Fluororesin sheet material and laminate containing the same

Abstract

Even when bonded at temperatures below the melting point of fluororesin, it exhibits excellent adhesion to the metal layer. We provide a fluororesin sheet material. [Solution] On at least one surface, at least one of the following (1) and (2) A fluororesin sheet material that satisfies the requirements. (1) The maximum peak height (Rp) when the surface condition is measured by atomic force microscopy is 30-1 50nm (2) The maximum peak depth (Rv) when the surface condition is measured by atomic force microscopy is -30~ -120nm

Description

[Technical Field]

[0001] This disclosure relates to a fluororesin sheet material and a laminate containing the same. [Background technology]

[0002] Used in antennas and transmission lines to realize high-speed communication using next-generation information and communication (high-frequency 5G). Printed circuit boards require low transmission loss characteristics. Given this background, printed circuit boards Fluoropolymer materials (PTFE, PFA, etc.) with excellent electrical properties are attracting attention as insulating materials for boards. It is being considered. On the other hand, fluororesin materials generally have poor adhesion to other materials, therefore, adhesion Surface modification techniques such as plasma treatment are used as improvements (Patent Document 1, etc.).

[0003] Patent Document 1 describes a method of surface-treating both the inorganic layer surface and the fluororesin layer surface, and the melting point of the fluororesin. In the above method for manufacturing a laminate by heat-pressing, the fluororesin layer is subjected to plasma treatment on the surface It is stated that the treatment should be carried out. Furthermore, each of the surface-treated inorganic layer and fluororesin layer The preferred range for the arithmetic mean roughness Ra is described.

[0004] Patent Document 2 describes a resin-coated metal foil having a resin layer on the surface of the metal foil, and a prepreg and contact The preferred ranges for the Ra of the resin layer to be attached and the ten-point average roughness (Rz) of the metal layer are described. ru.

[0005] Patent Document 3 describes a fluororesin film that has been subjected to surface treatment and annealing treatment, and fluororesin By setting the dimensional change rate and oxygen atom ratio of the film within a specific range, the fluororesin film Fluorine resin reduces defects during lamination between aluminum and copper foil, and also exhibits excellent adhesion to copper foil. It is stated that a lipid film can be obtained.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present disclosure aims to provide a fluororesin sheet-like material having excellent adhesion to a metal layer even when adhered at a temperature below the melting point of the fluororesin.

Means for Solving the Problems

[0008] The present disclosure is a fluororesin sheet-like material that satisfies at least one of the following (1) and (2) on at least one surface. (1) When the surface state is measured by an atomic force microscope, the maximum peak height (Rp) is 30 to 1 50 nm (2) When the surface state is measured by an atomic force microscope, the maximum valley depth (Rv) is -30 to -120 nm

[0009] It is preferable that the fluororesin sheet-like material satisfies both of the above (1) and (2). The fluororesin is preferably tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA ) or tetrafluoroethylene-hexafluoropropylene (FEP).

[0010] ​​​This disclosure relates to the following (3) and on the surface of at least one of the surfaces in contact with the metal layer. (4) A laminate comprising a fluororesin sheet material satisfying at least one of the above and a metal layer be. (3) The maximum peak height (Rp) when the surface condition is measured by atomic force microscopy is 30-15 0nm (4) When the surface condition is measured by atomic force microscopy, the maximum peak depth (Rv) is -30 to - 120nm

[0011] In the above laminate, the Rz of the surface of the metal layer that is in contact with the fluororesin sheet material is 1.5 It is preferable that the size is μm or less.

[0012] Furthermore, in the laminate described above, the fluororesin sheet material provides both (3) and (4) above. It is preferable that the above-mentioned metal layer is a fluororesin sheet. It is preferable that the Rz of the surface in contact with the T-shaped material is 1.5 μm or less.

[0013] In the above laminate, the measurement surface of the above fluororesin sheet material is measured using scanning X-ray photoelectron spectroscopy. The oxygen element ratio measured by optical analysis (XPS) is 1.35 atomic% or higher. It is preferable to do so.

[0014] In the above laminate, the measurement surface of the above fluororesin sheet material is measured using scanning X-ray photoelectron spectroscopy. The amount of functional groups (C=O) measured by optical analysis (XPS) must be 2.0% or more. preferable.

[0015] This disclosure relates to a laminate comprising a fluororesin sheet-like material and a metal layer, The surface of at least one of the surfaces in contact with the metal layer is less than (5) and (6) below At least one of the above conditions is met, and the above measurement surface of the fluororesin sheet material is measured using scanning X-ray light. The oxygen element ratio measured by electron spectroscopy (XPS) is 1.35 atomic% or less. It is also a layered structure. (5) In the state before lamination of the fluororesin sheet material, at least the surface in contact with the metal layer The maximum peak height (Rp) when the surface state on one side is measured by atomic force microscopy and , in the state before lamination of the metal foil, the metal on the surface in contact with the fluororesin sheet material. The ratio of the maximum peak height (Rp) when the foil surface is measured by atomic force microscopy to (Rp(fluorine) The resin sheet material / Rp (metal foil) content is 50-250%. (6) In the state before lamination of the fluororesin sheet material, at least the surface in contact with the metal layer The maximum peak depth (Rv) when the surface state on one side is measured by atomic force microscopy is The absolute value and the surface in contact with the fluororesin sheet material in the state before lamination of the metal foil. The ratio (Rv) of the maximum peak height (Rp) when the surface of a metal foil is measured using an atomic force microscope. The ratio of (fluororesin sheet material) to Rp (metal foil) is 50-200%.

[0016] The above laminate preferably satisfies both (5) and (6) above.

[0017] This disclosure relates to a laminate comprising a fluororesin sheet-like material and a metal layer, The surface of at least one of the surfaces in contact with the metal layer is less than (5) and (6) below At least one of the above conditions is met, and the same surface of the fluororesin sheet material is scanned with X-ray beam. The amount of functional groups (C=O) measured by electron spectroscopy (XPS) is 2.0% or more. It is also a laminated structure. (5) In the state before lamination of the fluororesin sheet material, at least the surface in contact with the metal layer The maximum peak height (Rp) when the surface state on one side is measured by atomic force microscopy and , in the state before lamination of the metal foil, the metal on the surface in contact with the fluororesin sheet material. The ratio of the maximum peak height (Rp) when the foil surface is measured by atomic force microscopy to (Rp(fluorine) The resin sheet material / Rp (metal foil) content is 50-250%. (6) In the state before lamination of the fluororesin sheet material, at least the surface in contact with the metal layer The maximum peak depth (Rv) when the surface state on one side is measured by atomic force microscopy is The absolute value and the surface in contact with the fluororesin sheet material in the state before lamination of the metal foil. The ratio (Rv) of the maximum peak height (Rp) when the surface of a metal foil is measured using an atomic force microscope. The ratio of (fluororesin sheet material) to Rp (metal foil) is 50-200%.

[0018] The above laminate preferably satisfies both (5) and (6) above.

[0019] In the above laminate, the fluororesin is tetrafluoroethylene-perfluoroalkyl Nyl ether (PFA) or tetrafluoroethylene-hexafluoropropylene (FE) P) is preferable. In the above laminate, the Rz of the surface of the metal layer in contact with the fluororesin sheet material is 1.5 μm The following is preferable:

[0020] In the above laminate, the adhesive strength between the measurement surface of the fluororesin sheet material and the metal layer is It is preferable that the concentration is 0.5 N / cm or higher. This disclosure also relates to a circuit board having the above-mentioned fluororesin sheet material or the above-mentioned laminate. . [Effects of the Invention]

[0021] The fluororesin sheet material disclosed herein can be bonded at a temperature below the melting point of the fluororesin. It exhibits excellent adhesion to metal layers. [Modes for carrying out the invention]

[0022] The details of this disclosure are described below. Conventionally, in surface modification of fluororesin sheets by plasma treatment, the requirements for obtaining good adhesion While patents specifying the amount of oxygen or specific functional groups are occasionally seen, they do not address bonding below the melting point. However, satisfactory adhesion cannot be obtained with those requirements alone. This can lead to peeling and a decrease in the reliability of the substrate in subsequent processes.

[0023] This disclosure relates to a method for surface-treating a fluororesin sheet material, which improves the in-plane uniformity of the surface treatment. By doing so, when bonding at a temperature below the melting point of the fluororesin, the bonding with metal layers such as copper foil is improved. This results in better adhesion. Conventionally, in order to improve adhesion, the Rz of the metal foil surface and the Ra of the fluororesin film surface were used. While evaluations have been made regarding Rz and other factors, the present inventors have developed a fluororesin sheet material surface Focusing on the maximum peak height (Rp) and maximum peak depth (Rv) of the surface, at least one of these can be identified. Even if bonding is performed at a temperature below the melting point of the fluororesin, if it is within this range, the bonding with the metal layer will not occur. It was revealed that it would be superior in quality. Furthermore, if the relationship between the metal foil Rp and the Rp or Rv of the fluorine sheet material is specific, adhesion It has good performance, maintains low transmission loss characteristics, and exhibits excellent properties when used as a circuit board. We found that a laminate having the following properties can be obtained.

[0024] (Fluororesin sheet material) The fluororesin sheet material of this disclosure has at least one surface state determined by atomic force microscopy. It is characterized by having a maximum peak height (Rp) of 30-150 nm when measured (1). It is.

[0025] The above maximum peak height (Rp) is 30-150 nm, which means that the contact point is below the melting point of the fluororesin. Under temperature conditions, functional groups present on the surface of the metal foil and the fluororesin sheet material form bonds. Because the distance is easily set to the appropriate level for formation, adhesion with the metal foil is good, and as a result, This eliminates cosmetic defects and peeling, improving the reliability of the circuit board. By enabling bonding at temperatures below the melting point of fluororesin, warping of the metal foil becomes less likely, and the outer The appearance improves. Furthermore, the reduced peeling resistance maintains surface smoothness, resulting in low transmission loss. The loss of properties is maintained. Furthermore, if the bonding temperature can be lowered, manufacturing becomes easier, and production Production efficiency will also increase.

[0026] Furthermore, the fluororesin sheet material of this disclosure has at least one surface state that can be examined using an atomic force microscope. The maximum peak depth (Rv) measured by this method is -30 to -120 nm (2). This serves as a distinguishing feature.

[0027] The above maximum peak depth (Rv) is -30 to -120 nm, and the maximum peak height (Rp) is -30 to -120 nm. At bonding temperatures below the melting point of the raw resin, the metal foil and the fluororesin sheet material are present on their surfaces. Because the functional groups tend to be at an appropriate distance for bonding, it exhibits good adhesion to metal foil. As a result, cosmetic defects and peeling are eliminated, improving the reliability of the circuit board. To rise. By enabling bonding at temperatures below the melting point of fluororesin, warping of the metal foil becomes less likely, and the outer The appearance improves. Furthermore, the reduced peeling resistance maintains surface smoothness, resulting in low transmission loss. The loss of properties is maintained. Furthermore, if the bonding temperature can be lowered, manufacturing becomes easier, and production Production efficiency will also increase.

[0028] Here, the maximum peak height (Rp) and maximum peak depth (Rv) are determined by the following method. ru. Using a scanning atomic force microscope AFM5000 (manufactured by Hitachi High-Tech Corporation), under the conditions shown below: Surface Rp and surface Rv of fluororesin sheet material surface and metal foil in a 10 μm square area We measured it. Cantilever: SI-DF20 (tip radius < 10 nm, spring constant 15 N / m) Measurement mode: AC mode Scanning frequency: 1Hz Pixel count: 256 x 256

[0029] The fluororesin sheet material of this disclosure has at least one surface state determined by atomic force microscopy. The maximum peak height (Rp) measured is 30-150 nm (1), and the maximum peak depth is (2) It is preferable that the Rv is -30 to -120 nm. Thus, by satisfying both conditions, the adhesive temperature below the melting point of the fluororesin can be used. In this context, the functional groups present on the surface of the metal foil and the fluororesin sheet material form a bond. This will create an even more appropriate distance.

[0030] The maximum peak height (Rp) is preferably 40-120 nm, and 50-100 nm. It is preferable that it be so. Furthermore, the maximum peak depth (Rv) is preferably -40 to -100 nm, and -50 to - A more preferable nm size is 90nm.

[0031] The fluororesin sheet material of this disclosure, which satisfies the above physical properties, is particularly capable of withstanding corona discharge. The surface is treated, and in this process, for example, nitrogen gas, argon and carbon dioxide gas are used as inert gases. By using this method and imparting functional groups with carbon dioxide, the in-plane uniformity of the surface treatment is enhanced. This is possible. Details of the surface treatment method will be described later.

[0032] (Fluororesin) The fluororesin contained in the fluororesin sheet material disclosed herein is any resin that contains fluorine. There are no particular limitations, and any known fluororesin can be used. In particular, tetrafluoroethylene (TFE)-(per)fluoro(alkylvinyl) Tetrafluoroethylene copolymer (PFA), or tetrafluoroethylene-hexafluoropropyl It is preferable that it be a (HFP) copolymer (FEP).

[0033] (Per)fluoro(alkyl vinyl ether) (PAVE) is a fluoroalkyl vinyl This disclosure may be an ether or a perfluoro(alkyl vinyl ether). In this context, "perfluoro(alkyl vinyl ether)" refers to an alkyl vinyl ether that does not contain CH bonds. It is lucyl vinyl ether. The PAVE that constitutes the above PAVE unit is given by the general formula (1): CF2 = CFO(CF2CFY 1 O) p -(CF2CF2CF2O) q -R f (1 ) (In the formula, Y 1 represents F or CF3, and R f This is a perfluoroalkyl group having 1 to 5 carbon atoms. represents. p represents an integer from 0 to 5, and q represents an integer from 0 to 5.) monomers, and , general formula (2): CFX=CXOCF2OR 1 (2) (where X is the same or different and represents H, F or CF3, and R 1 is linear or branched and contains at least 1 to 2 atoms selected from the group consisting of H, Cl, Br and I, and has 1 to 6 carbon atoms and may contain fluorine alkyl groups, or has 5 or 6 carbon atoms and may contain at least 1 to 2 atoms selected from the group consisting of H, Cl, Br and I and represents a cyclic fluoroalkyl group. At least one selected from the group consisting of monomers represented by the following can be mentioned. (where X is the same or different and represents H, F or CF3, and R is linear or branched

[0034] Among them, as the above PAVE, a monomer represented by the general formula (1) is preferable, and perfluoro (methyl vinyl ether), perfluoro(ethyl vinyl ether) and perfluoro (propyl vinyl ether) (PPVE), and at least one selected from the group consisting of is more preferable, and PPVE is even more preferable.

[0035] The content of the PAVE unit in the above TFE / PAVE copolymer is preferably 1.0 to 10% by mass, more preferably 2.0% by mass or more, still more preferably 3.5% by mass or more, particularly preferably 4.0% by mass or more, most preferably 5.0% by mass or more, more preferably 8.0% by mass or less, still more preferably 7.0% by mass or less, particularly preferably 6.5% by mass or less, most preferably 6.0% by mass or less. The amount of the above PAVE unit is measured by the F-NMR method 19 and The above TFE / PAVE copolymer consists only of TFE units and PAVE units. It may be a copolymer.

[0036] If the above fluororesin sheet material is made of a TFE / PAVE copolymer, the melting point The temperature is preferably 280-322°C, more preferably 290°C or higher, and even more preferably The temperature is below 315℃.

[0037] If the above fluororesin sheet material is made of a TFE / PAVE copolymer, The transition temperature (Tg) is preferably 70 to 110°C, and more preferably 80°C or higher. Yes, and more preferably 100°C or lower. The above glass transition temperature is determined by dynamic viscoelasticity measurement. It is a value obtained by measurement.

[0038] The above TFE / HFP copolymer contains TFE units and HFP units. The TFE unit content in the HFP copolymer is preferably 70% relative to the total monomer units. It is % by mass or more, more preferably 85% by mass or more, and preferably 99.8% by mass or more. It is less than or equal to 99% by mass, and even more preferably 98% by mass or less. ru.

[0039] The above TFE / HFP copolymer has a mass ratio of TFE units to HFP units (TFE / HFP). It is preferable that the ratio is 70-99 / 1-30 (mass%). ) is more preferably 85-95 / 5-15 (mass%).

[0040] The above TFE / HFP copolymer is further (per)fluoro(alkyl vinyl ether) (PAVE) units may be contained in the above TFE / HFP copolymer. As for VE units, the same ones as the PAVE units mentioned above can be cited. TFE / PAVE copolymer does not contain HFP units, therefore in that respect, TFE / HFP / This is different from PAVE copolymer.

[0041] The above TFE / HFP copolymer contains TFE units, HFP units, and PAVE units. In the case of a copolymer (hereinafter also referred to as "TFE / HFP / PAVE copolymer"), the mass ratio (TFE / HFP / PAVE) is 70-99.8 / 0.1-25 / 0.1-25 (mass %) ) is preferable. The above mass ratio (TFE / HFP / PAVE) is 75~98 / 1 It is more preferable that the ratio is 0.0~15 / 1.0~10 (mass%). The above TFE / HFP / PAVE copolymers have a total of 1 HFP unit and PAVE unit relative to the total monomer unit. It is preferable that it contains at least % by mass.

[0042] The above TFE / HFP / PAVE copolymer contains HFP units at 25% by mass or less of the total monomer units. It is preferable that the content of HFP units is more preferably 20% by mass or less. More preferably, it is 18% by mass or less, and particularly preferably 15% by mass or less. The HFP unit content is preferably 0.1% by mass or more, and more preferably 1% by mass or less. The content is above, and particularly preferably 2% by mass or more. The content of HFP units is: 19 F- It can be measured by NMR spectroscopy.

[0043] The PAVE unit content is more preferably 20% by mass or less, and even more preferably 10% by mass. It is less than or equal to mass%, and particularly preferably less than or equal to 3% by mass. Furthermore, the PAVE unit content is Preferably, it is 0.1% by mass or more, and more preferably 1% by mass or more. The amount of VE units is, 19 It can be measured by the 1F-NMR method.

[0044] The above TFE / PAVE copolymer and the above TFE / HFP copolymer are further processed with other ethylene It may contain ethylenically occurring monomer (α) units. Other ethylenically occurring monomer (α) units include: There are no particular limitations as long as the monomer unit is copolymerizable with TFE, HFP, and PAVE, for example For example, vinyl fluoride (VF), vinylidene fluoride (VdF), trifluoroethylene (Tr Fluorine-containing ethylenic monomers such as FE, chlorotrifluoroethylene (CTFE), and Examples include ethylene, propylene, and non-fluorinated ethylene monomers such as alkyl vinyl ethers. The content of other ethylenically active monomer (α) units is preferably 0 to 25% by mass. More preferably, it is 0.1 to 25% by mass.

[0045] The above copolymer is a TFE / HFP / PAVE / other ethylenically active monomer (α) copolymer. In this case, the mass ratio (TFE / HFP / PAVE / other ethylenic monomers (α)) is 70-9 Preferably, the ratio is 8 / 0.1~25 / 0.1~25 / 0.1~25 (mass%). TFE / HFP / PAVE / other ethylenically active monomer (α) copolymers are composed of units other than TFE units. It is preferable that the monomer units total 1% by mass or more.

[0046] The melting point of the above TFE / HFP copolymer is preferably 200 to 322°C, and more preferably The temperature is above 200°C, more preferably 220°C or higher, and more preferably 300°C. The following, and more preferably 280°C or lower.

[0047] The glass transition temperature (Tg) of the above TFE / HFP copolymer is preferably 60 to 110°C. Yes, more preferably 65°C or higher, and more preferably 100°C or lower. The transition temperature is a value obtained by measuring dynamic viscoelasticity.

[0048] The above-mentioned fluororesin, for example, contains monomers that form its constituent units and additives such as polymerization initiators. It can be manufactured by conventionally known methods such as emulsion polymerization or suspension polymerization after mixing. In particular, it is more preferable that it be obtained by emulsion polymerization.

[0049] The above fluororesin has a melt flow rate of 1 to 50 g / 10 min at 372°C and a load of 49 N. It is preferable to have one.

[0050] The above fluororesin is better if it has fewer functional groups, and especially if it has fewer unstable end groups. i. Such fluororesins can be produced by adjusting the conditions during manufacturing (polymerization reaction), The polymerized fluororesin is subjected to fluorine gas treatment, heat treatment, supercritical gas extraction, etc. There are methods to reduce the number of unstable end groups. Because some or all of it is converted to -CF3 and becomes a stable end group, fluorine gas treatment is preferred. It is so. When using fluororesin with a reduced number of unstable end groups in this way, the electrostatic loss tangent decreases. This is preferable in that it reduces the loss of electrical signals.

[0051] The number of unstable end groups mentioned above is not particularly limited, but for fluororesins with a main chain of 10 carbon atoms... 6 Preferably, the amount per unit is 450 or less, more preferably 250 or less, and 10 It is more preferably 0 or less, and most preferably 50 or less. Dielectric loss tangent reduction Considering the effects of [the relevant factor], a value of less than 10 is preferable, and 5 or less is even more preferable.

[0052] Unstable terminal groups include, specifically, -COF, -COOH free (free COOH), -COOH bonded (associated -COOH), hydroxyl group (-CH2OH, etc.), -CONH2, -COOR (R=CH3 etc.), -CF2H, -OCOO-R (normal Examples of functional groups include propyl carbonate, etc.

[0053] The number of unstable end groups is measured specifically by the following method. First, the above fluororesin is melted... Then, by compression molding, a film with a thickness of 0.25 to 0.3 mm is produced. The fluororesin was analyzed by Fourier transform infrared spectroscopy to obtain the infrared absorption spectrum of the above fluororesin. This yields a difference spectrum from the base spectrum, which is completely fluorinated and lacks functional groups. From the absorption peaks of specific functional groups appearing in this difference spectrum, according to the following formula (A), The carbon atoms in the above fluororesin are 1 × 10 6 Calculate the number of unstable terminals per unit. N = I × K / t (A) I: Absorbance K: Correction coefficient t: Film thickness (mm)

[0054] For reference, the absorption frequency, molar extinction coefficient, and complement of the unstable end groups in this specification are as follows: The positive coefficients are shown in Table 1. The molar extinction coefficients are based on FT-IR measurement data for small molecule model compounds. This was decided based on the following.

[0055] [Table 1]

[0056] The above fluorination treatment involves contacting an unfluorinated fluororesin with a fluorine-containing compound. It can be done by having someone do it.

[0057] The above fluorine-containing compound is not particularly limited, but under fluorination treatment conditions, fluorine radio Examples of fluorine radical sources that generate fluorine radicals include F2 gas. S, CoF3, AgF2, UF6, OF2, N2F2, CF3OF, halogen fluoride (examples) Examples include IF5 and ClF3.

[0058] The fluorine radical source such as F2 gas mentioned above may be at 100% concentration, but the active gas It is preferable to mix it with and dilute it to 5-50% by mass before use, and to dilute it to 15-30% by mass. It is more preferable to use it as follows. The above inert gases include nitrogen gas, helium gas, and While gases such as argon can be used, nitrogen gas is preferred from an economic standpoint.

[0059] The conditions for the above fluorination treatment are not particularly limited, and include molten fluororesin and fluorine-containing The compound may be brought into contact with the fluororesin, but usually the temperature should be below the melting point of the fluororesin, preferably 20-220°C. The fluorination treatment can be carried out at a temperature of °C, more preferably 100 to 200 °C. The fluorination treatment is generally carried out for 1 to 30 hours, preferably 5 to 25 hours. It is preferable to bring an untreated fluororesin into contact with fluorine gas (F2 gas).

[0060] In this specification, the content of each monomer unit constituting the fluororesin is expressed by NMR, FT-IR It can be calculated by appropriately combining elemental analysis and X-ray fluorescence analysis depending on the type of monomer.

[0061] The fluororesin sheet material of this disclosure may contain components other than fluororesin. The components that can be contained are not particularly limited, but include silica particles, glass short fibers, etc. Examples include fillers, fluorine-free thermosetting resins, thermoplastic resins, etc. The content of components other than fluororesin is not particularly limited, but it should be 10% by mass or less. It is more preferable that the amount is 5% by mass or less, and even more preferable that it is 5% by mass or less.

[0062] At least one surface of the fluororesin sheet material of this disclosure is analyzed using a scanning X-ray photoelectron spectroscopy system. The oxygen element ratio measured by XPS must be 1.35 atomic% or higher. It is preferable. Furthermore, the oxygen element ratio is more preferably 1.5 atomic% or higher, and 1.8a It is even more preferable that it be above 2.0 atomic%, and more preferably above 2.0 atomic%. That is also preferable. Furthermore, the upper limit of the above oxygen element ratio is not particularly limited, but is 25 atomic% or less. It is preferable that it be below, more preferably 20 atomic% or less, and 15 at It is even more preferable that the omic% is less than or equal to 0%. If the oxygen element ratio is within the above range, it is advantageous in that the amount of functional groups contributing to adhesion is suitable. That is the case.

[0063] Here, the oxygen element ratio is determined by the following method. (Method for measuring the oxygen element ratio) Scanning X-ray Photoelectron Spectroscopy (XPS / ESCA) PHI5000VersaProb Using eII (manufactured by ULVAC-PHI, Inc.), under the conditions shown below, a fluororesin sheet was used. The oxygen element ratio on the surface of the T-shaped material was measured. Carbon, oxygen, fluorine, nitrogen, and silicon were tested. The oxygen element ratio was determined from the composition ratio of C1s, O1s, F1s, N1s, and Si2p. Radiation source: Monochromatized AlKα Beam diameter: 100 μm X-ray output: 25W Measurement area: 1000μm x 300μm Pass energy: 23.5 eV Detection angle: 45°

[0064] Furthermore, scanning X-ray photoelectron spectroscopy is performed on at least one surface of the fluororesin sheet material of this disclosure. The amount of functional groups (C=O) measured by the analytical instrument (XPS) must be 2.0% or more. preferable. Furthermore, the amount of functional groups (C=O) is more preferably 3% or more. It is more preferable that the amount be 4% or more, and most preferable that it be 5% or more. Furthermore, the upper limit of the amount of the above functional group (C=O) is not specifically limited, but is 35% or less. It is preferable that it be 30% or less, more preferably 20% or less. preferable. If the amount of functional groups (C=O) is within the above range, the amount of functional groups that contribute to adhesion will be suitable. It has advantages in that it improves adhesion and durability.

[0065] Here, the amount of functional group (C=O) is determined by the following method. (Method for measuring the amount of functional groups (C=O)) The C1s narrow spectrum obtained from XPS is processed using MultiPak software (Al The signal was separated into five peaks under the conditions shown below using a back-fi device, and the result was obtained from their ratio. The full width at half maximum (FMAX) of peaks 1 to 4 was standardized to 1.83, and the FMAX of peak 5 was the original spectrum. It was designed to match the shape of the tub.

[0066] [Table 2]

[0067] The fluororesin sheet material of this disclosure preferably has a thickness of 1 to 100 μm. The upper limit is more preferably 50 μm or less, and even more preferably 30 μm or less. The lower limit mentioned above is more preferably 3 μm or larger, and more preferably 5 μm or larger. It is preferable.

[0068] The thickness of the above fluororesin sheet material was measured using the film thickness measurement system F20 (Filmetr These values ​​were measured using a reflectance spectrometer (manufactured by ICS Corporation).

[0069] The Ra (arithmetic mean roughness) of the fluororesin sheet material of this disclosure in a 10 μm square is 20n It is preferably less than or equal to m, more preferably less than or equal to 15 nm, and less than or equal to 10 nm. It is even more preferable that it be present. The lower limit is not particularly limited, but is 5 nm or greater. It is preferable. If the above Ra is within the above range, the smoothness of the raw material itself is high, and the surface treatment is applied more uniformly within the plane. It is desirable in that respect.

[0070] Furthermore, the surface state of the fluororesin sheet material of this disclosure is analyzed using a scanning X-ray photoelectron spectroscopy system. The oxygen element ratio measured by XPS / ESCA and the fluororesin sheet. The material was subjected to an argon gas cluster ion beam at an incidence angle of 45° for 15 minutes in the depth direction. After interetching, measurements were taken using a scanning X-ray photoelectron spectroscopy (XPS / ESCA) analyzer. It is preferable that the difference in the oxygen element ratio when determined is 1.0 atomic% or more. The greater the difference in the oxygen element ratio from the surface to the depth, the more the adhesion is maintained while achieving a predetermined result. This is preferable because it allows for the elimination of transmission loss.

[0071] The oxygen element ratio after etching as described above is, in the fluororesin sheet material, surface treatment This represents the oxygen element ratio on the surface before the process. Therefore, the difference in the above oxygen element ratio is the surface This represents the increased oxygen element ratio resulting from the treatment.

[0072] The above fluororesin sheet material may be on one side only or both sides, within the same plane of the sheet material It is preferable that the adhesive strength when the two materials are bonded together at 200°C is greater than 30 N / m. By having such adhesive strength, after heat treatment of the fluororesin sheet material However, it has excellent adhesion when used in combination with various other substrates, The adhesive strength is preferably greater than 50 N / m, and more preferably greater than 100 N / m. That is even more preferable.

[0073] The above adhesive strength is more specifically determined by overlapping the surface-treated surfaces of two fluororesin sheet materials. Samples prepared using a press (200℃, 0.1MPa, 60s) were cut into 10mm wide strips. Cut into shape, and use the precision universal testing machine Autograph AGS-X 100N (Shimadzu Corporation) Using (manufactured), the unattached parts of the strip-shaped sample are attached to the top and bottom chucks of the autograph. The peel strength was measured by gripping it and pulling it at a speed of 100 mm per minute, and the obtained The value was defined as the adhesive strength.

[0074] The resin sheet material of this disclosure has a dielectric loss tangent of less than 0.0015 at 10 GHz. This is preferable. By keeping it within this range, the loss of electrical signals in the circuit can be kept low. This is preferable in that it allows for the above. The dielectric loss tangent is more preferably less than 0.0013. It is more preferable that it be less than 0.0010, and most preferably 0.00050 or less. Furthermore, assuming that signals will be transmitted at higher frequencies and antennas will be transmitted and received, 40 The dielectric loss tangent at GHz is preferably less than 0.0015, and preferably less than 0.0013. It is more preferable that it is less than 0.0010, and even more preferable that it is less than 0.0005. A value of 0 or less is most preferable. To keep the dielectric loss tangent within the above range, use a resin with fewer unstable end groups. It is preferable to use a fluororesin that has undergone terminal fluorination treatment, and it is even more preferable to use a fluororesin that has undergone terminal fluorination treatment.

[0075] (Method for manufacturing fluororesin sheet material) The following details an example of a method for manufacturing the fluororesin sheet material described above. The disclosed fluororesin sheet material is not limited to those manufactured by the following manufacturing methods. stomach. The fluororesin sheet material of this disclosure does not particularly limit the molding method for forming it into a sheet. However, for example, methods using melt molding such as extrusion molding, solutions containing fluororesin or Methods include a casting method in which a dispersion is prepared, applied to a substrate, and dried. Furthermore, the sheet was stretched using either uniaxial or biaxial stretching. It may be a sheet, or it may be an unstretched sheet. Furthermore, the fluororesin sheet material may be partially It may also be a laminated structure including a fluororesin layer.

[0076] The fluororesin sheet material obtained by this method is subjected to appropriate conditions on one side or By performing surface treatment on both sides, the above-mentioned maximum peak height (Rp) and maximum peak depth (R It can be a fluororesin sheet material having (v)

[0077] The specific methods for surface modification described above are not limited, but some specific examples are given below. I will elaborate. Surface modification of fluororesin sheet materials is performed using conventional methods such as corona discharge treatment and glow discharge. Discharge treatments such as plasma discharge treatment and sputtering treatment can be employed. In particular, Corona discharge treatment is preferred. For example, oxygen gas, nitrogen gas, hydrogen gas, carbon dioxide, methane gas, ethylene gas in a discharge atmosphere In addition to being able to control the surface free energy by introducing gases such as ion gas, organic compounds can be used. The surface to be modified is exposed to an atmosphere of an inert gas containing organic compounds, which is an inert gas, and the electrodes By applying a high-frequency voltage between them, a discharge is induced, which generates active species on the surface. Next, by introducing functional groups of organic compounds or by graft polymerization of polymerizable organic compounds... This allows for surface modification. Examples of the above inert gases include nitrogen gas and helium. Examples include mugas and argon gas.

[0078] In particular, it is preferable to use nitrogen gas and argon gas in combination. Furthermore, it is preferable to use carbon dioxide. This is preferable. The preferred ratio (by volume) of nitrogen gas to argon gas is 90 / 10 to 40 / 60. Furthermore, a ratio of 80 / 20 to 50 / 50 is even more preferable. It is not certain, but by adjusting the Ar ratio to a suitable range, the discharge becomes more stable and the surface modification becomes more uniform. It is thought that this is possible. Furthermore, the amount of carbon dioxide is preferably 0.05 to 5% by volume relative to nitrogen gas / argon gas. Ideally, the volume should be between 0.1 and 2 percent. It is not certain, but by mixing in an appropriate amount of carbon dioxide, the contact on the surface of the fluororesin sheet material The functional groups that contribute to adhesion are considered to be within a suitable range.

[0079] The organic compound in the inert gas containing the aforementioned organic compound is polymerizable or non-polymerizable, containing an oxygen atom. Examples include polymerizable organic compounds, such as vinyl esters like vinyl acetate and vinyl formate. ;Acrylates such as glycidyl methacrylate;Vinyl ethyl ether, vinyl ethers such as methyl ether and glycidyl methyl ether; acetic acid and formic acid. Acids; such as methyl alcohol, ethyl alcohol, phenol, ethylene glycol, etc. Alcohols; ketones such as acetone and methyl ethyl ketone; ethyl acetate and ethyl formate. Carboxylic acid esters such as acrylic acid; acrylic acids such as acrylic acid and methacrylic acid. Among these, the modified surface is less prone to deactivation, meaning it has a longer lifespan and is easier to handle. For these reasons, vinyl esters, acrylic acid esters, and ketones are preferred, and vinyl acetate in particular. Nyl, glycidyl methacrylate is preferred.

[0080] The concentration of the organic compound in the aforementioned inert gas containing the organic compound depends on its type and the surface modification of the fluorine. Although it varies depending on the type of resin, it is usually 0.1 to 3.0% by volume, preferably 0.1 to 1%. 0.0% by volume, more preferably 0.15 to 1.0% by volume, even more preferably 0.30 to 1.0% by volume This is a percentage of the capacity. The discharge conditions depend on the desired degree of surface modification, the type of fluororesin, and the type and concentration of organic compounds. The appropriate selection should be made depending on the circumstances. Typically, the discharge rate is 50-1500 W·min / m 2 , preferred Or 70W·min / m 2 More than 1400W min / m 2Discharge treatment will be performed within the following range. The processing temperature can be any temperature within the range of 0°C to 100°C. Fluororesin Due to concerns about stretching and wrinkling of the sheet-like material, a temperature of 80°C or lower is preferable. The degree of surface modification of fluororesin sheet materials depends on the heat applied during lamination with metal foil, etc. Considering that the oxygen elements on the surface are deactivated by various factors, reducing the adhesive strength, ESCA The observed oxygen element abundance is 1.5% or higher, and 1.75% or higher is preferable. It is preferable that it be 2.0% or more, and even more preferable that it be 2.5% or more. i. There are no specific regulations regarding the upper limit, but considering the impact on productivity and other physical properties, 2 It is preferable that the amount be 5.0% or less. While there are no specific requirements regarding the relative abundance of nitrogen, it is preferable that it be 0.1% or higher.

[0081] In the above surface modification process, the discharge rate, which indicates the output per unit area, should be 1.0 to 10 W / cm². 2 Discharge treatment is performed within the range, and the gas concentration / line velocity ratio at that time is 0.005~0.05 L / It is preferable to adjust it to the range of m. The gas concentration / line velocity ratio referred to here is the organic compound in the inert gas containing the organic compound This represents the ratio obtained by dividing the concentration of a substance by the line speed. If the flow rate is lower than 0.005 L / m, the space will not be sufficiently filled with gas relative to the transport speed, and the activity will not be activated. The transformed gas becomes less likely to come into contact with the surface of the fluororesin sheet material, resulting in a decrease in uniformity within the surface. This is a tendency. If the concentration is higher than 0.05 L / m, the surface is over-treated and damaged. Furthermore, the formation of low molecular weight compounds on the surface creates a brittle layer, which actually lowers the adhesive strength. This tends to lead to the following. Therefore, the surface of the fluororesin sheet material is treated more uniformly, Since it is presumed that the required level of adhesion can be achieved, processing within this range is particularly preferable.

[0082] Furthermore, in the above method, the surface state of one or both sides of the fluororesin sheet material is scanned. The oxygen element ratio measured by a Type X-ray photoelectron spectroscopy (XPS / ESCA) analyzer, The fluororesin-containing layer is subjected to an incident angle of 45° by an argon gas cluster ion beam. After etching in the depth direction for 15 minutes, scanning X-ray photoelectron spectroscopy (XPS / ES) is performed. The difference in the oxygen element ratio measured by CA is 1.0 atomic% or more. Surface treatment is preferable.

[0083] In the above method, when surface treatment is performed with a gas containing an organic compound, the resin surface By creating localized irregularities, the coefficient of dynamic friction between the metal foil surface and the fluororesin sheet-like material surface can be improved. It is also preferable that the value can be set to 0.4 or less. In other words, good adhesive strength is achieved. In addition, the coefficient of dynamic friction can be made small. This makes it possible to create long laminates. This is preferable because it prevents winding defects.

[0084] The fluororesin sheet material surface-treated using the above method is subjected to annealing treatment, and the remaining The retaining stress may be removed. This allows for lamination with metal foil to produce a laminate. In the process, the dimensional change of the fluororesin sheet material due to heat from the pressure roll is reduced, and wrinkles are eliminated. Because the laminates can be bonded together without any impurities, defects in the appearance of the laminate can be suppressed. Heat treatment reduces the amount of oxygen on the surface of the fluororesin sheet material. Therefore, sufficient surface oxygen is required at the time the fluororesin sheet material and the metal foil are bonded together. It is preferable to perform surface modification under conditions that allow for obtaining a sufficient quantity.

[0085] Annealing can be performed by heat treatment. This heat treatment can be performed, for example, by rolling to This can be done by passing the material through a heating furnace using a roll system. It can then be placed in a batch-type drying oven. Heat treatment may be performed.

[0086] The annealing temperature should preferably be above the glass transition temperature of the fluororesin (-20°C) and below its melting point. More preferably, the temperature is above the glass transition temperature of the fluororesin and below the melting point of -20°C. It is even more preferable that the fluororesin has a glass transition temperature above its melting point and a melting point below -60°C. The processing time is not particularly limited, but can be adjusted as needed, for example, between 0.5 and 60 minutes.

[0087] When heating using the roll-to-roll method described above, the tension depends on the thickness of the fluororesin sheet material and the setting This can be adjusted as needed by maintaining a constant temperature, but it is preferable to keep it below 20 N / m. By heating under such conditions, internal stresses can be sufficiently relieved, and dimensional changes and other phenomena can be avoided. It is preferable in that it does not cause any problems.

[0088] The above surface treatment and annealing treatments are not limited to any particular order, and each The number of times the process is performed is not limited to just once; it may be performed two or more times.

[0089] (Laminated structure) The fluororesin sheet material disclosed herein is suitable for forming laminates with metals, resin substrates, etc. It will be used. This disclosure describes how the surface state of at least one of the surfaces in contact with the metal layer can be determined by atomic force microscopy. (3) Fluororesin sheet-like material with a maximum peak height (Rp) of 30-150 nm when measured. It is also a laminate containing a material and a metal layer. Furthermore, this disclosure describes how to determine the surface state of at least one of the surfaces in contact with the metal layer using an atomic force microscope. The maximum mountain depth (Rv) measured by (4) fluorine tree It is also a laminate containing a grease-like sheet material and a metal layer.

[0090] In the case of the laminate described above, the surface of the metal foil and fluororesin sheet material in the micro-region The existing functional groups are more likely to be at an appropriate distance for bond formation, improving adhesion and durability. It is excellent in that respect.

[0091] The laminate of the present disclosure is in contact with the surface of the fluororesin sheet material having the above-mentioned properties and the metal layer. It is preferable that the configuration be such that Furthermore, if the fluororesin sheet material is a laminate in which one surface is in contact with a metal layer, The surface condition should satisfy the above characteristics. Also, both sides of the fluororesin sheet material In the case of a laminate in contact with a metal layer, the surface condition of at least one of the surfaces satisfies the above characteristics. Any material will do, and it is especially preferable that the surface conditions of both sides satisfy the above characteristics. stomach.

[0092] Furthermore, the surface state of at least one of the surfaces in contact with the metal layer is measured using an atomic force microscope. The maximum peak height (Rp) when set is 30-150 nm (3), and the maximum peak depth (R (4) A fluororesin sheet material having a density of -30 to -120 nm, and a metal layer. It is preferable that the structure be in layers.

[0093] (metal layer) In this disclosure, examples of metal species constituting the metal layer include copper, aluminum, and stainless steel. Examples include nickel and gold. These alloys can be used. Conductive From the viewpoint of circuit processability, it is preferable to use copper foil.

[0094] The metal foil forming the above metal layer has a surface Rz1. It is preferable that the thickness is 5 μm or less. That is, the fluororesin sheet material of this disclosure has a thickness of Rz It also exhibits excellent adhesion to highly smooth metal foils with a thickness of 1.5 μm or less. The above metal foil is If, at least the surface in contact with the aforementioned fluororesin sheet material has a thickness of Rz of 1.5 μm or less Often, the other aspect does not specifically limit the Rz value.

[0095] The above Rz represents the highest point (maximum mountain height: Rp) and the deepest point (maximum valley depth: This is the sum of Rv). The above surface roughness is the ten-point average roughness specified in JIS-B0601. Yes. In this specification, Rz is defined as a surface roughness meter (product name: Sa) with a measurement length of 4 mm. These values ​​were measured using a 470A (manufactured by Tokyo Seiki Co., Ltd.).

[0096] The copper foil described above is not particularly limited in thickness, but is preferably in the range of 1 to 100 μm. It is more preferable that the particle size be in the range of 5 to 50 μm, and even more preferable that it be in the range of 9 to 35 μm.

[0097] The above copper foil is not particularly limited; specifically, it could be rolled copper foil, electrolytic copper foil, etc. It can be listed.

[0098] The copper foil with a thickness of Rz 1.5 μm or less is not particularly limited and commercially available foils can be used. Examples of commercially available copper foils with an Rz of 1.5 μm or less include electrolytic copper foil CF-T9DA-SV- Examples include 18 (thickness 18μm / Rz 0.85μm) (manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.). It is possible.

[0099] The above copper foil is surface-treated to enhance its adhesive strength with the fluororesin sheet material of this disclosure. It may be something that has been applied.

[0100] The above surface treatments are not particularly limited, but include silane coupling treatment, plasma treatment, and corona treatment. These include sterilization, UV treatment, and electron beam treatment, and the reactive functional groups of silane coupling agents are, While not particularly limited, from the viewpoint of adhesion to fluororesin sheet-like materials, amino groups, ( At least one selected from meth)acrylic groups, mercapto groups, and epoxy groups is used at the end. It is preferable that it has. Furthermore, the hydrolyzable group is not particularly limited, but methoxy Examples include alkoxy groups such as ethoxy groups. The copper foil used in this disclosure is a rust-preventive layer It may also have an oxide film (such as chromate), a heat-resistant layer, etc. formed on it.

[0101] A surface-treated copper foil having a surface treatment layer of the above-mentioned silane compound on the surface of the copper foil is a surface-treated copper foil having the above-mentioned silane compound After preparing a solution containing [the specified substance], the copper foil is surface-treated using this solution to manufacture it. It is possible.

[0102] The copper foil described above has been roughened on its surface to improve adhesion with fluororesin sheet material, among other things. It may also have a processing layer. Furthermore, if the roughening process may degrade the performance required in this disclosure, Accordingly, the amount of roughening particles electrodeposited onto the copper foil surface is reduced, or the roughening treatment is omitted altogether. It is also possible to do so.

[0103] Between the copper foil and the surface treatment layer, a heat-resistant treatment layer (nickel-metallic) is placed to improve various properties. One selected from the group consisting of a rust-preventive treatment layer and a chromate treatment layer (e.g., titanium plating), etc. More than one layer may be provided. These layers may be a single layer or multiple layers.

[0104] In the laminate of this disclosure, the maximum peak height (Rp) measured by the atomic force microscope is ) and / or the surface of a plane with a maximum peak depth (Rv) of -30 to -120 nm is scanned with X-ray beam. The oxygen element ratio measured by electron spectroscopy (XPS) is 1.35 atomic% or less. It is preferable to use a fluororesin sheet material as described above. Furthermore, in the laminate of this disclosure, the maximum peak height measured by the atomic force microscope is Scanning the surface of a plane where (Rp) and / or maximum peak depth (Rv) are -30 to -120 nm The amount of functional groups (C=O) measured by X-ray photoelectron spectroscopy (XPS) was 2.0ato. It is preferable to use a fluororesin sheet material with a mic% or higher content.

[0105] Furthermore, this disclosure relates to a laminate comprising a fluororesin sheet-like material and a metal layer, wherein the fluororesin In the state before lamination of the sheet-like material, at least one surface of the surface in contact with the metal foil The maximum peak height (Rp) measured by atomic force microscopy of the surface state and the state before lamination of the metal foil. In this state, the surface of the metal foil in contact with the fluororesin sheet material is subjected to interatomic forces. Ratio of maximum peak height (Rp) measured by microscope (Rp(fluororesin sheet material) ) / Rp(metal foil)) is 50-250% (5), and the above fluororesin sheet material Oxygen element ratio measured on the same surface using scanning X-ray photoelectron spectroscopy (XPS). It is also a laminate with a concentration of 1.35 atomic% or more.

[0106] This disclosure relates to a laminate comprising a fluororesin sheet-like material and a metal layer, wherein the fluororesin sheet In the state before lamination of the material, the surface of at least one surface that is in contact with the metal layer The absolute value of the maximum peak depth (Rv) measured by atomic force microscopy, and the lamination of the metal foil. In the previous state, the surface of the metal foil in contact with the fluororesin sheet material is interatomic The ratio (Rv) of the maximum peak height (Rp) measured by force microscopy (fluororesin sheet material) The material (Rp) / (metal foil) is 50-200% (6), and the above fluororesin sheet material The oxygen element ratio of the same surface was measured by scanning X-ray photoelectron spectroscopy (XPS). It is also a laminate with a concentration of 1.35 atomic% or higher.

[0107] Furthermore, this disclosure relates to a laminate comprising a fluororesin sheet-like material and a metal layer, wherein the fluororesin In the state before lamination of the sheet-like material, at least one surface of the surface in contact with the metal layer The maximum peak height (Rp) measured by atomic force microscopy of the surface state and the state before lamination of the metal foil. In this state, the surface of the metal foil in contact with the fluororesin sheet material is subjected to interatomic forces. Ratio of maximum peak height (Rp) measured by microscope (Rp(fluororesin sheet material) ) / Rp(metal foil)) is 50-250% (5), and, When the surface condition of the same surface of the above-mentioned fluororesin sheet material was measured using an atomic force microscope, The absolute value of the maximum peak depth (Rv) and the metal foil on the surface in contact with the fluororesin sheet material. The ratio of the maximum peak height (Rp) measured on the surface by atomic force microscopy to (Rv(fluorine tree) The oily sheet material / Rp (metal foil) is 50-200% (6), and the above fluororesin The surface of the same side of a sheet-like material was measured using a scanning X-ray photoelectron spectroscopy (XPS) analyzer. It is preferable that the laminate has an oxygen element ratio of 1.35 atomic% or more.

[0108] This disclosure relates to a laminate comprising a fluororesin sheet-like material and a metal layer, wherein the fluororesin sheet In the state before lamination of the material, the surface of at least one surface that is in contact with the metal layer The maximum peak height (Rp) measured by atomic force microscopy, and the state of the metal foil before lamination. In this case, the surface of the metal foil in contact with the above-mentioned fluororesin sheet material is examined using an atomic force microscope. The ratio of the maximum peak height (Rp) measured by (Rp (fluororesin sheet material) / R p(metal foil) is 50-250% (5), and the same surface of the above fluororesin sheet material The amount of functional groups (C=O) on the surface was measured using scanning X-ray photoelectron spectroscopy (XPS). It is also a laminate in which the content is 2.0% or more.

[0109] This disclosure relates to a laminate comprising a fluororesin sheet-like material and a metal layer, wherein the fluororesin sheet In the state before lamination of the material, the surface of at least one surface that is in contact with the metal layer The absolute value of the maximum peak depth (Rv) measured by atomic force microscopy, and the lamination of the metal foil. In the previous state, the surface of the metal foil in contact with the fluororesin sheet material is interatomic The ratio (Rv) of the maximum peak height (Rp) measured by force microscopy (fluororesin sheet material) The material (Rp) / (metal foil) is 50-200% (6), and the above fluororesin sheet material Functional groups (C) were measured on the same surface using scanning X-ray photoelectron spectroscopy (XPS). It is also a laminate in which the amount of =O is 2.0% or more.

[0110] Furthermore, this disclosure relates to a laminate comprising a fluororesin sheet-like material and a metal layer, wherein the fluororesin In the state before lamination of the sheet-like material, on at least one of the surfaces in contact with the metal layer The maximum peak height (Rp) when the surface state is measured by an atomic force microscope, and before lamination of the metal foil In the state of, the ratio (Rp (fluororesin sheet-like material ) / Rp (metal foil)) of the maximum peak height (Rp) when the surface of the metal foil in contact with the fluororesin sheet-like material is measured by an atomic force microscope is 50 to 250% (5), and The ratio (Rv (fluororesin sheet-like material) / Rp (metal foil)) of the absolute value of the maximum valley depth (Rv) when the surface state of the same surface of the fluororesin sheet-like material is measured by an atomic force microscope and the maximum peak height (Rp) when the surface of the metal foil in contact with the fluororesin sheet-like material is measured by an atomic force microscope is 50 to 200% (6), and the amount of functional group (C=O) measured by a scanning X-ray photoelectron spectrometer (XPS) on the same surface of the fluororesin sheet-like material is preferably 2.0% or more. It is preferable that the laminate is such that the functional groups present on the surfaces of the metal foil and the fluororesin sheet-like material in the micro region are likely to be at an appropriate distance to form bonds, and further, the amount of functional groups contributing to adhesion is within a suitable range. In the case of a laminate in which one surface of the fluororesin sheet-like material is in contact with the metal layer, on the contact surface, it may satisfy the above physical properties. In the case of a laminate in which both surfaces of the fluororesin sheet-like material are in contact with the metal layer, at least one surface may satisfy the above physical properties, and particularly, it is preferable that both surfaces satisfy the above physical properties. When measured by a scanning X-ray photoelectron spectrometer (XPS), the amount of the functional group (C=O) on the same surface of the fluororesin sheet-like material is 2.0% or more. This laminate is suitable.

[0111] In the laminate of the present disclosure, by being a laminate that satisfies the above requirements, the functional groups present on the surfaces of the metal foil and the fluororesin sheet-like material in the micro region are likely to be at an appropriate distance to form bonds, and further, the amount of functional groups contributing to adhesion is within a suitable range, which is advantageous. In the case of a laminate in which one surface of the fluororesin sheet-like material is in contact with the metal layer, on the contact surface, it may satisfy the above physical properties. In the case of a laminate in which both surfaces of the fluororesin sheet-like material are in contact with the metal layer, at least one surface may satisfy the above physical properties, and particularly, it is preferable that both surfaces satisfy the above physical properties. This is advantageous.

[0112] In the case of a laminate in which one surface of the fluororesin sheet-like material is in contact with the metal layer, on the contact surface, it may satisfy the above physical properties. In the case of a laminate in which both surfaces of the fluororesin sheet-like material are in contact with the metal layer, at least one surface may satisfy the above physical properties, and particularly, it is preferable that both surfaces satisfy the above physical properties. In the case of a laminate in which both surfaces of the fluororesin sheet-like material are in contact with the metal layer, at least one surface may satisfy the above physical properties, and particularly, it is preferable that both surfaces satisfy the above physical properties. It is particularly preferable that both surfaces satisfy the above physical properties.

[0113] The laminate disclosed herein has an adhesive strength of 0 between the measuring surface of the fluororesin sheet material and the metal layer. It is preferable that the density is 5 N / cm or higher. In other words, each of the laminates described above satisfies at least the above physical properties of a fluororesin. The adhesive strength at the surface where the sheet material and the metal layer are in contact is 0.5 N / cm or more. This is preferable. By meeting the requirements described above, such adhesive strength can be achieved. By increasing the strength to 1 N / cm or more, and further to 2 N / cm or more, copper-clad laminates and circuit boards can be used. It can be used suitably in this way. Note that the adhesive strength referred to here is the adhesive strength measured under the conditions described in the examples. be.

[0114] (Layer structure of the laminate) The laminate of this disclosure has a two-layer structure consisting of the above-described fluororesin sheet material and a metal layer. It may also be a structure of three or more layers, having two or more layers of either or both of these. Furthermore, a structure consisting of three or more layers, including a layer (X) other than the metal layer and the fluororesin sheet material. It is also acceptable to build it.

[0115] Layers other than the metal layer and the fluororesin sheet material (X) include polyimide and liquid crystal polymer. Examples include polyphenylene sulfide, cycloolefin polymers, and polystyrene. Examples of thermosetting resins include epoxy resin, bismaleimide, and polyphenylene oxide. Examples include polyphenylene ethers, divinylbenzene, and polybutadiene. It can be done.

[0116] If the laminate of this disclosure has the above layer (X), the layer configuration is a metal layer / fluororesin sheet element The material can be arranged as layer / layer(X). A fluororesin sheet can be applied to one or both sides of layer(X). A laminate of a material layer / metal layer may be present.

[0117] (Method of manufacturing a laminate) The method for manufacturing the laminate of this disclosure is described in detail below. To obtain the laminate of this disclosure, the metal foil used as a material must have high smoothness. Furthermore, it is preferable to adjust the conditions in the process of bonding with the fluororesin sheet material. It seems so.

[0118] When bonding the above metal foil and the fluororesin sheet material, heating is required, but When manufacturing the laminate shown, it is preferable to heat it to a temperature below the melting point of the fluororesin. Specifically, it is preferable to set the temperature to 70-300°C. Preferably, it is 70-250°C. Furthermore, it is preferable to set the temperature to 70-200°C. The fluororesin sheet material disclosed herein can be bonded at a temperature below the melting point of the fluororesin. It has excellent adhesion to metal layers. Regarding the heat treatment process, the method is either roll-to-roll lamination, or coating on metal foil. Alternatively, the coated fluororesin may be heat-treated. In other words, by lowering the heating temperature, the warping of the metal foil is suppressed, and the metal foil and fluororesin In the process of bonding sheet-like materials, the smoothness of the bonding surface is less likely to be impaired. It is preferable in that respect. As a result, cosmetic defects and peeling are eliminated, improving the reliability of the circuit board.

[0119] In the manufacturing of the laminate according to this disclosure, the method for bonding the metal foil and the fluororesin sheet material is: Although not particularly limited, from the viewpoint of excellent manufacturing efficiency, a roll-to-roll lamination method is particularly preferred.

[0120] By manufacturing in a roll-to-roll manner, cost reduction can be achieved, and it is also preferable in that a long laminated body can be obtained. When manufacturing a laminated body by such a method, the width of the laminated body is not particularly limited, but it is preferably 200 mm or more.

[0121] In addition, in the case of a laminated body in which a metal foil is adhered to the surface-treated surface of a fluororesin sheet-like material that has been surface-treated only on one side, in order to improve the adhesiveness between the laminated body and other materials, surface modification may be separately performed on the surface of the fluororesin sheet-like material that has not been surface-treated.

[0122] The laminated body of the present disclosure has good adhesiveness between the metal layer and the fluororesin sheet-like material and is resistant to peeling. Therefore, since the surface smoothness of the adhesive surface can be maintained, it has the advantage of low transmission loss. For this reason, it can be suitably used for circuit boards and the like. In particular, it can be particularly suitably used for circuit boards of high-frequency circuits. The present disclosure also includes a circuit board having the above-described fluororesin sheet-like material or laminated body of the present disclosure.

[0123] In the present disclosure, the high-frequency circuit does not simply consist of a circuit that transmits only high-frequency signals, but also includes a transmission path that converts a high-frequency signal into a low-frequency signal and outputs the generated low-frequency signal to the outside, or a transmission path for supplying a power source for driving high-frequency compatible components, etc., and a circuit in which transmission paths for transmitting signals that are not high-frequency signals are also provided on the same plane. In addition, it can also be used as a circuit board such as an antenna or a filter. ​​​​​​​

Example

[0124] Hereinafter, the present disclosure will be specifically described based on examples. In the following examples, unless otherwise specified, "parts" and "%" represent "parts by mass" and "mass %", respectively.

[0125] (Example 1) [Method for manufacturing fluororesin sheet-like material] As the fluororesin, PFA (TFE / PPVE copolymer, composition: TFE / PPVE = 95. 8 / 4.2 (mass %), MFR: 15.8 g / 10 min, melting point: 305 °C, number of unstable end groups : 297 per 10 main-chain carbon atoms 6 is used and charged into an extruder at 360 °C, extruded from a T-die with a width of 1 700 mm, taken up by a metal cooling roll, and further wound around a winding core to obtain a fluororesin sheet-like material with a width of 1300 mm and a thickness of 12 μm. [Surface treatment] Surface treatment (corona discharge) is performed on both sides of the obtained roll-shaped fluororesin sheet-like material. While flowing an inert gas (nitrogen / Ar ratio 60 / 40) containing 0.50 vol% of vinyl acetate and 0.70 vol% of carbon dioxide gas near the discharge electrode of the corona discharge device and the roll-shaped ground electrode, the fluororesin sheet -like material is continuously passed along the roll-shaped ground electrode, and the discharge amount is 200 W·min / m to corona-discharge both sides of the fluororesin sheet-like material, and a long-strip fluororesin sheet -like material is wound into a roll to obtain a surface-treated sample. Then, evaluation is carried out. 2

[0126] (Example 2) A surface-treated sample was obtained in the same manner as in Example 1, except that the carbon dioxide gas was 0.50 vol%, the nitrogen / Ar ratio of the inert gas was 70 / 30, and the discharge amount was 80 W·min / m 2 ​​​​

[0127] (Example 3) Carbon dioxide 0.20% by volume, inert gas nitrogen / Ar ratio 60 / 40, discharge rate 70 W·min / m 2 A sample was obtained that was surface-treated in the same manner as in Example 1, except that the same procedure was followed.

[0128] (Example 4) Carbon dioxide 0.30% by volume, inert gas nitrogen / Ar ratio 50 / 50, discharge rate 80 W·min / m 2 A sample was obtained that was surface-treated in the same manner as in Example 1, except that the same procedure was followed.

[0129] (Example 5) Carbon dioxide at 0.50% by volume, inert gas nitrogen / Ar ratio at 90 / 10, discharge rate at 30 0W·min / m 2 A sample was obtained that was surface-treated in the same manner as in Example 1, except that the same procedure was followed.

[0130] (Example 6) Carbon dioxide 0.30% by volume, inert gas nitrogen / Ar ratio 80 / 20, discharge rate 70 W·min / m 2 A sample was obtained that was surface-treated in the same manner as in Example 1, except that the same procedure was followed.

[0131] (Example 7) Carbon dioxide at 0.80% by volume, inert gas nitrogen / Ar ratio at 80 / 20, discharge rate at 20 0W·min / m 2 A sample was obtained that was surface-treated in the same manner as in Example 1, except that the same procedure was followed.

[0132] (Example 8) As a fluororesin, fluorinated PFA1 (TFE / PPVE copolymer, composition: TFE / PPV) E = 94.1 / 5.9 (mass%), MFR: 16.2g / 10min, Melting point: 305℃, Concern Number of terminal groups: Undetectable (main chain carbon number 10) 6Example 6, except that less than 1 per unit was used. A sample prepared in the same manner was obtained.

[0133] (Example 9) As a fluororesin, fluorinated PFA2 (TFE / PPVE copolymer, composition: TFE / PPV) E = 96.1 / 3.9 (mass%), MFR: 16.2g / 10min, Melting point: 305℃, Concern Number of terminal groups: Undetectable (main chain carbon number 10) 6 Example 6, except that less than 1 per unit was used. A sample prepared in the same manner was obtained.

[0134] (Comparative Example 1) Using an inert gas (nitrogen) containing 0.50% vinyl acetate, the discharge rate was set to 100W. min / m 2 A sample was obtained that was surface-treated in the same manner as in Example 1, except that the same procedure was followed.

[0135] (Comparative Example 2) An inert gas containing 1.50% by volume of carbon dioxide and 0.50% by volume of vinyl acetate (nitrogen / A Using an r ratio of 35 / 65, the discharge rate was 150 W·min / m 2 Except for the above, this is Example 1. Samples were obtained with the same surface treatment.

[0136] (Comparative Example 3) Using an inert gas containing 0.50% vinyl acetate by volume (nitrogen / Ar ratio 30 / 70) The discharge rate is 40W·min / m 2 A sample that was surface-treated in the same manner as in Example 1, except that it was modified as shown. I got the lure.

[0137] (Method for measuring maximum peak height (Rp) and maximum peak depth (Rv)) For each sheet and copper foil in the examples and comparative examples, the maximum peak height (Rp) and maximum peak depth were determined. The value of s(Rv) was determined by the following method. Furthermore, for fluororesin sheets, the inner surface of the roll after surface treatment is used, and for copper foil, the inner surface of the copper foil roll is used (unscratched). The surface temperature was measured. Using a scanning atomic force microscope AFM5000 (manufactured by Hitachi High-Tech Corporation), under the conditions shown below: Surface Rp and surface Rv were measured for the surface of the surface-treated sheet and copper foil in a 10 μm square area. . Cantilever: SI-DF20 (tip radius < 10 nm, spring constant 15 N / m) Measurement mode: AC mode Scanning frequency: 1Hz Pixel count: 256 x 256 The results are shown in Table 3.

[0138] (Method for measuring the oxygen element ratio) Scanning X-ray Photoelectron Spectroscopy (XPS / ESCA) PHI5000VersaProb Using eII (manufactured by ULVAC-PHI, Inc.), the surface treatment was performed under the conditions shown below. The oxygen element ratio on the inner surface of a roll of fluororesin sheet material was measured. The target elements for detection are silicon, nitrogen, and silicon, with the oxygen element ratio being C1s, O1s, F1s, N1s, Si2p. This was determined from the composition ratio. Radiation source: Monochromatized AlKα Beam diameter: 100 μm X-ray output: 25W Measurement area: 1000μm x 300μm Pass energy: 23.5 eV Detection angle: 45° The results are shown in the table.

[0139] (Method for measuring the amount of functional groups (C=O)) The C1s narrow spectrum obtained by the above XPS was processed using MultiPak software ( Using ULVAC-PHI, the signal was separated into five peaks under the conditions shown in Table 2 above, and these The amount of functional groups (C=O) was determined from the ratio. The full width at half maximum (FMAX) of peaks 1 to 4 was standardized to 1.83, and the peak The half-width of 5 was adjusted to match the shape of the original spectrum. The results are shown in Table 3.

[0140] (Adhesion strength with copper foil) Fluororesin sheet material and electrolytic copper foil CF-T9DA-SV-18 (thickness 18μm / Rz0 Using 0.85μm (manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.), each was cut into the predetermined shape. The copper foil and the fluororesin sheet material are arranged in that order, with the unroughened surface of the copper foil being the fluororesin sheet material. The fluororesin sheet material is placed so that it is in contact with the other surface, and the inner surface of the rolled material after surface treatment is the upper surface. Yes, a vacuum heat press machine (model number: MKP-1000HVWH-S7 / Mikado Technos Co., Ltd.) (Manufactured by the company) Press temperature 120℃, preheating time 120 seconds, pressurizing pressure 10MPa, pressurizing time 1 The laminate was obtained by heat pressing for 200 seconds. The resulting laminate was cut to a width of 10 mm, and an aluminum plate was attached to the bottom surface with adhesive tape. Using a Silon universal testing machine (manufactured by Shimadzu Corporation), the laminated material was tested at a speed of 50 mm per minute. The copper foil is peeled off by grasping a 10mm wide copper foil at a 90° angle to the plane and pulling it. The strength was measured, and the obtained value was defined as the adhesive strength. The measurement was taken at any point in the roll-shaped fluororesin sheet material, at the center and on both sides. At all three locations 100mm from each end, 100m in the direction of travel The laminate was fabricated at 5 locations at intervals of m, and the average value of 15 measurement points is shown. The results are shown in Table 3.

[0141] (Adhesive strength after thermal shock test) A fluororesin sheet material, and further, a prepreg material, prepreg R-5680(J) (Thickness 132μm) (Manufactured by Panasonic Corporation), copper foil CF-T9DA-SV-1 8 (thickness 18μm) (manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.), CF-V9S-SV-12 (thickness Using 12μm (manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.), each piece is cut to the specified shape. From top to bottom: CF-T9DA-SV-18 (unroughened surface facing down), fluororesin sheet material (surface) (The inner surface of the roll after processing is the top surface), prepreg R-5680(J), CF-V9S-SV- Stack the materials in the order of 12 (rough bottom surface to top surface), and press conditions: temperature 200°C, pressurizing time 75 The laminate was obtained by hot pressing at a pressure of 3.0 MPa for several minutes. The resulting laminate was subjected to a thermal shock test (low temperature exposure -55°C for 15 minutes, temperature transition time 5 minutes, high temperature). After bleaching at 125°C for 15 minutes (500 cycles), it is cut into 10mm widths and then processed into CF-V. An aluminum plate was attached to the 9S-SV-12 side with adhesive tape, and the adhesive strength with the copper foil was measured in the same manner as before. The adhesive strength was measured according to the law. The measurement was taken at any point in the roll-shaped fluororesin sheet material, at the center and left and right sides. At all three locations 100mm from each end, 100mm in the direction of travel The laminate was fabricated at five different locations, and the result is the average of 15 measurement points. The results are shown in Table 3.

[0142] [Table 3]

[0143] From the results in Table 3, the fluororesin sheet material of the example was found to be at a temperature below the melting point of fluororesin. The adhesion was good. [Industrial applicability]

[0144] The fluororesin sheet material of this disclosure can be suitably used as a circuit board.

Claims

1. On at least one surface, the foot satisfies at least one of the following (1) and (2) A sheet-like material made of raw resin. (1) The maximum peak height (Rp) when the surface condition is measured by atomic force microscopy is 30 to 1 50 nm (2) When the surface condition is measured by atomic force microscopy, the maximum peak depth (Rv) is -30 to -120nm

2. The fluororesin sheet material according to claim 1, satisfying both (1) and (2) above.

3. Fluororesin is tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA) Claim 2, which is either ) or tetrafluoroethylene-hexafluoropropylene (FEP). A sheet-like material made of fluororesin.

4. On the surface of at least one of the surfaces in contact with the metal layer, the following (3) and (4) A laminate comprising a fluororesin sheet-like material that satisfies at least one of the conditions, and a metal layer. (3) The maximum peak height (Rp) when the surface condition is measured by atomic force microscopy is 30 to 15 0 nm (4) When the surface condition is measured by atomic force microscopy, the maximum peak depth (Rv) is -30 to - 120 nm

5. The claim is that the Rz of the surface of the metal layer in contact with the fluororesin sheet material is 1.5 μm or less. The laminate described in 4.

6. Claim 4, wherein the fluororesin sheet material satisfies both of (3) and (4) above. A laminated structure.

7. The claim is that the Rz of the surface of the metal layer in contact with the fluororesin sheet material is 1.5 μm or less. The laminate described in 6.

8. The above measurement surface of the fluororesin sheet material is analyzed using a scanning X-ray photoelectron spectroscopy (XPS) analyzer. The oxygen element ratio measured by is 1.35 atomic% or more, according to any of claims 4 to 7. The laminate described below.

9. The above measurement surface of the fluororesin sheet material is analyzed using a scanning X-ray photoelectron spectroscopy (XPS) analyzer. The amount of functional groups (C=O) measured by any of claims 4 to 7 is 2.0% or more. A laminated structure.

10. A laminate comprising a fluororesin sheet-like material and a metal layer, The surface of at least one of the surfaces in contact with the metal layer is less than (5) and (6) below At least one of the above conditions is met, and the above measurement surface of the fluororesin sheet material is measured using scanning X-ray light. The oxygen element ratio measured by electron spectroscopy (XPS) is 1.35 atomic% or less. The laminated structure is shown above. (5) In the state before lamination of the fluororesin sheet material, at least the surface in contact with the metal layer The maximum peak height (Rp) when the surface state on one side is measured by atomic force microscopy and , in the state before lamination of the metal foil, the metal on the surface in contact with the fluororesin sheet material. The ratio of the maximum peak height (Rp) when the foil surface is measured by atomic force microscopy (Rp(fluorine) The ratio of resin sheet material to Rp (metal foil) is 50-250%. (6) In the state before lamination of the fluororesin sheet material, at least the surface in contact with the metal layer The maximum peak depth (Rv) when the surface state on one side is measured by atomic force microscopy is The absolute value and the surface in contact with the fluororesin sheet material in the state before lamination of the metal foil. The ratio (Rv) of the maximum peak height (Rp) when the surface of a metal foil is measured using an atomic force microscope. The ratio of (fluororesin sheet material) to Rp (metal foil) is 50-200%.

11. The laminate according to claim 10, satisfying both (5) and (6) above.

12. A laminate comprising a fluororesin sheet-like material and a metal layer, The surface of at least one of the surfaces in contact with the metal layer is less than (5) and (6) below At least one of the above conditions is met, and the same surface of the fluororesin sheet material is scanned with X-ray beam. The amount of functional groups (C=O) measured by electron spectroscopy (XPS) is 2.0% or more. Laminated structure. (5) In the state before lamination of the fluororesin sheet material, at least the surface in contact with the metal layer The maximum peak height (Rp) when the surface state on one side is measured by atomic force microscopy and , in the state before lamination of the metal foil, the metal on the surface in contact with the fluororesin sheet material. The ratio of the maximum peak height (Rp) when the foil surface is measured by atomic force microscopy (Rp(fluorine) The ratio of resin sheet material to Rp (metal foil) is 50-250%. (6) In the state before lamination of the fluororesin sheet material, at least the surface in contact with the metal layer The maximum peak depth (Rv) when the surface state on one side is measured by atomic force microscopy is The absolute value and the surface in contact with the fluororesin sheet material in the state before lamination of the metal foil. The ratio (Rv) of the maximum peak height (Rp) when the surface of a metal foil is measured using an atomic force microscope. The ratio of (fluororesin sheet material) to Rp (metal foil) is 50-200%.

13. The laminate according to claim 12, satisfying both (5) and (6) above.

14. Fluororesin is tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA) Claim 10, which is either ) or tetrafluoroethylene-hexafluoropropylene (FEP) A laminate as described in any of the following 13.

15. Claim 10, wherein the Rz of the surface of the metal layer in contact with the fluororesin sheet material is 1.5 μm or less. A laminate as described in any of the following 13.

16. The adhesive strength between the above-mentioned fluororesin sheet material and the above-mentioned metal layer is 0.5 N / cm or more. A laminate according to any one of claims 10 to 13.

17. A fluororesin sheet-like substrate according to any one of claims 1 to 3, or claims 4 to 7, 10 to A circuit board having a laminate as described in any of the 13.

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