing a plurality of first ligands 22a. In the present disclosure, the term "MOF1" refers to both the MOF1 before the second ligand is reacted with the MOF1 and the MOF1 after the second ligand is reacted with the MOF1. FIG. 1B is a diagram showing a schematic configuration of the MOF1 before the second ligand 22b is reacted with the MOF1. The MOF1 shown in FIG. 1B can be considered as a MOF having a first mother framework 2a containing a plurality of metal ions 21 and a plurality of first ligands 22a. On the other hand, the MOF1 included in the insulating material 10 shown in FIG. 1A can be considered as a MOF having a second mother framework 2b containing a plurality of metal ions 21, a plurality of first ligands 22a, and a second ligand 22b. By reacting the second ligand 22b with the MOF1 shown in FIG. 1B, the framework of the MOF1 changes from the first framework 2a to the second framework 2b, thereby synthesizing the insulating material 10.

[0021] Typically, within MOF1, metal ions 21 or metal clusters have a predetermined number of coordination sites, and first ligands 22a are bound to each of these coordination sites. However, among the coordination sites possessed by metal ions 21 or metal clusters, there may be sites in MOF1 to which first ligands 22a are not bound. Such coordination sites to which first ligands 22a are not bound suffer from charge imbalance. Ligand defects in MOF1 can be repaired by applying second ligands 22b having a structure different from that of the first ligands 22a to the coordination sites to which first ligands 22a are not bound. This improves the symmetry of the coordination environment around the metal ions 21. By improving the symmetry of the coordination environment around the metal ions 21, charge imbalance around the metal ions 21 can be reduced. As a result, the insulating material 10 can have a lower dielectric tangent than an MOF1 that includes only the plurality of first ligands 22a as ligands.

[0022] On the surface of MOF1, among the coordination sites possessed by the metal ion 21 or metal cluster, there is at least one site to which a first ligand 22a is not bound. Such coordination sites to which a first ligand 22a is not bound exhibit charge imbalance. By acting a second ligand 22b on a coordination site to which a first ligand 22a is not bound, it becomes possible for the second ligand 22b to bind to a coordination-capable, unsaturated metal ion 21 exposed on the surface of MOF1. When the second ligand 22b binds to the unsaturated metal ion 21 on the surface of MOF1, the coordination environment of the metal ion 21 changes. Specifically, the coordination environment of the metal ion 21 changes from a coordination-unsaturated environment to a coordination-saturated environment. This improves the symmetry of the coordination environment around the metal ion 21. By improving the symmetry of the coordination environment around the metal ion 21, the charge imbalance around the metal ion 21 can be reduced. As a result, the insulating material 10 can have a lower dielectric tangent than an MOF1 that includes only the plurality of first ligands 22a as ligands.

[0023] In the insulating material 10, the fact that the MOF1 includes the first ligand 22a and the second ligand 22b means, for example,1 H nuclear magnetic resonance (NMR) spectrum of MOF1 before the second ligand 22b was added. 1 This can be confirmed by comparing with the H-NMR spectrum.

[0024] From another perspective, the insulating material 10 has a structure in which second ligands 22b are incorporated into an MOF1 containing a plurality of first ligands 22a.

[0025] The second ligand 22b may be incorporated into the MOF 1 by replacing some or all of the multiple first ligands 22a contained in the MOF 1 with the second ligand 22b. The insulating material 10 may have a second mother framework 2b having a structure in which some or all of the multiple first ligands 22a contained in the first mother framework 2a of the MOF 1 are replaced with the second ligand 22b.

[0026] The second ligand 22b may be incorporated into the MOF 1 by adding the second ligand 22b to the MOF 1. The insulating material 10 may have a second mother framework 2b having a structure in which the second ligand 22b is added to the first mother framework 2a of the MOF 1.

[0027] The second ligand 22b may be incorporated into the MOF 1 by both replacing some or all of the multiple first ligands 22a contained in the MOF 1 with the second ligand 22b and adding the second ligand 22b to the MOF 1. The insulating material 10 may have a second mother framework 2b having a structure in which some or all of the multiple first ligands 22a contained in the first mother framework 2a of the MOF 1 are replaced with the second ligand 22b and the second ligand 22b is added to the first mother framework 2a of the MOF 1.

[0028] In the insulating material 10, the number of atoms contained in the second ligand 22b may be greater than the number of atoms contained in the first ligand 22a. It is desirable that the number of atoms contained in the second ligand 22b be greater than the number of atoms contained in the first ligand 22a by at least one.

[0029] In the insulating material 10, the molecular weight of the second ligand 22b may be larger than the molecular weight of the first ligand 22a. The molecular weight of the second ligand 22b is preferably larger than the molecular weight of the first ligand 22a by 1 or more.

[0030] If the number of atoms contained in the second ligand 22b is greater than the number of atoms contained in the first ligand 22a, the molecular mobility of the second ligand 22b will be lower than that of the first ligand 22a. If the molecular weight of the second ligand 22b is greater than that of the first ligand 22a, the molecular mobility of the second ligand 22b will be lower than that of the first ligand 22a. When an AC voltage is applied to the dielectric, the molecules vibrate, converting a portion of the electrical energy into thermal energy within the dielectric, resulting in a loss of electrical energy. The dielectric dissipation factor is an index representing the rate of this electrical energy loss. Low molecular mobility of the ligand suppresses molecular vibration, thereby reducing electrical energy loss. Therefore, if MOF1 contains a second ligand 22b with lower molecular mobility than the first ligand 22a, the dielectric dissipation factor of the insulating material 10 may be further reduced.

[0031] If the number of atoms contained in the second ligand 22b is greater than the number of atoms contained in the first ligand 22a, diffusion of the second ligand 22b into the interior of the MOF1 may be suppressed during the process of acting the second ligand 22b on the MOF1. Furthermore, if the number of atoms contained in the second ligand 22b is greater than the number of atoms contained in the first ligand 22a, the action of the second ligand 22b on the MOF1 may not be permitted, depending on the MOF1. Specifically, the action of the second ligand 22b may be limited to the vicinity of the surface of the MOF1, where the second ligand 22b is accessible. Generally, the proportion of ligand defects in the MOF1 is more pronounced near the surface. Furthermore, from the perspective of molecular mobility of the ligand, the ligands present near the surface of the MOF1 have higher molecular mobility than the ligands present inside the MOF1. That is, the effect of the delayed response of the polarization component in MOF 1 is more pronounced near the surface. Therefore, even if the access of the second ligand 22b is limited to the vicinity of the surface of MOF 1, it is presumed that the effect of reducing the dielectric loss tangent of the insulating material 10 can be obtained.

[0032] MOF1 and the ligands are described in more detail below.

[0033] [MOF] The MOF1 may comprise a zeolitic imidazolate framework (hereinafter referred to as "ZIF") and metal oxide clusters.

[0034] 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.

[0035] 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.

[0036] The MOF 1 may be a ZIF. The first mother skeleton 2a of the MOF 1 may be a ZIF.

[0037] 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 bridging ligands of such metal oxide clusters include, for example, a carboxylate group (-COO) or a hydroxy group (-OH).

[0038] 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.

[0039] The MOF1 may be a Zr-MOF. The first mother skeleton 2a of the MOF1 may be a Zr-MOF.

[0040] 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.

[0041] As MOF1, one selected from the group consisting of ZIF particles and Zr-MOF 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.

[0042] [Ligand] The first ligand 22a has a first atom that coordinates to the metal ion 21. Examples of the first atom include a nitrogen atom, an oxygen atom, a sulfur atom, a phosphorus atom, and a halogen atom. Halogen atoms include a chlorine atom, a fluorine atom, a bromine atom, and an iodine atom. The first atom may be a nitrogen atom, an oxygen atom, or a sulfur atom, or may be a nitrogen atom or an oxygen atom. The first atom may be a nitrogen atom.

[0043] The second ligand 22b may have at least one first atom, which promotes the action of the second ligand 22b on the MOF 1. This is expected to result in the insulating material 10 having a lower dielectric tangent.

[0044] The number of first atoms in the second ligand 22b may be equal to the number of first atoms in the first ligand 22a. In this case, the effect of the second ligand 22b on the MOF 1 is further promoted. This is expected to result in the insulating material 10 having a lower dielectric tangent.

[0045] The first ligand 22a may have a ring structure including the first atom.

[0046] Examples of the ring structure containing the first atom include an aromatic hydrocarbon ring, an aliphatic hydrocarbon ring, and a heterocyclic ring. Examples of the aromatic hydrocarbon ring include C rings such as a benzene ring and a naphthalene ring. 6-10 Examples of the aliphatic hydrocarbon ring include a C cyclopentane ring, a cyclohexane ring, and the like. 4-10 Examples of the ring structure containing the first atom include a cycloalkane ring. The ring structure containing the first atom may be a benzene ring or a heterocycle. The heterocycle may be an aromatic heterocycle or an aliphatic heterocycle.

[0047] The second ligand 22b may have a ring structure containing the first atom. For example, when the first ligand 22a has a benzene ring, the second ligand 22b may also have a benzene ring. In this case, the action of the second ligand 22b on the MOF1 is further promoted. As a result, the insulating material 10 is expected to exhibit a low dielectric tangent and high thermal stability.

[0048] When MOF1 is a ZIF, the second ligand 22b may include an imidazolate ligand. In this case, the effect of the second ligand 22b on MOF1 is further promoted. This is expected to result in the insulating material 10 exhibiting a low dielectric tangent and high thermal stability. In this disclosure, the imidazolate ligand refers to an imidazole-derived ligand that coordinates to a metal ion at the position of the nitrogen atom resulting from the removal of hydrogen from the NH group at the 1-position of the imidazole and at the position of the nitrogen atom at the 3-position.

[0049] The second ligand 22b may be an imidazolate ligand.

[0050] The imidazolate ligand may be represented by the following formula (1): The second ligand 22b may be represented by the following formula (1).

[0051]

[0052] In formula (1), R1 to R5 each independently represent a hydrogen atom, a hydroxy group, a carboxy group, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a halogen atom. The alkyl group may be linear or branched. The number of carbon atoms in the alkyl groups R1 to R5 each independently may be 1 to 8, 1 to 6, or 1 to 4. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. R1 to R5 each independently may represent an unsubstituted alkyl group. When the alkyl group has a substituent, the number of the substituents may be 1 to 6, 1 to 4, or 1 to 3. The number of carbon atoms in the aryl groups R1 to R5 each independently may be 6 to 14, or 6 to 10. Examples of aryl groups include phenyl and naphthyl groups. R1 to R5 may each independently be an unsubstituted phenyl group. The substituents on the alkyl and aryl groups may each independently be a halogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxy group, or the like. R1 to R5 and the halogen atoms of the substituents may be a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. R1 to R5 may each be a hydrogen atom.

[0053] When the imidazolate ligand is represented by formula (1), the action of the second ligand 22b on the MOF 1 is further promoted. Furthermore, the molecular mobility of the second ligand 22b is expected to decrease. As a result, the insulating material 10 is expected to have a low dielectric loss tangent.

[0054] The imidazolate ligand may be represented by the following formula (2): The second ligand 22b may be represented by the following formula (2).

[0055]

[0056] In formula (2), R6 to R8 each independently represent a hydrogen atom, a hydroxy group, a carboxy group, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a halogen atom. The alkyl group may be linear or branched. The number of carbon atoms in the alkyl groups R6 to R8 each independently may be 1 to 8, 1 to 6, or 1 to 4. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. R6 to R8 each independently may represent an unsubstituted alkyl group. When the alkyl group has a substituent, the number of the substituents may be 1 to 6, 1 to 4, or 1 to 3. The number of carbon atoms in the aryl groups R6 to R8 each independently may be 6 to 14, or 6 to 10. Examples of aryl groups include phenyl and naphthyl groups. R6 to R8 may each independently be an unsubstituted phenyl group. The substituents on the alkyl and aryl groups may each independently be a halogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxy group, or the like. The halogen atoms on R6 to R8 and the substituents may be fluorine, chlorine, bromine, or iodine atoms. R6 to R8 may each be a hydrogen atom.

[0057] When the imidazolate ligand is represented by formula (2), the action of the second ligand 22b on the MOF 1 is more promoted, which is expected to result in the insulating material 10 having a low dielectric tangent.

[0058] When MOF1 is a Zr-MOF particle, the second ligand 22b may include a carboxylate ligand. In this case, the action of the second ligand 22b on MOF1 is further promoted. This is expected to result in the insulating material 10 exhibiting a low dielectric tangent and high thermal stability.

[0059] The second ligand 22b may be a carboxylate ligand.

[0060] The carboxylate ligand may be represented by the following formula (3): The second ligand 22b may be represented by the following formula (3).

[0061]

[0062] In formula (3), R 11 From R 15 R each independently represents a hydrogen atom, a hydroxy group, a carboxy group, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a halogen atom. The alkyl group may be linear or branched. 11 From R 15 The number of carbon atoms in the alkyl groups may be, independently, 1 to 8, 1 to 6, or 1 to 4. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, and an n-octyl group. 11 From R 15 may each independently be an unsubstituted alkyl group. When the alkyl group has a substituent, the number of the substituents may be 1 to 6, 1 to 4, or 1 to 3. 11 From R 15 The number of carbon atoms in the aryl group may be, independently, 6 to 14, or 6 to 10. Examples of the aryl group include a phenyl group and a naphthyl group. 11 From R 15 may each independently be an unsubstituted phenyl group. The substituents on the alkyl group and aryl group may each independently be a halogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxy group, etc. 11 From R 15 The halogen atom of the substituent may be a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. 11 From R 15 may each be a hydrogen atom.

[0063] When the carboxylate ligand is represented by formula (3), the action of the second ligand 22b on MOF 1 is further promoted, which is expected to result in the insulating material 10 exhibiting a low dielectric tangent and high thermal stability.

[0064] Fig. 2A is a diagram showing an example of the structure of insulating material 10 in embodiment 1. Fig. 2A illustrates an example where second ligand 22b is represented by formula (3). Fig. 2B is a diagram showing the structure of MOF1 in Fig. 2A before the second ligand 22b is allowed to act on it. MOF1 shown in Fig. 2B is NU-1000.

[0065] In the insulating material 10 shown in Fig. 2A, a second ligand 22b is added to the MOF 1, thereby incorporating the second ligand 22b into the MOF 1. The insulating material 10 shown in Fig. 2A has a second mother framework 2b having a structure in which the second ligand 22b is added to the first mother framework 2a of the MOF 1.

[0066] The content x (%) of the second ligand 22b in the insulating material 10 is a value expressed as a percentage of the ratio of the amount of substance of the second ligand 22b to the total amount of substance of the ligands contained in the MOF 1. For example, when the molar abundance ratio of the first ligand 22a to the second ligand 22b contained in the MOF 1 is a:b, the content x is expressed by the following mathematical formula (I): x (%) = b / (a + b) × 100 ... formula (I)

[0067] In the above formula (I), 0.1≦x≦50 may be satisfied. In other words, the content x of the second ligand 22b in the insulating material 10 may be 0.1% or more and 50% or less. This configuration can further reduce the dielectric tangent of the insulating material 10. By setting the content x of the second ligand 22b in the insulating material 10 to 50% or less, it is possible to avoid the second ligand 22b not being allowed to act on the MOF1. If the second ligand 22b is not allowed to act on the MOF1, the crystal structure of the MOF1 may collapse, resulting in an increase in the dielectric constant, a decrease in thermal stability, and the like. However, as long as the desired dielectric properties can be exhibited, the content x of the second ligand 22b in the insulating material 10 is not particularly limited.

[0068] In the formula (I), the lower limit of x may be 0.7, and the upper limit of x may be 5.4.

[0069] [Manufacturing Method of Insulating Material] Next, a method for manufacturing the above-described insulating material 10 will be described. In the following, elements common to the above-described insulating material 10 will be denoted by the same reference numerals and description thereof will be omitted.

[0070] 3 is a flowchart showing an example of a method for producing insulating material 10 according to the first embodiment. The method for producing insulating material 10 has a dielectric loss tangent lower than that of MOF1 containing multiple first ligands 22a. The method includes contacting MOF1 with multiple first ligands 22a or multiple second ligands 22b having a structure different from that of each of the multiple first ligands 22a (step ST1), and performing at least one step selected from the group consisting of (a) exchanging at least a portion of the multiple first ligands 22a contained in MOF1 with multiple second ligands 22b, and (b) adding multiple first ligands 22a or multiple second ligands 22b to MOF1 (step ST2). This production method allows the production of insulating material 10 containing MOF1, in which a lower dielectric loss tangent is achieved due to a change in the coordination environment of the metal ions.

[0071] In step ST1, contacting MOF 1 with a plurality of first ligands 22 a or a second ligand 22 b having a structure different from each of the plurality of first ligands 22 a may mean contacting the plurality of first ligands 22 a with MOF 1. In step ST2, performing at least one selected from the group consisting of (a) exchanging at least a portion of the plurality of first ligands 22 a contained in MOF 1 with second ligands 22 b, and (b) adding a plurality of first ligands 22 a or second ligands 22 b to MOF 1 may mean (b) adding a plurality of first ligands 22 a to MOF 1. According to this production method, it is possible to produce insulating material 10 including MOF 1 in which a decrease in dielectric tangent is realized due to a change in the coordination environment of the metal ion caused by changing the coordination environment of the metal ion from a coordination unsaturated environment to a coordination saturated environment.

[0072] In the insulating material 10 produced by this production method, the number of atoms contained in the second ligand 22 b may be greater than the number of atoms contained in the first ligand 22 a, or the molecular weight of the second ligand 22 b may be greater than the molecular weight of the first ligand 22 a. With this configuration, the molecular mobility of the ligands is reduced, and the dielectric loss tangent of the insulating material 10 can be further reduced.

[0073] In step ST2, (a) exchanging at least a portion of the plurality of first ligands 22a contained in MOF1 with second ligands 22b may include exchanging a portion or all of the plurality of first ligands 22a contained in MOF1 with second ligands 22b. (a) exchanging at least a portion of the plurality of first ligands 22a contained in MOF1 with second ligands 22b may include exchanging a portion or all of the plurality of first ligands 22a contained in the first mother framework 2a of MOF1 with second ligands 22b to form a second mother framework 2b.

[0074] In step ST2, (b) adding a plurality of first ligands 22 a or second ligands 22 b to MOF1 may include adding second ligands 22 b to the first mother skeleton 2 a of MOF1 to form a second mother skeleton 2 b.

[0075] Step ST2 may involve both (a) exchanging at least a portion of the plurality of first ligands 22a contained in MOF1 with second ligands 22b, and (b) adding the plurality of first ligands 22a or second ligands 22b to MOF 1. Step ST2 may involve exchanging a portion or all of the plurality of first ligands 22a contained in the first mother skeleton 2a of MOF1 with second ligands 22b, and adding the second ligands 22b to the first mother skeleton 2a of MOF1 to form the second mother skeleton 2b.

[0076] [Method for controlling dielectric loss tangent of metal-organic framework] Next, a method for controlling the dielectric loss tangent of the metal-organic framework in embodiment 1 will be described. In the following, elements common to the above-described insulating material 10 will be denoted by the same reference numerals and description thereof will be omitted. Note that the MOF1 included in the above-described insulating material 10 corresponds to the MOF1 after the dielectric loss tangent has been reduced by the control method.

[0077] The method for controlling the dielectric dissipation factor of a metal-organic framework is a method for controlling the dielectric dissipation factor of a MOF 1, and includes (step S1) allowing second ligands 22 b having a structure different from the structures of each of the first ligands 22 a to act on the MOF 1 containing a plurality of first ligands 22 a, thereby reducing the dielectric dissipation factor of the MOF 1. The control method in the first embodiment is suitable for reducing the dielectric dissipation factor of the MOF 1.

[0078] In step S1, allowing the second ligand 22b to act on the MOF1 may include exchanging at least a portion of the multiple first ligands 22a contained in the MOF1 with the second ligand 22b. Exchanging at least a portion of the multiple first ligands 22a contained in the MOF1 with the second ligand 22b includes exchanging some or all of the multiple first ligands 22a contained in the MOF1 with the second ligand 22b. Allowing the second ligand 22b to act on the MOF1 may include exchanging some or all of the multiple first ligands 22a contained in the first mother framework 2a of the MOF1 with the second ligand 22b to form the second mother framework 2b.

[0079] In step S1, reacting the second ligand 22b with the MOF 1 may include adding the second ligand 22b to the MOF 1. Acting the second ligand 22b with the MOF 1 may include adding the second ligand 22b to the first mother framework 2a of the MOF 1 to form the second mother framework 2b.

[0080] In step S1, allowing the second ligand 22b to act on the MOF 1 may include both replacing some or all of the multiple first ligands 22a contained in the MOF 1 with the second ligand 22b and adding the second ligand 22b to the MOF 1. Allowing the second ligand 22b to act on the MOF 1 may include replacing some or all of the multiple first ligands 22a contained in the first mother skeleton 2a of the MOF 1 with the second ligand 22b and adding the second ligand 22b to the first mother skeleton 2a of the MOF 1 to form the second mother skeleton 2b.

[0081] Second Embodiment A filler according to a second embodiment contains the insulating material 10 of the first embodiment.

[0082] The filler in the second 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 second embodiment can improve chemical stability while suppressing an increase in the relative dielectric constant and the dielectric loss tangent.

[0083] The filler in the second embodiment can be produced by kneading, for example, the insulating 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.

[0084] 4 is a diagram showing a schematic configuration of a resin composition 20 according to an embodiment 3. The resin composition 20 contains, for example, a filler 22 and a curable resin 24.

[0085] Filler 22 includes insulating material 10 of embodiment 1. According to this embodiment, resin composition 20 exhibiting a low dielectric tangent and excellent heat resistance can be provided. As filler 22, insulating material 10 alone may be used, or other filler materials such as silica particles may be used in combination with insulating material 10.

[0086] 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.

[0087] 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.

[0088] (Embodiment 4) The prepreg in embodiment 4 comprises, for example, the resin composition 20 of embodiment 3 shown in FIG. 4 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] (Embodiment 5) Fig. 5 is a cross-sectional view of a resin-coated film 30 in embodiment 5. 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, it is possible to provide a resin-coated film 30 suitable for an insulating layer. The resin layer 32 is supported by the support film 34. In the example of Fig. 5, 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.

[0093] The resin layer 32 includes the resin composition 20 of the third embodiment shown in FIG. 4 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.

[0094] 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.

[0095] (Embodiment 6) Fig. 6 is a cross-sectional view of a resin-coated metal foil 40 in embodiment 6. The resin-coated metal foil 40 includes 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. According to this embodiment, it is possible to provide a resin-coated metal foil 40 suitable for electronic circuit components such as wiring boards. In the example of Fig. 6, the metal foil 44 is disposed on the surface of the resin layer 42. However, another layer, such as an adhesive layer, may be provided between the resin layer 42 and the metal foil 44.

[0096] The resin layer 42 includes the resin composition 20 of the third embodiment shown in FIG. 4 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.

[0097] 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.

[0098] Seventh Embodiment Fig. 7 is a cross-sectional view of a metal-clad laminate 50 according to a seventh 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 third embodiment shown in Fig. 4 or a cured product of the prepreg of the fourth 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.

[0099] The metal-clad laminate 50 is typically manufactured using the prepreg of the fourth embodiment. 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 the prepreg laminate. Examples of the metal foil 54 include copper foil and aluminum foil.

[0100] 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.

[0101] (Embodiment 8) Fig. 8 is a cross-sectional view of a wiring board 60 in embodiment 8. 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 3 shown in Fig. 4 or a cured product of the prepreg of embodiment 4. 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.

[0102] 7 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.

[0103] A new laminate may be formed by laminating the prepreg of the fourth embodiment 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.

[0104] Ninth Embodiment A sealing material for circuit boards in a ninth embodiment contains the resin composition 20 of the third embodiment.

[0105] The sealing material for circuit boards in the ninth 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 ninth embodiment can improve chemical stability while suppressing increases in the relative dielectric constant and the dielectric loss tangent.

[0106] Tenth Embodiment An adhesive material for a circuit board in a tenth embodiment includes the resin composition 20 of the third embodiment or a semi-cured product thereof.

[0107] The adhesive material for a circuit board in the tenth 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 tenth embodiment can improve chemical stability while suppressing increases in the relative dielectric constant and the dielectric loss tangent.

[0108] (Embodiment 11) A circuit board according to embodiment 11 includes an insulating layer containing a cured product of resin composition 20 according to embodiment 3 or a cured product of the prepreg according to embodiment 4. The circuit board according to embodiment 11 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.

[0109] FIG. 9 is a cross-sectional view showing an example of a circuit board according to the eleventh embodiment. The circuit board 1000 of FIG. 9 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. 9 is sometimes called an antenna-in-package (AiP). The circuit board 1000 is mounted on a motherboard 500 as a base for use.

[0110] 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.

[0111] As shown in FIG. 9 , 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.

[0112] 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 of the insulating layer 201 opposite to the surface (second surface 201b) of the insulating layer 201 that faces the wiring stack 102. The antenna element 202 is electrically connected to the wiring substrate 100, for example, via 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 via a connecting portion (not shown). For example, solder, conductive resin, or the like may be used as the connecting portion. As shown in FIG. 9 , the antenna substrate 200 may include a plurality of antenna elements 202. The plurality of antenna elements 202 may form an array.

[0113] 9, 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.

[0114] 9 , 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.

[0115] 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.

[0116] An insulating layer containing the cured product of the resin composition 20 of embodiment 3 or the cured product of the prepreg of embodiment 4 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.

[0117] 9, the circuit board 1000 may further include an antenna element 202 capable of transmitting a high-frequency signal. 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 a high-frequency signal.

[0118] The circuit board in embodiment 11 is not limited to the circuit board 1000 shown in FIG. 9 . An insulating layer containing a cured product of the resin composition 20 of embodiment 3 or a cured product of the prepreg of embodiment 4 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 3 or a cured product of the prepreg of embodiment 4 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 3 or a cured product of the prepreg of embodiment 4 can be used as an insulating layer for forming a build-up layer of a multilayer printed wiring board.

[0119] Modified examples of the circuit board will be described below. In the following, elements common to the circuit board 1000 shown in Fig. 9 will be denoted by the same reference numerals and description thereof will be omitted.

[0120] (Modification 1) Fig. 10A is a cross-sectional view showing an example of a circuit board 2000 in Modification 1. Fig. 10B is an enlarged view of part XB in Fig. 10A. Circuit board 2000 has an insulating layer containing a cured product of resin composition 20 of embodiment 3 or a cured product of the prepreg of embodiment 4.

[0121] 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. 10A is sometimes called an FC-BGA (Flip Chip-Ball-Grid Array) substrate. The circuit board 2000 is mounted on a motherboard 500 as a base for use.

[0122] 10A and 10B , 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 layer 152.

[0123] As shown in FIG. 10A , 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.

[0124] 10A , 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 400b.

[0125] An insulating layer including the cured product of resin composition 20 of Embodiment 3 or the cured product of the prepreg of Embodiment 4 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 3 or the cured product of the prepreg of Embodiment 4 may be insulating layer 152a of package substrate 105. An insulating layer including the cured product of resin composition 20 of Embodiment 3 or the cured product of the prepreg of Embodiment 4 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.

[0126] 11 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 3 or a cured product of the prepreg according to Embodiment 4, and is therefore suitable for high frequencies.

[0127] 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. 10A. For the configuration of the package substrate 105 of the circuit board 3000, refer to FIG. 10B. The intermediate layer 106 is sometimes called an organic interposer or an RDL interposer. The circuit board 3000 shown in FIG. 11 is sometimes called a 2D or 3D package. The circuit board 3000 is mounted on a motherboard 500 as a base for use.

[0128] 11 , 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.

[0129] 11 , 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.

[0130] 11 , 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.

[0131] The insulating layer including the cured product of resin composition 20 of Embodiment 3 or the cured product of the prepreg of Embodiment 4 can be applied to both insulating layer 152 a 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 3 or the cured product of the prepreg of Embodiment 4 may be at least one selected from the group consisting of insulating layer 152 a 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 3 or the cured product of the prepreg of Embodiment 4 is suitable for reducing the dielectric dissipation factor of a dielectric material, and therefore, by applying it as insulating layer 152 a of package substrate 105 and / or insulating layer 161 of intermediate layer 106, a circuit board 3000 suitable for high frequencies can be provided.

[0132] 12 is a cross-sectional view showing an example of a circuit board 4000 in Modification 3. Circuit board 4000 includes an insulating layer containing a cured product of resin composition 20 of Embodiment 3 or a cured product of the prepreg of Embodiment 4, and is therefore suitable for high frequencies.

[0133] 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. 12 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.

[0134] 12, 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.

[0135] 12 , 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.

[0136] An insulating layer including the cured product of resin composition 20 of Embodiment 3 or the cured product of the prepreg of Embodiment 4 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 3 or the cured product of the prepreg of Embodiment 4 may be insulating layer 171 included in rewiring layer 107. An insulating layer including the cured product of resin composition 20 of Embodiment 3 or the cured product of the prepreg of Embodiment 4 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.

[0137] (Other Embodiments) (Additional Notes) The above description of the embodiments discloses the following techniques.

[0138] (Technology 1) A method for producing an insulating material having a dielectric loss tangent lower than that of a metal-organic framework containing a plurality of first ligands, the method comprising: bringing the metal-organic framework into contact with the plurality of first ligands or a second ligand having a structure different from each of the plurality of first ligands; and performing at least one selected from the group consisting of: (a) exchanging at least a portion of the plurality of first ligands contained in the metal-organic framework with the second ligand; and (b) adding the plurality of first ligands or the second ligand to the metal-organic framework.

[0139] According to the method for producing an insulating material of Technology 1, it is possible to produce an insulating 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.

[0140] The method for producing an insulating material according to Technology 1 may include: bringing the metal-organic framework into contact with a second ligand having a structure different from each of the plurality of first ligands; and performing at least one selected from the group consisting of: (a) exchanging at least a part of the plurality of first ligands contained in the metal-organic framework with the second ligand; and (b) adding the second ligand to the metal-organic framework.

[0141] (Technology 2) The method for manufacturing an insulating material according to Technology 1, wherein the number of the one or more atoms contained in the second ligand is greater than the number of the one or more atoms contained in each of the plurality of first ligands, or the molecular weight of the second ligand is greater than the molecular weight of each of the plurality of first ligands.

[0142] According to this configuration, the molecular mobility of the ligand is reduced, and the dielectric loss tangent of the insulating material can be further reduced.

[0143] (Technology 3) An insulating material comprising a metal-organic framework, wherein the metal-organic framework includes a plurality of first ligands and a plurality of second ligands, and wherein a structure of each of the plurality of first ligands is different from a structure of the second ligand.

[0144] The insulating material of technique 3 can have a lower dielectric tangent than a metal-organic framework that includes only a plurality of first ligands as ligands.

[0145] (Technology 4) The insulating material according to Technology 3, wherein the number of the one or more atoms contained in the second ligand is greater than the number of the one or more atoms contained in each of the plurality of first ligands.

[0146] With an insulating material having such a configuration, a further reduction in the dielectric loss tangent can be achieved.

[0147] (Technology 5) The insulating material according to Technology 3 or 4, wherein the molecular weight of the second ligand is greater than the molecular weight of each of the plurality of first ligands.

[0148] With an insulating material having such a configuration, a further reduction in the dielectric loss tangent can be achieved.

[0149] (Technology 6) The insulating material according to any one of Technologies 3 to 5, wherein the metal organic framework further includes a plurality of metal ions, each of the plurality of first ligands includes one or more first atoms coordinated to a corresponding metal ion among the plurality of metal ions, and the second ligand includes the one or more first atoms.

[0150] With an insulating material having such a configuration, a further reduction in the dielectric loss tangent can be achieved.

[0151] (Technology 7) The insulating material according to Technology 6, wherein the number of the one or more first atoms contained in the second ligand is equal to the number of the one or more first atoms contained in each of the plurality of first ligands.

[0152] With an insulating material having such a configuration, a further reduction in the dielectric loss tangent can be achieved.

[0153] (Technology 8) The insulating material according to Technology 6 or 7, wherein each of the plurality of first ligands has a ring structure including the one or more first atoms, and the second ligand has the ring structure.

[0154] With an insulating material having such a configuration, a further reduction in the dielectric loss tangent can be achieved.

[0155] (Technology 9) A filler comprising the insulating material according to any one of Technologies 3 to 8.

[0156] According to the filler of Technology 9, a filler exhibiting a low dielectric tangent can be provided.

[0157] (Technology 10) A resin composition comprising the filler according to Technology 9.

[0158] According to the resin composition of Technique 10, a resin composition exhibiting a low dielectric tangent can be provided.

[0159] (Technology 11) A prepreg comprising the resin composition according to Technology 10 or a semi-cured product of the resin composition.

[0160] According to the prepreg of Technology 11, a prepreg exhibiting a low dielectric tangent can be provided.

[0161] (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.

[0162] According to the resin-coated film of Technique 12, a resin-coated film exhibiting a low dielectric loss tangent can be provided.

[0163] (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.

[0164] 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.

[0165] (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.

[0166] According to the metal-clad laminate of Technology 14, it is possible to provide a metal-clad laminate exhibiting a low dielectric tangent.

[0167] (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.

[0168] According to the wiring board of Technology 15, it is possible to provide a wiring board that exhibits a low dielectric loss tangent.

[0169] (Technology 16) A sealing material for circuit boards, comprising the resin composition according to Technology 10.

[0170] 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.

[0171] (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.

[0172] 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.

[0173] (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.

[0174] 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.

[0175] (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.

[0176] The circuit board of Technology 19 is suitable for high frequencies.

[0177] (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.

[0178] The circuit board of Technology 20 is suitable for high frequencies.

[0179] 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.

[0180] Example 1 MOF ZIF-8 particles (manufactured by Aldrich, product name: Basolite Z1200) were used as the MOF.

[0181] [Second Ligand] 5,6-dimethylbenzimidazolate was used as the second ligand.

[0182] Example 1-a Synthesis of Insulating Material 1.000 g of ZIF-8 particles were mixed with 140 mL of methanol and stirred for 30 minutes to obtain a first solution. Next, 0.2 g of 5,6-dimethylbenzimidazolate was dissolved in 60 mL of methanol to obtain a second solution. The second solution was added to the first solution, and 0.7 g of triethylamine was then added to the first solution. The mixture was stirred under reflux at 60°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. Through this process, particles of the insulating material of Example 1-a were obtained.

[0183] [Confirmation of the Presence of Second Ligand] The presence of a second ligand in the insulating material of Example 1-a can be confirmed by the following: 1 The ratio was determined from the ratio of the integral values ​​of the peaks corresponding to each functional group in the profile obtained from H nuclear magnetic resonance (NMR) (600 MHz, DMSO-d). The NMR instrument used was a JEOL JNM ECZ600R. The sample used for NMR measurement was a solution prepared by dissolving particles of the insulating material of Example 1-a in a mixed solution of deuterium chloride (20 wt % deuterium oxide solution) and DMSO-d.

[0184] FIG. 13 shows the insulating material of Example 1-a. 113 shows the H-NMR spectrum. In FIG. 13, the horizontal axis indicates the chemical shift (ppm), and the vertical axis indicates the relative intensity of the signal. Note that since FIG. 13 shows the position of each peak, the scale on the vertical axis is omitted. As shown in FIG. 13, in the insulating material of Example 1-a, a peak at 2.43 ppm corresponding to the protons on the methyl group of 2-methylimidazole, a peak at 7.25 ppm corresponding to the protons on the 4th and 5th carbons, a peak at 2.22 ppm corresponding to the protons on the two methyl groups of 5,6-dimethylbenzimidazole, and a peak at 7.49 ppm corresponding to the protons on the 6th and 7th carbons were observed. This confirmed the presence of a second ligand in the structure of the ZIF-8 particle. The obtained 1 The content of the second ligand in the insulating material of Example 1-a was calculated from the H-NMR spectrum, and the results are shown in Table 1.

[0185] Example 1-b [Synthesis of Insulating Material] 1.000 g of ZIF-8 particles were mixed with 140 mL of methanol and stirred for 30 minutes to obtain a first solution. Next, 1.000 g of 5,6-dimethylbenzimidazolate was dissolved in 60 mL of methanol to obtain a second solution. The second solution was added to the first solution, and 0.7 g of triethylamine was then added to the first solution. The mixture was then stirred under reflux at 60°C for 16 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 process, particles of the insulating material of Example 1-b were obtained.

[0186] [Confirmation of the Presence of Second Ligand] The presence of the second ligand in the insulating material of Example 1-b was confirmed by the same method as in Example 1-a. 1 The obtained product was confirmed by H-NMR spectrum. 1 The content of the second ligand in the insulating material of Example 1-b was calculated from the H-NMR spectrum, and the results are shown in Table 1.

[0187] Example 1-c Synthesis of Insulating Material 1.000 g of ZIF-8 particles were mixed with 140 mL of methanol and stirred for 30 minutes to obtain a first solution. Next, 1.000 g of 5,6-dimethylbenzimidazolate was dissolved in 60 mL of methanol to obtain a second solution. The second solution was added to the first solution, and 0.7 g of triethylamine was then added to the first solution. The mixture was stirred under reflux at 60°C for 48 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 process, particles of the insulating material of Example 1-c were obtained.

[0188] [Confirmation of the presence of a second ligand] In the insulating material of Example 1-c, the presence of a second ligand in the ZIF-8 particles was confirmed by the same method as in Example 1-a. 1 The obtained product was confirmed by H-NMR spectrum. 1 The content of the second ligand in the insulating material of Example 1-c was calculated from the H-NMR spectrum, and the results are shown in Table 1.

[0189] Example 2 [MOF] The same ZIF-8 particles as in Example 1 were used as the MOF.

[0190] [Second Ligand] Benzimidazolate was used as the second ligand.

[0191] [Synthesis of Insulating Material] 1.000 g of ZIF-8 particles were mixed with 140 mL of methanol and stirred for 30 minutes to obtain a first solution. Next, 0.808 g of benzimidazolate was dissolved in 60 mL of methanol to obtain a second solution. The second solution was added to the first solution, and then 0.7 g of triethylamine was added to the first solution. The mixture was then stirred under reflux at 60°C for 48 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 process, particles of the insulating material of Example 2 were obtained.

[0192] [Confirmation of the presence of the second ligand] In the insulating material of Example 2, the presence of the second ligand in the ZIF-8 particles was confirmed by the same method as in Example 1-a. 1 This was confirmed by H-NMR spectroscopy.

[0193] FIG. 14 shows the insulating material of Example 2. 1 14 shows the H-NMR spectrum. As shown in Fig. 14, in the insulating material of Example 2, a peak at 2.43 ppm corresponding to the protons on the methyl group of 2-methylimidazole, a peak at 7.25 ppm corresponding to the protons on the 4th and 5th carbons, and peaks from 7.47 ppm to 7.75 ppm corresponding to the protons on the 6th, 7th, 8th and 9th carbons of benzimidazole were observed. This confirmed the presence of a second ligand in the structure of the ZIF-8 particle. 1 From the H-NMR spectrum, the content of the second ligand in the insulating material of Example 2 was calculated. The results are shown in Table 1.

[0194] Example 3 [MOF] The same ZIF-8 particles as in Example 1 were used as the MOF.

[0195] [Second Ligand] 2-ethylimidazolate was used as the second ligand.

[0196] [Synthesis of Insulating Material] 1.000 g of ZIF-8 particles were mixed with 140 mL of methanol and stirred for 30 minutes to obtain a first solution. Next, 0.658 g of 2-ethylimidazolate was dissolved in 60 mL of methanol to obtain a second solution. The second solution was added to the first solution, and then 0.7 g of triethylamine was added to the first solution. The mixture was then stirred under reflux at 60°C for 48 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 process, particles of the insulating material of Example 3 were obtained.

[0197] [Confirmation of the presence of the second ligand] In the insulating material of Example 3, the presence of the second ligand in the ZIF-8 particles was confirmed by the same method as in Example 1-a. 1This was confirmed by H-NMR spectroscopy.

[0198] FIG. 15 shows the insulating material of Example 3. 1 15 shows the H-NMR spectrum. As shown in Fig. 15, in the insulating material of Example 3, a peak at 2.43 ppm corresponding to the protons on the methyl group of 2-methylimidazole, a peak at 7.25 ppm corresponding to the protons on the 4th and 5th carbons, and peaks at 1.13 ppm and 2.79 ppm corresponding to the protons on the two ethyl groups of 2-ethylimidazolate were observed. This confirmed the presence of a second ligand in the structure of the ZIF-8 particles. 1 From the H-NMR spectrum, the content of the second ligand in the insulating material of Example 3 was calculated. The results are shown in Table 1.

[0199] Example 4 [MOF] NU-1000 particles were used as the MOF. NU-1000 particles were synthesized by the method described in "Timur Islamoglu, Ken-ichi Otake, Peng Li, Cassandra T. Buru, Aaron W. Peters, Isil Akpinar, Sergio J. Garibay and Omar K. Farha, CrystEngComm, 2018, vol. 20, 5913-5918." The crystalline structure of the synthesized particles was confirmed by powder X-ray diffraction measurement. A RINT2000 manufactured by Rigaku Corporation was used as the powder X-ray diffractometer. Cu-Kα radiation (λ = 1.541 Å) was used as the X-ray source for powder X-ray diffraction. Figure 16 shows an example of the X-ray diffraction pattern of the synthesized particles, along with a simulated X-ray diffraction pattern of NU-1000 predicted from the crystal structure. In Figure 16, the horizontal axis represents the diffraction angle (2θ) and the vertical axis represents the X-ray intensity. Note that the scale on the vertical axis is omitted in Figure 16 because it is a diagram for comparing the trends of the two X-ray diffraction patterns. Since the trends of the two X-ray diffraction patterns are similar, it was determined that the crystal structure of the synthesized particles was NU-1000.

[0200] [Second Ligand] Trifluoroacetic acid was used as the second ligand.

[0201] [Synthesis of Insulating Material] The insulating material particles of Example 4 were synthesized by the method described in Non-Patent Document 2.

[0202] [Confirmation of the presence of a second ligand] The presence of a second ligand in the NU-1000 particles in the insulating material of Example 4 can be confirmed by the following: 1 This was determined by comparing the profile of the insulating material of Example 4 obtained from H nuclear magnetic resonance (NMR) (600 MHz) with the profile of the NU-1000 particles. The NMR device used was a JNM ECZ600R manufactured by JEOL. The sample used for NMR measurement was prepared by dissolving particles of the insulating material of Example 4 in a mixed solution of sodium deuterium hydroxide (40 wt % deuterium oxide solution) and heavy water.

[0203] Figure 17 shows the distribution of NU-1000 particles. 1 1H-NMR spectrum of the insulating material of Example 4. 1 The H-NMR spectrum is shown in Figure 17. In Figure 17, a peak at 8.46 ppm was confirmed, which corresponds to formic acid bound to Zr oxide clusters present in the NU-1000 structure. On the other hand, in Figure 18, no peak was detected near 8.46 ppm, confirming that the formic acid bound to NU-1000 had disappeared. From this, it was determined that the second ligand had acted on the NU-1000 particles, modifying them. 1 From the H-NMR spectrum, the content of the second ligand in the insulating material of Example 4 was calculated. The results are shown in Table 1.

[0204] Example 5 [MOF] The same NU-1000 particles as in Example 4 were used as the MOF.

[0205] [Second Ligand] Benzoic acid was used as the second ligand.

[0206] [Synthesis of Insulating Material] The insulating material particles of Example 5 were synthesized by the method described in Non-Patent Document 2, as in Example 4.

[0207] [Confirmation of the presence of a second ligand] As in Example 4, the presence of a second ligand in the NU-1000 particles in the insulating material particles of Example 5 was confirmed by the 1 H-NMR spectrum and NU-1000 particles 1 This was confirmed by comparing with the H-NMR spectrum (Figure 17).

[0208] FIG. 19 shows the insulating material of Example 5. 1 19 shows the H-NMR spectrum. In FIG. 19, no peak was detected around 8.46 ppm, confirming that the formic acid bound to NU-1000 had disappeared. From this, it was determined that the second ligand had acted on the NU-1000 particles, modifying the NU-1000 particles. 1 From the H-NMR spectrum, the content of the second ligand in the insulating material of Example 5 was calculated. The results are shown in Table 1.

[0209] Comparative Example 1 The ZIF-8 particles used in Examples 1 to 3 were used as the material particles for Comparative Example 1.

[0210] Comparative Example 2 The NU-1000 particles used in Examples 4 and 5 were used as the material particles in Comparative Example 2. 1 This corresponds to the H-NMR spectrum.

[0211] The dielectric loss tangent of each of the particles obtained in Examples 1 to 5 and Comparative Examples 1 and 2 was evaluated based on the method described below.

[0212] [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. When the MOF was ZIF-8, each particle was pretreated under vacuum (10 Pa or less), at 200°C, for 1 hour. When the MOF was NU-1000, each particle was pretreated under vacuum (10 Pa or less), at 120°C, for 12 hours. The results are shown in Table 1.

[0213] [Evaluation of Dielectric Loss Tangent of Particles Before and After the Action of Second Ligand] Using a cavity resonance method at a frequency of 1 GHz, the dielectric loss tangent of each particle before and after the action of the second ligand was determined by the following method. The cavity resonator used was an MS46122B manufactured by AET Corporation. In the measurement, when the MOF was ZIF-8, the particles were pretreated under conditions of vacuum (10 Pa or less), 200°C, and 1 hour, and then the particles were packed into a sample tube under a N2 atmosphere without being exposed to the atmosphere, and the measurement was performed. 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 by the packing fraction of the sample tube. The packing fraction 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 as the density (0.921 g / cm) calculated from the crystal structure. 3 ) was used. The true density of the particles after the action of the second ligand was determined from the following formulas (X1) and (Y1). The porosity of the ZIF-8 particles was set to 50%. The results are shown in Table 1. True density of the particles after the action of the second ligand = (density calculated from the crystal structure of the ZIF-8 particle) ÷ {(porosity of the ZIF-8 particle × 0.01) × (pore maintenance rate) × 0.01} ... formula (X1) Porosity maintenance rate = (pore volume of the particle after the action of the second ligand) ÷ (pore volume of the ZIF-8 particle before the action of the second ligand) ... formula (Y1)

[0214] When the MOF was NU-1000, the particles were pretreated under conditions of 120°C under vacuum (10 Pa or less) for 12 hours, and then the particles were packed into a sample tube within 5 minutes of exposure to the atmosphere, and measurements were performed. The packing fraction of the sample tube was calculated from the true density of the NU-1000 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 fraction 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 NU-1000 particles. The true density of the NU-1000 particles was determined using the density (0.486 / cm) calculated from the crystal structure. 3) was used. The true density of the particles after the action of the second ligand was determined from the following formulas (X2) and (Y2). The porosity of the NU-1000 particles was set to 68%. The results are shown in Table 1. True density of the particles after the action of the second ligand = (density calculated from the crystal structure of the NU-1000 particles) ÷ {(porosity of the NU-1000 particles × 0.01) × (pore maintenance rate) × 0.01} ... formula (X2) Porosity maintenance rate = (pore volume of the particles after the action of the second ligand) ÷ (pore volume of the NU-1000 particles before the action of the second ligand) ... formula (Y2)

[0215]

[0216] <<Discussion>> As shown in Table 1, the dielectric dissipation factor of the insulating materials of Examples 1-a to 1-3 decreased compared to that of the ZIF-8 particles of Comparative Example 1 in both air and N2 atmospheres. From these results, it can be concluded that the dielectric dissipation factor decreased due to the effect of the second ligand. The dielectric dissipation factor of a material can be affected by humidity and / or exposure time. Therefore, the decrease in the dielectric dissipation factor of the insulating materials of Examples 1-a to 1-3 even in an N2 atmosphere, where moisture absorption is not an issue, supports the fact that the dielectric dissipation factor decreased due to the properties of the material itself. Furthermore, the fact that the insulating materials of Examples 1-a to 1-3 contain a second ligand and have a decreased dielectric dissipation factor suggests that the first ligand in the ZIF-8 in the insulating material has been replaced with a second ligand and / or that a second ligand has been added to the ZIF-8.

[0217] As shown in Table 1, the dielectric loss tangents in the air of the insulating materials of Examples 4 to 5 were lower than the dielectric loss tangent in the air of the NU-1000 particles of Comparative Example 2. From this result, it can be determined that the dielectric loss tangent was lowered due to the action of the second ligand. Note that the insulating materials of Examples 4 to 5 contained a second ligand, and the lowered dielectric loss tangents suggest that the first ligand contained in NU-1000 in the insulating materials was replaced with a second ligand and / or a second ligand was added to NU-1000.

[0218] As described above, the insulating materials of Examples 1-a to 5 exhibited low dielectric loss tangents. Therefore, by using such insulating 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.

[0219] In Examples 1-a to 3, ZIF-8 was used as the MOF, but even if ZIF such as ZIF-4, ZIF-7, ZIF-12, ZIF-67, ZIF-90, or ZIF-412 is used instead of ZIF-8, it is estimated that the dielectric loss tangent will decrease in the same manner as in Examples 1-a to 3. In addition, in Examples 4 and 5, NU-1000 was used as the MOF, but even if Zr-MOFs such as UiO-66, UiO-67, UiO-68, NU-1103, MOF-808, PCN-224, DUT-52, BUT-30, or MIL-140 are used instead of NU-1000, it is estimated that the dielectric loss tangent will decrease in the same manner as in Examples 4 and 5. Furthermore, even when a MOF other than ZIF and Zr-MOF is used as the MOF, it is estimated that the dielectric loss tangent will decrease as in Examples 1-a to 5. This is because the insulating material of the present disclosure achieves a decrease in the dielectric loss tangent by allowing a second ligand having a structure different from that of the first ligand to act on an MOF containing multiple first ligands.

[0220] 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.

[0221] The insulating material of the present disclosure can realize fillers with low dielectric tangents, and is therefore suitable for applications such as wiring boards for electronic devices used in high-capacity communications.

[0222] 1 Metal-organic framework (MOF) 2a First mother skeleton 2b Second mother skeleton 21 Metal ion 22a First ligand 22b Second ligand 10 Insulating 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 DESCRIPTION OF SYMBOLS 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 an insulating material having a dielectric tangent lower than that of a metal-organic framework containing a plurality of first ligands, the method comprising: contacting the metal-organic framework with the plurality of first ligands, or a second ligand having a structure different from each of the structures of the plurality of first ligands; and performing at least one selected from the group consisting of: (a) exchanging at least a portion of the plurality of first ligands contained in the metal-organic framework with the second ligand; and (b) adding the plurality of first ligands or the second ligand to the metal-organic framework.

2. A method for manufacturing an insulating material as described in claim 1, wherein the number of one or more atoms contained in the second ligand is greater than the number of one or more atoms contained in each of the plurality of first ligands, or the molecular weight of the second ligand is greater than the molecular weight of each of the plurality of first ligands.

3. An insulating material comprising a metal organic framework, the metal organic framework comprising a plurality of first ligands and a second ligand, the structure of each of the plurality of first ligands being different from the structure of the second ligand.

4. The insulating material according to claim 3, wherein the number of the one or more atoms contained in the second ligand is greater than the number of the one or more atoms contained in each of the plurality of first ligands.

5. The insulating material according to claim 3, wherein the molecular weight of the second ligand is greater than the molecular weight of each of the plurality of first ligands.

6. The insulating material according to claim 3, wherein the metal organic framework further comprises a plurality of metal ions, each of the plurality of first ligands comprises one or more first atoms coordinated to a corresponding metal ion among the plurality of metal ions, and the second ligand comprises the one or more first atoms.

7. The insulating material according to claim 6, wherein the number of said one or more first atoms contained in said second ligand is equal to the number of said one or more first atoms contained in each of said plurality of first ligands.

8. The insulating material according to claim 6, wherein each of the plurality of first ligands has a ring structure including the one or more first atoms, and the second ligand has the ring structure.

9. A filler comprising the insulating 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 said redistribution layer, said redistribution layer including said insulating layer.

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