Films and printed circuit boards for electronic devices

Abstract

To provide a film for electronic apparatus that is lower in dielectric constant and dielectric loss tangent than conventional materials and is also excellent in thermostability.SOLUTION: A film for electronic apparatus contains a compound represented by formula (1). In a wide angle X-ray scattering profile, a first region with a scattering vector q of 2 nm -1 or more and 8 nm -1 or less includes at least one peak and a second region with a scattering vector q of 10 nm -1 or more and 20 nm -1 or less includes at least one peak, where R1 and R2 or R3 and R4 each denote one independently selected from a hydrogen atom and a substituted or unsubstituted C1-30 hydrocarbon group or together form an alkylidene group.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a film for electronic devices and a printed circuit board. [Background technology]

[0002] Printed circuit boards are widely used for applications such as high-frequency devices. A printed circuit board typically has a flat plate-like structure in which an insulating substrate material, copper foil, and a covering material are laminated, and the substrate material and covering material are mainly composed of a resin material. When such a printed circuit board is mounted in an electronic device, various elements are connected to the wiring (copper foil) provided on the printed circuit board by a method such as soldering.

[0003] When soldering is performed during the mounting stage as described above, the printed circuit board is temporarily exposed to high temperatures (e.g., 250°C). Therefore, the resin material used for the printed circuit board is required to have a certain level of heat resistance. Furthermore, when the printed circuit board is used in a high-frequency device, the communication performance of the device is determined by the electrical properties of the resin materials used as the board material and the covering material. Specifically, the lower the dielectric constant and dielectric loss tangent of the resin material, the more likely it is that the communication performance will improve. Liquid crystal polymers, for example, are used as materials that can satisfy these heat resistance and electrical properties (Patent Document 1, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-65061 [Patent Document 2] International Publication No. 2020 / 179443 Summary of the Invention [Problem to be solved by the invention]

[0005] However, as demand for high-speed communications increases, the electrical properties of liquid crystal polymers have not always met the performance requirements for printed circuit boards used in high-frequency devices.

[0006] Therefore, there is a need to develop a film for electronic devices that has a lower dielectric constant and dielectric loss tangent than conventional materials and is excellent in heat resistance. [Means for solving the problem]

[0007] The film for electronic devices according to the present invention contains a compound represented by formula (1), and in a wide-angle X-ray scattering profile, the scattering vector q is 2 nm -1 8nm or more -1 The first region below, and 10 nm -1 More than 20nm -1 The compound is characterized by having at least one peak in each of the following second regions: 1 and R 2 are independently selected from the group consisting of a hydrogen atom and a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, or together form an alkylidene group, and R 3 and R 4 are each independently selected from the group consisting of a hydrogen atom and a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, or together form an alkylidene group. [ka]

[0008] The printed circuit board according to the present invention is characterized by including the above-mentioned film for electronic devices.

[0009] The compound represented by formula (1) exhibits a low dielectric constant and a low dielectric loss tangent derived from the polynorbornene skeleton. Furthermore, the wide-angle X-ray scattering profile indicates that the polynorbornene skeleton is more densely packed than conventional polynorbornenes, which allows the compound represented by formula (1) to exhibit higher heat resistance than conventional materials containing polynorbornene. These properties of the compound represented by formula (1) enable the realization of films for electronic devices that have lower dielectric constants and dielectric loss tangents than conventional materials and excellent heat resistance, as well as printed circuit boards including such films.

[0010] The compound represented by formula (1) has a linear expansion coefficient equivalent to that of conventionally known polynorbornenes and a lower Young's modulus than conventionally known polynorbornenes. These properties make it possible to provide a film for electronic devices and a printed circuit board including the same, which are excellent in flexibility and flex resistance.

[0011] Preferred embodiments of the present invention will be described below, but the scope of the present invention is not limited to the preferred embodiments described below.

[0012] In one embodiment of the film for electronic devices according to the present invention, the compound is represented by the formula (1), 1 , R 2 , R 3 , and R 4 and preferably contain a monomer unit in which all of

[0013] According to this configuration, the film for electronic devices according to the present invention can be provided using unsubstituted norbornene, which is relatively easily available, as a raw material.

[0014] In one embodiment of the film for electronic devices according to the present invention, the compound is represented by the formula (1), 2 , R 3 , and R 4 are all hydrogen atoms, and R 1is any one selected from the group consisting of an alkyl group, an alkenyl group, and a cycloalkyl group having 20 or less carbon atoms, and 3 and R 4 are all hydrogen atoms, and R 1 and R 2 and a monomer unit which together form an alkylidene group having 20 or less carbon atoms.

[0015] This configuration tends to provide the film for electronic devices with heat resistance, flexibility, and bending resistance at levels particularly suitable for printed circuit boards.

[0016] In one embodiment, the film for electronic devices according to the present invention preferably has at least two peaks in the first region.

[0017] According to this configuration, it is possible to provide a film for electronic devices that is particularly excellent in heat resistance.

[0018] In one embodiment of the film for electronic devices according to the present invention, the compound is a copolymer represented by formula (2), and m / (n+m) is preferably 0.05 or more and 1.0 or less. [ka]

[0019] This configuration tends to provide the film for electronic devices with heat resistance, flexibility, and bending resistance at levels particularly suitable for printed circuit boards.

[0020] In one embodiment of the film for electronic devices according to the present invention, the compound represented by formula (1) preferably has a glass transition temperature of 260°C or higher as measured by dynamic viscoelasticity measurement in accordance with JIS K 7244:1998 under conditions of a heating rate of 5°C / min and a frequency of 1 Hz.

[0021] This configuration tends to provide the film for electronic devices with heat resistance at a level particularly suitable for printed circuit boards.

[0022] In one embodiment of the film for electronic devices according to the present invention, the compound represented by formula (1) preferably has a linear expansion coefficient, specified as a slope between 50 and 100°C, of ​​100 ppm or less in thermomechanical analysis under conditions of a tensile load of 10 mN, a temperature range of 25 to 250°C, and a heating rate of 5°C / min.

[0023] According to this configuration, when the film for an electronic device according to the present invention is bonded to a copper foil, peeling between the film and the copper foil is suppressed.

[0024] In one embodiment of the film for electronic devices according to the present invention, the compound represented by formula (1) preferably has a relative dielectric constant of 3.0 or less when measured at a frequency of 10 GHz according to JIS C 2565-1992.

[0025] According to this configuration, the film for electronic devices according to the present invention can be suitably used for high frequency devices.

[0026] In one embodiment of the film for electronic devices according to the present invention, the compound represented by formula (1) preferably has a dielectric loss tangent of 0.003 or less, measured at a frequency of 10 GHz according to JIS C 2565-1992.

[0027] According to this configuration, the film for electronic devices according to the present invention can be suitably used for high frequency devices.

[0028] In one embodiment of the film for electronic devices according to the present invention, the content of the compound represented by formula (1) is preferably 40% or more by weight.

[0029] According to this configuration, the properties of the compound represented by formula (1) can be strongly reflected in the mechanical and electrical properties of the film for electronic devices, and the film is likely to exhibit properties suitable for electronic devices.

[0030] In one embodiment, the film for electronic devices according to the present invention further contains a filler having a relative dielectric constant of 10 or less, and the content of the filler is preferably 50% or less by weight.

[0031] This configuration makes it possible to improve the physical properties of the film (for example, the linear expansion coefficient) by adding a filler while maintaining the properties of the compound represented by formula (1).

[0032] In one embodiment, the film for electronic devices according to the present invention preferably comprises a main material formed into a film shape and the compound represented by formula (1) dispersed in the main material.

[0033] According to this construction, the properties of the compound represented by formula (1) can be reflected without significantly changing the construction of conventional films for electronic devices.

[0034] In one embodiment, the film for electronic devices according to the present invention preferably has particles dispersed in the main material, and the particles preferably contain the compound.

[0035] This configuration makes it easy to disperse the compound represented by formula (1) in the main material.

[0036] In one embodiment, the film for electronic devices according to the present invention comprises an adhesive layer having adhesive properties to metals and an insulating layer at least partially covering the adhesive layer, and it is preferable that the main material is a material having adhesive properties to metals, and that the compound represented by formula (1) is dispersed in the main material in the adhesive layer.

[0037] According to this configuration, the dielectric constant and dielectric loss tangent of the adhesive layer can be reduced by reflecting the electrical properties of the compound represented by formula (1), which has traditionally been difficult to achieve in adhesive layers, and this can reduce the dielectric constant and dielectric loss tangent of the entire film.

[0038] In one embodiment, the film for electronic devices according to the present invention comprises an adhesive layer having adhesion to metals and an insulating layer at least partially covering the adhesive layer, and the main material is an insulating material, and it is preferable that the compound represented by formula (1) is dispersed in the main material in the insulating layer.

[0039] According to this configuration, the electrical properties of the insulating layer can be improved without changing or with minimal change to the basic design of an existing film for electronic devices having an insulating layer and an adhesive layer.

[0040] Further features and advantages of the present invention will become more apparent from the following description of exemplary and non-limiting embodiments, which is given with reference to the drawings. [Brief explanation of the drawings]

[0041] [Figure 1] This is the first example of a wide-angle X-ray scattering profile of a film for electronic devices. [Figure 2] This is a second example of a wide-angle X-ray scattering profile of a film for electronic devices. [Figure 3] FIG. 1 is a schematic cross-sectional view showing the structure of a printed circuit board. DETAILED DESCRIPTION OF THE INVENTION

[0042] First Embodiment A first embodiment of a film for electronic devices according to the present invention will be described with reference to the drawings.

[0043] (Structure of the compound represented by formula (1)) The film for electronic devices according to this embodiment contains a compound represented by formula (1). [ka]

[0044] In formula (1), R 1 and R 2are independently selected from the group consisting of a hydrogen atom and a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, or together form an alkylidene group, and R 3 and R 4 are each independently selected from the group consisting of a hydrogen atom and a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, or together form an alkylidene group. Therefore, the compound represented by formula (1) is a homopolymer or copolymer having a polynorbornene skeleton. Note that terminal functional groups derived from the polymerization initiator are present at both ends of the polynorbornene skeleton, but are omitted in formula (1).

[0045] The compound represented by formula (1) is 1 , R 2 , R 3 , and R 4 and n are each a hydrogen atom. This monomer unit is an unsubstituted norbornene unit.

[0046] The compound represented by formula (1) is R 2 , R 3 , and R 4 are all hydrogen atoms, and R 1 is any one selected from the group consisting of an alkyl group, an alkenyl group, and a cycloalkyl group, and 3 and R 4 are all hydrogen atoms, and R 1 and R 2 and a monomer unit which together form an alkylidene group. These monomer units are, in other words, substituted norbornene units. The alkyl group, alkenyl group, cycloalkyl group, and alkylidene group preferably have 20 or less carbon atoms.

[0047] The alkyl group is not particularly limited and may be a methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, or an alkyl group with a longer chain length. However, the number of carbon atoms in the alkyl group is preferably 4 or more, more preferably 6 or more. The number of carbon atoms in the alkyl group is preferably 20 or less, more preferably 10 or less, and even more preferably 8 or less.

[0048] The alkenyl group is not particularly limited and may be an allyl group, a vinyl group, an ethynyl group, a propenyl group, a butenyl group, or an alkenyl group with a longer chain length. In an alkenyl group having 3 or more carbon atoms, the position and number of double bonds are not limited. However, the number of carbon atoms in the alkenyl group is preferably 2 or more, and more preferably 6 or more. The number of carbon atoms in the alkenyl group is preferably 20 or less, more preferably 10 or less, and even more preferably 8 or less.

[0049] The cycloalkyl group is not particularly limited and may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, or a cycloalkyl group having a larger number of carbon atoms. However, the number of carbon atoms in the cycloalkyl group is preferably 4 or more, more preferably 6 or more. The number of carbon atoms in the cycloalkyl group is preferably 20 or less, more preferably 10 or less, and even more preferably 8 or less.

[0050] The alkylidene group is not particularly limited and may be an ethylidene group, a propylidene group, a butylidene group, or an alkylidene group with a longer chain length. However, the number of carbon atoms in the alkylidene group is preferably 2 or more, and more preferably 6 or more. The number of carbon atoms in the alkylidene group is preferably 20 or less, more preferably 10 or less, and even more preferably 8 or less.

[0051] The compound represented by formula (1) can be, for example, a copolymer represented by the following formula (2). The copolymer represented by formula (2) contains two types of monomer units. The first monomer unit is the unsubstituted norbornene unit described above, and the second monomer unit is the substituted norbornene unit described above. The copolymer represented by formula (2) contains the first monomer unit and the second monomer unit in a molar ratio of n:m. [ka]

[0052] When the compound represented by formula (1) is a copolymer represented by formula (2), the ratio of the first monomer unit (unsubstituted norbornene unit) to the second monomer unit (substituted norbornene unit) is not particularly limited, and therefore the combination of n and m in formula (2) is arbitrary. The combination of n and m is preferably such that m / (n+m) is 0.05 or more (substituted norbornene unit is 5 mol% or more), more preferably 0.1 or more. Furthermore, the combination of n and m is preferably such that m / (n+m) is 0.99 or less, more preferably 0.8 or less, even more preferably 0.5 or less, and particularly preferably 0.3 or less.

[0053] (Physical properties of the compound represented by formula (1)) In the film for electronic devices according to this embodiment, the compound represented by formula (1) preferably has a glass transition temperature of 260°C or higher as measured by dynamic mechanical analysis (DMA) according to JIS K 7244:1998 under conditions of a heating rate of 5°C / min and a frequency of 1 Hz. When the compound represented by formula (1) has a glass transition temperature of 260°C or higher, it is easy to achieve the level of heat resistance required for electronic device applications. For example, when the film for electronic devices according to this embodiment is used on an electronic substrate, it is required to have heat resistance sufficient to withstand soldering performed on the substrate. The compound represented by formula (1) more preferably has a glass transition temperature of 300°C or higher.

[0054] In the electronic device film according to the present embodiment, the linear expansion coefficient of the compound represented by formula (1), as determined by thermal mechanical analysis (TMA) under the conditions of a tensile load of 10 mN, a temperature range of 25 to 250°C, and a heating rate of 5°C / min, is preferably 100 ppm or less. When the linear expansion coefficient of the compound represented by formula (1) is 100 ppm or less, the linear expansion coefficient of the electronic device film approaches that of copper foil, making the film suitable for use in applications where it is laminated with copper foil (e.g., as a substrate material or coating material for printed circuit boards). The linear expansion coefficient of the compound represented by formula (1) is more preferably 40 ppm or less. The lower limit of the linear expansion coefficient is not particularly limited, but may be 10 ppm or more. Thermomechanical analysis can be performed, for example, using a TMA7100 (manufactured by Hitachi High-Tech Science Corporation).

[0055] In the electronic device film according to this embodiment, the compound represented by formula (1) preferably has a dielectric constant of 3.0 or less, as measured at a frequency of 10 GHz according to JIS C 2565-1992. When the compound represented by formula (1) has a dielectric constant of 3.0 or less, high-frequency devices using the electronic device film according to this embodiment can transmit signals at high speed, making the film particularly suitable for use in electronic devices for high-speed communication. The compound represented by formula (1) more preferably has a dielectric constant of 2.5 or less.

[0056] In the electronic device film according to this embodiment, the compound represented by formula (1) preferably has a dielectric loss tangent of 0.003 or less, as measured at a frequency of 10 GHz according to JIS C 2565-1992. When the compound represented by formula (1) has a dielectric loss tangent of 0.003 or less, signal loss is suppressed in high-frequency devices using the electronic device film according to this embodiment, making it particularly suitable for use in electronic devices for high-speed communication. More preferably, the compound represented by formula (1) has a dielectric loss tangent of 0.002 or less.

[0057] [Other components constituting films for electronic devices] The film for electronic devices according to this embodiment may contain components other than the compound represented by formula (1). The content of each component is not particularly limited, but the content of the compound represented by formula (1) is preferably 40% or more by weight, more preferably 50% or more. The content of the compound represented by formula (1) is preferably 95% or less by weight, more preferably 90% or less.

[0058] The film for electronic devices according to the present embodiment preferably contains a filler having a relative dielectric constant of 10 or less. In this case, the content of the filler is preferably 50% or less by weight. Examples of such fillers include, but are not limited to, low-dielectric silica and alumina.

[0059] The film for electronic devices according to the present embodiment may contain known additives, such as, but not limited to, plasticizers, antioxidants, flame retardants, stabilizers, ultraviolet absorbers, antistatic agents, lubricants, water repellents, and oil repellents.

[0060] (Physical properties of films for electronic devices) For the electronic device film according to this embodiment, a wide-angle X-ray scattering (WAXS) profile was measured using a test device "BL03XU Beamline X-ray Scattering Measurement System" installed at SPring8 (Japan Synchrotron Radiation Research Institute, a public interest incorporated foundation). The detector was "Pilatus 1M," the camera distance was 0.3 m, the X-ray irradiation time was 5 seconds, and the number of accumulations was 1. X-rays with a wavelength of 0.1 nm were incident perpendicularly onto the film sample surface. Regarding the measured wide-angle X-ray scattering profile, the scattering vector q was 2 nm. -1 8nm or more -1 The first region below, and 10 nm -1 More than 20nm -1 The scattering pattern was evaluated in the range of the second region below. The scattering vector q is given by the following equation (3): where λ is the wavelength of the X-ray used in the measurement, and 2θ is the scattering angle.

number

[0061] The scattering vector q of the film for electronic devices according to this embodiment has at least one peak in the range of the first region. Preferably, the scattering vector q of the film for electronic devices according to this embodiment has at least one peak in each of the ranges of the first region and the second region. Preferably, the scattering vector q of the film for electronic devices according to this embodiment has at least two peaks in the range of the first region.

[0062] The peaks in the first region are derived from the crystalline portion of the compound represented by formula (1). Therefore, the positions, intensities, and number of peaks appearing in the first region vary depending on the crystalline structure of the compound represented by formula (1). Such a crystalline structure is determined by the substituent R 1 , R 2 , R 3 , and R 4 When the compound represented by formula (1) is a copolymer, the molar ratio of each monomer unit (for example, the ratio m / (n+m) in the copolymer represented by formula (2)) and the method for producing the compound represented by formula (1) can be influenced by such factors as the type of compound represented by formula (1), the molar ratio of each monomer unit when the compound represented by formula (1) is a copolymer (for example, the ratio m / (n+m) in the copolymer represented by formula (2)), and the method for producing the compound represented by formula

[0063] The peak in the second region is derived from the non-crystalline portion (amorphous component) of the compound represented by formula (1).

[0064] 1 and 2 are examples of wide-angle X-ray scattering profiles of the film for electronic devices according to this embodiment. Fig. 1 shows an example having two peaks in the first region, where the scattering vector q is near 3.5 and 7.0 (first region) and near 13.5 (second region). Fig. 2 shows an example having one peak in the first region, where the scattering vector q is near 7.0 (first region) and near 13.5 (second region).

[0065] The film for electronic devices according to this embodiment preferably has a linear expansion coefficient of 40 ppm or less, as determined by the slope of the temperature gradient from 50 to 100°C, in thermomechanical analysis under conditions of a tensile load of 10 mN, a temperature range of 25 to 250°C, and a heating rate of 5°C / min. When the linear expansion coefficient of the film for electronic devices is 30 ppm or less, the film can be suitably used in applications where it is laminated with copper foil (e.g., as a substrate material or coating material for printed circuit boards). The linear expansion coefficient of the film for electronic devices is more preferably 25 ppm or less. The lower limit of the linear expansion coefficient is not particularly limited, but can be, for example, 10 ppm or more. Thermomechanical analysis can be performed using, for example, a TMA7100 (manufactured by Hitachi High-Tech Science Corporation).

[0066] The film for electronic devices according to this embodiment preferably has a dielectric constant of 3.0 or less, measured at a frequency of 10 GHz according to JIS C 2565-1992. When the film for electronic devices has a dielectric constant of 3.0 or less, it is particularly suitable for use in electronic devices for high-speed communication. The film for electronic devices more preferably has a dielectric constant of 2.5 or less. The compound represented by formula (1) has a lower dielectric constant than substances conventionally used in this field, and therefore can easily achieve a dielectric constant suitable for use in a film for electronic devices.

[0067] The film for electronic devices according to this embodiment preferably has a dielectric loss tangent of 0.003 or less, measured at a frequency of 10 GHz according to JIS C 2565-1992. When the film for electronic devices has a dielectric loss tangent of 0.003 or less, it is particularly suitable for use in electronic devices for high-speed communication. The film for electronic devices more preferably has a dielectric loss tangent of 0.002 or less. The compound represented by formula (1) has a lower dielectric loss tangent than substances conventionally used in this field, and therefore can easily achieve a dielectric loss tangent suitable for use in a film for electronic devices.

[0068] The film for electronic devices according to this embodiment preferably has a Young's modulus of 0.5 GPa or more as measured according to JIS K 7127:1999. When the Young's modulus of the film for electronic devices is 0.5 GPa or more, the film for electronic devices has high flex resistance, making it particularly suitable for use in printed circuit boards. The Young's modulus of the film for electronic devices is more preferably 1.0 GPa or more. The upper limit of the Young's modulus of the film for electronic devices is not particularly limited, but may be, for example, 10 GPa or less.

[0069] The film for electronic devices according to this embodiment preferably has a breaking elongation of 3% or more as measured according to JIS K 7127:1999. When the breaking elongation of the film for electronic devices is 3% or more, the film for electronic devices has high flex resistance and is particularly suitable for use in printed circuit boards. The breaking elongation of the film for electronic devices is more preferably 5% or more. The upper limit of the breaking elongation of the film for electronic devices is not particularly limited, but may be, for example, 50% or less.

[0070] (Method for manufacturing films for electronic devices) As a method for producing the film for electronic devices according to this embodiment, a known film production method can be applied.

[0071] As a first example, the film for electronic devices according to this embodiment can be produced by cast molding. In this case, a mixed solution is prepared by mixing the compound represented by formula (1) and other materials (for example, a filler having a dielectric constant of 10 or less) in a solvent, and the mixed solution is applied to a substrate, followed by drying the coated surface, thereby obtaining the film for electronic devices according to this embodiment. Examples of solvents that can be used in this production method include toluene and decane.

[0072] The dielectric constant of the other material used here is determined by a known method for measuring the dielectric constant of the material. For example, when the other material is an electrically insulating ceramic material (silica, titania, zirconia, etc.), the dielectric constant of the material can be determined in accordance with JIS C 2141-1992.

[0073] As a second example, the film for electronic devices according to this embodiment can be produced by extrusion molding. In this case, the compound represented by formula (1) is molded into a film using a known extruder, thereby obtaining the film for electronic devices according to this embodiment. In this case, the compound represented by formula (1) needs to be heated to a temperature above its melting point, and the heating temperature can be, for example, 280 to 350°C. Note that materials such as fillers can be added to the compound represented by formula (1) in a molten state in the extruder.

[0074] (Applications of film for electronic devices) The film for electronic devices according to this embodiment can be used, for example, in a printed circuit board 1 including the film for electronic devices. Fig. 3 shows a schematic cross-sectional view illustrating the structure of the printed circuit board 1. The printed circuit board 1 has a substrate material 2, copper foil 3, and a covering material 4, and the substrate material 2 and the covering material 4 are made of the film for electronic devices according to this embodiment.

[0075] When manufacturing the printed circuit board 1, the substrate material 2 (film for electronic devices), copper foil 3, and covering material 4 (film for electronic devices) are stacked in this order and then hot-pressed, thereby thermally fusing the film for electronic devices (substrate material 2 and covering material 4) and the copper foil 3 together.

[0076] An adhesive layer may be interposed between the film for electronic devices (substrate material 2 and covering material 4) and the copper foil 3. Epoxy resin, polyimide resin, modified polyimide resin, etc. may be used as the adhesive layer. When an adhesive layer is provided, it is permissible to make the conditions of the process for bonding the film for electronic devices and the copper foil 3 milder, for example by lowering the heat press temperature.

[0077] Alternatively, only one of the substrate material 2 and the covering material 4 may be formed of the film for electronic devices according to this embodiment. In this case, the other of the substrate material 2 and the covering material 4 may be formed of a conventional material known as a material for printed circuit boards.

[0078] Second Embodiment Next, a second embodiment of the film for electronic devices according to the present invention will be described, with the same features as those of the first embodiment being simplified or omitted.

[0079] The film for electronic devices according to this embodiment contains a compound represented by formula (1), which is the same as the first embodiment. [ka]

[0080] In addition, the substituent R 1 , R 2 , R 3 , and R 4 The conditions relating to the above, the molar ratio of each monomer unit when the compound represented by formula (1) is a copolymer, and the preferred physical properties of the compound represented by formula (1) are the same as those in the first embodiment.

[0081] The film for electronic devices according to this embodiment contains a main material formed into a film shape and a compound represented by formula (1), and the compound is dispersed in the main material.

[0082] With this configuration, the film for electronic devices according to this embodiment exhibits not only the physical properties (mechanical properties, heat resistance, adhesiveness, insulating properties, etc.) attributable to the main material, but also improved electrical properties (dielectric constant and dielectric loss tangent lower than those of the main material) due to the addition of the compound represented by formula (1).The physical properties of the film for electronic devices according to this embodiment are the same as those of the first embodiment.

[0083] The compound represented by formula (1) can be dispersed in a main material as particles containing the compound represented by formula (1). In this case, the particle diameter of the particles can be, for example, 0.05 to 5 μm. Such particles can be produced, for example, by a melting method.

[0084] The film for electronic devices according to this embodiment preferably includes an adhesive layer having adhesiveness to metals, and an insulating layer at least partially covering the adhesive layer.

[0085] In one embodiment, the primary material may be a material that has adhesive properties to metal, such as an epoxy resin, polyimide, or modified polyimide. In this case, the layer containing the primary material functions as an adhesive layer. That is, in the adhesive layer, the compound represented by formula (1) is dispersed in the primary material.

[0086] In one embodiment, the main material may be an insulating material such as polyimide, modified polyimide, or liquid crystal polymer. In this case, the layer containing the main material functions as an insulating layer. That is, in the insulating layer, the compound represented by formula (1) is dispersed in the main material. Note that the insulating material is not particularly limited as long as it is a material that is commonly used as an electrical insulating material. For example, the insulating material may be a material having a volume resistivity of 1×10 measured by the method of JIS K6911-1995. 13 It can be a material with a resistance of Ω·m or more.

[0087] The method for forming the main material into a film is not particularly limited, and may be, for example, a casting method, a melt extrusion method, etc. However, it is preferable to disperse particles or a varnish containing the compound represented by formula (1) in the main material and then form the main material into a film.

[0088] The film for electronic devices according to this embodiment can be used, for example, in a printed circuit board including the film for electronic devices.

[0089] Other Embodiments Finally, other embodiments of the film for electronic devices according to the present invention will be described. Note that the configurations disclosed in the following embodiments can be applied in combination with the configurations disclosed in other embodiments, unless a contradiction occurs.

[0090] In the above embodiment, an example has been described in which the film for electronic devices according to the present embodiment is used for a printed circuit board 1. However, the use of the film for electronic devices according to the present invention is not limited to printed circuit boards, and it can also be used as peripheral components for electronic devices, such as a coverlay film or a bonding sheet.

[0091] Regarding other configurations, it should be understood that the embodiments disclosed in this specification are illustrative in all respects and that the scope of the present invention is not limited thereby. Those skilled in the art will easily understand that appropriate modifications are possible without departing from the spirit of the present invention. Therefore, other embodiments modified without departing from the spirit of the present invention are naturally included in the scope of the present invention. [Example]

[0092] The present invention will be further described below with reference to examples. However, the present invention is not limited to the following examples. , each reference example Items not specifically mentioned are the same as those in the above embodiment.

[0093] [ reference Example 1 Formula (1) In , R 1 is an n-hexyl group, and R 2 , R 3 , and R 4 are all hydrogen atoms from A film for electronic devices was prepared. The wide-angle X-ray scattering profile of the film for electronic devices had two peaks (q=3.9, 6.9) in the first region and one peak (q=13.6) in the second region.

[0094] [ reference Example 2 Formula (1) In , R 1 is an n-hexyl group, and R 2 is a hydrogen atom, and m / (n+m) is 0.2. from A film for electronic devices was prepared, and the wide-angle X-ray scattering profile of the film for electronic devices had one peak (q=7.0) in the first region and one peak (q=13.4) in the second region.

[0095] [Example 1 〕 Formula (1) In , R 1 is an n-hexyl group, and R 2 is a hydrogen atom, and m / (n+m) is 0.1. from A film for electronic devices was prepared, and the wide-angle X-ray scattering profile of the film for electronic devices had one peak (q=7.2) in the first region and one peak (q=13.4) in the second region.

[0096] [Example 2 〕 Formula (1) In , R 1 is an n-hexyl group, and R 2 is a hydrogen atom, and m / (n+m) is 0.05. from A film for electronic devices was prepared, and the wide-angle X-ray scattering profile of the film for electronic devices had one peak (q=7.4) in the first region and one peak (q=13.4) in the second region.

[0097] [ reference example 3 〕 Formula (1) In , R 1 is an n-butyl group, and R 2 is a hydrogen atom, and m / (n+m) is 0.2. fromA film for electronic devices was prepared, and the wide-angle X-ray scattering profile of the film for electronic devices had one peak (q=7.0) in the first region and one peak (q=13.5) in the second region.

[0098] [ Reference example 4 〕 In formula (1), R 1 is an n-butyl group, and R 2 A film for electronic devices was prepared from a copolymer represented by formula (2), in which n is a hydrogen atom and m / (n+m) is 0.05. The wide-angle X-ray scattering profile of the film for electronic devices had one peak (q=7.2) in the first region and one peak (q=13.5) in the second region.

[0099] [Example 3 〕 In formula (1), R 1 is a vinyl group, and R 2 A film for electronic devices was prepared from a copolymer represented by formula (2), in which n is a hydrogen atom and m / (n+m) is 0.1. The wide-angle X-ray scattering profile of the film for electronic devices had one peak (q=7.3) in the first region and one peak (q=13.4) in the second region.

[0100] [Example 4 〕 In formula (1), R 1 is a cyclohexyl group, and R 2 A film for electronic devices was prepared from a copolymer represented by formula (2), in which n is a hydrogen atom and m / (n+m) is 0.1. The wide-angle X-ray scattering profile of the film for electronic devices had one peak (q=7.2) in the first region and one peak (q=13.4) in the second region.

[0101] [Example 5 〕 In formula (1), R 1 and R 2A film for electronic devices was prepared from a copolymer represented by formula (2) in which m / (n+m) is 0.1 and m / (n+m) is a methyl group. The wide-angle X-ray scattering profile of the film for electronic devices has one peak (q=7.3) in the first region and one peak (q=13.4) in the second region.

[0102] [Evaluation of each Example and Reference Example] Example 1 5 , Reference example 1~ 4 The glass transition temperature, linear expansion coefficient, relative dielectric constant (10 GHz), and dielectric loss tangent (10 GHz) of each film for electronic devices were measured. The evaluation results are shown in Tables 1 and 2. All of the examples exhibited physical properties that could provide good heat resistance and electrical properties as films for electronic devices.

[0103] Table 1: Example 1 2, Reference examples 1~2 [Table 1]

[0104] Table 2: Example 3 5、 Reference example 3 、4 [Table 2] [Industrial Applicability]

[0105] The present invention can be used in electronic devices such as printed circuit boards. [Explanation of symbols]

[0106] 1: Printed circuit board 2: Substrate material 3: Copper foil 4: Covering material

Claims

1. a copolymer represented by formula (2) containing, as a main component, a compound having m / (n+m) of 0.05 or more and 0.1 or less in a weight ratio of 50% or more, In the wide-angle X-ray scattering profile, the scattering vector q is 2 nm －１ 8 nm or more －１ The following first region, and 10 nm －１ 20nm or more －１ A film for electronic devices having at least one peak in each of the following second regions: 【Chemistry 2】 In the copolymer, R ２ is a hydrogen atom, and R １ is a monomer unit selected from the group consisting of an unsubstituted n-hexyl group, a c-hexyl group, and a vinyl group; and R １ and R ２ and a monomer unit which combines to form an ethylidene group.

2. A film for electronic devices as described in claim 1, formed solely from the compound.

3. 3. The film for electronic devices according to claim 2, wherein the glass transition temperature measured by dynamic viscoelasticity measurement according to JIS K 7244:1998 under conditions of a temperature rise rate of 5°C / min and a frequency of 1 Hz is 299°C or higher.

4. 4. The film for electronic devices according to claim 2, wherein the linear expansion coefficient, specified as a slope from 50 to 100°C in thermomechanical analysis under conditions of a tensile load of 10 mN, a temperature range of 25 to 250°C, and a heating rate of 5°C / min, is 54 ppm or less.

5. 5. The film for electronic devices according to claim 2, wherein the relative dielectric constant measured at a frequency of 10 GHz in accordance with JIS C 2565-1992 is 3.0 or less.

6. 6. The film for electronic devices according to claim 2, wherein a dielectric loss tangent measured at a frequency of 10 GHz in accordance with JIS C 2565-1992 is 0.003 or less.

7. A copolymer represented by formula (2), containing 50% or more by weight of a compound having m / (n+m) of 0.05 or more and 0.1 or less as a main component, Further containing a filler having a relative dielectric constant of 10 or less, The content of the filler is 50% or less by weight, A film for electronic devices, wherein a wide-angle X-ray scattering profile has at least one peak in a first region where the scattering vector q is 2 nm −1 or more and 8 nm −1 or less, and at least one peak in a second region where the scattering vector q is 10 nm −1 or more and 20 nm −1 or less. 【Chemistry 2】 In the copolymer, a monomer unit in which R 2 is a hydrogen atom and R 1 is any one selected from the group consisting of an unsubstituted alkyl group, an alkenyl group, and a cycloalkyl group having 6 or less carbon atoms; and a monomer unit in which R 1 and R 2 together form an ethylidene group.

8. A film for electronic devices, comprising: a main material selected from an epoxy resin, a polyimide, a modified polyimide, and a liquid crystal polymer, formed into a film shape; and a compound dispersed in the main material, the compound being a copolymer represented by formula (2), wherein m / (n+m) is 0.05 or more and 0.1 or less. 【Chemistry 2】 During the ceremony, a monomer unit in which R 2 is a hydrogen atom and R 1 is any one selected from the group consisting of an unsubstituted alkyl group, an alkenyl group, and a cycloalkyl group having 6 or less carbon atoms; and a monomer unit in which R 1 and R 2 together form an ethylidene group.

9. having particles dispersed in the primary material; The film for electronic devices according to claim 8 , wherein the particles contain the compound.

10. An adhesive layer having adhesive properties to metal and an insulating layer at least partially covering the adhesive layer, the main material is a material having adhesiveness to metal selected from epoxy resin, polyimide, and modified polyimide; 10. The film for electronic devices according to claim 8, wherein the compound represented by formula (2) is dispersed in the main material in the adhesive layer.

11. An adhesive layer having adhesive properties to metal and an insulating layer at least partially covering the adhesive layer, the main material is an insulating material selected from polyimide, modified polyimide, and liquid crystal polymer; 10. The film for electronic devices according to claim 8, wherein the compound represented by formula (2) is dispersed in the main material in the insulating layer.

12. A printed circuit board comprising the film for electronic devices according to any one of claims 1 to 11.

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