TW202103934A - Laminate, method for manufacturing printed circuit board, printed circuit board, and antenna - Google Patents

Abstract

The present invention provides a laminate (metal clad laminate) which comprises a dielectric layer that has a low water absorption rate and excellent dielectric characteristics, heat resistance, and adhesion, and a metal foil layer, and which has excellent properties as materials or the like of printed circuit boards such as flexible printed circuit boards and rigid printed circuit boards. The laminate has at least a three-layer structure and includes the metal foil layer, a non-thermoplastic polyimide layer P, and a tetrafluoroethylene polymer layer F, at least one of the outermost layers being the metal foil layer. The layer F is present on at least one surface of the layer P. The layer P has a water absorption rate of less than 1.5%, and the absolute value of the coefficient of linear expansion thereof is 25 ppm/DEG C or less.

Description

Laminated body, manufacturing method of printed circuit board, printed circuit board and antenna

The present invention relates to a laminated body, a manufacturing method of a printed circuit board, a printed circuit board and an antenna.

With the development of the information and communication society, the amount of data transmission has increased. As a result, the frequency of radio waves used for information transmission continues to rise. The transmission path through which the electric signal passes is, for example, a printed circuit board. If a high-frequency electrical signal is passed through this transmission path, the higher the frequency, the greater its degradation (loss). In order to reduce the loss of electrical signals, the dielectric materials used in the printed circuit board require the characteristics of low dielectric constant, low dielectric loss tangent, and low water absorption. Examples of the above-mentioned dielectric material include tetrafluoroethylene-based polymers. However, if a tetrafluoroethylene-based polymer is used, the dimensional stability and mechanical strength of the printed circuit board tend to decrease. A non-thermoplastic polyimide is proposed as an alternative to the above-mentioned tetrafluoroethylene-based polymer (see Patent Documents 1 to 3). Prior art literature Patent literature

Patent Document 1: International Publication No. 2016/159060 Patent Document 2: International Publication No. 2018/061727 Patent Document 3: Japanese Patent Laid-Open No. 2018-150544

[The problem to be solved by the invention]

The printed circuit board formed by the laminate with non-thermoplastic polyimide as the dielectric layer has excellent dielectric properties due to the characteristics on the molecular skeleton. However, the inventors of the present invention first learned the following: the dielectric properties of the above-mentioned printed circuit board are still unstable due to the water absorption of non-thermoplastic polyimide. In addition, the inventors of the present invention have also understood the following: According to the above-mentioned characteristics, the heat resistance of non-thermoplastic polyimide is not yet sufficient. If the above-mentioned laminate is used for the float soldering step as the mounting step of the printed circuit board, the The electrical body layer is easy to peel off or swell, and it is difficult to efficiently manufacture a printed circuit board. The object of the present invention is to provide a laminate (metal foil-clad laminate), which has a dielectric layer and a metal foil layer, the dielectric layer is a composite of non-thermoplastic polyimide and tetrafluoroethylene polymer , And excellent dielectric properties, heat resistance and adhesion, and low water absorption. In addition, an object of the present invention is to provide a printed circuit board with excellent physical properties and reduced transmission loss, a manufacturing method thereof, and an antenna. [Technical means to solve the problem]

The present invention has the following aspects. [1] A laminate having a metal foil layer, a non-thermoplastic polyimide layer P, and a tetrafluoroethylene polymer layer F, and at least a three-layer structure in which at least one of the outermost layers is a metal foil layer Moreover, the layer F is present on at least one side of the layer P, the water absorption rate of the layer P is less than 1.5%, and the absolute value of the linear expansion coefficient is 25 ppm/°C or less. [2] The layered body as described in [1], which is a layered body having a structure of at least four layers in which the layer F is present on both sides of the layer P, respectively. [3] The laminate as described in [1] or [2], wherein the root mean square roughness of the surface of the metal foil layer is 0.25 μm or more. [4] The laminate according to any one of [1] to [3], wherein the thickness of the metal foil layer is 2 to 30 μm. [5] The laminate according to any one of [1] to [4], wherein the non-thermoplastic polyimide-based glass transition temperature is 280°C or higher.

[6] The laminate according to any one of [1] to [5], wherein the non-thermoplastic polyimide has a tensile modulus of 0.2 GPa or more at 320°C. [7] The laminate according to any one of [1] to [6], wherein the non-thermoplastic polyimide has a density of 0.20 to 0.35. [8] The layered product according to any one of [1] to [7], wherein the thickness of the layer P is 10 to 100 μm. [9] The laminate according to any one of [1] to [8], wherein the tetrafluoroethylene-based polymer is a hot-melt tetrafluoroethylene-based polymer having a melting temperature of 260 to 320°C. [10] The layered product according to any one of [1] to [9], wherein the thickness of the layer F is 1 to 38 μm.

[11] The laminate as described in any one of [1] to [10], wherein the laminate is in contact with the layer F when the laminate is maintained in an atmosphere of 24° C. and a relative humidity of 50% for 24 hours The dielectric constant of the above-mentioned layer P is 2.8 or less, and the dielectric loss tangent is 0.004 or less. [12] The laminate as described in any one of [1] to [11], wherein the laminate is in contact with the layer F when the laminate is maintained in an atmosphere of 85° C. and a relative humidity of 85% for 72 hours The dielectric constant of the above-mentioned layer P is 2.8 or less, and the dielectric loss tangent is 0.007 or less. [13] A method of manufacturing a printed circuit board, which comprises subjecting the metal foil layer of the laminate as described in any one of [1] to [12] to an etching process to form a transmission circuit to obtain a printed circuit board. [14] A printed circuit board having a layer P of non-thermoplastic polyimide, a layer F of a tetrafluoroethylene polymer present on at least one side of the above-mentioned layer P, and a transmission layer present on at least one side of the above-mentioned layer F Circuit, and the water absorption rate of the above-mentioned layer P is less than 1.5%, and the absolute value of the linear expansion coefficient is 25 ppm/℃ or less. [15] An antenna formed of the printed circuit board as described in [14] above. [Effects of Invention]

According to the present invention, it is possible to obtain a printed circuit board that is not susceptible to the influence of water and whose transmission loss is reduced. In addition, it is possible to obtain a laminated body suitable for efficient production of the above-mentioned printed circuit board, and having a dielectric layer and a metal foil layer with excellent dielectric properties, heat resistance, and adhesiveness, and a low water absorption rate.

The following terms have the following meanings. The so-called "hot-melt polymer (resin)" means a polymer with melt fluidity, and it means that under a load of 49 N, there is a melt flow at a temperature higher than the melting temperature of the polymer by 20℃ or more. The speed is changed to 0.1～1000 g/10 minutes for the temperature polymer. Furthermore, the so-called "melt flow rate" means the melt mass flow rate (MFR, Melt mass-flow rate) of the polymer specified in JIS K 7210: 1999 (ISO 1133: 1997). The so-called "Glass Transition Point (Tg) of a polymer" refers to the value measured by analyzing the polymer using a dynamic viscoelasticity measurement (DMA, Dynamic Mechanical Analysis) method. The "melting temperature of the polymer" is the temperature corresponding to the maximum melting peak measured by the differential scanning calorimetry (DSC, Differential Scanning Calorimetry) method. "D50 of powder" is the cumulative 50% diameter of the powder based on the volume obtained by the laser diffraction scattering method. That is, the particle size distribution is measured by the laser diffraction scattering method, the total volume of the cluster of particles is set to 100%, and the cumulative curve is obtained, and the particle size at the point where the cumulative volume becomes 50% on the cumulative curve. "D90 of powder" is the cumulative 90% diameter of the powder based on the volume obtained by the laser diffraction scattering method. That is, the particle size distribution is measured by the laser diffraction scattering method, the total volume of the cluster of particles is set to 100%, and the cumulative curve is obtained, and the particle size at the point where the cumulative volume becomes 90% on the cumulative curve. The D50 and D90 of the powder are obtained by dispersing the powder in water and analyzing it by the laser diffraction scattering method using a laser diffraction scattering type particle size distribution measuring device (manufactured by Horiba Manufacturing Co., Ltd., LA-920 measuring device) . "Liquid viscosity" is the viscosity of the liquid measured at room temperature (25°C) at 30 rpm using a type B viscometer. The measurement is repeated 3 times, and the average value of the 3 measurements is obtained. "Ten-point average roughness of layer" is the value specified in the appendix JA of JIS B 0601:2013. "Root mean square roughness of layer" is the value specified in JIS B 0601:2013 (ISO 4287:1997, Amd.1:2009). "Film dielectric constant and dielectric loss tangent" unless otherwise specified, use a separation column dielectric resonator at a frequency of 10 GHz under an environment of 23℃±2℃ and relative humidity of 50±5% (SPDR, Split Post Dielectric Resonator) measured value. The same applies to "layer dielectric constant and dielectric loss tangent". "The tensile elastic modulus of the film" is a value measured at a measuring frequency of 10 Hz using a wide-area viscoelasticity measuring device. The so-called "unit" in the addition polymerization polymer (resin) means an atomic group based on 1 molecule of the above-mentioned monomer formed by the polymerization of a monomer. The unit may also be an atomic group directly formed by a polymerization reaction, or may be an atomic group formed by processing a polymer so that a part of the above-mentioned atomic group is converted into another structure. Hereinafter, the unit based on monomer a is also abbreviated as "monomer a unit". The so-called "unit" in the copolycondensation polymer (resin) means an atomic group derived from 1 molecule of each of the two monomers formed by the copolycondensation of two monomers of the copolycondensation. For example, in the non-thermoplastic polyimide in the present invention, each of the tetracarboxylic acid residue and the diamine residue is referred to as a unit.

The laminated system of the present invention has a metal foil layer, a non-thermoplastic polyimide layer P, and a tetrafluoroethylene polymer layer F, and at least one of the outermost layers is a metal foil layer with at least three layers, and A layer F is present on at least one side of the layer P described above. The water absorption rate of the layer P in the present invention is less than 1.5%, and the absolute value of the linear expansion coefficient of the layer P is 25 ppm/°C or less. In addition, hereinafter, the above-mentioned tetrafluoroethylene-based polymer is also referred to as "F polymer". The laminated body of the present invention (the same applies to the printed circuit board of the present invention) has low water absorption, and the dielectric properties, heat resistance, and excellent adhesion to the metal foil layer (transmission circuit in the case of a printed circuit board) may not be the reason why To be clear, consider as follows.

There is a layer F on at least one side of the layer P in the present invention. It is considered that since the F polymer has excellent dielectric properties and heat resistance, and has a low water absorption rate, this configuration improves the dielectric properties, heat resistance, and water absorption rate of the laminate. On the other hand, it is estimated that the F polymer has a large linear expansion coefficient as a whole, which tends to reduce the dimensional stability and adhesion of the laminate. In contrast, the layer P in the present invention has a linear expansion coefficient within a specific range and contains a non-thermoplastic polyimide layer. Non-thermoplastic polyimides are also called modified polyimides, which have non-thermoplastic block sites and have a lower density of imine groups. It is considered that the above-mentioned polyimide and the F polymer highly interact to improve the dimensional stability and adhesion of the laminate. As a result, the peeling of the metal foil layer is suppressed and the expansion of the laminate is suppressed during high-temperature processes such as the float soldering step.

Furthermore, the so-called "non-thermoplastic polyimide" means that even if heated, it does not exhibit softening and adhesion, and the storage modulus at 30°C measured with a dynamic viscoelasticity measuring device (DMA) is Polyimide with 1.0×10 ⁹ Pa or more and a storage modulus of 3.0×10 ⁸ Pa or more at 280°C. "Non-thermoplastic polyimide" is also the following polyimide: combining monomers and performing solution polymerization, drying the obtained solution (solution of polyimide precursor), and then making it imidize , The formed molded body (film, etc.) will maintain its shape when heated at 450°C for 1 minute. In addition, the so-called "thermoplastic polyimide" means the glass transition temperature (Tg) can be confirmed, and the storage modulus at 30℃ measured by DMA is 1.0×10 ⁹ Pa or more, and the storage at 280℃ Polyimide with a modulus of less than 3.0×10 ^{8 Pa.} "Thermoplastic polyimide" is also the following polyimide: combining monomers and performing solution polymerization, drying the obtained solution (solution of the polyimide precursor), and then making it imidize, When the formed molded body (film, etc.) is heated at 450°C for 1 minute, it deforms or fuses due to wrinkles or elongation.

The laminated system of the present invention has a metal foil layer, a layer P, and a layer F, and at least one outermost layer is a metal foil layer (metal foil-clad laminate). The layered body of the present invention may have layer F on only one side of layer P, or layer F on both sides of layer P. In the former case, the layer F may exist only on the surface on the metal foil layer side of the layer P, or the layer F may exist only on the surface (the outermost surface) opposite to the metal foil layer side of the layer P.

As the aspect of the laminated body of the present invention, there may be mentioned: an aspect having a metal foil layer, a layer F, and a layer P in this order; an aspect having a metal foil layer, a layer P, and a layer F in this order; an aspect having a metal foil in this order The aspect of layer, layer F, layer P, and layer F. If there is layer F on the outermost surface, a laminate with lower water absorption can be obtained. If there is layer F between the metal foil layer and layer P, heat resistance (especially float solder resistance) and dielectric properties can be obtained A more excellent laminate. As the aspect of the laminated body of the present invention, it is preferable to have the last aspect of the layer F on both sides of the layer P, respectively. Furthermore, the laminate of the present invention may be a metal foil-clad laminate having metal foil layers on both sides. Examples of the metal foil-clad laminate on both sides include: a metal foil layer, a layer F, a layer P, and a metal foil layer in this order; and a metal foil layer, a layer F, a layer P, a layer F, and a metal foil layer in this order The state. As the double-sided metal foil-clad laminate, it is preferable to have the layer F on both sides of the layer P, respectively. In the laminate of the present invention, it is preferable that at least a part of the layer P is in contact with at least a part of the layer F, and it is particularly preferable that the entire single surface of the layer P is in contact with the entire single surface of the layer F. In this case, not only the adhesion between the layer P and the layer F is further improved, but the water absorption rate is also likely to decrease significantly.

In the present invention, the ratio of the thickness of the layer P to the thickness of the layer F is preferably 1 or more. The above-mentioned ratio is preferably 2 or more, more preferably 4 or more, and particularly preferably 8 or more. The above-mentioned comparison is preferably 100 or less, more preferably 50 or less, more preferably 35 or less, and particularly preferably 20 or less. In this case, it is easy to balance the dimensional change (warpage, etc.) of the laminate during heating and the suppression of interfacial peeling, the water absorption of the laminate, and the dielectric properties of the laminate. Furthermore, as in the last aspect mentioned above, when the laminate of the present invention contains a plurality of layers F, the thickness of the above-mentioned layer F means the thickness of each layer F. The thickness of the metal foil layer in the present invention is preferably 2-30 μm, particularly preferably 3-25 μm. In addition, the ratio of the thickness of the layer F to the thickness of the metal foil layer is preferably 0.5 or more, and more preferably 1 or more. The above-mentioned comparison is preferably 10 or less, and more preferably 5 or less. In this case, it is easy to balance the dimensional change (warpage, etc.) of the laminate during heating and the suppression of interfacial peeling, the water absorption of the laminate, and the dielectric properties of the laminate.

As the material of the metal foil in the present invention, copper, copper alloy, stainless steel, nickel, nickel alloy (including 42 alloy), aluminum, aluminum alloy, titanium, titanium alloy, etc. can be cited. As the material of the metal foil, copper and copper alloy are preferred. Examples of copper foil include rolled copper foil and electrolytic copper foil. An anti-rust layer (oxide film such as chromate, etc.), a heat-resistant layer, etc. may also be formed on the surface of the metal foil. The surface of the metal foil layer can also be treated with a silane coupling agent. In this case, the entire surface of the metal foil can be treated, or a part of the surface of the metal foil can be treated. The ten-point average roughness of the surface of the metal foil layer (hereinafter also referred to as "Rzjis") is preferably 0.2-2.5 μm. In this case, it is easy to obtain a laminate having good adhesion between the metal foil layer and the layer F or the layer P and having excellent dielectric properties.

The root mean square roughness (hereinafter also referred to as "Rq") of the surface of the metal foil layer is preferably 0.05 μm or more, more preferably 0.10 μm or more, and still more preferably 0.12 μm or more. Rq is preferably 0.25 μm or less, more preferably 0.20 μm or less. If the Rq of the metal foil layer is within the above range, the adhesion between the metal foil layer and each layer becomes good, and the effective conductivity of the interface becomes higher, and the transmission loss is more likely to be reduced. Furthermore, the so-called effective conductivity of the interface refers to the conductivity at the contact interface between the resin of the layer and the metal foil layer. Since the electrical signal flows near the interface, the higher the high frequency electrical signal, the higher the effective conductivity of the interface and the lower its transmission loss. The effective conductivity of the interface is calculated according to the following Groisse approximation. [Number 1]

The symbols in the formula indicate the following meanings. σ _c : effective conductivity σ: conductivity of the conductor s: skin thickness of the current flow h: root-mean-square roughness of the surface of the conductor. Furthermore, since the conductivity of the conductor is determined by the type of metal of the metal foil, the surface of the conductor is The root mean square roughness is determined based on the Rq of the metal foil layer, and the skin thickness is determined based on the frequency. Therefore, the smaller the Rq of the metal foil layer, the greater the effective conductivity of the interface.

In addition, the metal foil layer may be a metal foil with a carrier containing two or more metal foils. Examples of the metal foil with carrier include carrier copper foil (thickness: 10 to 35 μm) and ultra-thin copper foil (thickness: 2 to 5 μm) laminated on the carrier copper foil via a peeling layer. The copper foil. After the layers are sequentially laminated on the ultra-thin copper foil side of the above-mentioned carrier-attached copper foil, and only the carrier copper foil is peeled off, a laminate having the ultra-thin copper foil can be easily formed. If this laminate is used, it is possible to form a fine pattern using an ultra-thin copper foil layer as a plating seed layer through a Modified Semi-Additive Process (MSAP) process. As the peeling layer, from the viewpoint of heat resistance, a metal layer containing nickel or chromium, or a multilayer metal layer in which the metal layer is laminated is preferable. In the case of the above-mentioned peeling layer, the carrier metal foil can be easily peeled from the ultra-thin metal foil even after a step of 300°C or higher. As a specific example of the metal foil with the carrier, the trade name "FUTF-5DAF-2" manufactured by Futian Metal Foil & Powder Industry Co., Ltd. can be cited.

The layer P in the present invention contains non-thermoplastic polyimide. As long as the effect of the present invention is not impaired, the layer P may contain other components. As specific examples of other components, from the viewpoint of further improving the dielectric properties, powders of F polymers such as PTFE and PFA can be cited, and from the viewpoint of reducing the coefficient of linear expansion, glass strands, aromatics can be cited Fillers such as polyamide cut strands, polybenzoxazole cut strands, silica, alumina, and magnesium oxide. The layer P preferably contains non-thermoplastic polyimide as a main component, and preferably contains 80-100% by mass of non-thermoplastic polyimide.

The water absorption rate of the layer P is less than 1.5%, preferably 1.2% or less. The water absorption rate of the layer P is preferably more than 0%. The absolute value of the linear expansion coefficient of the layer P is 25 ppm/°C or less, preferably 22 ppm/°C or less, more preferably 15 ppm/°C or less, and particularly preferably 10 ppm/°C or less. The absolute value of the coefficient of linear expansion of the layer P is preferably more than 0 ppm/°C. The layer P is preferably formed of a non-thermoplastic polyimide film (hereinafter also referred to as "mPI film"). In this case, the physical properties of the layer P are regarded as the physical properties of the original mPI film. The coefficient of linear expansion of the layer P is obtained as follows: using a thermomechanical analysis device, the non-thermoplastic polyimide film used in the formation of the layer P is measured at a load: 29.4 mN, and a measurement atmosphere: nitrogen atmosphere After heating up from 0°C to 400°C at 10°C/min, cooling it back to 10°C at 40°C/min, and then heating it up from 10°C to 200°C at 10°C/min to obtain the linear expansion coefficient at this time. The surface of the mPI film can be treated with a silane coupling agent, etc., and can also be modified by corona treatment, plasma treatment, etc. In addition, the surface of the mPI film can be roughened or annealed.

In particular, if the surface of the mPI film is plasma treated, it becomes possible to laminate with layer F at a lower temperature, and it is easier to reduce the deformation of layer P. The plasma treatment is preferably atmospheric pressure plasma treatment or vacuum plasma treatment. The vacuum plasma treatment is preferably a continuous discharge glow discharge treatment (that is, the so-called low-temperature plasma treatment) at a gas pressure of 0.1 to 1330 Pa (preferably 1 to 266 Pa). In this case, if a frequency of 10 kHz to 2 GHz and an electric power of 10 W to 100 kW are applied between the discharge electrodes, stable glow discharge treatment can be performed. From the viewpoint of adjusting the wetting tension of the surface of the mPI film, the discharge power density of the vacuum plasma treatment is preferably 5 to 400 W·min/m ² . Examples of the gas used include helium, neon, argon, nitrogen, oxygen, carbon dioxide, hydrogen, air, water vapor, and the like. One type of gas may be used alone, or two or more types may be mixed and used. The gas is preferably argon, nitrogen, hydrogen, or a mixed gas of argon, nitrogen, hydrogen, and the like from the viewpoint of further improving the interlayer adhesion strength. The time of the vacuum plasma treatment is preferably 5 to 60 seconds from the viewpoint of further improving the adhesion strength between layers.

In the atmospheric piezoelectric slurry treatment, the glow discharge treatment under the atmosphere of an inert gas (argon, nitrogen, helium, etc.) at 0.8-1.2 atmospheric pressure is preferable. The inert gas can also be mixed with a trace amount of active gas (oxygen, hydrogen, carbon dioxide, ethylene, tetrafluoroethylene, etc.). The gas used is preferably argon, nitrogen, hydrogen, and a mixed gas thereof from the viewpoint of further improving the adhesion strength between layers. The voltage, frequency of power supply and plasma treatment time in atmospheric piezoelectric plasma treatment are usually 1～10 kV, 1～20 kHz, 0.1 second～10 minutes in sequence. The discharge power density of atmospheric piezoelectric slurry treatment is preferably 5 to 400 W·min/m ² .

The non-thermoplastic polyimide in the present invention preferably contains non-thermoplastic block sites. The so-called non-thermoplastic block part means that the polyimide precursor obtained by solution polymerization of only the monomer constituting the block part is evaluated in the same way as the definition method of the non-thermoplastic polyimide mentioned above. A block site formed by a combination of monomers of polyimide that maintains the shape. On the other hand, the term "thermoplastic block site" means that the polyimide precursor obtained by solution polymerization of only the monomer constituting the block site is evaluated in the same way as the definition method of the non-thermoplastic polyimide described above. At this time, the block site is formed by the combination of monomers forming the polyimide that does not maintain its shape. Furthermore, when judging whether the block part is thermoplastic or non-thermoplastic, in the case of rigidity, it is only necessary to collect the fragments and heat, and judge according to the state of maintaining the shape.

The glass transition temperature of the non-thermoplastic polyimide in the present invention is preferably 280°C or higher, more preferably 290°C or higher. The glass transition temperature is preferably 450°C or lower, particularly preferably 400°C or lower. In this case, the layer F and the layer P can be laminated at a lower temperature, and it is easy to obtain a laminated body with more excellent dimensional stability.

The non-thermoplastic polyimide in the present invention has a tensile modulus of elasticity at 320°C of preferably 0.2 GPa or more, preferably 0.4 GPa or more. The tensile modulus of elasticity is preferably 10 GPa or less, more preferably 5 GPa or less. In this case, even if the laminate is exposed to a heating operation and a cooling operation in order to process it, it has excellent handling properties. That is, if the tensile elastic modulus of the non-thermoplastic polyimide is more than the above lower limit, the shrinkage of the layer F is effectively alleviated due to the elasticity of the layer P during heating and cooling, and the laminate is less likely to be wrinkled and easy Improve the physical properties (surface smoothness, etc.) of the processed products obtained. The above tendency becomes significant when the content of the F polymer in the layer F or the thickness of the layer F is large. In addition, if the tensile modulus of non-thermoplastic polyimide is less than the above upper limit, the flexibility of the laminate is likely to be more excellent.

The non-thermoplastic polyimide in the present invention preferably has a density of 0.20 to 0.35. If the density of the imine group is the above upper limit, the water absorption rate of the non-thermoplastic polyimide becomes lower, and it is easier to suppress the change in the dielectric properties of the laminate. If the above-mentioned imidine group density is within the above-mentioned lower limit, it not only functions as a polar group, but also improves the adhesion between the layer P and the layer F, and the water absorption rate tends to decrease significantly. Moreover, if the density of the imine group of the non-thermoplastic polyimide is within the above-mentioned range, it becomes more difficult to generate wrinkles during the processing of the laminate. The above-mentioned tendency of non-thermoplastic polyimide to have a lower glass transition temperature becomes significant. Furthermore, the density of the iminium group is the polyimidization of the polyimide precursor. In the polyimide, the molecular weight per unit (140.1) of the iminium portion divided by the polyimide The value derived from the unit's molecular weight. For example, a polyimide precursor containing two components of pyromellitic dianhydride (molecular weight: 218.1) 1 mol and 3,4'-oxydianiline (molecular weight: 200.2) 1 mol is imidized The resulting polyimide (molecular weight per unit: 382.2) has a density of 140.1 divided by 382.2 and the value obtained is 0.37.

The non-thermoplastic polyimide in the present invention preferably contains a compound selected from 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, p-phenylenediamine, 4,4'- Bis(4-aminophenoxy)biphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,3-bis(4-aminophenoxy)benzene, 1 ,3-bis(3-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 4,4'-diaminophenoxy, 3,4'-diamine Diphenyl ether, 4,4'-(1,3-phenylene diisopropylidene) bisaniline, 2,2'-n-propyl-4,4'-diaminobiphenyl and 4-amine A plurality of aromatic diamines in the group consisting of phenyl-4'-aminobenzoic acid esters, and selected from the group consisting of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid Acid dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,3,2',3'-biphenyltetracarboxylic dianhydride, 4,4'-oxydiphthalate Formic acid dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 1,4-phenylene bis(trimellitic acid monoester) dianhydride, p-phenylene bis Triester dianhydride, 1,4-phenylene bis(trimellitic acid monoester) dianhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, and 2,3, Units formed by multiple aromatic acid dianhydrides in the group consisting of 6,7-naphthalenetetracarboxylic dianhydride. In this case, not only the non-thermoplasticity of the non-thermoplastic polyimide is improved, but the adhesion between the layer P and the layer F is further improved, and the water absorption rate is easily reduced significantly. The non-thermoplastic polyimide preferably contains 80 mol% or more of the above-mentioned units with respect to all the units. The upper limit is 100 mol%.

Furthermore, among non-thermoplastic polyimides, meta-phenylenediamine, 1,5-diaminonaphthalene, benzidine, 3,3'-dimethoxybenzidine, p-xylylenediamine, 4, 4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 1,4-bis( 3-methyl-5-aminophenyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2- Bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-bis(trifluoromethyl)benzidine, 3,3'-bis(trifluoromethyl)benzidine, 2, Other diamines such as 2-bis(4-aminophenyl)hexafluoropropane are used as monomer components of the unit. These other diamines may be used individually by 1 type, and may use 2 or more types together.

Furthermore, in the non-thermoplastic polyimide, pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, pyridine-2,3,5,6-tetracarboxylic acid, 4,4'- Oxydiphthalic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3',3,4'-biphenyltetracarboxylic acid, 3,3',4,4'-di Benzophenone tetracarboxylic acid, 5,5'-[1-methyl-1,1-ethanediylbis(1,4-phenylene)bisoxy]bis(isobenzofuran-1,3 -Diketone), 4,4'-(hexafluoroisopropylidene)diphthalic anhydride and other tetracarboxylic acids or their derivatives as monomer components of the unit. These other tetracarboxylic acids or derivatives thereof may be used singly or in combination of two or more kinds.

The synthesis of the polyimide precursor (polyamide acid) in the production of non-thermoplastic polyimide is preferably carried out in the presence of a solvent. Specific examples of the solvent include: dimethyl sulfide, diethyl sulfide, N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethyl Acetamide, N,N-diethylacetamide, N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, phenol, cresol, xylenol, halogenated phenol, o- Hydroquinone, hexamethylphosphamide. The polyimide precursor is preferably prepared as a solution containing 5-40% by weight of the polyimide precursor based on the solid content. In addition, the viscosity of the solution in this case is preferably 100 to 1000 Pa·s. In addition, a part of the polyimide precursor in the solution can also be imidized.

The thickness of the layer P in the present invention is preferably 10-100 μm. The dielectric loss tangent of the layer P in the present invention at 10 GHz is preferably less than 0.008. The above-mentioned dielectric loss tangent preferably exceeds zero.

The layer F in the present invention contains F polymer. As long as the effect of the present invention is not impaired, the layer F may contain other components, and preferably contains F polymer as the main component, and preferably contains 80 to 100% by mass of F polymer. The layer F is preferably a layer formed by melting the F polymer (a layer of a molten molded product of the F polymer). In this case, since the layer F becomes non-porous, the heat insulation effect during heating in the float welding step is further improved, and the etching resistance is also easier to improve. The F polymer is preferably a hot-melt F polymer. In terms of not only improving the heat resistance and interlayer adhesion of the laminate, but also the water absorption rate is likely to decrease significantly, it is more preferably a melting temperature of 260-320°C. F polymer.

The F polymer in the present invention is a polymer having a unit (TFE unit) based on tetrafluoroethylene (hereinafter, also referred to as "TFE"). The F polymer can be a homopolymer of TFE, or a copolymer of TFE and a comonomer that can be copolymerized with TFE. The F polymer preferably has 90-100 mol% of TFE units with respect to all units constituting the polymer. The fluorine content of the F polymer is preferably 70 to 76% by mass, more preferably 72 to 76% by mass. Examples of F polymers include: polytetrafluoroethylene (PTFE), copolymers of TFE and ethylene (ETFE), copolymers of TFE and propylene, TFE and perfluoro(alkyl vinyl ether) (hereinafter also referred to as Copolymer of "PAVE") (PFA), copolymer of TFE and hexafluoropropylene (hereinafter, also referred to as "HFP") (FEP), TFE and fluoroalkyl ethylene (hereinafter, also referred to as "FAE") Copolymer, copolymer of TFE and chlorotrifluoroethylene. Furthermore, the copolymer may further have units based on other comonomers.

Preferred specific examples of the F polymer include low molecular weight PTFE, modified PTFE, FEP, and PFA. Furthermore, low molecular weight PTFE or modified PTFE also contains copolymers of TFE and very small amounts of comonomers (HFP, PAVE, FAE, etc.). The F polymer preferably has a TFE unit and a functional group. The functional group is preferably a carbonyl group-containing group, a hydroxyl group, an epoxy group, an amine group or an isocyanate group. The functional group may be contained in the unit in the F polymer, or may be contained in the terminal group of the main chain of the polymer. As the latter polymer, a polymer having a functional group as a terminal group derived from a polymerization initiator, chain transfer or the like can be cited. In addition, an F polymer having a functional group obtained by performing plasma treatment or radiation treatment on the surface of the F polymer layer can also be cited. The F polymer having a functional group is preferably an F polymer having a TFE unit and a unit having a functional group. The unit having a functional group is preferably a unit based on a monomer having a carbonyl group-containing group, a hydroxyl group, an epoxy group, an amine group, or an isocyanate group.

The monomer having a carbonyl group-containing group is preferably a cyclic monomer having an acid anhydride residue, a monomer having a carboxyl group, vinyl ester and (meth)acrylate, and more preferably a cyclic monomer having an acid anhydride residue body. Particularly preferred are itaconic anhydride, citraconic anhydride, 5-norene-2,3-dicarboxylic anhydride (another name: bicycloheptene dicarboxylic anhydride) and maleic anhydride. As a preferable specific example of the F polymer having a functional group, an F polymer having a TFE unit, a HFP unit, a PAVE unit or an FAE unit, and a unit having a functional group can be cited. Examples of PAVE include: CF ₂ =CFOCF ₃ , CF ₂ =CFOCF ₂ CF ₃ , CF ₂ =CFOCF ₂ CF ₂ CF ₃ , CF ₂ =CFOCF ₂ CF ₂ CF ₂ CF ₃ , CF ₂ =CFO(CF ₂ ) ₈ F. Examples of FAE include: CH ₂ =CH(CF ₂ ) ₂ F, CH ₂ =CH(CF ₂ ) ₃ F, CH ₂ =CH(CF ₂ ) ₄ F, CH ₂ =CF(CF ₂ ) ₃ H, CH ₂ =CF(CF ₂ ) ₄ H. The above-mentioned F polymer preferably has 90-99 mol% of TFE units, 0.5-9.97 mol% of HFP units, PAVE units or FAE units, and 0.01-3 mol% of all units constituting the polymer. The units with functional groups. As a specific example of the above-mentioned F polymer, the polymer described in International Publication No. 2018/16644 can be cited.

The thickness of the layer F is preferably 1 to 38 μm or less. The above-mentioned thickness is more preferably 2 μm or more. The above-mentioned thickness is preferably 35 μm or less, more preferably 30 μm or less. In this case, it is easy to suppress the dimensional change (warpage, etc.) and interface peeling of the laminate during heating, and further improve its heat resistance. Furthermore, if the thickness of the layer F is 1 μm or more, regardless of the configuration of the layer P, the transmission loss of the printed circuit board in the high-frequency region is greatly improved. If the thickness of the layer F is equal to or less than the upper limit, it is particularly easy to suppress the dimensional change (warpage, etc.) of the laminate during heating and interfacial peeling.

The specific structure of the laminate of the present invention includes the following laminates: at least one of the outermost layers is a copper foil layer, and layers F are present on both sides of the layer P, and at least a part of each layer F is in contact with at least a part of the layer P . More specifically, a laminate having a structure of copper foil layer/layer F/layer P/layer F and a laminate having a structure of copper foil layer/layer F/layer P/layer F/copper foil layer can be cited . Preferably, the thickness of the copper foil layer in the above configuration is 3-25 μm, the thickness of the layer F is independently 2-30 μm, the thickness of the layer P is preferably 10-100 μm, and the thickness of the layer F is relative to that of the copper foil The ratio of the thickness of the layers is preferably 0.5-5, and the ratio of the thickness of the above-mentioned layer P to the thickness of the layer F is preferably 1-50. In addition, the above-mentioned layer P is preferably a layer formed of an mPI film whose surface has been subjected to plasma treatment. In addition, the above-mentioned layer F is preferably a layer of hot-melt F polymer. The above-mentioned layer F may also be a layer formed by a layer of F polymer whose surface has been subjected to plasma treatment before lamination.

In the present invention, the layer P with layer F on at least one side (ie, the layer P with one side in contact with the layer F or the layer P with both sides in contact with the layer F) in the environment of normal temperature and humidity, the long-term continuity of electrical properties Excellent. As the laminate of the present invention, it is preferably a laminate having a dielectric constant of 2.8 or less when the layer P in contact with the layer F is kept in an atmosphere of 24°C and a relative humidity of 50% for 24 hours. Preferably, it is a laminate of 2.7 or less. Furthermore, the lower limit of the above-mentioned dielectric constant is preferably 2. In addition, it is preferable that when the laminate of the present invention is kept in an atmosphere of 24° C. and a relative humidity of 50% for 24 hours, the dielectric loss tangent of the layer P in contact with the layer F is a laminate of 0.004 or less. Preferably, it is a laminate of 0.003 or less. Furthermore, the lower limit of the above-mentioned dielectric loss tangent is preferably 0.0001.

In addition, the layer P in the present invention is also excellent in long-term durability of electrical characteristics under a high temperature and high humidity environment. As the laminated body of the present invention, it is preferable that the dielectric constant of the layer P in contact with the layer F is 2.8 or less when it is kept in an atmosphere of 85°C and 85% relative humidity for 72 hours, and more Preferably, it is a laminate of 2.7 or less. Furthermore, the lower limit of the above-mentioned dielectric constant is preferably 2. In addition, it is preferable that when the laminate of the present invention is kept in an atmosphere of 85°C and a relative humidity of 85% for 72 hours, the dielectric loss tangent of the layer P in contact with the layer F is less than 0.007, and more Preferably, it is a laminate of 0.006 or less. Furthermore, the lower limit of the above-mentioned dielectric loss tangent is preferably 0.0001.

The laminate of the present invention is preferably manufactured as follows: using a hot pressing method, a metal foil with a metal foil layer and a layer F is made of a resin-attached metal foil and an mPI film as the layer P is a layer F of the metal foil with a resin It is fused in a way opposite to the mPI film. At this time, the tensile elastic modulus of the non-thermoplastic polyimide in the mPI film at 320° C. is preferably 0.2 GPa or more, preferably 0.4 GPa or more. In addition, the tensile modulus of elasticity is preferably 10 GPa or less, more preferably 5 GPa or less. If the tensile modulus of non-thermoplastic polyimide is more than the above lower limit, when cooling is performed after hot pressing, the shrinkage of the layer F is likely to be effectively alleviated due to the elasticity of the layer P. As a result, wrinkles are less likely to occur in the laminate, and it is easier to obtain a laminate having more excellent physical properties such as surface smoothness. The above tendency becomes remarkable when the density of the non-thermoplastic polyimide group in the mPI film or the glass transition temperature is low. In addition, if the tensile elastic modulus of the non-thermoplastic polyimide is less than or equal to the above upper limit, the flexibility of the laminate is likely to be more excellent.

As a manufacturing method of the metal foil with resin mentioned above, the method of apply|coating the powder dispersion liquid of F polymer on the surface of a metal foil and manufacturing is mentioned. Specifically, the following method can be cited: a powder dispersion containing a powder containing F polymer (hereinafter, also referred to as "F powder"), a solvent, and a dispersant is applied to the surface of the metal foil, and then applied to the surface of the metal foil at 100 to 300 The metal foil layer is maintained in a temperature range of ℃ (hereinafter, also referred to as "holding temperature"), the solvent is removed, and the F polymer is fired in a temperature range exceeding the above temperature range to form a layer F on the surface of the metal foil.

The F powder preferably contains F polymer as a main component, and preferably contains 80 to 100% by mass of F polymer. The D50 of the F powder is preferably 0.05 to 6.0 μm, more preferably 0.2 to 3.0 μm. The D90 of the F powder is preferably 0.3-8 μm, more preferably 0.8-5 μm. By making the D50 or D90 of the F powder within the above range, the fluidity and dispersibility of the F powder becomes good, and the dielectric properties or heat resistance of the layer F can be further improved. The solvent is preferably a compound that does not volatilize instantaneously, but a compound that volatilizes when maintained at the above-mentioned holding temperature, more preferably a compound with a boiling point of 125 to 250°C. As the solvent, 1-butanol, 1-methoxy-2-propanol, 3-methoxy-N,N-dimethylpropanamide, 3-butoxy-N,N-di Methyl propanamide, N-methyl-2-pyrrolidone, γ-butyrolactone, cyclohexanone and cyclopentanone.

The dispersant is a compound having a hydrophilic group and a hydrophobic group, and is preferably a fluorine-based dispersant, a silicone-based dispersant or an acetylene-based dispersant, and more preferably a fluorine-based dispersant. The dispersant is preferably nonionic. As the fluorine-based dispersant, fluoromonool, fluoropolyol, fluorosilicone, and fluoropolyether are preferred. The fluoropolyol is preferably a copolymer of fluorine (meth)acrylate and (meth)acrylate having a hydroxyl group or a polyoxyalkylene hydroxyl group, and more preferably a copolymer having a polyfluoroalkyl group or a polyfluoroalkenyl group ( A copolymer of meth)acrylate and (meth)acrylate having a polyoxyalkylene monool group. The fluorosilicone is preferably a polyorganosiloxane containing a C-F bond in a part of the side chain. The fluoropolyether is preferably a compound in which a part of the hydrogen atoms of the polyoxyalkylene alkyl ether is substituted with fluorine atoms.

The powder dispersion may also contain components other than F powder, solvent and dispersant. Examples of other components include: thixotropy imparting agents, defoamers, inorganic fillers, reactive alkoxysilanes, dehydrating agents, plasticizers, weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, Brighteners, colorants, conductive agents, mold release agents, surface treatment agents, viscosity regulators, flame retardants, etc. In addition, the powder dispersion may contain resin components (thermosetting resins, thermoplastic resins, etc.) other than the F polymer. The ratio of the F powder in the powder dispersion is preferably 5 to 60% by mass. The ratio of the dispersant in the powder dispersion is preferably 0.1 to 30% by mass. The ratio of the solvent in the powder dispersion is preferably 15 to 65% by mass.

Examples of coating methods include: spray method, roll coating method, spin coating method, gravure coating method, micro gravure coating method, gravure offset method, knife coating method, contact coating method, bar coating method, Die nozzle coating method, fountain Meyer bar method, slit die nozzle coating method. It is also possible to adjust the state of the wet film by heating the metal foil with the wet film to the temperature below the above-mentioned temperature range before supplying the metal foil with the wet film to the holding temperature after coating. The adjustment can be carried out at a temperature where the solvent will not completely volatilize.

If the powder dispersion is applied to the surface of the metal foil and kept at the holding temperature, while volatilizing the solvent and decomposing the dispersant, a smooth coating formed by dense accumulation of F powder is formed. At this time, it is considered that the dispersant becomes easy to be bounced off by the F powder and becomes easy to flow on the surface. That is, it is considered that the state in which the dispersant segregates on the surface is formed by this holding. The maintaining atmosphere can be either under normal pressure or under reduced pressure. In addition, the atmosphere during holding may be any of an oxidizing atmosphere such as oxygen; a reducing atmosphere such as hydrogen; and an inert atmosphere such as helium, neon, argon, and nitrogen. The holding temperature is preferably a temperature range of 200 to 300°C. Within this range, the solvent is removed, and the partial decomposition and flow of the dispersant are effectively carried out, making it easier to cause surface segregation of the dispersant. The time for keeping at the holding temperature is preferably 0.1 to 10 minutes, particularly preferably 0.5 to 5 minutes.

In the production of the metal foil with resin, it is more preferable to fire the F polymer in a temperature region exceeding the holding temperature (hereinafter, also referred to as "baking temperature") to form a layer F on the surface of the metal foil. During firing, since the F powder is densely accumulated and the dispersant is effectively segregated on the surface, the F polymer is fused, so that a layer F with excellent smoothness and fusion properties is formed. Furthermore, if the powder dispersion contains a hot-melt resin, a layer F containing a mixture of F polymer and a soluble resin will be formed, and if the powder dispersion contains a thermosetting resin, a hardened product containing F polymer and thermosetting resin will be formed. Layer F. As the method of baking, there can be mentioned: the method of using an oven, the method of using a ventilated drying furnace, the method of irradiating hot rays such as infrared rays, etc. In order to improve the smoothness of the surface of the layer F, a heating plate, a heating roller, etc. can also be used for pressure. As the method of firing, firing can be carried out in a short time, and the method of irradiating far infrared rays is preferable because the far-infrared furnace is relatively small. During baking, infrared heating and hot air heating can also be combined.

The atmosphere during firing can be either under normal pressure or under reduced pressure. In addition, the atmosphere during the firing may be any of an oxidizing gas atmosphere such as oxygen; a reducing gas atmosphere such as hydrogen; and an inert gas atmosphere such as helium, neon, argon, and nitrogen, and preferably an inert gas atmosphere. The atmosphere at the time of firing is preferably an atmosphere that contains inert gas and has a low oxygen concentration, and preferably contains nitrogen and has an oxygen concentration (volume basis) of 300 ppm or less. The firing temperature is preferably more than 300°C, particularly preferably 330 to 380°C. In this case, the F polymer is easier to form a dense layer F. The time for keeping at the firing temperature is preferably 30 seconds to 5 minutes.

In the manufacture of the resin-attached metal foil, in order to suppress the linear expansion coefficient of the layer F, or to improve the fusion of the layer F, the surface of the obtained resin-attached metal foil layer F can also be surface-treated. Examples of surface treatments include annealing treatment, corona discharge treatment, atmospheric pressure plasma treatment, vacuum plasma treatment, ultraviolet ozone treatment, excimer treatment, chemical etching, silane coupling treatment, micro-roughening treatment, and the like. The temperature in the annealing treatment is preferably 80 to 190°C. The pressure during the annealing treatment is preferably 0.001 to 0.030 MPa. The annealing treatment time is preferably 10 to 300 minutes. Plasma irradiation devices for plasma treatment include: high frequency induction method, capacitive coupling electrode method, corona discharge electrode-plasma jet method, parallel plate type, remote plasma type, atmospheric piezoelectric plasma type, ICP (Inductively Coupled Plasma) type high-density plasma type, etc. As the gas used in the plasma processing, argon; a mixed gas of hydrogen and nitrogen; a mixed gas of hydrogen, nitrogen and argon can be cited. In this case, by adjusting the surface roughness of the layer F, it is easy to form fine irregularities.

The mPI film is preferably produced as follows: a solution of a polyimide precursor (polyamide acid) is subjected to a cyclization reaction to obtain a gel film, the gel film is dried, and then heat treated. Furthermore, by drying and heat treatment, the imidization of polyamide acid is carried out. As a method for the cyclization reaction, it can be used: casting the solution into a film, heating to carry out the cyclization reaction to obtain a gel film (thermal closed loop method); or mixing the catalyst and dehydrating agent in the solution, chemical The method of carrying out the cyclization reaction to obtain the gel film (chemical closed loop method). Examples of the catalyst include trimethylamine, triethylenediamine, dimethylaniline, isoquinoline, pyridine, and β-picoline. Examples of the dehydrating agent include acetic anhydride, propionic anhydride, butyric anhydride, and benzoic anhydride. The usage amount of the catalyst and the dehydrating agent is 1 mol, preferably 1.5-10 mol with respect to the amide group (or carboxyl) of the polyamide acid.

The obtained gel film is dried and heat-treated. The temperature during the drying treatment is preferably 220 to 300°C. In addition, from the viewpoint of suppressing the unevenness of the drying temperature in the film width direction, it is preferable to set the unevenness of the drying temperature to 20° C. or less. In addition, it is also possible to perform a stretching treatment on the gel film after the drying treatment. The temperature during the heat treatment is more preferably 300 to 550°C. The mPI film may be further subjected to surface treatments such as annealing treatment, corona treatment, plasma treatment, roughening treatment, and silane coupling agent treatment.

The pressing temperature during the hot pressing of the resin-coated metal foil and the mPI film is preferably 300°C to 350°C, more preferably 310°C to 330°C. Within this range, the thermal deformation of the mPI film can be suppressed, and the layer F and the mPI film can be firmly fused. The degree of vacuum during hot pressing is preferably 20 kPa or less. Within this range, mixing of bubbles into the metal foil layer, layer F, and layer P in the laminate, and degradation due to oxidation can be suppressed. Moreover, when performing hot pressing, it is preferable to raise the temperature after reaching the above-mentioned degree of vacuum. In this case, since the pressure bonding can be performed in the state before the layer F is softened, that is, the state before a certain degree of fluidity and adhesion is generated, the generation of bubbles can be prevented. The pressurizing pressure during hot pressing is preferably 0.2-10 MPa. Within this range, damage to the PI film can be suppressed, and the layer F and the mPI film can be firmly fused.

The laminate system of the present invention has excellent electrical properties, chemical resistance (etch resistance), heat resistance, and other physical properties such as a metal-clad laminate with layer F and layer P, which can be used as a material for flexible printed circuit boards or rigid printed circuit boards. A printed circuit board can be manufactured from the laminate of the present invention by the following methods: the metal foil layer of the laminate of the present invention is etched and processed into a conductive circuit (transmission circuit) of a specific pattern; or by the electrolytic plating method (semi- The additive method (SAP method, Semi-Additive Process), modified semi-additive method (MSAP method), etc.) is a method for processing the metal foil layer of the laminate of the present invention into a transmission circuit.

The printed circuit board of the present invention has a layer P, a layer F existing on at least one side of the above-mentioned layer P, and a transmission circuit existing on at least one side of the above-mentioned layer F, and the water absorption rate of the above-mentioned layer P is less than 1.5%. The absolute value of the coefficient of linear expansion of P is below 25 ppm/℃. The constitution of the printed circuit board of the present invention, the types of the layer P and the layer F, and the like are the same as the content of the laminate of the present invention, including the preferable range. As the structure of the printed circuit board of the present invention, for example, the structure of the transmission circuit/layer F/layer P, the structure of the transmission circuit/layer F/layer P/layer F, the transmission circuit/layer F/layer P/layer F/ The structure of the transmission circuit.

In the manufacture of the printed circuit board, after the transmission circuit is formed, an interlayer insulating film may be formed on the transmission circuit, and the transmission circuit may be formed on the interlayer insulating film. The interlayer insulating film can also be formed by, for example, the powder dispersion in the present invention. In the manufacture of printed circuit boards, solder resist can also be laminated on the transmission circuit. The solder resist can be formed by the powder dispersion in the present invention. In the manufacture of the printed circuit board, the cover film can also be laminated on the transmission circuit. The cover film can also be formed by the powder dispersion in the present invention. As a specific aspect of the printed circuit board, a multilayer printed circuit board obtained by multilayering the laminate of the present invention or the printed circuit board of the present invention can be cited.

As a preferable aspect of the multilayer printed circuit board, an aspect having one or more of the following constitutions can be cited: the outermost layer system layer F, and the metal foil layer, the layer F, and the layer P in this order. The metal foil layer in the above aspect is preferably partly removed to form a transmission circuit. In addition, there may be a transmission circuit formed by removing part of the metal foil layer between the layer F and the layer P. The multilayer printed circuit board of the above aspect has the layer F on the outermost layer and is excellent in heat resistance. Specifically, even at a high temperature of 250 to 300° C., the expansion or peeling of the interface is unlikely to occur. Especially when a transmission circuit is formed, that is, when a part of the metal foil layer is removed and the exposed layer F has a contact surface with other layers, the above tendency tends to become significant. It is believed that the reason is that the surface roughness of the metal foil layer is transferred to the surface of the layer F and the surface roughness of the layer F produced by the surface roughness of the layer F exhibits an anchoring effect when it is in contact with other layers. As a result, even if no hydrophilization treatment such as plasma treatment is performed, each interface is firmly fused, and it is possible to suppress interface expansion or interface peeling, especially the expansion or peeling of the outermost layer when heated.

As a preferable aspect of the multilayer printed circuit board, an aspect having one or more of the following constitutions can also be cited: the outermost layer system layer P, and the metal foil layer, the layer F, and the layer P in this order. The metal foil layer in the above aspect is preferably partly removed to form a transmission circuit. In addition, there may be a transmission circuit formed by removing part of the metal foil layer between the layer F and the layer P. In the multilayer printed circuit board of the above aspect, even if it has the layer P in the outermost layer, the heat resistance is excellent, and even at a high temperature of 250 to 300° C., expansion or peeling of the interface is unlikely to occur. Especially when a transmission circuit is formed, that is, when a part of the metal foil layer is removed and the exposed layer F has a contact surface with other layers, the above tendency tends to become significant. It is believed that the reason is that the surface roughness of the metal foil layer is transferred to the surface of the layer F and the surface roughness of the layer F produced by the surface roughness of the layer F exhibits an anchoring effect when it is in contact with other layers. As a result, even if no hydrophilization treatment such as plasma treatment is performed, the respective interfaces are firmly fused, and the expansion or peeling of the interface, especially the expansion or peeling of the outermost layer, can be suppressed during heating. The multilayer printed circuit board in these aspects is useful as a printed circuit board having excellent resistance to floating soldering.

As mentioned above, although the laminated body of this invention, the manufacturing method of a printed circuit board, a printed circuit board, and an antenna were demonstrated, this invention is not limited to the structure of the said embodiment. The laminated body, the printed circuit board, and the antenna of the present invention may be added with any other configuration to the configuration of the above-mentioned embodiment, and may be replaced with any configuration that performs the same function. Moreover, the manufacturing method of the printed circuit board of this invention may add other arbitrary steps to the structure of the said embodiment, and may replace it with arbitrary steps which perform the same function. Example

Hereinafter, the present invention will be described in detail with examples, but the present invention is not limited to these. The abbreviations of monomer and solvent have the following meanings. BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride ODPA: 4,4'-oxydiphthalic anhydride PMDA: Pyromellitic dianhydride PBTA: p-phenylene bis trimellit dianhydride PDA: p-phenylenediamine BAPP: 2,2'-bis[4-(4-aminophenoxy)phenyl]propane BAPB: 4,4'-bis(4-aminophenoxy)biphenyl PPBA: 4,4'-(1,3-phenylene diisopropylidene) bisaniline m-TB: 2,2'-dimethyl-4,4'-diaminobiphenyl TPE-R: 1,3-bis(4-aminophenoxy)benzene TFE: Tetrafluoroethylene PPVE: Perfluoropropyl vinyl ether NAH: 5-norethene-2,3-dicarboxylic acid anhydride (bicycloheptene dicarboxylic acid anhydride) NMP: N-methyl-2-pyrrolidone

[Example 1 (Reference example)] Preparation example of non-thermoplastic polyimide film [Example 1-1] mPI film 1 mPI film 1 is an unstretched film of non-thermoplastic polyimide (glass transition temperature: 298°C, density of amide group: 0.34). The non-thermoplastic polyimide is obtained as follows: select BPDA (75 mol%) , ODPA (15 mol%) and PMDA (15 mol%) as acid anhydride monomers, and PDA (70 mol%), BAPP (15 mol%) and BAPB (15 mol%) as diamine monomers Firstly, BPDA and PDA are solution polymerized, and then ODPA, PMDA, BAPP, and BAPB are added to polymerize them, and then they are imidized by chemical ring-closure method.

[Example 1-2] mPI film 2 mPI film 2 is an unstretched film of non-thermoplastic polyimide (glass transition temperature: 298°C, density of amide group: 0.26). The non-thermoplastic polyimide is obtained as follows: select PMDA (9 mol%) And BPDA (91 mol%) as the acid anhydride monomer, choose m-TB (15 mol%) and TPE-R (85 mol%) as the diamine monomers, so that all monomers are polymerized in solution, and the chemical ring is closed. Method to make its imidization.

[Example 1-3] mPI film 3 mPI film 3 is an unstretched film of non-thermoplastic polyimide (glass transition temperature: 420°C, density of amide group: 0.38). The non-thermoplastic polyimide is obtained as follows: select BPDA (100 mol%) As the acid anhydride monomer, PDA (100 mol%) was selected as the diamine monomer, all the monomers were subjected to solution polymerization, and the chemical ring-closure method was used to imidize them.

[Example 1-4] mPI film 4 mPI film 4 is an unstretched film of non-thermoplastic polyimide (glass transition temperature: 268°C, density of amide group: 0.18). The non-thermoplastic polyimide is obtained as follows: select BPDA (9 mol%) And PBTA (91 mol%) as the acid anhydride monomers, and m-TB (15 mol%) and PPBA (85 mol%) are selected as the diamine monomers, so that all monomers are polymerized in solution, and the chemical ring-closure method is used to make Its imidization. [Example 1-5] mPI film 5 Non-thermoplastic polyimide (manufactured by SKC Kolon PI, "FS-200", glass transition temperature: 310°C, density of imide group: 0.25). Table 1 summarizes the physical properties of each film.

[Table 1] mPI film 1 2 3 4 5 Thickness [μm] 50 50 50 50 50 Use polyimide Glass transition temperature [℃] 298 280 420 250 310 Density of imine group 0.34 0.26 0.38 0.18 0.28 Water absorption rate [%] 1.20 1.00 1.50 0.60 1.00 Dielectric constant 3.1 2.9 3.6 2.7 3.4 Dielectric loss tangent 0.006 0.005 0.010 0.005 0.004 Coefficient of linear expansion [ppm/℃] 10 twenty two 12 26 18 Tensile modulus of elasticity [GPa] 0.5 0.1 7 0.5 0.3

In addition, the physical properties of each polyimide and film were measured by the following methods. ＜Glass transition temperature＞ Using a dynamic viscoelasticity measuring device (manufactured by SII Nano Technology, "DMS6100"), analyze the polyimide film, and plot the ratio of the loss elastic modulus to the storage elastic modulus, that is, the loss positive connection (tanδ) versus temperature At this time, the temperature at which tanδ is the maximum value is set as the glass transition temperature of polyimide. The measurement conditions are set as follows: sample measurement range: width 9 mm, distance between clamps: 20 mm, measurement temperature: 0℃～440℃, heating rate: 3℃/min, measurement atmosphere: air atmosphere, strain amplitude: 10 μm , Measuring frequency: 5 Hz, minimum tension/compression force: 100 mN, tension/compression gain: 1.5, initial value of force amplitude: 100 mN.

＜Linear expansion coefficient＞ Using a thermomechanical analysis device (manufactured by SII Nano Technology, "TMA/SS6100"), the polyimide film (width: 3 mm, length: 10 mm) was heated from 0°C to 400°C at 10°C/min , Cool down to 10°C at 40°C/min, and then increase the temperature from 10°C to 200°C at 10°C/min, and obtain the linear expansion coefficient at this time. The measurement load was set to 29.4 mN, and the measurement atmosphere was set to air atmosphere. ＜Water absorption rate＞ The measurement is performed by the method described later. ＜Tensile modulus of elasticity＞ A wide-area viscoelasticity measuring device (manufactured by RHEOLOGY CO., LTD, "DVE RHEO SPECTOLER") was used to measure the tensile modulus of elasticity at 320°C. The measurement frequency is set to 10 Hz.

[Example 2 (Reference example)] Preparation example of powder dispersion of F polymer [Example 2-1] Dispersion 1 Dispersion 1 is a dispersion in which powder of F polymer 1 is dispersed in NMP. It is obtained as follows: Put into a crucible a TFE unit containing 98.0 mol%, 0.1 mol%, and 1.9 mol%, 50 parts by mass of powder (D50: 2.6 μm, D90: 7.1 μm) of F polymer 1 (melting temperature: 300°C) having an acid anhydride group of NAH unit and PPVE unit, 3 parts by mass of nonionic fluoropolyol, and NMP 47 parts by mass, zirconia balls were put into the crucible, and the crucible was rotated at 150 rpm for 1 hour.

[Example 2-2] Dispersion 2 Dispersion 2 is a dispersion in which the powder of F polymer 2 is dispersed in NMP. It is obtained as follows: Put into a crucible sequentially containing 98.0 mol%, 2.0 mol% of TFE units and PPVE units. Functional group F polymer 2 (melting temperature: 305°C) powder (D50: 3.5 μm, D90: 9.2 μm) 50 parts by mass, 3 parts by mass of nonionic fluoropolyol, and N-methyl-2-pyrrole 47 parts by mass of pyridone (NMP), zirconia balls were put into the crucible, and the crucible was rotated at 150 rpm for 1 hour.

[Example 3 (Reference Example)] Preparation Example of Copper Foil with Resin [Example 3-1] Preparation Example of Copper Foil with Resin 1 1 Apply to electrolytic copper foil 1 (thickness: 18 μm, Rzjis: 1.0 μm, Rq: 0.21 μm, manufactured by Fukuda Metal Foil Industry Co., Ltd., "CF-T4X-SV-18") to form a liquid coating. Then, the liquid coating film was passed through a drying oven at 120° C. for 5 minutes to be heated and dried to obtain a dry coating film. After that, the dry film was heated at 380°C for 3 minutes in a nitrogen oven. ^{Thereby, the resin-coated copper foil 1 in which the layer F 1} (thickness: 25 μm) containing the polymer 1 was formed on the surface of the electrolytic copper foil 1 was obtained. The water absorption rate ^{of layer F 1} measured after etching the electrolytic copper foil 1 was 0.01%. In addition, the surface roughness of the copper foil used for the adjustment of the resin-coated copper foil was measured by the following method. <Surface Roughness of Copper Foil> Using a contact surface roughness meter (manufactured by Tokyo Precision Co., Ltd., "SURFCOM NEX001"), the Rzjis and Rq values of the surface (matte surface) of the copper foil were measured. The measuring terminal uses a terminal with a tip radius of 2 μm and a cone (cone angle: 60°). The critical value is set to 0.8 mm and λs to 2.5 μm. The reference length of the roughness curve is set to 0.8 mm. The evaluation length is set to 4.0 mm.

[Example 3-2] Preparation example of copper foil 2 with resin, except that Dispersion 2 was used instead of Dispersion 1, and the operation was performed in the same manner as copper foil 1 with resin to obtain a polymer containing F 2 layer F ² (thickness: 25 μm) copper foil 2 with resin. The water absorption rate ^{of layer F 2} measured after etching the electrolytic copper foil 1 was 0.01%.

[Example 3-3] Preparation example of copper foil 3 with resin The reverse gravure coating method was used to coat a varnish containing 10% by mass of aromatic thermoplastic polyimide by a roll-to-roll method The electrolytic copper foil 1 forms a liquid coating. Then, the liquid coating was passed through a drying oven at 120°C for 5 minutes, and at 200°C for 10 minutes, and heated and dried to obtain a dry coating. ^{Thereby, the resin-coated copper foil 3 in which the aromatic thermoplastic polyimide layer PI 1} (thickness: 25 μm) is formed on the surface of the electrolytic copper foil 1 is obtained. The water absorption rate ^{of layer PI 1} measured after etching the electrolytic copper foil 1 was 1.5%. In addition, the water absorption of each layer after etching was measured by the method described later.

[Example 3-4] Preparation example of copper foil 4 with resin Changed the copper foil to electrolytic copper foil 2 (thickness: 18 μm, Rzjis: 1.2 μm, Rq: 0.28 μm, manufactured by Mitsui Metal Mining Co., Ltd., "TQ-M7-VSP-18"). In addition, with resin The same operation was performed on the copper foil 1 to obtain a copper foil 4 with resin. [Example 3-5] Preparation example of copper foil 5 with resin The copper foil was changed to electrolytic copper foil 3 (thickness: 18 μm, Rzjis: 0.6 μm, Rq: 0.14 μm, manufactured by Mitsui Metal Mining Co., Ltd., "TQ-M4-VSP-18"). In addition, with resin The same operation was performed on the copper foil 1 to obtain a copper foil 5 with resin.

[Example 4] Manufacturing example of laminated body [Example 4-1] Manufacturing example of laminated body 1 The copper foil 1 with resin is placed on each of the two sides of the mPI film 1 ^{so that the layer F 1 faces each other, and vacuum is performed} Hot pressing (pressing temperature: 320℃, pressing pressure: 2 MPa, pressing time: 2 minutes) to obtain a layer P ¹ (with electrolytic copper foil 1 (thickness: 18 μm)) and non-thermoplastic polyimide 1 The mPI film 1, thickness: 50 μm), and a laminate ^{1 having a layer F 1} (thickness: 25 μm) of F polymer 1 on both sides of the layer P 1. The laminate 1 is a laminate having a structure of electrolytic copper foil 1/layer F ¹ /layer P ¹ /layer F ¹ /electrolytic copper foil 1. Furthermore, before vacuum hot pressing, the surface of the mPI film 1 is subjected to a high-frequency voltage of 40 kHz (discharge power density: 300 W·min/m ² ) by using 95% by volume of argon gas and 5% by volume of hydrogen gas. Vacuum plasma treatment (vacuum degree: 20 Pa) of mixed gas (flow rate: 2000 sccm) of volume%, and surface treatment.

[Example 4-2] The manufacturing example of the laminate 2 used copper foil 2 with resin instead of copper foil 1 with resin, except that the same procedure as in Example 4-1 was carried out to obtain an electrolytic copper foil 1/ Layer F ² /Layer P ¹ /Layer F ² /Electrolytic copper foil 1 laminated body 2. [Example 4-3] The manufacturing example of the laminate 3 used the mPI film 2 instead of the mPI film 1, except that the operation was carried out in the same manner as in Example 4-1 to obtain an electrolytic copper foil 1/layer F ¹ /layer P ² ( A laminate 3 composed of mPI film 2)/layer F ¹ /electrolytic copper foil 1.

[Example 4-4] The manufacturing example of the laminate 4 used the mPI film 3 instead of the mPI film 1, except that the operation was carried out in the same manner as in Example 4-1 to obtain an electrolytic copper foil 1/layer F ¹ /layer P ³ ( A laminate 4 composed of mPI film 3)/layer F ¹ /electrolytic copper foil 1. [Example 4-5] The manufacturing example of the laminate 5 used the mPI film 4 instead of the mPI film 1, but the same procedure as in Example 4-1 was carried out to obtain an electrolytic copper foil 1/layer F ¹ /layer P ⁴ ( A laminate 5 composed of mPI film 4)/layer F ¹ /electrolytic copper foil 1.

[Example 4-6] The manufacturing example of the laminate 6 used the resin-coated copper foil 3 instead of the resin-coated copper foil 1. Except for this, the same procedure as in Example 4-1 was carried out to obtain an electrolytic copper foil 1/ A laminate ^{6 composed of layer PI 1} /layer P ¹ /layer PI ¹ /electrolytic copper foil 1. [Example 4-7] The manufacturing example of the laminate 7 used the mPI film 5 instead of the mPI film 1. The operation was carried out in the same manner as in Example 4-1 except that the electrolytic copper foil 1/layer F ¹ /layer P ⁵ ( A laminate 7 composed of mPI film 5)/layer F ¹ /electrolytic copper foil 1.

[Example 4-8] Manufacturing example of laminate 8 Except having used the copper foil 4 with resin instead of the copper foil 1 with resin, it carried out similarly to Example 4-1, and obtained the laminated body 8. [Example 4-9] Manufacturing example of laminate 9 Except having used the copper foil 5 with resin instead of the copper foil 1 with resin, it carried out similarly to Example 4-1, and obtained the laminated body 9.

[Example 5] Evaluation example of laminated body Each laminate was evaluated based on the following evaluation items. ＜Peel strength＞ The laminate was cut into a width of 1 cm, and peeled at an angle of 90° at a speed of 50 mm/min, and the peel strength (kN/m) was measured. ＜Normal State-Electrical Characteristics＞ The copper foil of each laminate was removed by etching, and dried at 100° C. for 2 hours to prepare a measurement sample including a layer P with layers F on both sides. After keeping each measurement sample in an atmosphere of 24° C. and a relative humidity of 50% for 24 hours, the dielectric constant (normal state-dielectric constant) and dielectric loss tangent (normal state-dielectric loss tangent) were measured. ＜Humidification-Electrical Characteristics＞ After measuring the above-mentioned electrical characteristics, each measurement sample was further kept at 85° C. and a relative humidity of 85% for 72 hours. Measure the dielectric constant (humidification-dielectric constant) and dielectric loss tangent (humidification-dielectric loss tangent) of each measurement sample within 5 minutes after holding.

＜Water absorption rate＞ Measure according to the method of JIS K 7209: 2000A. First, the copper foil of the laminate cut into 10 cm squares is removed by etching to prepare a test piece. Next, the test piece was dried at 50°C for 24 hours, and then cooled in a desiccator. The mass of the test piece at this time is taken as the mass of the test piece before immersion. Thereafter, the dried test piece was immersed in pure water at 23°C for 24 hours. After that, the test piece was taken out of the pure water, and the moisture on the surface was quickly wiped off, and the mass measured within 1 minute was taken as the immersed mass of the test piece. Calculate the mass change rate of the test piece before and after immersion and use it as the "water absorption (measured value)" of the laminate. In addition, the value obtained by simply summing the water absorption of each layer of the layered body is referred to as the "water absorption (calculated value)".

＜Transmission loss＞ A transmission line is formed on each layered body to produce a printed circuit board. The formation of the transmission line uses a microstrip line. A vector network analyzer (manufactured by Keysight Technology, "E8361A") was used to process the 28 GHz signal in the printed circuit board, and the general test fixture was used as a probe to measure the S21 parameter representing the transmission loss. At this time, the characteristic impedance of the line is set to 50 Ω, and the length of the transmission line of the printed circuit board is set to 50 mm, and the transmission loss is measured. As a measure of transmission loss, "S21-Parameter", which is one of the circuit network parameters used to express the characteristics of high-frequency electronic circuits or high-frequency electronic parts, is used as the transmission loss value. Regarding this value, the closer the value is to 0, the smaller the transmission loss. The transmission loss value of the printed circuit board formed by the laminate that is not immersed in pure water is set as the "transmission loss before water absorption", and the printed circuit board formed by the laminate after being immersed in pure water at 23°C for 24 hours The transmission loss value is set to "transmission loss after water absorption".

＜Float soldering resistance＞ The laminate was cut into 5 cm squares, immersed in pure water at 24°C for 24 hours, and floated in a solder tank at 260°C for 30 seconds. The appearance of the laminate at that time was evaluated according to the following criteria. ○ (good): Swelling and peeling did not occur. △(Yes): Swelling occurs, and part of it peels off. × (not possible): Swelling and peeling occurred.

＜Warpage (undulation) after etching treatment＞ After etching and removing the copper foil of the laminate, it was placed on a flat glass, and the presence or absence of warpage (undulation) was evaluated based on the following criteria. ○ (Yes): No warpage (undulation) occurs. × (unavailable): There is warpage (undulation), and there is a part bulging from the glass. The results of each evaluation are summarized in Table 2 and Table 3.

[Table 2] Layered body 1 2 3 4 5 The composition of the layer between 2 electrolytic copper foils F ¹ /P ¹ /F ¹ F ² /P ¹ /F ² F ¹ /P ² /F ¹ F ¹ /P ³ /F ¹ F ¹ /P ⁴ /F ¹ Floor constitute Thickness [μm] 25/50/25 25/50/25 25/50/25 25/50/25 25/50/25 Layer P Water absorption rate [%] 1.20 1.20 1.00 1.50 0.60 Coefficient of linear expansion [ppm/℃] 10 10 twenty two 12 26 Layer F Water absorption rate [%] 0.01 0.01 0.01 0.01 0.01 Types of electrolytic copper foil Electrolytic copper foil 1 Electrolytic copper foil 1 Electrolytic copper foil 1 Electrolytic copper foil 1 Electrolytic copper foil 1 The normal state of the physical properties of the laminated body-the dielectric constant 2.7 2.7 2.6 2.9 2.5 Humidification-Dielectric Constant 2.7 2.7 2.6 3.0 2.5 Normal-Dielectric Loss Tangent 0.003 0.003 0.002 0.004 0.002 Humidification-Dielectric Loss Tangent 0.006 0.006 0.005 0.009 0.004 Peel strength [kN/m] 1.4 1.0 1.2 1.5 0.8 Water absorption (calculated value) [%] 0.48 0.48 0.40 0.59 0.24 Water absorption (measured value) [%] 0.30 0.30 0.25 0.45 0.12 Transmission loss before water absorption [dB] -0.82 -0.82 -0.78 -0.96 -0.78 Transmission loss after water absorption [dB] -1.11 -1.11 -0.98 -1.57 -0.85 Transmission loss ratio before and after water absorption 0.74 0.74 0.80 0.61 0.92 Float solder resistance 〇 △ 〇 X X Warpage after etching 〇 〇 〇 〇 X

[table 3] Layered body 6 7 8 9 The composition of the layer between 2 electrolytic copper foils PI ¹ /P ¹ /PI ¹ F ¹ /P ⁵ /F ¹ F ¹ /P ¹ /F ¹ F ¹ /P ¹ /F ¹ Floor constitute Thickness [μm] 25/50/25 25/50/25 25/50/25 25/50/25 Layer P Water absorption rate [%] 1.20 1.00 1.20 1.20 Coefficient of linear expansion [ppm/℃] 10 18 10 10 Layer F Water absorption rate [%] 1.5 0.01 0.01 0.01 Types of electrolytic copper foil Electrolytic copper foil 1 Electrolytic copper foil 1 Electrolytic copper foil 2 Electrolytic copper foil 3 The normal state of the physical properties of the laminated body-the dielectric constant 3.2 2.8 2.7 2.7 Humidification-Dielectric Constant 3.4 2.8 2.7 2.7 Normal-Dielectric Loss Tangent 0.007 0.002 0.003 0.003 Humidification-Dielectric Loss Tangent 0.016 0.005 0.006 0.006 Peel strength [kN/m] 0.5 1.1 1.6 0.8 Water absorption (calculated value) [%] 1.60 0.40 0.48 0.48 Water absorption (measured value) [%] 1.60 0.25 0.30 0.30 Transmission loss before water absorption [dB] -1.3 -0.90 -0.90 -0.74 Transmission loss after water absorption [dB] -2.65 -1.17 -1.22 -1.00 Transmission loss ratio before and after water absorption 0.49 0.77 0.74 0.74 Float solder resistance X 〇 〇 〇 Warpage after etching 〇 〇 〇 〇

Furthermore, the appearance of each laminate was confirmed visually, and as a result, no wrinkles appeared in the appearance of laminates other than the laminate 3. In the layered body 3, the generation of wavy wrinkles originating from the layer P was confirmed. Cut each laminate into a 5 mm square, bend it 180° under the condition of a radius of curvature (300 μm), apply a load (50 mN, 1 minute) from above, restore the bend, and check the appearance. As a result, in laminates 1 to 3 and laminates 5 to 9, there was no abnormal appearance at the crease, while in laminate 6, whitening appeared at the crease. [Industrial availability]

The laminate of the present invention is useful as a material for printed circuit boards. In addition, if the printed circuit board of the present invention is used, an antenna with excellent characteristics can be obtained. In addition, the Japanese patent application No. 2019-077829 filed on April 16, 2019, the Japanese patent application No. 2019-151453 filed on August 21, 2019, and those filed on October 25, 2019 The entire contents of the specification of Japanese Patent Application No. 2019-194515, the scope of patent application, and the abstract of the invention are quoted here and incorporated as the disclosure of the specification of the present invention.

Claims (15)

A laminate having a metal foil layer, a non-thermoplastic polyimide layer P, and a tetrafluoroethylene polymer layer F, and at least one of the outermost layers is a metal foil layer with at least three layers, and The layer F is present on at least one side of the layer P, the water absorption rate of the layer P is less than 1.5%, and the absolute value of the linear expansion coefficient is 25 ppm/°C or less. Such as the laminated body of claim 1, which is a laminated body in which at least four layers of the above-mentioned layer F are respectively present on both sides of the above-mentioned layer P. The laminate of claim 1 or 2, wherein the root mean square roughness of the surface of the metal foil layer is 0.25 μm or more. The laminate according to any one of claims 1 to 3, wherein the thickness of the metal foil layer is 2-30 μm. The laminate according to any one of claims 1 to 4, wherein the non-thermoplastic polyimide is a non-thermoplastic polyimide having a glass transition temperature of 280°C or higher. The laminate according to any one of claims 1 to 5, wherein the non-thermoplastic polyimide has a tensile modulus of 0.2 GPa or more at 320°C. The laminate according to any one of claims 1 to 6, wherein the non-thermoplastic polyimide has a density of 0.20 to 0.35. The layered body according to any one of claims 1 to 7, wherein the thickness of the above-mentioned layer P is 10-100 μm. The laminate according to any one of claims 1 to 8, wherein the tetrafluoroethylene-based polymer is a hot-melt tetrafluoroethylene-based polymer having a melting temperature of 260 to 320°C. The layered body according to any one of claims 1 to 9, wherein the thickness of the above-mentioned layer F is 1 to 38 μm. The layered body of any one of claims 1 to 10, wherein when the layered body is kept in an atmosphere of 24° C. and a relative humidity of 50% for 24 hours, the dielectric of the layer P in contact with the layer F The constant is 2.8 or less, and the dielectric loss tangent is 0.004 or less. The layered body of any one of claims 1 to 11, wherein when the layered body is kept in an atmosphere of 85°C and a relative humidity of 85% for 72 hours, the dielectric of the layer P in contact with the layer F The constant is 2.8 or less, and the dielectric loss tangent is 0.007 or less. A method for manufacturing a printed circuit board, which is to perform an etching treatment on the above-mentioned metal foil layer of a laminate according to any one of claims 1 to 12 to form a transmission circuit to obtain a printed circuit board. A printed substrate having a layer P of non-thermoplastic polyimide, a layer F of a tetrafluoroethylene polymer present on at least one side of the above-mentioned layer P, and a transmission circuit present on at least one side of the above-mentioned layer F, And the water absorption rate of the above layer P is less than 1.5%, and the absolute value of the linear expansion coefficient is 25 ppm/°C or less. An antenna formed by the printed circuit board as claimed in claim 14.