Resin composition, resin sheet, resin sheet with conductor layer, laminated substrate, and method for manufacturing resin sheet

Abstract

A resin composition 1s according to the present invention contains a liquid crystal polymer 1g and an inorganic filler 1h; the specific surface area of the inorganic filler 1h is 30 m2 / cm3 or less; the maximum diameter of the inorganic filler 1h is 100 µm or less; and the content ratio of the inorganic filler 1h is 0.1 vol% to 60 vol%.

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a resin sheet, a resin sheet with a conductor layer, a laminated substrate, and a method for producing a resin sheet. [Background technology]

[0002] Patent Document 1 discloses a resin composition characterized by containing (A) a synthetic resin having a melting temperature of 300°C or higher and (B) a plate-like inorganic filler having the following properties: aqueous dispersion pH: 5.5 to 8.0, eluted alkali amounts of Na: 30 ppm or less, K: 40 ppm or less, maximum diameter a: 50 μm or less, thickness b: 1.0 μm or less, and aspect ratio (a / b): 20 or more. Patent Document 1 discloses a liquid crystal polymer as a specific example of a synthetic resin having a melting temperature of 300°C or higher.

[0003] Patent Document 2 discloses a liquid crystalline polyester resin composition containing 10 to 80 parts by weight of (B) a plate-like filler relative to 100 parts by weight of (A) a liquid crystalline polyester resin, wherein the melting point of the liquid crystalline polyester resin in the liquid crystalline polyester resin composition is 300°C or higher and lower than 330°C, and the deflection temperature under load of a molded article obtained by molding the liquid crystalline polyester resin composition is 260°C or higher and lower than 285°C, as measured in accordance with ASTM D648.

[0004] Patent document 3 discloses a method for producing a liquid crystal polymer film containing a filler, which comprises the steps of obtaining a mixed powder of a liquid crystal polymer and a filler; forming a laminate having a layer of the mixed powder between two film-like heat-resistant substrates; and heat-compressing and molding the laminate between a pair of heated rolls. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO 01 / 40380 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-89154 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-111699 Summary of the Invention [Problem to be solved by the invention]

[0006] Due to their low dielectric constant, liquid crystal polymer sheets are known as components for improving the dielectric properties of laminated substrates used in various electronic devices in the high frequency range. On the other hand, in order to make the laminated substrates thinner, liquid crystal polymer sheets are required to be thinner.

[0007] In response to this, the present inventors have investigated forming a resin composition containing a liquid crystal polymer into a sheet by melt extrusion in order to obtain a thin liquid crystal polymer sheet.

[0008] However, the inventors have conducted research and found that when attempting to form the resin composition containing a liquid crystal polymer and a filler, as described in Patent Documents 1 and 2, into a sheet by melt extrusion, the presence of the filler reduces the melt tension of the resin composition, causing the resin composition to break during the forming process, and as a result, it is difficult to form the resin composition into a sheet.

[0009] Furthermore, the inventors have conducted studies and found that when a resin composition containing a liquid crystal polymer and a filler is molded into a sheet by the method described in Patent Document 3, it is possible to mold the resin composition into a sheet, but because there is a step in the process of kneading the molten liquid crystal polymer and the filler and then pulverizing them, foreign matter (e.g., metal) originating from the pulverizer or the like used in that step ends up being mixed into the resulting liquid crystal polymer sheet, resulting in so-called contamination.

[0010] The present invention has been made to solve the above problems, and has an object to provide a resin composition that can be formed into a sheet by melt extrusion. Another object of the present invention is to provide a resin sheet made of the resin composition, a resin sheet with a conductor layer having the resin sheet, and a laminate substrate having the resin sheet with a conductor layer. A further object of the present invention is to provide a method for producing a resin sheet that can form a resin composition into a sheet by melt extrusion without generating contamination. [Means for solving the problem]

[0011] The resin composition of the present invention contains a liquid crystal polymer and an inorganic filler, and the inorganic filler has a specific surface area of ​​30 m 2 / cm 3 The inorganic filler has a maximum diameter of 100 μm or less, and the inorganic filler content is 0.1 vol % or more and 60 vol % or less.

[0012] The resin sheet of the present invention is characterized by comprising the resin composition of the present invention.

[0013] The resin sheet with a conductor layer of the present invention is characterized by comprising the resin sheet of the present invention and a conductor layer adjacent to at least one main surface side of the resin sheet.

[0014] The laminated substrate of the present invention is characterized by comprising the resin sheet with a conductor layer of the present invention.

[0015] The method for producing a resin sheet of the present invention comprises using a liquid crystal polymer and a resin having a specific surface area of ​​30 m 2 / cm 3 and an inorganic filler having a maximum diameter of 100 μm or less, wherein the content of the inorganic filler is 0.1 vol% or more and 60 vol% or less; and a process of forming the resin composition into a sheet by a melt extrusion method. [Effects of the Invention]

[0016] According to the present invention, a resin composition that can be formed into a sheet by melt extrusion can be provided. Furthermore, according to the present invention, a resin sheet made of the resin composition, a resin sheet with a conductor layer that includes the resin sheet, and a laminated substrate that includes the resin sheet with a conductor layer can be provided. Furthermore, according to the present invention, a method for producing a resin sheet that can form a resin composition into a sheet by melt extrusion without generating contamination can be provided. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view showing an example of the resin sheet of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing an example of the resin sheet of the present invention, which is different from that shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view showing an example of the resin sheet of the present invention, which is different from the examples shown in FIGS. [Figure 4] FIG. 4 is a cross-sectional view showing an example of a resin sheet with a conductor layer according to the present invention. [Figure 5] FIG. 5 is a cross-sectional view showing an example of the laminated substrate of the present invention. [Figure 6] FIG. 6 is a cross-sectional view showing a process for producing a resin sheet with a conductor layer in an example of the method for producing a laminated substrate of the present invention. [Figure 7] FIG. 7 is a cross-sectional view showing a process for producing a resin sheet with a conductor layer in an example of the method for producing a laminated substrate of the present invention. [Figure 8] FIG. 8 is a cross-sectional view schematically illustrating a step of producing a resin sheet with a conductor layer in an example of a method for producing a laminated substrate of the present invention. [Figure 9] FIG. 9 is a cross-sectional view showing a process of forming a via hole in an example of the method for producing a laminated substrate of the present invention. [Figure 10] FIG. 10 is a cross-sectional view showing a process of forming via holes in an example of the method for producing a laminated substrate of the present invention. [Figure 11]FIG. 11 is a cross-sectional view showing a step of filling a conductive paste in an example of a method for producing a laminated substrate of the present invention. [Figure 12] FIG. 12 is a cross-sectional view showing a step of filling a conductive paste in an example of a method for producing a laminated substrate of the present invention. [Figure 13] FIG. 13 is a cross-sectional view showing a step of forming an interlayer connection conductor in an example of a method for producing a laminated substrate of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The resin composition of the present invention, the resin sheet of the present invention, the resin sheet with a conductor layer of the present invention, the laminated substrate of the present invention, and the method for producing the resin sheet of the present invention will be described below. Note that the present invention is not limited to the following configurations, and may be modified as appropriate within the scope of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0019] The resin composition of the present invention contains a liquid crystal polymer and an inorganic filler, and the inorganic filler has a specific surface area of ​​30 m 2 / cm 3 The inorganic filler has a maximum diameter of 100 μm or less, and the inorganic filler content is 0.1 vol % or more and 60 vol % or less.

[0020] The resin composition of the present invention contains a liquid crystal polymer and an inorganic filler.

[0021] The resin composition of the present invention contains a liquid crystal polymer, which allows the resin sheet made of the resin composition of the present invention to have a low dielectric constant, thereby improving the dielectric properties in the high frequency range of a laminate substrate having a resin sheet made of the resin composition of the present invention.

[0022] In the resin composition of the present invention, the liquid crystal polymer preferably contains a copolymer of p-hydroxybenzoic acid (HBA) and 6-hydroxy-2-naphthoic acid (HNA).

[0023] Copolymers of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid are generally referred to as type II fully aromatic polyesters (also called type 1.5 fully aromatic polyesters). Type II fully aromatic polyesters are less susceptible to hydrolysis than type III partially aromatic polyesters, making them preferable as materials for laminate substrates. Furthermore, type II fully aromatic polyesters have a small dielectric loss tangent due to the naphthalene ring, which contributes to reducing electrical energy loss in the resin sheets in laminate substrates.

[0024] In the resin composition of the present invention, the liquid crystal polymer may further contain a type I wholly aromatic polyester in addition to the type II wholly aromatic polyester, or may further contain a type III partially aromatic polyester, or may further contain a type I wholly aromatic polyester and a type III partially aromatic polyester.

[0025] The structure (type) of each monomer constituting the liquid crystal polymer can be analyzed by reactive pyrolysis gas chromatography mass spectrometry (reactive pyrolysis GC-MS method).

[0026] In the resin composition of the present invention, when the liquid crystal polymer contains a copolymer of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, the molar ratio of p-hydroxybenzoic acid to 6-hydroxy-2-naphthoic acid is preferably 0.20 or more and 5 or less.

[0027] In the liquid crystal polymer, if the molar ratio of p-hydroxybenzoic acid to 6-hydroxy-2-naphthoic acid is lower than 0.20 or higher than 5, the melting point of the resin composition may become higher than the preferred range described below.

[0028] In the resin composition of the present invention, when the liquid crystal polymer contains a copolymer of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, the liquid crystal polymer preferably contains 10 mol % or more of p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, respectively, when the total amount of monomers is 100 mol %.

[0029] If the content of each of the p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid monomers in the liquid crystal polymer is less than 10 mol%, it may be difficult to achieve the liquid crystallinity of the liquid crystal polymer, the melting point of the resin composition falling within the preferred range described below, and the dielectric tangent of the liquid crystal polymer becoming small.

[0030] The ratio and content of each monomer constituting the liquid crystal polymer can be analyzed by reactive pyrolysis gas chromatography mass spectrometry.

[0031] The resin composition of the present invention contains a liquid crystal polymer as a resin component. The resin component may contain components other than the liquid crystal polymer as long as it contains the liquid crystal polymer as a main component.

[0032] As used herein, the term "major component" means the component with the highest weight percentage.

[0033] The resin composition of the present invention contains an inorganic filler, which can impart the following various properties to a resin sheet made of the resin composition of the present invention.

[0034] The resin composition of the present invention may contain an inorganic filler to impart heat dissipation properties to the resin sheet. When the resin sheet has heat dissipation properties, heat generated by the internal resistance of the components is easily dissipated to the outside, which tends to improve the safety and reliability of the laminate substrate having the resin sheet, and ultimately of the electronic device using the laminate substrate.

[0035] Examples of inorganic fillers that can impart heat dissipation properties include boron nitride, aluminum nitride, silicon carbide, alumina, talc, metals, etc. Among these, boron nitride is preferred as an inorganic filler that can impart heat dissipation properties because it is less likely to decompose the liquid crystal polymer.

[0036] The resin composition of the present invention may contain an inorganic filler to impart a high dielectric constant to the resin sheet. If the resin sheet has a high dielectric constant, when a laminate substrate having the resin sheet is used in an antenna component, the radio waves used by the antenna component tend to have a shorter wavelength, making it easier to miniaturize the antenna component.

[0037] Examples of inorganic fillers that can impart a high dielectric constant include titanium oxide, barium titanate, calcium titanate, and zirconate titanate. lead Among these, titanium oxide is preferred as an inorganic filler that can impart a high dielectric constant because it is less likely to decompose the liquid crystal polymer.

[0038] The resin composition of the present invention may contain an inorganic filler to impart magnetism to the resin sheet. When the resin sheet has magnetism, the resin sheet can shield external electromagnetic waves (absorb noise) in a laminate substrate having the resin sheet.

[0039] Examples of inorganic fillers that can impart magnetism include ferrite, metals, etc. Among these, ferrite is preferred as the inorganic filler that can impart magnetism because its physical properties are less likely to change due to oxidation.

[0040] The resin composition of the present invention may contain an inorganic filler to impart flame retardancy to the resin sheet. When the resin sheet has flame retardancy, the safety of a laminate substrate having the resin sheet, and therefore of an electronic device using the laminate substrate, is likely to be improved.

[0041] Examples of inorganic fillers that can impart flame retardancy include magnesium hydroxide, antimony oxide, aluminum hydroxide, zinc borate, molybdic acid compounds, tin oxide compounds, phosphorus compounds, iron oxide, cuprous oxide, silica, etc. Among these, magnesium hydroxide is preferred because of its significant effect of imparting flame retardancy.

[0042] The resin composition of the present invention may contain a lightweight inorganic filler. When the inorganic filler in the resin composition is lightweight, the resin sheet is also lightweight, and therefore, when a laminate substrate having the resin sheet is used in an automobile part, the fuel efficiency of the automobile is likely to be improved.

[0043] Examples of inorganic fillers that can reduce weight include inorganic fillers having a hollow structure, such as hollow silica and hollow glass. Among these, hollow silica is preferred as an inorganic filler that can reduce weight because it is less likely to decompose the liquid crystal polymer.

[0044] In the resin composition of the present invention, the inorganic filler may be surface-treated. That is, in the resin composition of the present invention, a surface-treated layer may be provided on the surface of the inorganic filler. This tends to improve the dispersibility of the inorganic filler in the resin composition, so that the physical properties of the resin composition derived from the inorganic filler are less likely to vary depending on the position in the resin composition.

[0045] Examples of materials constituting the surface treatment layer include silane coupling agents, titanate coupling agents, phosphate esters, and fatty acids (such as stearic acid and oleic acid).

[0046] In the resin composition of the present invention, the specific surface area of ​​the inorganic filler is 30 m 2 / cm 3 The following is the result.

[0047] In the resin composition of the present invention, the specific surface area of ​​the inorganic filler is 30 m 2 / cm 3 The specific surface area of ​​the inorganic filler is 30m or less.2 / cm 3 In comparison with a resin composition having a specific surface area of ​​30 m or more, the intermolecular interactions and entanglements between the liquid crystal polymers are more likely to remain, and therefore the melt tension of the resin composition is less likely to decrease. 2 / cm 3 or less, the resin composition of the present invention can easily maintain a high melt tension. Therefore, when the resin composition of the present invention is molded into a sheet by melt extrusion, the resin composition can withstand the tensile stress during the molding process. Therefore, the resin composition of the present invention is less likely to break during the molding process of molding into a sheet by melt extrusion.

[0048] In the resin composition of the present invention, the specific surface area of ​​the inorganic filler is 20 m 2 / cm 3 It is preferable that:

[0049] In the resin composition of the present invention, the specific surface area of ​​the inorganic filler is 20 m 2 / cm 3 When the above condition is satisfied, the interface between the liquid crystal polymer and the inorganic filler is likely to be reduced, and therefore the amount of moisture trapped at the interface between the liquid crystal polymer and the inorganic filler is reduced, and as a result, the water absorption rate of the resin sheet made of the resin composition is likely to be reduced.

[0050] In the resin composition of the present invention, the specific surface area of ​​the inorganic filler is 0.1 m 2 / cm 3 It is preferable that this is equal to or greater than this.

[0051] In the resin composition of the present invention, the specific surface area of ​​the inorganic filler is 0.1 m 2 / cm 3 If it is smaller than this, it may be difficult to make the maximum diameter of the inorganic filler, which will be described later, 100 μm or less.

[0052] The method for determining the specific surface area of ​​an inorganic filler from the state of a resin composition is as follows. First, the inorganic filler is removed from the resin composition and then degassed. The specific surface area of ​​the inorganic filler is then measured using the BET single-point method. Specifically, the specific surface area of ​​the inorganic filler is calculated from the amount of nitrogen gas adsorbed on the surface of an inorganic filler weighed out at approximately 0.1 g or more and 1.0 g or less. When measuring the specific surface area of ​​an inorganic filler, a specific surface area measuring device such as the fully automatic specific surface area measuring device "Macsorb (registered trademark)" manufactured by Mountech Co., Ltd. is used. When determining the specific surface area of ​​an inorganic filler from the state of a resin sheet or laminate substrate, as described below, the inorganic filler is removed from the target resin sheet and the specific surface area of ​​the inorganic filler is determined using the method described above.

[0053] In the resin composition of the present invention, the maximum diameter of the inorganic filler is 100 μm or less.

[0054] In the resin composition of the present invention, the maximum diameter of the inorganic filler is as small as 100 μm or less. Therefore, when the resin composition is molded into a sheet by melt extrusion, the resulting resin sheet is less likely to develop holes and therefore less likely to break, compared to a resin composition in which the maximum diameter of the inorganic filler is greater than 100 μm.

[0055] In the resin composition of the present invention, the maximum diameter of the inorganic filler is preferably 1 μm or more.

[0056] In the resin composition of the present invention, if the maximum diameter of the inorganic filler is less than 1 μm, the specific surface area of ​​the inorganic filler described above will be 30 m 2 / cm 3 It can be difficult to:

[0057] The method for determining the maximum diameter of the inorganic filler from the state of the resin composition is as follows. First, the inorganic filler is extracted from the resin composition and then ultrasonically dispersed in ethanol. Then, the particle size distribution of the inorganic filler is measured by a laser diffraction / scattering method. At this time, the particle size of the inorganic filler is measured as the equivalent circle diameter. When measuring the particle size distribution of the inorganic filler, a laser diffraction / scattering particle size distribution analyzer such as the laser diffraction / scattering particle size distribution analyzer "LA-960" manufactured by Horiba, Ltd. is used. The maximum particle size in the obtained particle size distribution of the inorganic filler is then determined as the maximum diameter of the inorganic filler. Note that when determining the maximum diameter of the inorganic filler from the state of a resin sheet or laminated substrate described below, the inorganic filler is extracted from the target resin sheet and the maximum diameter of the inorganic filler is determined by the above-mentioned method.

[0058] In the resin composition of the present invention, the content of the inorganic filler is 0.1 vol % or more and 60 vol % or less.

[0059] In the resin composition of the present invention, the content of the inorganic filler is 0.1 vol% or more and 60 vol% or less, so that the melt tension of the resin composition is less likely to decrease. In other words, in the resin composition of the present invention, the content of the inorganic filler is 0.1 vol% or more and 60 vol% or less, so that a high melt tension is more likely to be maintained and the properties imparted by the inorganic filler described above are more likely to be exhibited. Therefore, when the resin composition of the present invention is molded into a sheet by melt extrusion, the resin composition can withstand the tensile stress during the molding process. Therefore, the resin composition of the present invention is less likely to break during the molding process of molding into a sheet by melt extrusion.

[0060] In the resin composition of the present invention, if the content of the inorganic filler is lower than 0.1 vol%, the above-mentioned properties imparted by the inorganic filler are difficult to exhibit. In the resin composition of the present invention, even if the content of the inorganic filler is as low as 0.1 vol%, for example, flame retardancy can be imparted to the resin sheet.

[0061] In the resin composition of the present invention, if the content of inorganic filler is higher than 60 vol%, the melt tension of the resin composition is likely to decrease, and the resin composition is therefore likely to break during the molding process of molding it into a sheet by melt extrusion.

[0062] The method for determining the inorganic filler content from the state of the resin composition is as follows. First, using a simultaneous thermogravimetry and differential thermal analysis (TG-DTA) device, the resin composition is heated to, for example, 600°C and then left at 600°C for 45 minutes to completely thermally decompose the resin components (liquid crystal polymer, etc.) in the resin composition. Then, the content of the inorganic filler in the resin composition is calculated from the volume (weight) of the inorganic filler remaining after the resin components have been removed. Note that when determining the inorganic filler content from the state of a resin sheet or laminate substrate, which will be described later, the measurement target in the above-mentioned method can be changed from the resin composition to a resin sheet.

[0063] From the above, according to the resin composition of the present invention, even in a composite state containing a liquid crystal polymer and an inorganic filler, the specific surface area of ​​the inorganic filler is 30 m 2 / cm 3 By satisfying all of the following requirements: the thickness of the inorganic filler is 100 μm or less, the maximum diameter of the inorganic filler is 100 μm or less, and the content of the inorganic filler is 0.1 vol% or more and 60 vol% or less, a resin composition that can be molded into a sheet by melt extrusion can be realized.

[0064] In the resin composition of the present invention, the inorganic filler is preferably plate-shaped.

[0065] Generally, in a composite resin composition containing a liquid crystal polymer and an inorganic filler, the presence of the inorganic filler tends to reduce the orientation of the liquid crystal polymer, so that when the resin composition is molded into a sheet, the tensile elongation at break of the resin sheet tends to decrease. On the other hand, when the inorganic filler is plate-shaped, the orientation of the liquid crystal polymer in the resin composition is less likely to decrease, so that when the resin composition is molded into a sheet, the tensile elongation at break of the resin sheet is less likely to decrease.

[0066] In this specification, the term "plate-like" refers to a shape that extends in an in-plane direction perpendicular to the thickness direction, such as boron nitride, talc, etc.

[0067] In the resin composition of the present invention, the inorganic filler may have a shape other than a plate shape, such as a spherical shape.

[0068] In the resin composition of the present invention, the average particle size of the inorganic filler is preferably 0.1 μm or more and 30 μm or less.

[0069] The method for determining the average particle size of the inorganic filler from the state of the resin composition is as follows. First, the particle size distribution of the inorganic filler obtained when determining the maximum diameter of the inorganic filler is converted into a cumulative probability, thereby determining the volume-based cumulative particle size distribution of the inorganic filler. Then, the median diameter D 50 (particle size at which the cumulative probability is 50%) and calculate the median diameter D 50 is defined as the average particle size of the inorganic filler. When determining the average particle size of the inorganic filler from the state of a resin sheet or a laminated substrate described later, the inorganic filler is removed from the target resin sheet and then the average particle size of the inorganic filler is determined by the above-mentioned method.

[0070] In the resin composition of the present invention, the thickness of the inorganic filler is preferably 1 nm or more and 1000 nm or less.

[0071] The method for determining the thickness of the inorganic filler from the state of the resin composition is as follows. First, the inorganic filler is removed from the resin composition, and then an image of the inorganic filler is taken with a scanning electron microscope (SEM). Next, the obtained image of the inorganic filler is subjected to image analysis using analysis software or the like to measure the dimension of the inorganic filler in the short side direction (the direction with the shortest dimension). Then, the dimension measurement in the short side direction is performed on 100 inorganic fillers, and the average value of the obtained 100 measurements is determined as the thickness of the inorganic filler. Note that when determining the thickness of the inorganic filler from the state of a resin sheet or laminated substrate described below, the inorganic filler is removed from the target resin sheet, and the thickness of the inorganic filler is determined by the method described above.

[0072] In the resin composition of the present invention, the aspect ratio of the inorganic filler is preferably 2 or more and 100 or less.

[0073] The method for determining the aspect ratio of an inorganic filler from the state of a resin composition is as follows. First, the inorganic filler is removed from the resin composition, and an image of the inorganic filler is taken with a scanning electron microscope. Next, the obtained image of the inorganic filler is subjected to image analysis using analysis software or the like to measure the dimension of the inorganic filler in the short side direction and the dimension of the inorganic filler in the long side direction (the direction in which the dimension is longest). The above-mentioned dimension measurements in the short side direction and the long side direction are then performed on 100 inorganic fillers, and the aspect ratio of the inorganic filler is determined as B / A, where A is the average value of the 100 measured values ​​obtained as the dimension in the short side direction and B is the average value of the 100 measured values ​​obtained as the dimension in the long side direction. Note that when determining the aspect ratio of an inorganic filler from the state of a resin sheet or laminate substrate described below, the inorganic filler is removed from the target resin sheet, and the aspect ratio of the inorganic filler is determined by the above-mentioned method.

[0074] In the resin composition of the present invention, it is preferable that the inorganic filler has an average particle size of 0.1 μm or more and 30 μm or less, a thickness of 1 nm or more and 1000 nm or less, and an aspect ratio of 2 or more and 100 or less.

[0075] In the resin composition of the present invention, the inorganic filler has an average particle size of 0.1 μm or more and 30 μm or less, a thickness of 1 nm or more and 1000 nm or less, and an aspect ratio of 2 or more and 100 or less. This makes it easier for the liquid crystal polymer to be captured by the inorganic filler. Therefore, when the resin composition is molded into a sheet to form a resin sheet, the resin sheet tends to have a small in-plane linear expansion coefficient. If the resin sheet has a small in-plane linear expansion coefficient, when the resin sheet is used to form a resin sheet or laminate substrate with a conductor layer, as described below, the in-plane linear expansion coefficient of the resin sheet can be made closer to the in-plane linear expansion coefficient of the conductor layer (e.g., copper foil). As a result, the resin sheet or laminate substrate with a conductor layer is less likely to warp due to the difference in the in-plane linear expansion coefficients of the resin sheet and the conductor layer.

[0076] In the resin composition of the present invention, the melt tension at a temperature 20° C. higher than the melting point of the resin composition is preferably 1.0 mN or more.

[0077] The resin composition of the present invention has a melt tension of 1.0 mN or more at a temperature 20° C. higher than the melting point of the resin composition, which makes it easy to form into a sheet by melt extrusion.

[0078] In the resin composition of the present invention, the melt tension at a temperature 20° C. higher than the melting point of the resin composition is preferably 7.0 mN or less.

[0079] In the resin composition of the present invention, if the melt tension at a temperature 20°C higher than the melting point of the resin composition is higher than 7.0 mN, it is necessary to increase the tension when taking up the molded product in the process of molding the resin composition into a sheet by melt extrusion. If the tension when taking up the molded product is increased in this way, it becomes difficult to maintain a constant speed when taking up the molded product, and the thickness of the obtained resin sheet may vary.

[0080] The melting point of a resin composition is determined as follows. First, the resin composition is heated using a differential scanning calorimeter to completely melt it. As a differential scanning calorimeter, for example, a differential scanning calorimeter "DSC7000X" manufactured by Hitachi High-Tech Science Corporation is used. Next, the resulting molten material is cooled and then heated again. The temperature corresponding to the endothermic peak observed during this heating process is determined as the melting point of the resin composition. If an endothermic peak is difficult to observe using the above-mentioned method, the melting point of the resin composition is determined by texture observation under crossed Nicols conditions using a polarizing microscope. When determining the melting point of a resin composition from the state of a resin sheet or laminate substrate described below, the measurement target in the above-mentioned method can be changed from the resin composition to a resin sheet.

[0081] The melt tension of a resin composition at a temperature 20°C higher than the melting point of the resin composition is measured using a melt tension measuring device at a temperature 20°C higher than the melting point of the resin composition determined by the above-mentioned method. As a melt tension measuring device, for example, a Capilograph (registered trademark) "F-1" manufactured by Toyo Seiki Seisaku-sho, Ltd. can be used. Note that when determining the melt tension of a resin composition at a temperature 20°C higher than the melting point of the resin composition from the state of a resin sheet or laminate substrate described below, the measurement target in the above-mentioned method can be changed from the resin composition to a resin sheet.

[0082] The melting point of the resin composition of the present invention is preferably 275°C or higher and 330°C or lower.

[0083] If the melting point of the resin composition of the present invention is lower than 275°C, the heat resistance of the resin sheet may be insufficient when a laminate substrate having a resin sheet made of the resin composition of the present invention is incorporated into an electronic device by reflow soldering.

[0084] If the melting point of the resin composition of the present invention is higher than 330°C, a higher processing temperature is required when molding the resin composition of the present invention into a sheet, which may accelerate the deterioration of the liquid crystal polymer contained in the resin composition of the present invention.

[0085] The resin sheet of the present invention is characterized by comprising the resin composition of the present invention.

[0086] In this specification, the term "sheet" is synonymous with "film," and the two are not distinguished by thickness.

[0087] FIG. 1 is a cross-sectional view showing an example of the resin sheet of the present invention.

[0088] A resin sheet 1 shown in FIG. 1 has a first main surface 1a and a second main surface 1b that face each other in the thickness direction.

[0089] The thickness of the resin sheet 1 is preferably 10 μm or more and 250 μm or less.

[0090] The resin sheet 1 is made of a resin composition 1s containing a liquid crystal polymer 1g and an inorganic filler 1h.

[0091] Resin composition 1s corresponds to the resin composition of the present invention.

[0092] The characteristics of the liquid crystal polymer 1g are the same as those of the liquid crystal polymer contained in the resin composition of the present invention described above.

[0093] The inorganic filler 1h has the same characteristics as the inorganic filler contained in the resin composition of the present invention described above. That is, in the resin sheet 1, the inorganic filler 1h has a specific surface area of ​​30 m 2 / cm 3The essential characteristics of the inorganic filler 1h are that the inorganic filler 1h has a maximum diameter of 100 μm or less, and that the content of the inorganic filler 1h is 0.1 vol % or more and 60 vol % or less.

[0094] 1, the inorganic filler 1h is preferably plate-shaped. In this case, even if the resin sheet 1 contains the inorganic filler 1h, the orientation of the liquid crystal polymer 1g is less likely to decrease, and therefore the tensile elongation at break of the resin sheet 1 is less likely to decrease.

[0095] 1, when the inorganic filler 1h is plate-shaped, the inorganic filler 1h is preferably oriented in the in-plane direction of the resin sheet 1. In this case, the linear expansion coefficient of the resin sheet 1 in the in-plane direction tends to be small, so that when the resin sheet 1 is used to form a resin sheet or laminate substrate with a conductor layer, which will be described later, the linear expansion coefficient of the resin sheet 1 in the in-plane direction can be made closer to the linear expansion coefficient of the conductor layer (e.g., copper foil) in the in-plane direction. As a result, the resin sheet or laminate substrate with a conductor layer is less likely to warp due to the difference in the linear expansion coefficients in the in-plane direction between the resin sheet 1 and the conductor layer.

[0096] The state in which the inorganic filler is oriented in the in-plane direction of the resin sheet means a state in which, when the resin sheet is viewed as a whole, the orientation direction of the inorganic filler can be said to be substantially parallel to the in-plane direction of the resin sheet, and the orientation direction of the inorganic filler does not need to be strictly parallel to the in-plane direction of the resin sheet.

[0097] 1, it is preferable that the inorganic filler 1h is not aggregated. In this case, the physical properties of the resin sheet 1 derived from the inorganic filler 1h are less likely to vary depending on the position within the resin sheet 1.

[0098] 1, it is preferable that the inorganic filler 1h is present in a small amount in the region near the first main surface 1a of the resin sheet 1, and it is more preferable that the inorganic filler 1h is not present in the region near the first main surface 1a of the resin sheet 1. In this case, even if a conductor layer (e.g., copper foil) is adjacent to the first main surface 1a side of the resin sheet 1 in a resin sheet or laminate substrate with a conductor layer described below, a decrease in the adhesive strength between the resin sheet 1 and the conductor layer caused by the inorganic filler 1h is suppressed.

[0099] As shown in Figure 1, it is preferable that the inorganic filler 1h is small not only in the area near the first main surface 1a of the resin sheet 1 but also in the area near the second main surface 1b of the resin sheet 1, and it is more preferable that it is not present in the area near the second main surface 1b of the resin sheet 1.

[0100] In other words, it is preferable that the inorganic filler 1h is present in small amounts in the area near at least one of the first main surface 1a and the second main surface 1b of the resin sheet 1, and it is even more preferable that it is not present in the area near at least one of the first main surface 1a and the second main surface 1b of the resin sheet 1.

[0101] In this specification, the region near the first main surface of the resin sheet refers to the region between the first main surface and the first vicinity position, where the position that is closer to the first main surface is either a position that is 1 / 5 of the thickness of the resin sheet in the thickness direction from the first main surface or a position that is 5 μm away from the first main surface in the thickness direction from the first main surface. The region near the second main surface of the resin sheet refers to the region between the second main surface and the second vicinity position, where the position that is closer to the second main surface is either a position that is 1 / 5 of the thickness of the resin sheet in the thickness direction from the second main surface or a position that is 5 μm away from the second main surface in the thickness direction from the second main surface.

[0102] FIG. 2 is a cross-sectional view showing an example of the resin sheet of the present invention, which is different from that shown in FIG.

[0103] The resin sheet 1' shown in FIG. 2 is made of a resin composition 1s' containing a liquid crystal polymer 1g and an inorganic filler 1h.

[0104] In the resin sheet 1', the inorganic filler 1h has been subjected to a surface treatment. More specifically, in the resin sheet 1', a surface treatment layer 3 is provided on the surface of the inorganic filler 1h.

[0105] FIG. 3 is a cross-sectional view showing an example of the resin sheet of the present invention, which is different from the examples shown in FIGS.

[0106] The resin sheet 1'' shown in FIG. 3 is made of a resin composition 1s'' containing a liquid crystal polymer 1g and an inorganic filler 1h''.

[0107] In the resin sheet 1'', the inorganic filler 1h'' is spherical.

[0108] The method for producing a resin sheet of the present invention comprises using a liquid crystal polymer and a resin having a specific surface area of ​​30 m 2 / cm 3 and an inorganic filler having a maximum diameter of 100 μm or less, wherein the content of the inorganic filler is 0.1 vol% or more and 60 vol% or less; and a process of forming the resin composition into a sheet by a melt extrusion method.

[0109] <Step of Preparing Resin Composition> Liquid crystal polymer and a specific surface area of ​​30m 2 / cm 3 The resin composition of the present invention contains an inorganic filler having a maximum diameter of 100 μm or less, and the inorganic filler content is 0.1 vol% or more and 60 vol% or less. In this case, the liquid crystal polymer and the inorganic filler may be melt-kneaded in a twin-screw extruder, for example, to prepare a molten resin composition.

[0110] <Step of molding the resin composition into a sheet> The resin composition is formed into a sheet by melt extrusion. In this case, for example, the resin composition in a molten state may be extruded from a T-die and then cooled to form the resin composition into a sheet.

[0111] In this manner, the resin sheet of the present invention is produced.

[0112] According to the method for producing a resin sheet of the present invention, there is no need for a process of kneading a molten liquid crystal polymer and an inorganic filler and then pulverizing them, as in the method described in Patent Document 3. Therefore, it is possible to form a resin composition into a sheet by melt extrusion without generating contamination.

[0113] The resin composition used in the above manufacturing method is a liquid crystal polymer and a polymer having a specific surface area of ​​30 m 2 / cm 3 and an inorganic filler having a maximum diameter of 100 μm or less, and a content of the inorganic filler of 0.1 vol% or more and 60 vol% or less, i.e., the resin composition of the present invention. Therefore, according to the above-mentioned manufacturing method, a resin sheet molded into a sheet shape by melt extrusion can be manufactured.

[0114] The resin sheet with a conductor layer of the present invention is characterized by comprising the resin sheet of the present invention and a conductor layer adjacent to at least one main surface side of the resin sheet.

[0115] FIG. 4 is a cross-sectional view showing an example of a resin sheet with a conductor layer according to the present invention.

[0116] A resin sheet 10 with a conductor layer shown in FIG. 4 has a resin sheet 1 and a conductor layer 2 in the stacking direction.

[0117] In this specification, the lamination direction corresponds to the direction along the thickness direction of the resin sheets that constitute the resin sheet with a conductor layer.

[0118] The conductor layer 2 is adjacent to at least one main surface side of the resin sheet 1, here, the first main surface 1a side.

[0119] The conductor layer 2 may be in the form of a surface that spreads over a whole surface, or may be in the form of a pattern that is patterned into wiring or the like.

[0120] Examples of materials that can be used to form the conductor layer 2 include copper, silver, aluminum, stainless steel, nickel, gold, and alloys containing at least one of these metals.

[0121] The conductor layer 2 is made of, for example, a metal foil, and is preferably made of copper foil among other metal foils. In this case, metals other than copper may be present on the surface of the copper foil.

[0122] The thickness of the conductor layer 2 is preferably 1 μm or more and 35 μm or less, and more preferably 6 μm or more and 18 μm or less.

[0123] The resin sheet 10 with a conductor layer may further have, in addition to the conductor layer 2, another conductor layer adjacent to the resin sheet 1 on the second main surface 1b side.

[0124] The resin sheet 10 with a conductor layer is produced, for example, by pressure-bonding the conductor layer 2 to the first main surface 1a of the resin sheet 1. After being pressure-bonded to the first main surface 1a of the resin sheet 1, the conductor layer 2 may be etched to have a pattern shape.

[0125] The resin sheet 10 with a conductor layer may be produced by pressure bonding a pre-patterned conductor layer 2 to the first main surface 1a of the resin sheet 1.

[0126] The laminated substrate of the present invention is characterized by comprising the resin sheet with a conductor layer of the present invention.

[0127] FIG. 5 is a cross-sectional view showing an example of the laminated substrate of the present invention.

[0128] 5 includes a resin sheet 10A with a conductor layer, a resin sheet 10B with a conductor layer, and a resin sheet 10C in this order in the stacking direction. That is, in the laminated substrate 50, the resin sheet 10A with a conductor layer, the resin sheet 10B with a conductor layer, and the resin sheet 10C with a conductor layer are stacked in this order in the stacking direction.

[0129] The resin sheet 10A with a conductor layer has a resin sheet 1A and a conductor layer 2A.

[0130] The resin sheet 1A has a first main surface 1Aa and a second main surface 1Ab that face each other in the thickness direction.

[0131] The resin sheet 1A is made of a resin composition 1As containing a liquid crystal polymer 1Ag and an inorganic filler 1Ah.

[0132] The conductor layer 2A is adjacent to the first main surface 1Aa side of the resin sheet 1A. The conductor layer 2A is also adjacent to the second main surface 1Bb side of the resin sheet 1B, which will be described later.

[0133] The resin sheet 10B with a conductor layer has a resin sheet 1B, a conductor layer 2B, a conductor layer 2B', and a conductor layer 2B''.

[0134] The resin sheet 1B has a first main surface 1Ba and a second main surface 1Bb that face each other in the thickness direction.

[0135] The resin sheet 1B is made of a resin composition 1Bs containing a liquid crystal polymer 1Bg and an inorganic filler 1Bh.

[0136] The conductor layer 2B, the conductor layer 2B', and the conductor layer 2B'' are adjacent to the first main surface 1Ba side of the resin sheet 1B. In addition, the conductor layer 2B, the conductor layer 2B', and the conductor layer 2B'' are also adjacent to the second main surface 1Cb side of the resin sheet 1C described later.

[0137] The resin sheet 10C with a conductor layer has a resin sheet 1C and a conductor layer 2C.

[0138] The resin sheet 1C has a first main surface 1Ca and a second main surface 1Cb that face each other in the thickness direction.

[0139] The resin sheet 1C is made of a resin composition 1Cs containing a liquid crystal polymer 1Cg and an inorganic filler 1Ch.

[0140] The conductor layer 2C is adjacent to the first main surface 1Ca side of the resin sheet 1C.

[0141] The conductor layer 2B is preferably provided across the interface between the resin sheet 1B and the resin sheet 1C, as shown in Fig. 5. This allows the interface between the conductor layer 2B and the resin sheet 1B and the interface between the conductor layer 2B and the resin sheet 1C to be shifted in the stacking direction from the interface between the resin sheet 1B and the resin sheet 1C, thereby suppressing peeling at the interface between the conductor layer 2B and the resin sheet 1B and the interface between the conductor layer 2B and the resin sheet 1C.

[0142] Like the conductor layer 2B, the conductor layer 2B' and the conductor layer 2B'' are preferably provided across the interface between the resin sheet 1B and the resin sheet 1C.

[0143] 5 shows the interface between resin sheet 1B and resin sheet 1C, but in reality, this interface does not have to be clearly visible. When the interface between resin sheet 1B and resin sheet 1C is not clearly visible, in a cross section along the stacking direction as shown in FIG. 5, a plane that passes through the center in the stacking direction of the cross section of conductor layer 2B and extends along an in-plane direction perpendicular to the stacking direction is considered to be the interface between resin sheet 1B and resin sheet 1C.

[0144] In at least one resin sheet (resin composition) among the resin sheet 1A (resin composition 1As), the resin sheet 1B (resin composition 1Bs), and the resin sheet 1C (resin composition 1Cs), the specific surface area of ​​the inorganic filler is 30 m 2 / cm 3 The inorganic filler has a maximum diameter of 100 μm or less, and the inorganic filler content is 0.1 vol% or more and 60 vol% or less.

[0145] That is, the laminated substrate 50 has an inorganic filler with a specific surface area of ​​30 m 2 / cm 3The maximum diameter of the inorganic filler is 100 μm or less, and the content of the inorganic filler is 0.1 vol% or more and 60 vol% or less. If there is at least one resin sheet that satisfies all of these conditions, the specific surface area of ​​the inorganic filler is 30 m 2 / cm 3 The resin sheet may have a thickness of 100 μm or less, a maximum diameter of the inorganic filler of 100 μm or less, and a content of the inorganic filler of 0.1 vol % or more and 60 vol % or less.

[0146] In all of the resin sheets 1A, 1B, and 1C, the specific surface area of ​​the inorganic filler is 30 m 2 / cm 3 It is preferable that the inorganic filler has a maximum diameter of 100 μm or less, and the inorganic filler content is 0.1 vol % or more and 60 vol % or less.

[0147] The thicknesses of the resin sheets 1A, 1B, and 1C may be the same as one another, may be different from one another, or may be partially different as shown in FIG.

[0148] The constituent materials of conductor layer 2A, conductor layer 2B, conductor layer 2B', conductor layer 2B'', and conductor layer 2C are similar to the constituent materials of conductor layer 2, and include, for example, copper, silver, aluminum, stainless steel, nickel, gold, and alloys containing at least one of these metals.

[0149] Like the conductor layer 2, the conductor layer 2A, the conductor layer 2B, the conductor layer 2B', the conductor layer 2B'', and the conductor layer 2C are made of, for example, a metal foil, and among metal foils, it is preferable that they are made of copper foil. In this case, a metal other than copper may be present on the surface of the copper foil.

[0150] The constituent materials of the conductor layer 2A, the conductor layer 2B, the conductor layer 2B', the conductor layer 2B'', and the conductor layer 2C are preferably the same as one another, but may be different from one another or may be partially different from one another.

[0151] The thicknesses of the conductor layer 2A, the conductor layer 2B, the conductor layer 2B', the conductor layer 2B'', and the conductor layer 2C may be the same as each other as shown in FIG. 5, may be different from each other, or may be partially different.

[0152] The laminated substrate 50 has three resin sheets with conductor layers in the lamination direction, but may have only one, two, or four or more.

[0153] As shown in FIG. 5, it is preferable that the laminated substrate 50 further has an interlayer connection conductor that penetrates the resin sheet in the stacking direction but does not penetrate the conductor layer in the stacking direction, and is provided so as to be connected to the conductor layer.

[0154] The laminated substrate 50 shown in FIG. 5 further includes an interlayer connection conductor 20A, an interlayer connection conductor 20B, an interlayer connection conductor 20C, and an interlayer connection conductor 20D.

[0155] The interlayer connection conductor 20A is provided so as to penetrate the resin sheet 1B in the stacking direction but not through the conductor layer 2B' in the stacking direction, and to be connected to the conductor layer 2B'. More specifically, the interlayer connection conductor 20A penetrates the resin sheet 1B in the stacking direction and is connected to the conductor layer 2B' on the first main surface 1Ba side of the resin sheet 1B. The interlayer connection conductor 20A is also connected to the conductor layer 2A on the second main surface 1Bb side of the resin sheet 1B. In other words, the conductor layer 2A and the conductor layer 2B' are electrically connected via the interlayer connection conductor 20A.

[0156] The interlayer connection conductor 20B is provided at a position spaced apart from the interlayer connection conductor 20A so as to penetrate the resin sheet 1B in the stacking direction but not through the conductor layer 2B'' in the stacking direction and be connected to the conductor layer 2B''. More specifically, the interlayer connection conductor 20B is provided at a position spaced apart from the interlayer connection conductor 20A so as to penetrate the resin sheet 1B in the stacking direction and be connected to the conductor layer 2B'' on the first main surface 1Ba side of the resin sheet 1B. Furthermore, the interlayer connection conductor 20B is connected to the conductor layer 2A on the second main surface 1Bb side of the resin sheet 1B at a position spaced apart from the interlayer connection conductor 20A. In other words, the conductor layer 2A and the conductor layer 2B'' are electrically connected via the interlayer connection conductor 20B.

[0157] The interlayer connection conductor 20C is provided so as to penetrate the resin sheet 1C in the stacking direction but not the conductor layer 2C in the stacking direction so as to be connected to the conductor layer 2C. More specifically, the interlayer connection conductor 20C penetrates the resin sheet 1C in the stacking direction and is connected to the conductor layer 2C on the first main surface 1Ca side of the resin sheet 1C. The interlayer connection conductor 20C is also connected to the conductor layer 2B' on the second main surface 1Cb side of the resin sheet 1C. In other words, the conductor layer 2B' and the conductor layer 2C are electrically connected via the interlayer connection conductor 20C.

[0158] The interlayer connection conductor 20D is provided at a position spaced apart from the interlayer connection conductor 20C, penetrating the resin sheet 1C in the stacking direction but not penetrating the conductor layer 2C in the stacking direction, so as to be connected to the conductor layer 2C. More specifically, the interlayer connection conductor 20D is connected to the conductor layer 2C on the first main surface 1Ca side of the resin sheet 1C, while penetrating the resin sheet 1C in the stacking direction, at a position spaced apart from the interlayer connection conductor 20C. Furthermore, the interlayer connection conductor 20D is connected to the conductor layer 2B" on the second main surface 1Cb side of the resin sheet 1C, at a position spaced apart from the interlayer connection conductor 20C. In other words, the conductor layer 2B" and the conductor layer 2C are electrically connected via the interlayer connection conductor 20D.

[0159] In this way, in the laminated substrate 50, the conductor layer 2A and the conductor layer 2C are electrically connected via the interlayer connection conductor 20A, the conductor layer 2B', and the interlayer connection conductor 20C. In addition, in the laminated substrate 50, the conductor layer 2A and the conductor layer 2C are also electrically connected via the interlayer connection conductor 20B, the conductor layer 2B'', and the interlayer connection conductor 20D.

[0160] The interlayer connection conductor 20A is formed, for example, by plating the inner wall of a via hole that penetrates the resin sheet 1B in the thickness direction but does not penetrate the conductor layer 2B' in the thickness direction and reaches the conductor layer 2B', or by filling it with a conductive paste and then performing a heat treatment.

[0161] The interlayer connection conductors 20B, 20C, and 20D are formed in the same manner as the interlayer connection conductor 20A, except that they are formed at different positions.

[0162] When the interlayer connection conductors 20A, 20B, 20C, and 20D are formed by plating, examples of metals constituting each interlayer connection conductor include copper, tin, silver, etc., and among these, copper is preferred.

[0163] When interlayer connection conductors 20A, 20B, 20C, and 20D are formed by heat treatment of a conductive paste, examples of metals contained in each interlayer connection conductor include copper, tin, and silver. Among these, each interlayer connection conductor preferably contains copper, and more preferably contains copper and tin. For example, when interlayer connection conductor 20A contains copper and tin and conductor layer 2B' is made of copper foil, interlayer connection conductor 20A and conductor layer 2B' undergo an alloying reaction at low temperatures, making electrical conduction between them easier. The same applies to other combinations of interlayer connection conductors and conductor layers.

[0164] When the interlayer connection conductors 20A, 20B, 20C, and 20D are formed by heat treatment of a conductive paste, the resin contained in each interlayer connection conductor preferably includes at least one thermosetting resin selected from the group consisting of epoxy resin, phenolic resin, polyimide resin, silicone resin or modified resin thereof, and acrylic resin, or at least one thermoplastic resin selected from the group consisting of polyamide resin, polystyrene resin, polymethacrylic resin, polycarbonate resin, and cellulose-based resin.

[0165] The laminated substrate 50 is used, for example, as an electronic circuit board.

[0166] In the laminated substrate 50, the conductor layer 2B may be a signal line that transmits a signal. That is, the laminated substrate 50 may have the conductor layer 2B as a signal line that transmits a signal. In this case, the laminated substrate 50 forms a transmission line.

[0167] The laminated substrate 50 may have a conductor layer 2B as a signal line for transmitting a signal, and may have conductor layers 2A and 2C as ground electrodes, in which case the laminated substrate 50 forms a stripline-type transmission line.

[0168] When the laminated substrate 50 constitutes the above-mentioned transmission line, the conductor layer 2B may be a signal line that transmits a high-frequency signal.

[0169] When the laminated substrate 50 forms a transmission line, the resin sheet 1B containing the liquid crystal polymer 1Bg with a low dielectric constant and the resin sheet 1C containing the liquid crystal polymer 1Cg with a low dielectric constant are in contact with the conductor layer 2B, i.e., the signal line, which makes it easier to improve the transmission characteristics of the laminated substrate 50.

[0170] The laminated substrate 50 is manufactured, for example, by the following method.

[0171] <Step of producing a resin sheet with a conductor layer> 6, 7, and 8 are cross-sectional views schematically illustrating steps of producing a resin sheet with a conductor layer in one example of a method for producing a laminated substrate of the present invention.

[0172] 6, a conductor layer-attached resin sheet 10A is produced in which a conductor layer 2A is provided adjacent to the first main surface 1Aa of a resin sheet 1A. At this time, for example, the conductor layer 2A is pressure-bonded to the first main surface 1Aa of the resin sheet 1A.

[0173] As shown in FIG. 7, a conductor layer-attached resin sheet 10B is produced in which conductor layers 2B, 2B', and 2B'' are provided adjacent to the first main surface 1Ba of the resin sheet 1B. In this process, for example, the conductor layer is pressure-bonded to the first main surface 1Ba of the resin sheet 1B, and then the conductor layer is etched to pattern the conductor layers 2B, 2B', and 2B''. Alternatively, the conductor layers 2B, 2B', and 2B'' are prepared in advance, and each conductor layer is pressure-bonded to the first main surface 1Ba of the resin sheet 1B.

[0174] 8, a conductor layer-attached resin sheet 10C is produced in which a conductor layer 2C is provided adjacent to the first main surface 1Ca of the resin sheet 1C. At this time, for example, the conductor layer 2C is pressure-bonded to the first main surface 1Ca of the resin sheet 1C.

[0175] <Process for forming via holes> 9 and 10 are cross-sectional views schematically illustrating a step of forming a via hole in an example of a method for manufacturing a laminated substrate according to the present invention.

[0176] 9, a via hole 21A is formed in a conductor layer-attached resin sheet 10B so as to penetrate the resin sheet 1B in the thickness direction but not the conductor layer 2B′ in the thickness direction, and to reach the conductor layer 2B′, so that a part of the conductor layer 2B′ is exposed from the via hole 21A.

[0177] Furthermore, a via hole 21B is formed in the conductor layer-attached resin sheet 10B at a position spaced apart from the position where the via hole 21A is to be formed, so as to penetrate the resin sheet 10B in the thickness direction but not the conductor layer 2B'' in the thickness direction and reach the conductor layer 2B''. As a result, a part of the conductor layer 2B'' is exposed from the via hole 21B.

[0178] In this way, the via holes 21A and 21B are formed in the resin sheet 10B with a conductor layer. At this time, the via holes 21A and 21B may be formed at the same time or at different times.

[0179] 10, a via hole 21C is formed in a resin sheet 10C with a conductor layer so as to penetrate the resin sheet 1C in the thickness direction but not the conductor layer 2C in the thickness direction and reach the conductor layer 2C, whereby a part of the conductor layer 2C is exposed from the via hole 21C.

[0180] Furthermore, a via hole 21D is formed in the conductor layer-attached resin sheet 10C at a position spaced apart from the position where the via hole 21C is to be formed, so as to penetrate the resin sheet 10C in the thickness direction but not the conductor layer 2C in the thickness direction and reach the conductor layer 2C, thereby exposing a part of the conductor layer 2C from the via hole 21D.

[0181] In this way, the via holes 21C and 21D are formed in the resin sheet 10C with a conductor layer. At this time, the via holes 21C and 21D may be formed at the same time or at different times.

[0182] When forming the via holes 21A, 21B, 21C, and 21D, it is preferable to irradiate the resin sheet with the conductor layer with laser light from the resin sheet side.

[0183] <Process of filling conductive paste> 11 and 12 are cross-sectional views schematically illustrating a step of filling a conductive paste in an example of a method for producing a laminated substrate of the present invention.

[0184] 11, in a resin sheet 10B with a conductor layer, a conductive paste 22A is filled into a via hole 21A. In addition, in a resin sheet 10B with a conductor layer, a conductive paste 22B is filled into a via hole 21B. At this time, the conductive paste 22A and the conductive paste 22B may be filled at the same time or at different times.

[0185] 12, in a resin sheet 10C with a conductor layer, a conductive paste 22C is filled into a via hole 21C. In addition, in a resin sheet 10C with a conductor layer, a conductive paste 22D is filled into a via hole 21D. At this time, the conductive pastes 22C and 22D may be filled at the same time or at different times.

[0186] Examples of methods for filling the conductive paste 22A, the conductive paste 22B, the conductive paste 22C, and the conductive paste 22D include a screen printing method and a vacuum filling method.

[0187] The conductive paste 22A, the conductive paste 22B, the conductive paste 22C, and the conductive paste 22D each contain, for example, a metal and a resin.

[0188] Examples of metals contained in each of the conductive pastes 22A, 22B, 22C, and 22D include copper, tin, silver, etc. Among these, each of the conductive pastes preferably contains copper, and more preferably contains copper and tin.

[0189] The resin contained in each of the conductive pastes 22A, 22B, 22C, and 22D preferably includes at least one thermosetting resin selected from the group consisting of epoxy resin, phenolic resin, polyimide resin, silicone resin or modified resin thereof, and acrylic resin, or at least one thermoplastic resin selected from the group consisting of polyamide resin, polystyrene resin, polymethacrylic resin, polycarbonate resin, and cellulose-based resin.

[0190] Each of the conductive pastes 22A, 22B, 22C, and 22D may further contain a vehicle, a solvent, a thixotropic agent, an activator, and the like.

[0191] Examples of the vehicle include rosin-based resins made from rosin and derivatives thereof such as modified rosin, synthetic resins made from rosin and derivatives thereof such as modified rosin, and mixtures of these resins.

[0192] Examples of rosin-based resins made from rosin and derivatives thereof such as modified rosin include gum rosin, tall rosin, wood rosin, polymerized rosin, hydrogenated rosin, formylated rosin, rosin ester, rosin-modified maleic acid resin, rosin-modified phenolic resin, rosin-modified alkyd resin, and various other rosin derivatives.

[0193] Examples of synthetic resins made of rosin and derivatives thereof such as modified rosin include polyester resins, polyamide resins, phenoxy resins, and terpene resins.

[0194] Examples of solvents include alcohols, ketones, esters, ethers, aromatic solvents, and hydrocarbons. Specific examples of these solvents include benzyl alcohol, ethanol, isopropyl alcohol, butanol, diethylene glycol, ethylene glycol, glycerin, ethyl cellosolve, butyl cellosolve, ethyl acetate, butyl acetate, butyl benzoate, diethyl adipate, dodecane, tetradecene, α-terpineol, terpineol, 2-methyl-2,4-pentanediol, 2-ethylhexanediol, toluene, xylene, propylene glycol monophenyl ether, diethylene glycol monohexyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diisobutyl adipate, hexylene glycol, cyclohexanedimethanol, 2-terpinyloxyethanol, 2-dihydroterpinyloxyethanol, and mixtures thereof. Among these, terpineol, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, and diethylene glycol monoethyl ether are preferred.

[0195] Examples of thixotropic agents include hydrogenated castor oil, carnauba wax, amides, hydroxy fatty acids, dibenzylidene sorbitol, bis(p-methylbenzylidene)sorbitols, beeswax, stearic acid amide, hydroxystearic acid ethylene bisamide, etc. Furthermore, these thixotropic agents may contain, as necessary, fatty acids such as caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, and behenic acid, hydroxy fatty acids such as 1,2-hydroxystearic acid, antioxidants, surfactants, amines, etc.

[0196] Examples of the activator include amine hydrohalides, organic halogen compounds, organic acids, organic amines, and polyhydric alcohols.

[0197] Examples of amine hydrohalides include diphenylguanidine hydrobromide, diphenylguanidine hydrochloride, cyclohexylamine hydrobromide, ethylamine hydrochloride, ethylamine hydrobromide, diethylaniline hydrobromide, diethylaniline hydrochloride, triethanolamine hydrobromide, and monoethanolamine hydrobromide.

[0198] Examples of the organic halogen compound include chlorinated paraffin, tetrabromoethane, dibromopropanol, 2,3-dibromo-1,4-butanediol, 2,3-dibromo-2-butene-1,4-diol, and tris(2,3-dibromopropyl)isocyanurate.

[0199] Examples of organic acids include malonic acid, fumaric acid, glycolic acid, citric acid, malic acid, succinic acid, phenylsuccinic acid, maleic acid, salicylic acid, anthranilic acid, glutaric acid, suberic acid, adipic acid, sebacic acid, stearic acid, abietic acid, benzoic acid, trimellitic acid, pyromellitic acid, and dodecanoic acid.

[0200] Examples of organic amines include monoethanolamine, diethanolamine, triethanolamine, tributylamine, aniline, and diethylaniline.

[0201] Examples of polyhydric alcohols include erythritol, pyrogallol, and ribitol.

[0202] <Step of forming interlayer connection conductors> FIG. 13 is a cross-sectional view showing a step of forming an interlayer connection conductor in an example of a method for producing a laminated substrate of the present invention.

[0203] As shown in Fig. 13, a conductor layer-equipped resin sheet 10A, a conductor layer-equipped resin sheet 10B filled with conductive paste 22A and conductive paste 22B, and a conductor layer-equipped resin sheet 10C filled with conductive paste 22C and conductive paste 22D are laminated in this order in the lamination direction. At this time, the resin sheets are laminated so that the surface (upper surface) of the conductor layer-equipped resin sheet 10A facing the conductor layer 2A is in contact with the surface (lower surface) of the conductor layer-equipped resin sheet 10B facing the resin sheet 1B, and so that the surface (upper surface) of the conductor layer-equipped resin sheet 10B facing the conductor layer 2B' and conductor layer 2B" is in contact with the surface (lower surface) of the conductor layer-equipped resin sheet 10C facing the resin sheet 1C. For ease of explanation, Fig. 13 shows the conductor layer-equipped resin sheets spaced apart from each other.

[0204] The obtained laminate is then subjected to a hot press process by applying heat and pressure in the stacking direction. This pressure-bonds the conductor layer-equipped resin sheet 10A to the conductor layer-equipped resin sheet 10B, and the conductor layer-equipped resin sheet 10B to the conductor layer-equipped resin sheet 10C. Furthermore, the conductive pastes 22A, 22B, 22C, and 22D solidify during the hot press process to become the interlayer connection conductors 20A, 20B, 20C, and 20D, respectively. In this manner, the interlayer connection conductors 20A, 20B, 20C, and 20D are formed in the via holes 21A, 21B, 21C, and 21D, respectively.

[0205] When forming the interlayer connection conductors 20A, 20B, 20C, and 20D, instead of filling the via holes with conductive paste, the inner walls of the via holes may be plated with a metal such as copper, tin, or silver.

[0206] In the above, an example has been given of a mode in which, when forming an interlayer connection conductor, a via hole formed so as to penetrate a resin sheet in the thickness direction but reach a conductor layer without penetrating the conductor layer in the thickness direction is filled with a conductive paste or subjected to a plating process. However, an interlayer connection conductor may also be formed by filling a via hole formed so as to penetrate both a resin sheet and a conductor layer in the thickness direction with a conductive paste or by plating.

[0207] In this way, the laminated substrate 50 shown in FIG. 5 is manufactured. [Example]

[0208] Examples will be given below that more specifically disclose the resin composition of the present invention and the resin sheet of the present invention, but the present invention is not limited to the following examples.

[0209] [Examples 1 to 8] The resin compositions and resin sheets of Examples 1 to 8 were produced by the following methods.

[0210] First, a molten resin composition was produced by melt-kneading the liquid crystal polymer shown in Table 1 and the inorganic filler shown in Table 1 in a twin-screw extruder. The contents of the liquid crystal polymer and the inorganic filler in the resin composition were as shown in Table 1.

[0211] The molten resin composition was then extruded from a T-die and cooled to form the resin composition into a sheet.

[0212] [Comparative Examples 1 to 6] Resin compositions and resin sheets of Comparative Examples 1 to 6 were produced in the same manner as in Examples 1 to 8, except that the liquid crystal polymers and inorganic fillers shown in Table 2 were used.

[0213] Comparative Example 7 The resin composition of Comparative Example 7 was produced using the liquid crystal polymer shown in Table 2 and the inorganic filler shown in Table 2, and then the resin sheet of Comparative Example 7 was produced according to Production Example 1 described in Patent Document 3.

[0214] The liquid crystal polymers A and B shown in Tables 1 and 2 were as follows. Liquid crystal polymer A: Copolymer of 73 mol% p-hydroxybenzoic acid and 27 mol% 6-hydroxy-2-naphthoic acid Liquid crystal polymer B: Copolymer of 80 mol% p-hydroxybenzoic acid and 20 mol% 6-hydroxy-2-naphthoic acid

[0215] The properties of the inorganic fillers shown in Tables 1 and 2 were determined as follows.

[0216] <Specific surface area> First, the inorganic filler was degassed at 150°C for 20 minutes. Then, the specific surface area of ​​the inorganic filler was measured by the BET single-point method using a fully automatic specific surface area measuring device "Macsorb (registered trademark)" manufactured by Mountech Co., Ltd. Specifically, the specific surface area of ​​the inorganic filler was calculated from the amount of nitrogen gas adsorbed on the surface of the inorganic filler weighed out at approximately 0.1 g or more and 1.0 g or less.

[0217] <Maximum diameter> First, the inorganic filler was ultrasonically dispersed in ethanol. Then, the particle size distribution of the inorganic filler was measured by the laser diffraction / scattering method using a Horiba, Ltd., laser diffraction / scattering particle size distribution analyzer "LA-960." The particle size of the inorganic filler was measured as the equivalent circle diameter. The maximum particle size in the resulting particle size distribution of the inorganic filler was defined as the maximum diameter of the inorganic filler.

[0218] <Average particle size> First, the particle size distribution of the inorganic filler obtained when determining the maximum diameter of the inorganic filler was converted into a cumulative probability, and the volume-based cumulative particle size distribution of the inorganic filler was calculated. Then, the median diameter D50 and calculate the median diameter D 50 was defined as the average particle size of the inorganic filler.

[0219] <Thickness> First, an image of the inorganic filler was taken with a scanning electron microscope. Next, the obtained image of the inorganic filler was analyzed using analysis software to measure the dimensions of the inorganic filler in the short side direction. Then, the above-mentioned dimension measurement in the short side direction was performed on 100 inorganic fillers, and the average value of the obtained 100 measurements was defined as the thickness of the inorganic filler.

[0220] <Aspect ratio> First, an image of the inorganic filler was taken with a scanning electron microscope. Subsequently, the obtained image of the inorganic filler was subjected to image analysis using analysis software to measure the dimensions of the inorganic filler in the short side direction and the long side direction. The above-mentioned dimension measurements in the short side direction and the long side direction were performed on 100 inorganic fillers, and the average value of the 100 measurements obtained as the dimension in the short side direction was defined as A, and the average value of the 100 measurements obtained as the dimension in the long side direction was defined as B, where B / A was defined as the aspect ratio of the inorganic filler.

[0221] When the inorganic filler was spherical, the thickness and aspect ratio of the inorganic filler were not specified.

[0222] [evaluation] The following evaluations were carried out for Examples 1 to 8 and Comparative Examples 1 to 7. The results are shown in Tables 1 and 2.

[0223] <Melting point> Using a Hitachi High-Tech Science DSC7000X differential scanning calorimeter, the resin sheet was heated at a heating rate of 20°C / min until it was completely melted. The resulting melt was then cooled to 175°C at a heating rate of 20°C / min, and then heated again at a heating rate of 20°C / min. The temperature corresponding to the endothermic peak observed during this heating process was determined as the melting point of the resin composition contained in the resin sheet. When an endothermic peak was difficult to observe using the above-mentioned method, the melting point of the resin composition contained in the resin sheet was determined by texture observation under crossed Nicols conditions using a polarizing microscope.

[0224] <Melt tension> The melt tension of the resin composition contained in the resin sheet was measured at a temperature 20°C higher than the melting point of the resin composition determined by the above-mentioned method using a Capillograph (registered trademark) "F-1" manufactured by Toyo Seiki Seisaku-sho, Ltd. At this time, the barrel diameter of the cylinder was 9.55 mm, the capillary diameter was 1 mm, and the strand take-up speed was 150 m / min.

[0225] <Can it be made into a sheet?> Whether or not the resin composition could be molded into a sheet was evaluated according to the following criteria: When the resin composition could be molded into a sheet, the thickness of the obtained resin sheet was 100 μm. Pass: The resin composition did not break during the cooling process in the <step of molding the resin composition into a sheet>, and the resin composition could be molded into a sheet. Unacceptable: The resin composition broke during the cooling process in the <step of molding the resin composition into a sheet>, and the resin composition could not be molded into a sheet.

[0226] <Contamination> First, using a simultaneous thermogravimetry and differential thermal analyzer, the resin sheet was heated from room temperature to 600°C at a heating rate of 10°C / min in an air atmosphere, and then left at 600°C for 45 minutes to remove the resin components (liquid crystal polymer, etc.) from the resin sheet. Then, the inorganic components remaining after the resin components were removed were subjected to elemental analysis using a transmission electron microscope-energy dispersive X-ray analysis (SEM-EDX) to evaluate the presence or absence of contamination in the resin sheet according to the following criteria. Yes: Iron was detected as a result of elemental analysis of inorganic components. No: No iron was detected in the elemental analysis of inorganic components.

[0227] <Water absorption rate> First, five 50 mm x 50 mm samples were cut out from the resin sheet. Next, the five samples were placed in an oven set to 130°C and left for 30 minutes, and then placed in a desiccator and cooled to room temperature. The total weight M1 of the five samples was then measured. Next, the five samples were completely immersed in distilled water at room temperature and left for 24 hours. The five samples were then removed from the distilled water, and water droplets on the surface of each sample were wiped off. The total weight M2 of the five samples was then measured. The calculated value "100 x (M2 - M1) / M1" (unit: %) was then calculated, and this calculated value was taken as the water absorption rate of the resin sheet. The criteria for determining the water absorption rate were as follows: ◎ (Excellent): Water absorption rate was 0.05% or less. ◯ (Good): The water absorption rate was higher than 0.05% and 0.10% or less.

[0228] <Tensile elongation at break> A tensile test of the resin sheet was performed in accordance with ASTM D882. The dimension of the resin sheet in the tensile direction before the tensile test was defined as L1, and the dimension at the time the resin sheet broke during the tensile test was defined as L2. The calculated value was "100 × (L2 - L1) / L1" (unit: %). In this evaluation, the resin sheet was tensile in the machine direction (MD) of the resin sheet, which corresponds to the direction in which the resin composition is extruded from the T-die when the resin sheet is produced, and the transverse direction (TD) perpendicular to the machine direction of the resin sheet. Five tensile tests were performed in each direction, and the above-mentioned calculated value was obtained. The average of these calculated values ​​was defined as the tensile elongation at break of the resin sheet. The machine direction and transverse direction of the resin sheet were directions included in the in-plane direction perpendicular to the thickness direction. The evaluation criteria for tensile elongation at break were as follows. ◎ (Excellent): Tensile elongation at break was 10% or more. ◯ (Good): The tensile elongation at break was 5% or more and less than 10%. × (bad): The tensile elongation at break was less than 5%.

[0229] <Linear expansion coefficient in the in-plane direction> First, a 20 mm x 4 mm sample was cut from the resin sheet and placed on the probe of a Seiko Instruments Inc. thermomechanical analyzer with a chuck distance of 10 mm. Next, the sample was heated to 170°C at a heating rate of 40°C / min while applying a 5 g load, and then cooled to 30°C at a cooling rate of 10°C / min. The change in the chuck distance over the temperature range from 100°C to 50°C during the cooling process was measured to determine the linear expansion coefficient of the resin sheet. In this evaluation, the linear expansion coefficients of the resin sheet sample in the machine direction (MD) and the transverse direction (TD) were determined using the method described above, and the average of these values ​​was defined as the linear expansion coefficient in the in-plane direction of the resin sheet. The criteria for determining the linear expansion coefficient in the in-plane direction of the resin sheet were as follows. ◎ (Excellent): The linear expansion coefficient in the in-plane direction was within the range of 16±4 ppm / K. ◯ (Good): The linear expansion coefficient in the in-plane direction was outside the range of 16±4 ppm / K, but was within the range of 16±8 ppm / K. × (bad): The linear expansion coefficient in the in-plane direction was outside the range of 16±8 ppm / K.

[0230] [Table 1]

[0231] [Table 2]

[0232] As shown in Table 1, when the specific surface area of ​​the inorganic filler is 30m 2 / cm 3 In Examples 1 to 8, which satisfied all of the following requirements: the thickness of the resin composition was 100 μm or less, the maximum diameter of the inorganic filler was 100 μm or less, and the content of the inorganic filler was 0.1 vol% or more and 60 vol% or less, the resin composition could be molded into a sheet by melt extrusion without generating contamination.

[0233] The resin compositions of Examples 1 to 8 had a melt tension of 1.0 mN or more at a temperature 20° C. higher than the melting point of the resin composition.

[0234] Among Examples 1 to 8, the inorganic filler had a specific surface area of ​​20 m 2 / cm 3 In the resin sheets of Examples 2, 3, 5, 6, 7, and 8, the specific surface area of ​​the inorganic filler is 20 m 2 / cm 3 The water absorption rate was lower than that of the resin sheets of Examples 1 and 4, which were larger than that of the resin sheets of Examples 1 and 4.

[0235] Among Examples 1 to 8, the resin sheets of Examples 3 and 6, which had a tensile elongation at break of 5% or more and less than 10%, did not crack when bent by 90°. Furthermore, among Examples 1 to 8, the resin sheets of Examples 1, 2, 4, 5, 7, and 8, which had a tensile elongation at break of 10% or more, did not crack when bent by 180°.

[0236] Among Examples 1 to 8, the resin sheets of Examples 2, 3, 5, and 6, which had in-plane linear expansion coefficients outside the range of 16±4 ppm / K but within the range of 16±8 ppm / K, had in-plane linear expansion coefficients close to that of copper foil (approximately 16 ppm / K), and therefore warping was unlikely to occur when the resin sheets and copper foils were used to form resin sheets or laminated substrates with conductor layers. Furthermore, among Examples 1 to 8, the resin sheets of Examples 1, 4, 7, and 8, which had in-plane linear expansion coefficients within the range of 16±4 ppm / K, had in-plane linear expansion coefficients close enough to that of copper foil (approximately 16 ppm / K), and therefore warping did not occur when the resin sheets and copper foils were used to form resin sheets or laminated substrates with conductor layers.

[0237] On the other hand, as shown in Table 2, when the specific surface area of ​​the inorganic filler is 30m 2 / cm 3 In Comparative Examples 1 and 4, which were not described below, the resin compositions could not be molded into a sheet by melt extrusion.

[0238] As shown in Table 2, in Comparative Examples 2 and 5, in which the maximum diameter of the inorganic filler was not 100 μm or less, the resin composition could not be molded into a sheet by melt extrusion.

[0239] As shown in Table 2, in Comparative Examples 3 and 6 in which the content of the inorganic filler was not 0.1 vol % or more and 60 vol % or less, the resin composition could not be molded into a sheet by melt extrusion.

[0240] As shown in Table 2, in Comparative Example 7, although the resin composition could be molded into a sheet, contamination occurred in the obtained resin sheet.

[0241] As described above, the water absorption rate, tensile breaking elongation, and in-plane linear expansion coefficient could not be evaluated because resin sheets could not be produced in Comparative Examples 1 to 6. In addition, in Comparative Example 7, the water absorption rate, tensile breaking elongation, and in-plane linear expansion coefficient were not evaluated because of the influence of contamination.

[0242] The present specification discloses the following:

[0243] <1> A liquid crystal polymer, an inorganic filler, The specific surface area of ​​the above inorganic filler is 30m 2 / cm 3 is as follows: The maximum diameter of the inorganic filler is 100 μm or less, A resin composition characterized in that the content of the inorganic filler is 0.1 vol% or more and 60 vol% or less.

[0244] <2> The specific surface area of ​​the above inorganic filler is 20m 2 / cm 3 Below is the <1> The resin composition according to claim 1.

[0245] <3> The inorganic filler is plate-shaped. <1> or <2> The resin composition according to claim 1.

[0246] <4> The inorganic filler has an average particle size of 0.1 μm or more and 30 μm or less, The thickness of the inorganic filler is 1 nm or more and 1000 nm or less, The aspect ratio of the inorganic filler is 2 or more and 100 or less. <3> The resin composition according to claim 1.

[0247] <5> The melt tension at a temperature 20°C higher than the melting point of the resin composition is 1.0 mN or more. <1> ~ <4> The resin composition according to any one of the preceding claims.

[0248] <6> <1> ~ <5> A resin sheet comprising the resin composition according to any one of the above items.

[0249] <7> <6> a resin sheet according to the above item (1), A resin sheet with a conductor layer, comprising: a conductor layer adjacent to at least one main surface side of the resin sheet.

[0250] <8> <7> A laminated substrate comprising the resin sheet with a conductor layer according to claim 1.

[0251] <9> Liquid crystal polymer and a specific surface area of ​​30m 2 / cm 3 preparing a resin composition containing an inorganic filler having a maximum diameter of 100 μm or less, the inorganic filler content being 0.1 vol% or more and 60 vol% or less; and forming the resin composition into a sheet by melt extrusion. [Explanation of symbols]

[0252] 1, 1', 1'', 1A, 1B, 1C Resin sheet 1a, 1Aa, 1Ba, 1Ca First main surface of resin sheet 1b, 1Ab, 1Bb, 1Cb: Second main surface of resin sheet 1g, 1Ag, 1Bg, 1Cg Liquid Crystal Polymer 1h, 1h'', 1Ah, 1Bh, 1Ch Inorganic filler 1s, 1s', 1s'', 1As, 1Bs, 1Cs resin composition 2, 2A, 2B, 2B', 2B'', 2C conductor layer 3. Surface treatment layer 10, 10A, 10B, 10C Resin sheet with conductor layer 20A, 20B, 20C, 20D Interlayer connecting conductor 21A, 21B, 21C, 21D via holes 22A, 22B, 22C, 22D Conductive Paste 50 Laminated board

Claims

1. A resin composition for use in a melt extrusion method, comprising: a liquid crystal polymer as the main component with the highest weight percentage; an inorganic filler, The specific surface area of ​​the inorganic filler is 9 m 2 / cm 3 or more, and ２ / cm ３ is as follows: The maximum diameter of the inorganic filler is 100 μm or less, A resin composition characterized in that the content of the inorganic filler is 0.1 vol % or more and 60 vol % or less.

2. The specific surface area of ​​the inorganic filler is 9 m 2 / cm 3 or more, and ２ / cm ３ The resin composition according to claim 1, wherein:

3. The resin composition according to claim 1 or 2, wherein the inorganic filler is plate-shaped.

4. The inorganic filler has an average particle size of 0.1 μm or more and 30 μm or less, The thickness of the inorganic filler is 1 nm or more and 1000 nm or less, The resin composition according to claim 3 , wherein the inorganic filler has an aspect ratio of 2 or more and 100 or less.

5. The resin composition according to claim 1 or 2, wherein the resin composition has a melt tension of 1.0 mN or more at a temperature 20° C. higher than the melting point of the resin composition.

6. A resin sheet comprising the resin composition according to claim 1 or 2.

7. The resin sheet according to claim 6; a conductor layer adjacent to at least one main surface of the resin sheet.

8. A laminated substrate comprising the resin sheet with a conductor layer according to claim 7.

9. The liquid crystal polymer as the main component with the highest weight percentage and the specific surface area of ​​9 m 2 / cm 3 or more, 30 m ２ / cm ３ preparing a resin composition containing an inorganic filler having a particle size of 0.1 vol% or more and a maximum diameter of 100 μm or less, wherein the content of the inorganic filler is 0.1 vol% or more and 60 vol% or less; and forming the resin composition into a sheet by melt extrusion.

Images