Laminate and film

Abstract

One aspect of the present invention relates to a laminate comprising: a substrate having a first insulating layer; a second insulating layer laminated on the first main surface side of the substrate; the first insulating layer is laminated on the first principal surface side of the substrate, and the third insulating layer is laminated on the second principal surface side of the substrate, the thickness of the first insulating layer is 600-2000 [mu] m, the bending modulus of the first insulating layer at 25 DEG C is 25 GPa or more, the thicknesses of the second insulating layer and the third insulating layer are respectively 5-70 [mu] m, and the tensile storage moduli of the second insulating layer and the third insulating layer at 25 DEG C are respectively 0.5-4 GPa.

Description

Technical Field

[0001] This invention relates to laminates and membranes. Background Technology

[0002] Electronic devices are increasingly becoming more multifunctional, high-performance, thinner, and smaller. Along with this, mounting technologies for wiring boards on electronic devices are rapidly developing, including higher integration, higher wiring density, and multilayering, requiring that wiring boards prevent mounting defects. Therefore, wiring boards, especially in semiconductor packaging substrates, require minimal warpage during component mounting and package assembly. Materials for wiring boards designed to suppress this warpage include, for example, the resin compositions described in Patent Documents 1 and 2.

[0003] Patent Documents 1 and 2 disclose a resin composition containing an epoxy resin and a curing agent, wherein the average linear thermal expansion coefficient of the cured product obtained by curing the resin composition under specified conditions, divided by the crosslinking density of the cured product, satisfies a specified relationship. Patent Documents 1 and 2 disclose resin compositions that can yield cured products with suppressed warping.

[0004] To suppress the warping of the wiring board, the warping of the layers in the wiring board must also be suppressed.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Publication No. 2021-161205

[0008] Patent Document 2: Japanese Patent Publication No. 2021-161206 Summary of the Invention

[0009] The present invention was made in view of the above circumstances, and its object is to provide a laminate in which warpage is suppressed, and a membrane capable of forming a laminate in which warpage is suppressed.

[0010] One aspect of the present invention relates to a laminate comprising: a substrate having a first insulating layer; a second insulating layer laminated on a first main surface of the substrate; and a third insulating layer laminated on a second main surface of the substrate, wherein the thickness of the first insulating layer is 600–2000 μm, and the flexural modulus of the first insulating layer at 25°C is 25 GPa or more; the thicknesses of the second and third insulating layers are 5–70 μm, and the tensile storage moduli of the second and third insulating layers at 25°C are 0.5–4 GPa, respectively.

[0011] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings. Attached Figure Description

[0012] Figure 1 This is a schematic cross-sectional view illustrating an example of a laminated body according to an embodiment of the present invention.

[0013] Figure 2 This is a schematic cross-sectional view illustrating another example of a laminated body according to an embodiment of the present invention.

[0014] Figure 3 It means possessing Figure 1 A schematic cross-sectional view of an example of a metal foil-coated laminate of a laminated body shown.

[0015] Figure 4 It means possessing Figure 2 A schematic cross-sectional view of an example of a metal foil laminate of a laminated body shown.

[0016] Figure 5 It means possessing Figure 1 A schematic cross-sectional view of an example of a stacked wiring board.

[0017] Figure 6 It means possessing Figure 2 A schematic cross-sectional view of an example of a stacked wiring board. Detailed Implementation

[0018] To address the increasing functionality of electronic devices and the need to accommodate larger semiconductor chips, semiconductor packaging substrates are trending towards larger sizes. Furthermore, they are also trending towards thinner designs. However, this trend towards larger and thinner semiconductor packaging substrates has led to a problem: semiconductor packages formed by mounting semiconductor chips on these substrates are prone to warping, resulting in poor mounting. Therefore, it is desirable to minimize warping during component mounting and package assembly, even with larger and thinner semiconductor packaging substrates. To reduce warping of semiconductor packaging substrates, it is possible to further increase the elastic modulus and further decrease the coefficient of thermal expansion (CTE). For example, in the case of wiring boards, it is possible to form a wiring board with an insulating layer that has a higher elastic modulus and a lower CTE. Examples of materials used to obtain this insulating layer include epoxy resin compositions with low linear expansion coefficients and high crosslinking densities, as described in Patent Documents 1 and 2. Since the cured resin composition can suppress warpage, the insulating layer containing the cured resin composition can also suppress warpage. On the other hand, to improve the mounting reliability of semiconductor packages, it is required to improve not only the reliability of mounting semiconductor chips on the semiconductor package substrate (primary mounting) but also the reliability of mounting semiconductor packages on the motherboard (secondary mounting). If the method of suppressing warpage of the semiconductor package substrate is adopted by simply increasing the elastic modulus of the insulating layer and reducing the coefficient of thermal expansion, the reliability during primary mounting can be improved. However, the strain between the substrate and the motherboard where the semiconductor package is mounted increases, which may result in a failure to improve the reliability during secondary mounting. Therefore, for wiring boards used as semiconductor package substrates, it is required not only to increase the elastic modulus of the insulating layer and reduce the coefficient of thermal expansion to suppress warpage, but also to suppress warpage by employing other methods (such as using a laminate of multiple insulating layers as the insulating layer). Furthermore, as wiring boards used as semiconductor packaging substrates, multilayer wiring boards, such as those in which a rewiring layer (a build-up layer for multilayering) is formed on a wiring board that serves as an inner layer substrate, are also used. It is required that even such multilayer wiring boards can suppress warping.

[0019] The inventors have conducted various studies and found that the above-mentioned objectives can be achieved through the following invention, namely, providing a laminate with suppressed warpage and a membrane capable of being made from a laminate with suppressed warpage.

[0020] To suppress the increase in strain between the semiconductor package and the motherboard, which could compromise reliability during secondary mounting, and to suppress warping of the semiconductor package substrate, the inventors conducted various studies on the structure of the semiconductor package substrate. As a result, the inventors focused on using a laminate composed of multiple insulating layers as the insulating layer in a substrate used for a semiconductor package substrate. Furthermore, they discovered that by adjusting the thickness and elastic modulus of each of the multiple insulating layers, warping of the laminate could be suppressed. Through various studies, the inventors found that the above-mentioned objective can be achieved through the following invention, namely, providing a laminate in which warping is suppressed.

[0021] The following describes the embodiments of the present invention, but the present invention is not limited to these embodiments.

[0022] [Layered Body]

[0023] like Figure 1 As shown, the laminate 10 according to an embodiment of the present invention includes: a substrate 11 having a first insulating layer 111; a second insulating layer 12 laminated on a first main surface 11a side of the substrate 11; and a third insulating layer 13 laminated on a second main surface 11b side of the substrate 11. In the laminate 10, the thickness of the first insulating layer 111 is 600 to 2000 μm, and its flexural modulus at 25°C is 25 GPa or more. Furthermore, the thickness of each of the second insulating layer 12 and the third insulating layer 13 is 5 to 70 μm, and their tensile storage moduli at 25°C are 0.5 to 4 GPa, respectively. With the laminate 10, warping can be suppressed. That is, in the laminate formed by stacking the second insulating layer 12 and the third insulating layer 13 on the substrate 11 as described in the laminate 10, warpage is suppressed not only by increasing the elastic modulus of the substrate 11 and reducing the coefficient of thermal expansion, but also by keeping the thickness and elastic modulus of each layer within the aforementioned range. It should be noted that... Figure 1 This is a schematic cross-sectional view illustrating an example of a laminate (laminated body 10) according to an embodiment of the present invention. Figure 2 This is a schematic cross-sectional view showing another example of a laminate (the laminate 20) according to an embodiment of the present invention.

[0024] The substrate 11 only needs to have the first insulating layer 111, such as Figure 1 As shown, the substrate 11 can be composed of the first insulating layer 111, or it can be a substrate 11 having the first insulating layer 111 and also having other layers and wiring, etc. Specifically, as Figure 2As shown, a wiring board having the first insulating layer 111 and wiring 112 disposed on the first insulating layer 111 can also be used as the substrate 11. That is, the laminate 20 according to other embodiments of the present invention is a laminate that uses a wiring board having the first insulating layer 111 and wiring 112 as the substrate 11. As the laminate 20, other laminates similar to the laminate 10 besides using the wiring board as the substrate 11 can be listed.

[0025] From the viewpoint of improving the warpage suppression effect based on the substrate 11, the first insulating layer 111 preferably comprises a fibrous substrate. Furthermore, the first insulating layer 111 can be, for example, a layer comprising a cured resin composition (it should be noted that, hereinafter, the resin composition in the cured product contained in the first insulating layer 111 is also referred to as the first resin composition). Therefore, the first insulating layer 111 is preferably a layer comprising a cured first resin composition and a fibrous substrate. Furthermore, the first insulating layer 111 is preferably a cured prepreg. Examples of prepregs include, for example, the first resin composition or a semi-cured product of the first resin composition; and prepregs of the fibrous substrate. That is, from the viewpoint of obtaining the first insulating layer 111 appropriately, it is preferable to cure a prepreg comprising the first resin composition or a semi-cured product of the first resin composition to form the first insulating layer 111. It should be noted that a semi-cured product is a substance in which the resin composition has been cured to a state where it can be further cured. That is, a semi-cured substance is a substance that causes the resin composition to be in a semi-cured state (a state of partial curing). For example, if the resin composition is heated, the viscosity initially decreases slowly, and then begins to cure, with the viscosity slowly increasing. In this case, the state from the start of the viscosity increase to the point before complete curing can be listed as a semi-cured substance. Furthermore, the first resin composition and the fibrous substrate will be described later.

[0026] As described above, the second insulating layer 12 is stacked on the first main surface 11a side of the substrate 11, specifically, as Figure 1 and Figure 2As shown, the second insulating layer 12 is preferably laminated in contact with the first main surface 11a of the substrate 11. Furthermore, unlike the first insulating layer 111, the second insulating layer 12 preferably does not contain a fibrous substrate. Moreover, the second insulating layer 12 can be, for example, a layer comprising a cured resin composition (it should be noted that, hereinafter, the resin composition in the cured product contained in the second insulating layer 12 is also referred to as the second resin composition). Therefore, the second insulating layer 12 is preferably a layer comprising a cured second resin composition. Furthermore, the second insulating layer 12 is preferably a cured film. Examples of such films include, for example, films comprising the second resin composition or a semi-cured product of the second resin composition. That is, from the viewpoint of obtaining the second insulating layer 12, it is preferable to cure the film comprising the second resin composition or a semi-cured product of the second resin composition to form the second insulating layer 12. Furthermore, the film is a film used to form the second and third insulating layers of a laminate, the laminate comprising: the substrate; the second insulating layer, laminated on the first main surface of the substrate; and the third insulating layer, laminated on the second main surface of the substrate. That is, the film is a buildup film suitable for the substrate. Furthermore, the third insulating layer 13, like the second insulating layer 12, can be, for example, a layer containing a cured resin composition (it should be noted that, hereinafter, the resin composition in the cured composition contained in the third insulating layer 13 is also referred to as the third resin composition). That is, the third insulating layer 13 is the same as the second insulating layer 12, except that the third resin composition is used instead of the second resin composition. The second insulating layer 12 and the third insulating layer 13 can be layers with the same thickness, elastic modulus, and composition, or they can be different layers, provided that their respective thicknesses are 5 to 70 μm and their respective tensile storage moduli at 25°C are 0.5 to 4 GPa. It should be noted that the second resin composition and the third resin composition will be described later.

[0027] The thickness of the first insulating layer 111 is 600–2000 μm, preferably 700–1600 μm, and more preferably 900–1400 μm. Furthermore, the thicknesses of the second insulating layer 12 and the third insulating layer 13 are 5–70 μm, preferably 10–60 μm, and more preferably 10–40 μm. The thicknesses of the second insulating layer 12 and the third insulating layer 13 can be the same or different, as long as they are both 5–70 μm. Moreover, the ratios of the thicknesses of the second insulating layer 12 and the third insulating layer 13 to the thickness of the first insulating layer 111 [(thickness of the second insulating layer 12) / (thickness of the first insulating layer 111), and (thickness of the third insulating layer 13) / (thickness of the first insulating layer 111)] are preferably 0.0025–0.116 times, more preferably 0.00625–0.066 times. If the first insulating layer 111 is too thin, it tends to be unable to adequately suppress warpage. This is believed to be because, relative to the thickness of the second insulating layer 12 and the third insulating layer 13, the warpage suppression effect of the substrate 11 based on the relatively high elastic modulus of the first insulating layer 111 is reduced. Furthermore, if the first insulating layer 111 is too thick, even if warpage is suppressed, this is done by increasing the elastic modulus of the insulating layer of the semiconductor package substrate and reducing the coefficient of thermal expansion, making it difficult to suppress warpage while simultaneously suppressing a decrease in secondary mounting capability. Furthermore, if the second insulating layer 12 and the third insulating layer 13 are too thin, they also tend to be unable to adequately suppress warpage. This is believed to be because, even with the second insulating layer 12 and the third insulating layer 13, the warpage suppression effect based on these layers cannot be fully utilized. It should be noted that if the second insulating layer 12 and the third insulating layer 13 are relatively thick, there is a tendency to suppress warpage of the semiconductor packaging substrate unless the coefficients of thermal expansion of the second insulating layer 12 and the third insulating layer 13 are close to those of the first insulating layer 111. Furthermore, if the second insulating layer 12 and the third insulating layer 13 are too thick, there is a tendency to be unable to sufficiently suppress warpage. This is believed to be because the thickness of the first insulating layer 111 is relatively thin, thereby reducing the warpage suppression effect of the substrate 11 based on the relatively high elastic modulus of the first insulating layer 111. Therefore, it can be seen that as long as the thicknesses of the first insulating layer 111, the second insulating layer 12, and the third insulating layer 13 are within the aforementioned ranges, a laminate with further suppressed warpage can be obtained.

[0028] The flexural modulus of the first insulating layer 111 at 25°C (hereinafter referred to as "flexural modulus at 25°C") is 25 GPa or more, preferably 27-45 GPa, and more preferably 30-40 GPa. The tensile storage modulus of the second insulating layer 12 and the third insulating layer 13 at 25°C (hereinafter referred to as "tensile storage modulus at 25°C") is 0.5-4 GPa, preferably 0.5-3 GPa, and more preferably 0.5-2 GPa. The tensile storage modulus of the second insulating layer 12 and the third insulating layer 13 can be the same or different as long as they are both below 0.5-4 GPa. The ratios of the tensile storage modulus of the second insulating layer 12 and the third insulating layer 13 to the flexural modulus of the first insulating layer 111 [(tensile storage modulus of the second insulating layer 12) / (flexural modulus of the first insulating layer 111), and (tensile storage modulus of the third insulating layer 13) / (flexural modulus of the first insulating layer 111)] are preferably 0.16 times or less, more preferably 0.066 to 0.11 times. As long as the flexural modulus of the first insulating layer 111, the tensile storage modulus of the second insulating layer 12, and the tensile storage modulus of the third insulating layer 13 are within the above ranges, a laminate with further suppressed warping can be obtained. It should be noted that the flexural modulus here refers to the flexural modulus of the test object at 25°C. Examples include the flexural modulus calculated from the stress-strain curve obtained by performing a three-point bending test on the test object at 25°C. Furthermore, the tensile storage modulus here refers to the storage modulus of the object being measured at 25°C, such as the value obtained by measuring the tensile modulus at 25°C using the Dynamic Mechanical Analysis (DMA) method.

[0029] The coefficient of thermal expansion of the first insulating layer 111 at 50–260°C (hereinafter referred to as "coefficient of thermal expansion") is preferably 10 ppm / °C or less, more preferably 9 ppm / °C or less, and even more preferably 6 ppm / °C or less. A lower coefficient of thermal expansion of the first insulating layer 111 is better; however, in practice, its limit value is often around 1 ppm / °C. Therefore, 1 ppm / °C or more can be cited as an example of the lower limit of the coefficient of thermal expansion range of the first insulating layer 111. Furthermore, the coefficients of thermal expansion of the second insulating layer 12 and the third insulating layer 13 are preferably 50 ppm / °C or less, more preferably 10–40 ppm / °C. The coefficients of thermal expansion of the second insulating layer 12 and the third insulating layer 13 may be the same or different. Moreover, the coefficients of thermal expansion of the first insulating layer 111 are preferably all less than the coefficients of thermal expansion of the second insulating layer 12 and the third insulating layer 13. The coefficient of thermal expansion of the laminate 10 is preferably 11 ppm / ℃ or less, more preferably 1 to 7.2 ppm / ℃, and even more preferably 1 to 7 ppm / ℃. As long as the coefficients of thermal expansion of the first insulating layer 111, the second insulating layer 12, the third insulating layer 13, and the laminate 10 are all within the above ranges, a laminate with further suppressed warpage can be obtained. Specifically, it is known that the smaller the absolute value of the difference between the coefficient of thermal expansion of the laminate 10 and the coefficient of thermal expansion of the first insulating layer 111, the more suppressed the warpage. Specifically, a laminate 10 with an absolute value of 0 to 0.35 ppm / ℃ can be obtained. That is, this absolute value is preferably 0 to 0.35 ppm / ℃, more preferably 0 to 0.3 ppm / ℃, and even more preferably 0 to 0.2 ppm / ℃. It should be noted that the coefficients of thermal expansion of the second insulating layer 12 and the third insulating layer 13 refer to the coefficients of thermal expansion in the range of 50 to 260°C. Examples include, for instance, the average coefficient of thermal expansion in the range of 50 to 260°C calculated from the coefficient of thermal expansion measured by temperature change using the TMA (Thermo-mechanical analysis) method. Similarly, the coefficients of thermal expansion of the first insulating layer 111 and the laminate 10 refer to the coefficients of thermal expansion in the range of 50 to 260°C. Examples include, for instance, the average coefficient of thermal expansion in the range of 50 to 260°C calculated from the displacement measured by temperature change using the DIC (Digital Image Correlation) method.

[0030] The dielectric loss factors of the second insulating layer 12 and the third insulating layer 13 are preferably 0.004 or less, more preferably 0.003 or less, and even more preferably 0.002 or less. A lower dielectric loss factor for the second insulating layer 12 and the third insulating layer 13 is preferable; in practice, a value of around 0.0005 is common. Therefore, the dielectric loss factors of the second insulating layer 12 and the third insulating layer 13 are preferably 0.0005 to 0.004, more preferably 0.0005 to 0.003, and even more preferably 0.0005 to 0.002.

[0031] The relative permittivity of the second insulating layer 12 and the third insulating layer 13 is preferably 3 or less, more preferably 2.8 or less, and even more preferably 2.7 or less. A relatively low relative permittivity of the second insulating layer 12 and the third insulating layer 13 is preferable; in practice, a value of around 2 is common. Therefore, the relative permittivity of the second insulating layer 12 and the third insulating layer 13 is preferably 2 to 3, more preferably 2 to 2.8, and even more preferably 2 to 2.7.

[0032] If the dielectric loss factor and relative permittivity of the second insulating layer 12 and the third insulating layer 13 stacked on the first insulating layer 111 are within the above range, the signal transmission speed in the wiring board having the stacked body can be improved, and signal transmission loss can be reduced.

[0033] It should be noted that the relative permittivity and dielectric loss factor here refer to the relative permittivity and dielectric loss factor of each layer at a frequency of 10 GHz. Examples include the relative permittivity and dielectric loss factor of each layer at a frequency of 10 GHz measured by the resonant cavity perturbation method.

[0034] (Resin composition)

[0035] The first resin composition, the second resin composition, and the third resin composition (each resin composition) are not particularly limited as long as they are cured products of each resin composition satisfying the above-described structure. Each resin composition preferably contains an inorganic filler. The first insulating layer 111, the second insulating layer 12, and the third insulating layer (each insulating layer) each contain cured products of the respective resin compositions; therefore, each resin composition also contains a curable resin. Therefore, each resin composition preferably contains both a curable resin and an inorganic filler.

[0036] In the second and third resin compositions, the content of the inorganic filler material is preferably 70% by mass or less, more preferably 20% to 70% by mass, relative to the total amount of each of the second and third resin compositions excluding the inorganic filler material. If the content of the inorganic filler material in the second and third resin compositions is within the above range, excellent processability suitable for drilling can be achieved, and a laminate with suppressed warpage can be obtained. In the second and third resin compositions, the content of the curable resin is preferably 30% to 80% by mass, relative to the total amount of each of the second and third resin compositions excluding the inorganic filler material.

[0037] As described above, each resin composition contains a curable resin and may also contain a curing agent. That is, each resin composition preferably contains the curable resin, the curing agent, and an inorganic filler. The curable resin is not particularly limited and examples include, for instance, polyphenylene ether compounds. That is, each resin composition preferably contains the polyphenylene ether compound, the curing agent, and an inorganic filler.

[0038] Polyphenylene ether compounds

[0039] Examples of polyphenylene ether compounds include, for example, polyphenylene ether compounds having reactive carbon-carbon unsaturated bonds; more specifically, examples include polyphenylene ether compounds having at least one of the groups shown in formula (1) and formula (2) within the molecule. More specifically, examples include modified polyphenylene ether compounds whose terminals are modified by at least one of the groups shown in formula (1) and formula (2).

[0040]

[0041] In formula (1), p represents 0 to 10, Z represents arylene, and R1 to R3 each independently represent a hydrogen atom or an alkyl group.

[0042]

[0043] In formula (2), R4 represents a hydrogen atom or an alkyl group.

[0044] In formula (1), p represents 0 to 10. Furthermore, Z represents an arylene group. Additionally, R1 to R3 are independent. That is, R1 to R3 can be the same group or different groups. Furthermore, R1 to R3 represent hydrogen atoms or alkyl groups.

[0045] It should be noted that in the above formula (1), when p is 0, it means that Z is directly bonded to the end of the polyphenylene ether.

[0046] The arylene group is not particularly limited. Examples of such arylene groups include monocyclic aromatic groups such as phenylene; and polycyclic aromatic groups such as naphthalene rings, which are not monocyclic. Furthermore, the arylene group may also include derivatives formed by substituting the hydrogen atoms bonded to the aromatic ring with functional groups such as alkenyl, alkynyl, formyl, alkylcarbonyl, alkenylcarbonyl, or alkynylcarbonyl. The alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include methyl, ethyl, propyl, hexyl, and decyl.

[0047] In formula (2), R4 represents a hydrogen atom or an alkyl group. The alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include methyl, ethyl, propyl, hexyl, and decyl.

[0048] Preferred examples of the group represented by formula (1) include vinylbenzyl (ethylene benzyl) and vinylphenyl, as shown in formula (3) below. Furthermore, examples of the vinylbenzyl group include o-vinylbenzyl, p-vinylbenzyl, and meta-vinylbenzyl. Furthermore, examples of the group represented by formula (2) include acryloyl and methacryloyl.

[0049]

[0050] The polyphenylene ether compound has at least one of the groups shown in formula (1) and formula (2) within its molecule. These groups may be one or more. The polyphenylene ether compound may have, for example, any one of o-vinylbenzyl, p-vinylbenzyl, and m-vinylbenzyl, or two or three of them.

[0051] The polyphenylene ether compound has a polyphenylene ether chain in the molecule, preferably having a repeating unit as shown in formula (4) below.

[0052]

[0053] In formula (4), t represents 1 to 50. Furthermore, R5 to R8 are independent. That is, R5 to R8 can be the same group or different groups. Additionally, R5 to R8 represent hydrogen atoms, alkyl, alkenyl, alkynyl, formyl, alkylcarbonyl, alkenylcarbonyl, or alkynylcarbonyl. Preferably, hydrogen atoms and alkyl groups are used.

[0054] Among R5 to R8, the listed functional groups are specifically listed as follows.

[0055] The alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include methyl, ethyl, propyl, hexyl, and decyl.

[0056] The alkenyl group is not particularly limited, but is preferably an alkenyl group with 2 to 18 carbon atoms, and more preferably an alkenyl group with 2 to 10 carbon atoms. Specifically, examples include vinyl, allyl, and 3-butenyl.

[0057] The alkynyl group is not particularly limited, but is preferably an alkynyl group with 2 to 18 carbon atoms, and more preferably an alkynyl group with 2 to 10 carbon atoms. Specifically, examples include ethynyl and prop-2-yn-1-yl (propynyl).

[0058] The alkyl carbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkyl group. For example, it is preferred to be an alkyl carbonyl group with 2 to 18 carbon atoms, and more preferably an alkyl carbonyl group with 2 to 10 carbon atoms. Specifically, examples include acetyl, propionyl, butyryl, isobutyryl, neopentyl, hexanoyl, octanoyl, and cyclohexyl carbonyl.

[0059] The alkenyl carbonyl group is not particularly limited as long as it is a carbonyl group that has been substituted with an alkenyl group. For example, an alkenyl carbonyl group with 3 to 18 carbon atoms is preferred, and an alkenyl carbonyl group with 3 to 10 carbon atoms is more preferred. Specifically, examples include acryloyl, methacryl, and crotonyl.

[0060] The alkynyl carbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkynyl group. For example, an alkynyl carbonyl group with 3 to 18 carbon atoms is preferred, and an alkynyl carbonyl group with 3 to 10 carbon atoms is more preferred. Specifically, examples include propynyl groups, etc.

[0061] The weight-average molecular weight (Mw) of the polyphenylene ether compound is not particularly limited. Specifically, it is preferably 500 to 5000, more preferably 800 to 4000, and even more preferably 1000 to 3000. It should be noted that here, the weight-average molecular weight can be any value obtained by measuring the molecular weight using a conventional molecular weight determination method, such as the value obtained by gel permeation chromatography (GPC). Furthermore, when the polyphenylene ether compound has repeating units as shown in formula (4) within its molecule, t is preferably a value that makes the weight-average molecular weight of the polyphenylene ether compound fall within the above-mentioned range. Specifically, t is preferably 1 to 50.

[0062] If the weight-average molecular weight of the polyphenylene ether compound is within the above-mentioned range, the polyphenylene ether compound not only possesses the excellent low dielectric properties of polyphenylene ether, but also exhibits superior heat resistance and formability of the cured product. This is believed to be based on the following reasons. In conventional polyphenylene ethers, if their weight-average molecular weight is within the above-mentioned range, the molecular weight is relatively low, thus tending to reduce the heat resistance of the cured product. Regarding this point, it is believed that since the polyphenylene ether compound involved in this embodiment has at least one of the groups shown in formula (1) and formula (2) within its molecule, the cured product can obtain sufficiently high heat resistance. Furthermore, it is believed that if the weight-average molecular weight of the polyphenylene ether compound is within the above-mentioned range, the formability is also excellent because the molecular weight is relatively low. Therefore, it is believed that this polyphenylene ether compound can achieve the effect of not only superior heat resistance of the cured product, but also excellent formability.

[0063] The average number (number of terminal functional groups) of at least one of the groups represented by formula (1) and formula (2) in each molecule of the polyphenylene ether compound is not particularly limited. Specifically, the number of terminal functional groups is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1.5 to 3. If the number of terminal functional groups is too small, it tends to be difficult to obtain a cured product with sufficient heat resistance. In addition, if the number of terminal functional groups is too large, the reactivity becomes too high, which may result in adverse conditions such as reduced shelf life of the resin composition or reduced flowability of the resin composition. That is, if the polyphenylene ether compound is used, problems with formability may occur due to insufficient flowability, for example, forming defects such as voids during multilayer molding, making it difficult to obtain a printed wiring board with high reliability.

[0064] It should be noted that the number of terminal functional groups in a polyphenylene ether compound can be exemplified by a numerical value representing the average number of substituents in each molecule of all polyphenylene ether compounds present in 1 mole of the compound. This number of terminal functional groups can be determined, for example, by measuring the number of residual hydroxyl groups in the resulting polyphenylene ether compound and calculating the reduction in the number of hydroxyl groups compared to the polyphenylene ether before modification. This reduction in the number of hydroxyl groups compared to the polyphenylene ether before modification is the number of terminal functional groups. Furthermore, the number of residual hydroxyl groups in the polyphenylene ether compound can be determined by adding a quaternary ammonium salt (tetraethylammonium hydroxide) associated with hydroxyl groups to a solution of the polyphenylene ether compound and measuring the UV absorbance of the mixed solution.

[0065] The intrinsic viscosity of the polyphenylene ether compound is not particularly limited. Specifically, it is preferably 0.03 to 0.12 dl / g, more preferably 0.04 to 0.11 dl / g, and even more preferably 0.06 to 0.095 dl / g. If the intrinsic viscosity is too low, there is a tendency for a low molecular weight, and it is difficult to obtain low dielectric properties such as a low dielectric constant and a low dielectric loss factor. Furthermore, if the intrinsic viscosity is too high, the viscosity is high, making it difficult to obtain sufficient flowability, and there is a tendency for reduced formability of the cured product. Therefore, if the intrinsic viscosity of the polyphenylene ether compound is within the above range, excellent heat resistance and formability of the cured product can be achieved.

[0066] It should be noted that the intrinsic viscosity here refers to the intrinsic viscosity measured in dichloromethane at 25°C. More specifically, it is the value obtained by measuring a 0.18 g / 45 ml dichloromethane solution (liquid temperature 25°C) using a viscometer. Examples of such viscometers include the AVS500 Visco System manufactured by Schott.

[0067] Examples of the polyphenylene ether compounds include those shown in formula (5) and those shown in formula (6). Furthermore, these polyphenylene ether compounds can be used alone or in combination.

[0068]

[0069]

[0070] In equations (5) and (6), R9~R 16 and R 17 ~R 24 Each of the following groups independently represents a hydrogen atom, alkyl, alkenyl, alkynyl, formyl, alkylcarbonyl, alkenylcarbonyl, or alkynylcarbonyl. X1 and X2 each independently represent the group shown in formula (1) or formula (2) above. A and B represent the repeating units shown in formula (7) and formula (8) below, respectively. Furthermore, in formula (6), Y represents a straight-chain, branched, or cyclic hydrocarbon with 20 or fewer carbon atoms.

[0071]

[0072]

[0073] In equations (7) and (8), m and n represent 0 to 20, respectively. 25 ~R 28 and R 29 ~R 32Each can independently represent a hydrogen atom, alkyl, alkenyl, alkynyl, formyl, alkyl carbonyl, alkenyl carbonyl, or alkynyl carbonyl.

[0074] The polyphenylene ether compounds shown in formula (5) and formula (6) are not particularly limited as long as they satisfy the above-described composition. Specifically, in formulas (5) and (6), as described above, R9 to R 16 and R 17 ~R 24 Each is independent. That is, R9 to R 16 and R 17 ~R 24 They can be the same group or different groups. Furthermore, R9 to R... 16 and R 17 ~R 24 It represents a hydrogen atom, alkyl, alkenyl, alkynyl, formyl, alkylcarbonyl, alkenylcarbonyl, or alkynylcarbonyl. Among them, hydrogen atom and alkyl are preferred.

[0075] In equations (7) and (8), m and n are preferably represented as 0 to 20, as described above. Furthermore, the sum of m and n is preferably represented as a value between 1 and 30. Therefore, more preferably, m represents 0 to 20, n represents 0 to 20, and the sum of m and n represents 1 to 30. Furthermore, R 25 ~R 28 and R 29 ~R 32 Each is independent. That is, R 25 ~R 28 and R 29 ~R 32 They can be the same group or different groups. Furthermore, R... 25 ~R 28 and R 29 ~R 32 It represents a hydrogen atom, alkyl, alkenyl, alkynyl, formyl, alkylcarbonyl, alkenylcarbonyl, or alkynylcarbonyl. Among them, hydrogen atom and alkyl are preferred.

[0076] R9~R 32 R5 to R8 are the same as those in equation (4) above.

[0077] In formula (6), as described above, Y is a straight-chain, branched, or cyclic hydrocarbon with 20 or fewer carbon atoms. Examples of Y include groups such as those shown in formula (9) below.

[0078]

[0079] In equation (9), R 33 and R 34Each can be represented independently as a hydrogen atom or an alkyl group. Examples of alkyl groups include methyl. In addition, examples of groups represented by formula (9) include methylene, methylmethylene and dimethylmethylene, among which dimethylmethylene is preferred.

[0080] In formulas (5) and (6), X1 and X2 are each independently a group represented by formula (1) or a group represented by formula (2). It should be noted that in the polyphenylene ether compound shown in formula (5) and the polyphenylene ether compound shown in formula (6), X1 and X2 can be the same group or different groups.

[0081] As a more specific example of the polyphenylene ether compound represented by formula (5), examples such as the polyphenylene ether compound represented by formula (10) below can be cited.

[0082]

[0083] As more specific examples of the polyphenylene ether compound represented by formula (6), examples include the polyphenylene ether compound represented by formula (11) below and the polyphenylene ether compound represented by formula (12) below.

[0084]

[0085]

[0086] In equations (10) to (12) above, m and n are the same as m and n in equations (7) and (8) above. Furthermore, in equations (10) and (11) above, R1 to R3, p and Z are the same as R1 to R3, p and Z in equation (1) above. Furthermore, in equations (11) and (12) above, Y is the same as Y in equation (6) above. Furthermore, in equation (12) above, R4 is the same as R1 in equation (2) above.

[0087] The method for synthesizing the polyphenylene ether compound is not particularly limited as long as it can synthesize a polyphenylene ether compound having at least one of the groups shown in formula (1) and formula (2) within the molecule. Here, a method for synthesizing a modified polyphenylene ether compound whose end is modified by at least one of the groups shown in formula (1) and formula (2) can be described. As a method, specifically, a method of reacting polyphenylene ether with a compound having at least one of the groups shown in formula (1) and formula (2) and a halogen atom can be listed. As the halogen atom, specifically, chlorine atom, bromine atom, iodine atom and fluorine atom can be listed, with chlorine atom being preferred. As the compound having at least one of the groups shown in formula (1) and formula (2) and a halogen atom, more specifically, o-chloromethylstyrene, p-chloromethylstyrene, m-chloromethylstyrene, etc. The compound having at least one of the groups shown in formula (1) and formula (2) and a halogen atom can be used alone or in combination of two or more. For example, o-chloromethylstyrene, p-chloromethylstyrene, and m-chloromethylstyrene can be used alone, or two or three can be used in combination.

[0088] The polyphenylene ether used as a raw material is not particularly limited as long as it can ultimately synthesize the specified modified polyphenylene ether compound. Specifically, examples include compounds whose main component is a polyphenylene ether containing "2,6-dimethylphenol" and "at least one of bifunctional and trifunctional phenols," or poly(2,6-dimethyl-1,4-phenylene ether). Furthermore, a bifunctional phenol is a phenolic compound having two phenolic hydroxyl groups within its molecule, such as tetramethylbisphenol A. A trifunctional phenol is a phenolic compound having three phenolic hydroxyl groups within its molecule.

[0089] The methods described above can be used to synthesize the modified polyphenylene ether compound. Specifically, the polyphenylene ether as described above is dissolved in a solvent with a compound having at least one of the groups shown in formula (1) and formula (2) and a halogen atom, and the mixture is stirred. Thus, the polyphenylene ether reacts with a compound having at least one of the groups shown in formula (1) and formula (2) and a halogen atom to obtain the modified polyphenylene ether compound used in this embodiment.

[0090] The reaction is preferably carried out in the presence of an alkali metal hydroxide. It is believed that this operation allows the reaction to proceed well. The reason for this is that the alkali metal hydroxide acts as a dehydrohalogenating agent, specifically as a dehydrochlorinating agent. That is, it is believed that the alkali metal hydroxide causes hydrogen halide to decouple from the phenolic group of polyphenylene ether and the compound bonded with at least one of the groups shown in formula (1) and formula (2) and a halogen atom, thereby replacing the hydrogen atom of the phenolic group of polyphenylene ether with the oxygen atom of the phenolic group.

[0091] Alkali metal hydroxides are not particularly limited in their application as long as they can function as dehalogenating agents; examples include sodium hydroxide. Furthermore, alkali metal hydroxides are typically used in aqueous solutions, specifically as an aqueous solution of sodium hydroxide.

[0092] The reaction time and reaction temperature, etc., vary depending on the compound bonded with at least one of the groups shown in formula (1) and formula (2) and a halogen atom, and are not particularly limited as long as the conditions allow the above reaction to proceed well. Specifically, the reaction temperature is preferably room temperature to 100°C, more preferably 30 to 100°C. In addition, the reaction time is preferably 0.5 to 20 hours, more preferably 0.5 to 10 hours.

[0093] The solvent used in the reaction is not particularly limited as long as it can dissolve the polyphenylene ether in a compound bonded with at least one of the groups shown in formula (1) and formula (2) and a halogen atom, and does not hinder the reaction of the polyphenylene ether with the compound bonded with at least one of the groups shown in formula (1) and formula (2) and a halogen atom. Specifically, toluene and the like can be cited as examples.

[0094] It is preferable to carry out the above reaction in the presence of both an alkali metal hydroxide and a phase transfer catalyst. That is, it is preferable to carry out the above reaction in the presence of both an alkali metal hydroxide and a phase transfer catalyst. This operation is believed to facilitate the reaction. This is based on the following reasoning: The phase transfer catalyst is a catalyst that has the function of introducing an alkali metal hydroxide, is soluble in both a polar solvent phase such as water and a non-polar solvent phase such as an organic solvent, and is capable of moving between these phases. Specifically, it is believed that when an aqueous sodium hydroxide solution is used as the alkali metal hydroxide and an organic solvent such as toluene, which is incompatible with water, is used as the solvent, even if the aqueous sodium hydroxide solution is added dropwise to the solvent used for the reaction, the solvent and the aqueous sodium hydroxide solution will separate, and the sodium hydroxide is difficult to migrate into the solvent. Therefore, it is believed that the aqueous sodium hydroxide solution added as an alkali metal hydroxide is unlikely to help promote the reaction. In contrast, it is believed that if the reaction is carried out in the presence of both an alkali metal hydroxide and a phase transfer catalyst, the alkali metal hydroxide will migrate into the solvent under the condition of being introduced by the phase transfer catalyst, and the aqueous sodium hydroxide solution becomes more likely to help promote the reaction. Therefore, it is believed that the above reaction will proceed more smoothly in the presence of alkali metal hydroxides and phase transfer catalysts.

[0095] There are no particular limitations on phase transfer catalysts; examples include quaternary ammonium salts such as tetra-n-butylammonium bromide.

[0096] The resin compositions preferably include: the modified polyphenylene ether compound obtained as described above, as the polyphenylene ether compound.

[0097] Hardener

[0098] The curing agent is a curing agent that can react with the polyphenylene ether compound to cure the resin composition containing the polyphenylene ether compound. Furthermore, the curing agent is not particularly limited as long as it is a curing agent other than the "polybutadiene compound having an epoxy group in the molecule" and "styrene-based block copolymer" described later, and is a curing agent that can cure the "resin composition containing the polyphenylene ether compound". Examples of such curing agents include: styrene, styrene derivatives, compounds having an acryloyl group in the molecule, compounds having a methacryloyl group in the molecule, compounds having a vinyl group in the molecule, compounds having an allyl group in the molecule, compounds having an acenaphthene structure in the molecule, compounds having a maleimide group in the molecule, and isocyanurate compounds having an isocyanurate group in the molecule.

[0099] Examples of styrene derivatives include bromostyrene and dibromostyrene.

[0100] The compound having an acryloyl group within its molecule is an acrylate compound. Examples of such acrylate compounds include monofunctional acrylate compounds having one acryloyl group within their molecule, and polyfunctional acrylate compounds having two or more acryloyl groups within their molecule. Examples of monofunctional acrylate compounds include methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate. Examples of polyfunctional acrylate compounds include diacrylate compounds such as tricyclodecanediethanol diacrylate.

[0101] The compound having a methacryl group within its molecule is a methacrylate compound. Examples of such methacrylate compounds include monofunctional methacrylate compounds having one methacryl group within their molecule, and polyfunctional methacrylate compounds having two or more methacryl groups within their molecule. Examples of monofunctional methacrylate compounds include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. Examples of polyfunctional methacrylate compounds include dimethacrylate compounds such as tricyclodecanediethanol dimethacrylate, and trimethacrylate compounds such as trimethylolpropane trimethacrylate.

[0102] The compound having a vinyl group within its molecule is a vinyl compound. Examples of such vinyl compounds include monofunctional vinyl compounds having one vinyl group within their molecule (monovinyl compounds) and polyfunctional vinyl compounds having two or more vinyl groups within their molecule. Examples of such polyfunctional vinyl compounds include divinylbenzene and polybutadiene (polybutadiene oligomers). Examples of such polybutadiene oligomers include B1000 manufactured by Nippon Soda Co., Ltd.

[0103] The compound having an allyl group within its molecule is an allyl compound. Examples of such allyl compounds include monofunctional allyl compounds having one allyl group within their molecule, and polyfunctional allyl compounds having two or more allyl groups within their molecule. Examples of such polyfunctional allyl compounds include, for example, triallyl isocyanurate compounds such as triallyl isocyanurate (TAIC), diallyl bisphenol compounds, and diallyl phthalate (DAP).

[0104] The compound having an intramolecular acenaphthene structure is an acenaphthene compound. Examples of such acenaphthene compounds include: acenaphthene, alkylacenaphthenes, haloacenaphthenes, and phenylacenaphthenes. Examples of such alkylacenaphthenes include: 1-methylacenaphthene, 3-methylacenaphthene, 4-methylacenaphthene, 5-methylacenaphthene, 1-ethylacenaphthene, 3-ethylacenaphthene, 4-ethylacenaphthene, 5-ethylacenaphthene, etc. Examples of such haloacenaphthenes include: 1-chloroacenaphthene, 3-chloroacenaphthene, 4-chloroacenaphthene, 5-chloroacenaphthene, 1-bromoacenaphthene, 3-bromoacenaphthene, 4-bromoacenaphthene, 5-bromoacenaphthene, etc. Examples of phenylacenaphthenes include 1-phenylacenaphthene, 3-phenylacenaphthene, 4-phenylacenaphthene, and 5-phenylacenaphthene. The acenaphthene compound can be a monofunctional acenaphthene compound having one acenaphthene structure within the molecule, as described above, or a polyfunctional acenaphthene compound having two or more acenaphthene structures within the molecule.

[0105] The compound having a maleimide group within its molecule is a maleimide compound. Examples of such maleimide compounds include: monofunctional maleimide compounds having one maleimide group within their molecule; polyfunctional maleimide compounds having two or more maleimide groups within their molecule; and modified maleimide compounds. Examples of such modified maleimide compounds include: modified maleimide compounds in which a portion of the molecule is modified by an amine compound; modified maleimide compounds in which a portion of the molecule is modified by an organosilicon compound; and modified maleimide compounds in which a portion of the molecule is modified by both an amine compound and an organosilicon compound.

[0106] The compound having an isocyanurate group within the molecule is an isocyanurate compound. Examples of such isocyanurate compounds include compounds that further have an alkenyl group within the molecule (alkenyl isocyanurate compounds), such as triallyl isocyanurate compounds (TAIC).

[0107] In the above, the curing agent preferably comprises, for example, an allyl compound having an allyl group in the molecule. As the allyl compound, an allyl isocyanurate compound having two or more allyl groups in the molecule is preferred, and triallyl isocyanurate (TAIC) is more preferred.

[0108] Regarding the curing agent, it can be used alone or in combination of two or more.

[0109] The weight-average molecular weight of the curing agent is not particularly limited, but is preferably 100 to 5000, more preferably 100 to 4000, and even more preferably 100 to 3000. If the weight-average molecular weight of the curing agent is too low, there is a risk that the curing agent may easily volatilize from the compounding system of the resin composition. Furthermore, if the weight-average molecular weight of the curing agent is too high, there is a risk that the viscosity of the varnish of the resin composition and the melt viscosity during heat molding may become too high. Therefore, if the weight-average molecular weight of the curing agent is within this range, a resin composition with better heat resistance of the cured product can be obtained. The reason for this is that the resin composition containing the polyphenylene ether compound can be well cured through reaction with the polyphenylene ether compound. It should be noted that here, the weight-average molecular weight can be any value obtained by conventional molecular weight determination methods, such as values ​​measured by gel permeation chromatography (GPC).

[0110] Regarding the curing agent, the average number of functional groups (functional group number) in each molecule of the curing agent that contribute to the reaction with the polyphenylene ether compound varies depending on the weight-average molecular weight of the curing agent, and is preferably 1 to 20, more preferably 2 to 18. If the number of functional groups is too small, it tends to be difficult to obtain a cured product with sufficient heat resistance. Furthermore, if the number of functional groups is too large, the reactivity becomes too high, which may lead to adverse conditions such as reduced shelf life of the resin composition or reduced flowability of the resin composition.

[0111] Inorganic filler materials

[0112] Examples of inorganic fillers include materials added to improve the heat resistance and flame retardancy of the cured resin composition, without particular limitation. Furthermore, the presence of such inorganic fillers can further improve heat resistance and flame retardancy. The inorganic filler is not particularly limited as long as it is an inorganic filler that can be used as a component of the resin composition. Specifically, examples of such inorganic fillers include: silica fillers such as spherical silica, metal oxide fillers (alumina fillers, titanium dioxide fillers, and mica fillers, etc.), metal hydroxide fillers (aluminum hydroxide fillers, magnesium hydroxide fillers, etc.), barium titanate fillers, calcium titanate fillers, strontium titanate fillers, talc fillers, aluminum borate fillers, barium sulfate fillers, and calcium carbonate fillers. Among these, silica fillers, mica fillers, and talc fillers are preferred, and spherical silica fillers are more preferred. Furthermore, one type of inorganic filler can be used alone, or two or more can be used in combination. Furthermore, the inorganic filler material can be used directly or a surface-treated inorganic filler material treated with the silane coupling agent described later can be used.

[0113] The average particle size of the inorganic filler material is not particularly limited, but is preferably 0.05–10 μm, more preferably 0.1–5 μm. It should be noted that the average particle size here refers to the volume average particle size. The volume average particle size can be determined by, for example, laser diffraction.

[0114] Other ingredients

[0115] Each of the resin compositions may also contain components other than the curable resin and the curing agent (other components). Examples of other components in the resin compositions include, for example, polybutadiene compounds having epoxy groups in their molecules, styrene-based block copolymers, silane coupling agents, flame retardants, initiators, curing accelerators, defoamers, antioxidants, polymerization inhibitors, polymerization retardants, dispersants, homogenizers, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes or pigments, and lubricants. Furthermore, in addition to the polyphenylene ether compound, each of the resin compositions may also contain epoxy resins, unsaturated polyester resins, and thermosetting polyimide resins, etc. Moreover, the second and third resin compositions preferably contain styrene-based polymers as one of the other components. That is, examples of resin compositions containing, for example, the curable resin such as the polyphenylene ether compound, the curing agent, styrene-based polymers, and inorganic fillers.

[0116] ·Styrene polymers

[0117] The styrene-based polymer is not particularly limited to any styrene-based polymer that can be used as a resin in a resin composition for forming an insulating layer in a metal foil laminate or wiring board.

[0118] The styrene-based polymer is, for example, a polymer obtained by polymerizing monomers containing styrene-based monomers, and can be a styrene-based copolymer. Furthermore, examples of styrene-based copolymers include copolymers obtained by copolymerizing one or more of the aforementioned styrene-based monomers with one or more other monomers capable of copolymerizing with the aforementioned styrene-based monomers. The styrene-based copolymer can be a random copolymer or a block copolymer as long as it has a structure derived from the aforementioned styrene-based monomer within its molecule. Examples of block copolymers include: binary copolymers of a structure (repeating unit) derived from the aforementioned styrene-based monomer and the other monomers capable of copolymerizing (repeating unit); ternary copolymers of a structure (repeating unit) derived from the aforementioned styrene-based monomer, the other monomers capable of copolymerizing (repeating unit), and a structure (repeating unit) derived from the aforementioned styrene-based monomer; and ternary copolymers of a structure (repeating unit) derived from the aforementioned styrene-based monomer, comprising a random copolymer block (repeating unit) containing the other monomers capable of copolymerizing and a styrene-based monomer, and a structure (repeating unit) derived from the aforementioned styrene-based monomer. The styrene-based polymer can also be a hydrogenated styrene-based copolymer obtained by hydrogenating the aforementioned styrene-based copolymer. Furthermore, the styrene-based polymer is preferably at least partially hydrogenated. By containing at least a partially hydrogenated styrene-based polymer, a resin composition can be obtained that produces a cured product with superior adhesion to metal foil and superior dimensional stability. Alternatively, the styrene-based polymer can also be the styrene-based copolymer, the at least partially hydrogenated styrene-based polymer, or a substance modified with maleic anhydride on a portion of the hydrogenated styrene-based copolymer.

[0119] The styrene-based monomers are not particularly limited, and examples include styrene, styrene derivatives, substances in which some hydrogen atoms of the benzene ring in styrene are replaced by alkyl groups, substances in which some hydrogen atoms of the vinyl group in styrene are replaced by alkyl groups, vinyltoluene, α-methylstyrene, butylstyrene, dimethylstyrene, and isopropenyltoluene, etc. These styrene-based monomers can be used alone or in combination of two or more. Furthermore, the other monomers capable of copolymerization are not particularly limited, and examples include: olefins such as α-pinene, β-pinene, and dipentene; non-conjugated dienes such as 1,4-hexadiene and 3-methyl-1,4-hexadiene; and conjugated dienes such as 1,3-butadiene and 2-methyl-1,3-butadiene (isoprene), etc. These other monomers capable of copolymerization can be used alone or in combination of two or more.

[0120] More specifically, examples of the styrene-based polymers include methylstyrene (ethylene / butene) methylstyrene block copolymers, methylstyrene (ethylene-ethylene / propylene) methylstyrene block copolymers, styrene-isoprene block copolymers, hydrogenated styrene-isoprene-styrene block copolymers, styrene (ethylene / butene) styrene block copolymers, styrene (ethylene-ethylene / propylene) styrene block copolymers, styrene-butadiene-styrene block copolymers, styrene-isobutene-styrene block copolymers, styrene (butadiene / butene) styrene block copolymers, methylstyrene (styrene / butadiene random copolymer block) methylstyrene copolymers, styrene (styrene / butadiene random copolymer block) styrene copolymers, and at least a portion thereof hydrogenated hydrides.

[0121] As the styrene-based polymer, commercially available products can also be used, such as Tuftec P1500, Tuftec H1221, Tuftec H1041, Tuftec H1517, Tuftec M1913 manufactured by Asahi Kasei Corporation, and ASAPRENE T437 manufactured by Asahi Kasei Corporation.

[0122] The styrene-based polymer can be used alone or in combination of two or more of the styrene-based polymers exemplified above.

[0123] The weight-average molecular weight of the styrene-based polymer is preferably 1,000 to 300,000, more preferably 10,000 to 200,000. If the molecular weight is too low, the glass transition temperature or heat resistance of the cured resin composition tends to decrease. Furthermore, if the molecular weight is too high, the viscosity when the resin composition is made into a varnish-like form, or the viscosity of the resin composition during heat molding, tends to become too high. It should be noted that the weight-average molecular weight is any value obtained by a conventional molecular weight determination method; specifically, values ​​obtained using gel permeation chromatography (GPC) can be cited as examples.

[0124] By containing the styrene-based block copolymer in the resin composition, a resin composition that becomes a cured product with a low elastic modulus after curing can be obtained.

[0125] When each of the resin compositions contains the styrene-based polymer, the content of the styrene-based polymer is preferably 10 to 50% by mass relative to the total amount of each resin composition.

[0126] As described above, each of the resin compositions may also contain a flame retardant. By containing a flame retardant, the flame retardancy of the cured resin composition can be improved. The flame retardant is not particularly limited. Specifically, in the field of using halogenated flame retardants such as brominated flame retardants, preferred examples include ethylenedipentabromobenzene, ethylenebistetrabromoimide, decabromodiphenyl ether, and tetradecylbromodiphenoxybenzene, which have melting points of 300°C or higher. It is believed that by using halogenated flame retardants, halogen release at high temperatures can be suppressed, thus preventing a decrease in heat resistance. Furthermore, in fields requiring halogen-free properties, examples include phosphate ester-based flame retardants, phosphazene-based flame retardants, bisdiphenylphosphine-based flame retardants, and phosphinate-based flame retardants. Specific examples of phosphate ester-based flame retardants include polyphosphate esters of bis(xyl)phosphite. Specific examples of phosphazene-based flame retardants include phenoxyphosphazene. Specific examples of bis(diphenylphosphine)oxyflammable bis(xylenebis(diphenylphosphine)) is xylenebis(diphenylphosphine). Specific examples of hypophosphite-based flame retardants include, for example, metal hypophosphite salts of dialkyl aluminum hypophosphite. The illustrated flame retardants can be used alone or in combination.

[0127] As described above, each of the resin compositions may also contain a silane coupling agent. The silane coupling agent may be included in the resin composition or may be included as a silane coupling agent in which the inorganic filler material contained in the resin composition has been pre-treated. Preferably, the silane coupling agent is included as a silane coupling agent in which the inorganic filler material has been pre-treated; more preferably, it is included in this way, and the resin composition also contains the silane coupling agent. Furthermore, in the case of prepregs, the silane coupling agent may be included as a silane coupling agent in which the fibrous substrate has been pre-treated.

[0128] Examples of silane coupling agents include silane coupling agents having at least one functional group selected from the group consisting of vinyl, styrene, methacryl, acryloyl, and phenylamino. Specifically, examples of such silane coupling agents include compounds having at least one of vinyl, styrene, methacryl, acryloyl, and phenylamino as a reactive functional group and having a hydrolyzable group such as methoxy or ethoxy.

[0129] Regarding the silane coupling agent, examples of vinyl-containing silane coupling agents include vinyltriethoxysilane and vinyltrimethoxysilane. Examples of styrene-containing silane coupling agents include p-styrenetrimethoxysilane and p-styrenetriethoxysilane. Examples of methacryloxysilane coupling agents include 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, and 3-methacryloyloxypropylethyldiethoxysilane. Examples of acryloyloxypropyltrimethoxysilane include 3-acryloyloxypropyltrimethoxysilane and 3-acryloyloxypropyltriethoxysilane. Regarding the silane coupling agent, examples of silane coupling agents containing phenylamino groups include N-phenyl-3-aminopropyltrimethoxysilane and N-phenyl-3-aminopropyltriethoxysilane.

[0130] As described above, each of the resin compositions may also contain an initiator (reaction initiator). The resin composition can undergo a curing reaction even without a reaction initiator. However, depending on the process conditions, it may be difficult to raise the temperature until curing occurs, so a reaction initiator may be added. The reaction initiator is not particularly limited as long as it can promote the curing reaction between the polyphenylene ether compound and the curing agent. Specifically, examples include oxidants such as α,α'-bis(tert-butylperoxym-isopropyl)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne, benzoyl peroxide, 3,3',5,5'-tetramethyl-1,4-diphenol benzoquinone, chloroquinone, 2,4,6-tritert-butylphenoxy, tert-butylperoxyisopropyl monocarbonate, and azobisisobutyronitrile. Furthermore, metal carboxylic acid salts may be used in combination as needed. This can further promote the curing reaction. α,α'-bis(tert-butylperoxym-isopropyl)benzene is preferred. Because α,α'-bis(tert-butylperoxym-isopropyl)benzene has a relatively high reaction initiation temperature, it can suppress the promotion of the curing reaction during prepreg drying and other times when curing is not required, thus preventing a decrease in the shelf life of the resin composition. Furthermore, due to its low volatility, α,α'-bis(tert-butylperoxym-isopropyl)benzene does not volatilize during prepreg drying and storage, exhibiting good stability. In addition, the reaction initiator can be used alone or in combination of two or more.

[0131] As described above, each of the resin compositions may also contain a curing accelerator. The curing accelerator is not particularly limited as long as it can promote the curing reaction of the resin composition. Specifically, examples of curing accelerators include: imidazoles and their derivatives, organophosphorus compounds, amines such as secondary and tertiary amines, quaternary ammonium salts, organoboron compounds, and metal soaps. Examples of imidazoles include: 2-ethyl-4-methylimidazolium, 2-methylimidazolium, 2-phenyl-4-methylimidazolium, 2-phenylimidazolium, 1-benzyl-2-methylimidazolium, etc. Examples of organophosphorus compounds include: triphenylphosphine, diphenylphosphine, phenylphosphine, tributylphosphine, and trimethylphosphine, etc. Examples of amines include: dimethylbenzylamine, triethylenediamine, triethanolamine, 1,8-diazabicyclo(5,4,0)undecene-7 (DBU), etc. Examples of quaternary ammonium salts include tetrabutylammonium bromide, etc. Furthermore, examples of the organoboron compounds include tetraphenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate, and tetra-substituted phosphonium tetra-substituted borates such as tetraphenylphosphonium ethyltriphenylborate. Additionally, the metal soap refers to a fatty acid metal salt, which can be a linear or cyclic fatty acid metal salt. Specifically, examples of the metal soap include linear aliphatic metal salts with 6 to 10 carbon atoms and cyclic aliphatic metal salts. More specifically, examples include aliphatic metal salts formed from linear fatty acids such as stearic acid, lauric acid, ricinoleic acid, and octanoic acid, or cyclic fatty acids such as naphthenic acids, and metals such as lithium, magnesium, calcium, barium, copper, and zinc. For example, zinc octanoate can be cited. The curing accelerator can be used alone or in combination of two or more.

[0132] (Fibrous substrate)

[0133] As described above, the first insulating layer 111 preferably comprises a fibrous substrate. Furthermore, the second insulating layer 12 and the third insulating layer 13 preferably do not comprise a fibrous substrate, but sometimes they do. The fibrous substrate is not particularly limited; examples include glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and cotton linter paper. It should be noted that if glass cloth is used, a laminate with excellent mechanical strength can be obtained, and glass cloth that has undergone a flattening process is particularly preferred. As a flattening process, examples include continuously pressing the glass cloth with a pressure roller to compress the yarn into a flat shape. It should be noted that the thickness of the commonly used fibrous substrate is, for example, 0.01 mm or more and 0.3 mm or less. Furthermore, the glass fibers constituting the glass cloth are not particularly limited; examples include Q glass, NE glass, E glass, S glass, T glass, L glass, and L2 glass. In addition, the surface of the fibrous substrate can be surface-treated with a silane coupling agent. The silane coupling agent is not particularly limited, and examples include silane coupling agents that have at least one selected from the group consisting of vinyl, acryloyl, methacryl, styrene, amino, and epoxy groups within the molecule.

[0134] (Manufacturing method)

[0135] The method for manufacturing the laminate is not particularly limited as long as it can produce the laminate. For example, one method for manufacturing the laminate involves first heating a prepreg containing the first resin composition or a semi-cured product of the first resin composition to cure it. Then, a film containing the second resin composition or a semi-cured product of the second resin composition is overlapped on one side of the cured material (first insulating layer), and a film containing the third resin composition or a semi-cured product of the third resin composition is overlapped on the other side of the first insulating layer. The cured material (first insulating layer) with the overlapping films is then heated and pressurized to integrally laminate it. This yields the laminate. Furthermore, in this manufacturing method, instead of the cured material, a wiring board formed by forming wiring on the cured material is used, thereby enabling the manufacture of... Figure 2The laminate shown is further described above. Furthermore, a film containing a second resin composition or a semi-cured product of the first resin composition is overlapped on one side of the main surface of a prepreg containing the first resin composition or a semi-cured product of the first resin composition, and a film containing a third resin composition or a semi-cured product of the third resin composition is overlapped on the other side of the main surface of the prepreg. The prepreg with the overlapping films is heated and pressurized to integrally laminate it. The laminate can also be obtained by this manufacturing method. Furthermore, in manufacturing the laminate, by overlapping a metal foil on the cured film of the prepreg with the overlapping films, or by forming a metal layer on the cured film using a method called a semi-additive process (SAP), or by using a film with a metal foil as the film, it is possible to manufacture a metal foil-coated laminate having the laminate described below.

[0136] [Metal Foil Coated Laminate]

[0137] like Figure 3 As shown, a metal foil laminate 30 incorporating the laminate 10 according to an embodiment of the present invention includes: the laminate 10; and a metal layer 14 laminated on the laminate 10. Figure 3 As shown, the metal layer 14 can be stacked on both sides of the laminate 10, or on one side of the laminate 10. Furthermore, the laminate of the metal foil-coated laminate is not limited to the type shown. Figure 1 The laminate 10 shown can be any laminate involved in this embodiment; for example, it can also be as follows: Figure 2 The layered body 20 shown. That is, as... Figure 4 As shown, the metal-clad laminate can also be a metal-clad laminate 40 comprising: the laminate 20; and a metal layer 14 laminated on the laminate 20. Therefore, the metal-clad laminate comprises: the laminate according to this embodiment; and a metal layer laminated on at least one main surface of the laminate. It should be noted that... Figure 3 It means possessing Figure 1 A schematic cross-sectional view of an example of a metal foil-coated laminate 10 (the metal foil-coated laminate 30). Figure 4 It means possessing Figure 2 A schematic cross-sectional view of an example of a metal foil laminate 40 of the laminate 20 shown.

[0138] As the metal layer 14, examples include metal layers formed on the cured film by a method called semi-addition, as described above. Furthermore, as the metal layer 14, examples include metal foils, more specifically copper foils and aluminum foils, with copper foils being preferred. When the metal foil is thin, to improve operability, it can be a carrier-supported copper foil having a release layer and a carrier. The copper foil can contain copper; for example, it can be formed from copper or a copper alloy. Examples of copper alloys include, for instance, alloys containing at least one selected from the group consisting of nickel, phosphorus, tungsten, arsenic, molybdenum, chromium, cobalt, and zinc, and copper.

[0139] The thickness of the metal layer 14 varies depending on the performance requirements of the final wiring board and is not particularly limited. The thickness of the metal layer 14 can be appropriately set according to the desired purpose; for example, it is preferably 105 μm or less, more preferably 0.2 to 35 μm. Furthermore, the arithmetic mean roughness (Ra) of the metal layer 14 is preferably 2 μm or less, more preferably 0.1 to 1.5 μm. Furthermore, the ten-point average roughness (Rz) of the metal layer 14 is preferably 10 μm or less, more preferably 0.5 to 8 μm. The arithmetic mean roughness (Ra) and the ten-point average roughness (Rz) can be values ​​obtained by measurement according to the method of JIS B0601 (2001), and more specifically, they can be measured using a roughness tester or the like.

[0140] The metal layer 14 may also be a surface-treated metal foil. Regarding the surface-treated metal foil, both surfaces of the metal foil may be surface-treated, or only one surface of the metal foil may be surface-treated. Furthermore, if only one surface of the metal foil is surface-treated, it is preferable that the surface-treated surface is in contact with the laminate. Examples of surface treatments include silane coupling agent treatment, roughening treatment, heat resistance treatment, and rust prevention treatment. These surface treatments may be performed individually on the metal foil, or two or more surface treatments may be combined. Furthermore, the silane coupling agent used in the silane coupling agent treatment is not particularly limited; examples include silane coupling agents identical to those contained in the resin composition. As for the roughening treatment, heat resistance treatment, and rust prevention treatment, for example, general treatments may be performed on the metal foil, respectively.

[0141] As for the method of manufacturing the metal foil laminate, there is no particular limitation as long as the metal foil laminate can be manufactured. For example, as a method of manufacturing the metal foil laminate, a prepreg containing the first resin composition or a semi-cured product of the first resin composition is first heated to cure it. Then, a film containing the second resin composition or a semi-cured product of the second resin composition is overlapped on one side of the cured product's main surface, and a film containing the second resin composition or a semi-cured product of the second resin composition is overlapped on the other side of the cured product's main surface. The metal foil is then overlapped on each film. The cured prepreg with the overlapped film and metal foil is heated and pressurized to form a laminated unit. The metal foil laminate is thus obtained. Furthermore, when manufacturing the laminate, the metal foil laminate can be obtained even if a film with a metal foil is used as the film. Furthermore, a film containing a second resin composition or a semi-cured product of the first resin composition is overlapped on one main surface of a prepreg containing the first resin composition or a semi-cured product of the first resin composition, and a metal foil is overlapped thereon. On the other hand, a film containing a third resin composition or a semi-cured product of the third resin composition is overlapped on the other main surface of the prepreg, and a metal foil is overlapped thereon. The prepreg with the overlapping film and metal foil is heated and pressurized to form an integral laminate. The metal foil-coated laminate can also be obtained by this manufacturing method. Alternatively, a laminate is formed by overlapping a film containing a second resin composition or a semi-cured product of the second resin composition on one main surface of a cured product after the prepreg containing the first resin composition or a semi-cured product of the first resin composition has been cured, and a film containing a second resin composition or a semi-cured product of the second resin composition is overlapped on the other main surface of the cured product. The film of the laminate is cured, and a metal layer is then formed thereon by a method called a semi-addition process. The metal foil laminate can also be obtained using this semi-additive manufacturing method.

[0142] The laminate involved in this embodiment is a laminate in which warpage is suppressed. Therefore, since the metal foil laminate includes the laminate, it is a metal foil laminate in which warpage is suppressed.

[0143] [Wiring board]

[0144] like Figure 5 As shown, a wiring board 50 incorporating the laminate 10 according to an embodiment of the present invention includes: the laminate 10; and wiring 16 laminated on the laminate 10. Figure 5 As shown, the wiring 16 can be stacked on both sides of the laminate 10, or on one side of the laminate 10. Furthermore, the laminate of the wiring board is not limited to the type shown. Figure 1 The laminate 10 shown can be any laminate involved in this embodiment; for example, it can also be as follows: Figure 2 The layered body 20 shown. That is, as... Figure 6 As shown, the wiring board may also include: the laminate 20; and a wiring board 60 having wiring 16 laminated on the laminate 20. Therefore, the wiring board includes: the laminate according to this embodiment; and wiring disposed on at least one main surface of the laminate. The laminate is used as such... Figure 2 In the case of the stack-up 20 shown, the resulting wiring board is a multilayer wiring board. It should be noted that... Figure 5 It means possessing Figure 1 A schematic cross-sectional view of an example of the wiring board (wiring board 50) of the stack 10 shown. Figure 6 It means possessing Figure 2 A schematic cross-sectional view of an example of a wiring board (the wiring board 60) of the stack 20 shown.

[0145] Examples of wiring 16 include wiring formed by partially removing the metal layer 14.

[0146] The method for manufacturing the wiring board is not particularly limited as long as it can be manufactured. Examples of methods for manufacturing the wiring board include etching the metal layer on the surface of the metal-clad laminate to form wiring, thereby creating a wiring board with wiring forming a circuit on the surface of the laminate. In other words, the wiring board can be obtained by partially removing the metal layer on the surface of the metal-clad laminate to form a circuit. Furthermore, in addition to the methods described above, methods for forming the circuit include, for example, forming the circuit using a semi-additive process (SAP) or a modified semi-additive process (MSAP).

[0147] The laminate involved in this embodiment is a laminate in which warpage is suppressed. Therefore, since the wiring board has the laminate, it is a wiring board in which warpage is suppressed.

[0148] This specification discloses various implementation techniques as described above, and the main techniques therein are summarized below.

[0149] The first technical solution of the present invention relates to a laminate, comprising: a substrate having a first insulating layer; a second insulating layer laminated on a first main surface of the substrate; and a third insulating layer laminated on a second main surface of the substrate, wherein the thickness of the first insulating layer is 600 to 2000 μm, and the flexural modulus of the first insulating layer at 25°C is 25 GPa or more; the thicknesses of the second insulating layer and the third insulating layer are 5 to 70 μm, and the tensile storage modulus of the second insulating layer and the third insulating layer at 25°C are 0.5 to 5 GPa, respectively.

[0150] In the laminate of the second technical solution of the present invention, the absolute value of the difference between the coefficient of thermal expansion of the laminate at 50-260°C and the coefficient of thermal expansion of the first insulating layer at 50-260°C is 0-0.35ppm / °C.

[0151] In the laminated body of the third technical solution of the present invention, the first insulating layer comprises a fibrous substrate, while the second and third insulating layers do not comprise a fibrous substrate.

[0152] In the laminated body of any one of the first to third technical solutions of the present invention, the first insulating layer is a cured prepreg.

[0153] In the laminated body of any one of the first to fourth technical solutions of the present invention, the second insulating layer and the third insulating layer are respectively obtained by curing a film.

[0154] In the laminated body according to the sixth technical solution of the present invention, in any of the laminated bodies according to the first to fifth technical solutions of the present invention, the second insulating layer and the third insulating layer respectively contain cured resin compositions, the resin compositions containing curable resin and inorganic filler materials, and the content of inorganic filler materials is 70% by mass or less relative to the total amount of the resin composition excluding the inorganic filler materials.

[0155] The seventh technical solution of the present invention relates to a film for forming a second insulating layer and a third insulating layer in a laminate, the laminate comprising: a substrate having a first insulating layer; the second insulating layer being laminated on a first main surface of the substrate; and the third insulating layer being laminated on a second main surface of the substrate, wherein the thickness of the first insulating layer is 600 to 2000 μm and the flexural modulus at 25°C is 25 GPa or more, and the second insulating layer and the third insulating layer are layers obtained by curing the film, having a thickness of 5 to 70 μm and a tensile storage modulus at 25°C of 0.5 to 4 GPa.

[0156] In the membrane of the eighth technical solution of the present invention, the absolute value of the difference between the coefficient of thermal expansion of the laminate at 50 to 260°C and the coefficient of thermal expansion of the first insulating layer at 50 to 260°C is 0 to 0.35 ppm / °C.

[0157] According to the present invention, a laminate in which warpage is suppressed can be provided, and a membrane in which warpage is suppressed can be formed.

[0158] The present invention will be further described in detail below through embodiments; however, the scope of the present invention is not limited to these embodiments.

[0159] Example

[0160] [Examples 1-7 and Comparative Examples 1-3]

[0161] <First Insulation Layer>

[0162] The following products were used as the first insulating layer.

[0163] R-1515V: R-1515V manufactured by Panasonic Machinery Co., Ltd.

[0164] R-1515K: R-1515K manufactured by Panasonic Machinery Co., Ltd. (thickness: 800μm)

[0165] R-1515V with different thicknesses (400μm, 800μm, 1000μm and 1200μm) were prepared. In each example and comparative example, the products with the thicknesses shown in Table 1 were used.

[0166] (Flexural modulus)

[0167] The flexural modulus of the first insulating layer at 25°C was determined. Specifically, the determination was performed using the following method: First, a three-point bending test was conducted on the first insulating layer at 25°C. The flexural modulus (GPa) was calculated based on the resulting stress-strain curve. The results are shown in Table 1.

[0168] (Coefficient of thermal expansion: CTE)

[0169] The coefficient of thermal expansion of the first insulating layer was determined using the following method. The first insulating layer was used as a test piece, and the coefficient of thermal expansion was calculated using a 3D heated surface shape measuring device (Akrometrix "THERMOIRE PS200"). More specifically, the temperature was increased from 50°C at a rate of 20°C / min, and then decreased from 260°C back to 50°C at a rate of 15°C / min. This operation was repeated twice, and the coefficient of thermal expansion was calculated based on the strain data from 50°C to 260°C during the second heating. The results are shown in Table 1.

[0170] <Second and Third Insulation Layers>

[0171] The layers obtained as follows were used as the second and third insulating layers.

[0172] (Component A)

[0173] Modified PPE-1: A modified polyphenylene ether compound whose terminal hydroxyl groups are modified with methacrylamide groups [represented by the above formula (12), and Y in the above formula (12) is dimethylmethylene (represented by the above formula (9) and R in the above formula (9)] 33 and R 34 [A modified polyphenylene ether compound (containing methyl groups), SA9000 manufactured by SABIC Innovative Plastics, with a number-average molecular weight of Mn2300 and 2 terminal functional groups]

[0174] Tuftec H1041: Hydrogenated styrene (ethylene / butene) styrene block copolymer (Tuftec H1041 manufactured by Asahi Kasei Corporation)

[0175] TAIC: Triallyl isocyanurate (TAIC manufactured by Nippon Chemical Co., Ltd.)

[0176] PERBUTYL P: α,α'-Di(tert-butylperoxy)diisopropylbenzene (PBP) (PERBUTYL P manufactured by Nippon Yu Co., Ltd.)

[0177] Inorganic filler material-1: Spherical silica (SC2300-SVJ manufactured by Admatechs Company Limited)

[0178] 40 parts by weight of modified PPE-1, 40 parts by weight of Tuftec H1041, 20 parts by weight of TAIC, and 1 part by weight of PERBUTYL P were added to a mixed solvent of toluene and methyl ethyl ketone (MEK) (mass ratio approximately 1:1) and stirred for 60 minutes to achieve a solids concentration of 50% by weight. Then, 100 parts by weight of inorganic filler-1 were added to the resulting mixture and dispersed using a bead mill. This yielded the varnish-like resin composition (varnish) of composition A.

[0179] (Component B)

[0180] By changing the amount of inorganic filler-1 to 180 parts by mass, the same varnish as that involved in composition A was manufactured to obtain the varnish-like resin composition (varnish) involved in composition B.

[0181] (Composition C)

[0182] Modified PPE-2: A polyphenylene ether compound with a vinyl benzyl (ethylene benzyl) group at the end (OPE-2st 1200 manufactured by Mitsubishi Gas Chemical Co., Ltd.)

[0183] BMI4000: Bisphenol A type diphenyl ether bismaleimide (BMI4000 manufactured by Daiwa Chemical Industry Co., Ltd.)

[0184] BMI689: Dimer acid backbone bismaleimide (BMI689 manufactured by Designer Molecules Inc.)

[0185] Ricon181: Styrene-polybutadiene oligomer (Ricon181 manufactured by Cray Valley)

[0186] PQ-60: Diphenylphosphine oxide compound (PQ-60 manufactured by Jin Yi Chemical Co., Ltd.)

[0187] Inorganic filler material-2: Spherical silica (SC2500-SXJ manufactured by Yatuma Co., Ltd.)

[0188] 38 parts by weight of modified PPE-2, 32 parts by weight of BMI4000, 21 parts by weight of BMI689, 9 parts by weight of Ricon181, and 25 parts by weight of PQ-60 were added to a mixed solvent of toluene and methyl ethyl ketone (MEK) (mass ratio approximately 1:1) and stirred for 60 minutes to achieve a solids concentration of 50% by weight. Then, 115 parts by weight of inorganic filler-2 were added to the resulting mixture and dispersed using a bead mill. This yielded the varnish-like resin composition (varnish) of composition C.

[0189] The obtained varnishes were applied to the release film in such a way that the thickness after heating and drying was as shown in Table 1, and then heated and dried at 110°C for two minutes, thereby producing a film formed from the cured product of the second resin composition (the third composition).

[0190] It should be noted that in Comparative Example 3, the second and third insulating layers were not made of the aforementioned film, but were manufactured using prepreg (R-G540L manufactured by Panasonic Corporation).

[0191] (Extensional storage modulus)

[0192] The tensile storage modulus of the cured film or prepreg used to manufacture the second insulating layer (the third insulating layer) was determined at 25°C. Specifically, the determination was performed by the following method: First, the cured material was cut into 10mm × 40mm pieces. These cut films were used as test pieces and mounted on a dynamic viscoelasticity measuring device (DMS6100 manufactured by Seiko Instruments Inc.). The tensile method was used, with a strain amplitude of 10μm, a frequency of 10Hz (sine wave), and a heating rate of 10°C / min, and the test was conducted in the range from 20°C to 260°C. The tensile storage modulus (GPa) at 25°C was measured. The results are shown in Table 1.

[0193] (Coefficient of thermal expansion: CTE)

[0194] The coefficient of thermal expansion of the cured film or prepreg used to manufacture the second insulating layer (the third insulating layer) was determined by the following measurement method.

[0195] Using the test piece described in the method for determining tensile storage modulus, the coefficient of thermal expansion (CTE: ppm / °C) in the planar direction (tensile direction, or Y-axis direction in the case of prepreg) of the test piece was determined according to IPC TM-650 and by the TMA (Thermo-mechanical Analysis) method. Specifically, the measurement was performed in compression mode using a TMA apparatus (TMA6000 manufactured by Seiko Electronics Nanotechnology Co., Ltd.). To eliminate the influence of thermal strain on the test piece, the test piece was stretched along the Y-axis with a 10g load, and then heated from 30°C to 320°C at a heating rate of 10°C / min, and then cooled to room temperature. Then, the test piece was stretched along the Y-axis with a 10g load, and then heated from 30°C to 320°C at a heating rate of 10°C / min. During this heating, a temperature displacement diagram was obtained. Then, based on the temperature displacement diagram obtained at this time, the average coefficient of thermal expansion from 50 to 260°C was calculated. The results are shown in Table 1.

[0196] <Layered Body>

[0197] The film or the prepreg used to manufacture the second insulating layer (the third insulating layer) is overlapped on both sides of the first insulating layer. Copper foil with a thickness of 12 μm is then overlapped vertically and used as a pressing body. The film is heated to 220°C at a heating rate of 3°C / min and then heated and pressurized at 220°C for 120 minutes and 3 MPa. As a result, the film or the prepreg is cured while in contact with the first insulating layer, thus obtaining a laminate.

[0198] The laminate obtained by etching the copper foil of the laminate manufactured as described above was evaluated by the method shown below.

[0199] [Coefficient of thermal expansion: CTE]

[0200] The coefficient of thermal expansion of the laminate was determined using the same method as that used for the first insulating layer. The results are shown in Table 1.

[0201] [Warpage (difference in thermal expansion coefficient: CTE difference)]

[0202] The value of subtracting the thermal expansion coefficient of the first insulating layer from the thermal expansion coefficient of the laminate was calculated. The results are shown in Table 1. The smaller the absolute value of the difference between the thermal expansion coefficient of the laminate and the thermal expansion coefficient of the first insulating layer, the more warpage is suppressed. Specifically, it was confirmed that if the value of subtracting the thermal expansion coefficient of the first insulating layer from the thermal expansion coefficient of the laminate is -0.35 to 0.35 ppm / ℃ (i.e., the absolute value of the difference between the thermal expansion coefficient of the laminate and the thermal expansion coefficient of the first insulating layer is 0 to 0.35 ppm / ℃), it is considered that the difference in thermal expansion coefficients can sufficiently suppress the warpage of the laminate.

[0203]

[0204] According to Table 1, in the case where a second insulating layer and a third insulating layer with a thickness of 5 to 70 μm and a tensile storage modulus of 0.5 to 5 GPa at 25°C are stacked on each surface of a first insulating layer with a thickness of 600 to 2000 μm and a flexural modulus of 25 GPa or more at 25°C (Examples 1 to 7), unlike the case without this configuration (Comparative Examples 1 to 3), the absolute value of the difference between the coefficient of thermal expansion of the laminate and the coefficient of thermal expansion of the first insulating layer is 0 to 0.35 ppm / °C. Therefore, it can be seen that the laminates involved in Examples 1 to 7 can sufficiently suppress warping.

[0205] This application is based on Japanese Patent Application No. 2023-170289, filed on September 29, 2023, the contents of which are incorporated herein by reference.

[0206] To illustrate the invention, the present invention has been appropriately and sufficiently described above through embodiments. However, it should be recognized that those skilled in the art can readily make changes and / or modifications to the above embodiments. Therefore, any changes or modifications implemented by those skilled in the art that do not depart from the scope of protection of the claims set forth in the claims can be interpreted as being included within the scope of protection of the claims.

[0207] Industrial availability

[0208] According to the present invention, a laminate in which warpage is suppressed can be provided, and a membrane in which warpage is suppressed can be formed.

Claims

1. A laminated body, characterized in that... include: The substrate has a first insulating layer; A second insulating layer is laminated on the first main surface side of the substrate; as well as A third insulating layer is laminated on the second main surface side of the substrate, wherein... The thickness of the first insulating layer is 600–2000 μm, and the flexural modulus of the first insulating layer at 25°C is greater than 25 GPa. The thicknesses of the second insulating layer and the third insulating layer are 5 to 70 μm, and the tensile storage modulus of the second insulating layer and the third insulating layer at 25°C are 0.5 to 5 GPa, respectively.

2. The laminated body according to claim 1, characterized in that, The absolute value of the difference between the coefficient of thermal expansion of the laminate at 50–260°C and the coefficient of thermal expansion of the first insulating layer at 50–260°C is 0–0.35 ppm / °C.

3. The laminated body according to claim 1, characterized in that, The first insulating layer comprises a fibrous substrate. The second and third insulating layers do not contain fibrous substrates.

4. The laminated body according to claim 1, characterized in that, The first insulating layer is a cured prepreg.

5. The laminated body according to claim 1, characterized in that, The second insulating layer and the third insulating layer are respectively cured products of the film.

6. The laminated body according to claim 1, characterized in that, The second insulating layer and the third insulating layer each comprise a cured resin composition, the resin composition containing a curable resin and an inorganic filler, wherein the content of the inorganic filler is 70% by mass or less relative to the total amount of the resin composition excluding the inorganic filler.

7. A membrane, characterized in that, The laminate includes a second insulating layer and a third insulating layer for forming a laminate, the laminate comprising: a substrate having a first insulating layer; a second insulating layer laminated on a first main surface of the substrate; and a third insulating layer laminated on a second main surface of the substrate, wherein... The thickness of the first insulating layer is 600–2000 μm, and its flexural modulus at 25°C is greater than 25 GPa. The second insulating layer and the third insulating layer are obtained by curing the film, with a thickness of 5 to 70 μm and a tensile storage modulus of 0.5 to 4 GPa at 25°C.

8. The membrane according to claim 7, characterized in that, The absolute value of the difference between the coefficient of thermal expansion of the laminate at 50–260°C and the coefficient of thermal expansion of the first insulating layer at 50–260°C is 0–0.35 ppm / °C.

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