Resin substrates, metal-clad laminates, and wiring boards

Abstract

A resin substrate comprising a glass cloth woven from glass yarn having a Si content in the range of 95% to 100% by mass in terms of SiO2, and a resin composition, The above glass cloth has a yarn width variation coefficient calculated using the formula: Yarn width variation coefficient = Yarn width standard deviation [μm] / Yarn width [μm], where the value is within the range of 0.20 or less in both the warp and weft directions. A resin substrate having a loss tangent (tanδ) of 0.34 or less at 200°C.

Description

[Technical Field]

[0001] This disclosure relates to resin substrates, metal-clad laminates, and wiring boards, etc. [Background technology]

[0002] Currently, information terminals such as smartphones are becoming more high-performance, and high-speed communication, exemplified by 5G communication, is progressing. Against this backdrop, in particular for printed circuit boards used in high-speed communication, there is a demand not only for improved heat resistance, which has been required since before, but also for further improvement in the dielectric properties of the insulating material (for example, lower dielectric loss tangent). Similarly, improvements in dielectric properties are desired for prepregs used as insulating materials in printed circuit boards, the glass cloth contained in the prepregs, and the glass threads that make up the glass cloth.

[0003] Patent documents 1 and 2 describe constructing insulating materials using a prepreg in which a low-dielectric resin is impregnated into glass cloth as a resin composition, with the aim of reducing the dielectric strength of the insulating material. Patent documents 1 and 2 also describe that polyphenylene ether modified with vinyl groups or methacryloyl groups is advantageous for low dielectric properties and heat resistance, and that this modified polyphenylene ether is used as a resin composition.

[0004] Patent Document 3 describes that the dielectric properties of metal-clad laminates and wiring boards can be improved by using glass cloth with a silicon dioxide (SiO2) content of 96.0% to 100.0% by mass.

[0005] Incidentally, in addition to dielectric properties, drillability is required for metal-clad laminates. Various methods are known to improve the drill wear resistance during the drilling process of metal-clad laminates. For example, in Patent Document 4, by setting the SiO2 content of the glass cloth to 70% or less, drill wear during the drilling process of printed wiring boards is suppressed. In addition, Patent Document 5 describes a metal-clad laminate with less drill wear during drill cutting by using a resin composition having a specific molecular structure. Furthermore, Patent Document 6 describes a laminate with less drill wear during drilling by reducing the particle size of the inorganic filler. In addition, Patent Document 7 describes a method of greatly improving the drill wear resistance during the drilling process of laminates by using molybdenum compound particles with high lubricity as the inorganic filler.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Summary of the Invention

Problems to be Solved by the Invention

[0007] Conventional resin substrates, such as those described in Patent Documents 1 and 2, do not take into consideration the use of low-dielectric glass cloth, leaving room for further improvement of dielectric properties. In this regard, Patent Document 3 describes how the dielectric properties of prepregs and printed circuit boards can be improved by using glass cloth made of glass filaments with a high SiO2 content. However, as described in Patent Document 4, increasing the SiO2 content leads to increased drill wear during drilling of printed circuit boards, reducing drilling efficiency and thus hindering the manufacturing of printed circuit boards. To improve the dielectric properties of printed circuit boards, there is a strong need for a new method to improve drill wear resistance even when using glass cloth with an SiO2 content of 95-100% by mass. Patent Document 5 discloses a laminate with reduced drill wear by using a resin composition having a specific molecular structure. However, it does not mention why the resin composition having a specific molecular structure improves drill wear resistance, and it was not clarified what kind of molecular structure contributes to the drill wear resistance of the laminate. Patent document 6 discloses that drill wear can be suppressed by making the average particle size of the inorganic filler 3.0 μm or less. However, using an inorganic filler with a small average particle size tends to increase the viscosity of the varnish, which can easily lead to a decrease in the productivity of the prepreg. Patent Document 7 discloses that by using molybdenum compound particles supported or coated with a molybdenum compound as an inorganic filler, the molybdenum compound functions as a lubricant and can suppress drill wear. However, molybdenum compounds generally have high conductivity, and it is thought that the dielectric loss tangent of the resin substrate increases as the content increases. Furthermore, these patent documents focus on the composition, structure, and particle size of the resin and inorganic filler in the resin composition, and do not describe the physical properties of the resin substrate that affect the drill wear resistance.

[0008] This disclosure aims to provide resin substrates, metal-clad laminates, and wiring boards, etc., that contain glass cloth with a high SiO2 content of 95 to 100% by mass, and that can suppress drill wear during drilling. [Means for solving the problem]

[0009] Some aspects of this disclosure are illustrated in the following items [1] to

[30] . [1] A resin substrate comprising a glass cloth woven from glass yarn having a Si content in the range of 95% to 100% by mass in terms of SiO2, and a resin composition, The aforementioned glass cloth has a yarn width variation coefficient calculated using the formula: yarn width variation coefficient = yarn width standard deviation [μm] / yarn width [μm], where the value is within the range of 0.20 or less in both the warp and weft directions. A resin substrate having a loss tangent (tanδ) of 0.34 or less at 200°C. [2] The resin substrate according to [1], wherein the loss tangent (tanδ) at 200°C is in the range of 0.26 or less. [3] The resin substrate according to [1], wherein the loss tangent (tanδ) at 200°C is in the range of 0.20 or less. [4] The resin substrate according to [1], wherein the loss tangent (tanδ) at 200°C is in the range of 0.11 or less. [5] A resin substrate according to any one of [1] to [4], wherein the tensile strength per unit thickness of the glass cloth is in the range of 0.8 N / 25 mm / μm or more in both the warp and weft directions. [6] A resin substrate according to any one of [1] to [4], wherein the tensile strength per unit thickness of the glass cloth is in the range of 1.0 N / 25 mm / μm or more in both the warp and weft directions. [7] A resin substrate according to any one of [1] to [6], wherein the dielectric loss tangent of the glass cloth at 10 GHz is in the range of 0.0015 or less. [8] A resin substrate according to any one of [1] to [6], wherein the dielectric loss tangent of the glass cloth at 10 GHz is in the range of 0.0008 or less. [9] A resin substrate according to any one of [1] to [6], wherein the dielectric loss tangent of the glass cloth at 10 GHz is in the range of 0.0004 or less.

[10] A resin substrate according to any one of [1] to [9], wherein the dielectric loss tangent of the resin composition at 10 GHz is in the range of 0.00045 or less.

[11] A resin substrate according to any one of [1] to [9], wherein the dielectric loss tangent of the resin composition at 10 GHz is in the range of 0.0035 or less.

[12] A resin substrate according to any one of [1] to [9], wherein the dielectric loss tangent of the resin composition at 10 GHz is in the range of 0.0030 or less.

[13] A resin substrate according to any one of [1] to [9], wherein the dielectric loss tangent of the resin composition at 10 GHz is in the range of 0.0025 or less.

[14] The aforementioned glass cloth has an aperture ratio of 15.0% or less. The aforementioned aperture ratio is given by the following formula: A resin substrate as described in any of [1] to

[13] , calculated by the following formula: Open area [%] = ((25400 / warp density [threads / inch] - warp width [μm]) × (25400 / weft density [threads / inch] - weft width [μm]) × 100) / ((25400 / warp density [threads / inch]) × (25400 / weft density [threads / inch])).

[15] The resin substrate according to

[14] , wherein the aperture ratio of the glass cloth is in the range of 1.5% to 10.0%.

[16] The resin substrate according to

[14] , wherein the aperture ratio of the glass cloth is in the range of 2.0% to 8.0%.

[17] A resin substrate according to any one of [1] to

[16] , wherein the resin composition comprises at least one resin selected from epoxy resins, radical polymerization curing resins, maleimidotriazine resins, thermosetting polyimide resins, bismaleimide resins, benzoxazine resins, cyclopentadiene-styrene copolymer resins, polyphenylene ethers, modified polyphenylene ethers, polyphenylene sulfides, polysulfones, polyethersulfones, polyarylates, aromatic polyamides, polyether ketones, polyether ether ketones, thermoplastic polyimides, insoluble polyimides, polyamide imides, cycloolefin resins, cyanate resins, and fluororesins.

[18] The resin composition comprises an inorganic filler and is a resin substrate according to any one of [1] to

[17] .

[19] A resin substrate according to any of [1] to

[18] , wherein the glass transition temperature is in the range of 50°C or higher.

[20] A resin substrate according to any one of [1] to

[19] , wherein the volume fraction of the glass cloth in the resin substrate is in the range of 10% or more and 70% or less. [twenty one] A resin substrate according to any one of [1] to

[20] , wherein the number of layers of the glass cloth is 1 or more and 10 or less. [twenty two] A resin substrate according to any one of [1] to

[21] , wherein the coefficient of variation of the warp and weft thread widths of the glass cloth are in the range of 0.05 or more and 0.18 or less. [twenty three] A resin substrate according to any one of [1] to

[21] , wherein the coefficient of variation of the warp and weft thread widths of the glass cloth is in the range of 0.05 or more and 0.15 or less. [twenty four] A resin substrate according to any one of [1] to

[21] , wherein the coefficient of variation of the warp and weft thread widths of the glass cloth is in the range of 0.05 or more and 0.12 or less. [twenty five] A metal-clad laminate comprising a resin substrate as described in any of [1] to

[24] , wherein metal foil is provided on one or both sides of the surface layer of the resin substrate.

[26] A wiring board comprising a resin substrate as described in any of [1] to

[24] and a wiring pattern for transmitting and receiving electrical signals.

[27] An integrated circuit including a metal-clad laminate as described in

[25] .

[28] An integrated circuit, including the wiring board described in

[26] .

[29] Electronic equipment including the integrated circuit described in

[27] .

[30] Electronic equipment including the integrated circuit described in

[28] . [Effects of the Invention]

[0010] According to this disclosure, it is possible to provide resin substrates, metal-clad laminates, and wiring boards, etc., that have excellent drill wear resistance and dielectric properties. [Modes for carrying out the invention]

[0011] The embodiments of this disclosure will be described below, but this disclosure is not limited thereto, and various modifications are possible without departing from its essence.

[0012] In this disclosure, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the lower and upper limits, respectively. Furthermore, in numerical ranges described in stages, the upper or lower limit indicated in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Moreover, the upper or lower limit indicated in one numerical range may be replaced with the values ​​shown in the examples. The term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, as long as the function of the process is achieved.

[0013] 《Overall Structure》 The resin substrate of this disclosure is a resin substrate comprising a glass cloth (hereinafter referred to as "glass cloth of this disclosure") made by weaving glass yarn having a Si content in the range of 95% to 100% by mass in terms of SiO2, and a resin composition. The glass cloth of this disclosure has a yarn width variation coefficient calculated using the formula: yarn width variation coefficient = yarn width standard deviation [μm] / yarn width [μm], which is in the range of 0.20 or less in both the warp and weft directions. Furthermore, the loss tangent (tanδ) of the resin substrate of this disclosure at 200°C is in the range of 0.34 or less.

[0014] As a result of their investigation, the inventors have discovered for the first time that the viscoelastic properties of the resin substrate, which had not been previously considered, significantly affect the wear resistance of the drill. Specifically, they found that while the temperature of the laminate processing area rises to about 200°C during drilling, a lower loss tangent (tanδ) of the laminate during processing is effective in suppressing wear of the diamond-coated, high-heat-resistant drill. Furthermore, the inventors have found that by uniformly opening the quartz glass cloth and adjusting the coefficient of variation of the fiber width of the glass cloth to 0.20 or less, the number of locations where bundles of quartz glass fibers with high hardness are localized in the direction of drilling is reduced, thereby further improving the drill wear resistance of the metal-clad laminate. By using a resin substrate containing glass cloth with a thread width variation coefficient of 0.20 or less and a loss tangent (tanδ) of 0.34 or less at a temperature (in one embodiment, cutting temperature) of 200°C, it became possible to suppress wear on the outer circumference of a drill of a metal-clad laminate containing glass cloth with an SiO2 content of 95% by mass or more.

[0015] [Glass thread] The glass yarn constituting the glass cloth of this disclosure can be obtained using quartz glass as a raw material. Specifically, the Si content is in the range of 95% to 100% by mass in terms of SiO2. From the viewpoint of the dielectric properties of the glass yarn, a Si content of 99.0% to 100% by mass is more preferable, 99.5% to 100% by mass is even more preferable, and 99.9% to 100% by mass is particularly preferable. By using glass yarn with the above Si content, it is possible to reduce the dielectric loss tangent of the glass cloth. Because quartz glass has a higher SiO2 content and therefore higher hardness compared to other types of glass, it was found that using glass cloth made from quartz glass yarn could further improve the drill wear resistance during drilling of metal-clad laminates.

[0016] The average single filament diameter of the glass filaments constituting the glass yarn is 3.0 μm to 9.0 μm. More preferably, it is 4.0 μm to 9.0 μm or 5.0 μm to 9.0 μm, even more preferably 4.5 μm to 8.5 μm or 5.5 μm to 8.5 μm, even more preferably 5.5 μm to 8.2 μm or 5.8 μm to 8.2 μm, and particularly preferably 6.0 μm to 8.0 μm. If the average single filament diameter falls below 3.0 μm, the filaments become prone to breakage, and the fluff quality of the glass cloth deteriorates.

[0017] The average number of glass filaments constituting the glass thread is preferably in the range of 20 to 200, more preferably 30 to 200, even more preferably 35 to 180, and particularly preferably 40 to 160.

[0018] [Glass cloth overall composition] [Weave structure of glass cloth, etc.] Glass cloth is constructed using glass threads (for example, glass threads made of multiple glass filaments) as warp and weft threads. Examples of weaving structures for glass cloth include plain weave, twill weave, satin weave, and twill weave. Among these, the plain weave structure is preferred.

[0019] The weaving density of the warp and weft threads constituting the glass cloth is preferably 10 threads / inch to 120 threads / inch (=10 to 120 threads / 25.4 mm), and more preferably 40 threads / inch to 100 threads / inch.

[0020] The basis weight (mass) of the glass cloth is 8 g / m². 2 ~250g / m 2 A range of 100 g / m² is preferred, and more preferably 100 g / m² from the viewpoint of easily controlling the opening of the glass cloth fibers.2 The following, and more preferably 80 g / m² 2 The following is preferred: 50 g / m² 2 The following applies: If the basis weight of the glass cloth is within the above range, it is easier to adjust the coefficient of variation in the fiber width and the opening ratio of the glass cloth to a predetermined range, and the effect of improving the wear resistance of the drill is easily obtained. The basis weight of the glass cloth is measured by the method described in the example.

[0021] [Width of glass cloth threads] The warp and weft thread widths of the glass cloth are preferably in the range of 100 to 500 μm, more preferably 120 to 480 μm, and even more preferably 150 to 450 μm. If the thread width is within the above range, it is easier to adjust the coefficient of variation of the glass cloth's thread width and the opening ratio to a predetermined range, and the effect of improving drill wear resistance is easily obtained. The warp and weft thread widths of the glass cloth are measured by the method described in the examples.

[0022] [Opening ratio of glass cloth] The inventors have found that the more the glass cloth contained in the metal-clad laminate is opened, the fewer locations there are where bundles of quartz glass fibers with high hardness are localized in the direction of drilling, and the easier it is to improve the wear resistance of the drill. Furthermore, the inventors have found that in order to evaluate whether the glass cloth is opened sufficiently, We found that the opening ratio of glass cloth calculated using the formula: Opening ratio [%] = ((25400 / warp thread density [threads / inch] - warp thread width [μm]) × (25400 / weft thread density [threads / inch] - weft thread width [μm]) × 100) / ((25400 / warp thread density [threads / inch]) × (25400 / weft thread density [threads / inch])) is effective.

[0023] The aperture ratio can be adjusted by opening the fibers of the glass cloth, and glass cloth that has been sufficiently opened tends to have a small aperture ratio. From the viewpoint of improving drill wear resistance, the opening ratio of the glass cloth may be 0.5% or more and 15.0% or less, preferably 1% or more and 10% or less, more preferably 1.5% or more and 10.0% or less, and even more preferably 2.0% or more and 8.0% or less. From the viewpoint of improving drill wear resistance, the open area ratio of the glass cloth may be 15.0% or less, preferably in the range of 10% or less, and more preferably in the range of 8% or less. If the open area ratio of the glass cloth is within the above range, the glass cloth is sufficiently opened, there are fewer localized areas of hard quartz glass fiber bundles, and drill wear resistance is easily improved. Furthermore, it is known that because quartz glass has a higher hardness than other types of glass, conventional fiber opening treatments do not sufficiently and uniformly open the fibers. As a method for reducing the aperture ratio of the quartz glass cloth, it is preferable to perform ultrasonic and high-pressure water spraying as a fiber-opening treatment, as described below. Performing ultrasonic and high-pressure water spraying as a fiber-opening treatment makes it easier to sufficiently open the glass cloth fibers. Although not particularly limited, the aperture ratio of the glass cloth in this disclosure should be 0.5% or more, preferably 1.0% or more, more preferably 1.5% or more, and even more preferably 2.0% or more.

[0024] [Standard deviation of fiberglass yarn width] The standard deviation of the fiberglass cloth's yarn width is preferably in the range of 80 μm or less in both the warp and weft directions, more preferably 70 μm or less, even more preferably 60 μm or less, even more preferably 50 μm or less, and particularly preferably 40 μm or less. If the standard deviation of the yarn width is within the above range, it is easier to adjust the coefficient of variation of the fiberglass cloth's yarn width to a predetermined range, and the effect of improving drill wear resistance is easily obtained. Although not particularly limited, the standard deviation of the fiberglass cloth's yarn width may be 1 μm or more in both the warp and weft directions. The standard deviation of fiberglass yarn width can be controlled by the ultrasonic output and spray water pressure during the fiber opening process. The standard deviation of the yarn width of the glass cloth in this disclosure is measured by the method described in the examples.

[0025] [Coefficient of variation in fiberglass yarn width] In one embodiment of the glass cloth described herein, the coefficient of variation of the fiber width of the glass cloth is in the range of 0.20 or less in both the warp and weft directions. The inventors have found that the smaller the coefficient of variation of the fiber width of the warp and weft threads of the glass cloth contained in the metal-clad laminate, the fewer locations there are where bundles of quartz glass fibers with high hardness are localized in the direction of drilling, and the easier it is to improve the wear resistance of the drill. From the viewpoint of easily obtaining the effects of this disclosure, the coefficient of variation of the warp and weft yarn width of the glass cloth is preferably in the range of 0.05 to 0.18, more preferably in the range of 0.05 to 0.15, even more preferably in the range of 0.05 to 0.12, even more preferably in the range of 0.05 to 0.11, and particularly preferably in the range of 0.05 to 0.10. From the viewpoint of easily obtaining the effects of this disclosure, the coefficient of variation of the warp and weft threads of the glass cloth is preferably in the range of 0.18 or less, more preferably in the range of 0.15 or less, even more preferably in the range of 0.13 or less, even more preferably in the range of 0.12 or less, particularly preferably in the range of 0.11 or less, and most preferably in the range of 0.10 or less. Although not particularly limited, the coefficient of variation of the warp and weft threads of the glass cloth of this disclosure may be 0.01 or more, and preferably 0.05 or more. The coefficient of variation of the yarn width of the glass cloth in this disclosure is measured by the method described in the examples.

[0026] [Dielectric loss tangent of glass cloth] The dielectric loss tangent of the glass cloth at 10 GHz is preferably 0.0015 or less, preferably 0.0009 or less, more preferably 0.0008 or less, even more preferably 0.0007 or less, even more preferably 0.0006 or less, particularly preferably 0.0005 or less, and most preferably 0.0004 or less. If the dielectric loss tangent of glass cloth at 10 GHz is 0.0015 or less, it is easier to improve the dielectric properties of printed circuit boards. If the dielectric loss tangent of glass cloth at 10 GHz is 0.0004 or less, 0.00035 or less, 0.00033 or less, or 0.0003 or less, it becomes even easier to improve the dielectric properties of printed circuit boards. While not particularly limited, the dielectric loss tangent of the glass cloth in this disclosure at 10 GHz should be 0.00005 or greater. The dielectric loss tangent of the glass cloth in this disclosure is measured by the method described in the examples.

[0027] [Thickness of glass cloth] The thickness of the glass cloth is preferably 10 μm or more and 100 μm or less. From the viewpoint of easy control of opening the glass cloth fibers, the thickness of the glass cloth is preferably 80 μm or less, more preferably 60 μm or less, and particularly preferably 50 μm or less. Furthermore, from the viewpoint of excellent handling during transport of the glass cloth, the thickness of the glass cloth is preferably 15 μm or more, more preferably 20 μm or more, and particularly preferably 30 μm or more. The thickness of the glass cloth is measured by the method described in the examples.

[0028] [Tensile strength of glass cloth in the warp and weft directions] The tensile strength in the warp and weft directions of the glass cloth according to this disclosure is preferably 16 N / 25 mm or more, more preferably 18 N / 25 mm or more, and even more preferably 20 N / 25 mm or more. If the tensile strength in the warp and weft directions of the glass cloth is 16 N / 25 mm or more, it is possible to prevent the glass cloth from breaking during the manufacturing process of the glass cloth and prepreg, and improve the yield. Furthermore, if the tensile strength of the glass cloth in the warp and weft directions is 16 N / 25 mm or more, crystallization due to devitrification during the heating and de-oiling process is sufficiently suppressed, and the increase in glass hardness is suppressed by reducing the amount of crystalline components in the glass, thus suppressing drill wear. Although not particularly limited, the tensile strength of the glass cloth in the warp and weft directions of the glass cloth in this disclosure may be 400 N / 25 mm or less. The tensile strength in the warp and weft directions of the glass cloth of this disclosure shall be measured by the method described in the examples. The tensile strength of the glass cloth in the warp and weft directions can be controlled by the amount of Na ions and / or Mg ions adhering to the glass cloth surface during pre-heating and oil removal washing.

[0029] [Tensile strength per unit thickness of glass cloth] The tensile strength per unit thickness of the glass cloth of this disclosure is preferably 0.8 N / 25 mm / μm or more, more preferably 1.0 N / 25 mm / μm or more, even more preferably 1.2 N / 25 mm / μm or more, even more preferably 1.4 N / 25 mm / μm or more, and particularly preferably 1.6 N / 25 mm / μm or more, in both the warp and weft directions. If this value is 0.8 N / 25 mm / μm or more, it is possible to prevent the glass cloth from cutting during the manufacturing process of the glass cloth and prepreg, and improve the yield. The tensile strength per unit thickness of the glass cloth may be 6.0 N / 25 mm / μm or less, 5.0 N / 25 mm / μm or less, 4.0 N / 25 mm / μm or less, or 3.0 N / 25 mm / μm or less. The tensile strength per unit thickness of the glass cloth in this disclosure is measured by the method described in the examples.

[0030] [Method for evaluating the dielectric loss tangent of glass cloth and resin substrates] The dielectric properties of the glass cloth and the resin substrate of the present disclosure can be measured using the resonance method. A preferred measuring instrument using the resonance method is a split cylinder resonator. According to the resonance method, it is possible to measure simply and accurately compared to the conventional measuring method of manufacturing a printed wiring board as a measurement sample and evaluating the dielectric properties. Although not limited to theory, this is because the resonance method is suitable for evaluating low-loss materials in the high-frequency region.

[0031] The measurable range of the measuring instrument for the dielectric properties of the glass cloth and the resin substrate applicable to a printed wiring board, particularly a printed wiring board for high-speed communication, is preferably within a suitable range for both the frequency dielectric constant (Dk) and the dielectric tangent (Df). For example, Dk is preferably 1.1 or more and 50 or less, more preferably 1.51 or more and 10 or less, and still more preferably 2.0 or more and 5 or less. Also, Df may be greater than 0, preferably 1.0×10 -6 above 1.0×10 -1 below, more preferably 1.0×10 -5 above 5.0×10 -2 below, still more preferably 5.0×10 -5 above 1.0×10 -2 below.

[0032] The measurable frequency of the measuring instrument is preferably 10 GHz or more. If the frequency is 10 GHz or more, it is possible to evaluate the characteristics in the frequency band region assumed when actually used as the glass cloth of a printed wiring board for high-speed communication.

[0033] The lower limit of the measurement area is preferably 10 mm 2 or more, more preferably 15 mm 2 or more, still more preferably 20 mm 2 or more. Also, the upper limit of the measurement area may be 45 m 2 or less.

[0034] The measurable sample thickness is preferably 3 μm to 300 μm, more preferably 5 μm to 200 μm, and even more preferably 7 μm to 150 μm.

[0035] [Overall composition of resin composition] The matrix resin used in the resin composition can be either a thermosetting resin or a thermoplastic resin. If possible, both may be used in combination, or other resins may be further included.

[0036] Examples of thermosetting resins include epoxy resins (e.g., bisphenol A novolac type epoxy resin, brominated bisphenol A type epoxy resin, and bisphenol A type epoxy resin), radical polymerization curing resins, maleimidotriazine resins, thermosetting polyimide resins, bismaleimide resins, benzoxazine resins, and cyclopentadiene-styrene copolymer resins. Epoxy resins can be obtained by reacting compounds without a catalyst, or by adding a catalyst with catalytic activity, such as an imidazole compound, a tertiary amine compound, a urea compound, or a phosphorus compound, to the reaction. Furthermore, when obtaining radical polymerization curing resins, a thermal decomposition catalyst or a photodecomposition catalyst can be used as a reaction initiator.

[0037] Examples of thermoplastic resins include polyphenylene ether (PPE), modified polyphenylene ether, polyphenylene sulfide, polysulfone, polyethersulfone, polyarylate, aromatic polyamide, polyether ketone, polyether ether ketone, thermoplastic polyimide, insoluble polyimide, polyamide-imide, cycloolefin resin, cyanate resin, bisphenol A novolac resin, and fluororesin. For insulating materials of printed circuit boards for high-speed communication, polyphenylene ether or modified polyphenylene ether with high radical reactivity is preferred. The resin composition of this disclosure can use a combination of thermosetting resin and thermoplastic resin.

[0038] The resin compositions of this disclosure preferably include at least one resin selected from epoxy resins, radical polymerization-curing resins, maleimidotriazine resins, thermosetting polyimide resins, bismaleimide resins, benzoxazine resins, cyclopentadiene-styrene copolymer resins, polyphenylene ethers, modified polyphenylene ethers, polyphenylene sulfides, polysulfones, polyethersulfones, polyarylates, aromatic polyamides, polyether ketones, polyetherether ketones, thermoplastic polyimides, insoluble polyimides, polyamideimides, cycloolefin resins, cyanate resins, and fluororesins.

[0039] When the matrix resin used in printed circuit boards for high-speed communication has vinyl groups or methacrylic groups, it is preferable to use a silane coupling agent that has relatively high hydrophobicity and functional groups that are involved in radical reactions, such as methacrylic groups.

[0040] Furthermore, the resin composition may further contain inorganic fillers. Inorganic fillers are preferably used in combination with the thermosetting resin, and examples include aluminum hydroxide, zirconium oxide, calcium carbonate, alumina, mica, aluminum carbonate, magnesium silicate, aluminum silicate, silica, talc, glass short fibers, aluminum borate, and silicon carbide. Inorganic fillers may be used alone or in combination of two or more types. From the viewpoint of suppressing drill wear, the content of inorganic fillers relative to the total solid content in the resin composition of this disclosure is preferably 80% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less. From the viewpoint of improving the strength of the resin substrate, the content of inorganic fillers relative to the total solid content in the resin composition of this disclosure is preferably 1% by mass or more, more preferably 2% by mass or more, and particularly preferably 3% by mass or more.

[0041] The resin composition may further contain an elastomer. Examples of elastomers include block copolymers of vinyl aromatic compounds and olefin-based alkene compounds, hydrogenated versions thereof (e.g., hydrogenated styrene-based thermoplastic elastomer: trade name: ToughTec H1041, manufactured by Asahi Kasei Corporation), and homopolymers of vinyl aromatic compounds. The elastomer may be used alone or in combination of two or more types.

[0042] The elastomer content in the resin composition is not particularly limited, as long as the loss tangent of the resin substrate is within a predetermined range. For example, in the case of a resin composition containing modified polyphenylene ether, it is preferable that the elastomer content relative to the modified polyphenylene ether content is 90% by mass or less, as this makes it easier to control the loss tangent of this disclosure within a predetermined range. From the viewpoint of controlling the loss tangent of the resin substrate of this disclosure within a predetermined range, the content of the elastomer relative to the content of the modified polyphenylene ether in the resin composition containing the modified polyphenylene ether is more preferably 50% by mass or less, even more preferably 30% by mass or less, even more preferably 20% by mass or less, particularly preferably 10% by mass or less, extremely preferably 5% by mass or less, and most preferably 1% by mass or less.

[0043] The resin composition may further contain a crosslinking agent. Examples of crosslinking agents include acrylamide-based crosslinking agents, vinyl sulfone-based crosslinking agents, allyl-based crosslinking agents (e.g., triallyl isocyanurate), and other radical polymerizable compounds, as well as epoxy crosslinking agents. The crosslinking agent may be used alone or in combination of two or more types.

[0044] The amount of crosslinking agent in the resin composition is not particularly limited, as long as the loss tangent of the resin substrate is within a predetermined range. For example, in the case of a resin composition containing modified polyphenylene ether, it is preferable that the amount of crosslinking agent relative to the amount of modified polyphenylene ether is 10% by mass or more, as this makes it easier to control the loss tangent of the resin substrate within a predetermined range. From the viewpoint of controlling the loss tangent of the resin substrate of this disclosure within a predetermined range, the content of the crosslinking agent relative to the content of modified polyphenylene ether in the resin composition containing modified polyphenylene ether is more preferably 12% by mass or more, even more preferably 15% by mass or more, and particularly preferably 20% by mass or more. From the viewpoint of controlling the loss tangent of the resin substrate of this disclosure to a predetermined range, the content of the crosslinking agent relative to the content of the modified polyphenylene ether in the resin composition containing the modified polyphenylene ether may be 200% by mass or less.

[0045] The resin composition may further contain polymerization initiators. Examples of polymerization initiators include radical polymerization initiators such as organic peroxides, hydroperoxides, and azoisobutyronitrile, and anionic polymerization initiators such as imidazoles, tertiary amines, quaternary ammonium salts, boron trifluoride amine complexes, organophosphines, and organophosphonium salts. Polymerization initiators may be used alone or in combination of two or more.

[0046] The organic solvent in the resin composition is not particularly limited and can be any solvent that dissolves the resin components. For example, examples of organic solvents include methyl ethyl ketone (MEK), toluene, tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and acetonitrile. The organic solvent may be used alone or in combination of two or more.

[0047] [Method for evaluating the dielectric loss tangent of resin compositions] The dielectric loss tangent of a resin composition can be measured by preparing a resin composition film and using the resonance method. The dielectric loss tangent of the resin composition film is preferably evaluated using the method described in the examples.

[0048] [Dielectric loss tangent of resin composition] The dielectric loss tangent of the resin composition at 10 GHz is preferably 0.0045 or less, more preferably 0.0042 or less, even more preferably 0.004 or less, even more preferably 0.0035 or less, particularly preferably 0.0030 or less, and most preferably 0.0025 or less. If the dielectric loss tangent of the resin composition at 10 GHz is 0.0045 or less, the dielectric properties of the printed circuit board are easily improved. Although not particularly limited, the dielectric loss tangent of the resin composition at 10 GHz should be 0.0001 or more.

[0049] [Overall configuration of the resin substrate] The resin substrate of this disclosure contains the above-mentioned glass cloth and the above-mentioned resin composition. This makes it possible to provide a resin substrate with excellent drill wear resistance.

[0050] [Number of glass cloth layers contained in the resin substrate] The number of glass cloth layers contained in the resin substrate is preferably 1 to 10, more preferably 1 to 9, even more preferably 1 to 8, even more preferably 1 to 7, particularly preferably 1 to 6, and most preferably 1 to 5. The number of glass cloth layers contained in the resin substrate is measured by the method described in the examples.

[0051] [Volume fraction of glass cloth contained in the resin substrate] The volume fraction of glass cloth contained in the resin substrate is preferably 10% to 70%, more preferably 11% to 67%, even more preferably 12% to 65%, even more preferably 13% to 63%, and particularly preferably 14% to 60%. When the volume fraction of glass cloth contained in the resin substrate is 10% to 70%, it is easier to improve the drill wear resistance. The volume fraction of glass cloth contained in the resin substrate is measured by the method described in the examples.

[0052] [Dielectric loss tangent of resin substrate] The dielectric loss tangent of the resin substrate of this disclosure at 10 GHz is preferably 0.004 or less, more preferably 0.0035 or less, even more preferably 0.003 or less, even more preferably 0.0028 or less, and particularly preferably 0.0027 or less. If the dielectric loss tangent of the resin substrate at 10 GHz is 0.004 or less, it is easier to obtain a printed circuit board with minimal influence on transmission loss. The dielectric loss tangent of the resin substrate at 10 GHz is measured by the method described in the examples.

[0053] [Loss tangent (tanδ) of resin substrate] The loss tangent (tanδ) of the resin substrate of this disclosure at 200°C is in the range of 0.34 or less. It is known that when drilling resin substrates and metal-clad laminates, the temperature of the cutting area reaches about 200°C. The inventors' research revealed that the smaller the loss tangent of the resin substrate, the more suppressed drill wear is in a diamond-coated drill. When cutting a resin substrate with a drill, it is first necessary to elastically deform the resin. The higher the loss coefficient of the resin, the more the deformation dissipates as thermal energy when elastically deformed, resulting in poor cutting efficiency and a tendency for the temperature of the cutting area to exceed 200°C. Although diamond-coated drills have excellent heat resistance, the inventors have clarified that when drilling a resin substrate with a loss tangent of more than 0.34 at 200°C, the temperature of the cutting area exceeds 200°C, and drill wear progresses significantly.

[0054] From the viewpoint of suppressing drill wear, the loss loss tangent of the resin substrate of this disclosure at 200°C is preferably in the range of 0.30 or less, more preferably in the range of 0.28 or less, even more preferably in the range of 0.26 or less, even more preferably in the range of 0.24 or less, particularly preferably in the range of 0.22 or less, even more preferably in the range of 0.20 or less, far preferably in the range of 0.18 or less, extremely preferably in the range of 0.15 or less, even more extremely preferably in the range of 0.13 or less, and most preferably in the range of 0.11 or less. The loss tangent of the resin substrate at 200°C is measured by the method described in the examples.

[0055] As described later, the loss tangent of a resin substrate can be adjusted not only by the properties of the matrix resin but also by the conditions under which the prepreg is heated and pressure-cured. To reduce the loss coefficient of the resin substrate, it was found that reducing the amorphous component in the resin is effective. Specifically, by making the cooling rate during resin curing slower than conventional methods, the amorphous component in the resin can be reduced, and a resin substrate with a small loss tangent can be obtained. As a result, even a resin substrate using glass cloth woven from high-hardness glass threads with a Si content in the range of 95% to 100% by mass in terms of SiO2 can have excellent drill wear resistance.

[0056] [Glass transition temperature of resin substrates] The glass transition temperature of the resin substrate of this disclosure is preferably 50°C or higher, more preferably 75°C or higher, even more preferably 100°C or higher, and particularly preferably 150°C or higher. If the glass transition temperature of the resin substrate is lower than the predetermined range, the heat resistance will be low, and in processes that involve high-temperature processing such as solder reflow, the resin substrate will deform due to the heat, which is likely to cause a decrease in the yield of printed circuit boards. Although not particularly limited, the glass transition temperature of the resin substrate may be 400°C or lower. The glass transition temperature of the resin substrate is measured by the method described in the examples.

[0057] [Metal-clad laminates and wiring boards] According to this disclosure, a metal-clad laminate is provided which includes the above-mentioned resin substrate and has metal foil (e.g., copper foil) on one or both sides of the surface layer of the resin substrate. Also provided is a wiring board comprising the above-mentioned resin substrate and a wiring pattern for transmitting and receiving electrical signals. The metal-clad laminate and wiring board obtained using the resin substrate of this disclosure are excellent in various properties.

[0058] [Integrated circuits and electronic equipment] According to this disclosure, an integrated circuit including the metal-clad laminate or the wiring board, and an electronic device including the integrated circuit are also provided. The integrated circuit and electronic device obtained using the resin substrate of this disclosure are excellent in various properties.

[0059] Method for manufacturing glass cloth The method for manufacturing glass cloth contained in the resin substrate of this disclosure (hereinafter also referred to as the method for manufacturing glass cloth of this disclosure) includes a step (weaving step: B) in which glass yarn containing a plurality of filaments and having a Si content in the range of 95% to 100% by mass in terms of SiO2 is woven as warp and weft threads to obtain glass cloth. The method for manufacturing glass cloth according to the present disclosure may further include a step of aligning and flattening glass yarns and then applying a sizing agent before the weaving step (warping step: A), a step of washing the glass yarns with water at 50°C or higher before heat de-oiling (pre-heat de-oiling washing step: C) after the warping step and before, during, or after the weaving step, a step of reducing the binder adhering to the glass yarns by heat de-oiling (heat de-oiling step: D), and a step of opening at least a portion of the glass filaments bonded by the binder residue after heat de-oiling (washing and opening step: E). In one embodiment, the method for manufacturing glass cloth according to the present disclosure optionally includes a surface treatment step (surface treatment step: F) of uniformly applying a surface treatment agent to glass filaments, and a step of opening at least a portion of the glass filaments bonded by the surface treatment agent (fiber opening step after surface treatment: G). This makes it possible to improve the drill wear resistance of a metal-clad laminate containing the glass cloth.

[0060] The above glass cloth processing method (steps (C) to (G)) can be applied to quartz glass yarn before weaving, and can also be applied to woven glass cloth. In other words, the step of weaving quartz glass yarn to obtain glass cloth may be provided before or after the glass cloth processing method, or it may be provided in between. The following description will use an example in which steps (A) to (G) are included in this order, but the glass cloth manufacturing method of this disclosure is not limited thereto.

[0061] [Warping process for glass yarn (A)] The glass yarn warping process involves using glass yarn with a Si content in the range of 95% to 100% by mass in terms of SiO2, flattening the yarn bundle, and then sizing the glass yarn. This process, by sizing the yarn while it is widened, facilitates widening the yarn width in the glass cloth after weaving, and allows control so that the yarn width variation coefficient and opening ratio of the glass cloth meet predetermined ranges. The method for flattening the glass fiber bundle is not particularly limited, but examples include processing by applying pressure with a roll. From the viewpoint of flattening the fiber bundle while suppressing fluffing, the pressure is preferably 1.0 kgf / cm 2 ~6.0 kgf / cm² 2 , more preferably 2.0 kgf / cm² 2 ~5.5 kgf / cm² 2 More preferably 2.5 kgf / cm² 2 ~5.0 kgf / cm² 2 That is the case.

[0062] [Weaving process for glass cloth raw fabric (B)] The weaving process for glass cloth raw material involves weaving glass yarn, which contains multiple filaments and has a Si content in the range of 95% to 100% by mass in terms of SiO2, as warp and weft threads. Preferably, the glass yarn is surface-treated with a sizing agent mainly composed of starch and polyvinyl alcohol to suppress fluffing during spinning and warping. The sizing agent treatment may be performed simultaneously with the spinning and warping processes of the glass yarn. Glass cloth raw material is woven by weaving the weft threads into the warp threads obtained in the warping process (A). In this disclosure, "glass cloth raw material" refers to glass cloth before heat de-oiling.

[0063] [Pre-heating oil removal cleaning process (C)] The pre-heating de-oiling washing step includes reducing the adhesive by washing the glass cloth with water at 50°C or higher before heating de-oiling. This reduces adhesion caused by the adhesive on the filaments and the combustion residue of the adhesive during heating de-oiling, and allows the fiber width variation coefficient and opening ratio of the glass cloth to be controlled to meet a predetermined range. From the viewpoint of washing efficiency, water is preferred as the solvent used for washing in this process, and the temperature is preferably 50°C or higher. By using water at 50°C or higher, excess sizing agent can be washed away while retaining the amount of sizing agent necessary to protect the glass yarn until the heat de-oiling process. The water temperature is preferably 50°C or higher and less than 100°C. The lower limit of the water temperature is more preferably 55°C or higher, even more preferably 60°C or higher, and even more preferably 65°C or higher. The upper limit of the water temperature that can be combined with these lower limits is more preferably 95°C or lower, and even more preferably 90°C or lower.

[0064] [Process for reducing the amount of ions adhering to the glass cloth surface] It is known that when the amount of Na ions and / or Mg ions adhering to the surface of the glass cloth is controlled within a predetermined range, a significant decrease in the tensile strength of the glass cloth due to the devitrification of quartz glass can be suppressed even when the glass cloth is heated and de-oiled at high temperatures. Furthermore, to suppress the devitrification phenomenon, washing the glass cloth with a solvent containing low amounts of Na ions and / or Mg ions before heating and de-oiling reduces the amount of Na ions and / or Mg ions on the glass surface, making it possible to suppress the devitrification of quartz glass even when heated and de-oiled at high temperatures. Maintaining the strength of the glass cloth after heating and de-oiling facilitates tension control in subsequent processing steps, thereby suppressing breakage and other damage.

[0065] From the viewpoint of easily suppressing the decrease in the tensile strength of the glass cloth, it is preferable that the solvent used in the glass cloth cleaning solution is a solvent in which the amount of Na ions and / or Mg ions is controlled to predetermined amounts, as shown below. Here, the numerical value (ppm) for the ion content of the cleaning solution indicates the ion content based on the mass of the cleaning solution. By cleaning the glass cloth with a cleaning solution controlled to a predetermined Na ion concentration and / or predetermined Mg ion concentration, Na and / or Mg ions on the surface of the glass cloth can be transferred to the cleaning solution. In addition, Na and / or Mg ions in the cleaning solution can be transferred to and adhered to the surface of the glass cloth.

[0066] The amount of sodium ions in the cleaning solution is preferably 20 ppm or less, more preferably 15 ppm or less, even more preferably 12 ppm or less, even more preferably 10 ppm or less, particularly preferably 7 ppm or less, and most preferably 1.5 ppm or less. If the amount of sodium ions in the cleaning solution is 20 ppm or less, it becomes easier to reduce the amount of sodium ions adhering to the surface of the glass cloth, which makes it easier to suppress the devitrification phenomenon of quartz glass when de-oiling by heating at high temperatures (for example, 600°C to 1500°C), and as a result, it becomes easier to ensure the tensile strength of the glass cloth. The amount of Na ions in the washing solution is measured by the method described in the examples.

[0067] The amount of Mg ions in the cleaning solution is preferably 18 ppm or less, more preferably 12 ppm or less, even more preferably 8 ppm or less, even more preferably 6 ppm or less, particularly preferably 3 ppm or less, and most preferably 1 ppm or less. If the amount of Mg ions in the cleaning solution is 18 ppm or less, it becomes easier to reduce the amount of Mg ions adhering to the surface of the glass cloth, which makes it easier to suppress the devitrification phenomenon of quartz glass when de-oiling by heating at high temperatures (for example, 600°C to 1500°C), and as a result, it becomes easier to ensure the tensile strength of the glass cloth. The amount of Mg ions in the washing solution is measured by the method described in the examples.

[0068] From the viewpoint of easily suppressing the decrease in the tensile strength of the glass cloth, it is preferable that the solvent used to wash the glass cloth is a solvent in which the amount of SO4 ions is controlled to a predetermined amount. By washing the glass cloth with a washing solution of a predetermined SO4 ion concentration, the above ions on the surface of the glass cloth can be transferred to the washing solution, and the above ions from the washing solution can be transferred to and adhered to the surface of the glass cloth.

[0069] The amount of SO4 ions in the cleaning solution is preferably 18 ppm or less, more preferably 12 ppm or less, even more preferably 8 ppm or less, particularly preferably 6 ppm or less, and most preferably 3 ppm or less. If the amount of SO4 ions in the cleaning solution is 18 ppm or less, it becomes easier to reduce the amount of SO4 ions adhering to the surface of the glass cloth, which makes it easier to suppress the devitrification phenomenon of quartz glass when de-oiling by heating at high temperatures (for example, 600°C to 1500°C), and as a result, it becomes easier to ensure the tensile strength of the glass cloth. The amount of SO4 ions in the cleaning solution is measured by the method described in the examples.

[0070] The means for cleaning the glass cloth to reduce the amount of ions adhering to the glass cloth surface may be a method that can reduce Na ions and / or Mg ions on the glass cloth surface, and preferably a method that can further reduce SO4 ions. For example, methods such as ultrasonic methods (e.g., methods using ultrasonic transducers), spraying (e.g., spraying with high-pressure spray), and water vapor atomization can be considered. From the standpoint of low processing cost, a preferred method is to immerse the glass cloth in a tank containing a cleaning solution (a solvent with a Na ion content of 20 ppm or less and / or a solvent with a Mg ion content of 18 ppm or less, preferably a solvent with a SO4 ion content of 18 ppm or less), remove excess cleaning solution with a squeeze roller or the like, and then dry the glass cloth. For example, the immersion time for the glass cloth can be 2 seconds or more, 5 seconds or more, 10 seconds or more, or 15 seconds or more as a lower limit, and 120 seconds or less, 90 seconds or less, 60 seconds or less, or 45 seconds or less as an upper limit.

[0071] As the solvent for the washing solution, water is preferred, water with a Na ion content of 20 ppm or less and / or a Mg ion content of 18 ppm or less is more preferred, and water with a Na ion content of 20 ppm or less and / or a Mg ion content of 18 ppm or less and / or an SO4 ion content of 18 ppm or less is even more preferred. The method for producing water with a Na ion content of 20 ppm or less and / or a Mg ion content of 18 ppm or less and / or an SO4 ion content of 18 ppm or less may be a known production method. For example, methods such as filtration using an RO membrane, deionization using an ion exchange resin, and distillation can be considered. The solvent used in the cleaning solution may contain other liquid components (liquids other than water, etc.) as long as they do not impair the effects of this disclosure. The solvent may also be a lower alcohol (such as methanol), or a mixture of water and a lower alcohol.

[0072] [Heating deoiling process (D)] In step (D) of heating and de-oiling the glass cloth, heating the glass yarn reduces any sizing agents, their residues, and modified substances that may be arbitrarily attached to the glass yarn, and preferably removes them. By performing the heating and de-oiling step, it becomes possible to form a surface treatment layer on the surface of the glass yarn (glass filament) after reducing organic substances that can increase the dielectric loss tangent, making it easier to produce glass cloth with excellent dielectric properties. Known methods (heating means, heating medium, heating mechanism, heating device, and heating component, etc.) can be used as means for heat-based oil removal.

[0073] One known method of the heat-based oil removal process involves heating the glass cloth to a temperature of 600 to 1600°C.

[0074] In the heat de-oiling process, heating raw glass cloth, which has a glass fiber softening point of 900°C or higher, in a temperature range of 600°C to 1600°C makes it easier to minimize damage to the glass cloth and to reduce the dielectric loss tangent of the glass cloth. From the viewpoint of suitably obtaining the effects of this disclosure, the heat de-oiling temperature is preferably 700°C to 1500°C, more preferably 800°C to 1400°C, even more preferably 900°C to 1300°C, and particularly preferably 1000°C to 1200°C. If the degreasing temperature is 600°C or higher, it is easier to effectively remove sizing agents and other substances adhering to the glass cloth, making it easier to produce glass cloth with excellent dielectric properties. If the degreasing temperature is 1600°C or lower, it is easier to suppress the devitrification phenomenon of the glass cloth, and as a result, it is easier to prevent a decrease in the strength of the glass cloth.

[0075] The heating time is preferably 30 minutes or less, more preferably 15 minutes or less, even more preferably 5 minutes or less, and particularly preferably 90 seconds or less. Because the heat treatment is performed at a high temperature, a heating time of 30 minutes or less tends to reduce damage to the glass cloth, making it easier to avoid problems such as partial holes forming in the glass cloth or the glass cloth cutting during processing. The heating time may be, for example, 1 second or more, 5 seconds or more, 10 seconds or more, or 15 seconds or more, from the viewpoint of effectively removing sizing agents, etc.

[0076] When performing heat de-oiling of glass cloth in a closed system, it is preferable to place the glass cloth inside the heating furnace from the viewpoint of optimal heating by the heating means. Furthermore, from the viewpoint of efficient storage space and heating range, it is preferable to heat the glass cloth while storing it in a roll. Moreover, from the viewpoint of improving the efficiency of organic matter removal and shortening the organic matter removal time, it is preferable to heat the glass cloth while transporting it inside the heating furnace. The transport of the glass cloth can be performed, for example, by a combination of an unwinding mechanism and a winding mechanism.

[0077] When performing heat degreasing of glass cloth in an open system, it is preferable to heat the glass cloth while transporting it, from the viewpoint of ensuring a sufficient heating surface area. The glass cloth can be transported, for example, by a combination of an unwinding mechanism and a winding mechanism.

[0078] The form of the heating and de-oiling process is not limited to the above. As another embodiment of the heating de-oiling process, for example, a method is known in which the heating amount, expressed as heating temperature (°C) × heating time (h) of 100°C or higher, is 450°C·h or higher in a vacuum or in a gas with a dew point of 15°C or lower (provided that the maximum heating temperature is between 100 and 600°C).

[0079] <Heating means> Possible heating methods include, for example, a heating furnace, an electric heater, and a burner, with gas-powered single-radiant tube burners or electric heaters being preferred. Multiple different heating methods may be combined.

[0080] From the viewpoint of efficiently removing organic matter adhering to the surface of the glass cloth, a continuous heating method in which the glass cloth is continuously passed through a heating furnace is preferred over a batch method in which the glass cloth wound on a core is heated at a predetermined ambient temperature. A method that allows for continuous washing of the glass cloth using washing water with a low metal ion content, such as reverse osmosis (RO) water or ion-exchanged water, is even more preferable.

[0081] Furthermore, as a heating means, from the viewpoint of low running costs, the glass cloth may be heated by bringing a member (contact member) heated to a predetermined temperature into contact with the glass cloth.

[0082] The contact member should be capable of heating the glass cloth to a high temperature. A roll shape is preferred for the contact member due to its ease of transporting the glass cloth. Specifically, a roll that uses induction heating is preferred as the contact member, for example, as it can be used in high-temperature regions and has relatively little temperature variation in the width direction. When heating the glass cloth with the contact member, the temperature of the contact member and the surface temperature of the glass cloth are considered to be approximately equal.

[0083] When continuously heating glass cloth, in order to remove charred material adhering to the roll, the method using the roll described above preferably includes a mechanism for removing the adhering foreign matter, such as a blade.

[0084] <Means of applying steam> The means for heating the glass cloth (steam application means) can be spray, shower diffusion, and jet nozzles, etc. Alternatively, the gas discharged from the heating furnace can be reused as high-temperature steam.

[0085] The vapor applied to the glass cloth may include, for example, volatile solvents, water vapor, and gases other than water vapor, but water vapor is preferred from the viewpoint of suppressing toxicity to the human body and from the viewpoint of easily promoting the decomposition of the sizing agent used in the glass fibers. The temperature of the high-temperature vapor may be higher than 650°C above the surface temperature of the glass cloth, and in this case, if necessary, a method may be adopted in which high-temperature vapor and heated air can be supplied in any ratio. The temperature of the high-temperature vapor may be 400°C or higher, 450°C or higher, 550°C or higher, 600°C or higher, or 650°C or higher.

[0086] [Washing and opening process of glass cloth (E)] Preferably, the glass cloth of this disclosure can be obtained by performing a step (E) on the glass cloth after heating and de-oiling, in which the areas where glass filaments are bonded together by binder residue are opened. From the viewpoint of sufficiently and uniformly opening the glass cloth, the washing and opening step (E) preferably includes an opening step of irradiating the glass cloth with ultrasonic waves in a liquid to open the fibers.

[0087] Because quartz glass has a higher hardness compared to other types of glass, it is known that conventional fiber-opening processes do not adequately and uniformly open the fibers. By performing a fiber-opening process after heating and de-oiling, and as described below, after (G) surface treatment, the glass cloth is more easily opened adequately and uniformly, and it becomes possible to control the fiber width variation coefficient and opening ratio to satisfy a predetermined range. If the fiber width variation coefficient and opening ratio are within the predetermined range, the glass cloth is opened adequately and uniformly, and there are fewer areas where bundles of hard quartz glass fibers are localized in the direction of drilling, making it easier to obtain the effect of improving the drill wear resistance with the resin composition.

[0088] In the washing and fiber opening process, in addition to the process of opening the fiberglass cloth by irradiating it with ultrasound in a liquid, other fiber opening methods may be included in the process. Other fiber opening methods include immersing the fiberglass cloth in a liquid, immersing the fiberglass cloth in a liquid and applying force to the fiberglass cloth through the liquid (e.g., vibro-washer method, ultrasonic method), and spraying the fiberglass cloth with liquid forcefully (e.g., high-pressure spray method). The fiberglass cloth can also be opened by immersing it in a liquid in a roll state, or, from the viewpoint of productivity, a method of opening the fiberglass cloth while conveying it roll-to-roll using a device having an unwinding mechanism and a winding mechanism is preferred.

[0089] For fiber opening, either water or an organic solvent can be used, but from the standpoint of safety and environmental protection, it is preferable to use a liquid with water as the main component. Surfactants and pH adjusters can also be added to the cleaning liquid to improve fiber opening efficiency.

[0090] There are no particular restrictions on the temperature of the liquid used for fiber opening, but from the viewpoint of enhancing the effect, a temperature of 5°C or higher is preferred. Furthermore, from the viewpoint of safety, a temperature of 60°C or lower is preferred for the liquid used for fiber opening.

[0091] Since it is preferable to remove as much binder residue as possible after heating and de-oiling before subjecting the material to the surface treatment process, it is preferable to use a method of opening the fibers by irradiating the glass cloth with ultrasound in water, from the viewpoint of improving cleaning power.

[0092] By running glass cloth through a liquid irradiated with ultrasonic waves by an ultrasonic oscillator, the glass cloth can be opened by irradiating it with ultrasonic waves in the liquid. The line tension acting on the warp threads during the opening process is preferably 30N to 500N per 1m of glass cloth width. When the line tension acting on the warp threads is 30N per 1m or more of glass cloth width, there is no slack in the glass cloth and the warp threads are uniformly taut without loosening, so the opening of the fibers by ultrasonic waves can be performed evenly.

[0093] For opening glass cloth fibers by ultrasonic irradiation, ultrasound with a frequency of 20 kHz to 200 kHz can be used. The ultrasonic frequency is preferably between 20 kHz and 50 kHz, and more preferably between 20 kHz and 30 kHz. It is preferable that the ultrasonic frequency is within the above range because it allows for sufficient and uniform fiber opening of the glass cloth, making it easier to control the yarn width variation coefficient and aperture ratio within a predetermined range.

[0094] For opening glass cloth fibers using ultrasonic irradiation, 0.02 W / cm² is required. 2 The above is 3.60 W / cm². 2 Ultrasound with the following output levels can be preferably used. A more preferable range for ultrasonic output is 0.04 W / cm². 2 More than 2.16W / cm 2 A more preferable range is 0.07 W / cm². 2 More than 1.44W / cm 2 The following is preferable: If the ultrasonic output is within the above range, the glass cloth can be opened sufficiently and uniformly, and the coefficient of variation of the yarn width and the aperture ratio can be easily controlled within a predetermined range. For opening glass cloth fibers using ultrasonic irradiation, an ultrasonic output of 0.02 W / cm is required. 2 The above is preferable, and 0.04 W / cm² 2 The above is more preferable, 0.07 W / cm²2 The above is even more preferable, 0.14 W / cm² 2 The above is even more preferable, 0.21 W / cm² 2 The above are particularly preferable. For opening glass cloth fibers using ultrasonic irradiation, an ultrasonic output of 3.60 W / cm² is required. 2 The following is preferable: 2.16 W / cm² 2 The following is more preferable: 1.44 W / cm² 2 The following is even more preferable.

[0095] The preferred ultrasonic treatment time is between 0.5 seconds and 60 seconds. An ultrasonic treatment time of 0.5 seconds or more is preferable because it effectively opens the glass cloth or its intermediates. A longer ultrasonic treatment time is preferable because it yields a greater opening effect, but since there is almost no further opening even if the treatment is performed for more than 60 seconds, 60 seconds or less is sufficient.

[0096] The liquid used in ultrasonic cleaning typically contains dissolved air, mainly composed of nitrogen and oxygen. The amount of dissolved oxygen (by weight) is preferably between 1 ppm and 20 ppm, more preferably between 3 ppm and 17 ppm, and even more preferably between 4 ppm and 14 ppm. By controlling the amount of dissolved oxygen, it is possible to indirectly control the amount of dissolved gas, thereby controlling the degree to which the ultrasound is attenuated by the dissolved gas. To ensure uniform fiber opening, the amount of dissolved oxygen in the liquid used in ultrasonic cleaning is preferably 1 ppm or more. A dissolved oxygen level of 20 ppm or less is preferable because it provides a good fiber opening effect to the textile. A dissolved oxygen level between 1 ppm and 20 ppm is preferable because it provides a uniform and good fiber opening effect.

[0097] [Surface treatment process for glass cloth (F)] The surface treatment step (F) in which a surface treatment agent is applied can be applied to glass yarn and can also be applied to glass cloth. In other words, the step of weaving glass yarn to obtain glass cloth may be provided before or after the glass cloth processing method according to this embodiment, or it may be provided in between.

[0098] The process of applying the surface treatment agent includes, for example, a coating process in which a silane coupling agent is applied to the surface of the glass using a treatment solution with a concentration of 0.1 to 0.5% by mass, A fixing process in which the silane coupling agent is fixed to the surface of the glass by heat drying, At least one of the following steps may be performed. Performing the surface treatment step (F) makes it easier to suitably surface treat the glass cloth.

[0099] In the coating process, the following methods can be used to apply the processing solution to the glass cloth: (a) immersing or passing the glass cloth through the processing solution stored in a bath (hereinafter referred to as the "immersion method"), and (b) applying the processing solution to the glass cloth using a roll coater, die coater, or gravure coater. When using the immersion method, it is preferable to set the immersion time of the glass cloth in the processing solution to 0.5 seconds or more and 1 minute or less. When using the immersion method, the glass cloth can be passed through the processing solution at a transport speed of 10 to 50 m / min while applying a predetermined tension (e.g., 100 to 250 N) to the glass cloth. After applying the processing solution to the glass cloth, the solvent contained in the processing solution can be heated and dried using methods such as hot air and electromagnetic waves.

[0100] As the treatment solution, for example, a silane coupling agent (e.g., 3-methacryloyloxypropyltrimethoxysilane; OFS6030, manufactured by Dow-Toray) can be dispersed in pure water adjusted to pH=3 and adjusted to a predetermined concentration. The concentration of the treatment solution is preferably 0.1 to 0.5% by mass, more preferably 0.1 to 0.45% by mass, and even more preferably 0.1 to 0.4% by mass. Within this predetermined concentration range, the glass cloth can be more easily and effectively surface-treated. The immersion time in the treatment solution is preferably 0.5 seconds to 1 minute, and more preferably 1 second to 30 seconds. If the immersion time in the treatment solution is within the specified range, the glass cloth will be more easily surface-treated.

[0101] In the fixing process, the heating and drying temperature is preferably 80°C or higher, and more preferably 90°C or higher, so that the reaction between the silane coupling agent and the glass cloth can proceed sufficiently. Furthermore, the heating and drying temperature is preferably 300°C or lower, and more preferably 180°C or lower, in order to prevent deterioration of the organic functional groups of the silane coupling agent.

[0102] A process to reduce the amount of silane coupling agent includes, for example, a cleaning process to wash away the silane coupling agent that did not form a chemical bond with the surface of the glass cloth, A drying process in which the glass cloth is heated and dried after washing, At least one step may be performed, which is a finishing cleaning step to reduce unwanted components that were not completely removed and do not form chemical bonds with the surface of the glass cloth. By implementing a process to reduce the amount of silane coupling agent, it becomes easier to control the ignition loss of the glass cloth. The process of reducing the silane coupling agent may include, for example, a finish drying step after the finish cleaning step.

[0103] In this process, the final cleaning step can reduce unwanted components that were not completely removed in the cleaning step and do not form chemical bonds with the surface of the glass cloth. For example, an organic solvent can be used as the cleaning solution in this final cleaning step. Having a final cleaning step makes it easier to lower the dielectric loss tangent of the glass cloth. The organic solvent used here is preferably a highly hydrophobic organic solvent, and also preferably an organic solvent that has a high affinity for the residue and modified product of the silane coupling agent having a hydroxyl group. The washing method can be immersion or shower spray, and heating or cooling may be applied as needed. To prevent the glass cloth dissolved in the washing solution from reattaching to unwanted components, it is preferable to reduce the excess solvent from the glass cloth after washing using a squeezing roller or the like.

[0104] In the final cleaning process, the organic solvents that can be used as cleaning solutions include, for example, the following solvents, either individually or in combination. Examples of highly hydrophobic organic solvents include, Saturated chain aliphatic hydrocarbons such as n-pentane, i-pentane, n-hexane, i-hexane, n-heptane, i-heptane, n-octane, i-octane, 2,2,4-trimethylpentane (isooctane), n-nonane, i-nonane, n-decane, i-decane, and 2,2,4,6,6-pentamethylheptane (isododecane); Saturated cyclic aliphatic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, and ethylcyclohexane; Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, and triethylbenzene; and Halogen-containing solvents such as chloroform, dichloromethane, and dichloroethane; These are some examples.

[0105] Organic solvents that have a high affinity for the residue or modified product of silane coupling agents include: Alcohols such as methanol, ethanol, and butanol; Acetone and ketones such as methyl ethyl ketone; Ethers such as methyl ethyl ether and diethyl ether; Amides such as N,N-dimethylformamide and N,N-dimethylacetamide; and Dimethyl sulfoxide; These are some examples. In particular, aromatic hydrocarbons, alcohols, or ketones are preferred, and methanol is more preferred, from the viewpoint of being able to efficiently reduce the silane coupling agent that is physically attached to the glass cloth. Therefore, it is preferable to use a cleaning solution in the final cleaning process in which methanol is the main component (50% or more by mass of methanol, or 60% or more by mass, per 100% by mass of the cleaning solution).

[0106] In the final drying process, the amount of cleaning solution used in the final cleaning process can be reduced. Due to the ease of reducing the amount of cleaning solution by drying, it is preferable that the cleaning solution used in the final cleaning process has a boiling point of 120°C or lower. For drying, heating drying or forced-air drying methods can be employed. When an organic solvent is used as the cleaning solution, from a safety standpoint, it is preferable to perform heating drying by hot air drying using low-pressure steam or heat transfer oil as the heat source. The drying temperature is preferably above the boiling point of the cleaning solution, and is preferably 180°C or lower from the viewpoint of suppressing the deterioration of the silane coupling agent. The drying time is preferably 30 seconds or less.

[0107] [Fiber opening process after surface treatment (G)] As for the step (G) of opening at least a portion of the glass filaments bonded with a surface treatment agent, a method of opening the glass cloth with spray water (for example, high-pressure water) is preferred from the viewpoint of opening the glass cloth sufficiently and uniformly.

[0108] Because quartz glass has a higher hardness compared to other types of glass, it is known that conventional fiber-opening processes do not adequately and uniformly open the fibers. By performing a sufficient fiber-opening process on the glass cloth after heating, de-oiling, and surface treatment, the glass cloth is more easily opened adequately and uniformly, and it becomes possible to control the fiber width variation coefficient and opening ratio to meet predetermined ranges. If the fiber width variation coefficient and opening ratio are within the predetermined range, the glass cloth is sufficiently and uniformly opened, and there are fewer areas where bundles of hard quartz glass fibers are localized in the direction of drilling, making it easier to obtain the effect of improving the drill wear resistance of the resin composition.

[0109] The spray water pressure is 0.5 kgf / cm². 2 The above is 15.0 kgf / cm². 2 The following ranges are preferred, and more preferably, 0.8 kgf / cm². 2 The above is 10.0 kgf / cm². 2 The following, and more preferably 1.0 kgf / cm² 2The above is 5.0 kgf / cm². 2 The range is as follows. Within the above range, the glass cloth can be opened sufficiently and uniformly, and it is preferable because the coefficient of variation of the yarn width and the opening ratio can be easily controlled within a predetermined range. The spray water pressure is 0.5 kgf / cm². 2 The above is preferable, and 0.8 kgf / cm² 2 The above is more preferable, 1.0 kgf / cm² 2 The above is even more preferable. The spray water pressure is 15.0 kgf / cm². 2 The following is preferable: 10.0 kgf / cm² 2 The following is more preferable: 5.0 kgf / cm² 2 The following is even more preferable.

[0110] During this fiber-opening process, reducing the tension applied to the glass cloth tends to allow for a smaller opening ratio. To minimize the decrease in the tensile strength of the glass cloth due to the fiber-opening process, it is preferable to implement measures such as reducing friction with the contact material when weaving the glass yarn, optimizing the sizing agent, and increasing its adhesion amount.

[0111] The processes described above do not necessarily have to be performed in separate processes; multiple processes can be combined into a single process. For example, if the washing process is performed after the weaving process, the washing process can also serve as the fiber opening process by using a high-pressure water spray or the like. The composition of the glass cloth usually does not change before and after fiber opening. Furthermore, the manufacturing method of glass cloth can include any other processes besides those described above. For example, a slitting process can be added after the fiber opening process. Also, if possible, the order of the above processes can be changed.

[0112] According to the glass cloth manufacturing method described above, it is possible to sufficiently and uniformly open the glass cloth fibers and control the yarn width variation coefficient and opening ratio to satisfy a predetermined range, thereby improving the drill wear resistance of the metal-clad laminate containing the glass cloth.

[0113] 《Prepreg manufacturing method》 The method for manufacturing the prepreg is not limited and known techniques can be used. For example, one method involves impregnating the glass cloth with the resin composition and then drying off the solvent using a hot air dryer or the like.

[0114] The slit width after immersing the glass cloth in the resin composition varies depending on the type of glass cloth, resin, and organic solvent, but from the viewpoint of scraping off excess resin composition, for example, a range of 100 to 500 μm is possible. The drying temperature and drying time after immersing the glass cloth in the resin composition vary depending on the type of resin and organic solvent, but from the viewpoint of thoroughly drying and removing the solvent, for example, drying at 100 to 200°C for 30 seconds to 10 minutes is recommended.

[0115] Processing methods for metal-clad laminates The method for processing the metal-clad laminate is not limited and known techniques can be used. For example, one method involves layering a metal foil (e.g., copper foil) on the surface of the prepreg, and then curing the resin composition by heating and pressurizing to obtain a metal-clad laminate in which a cured laminate is laminated.

[0116] Heating and pressurization can be performed using, for example, a multi-stage press, a vacuum press, a multi-stage vacuum press, continuous molding, and an autoclave molding machine. The heating temperature during heating and pressurizing is preferably in the range of 100 to 300°C, more preferably 150 to 250°C, and even more preferably 170 to 230°C, from the viewpoint of sufficiently curing the resin. The heating and pressurizing time is preferably in the range of 60 to 300 minutes, more preferably 60 to 180 minutes, and even more preferably 60 to 120 minutes, from the viewpoint of sufficiently curing the resin. The pressure applied during heating and pressurizing should be between 10 and 80 kgf / cm², from the viewpoint of ensuring sufficient curing of the resin. 2 A range of 20-60 kgf / cm² is preferred. More preferably 20-60 kgf / cm². 2 The range is, more preferably, 30-50 kgf / cm². 2 It is within the range of [the specified range].

[0117] Heating and pressurizing can be performed, for example, by starting pressurizing simultaneously with the start of heating. The heating rate is preferably in the range of 0.5 to 10°C / min, and more preferably in the range of 1 to 5°C / min. If the heating rate is 10°C / min or less, the resin can be sufficiently softened before maintaining the heating and pressurizing at the maximum temperature. If the heating rate is 0.5°C / min or more, productivity can be maintained without the heating time becoming too long. From the viewpoint of sufficiently curing the resin, the duration of heating and pressurizing at the maximum temperature is preferably in the range of 30 to 240 minutes, and more preferably in the range of 30 to 180 minutes.

[0118] Heating and pressurizing can be carried out, for example, under vacuum. From the viewpoint of reducing air entrainment, the vacuum pressure is preferably 50 mmHg or less, more preferably 20 mmHg or less, and even more preferably 10 mmHg or less.

[0119] To reduce the loss tangent of the resin substrate to 0.34 or less, the cooling rate after heating and pressurizing is performed within the range of 0.5 to 3.0°C / min. By performing the cooling rate at a lower speed than conventional methods, the amount of amorphous components in the cured resin is reduced, making it possible to lower the loss tangent of the resin substrate. From the viewpoint of easily obtaining the effects of this disclosure, the cooling rate is preferably in the range of 0.6 to 2.0°C / min, more preferably in the range of 0.7 to 1.5°C / min, even more preferably in the range of 0.8 to 1.2°C / min, and particularly preferably in the range of 0.8 to 1.1°C / min. If the cooling rate is below the predetermined range, the time required for cooling becomes very long, and the productivity of the resin substrate and metal-clad laminate decreases. If the cooling rate exceeds the predetermined range, the amount of amorphous components in the resin composition increases, making it difficult to adjust the loss tangent to 0.34 or less.

[0120] Processing methods for resin substrates The method for processing the resin substrate is not limited and known techniques can be used. For example, one method is to remove the copper foil from the above-mentioned metal-clad laminate by etching with an aqueous iron(III) chloride solution. [Examples]

[0121] Examples and comparative examples of the present disclosure will be described in detail below, but the present disclosure is not limited to the following examples and comparative examples.

[0122] [Method for preparing resin composition A] To 45.0 parts by mass of toluene as a solvent, 44.0 parts by mass of modified polyphenylene ether (product name: SA-9000, manufactured by SABIC Innovative Plastics Co., Ltd.) and 5.4 parts by mass of silica filler (product name: CRS1057 EXR-3F, ​​manufactured by Ryusen Co., Ltd.) were added, and stirring was continued until the modified polyphenylene ether dissolved. Next, 5.5 parts by mass of triallyl isocyanurate (manufactured by Mitsubishi Chemical Corporation) and 0.1 parts by mass of organic peroxide (product name: Perbutyl P, manufactured by NOF Corporation) were added to the solution as radical polymerizable compounds, and the mixture was stirred thoroughly to obtain resin composition A.

[0123] [Method for preparing resin composition B] The resin composition was prepared in the same manner as resin composition A, except that the mixing ratio was adjusted to match the formulation shown in Table 1.

[0124] [Method for preparing resin composition C] To 45.0 parts by mass of toluene as a solvent, 43.4 parts by mass of modified polyphenylene ether (product name: SA-9000, manufactured by SABIC Innovative Plastics Co., Ltd.), 0.6 parts by mass of elastomer (product name: ToughTec H1041, manufactured by Asahi Kasei Corporation), and 5.4 parts by mass of silica filler (product name: CRS1057 EXR-3F, ​​manufactured by Ryusen Co., Ltd.) were added, and stirring was continued until the modified polyphenylene ether dissolved. Next, 5.5 parts by mass of triallyl isocyanurate (manufactured by Mitsubishi Chemical Corporation) and 0.1 parts by mass of organic peroxide (product name: Perbutyl P, manufactured by NOF Corporation) were added as radical polymerizable compounds, and the mixture was stirred thoroughly to obtain resin composition C.

[0125] [Methods for preparing resin compositions D, E, and G] The resin composition was prepared in the same manner as resin composition C, except that the mixing ratio was adjusted to match the formulation shown in Table 1.

[0126] [Method for preparing resin composition F] To 33.8 parts by mass of methyl ethyl ketone as a solvent, 18.2 parts by mass of bisphenol A novolac type epoxy resin (product name: EPICLON N-865, manufactured by DIC Corporation), 24.7 parts by mass of brominated bisphenol A type epoxy resin diluent (product name: EPICLON 153-60T, manufactured by DIC Corporation), 5.1 parts by mass of bisphenol A type epoxy resin diluent (product name: EPICLON 1051-75M, manufactured by DIC Corporation), 12.7 parts by mass of bisphenol A novolac resin (product name: PHENOLITE VH-4170, manufactured by DIC Corporation), and 5.4 parts by mass of silica filler (product name: CRS1057 EXR-3F, ​​manufactured by Ryumori Co., Ltd.) were added, and stirring was continued until the resin components were sufficiently dissolved. Next, 0.1 parts by mass of 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the solution as a curing agent, and the mixture was thoroughly stirred to obtain resin composition F.

[0127] [Preparation of resin composition film] The prepared resin composition was coated onto a release-treated Kapton film at a speed of 30 mm / second, and then dried in a nitrogen-flow forced-air dryer (product name: DN411I, manufactured by Yamato Scientific Co., Ltd.) at 100°C for 30 minutes. The dried film was then cured at 200°C for 90 minutes using the nitrogen-flow forced-air dryer to obtain a resin composition film containing the cured resin composition. The thickness of the obtained resin composition film was determined using a micrometer (product name: MDC-25PX, manufactured by Mitutoyo Corporation) by gently rotating the micrometer's spindle and lightly contacting it parallel to the measuring surface of the resin composition film, and reading the scale after the ratchet clicked three times.

[0128] 《Measurement method》 [Method for evaluating yarn width, yarn width standard deviation, and yarn width variation coefficient in the warp and weft directions of glass cloth] The warp and weft widths of the glass cloth were determined using the following method. First, five glass cloth samples were cut from the glass cloth, each measuring 100 mm in the warp direction and 100 mm in the weft direction. Each cut sample was observed vertically using a microscope at 100x magnification. For each sample, the width of 250 warp (or weft) threads was randomly measured, and the average value, standard deviation, and coefficient of variation of the obtained 250 warp (or weft) thread widths were calculated. The yarn width variation coefficient was calculated using the following formula: Yarn width variation coefficient = Yarn width standard deviation [μm] ÷ Yarn width average [μm].

[0129] [Method for evaluating the aperture ratio of glass cloth] Using the yarn width obtained by the method described above, The opening ratio of the glass cloth was calculated according to the formula: Opening ratio [%] = ((25400 / warp density [threads / inch] - warp width [μm]) × (25400 / weft density [threads / inch] - weft width [μm]) × 100) / ((25400 / warp density [threads / inch]) × (25400 / weft density [threads / inch])).

[0130] [Method for evaluating the thickness of glass cloth] In accordance with JIS R3420 7.10, the thickness (μm) of each glass cloth was determined by using a micrometer, gently rotating the spindle and lightly contacting it parallel to the measuring surface, and reading the scale after the ratchet clicked three times.

[0131] [Method for evaluating the basis weight (mass) of glass cloth] The glass cloth was cut to a predetermined size, and its mass was determined by dividing it by the sample area. In this example, the glass cloth was 10 cm 2 By cutting the glass cloth to the appropriate size and measuring its mass, the basis weight (g / m²) of each glass cloth can be determined. 2 ) was sought.

[0132] [Method for evaluating the converted thickness of glass cloth] Glass cloth is a discontinuous planar material with air between the glass fibers. Therefore, the converted thickness was calculated by dividing the basis weight (mass of the glass cloth) of each glass cloth by the density of the glass. Specifically, the formula is: Equivalent thickness of glass cloth (μm) = Basis weight of glass cloth (g / m²) 2 ) / Density of glass (g / cm³) 3 The converted thickness of the glass cloth was calculated using the following method. This converted thickness value was used to measure the dielectric loss tangent of the glass cloth using the resonance method.

[0133] [Method for evaluating the dielectric loss tangent of glass cloth and resin composition films] In accordance with IEC 62562, the dielectric loss tangent of glass cloth and resin composition film at 10 GHz was determined. Specifically, samples of glass cloth or resin composition film, sampled to the size required for measurement in a split cylinder resonator, were stored in a constant temperature and humidity oven at 23°C and 50% RH for at least 8 hours. After storage, the dielectric loss tangent of the glass cloth and resin composition film was measured using a split cylinder resonator (EM Labs) and an impedance analyzer (Agilent Technologies). Measurements were performed five times for each sample, and the average value was calculated. For glass cloth, the above-mentioned converted thickness was used as the thickness of each sample. For resin composition film, the value obtained with a micrometer was used. The values ​​obtained from the measurements were treated as the dielectric loss tangent values ​​of the glass cloth and resin composition in this disclosure.

[0134] [Method for evaluating the tensile strength of glass cloth] In accordance with the method described in JIS R3420, five tensile tests were performed on the glass cloth in both the warp and weft directions, and the tensile strength (N / 25mm) of the glass cloth in both the warp and weft directions was determined from the average value.

[0135] [Method for evaluating the tensile strength per unit thickness of glass cloth] The tensile strength per unit thickness (N / 25mm / μm) of the glass cloth in the warp and weft directions was determined by applying the glass cloth thickness and tensile strength values ​​obtained by the above method to the formula: Tensile strength of glass cloth (N / 25mm) / Thickness of glass cloth (μm).

[0136] [Method for manufacturing resin substrates] A resin substrate was obtained by removing the copper foil present on both sides of the metal-clad laminate obtained by the method described in the Examples and Comparative Examples. Specifically, the copper foil was removed by immersing the metal-clad laminate in a 39.0% by mass iron(III) chloride aqueous solution and etching it for 60 minutes, thereby obtaining a resin substrate.

[0137] [Method for evaluating the number of glass cloth layers contained in a resin substrate] The number of glass cloth layers contained in the resin substrate was measured by cross-sectional observation of the resin substrate using a scanning electron microscope (SEM).

[0138] [Method for evaluating the thickness of resin substrates] Using a micrometer, the spindle was gently rotated and lightly brought into contact with the measurement surface of the resin substrate parallel to it. The thickness of the resin substrate (μm) was determined by reading the scale after the ratchet clicked three times.

[0139] [Method for evaluating the volume fraction of glass cloth contained in a resin substrate] The volume fraction of glass cloth contained in the resin substrate was calculated by applying the values ​​of the converted thickness of the glass cloth and the thickness of the resin substrate to the formula: Volume fraction (%) = Converted thickness of glass cloth (μm) × Number of layers of glass cloth contained in the resin substrate / Thickness of the resin substrate (μm) × 100.

[0140] [Method for evaluating the dielectric loss tangent of resin substrates] The dielectric loss tangent of a resin substrate at 10 GHz was determined in accordance with IEC 62562. Specifically, the dielectric loss tangent was measured on resin substrate samples, sampled to the size required for measurement in a split-cylinder resonator, using a split-cylinder resonator (EM Labs) and an impedance analyzer (Agilent Technologies). Each sample was measured five times, and the average value was calculated. The thickness of each sample was determined from the resin substrate thickness calculated above.

[0141] [Measurement of Na ion, Mg ion, and SO4 ion content in the washing solution] The amounts of Na ions, Mg ions, and SO4 ions in the washing solution used to wash the glass cloth before heating and de-oiling were measured using ion chromatography under the following conditions.

[0142] <Pretreatment conditions> Washing solution (sample) was prepared by diluting with distilled water as needed.

[0143] <Cation Ion Chromatography Conditions> Equipment:Tosoh,IC-2010 Separation column: Tosoh, TSKgel-Super IC-Cation / P (4.6mm x 150mm) Separated solution: 2.5 mM HNO3 + 0.5 mM L-histidine Flow rate: 1.0mL / min Detection: Electrical conductivity Column temperature: 40℃ Injection volume: 30μL

[0144] <Anion Ion Chromatography Conditions> Equipment:Tosoh,IC-2010 Separation column: Tosoh, TSKgel-Super IC-AZ (4.6mm x 150) (mm) Eluent: 6.3mM NaHCO3+1.7mM Na2CO3 Flow rate: 0.8mL / min Detection: Electrical conductivity Column temperature: 40℃ Injection volume: 30μL

[0145] [Cleaning solution used in the pre-heating oil removal cleaning process] Three types of cleaning solutions were prepared for use in the pre-heating oil removal cleaning process. Washing solution 1: Na ions = 1.6 ppm, Mg ions = 0 ppm, SO4 ions = 0 ppm Washing solution 2: Na ions = 2.5 ppm, Mg ions = 0.1 ppm, SO4 ions = 0.5 ppm Washing solution 3: Na ions = 0 ppm, Mg ions = 0 ppm, SO4 ions = 0 ppm

[0146] (Example 1) (A) The warp preparation process was performed using glass yarn with an SiO2 content greater than 99.9% by mass, an average filament diameter of 5.0 μm, 100 filaments, and a twist count of 1.0 Z (T / m). At this time, the warp yarns, which were aligned at a transport speed of 60 m / min, were subjected to a pressure of 3.0 kgf / cm 2 The glass yarn was flattened by nipping it with a roll under a load. Then, a sizing agent mainly composed of polyvinyl alcohol (PVA) resin was applied using the following procedure. Specifically, an aqueous solution of PVA (product name: PVA403, manufactured by Kuraray Co., Ltd.) with a concentration of 5% by mass was prepared, and 2% by mass of hydrogenated castor oil was added to this aqueous solution as a lubricant to obtain the sizing agent. The sizing agent, which had been kept warm at 60°C, was applied to the glass yarn and then dried to perform the sizing treatment. After that, glass cloth fabric was woven using an air jet loom with a weaving density of 66 warp threads / inch and 68 weft threads / inch. As the weft, glass yarn with an average filament single diameter of 5.0 μm, 100 filaments, and a twist count of 1.0 Z (T / m) was used.

[0147] The obtained raw glass cloth was transported at a line speed while being immersed in a tank containing 60°C washing solution 1 for 15 seconds to wash away the sizing agent adhering to the glass surface ((C) Pre-heating and de-oiling washing process). Subsequently, the glass cloth was heated at 1000°C for 15 seconds in an air atmosphere using a roll-to-roll method in a heating furnace located on the same line (D) Heating and de-oiling process. Using the glass cloth after heating and de-oiling, continuous processing was performed in the (E) Washing and fiber opening process, (F) Surface treatment process, and (G) Fiber opening process after surface treatment, all located on the same line. During this process, the line speed was set to 20 m / min and the glass cloth transport tension was set to 200 N. (E) In the cleaning and fiber opening process, the glass cloth is moved through water while an ultrasonic oscillator (product name: SERIES8500, manufactured by Branson) is used to generate waves at a frequency of 25 kHz and an output of 0.72 W / cm². 2 The glass cloth was first irradiated with ultrasound for 5 seconds, and then heated and dried at 130°C for 30 seconds to eliminate adhesion between the filaments. Next, in (F) the surface treatment process, the glass cloth was immersed for 3 seconds in a treatment solution in which 0.2% by mass of 3-methacryloyloxypropyltrimethoxysilane; OFS6030 (manufactured by Dow-Toray) was dispersed in pure water adjusted to pH=3 with acetic acid, then squeezed, and then dried at 125°C for 30 seconds. Next, in (G) the fiber opening process after surface treatment, a water pressure of 5.0 kgf / cm² was applied. 2 The glass cloth was opened using a columnar stream discharged from a high-pressure water spray, and then dried at 130°C for 30 seconds to obtain the glass cloth.

[0148] The glass cloth obtained above was impregnated with resin composition A, then passed through a slit with a width of 165 μm to scrape off excess resin composition, and dried in a drying oven at 120°C for 300 seconds to obtain a prepreg. This prepreg was cut to a size of 30 cm x 30 cm. Two prepregs were stacked, and copper foil (manufactured by Furukawa Electric Industry Co., Ltd., model: F2-WS, thickness: 12 μm) was then placed on both sides of the stacked prepregs. A metal-clad laminate was obtained by vacuum pressing. In this vacuum pressing process, the material was heated from room temperature at a heating rate of 2.0 °C / min under a vacuum pressure of 10 mmHg. After reaching a temperature of 40 °C, the pressure was increased to 40 kgf / cm² while continuing to heat. 2 The material was pressurized to achieve the desired temperature, and after reaching 200°C, the temperature was maintained at 200°C under atmospheric pressure for 60 minutes. Subsequently, the metal-clad laminate was processed under conditions of cooling to room temperature at a rate of 1.0°C / min.

[0149] (Examples 2-5, Comparative Example 1) As shown in Table 2, the metal-clad laminate was processed in the same manner as in Example 1, except that the resin composition was changed.

[0150] (Example 6) The surface treatment process (F) of the glass cloth was carried out with a treatment solution containing 0.3% by mass of N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride: Z6032 (manufactured by Toray Dow Corning Co., Ltd.) dispersed as a silane coupling agent. The resin composition F was used. In the vacuum pressing process, the glass cloth was heated from room temperature at a heating rate of 8.0°C / min under a vacuum pressure of 10 mmHg, and after reaching a temperature of 80°C, the pressure was increased to 10 kgf / cm² while continuing to heat. 2 The pressure was increased to the specified level, the temperature was maintained at 80°C for 8 minutes, and then the pressure was reduced to 40 kgf / cm². 2 The metal-clad laminate was processed in the same manner as in Example 1, except that it was processed under the same conditions as in Example 1, except that it was pressurized to such a degree, heated at a heating rate of 2.0°C / min, maintained at 195°C for 60 minutes under atmospheric pressure after reaching 195°C, and then cooled to room temperature at a cooling rate of 1.0°C / min.

[0151] (Example 7) The slit width used when processing the prepreg was set to 200 μm, and when processing the metal-clad laminate, the pressure applied after maintaining the temperature at 80°C for 8 minutes was set to 20 kgf / cm². 2Except for the points mentioned above, the metal-clad laminate was processed in the same manner as in Example 6.

[0152] (Example 8) (G) In the fiber opening process after surface treatment, the water pressure of the high-pressure water spray should be 1.0 kgf / cm². 2 Except for the points mentioned above, the metal-clad laminate was processed in the same manner as in Example 1.

[0153] (Example 9) (E) In the washing and fiber opening process, set the output of the ultrasonic irradiation to 0.07 W / cm². 2 Except for the points mentioned above, the metal-clad laminate was processed in the same manner as in Example 1.

[0154] (Example 10) (E) In the washing and fiber opening process, set the output of the ultrasonic irradiation to 0.07 W / cm². 2 (G) In the fiber opening process after surface treatment, the water pressure of the high-pressure water spray was set to 1.0 kgf / cm². 2 Except for the points mentioned above, the metal-clad laminate was processed in the same manner as in Example 1.

[0155] (Example 11) (E) In the cleaning and fiber opening process, set the output of the ultrasonic irradiation to 0.02 W / cm². 2 (G) In the fiber opening process after surface treatment, the water pressure of the high-pressure water spray was set to 0.5 kgf / cm². 2 Except for the points mentioned above, the metal-clad laminate was processed in the same manner as in Example 1.

[0156] (Example 12) (C) The metal-clad laminate was processed in the same manner as in Example 1, except that cleaning solution 2 was used in the heating and de-oiling process.

[0157] (Example 13) (C) The metal-clad laminate was processed in the same manner as in Example 1, except that cleaning solution 3 was used in the heating and de-oiling process.

[0158] (Example 14) Except for using glass yarns with an SiO2 content greater than 99.9% by mass, an average filament diameter of 5.0 μm, 200 filaments, and a twist count of 1.0 Z (T / m) as the warp and weft threads, and weaving the glass cloth fabric at a weaving density of 54 threads / inch for both warp and weft threads, the metal-clad laminate was processed in the same manner as in Example 1.

[0159] (Example 15) Except for using glass yarns with an SiO2 content greater than 99.9% by mass, an average filament diameter of 7.0 μm, 200 filaments, and a twist count of 1.0 Z (T / m) as the warp and weft threads, and weaving the glass cloth fabric at a weaving density of 60 threads / inch for the warp and 58 threads / inch for the weft, the metal-clad laminate was processed in the same manner as in Example 1.

[0160] (Comparative Example 2) Except for (E) the absence of ultrasonic irradiation in the cleaning and fiber opening process, and (G) the absence of fiber opening with high-pressure water spray in the fiber opening process after surface treatment, the metal-clad laminate was processed in the same manner as in Example 1.

[0161] (Comparative Example 3) The metal-clad laminate was processed in the same manner as in Example 1, except that the cooling rate was set to 5.0°C / min during the vacuum pressing process of the prepreg.

[0162] [Method for evaluating the loss tangent (tanδ) and glass transition temperature of resin substrates] The metal-clad laminate obtained above was etched to remove the copper foil from both sides of the laminate, thereby obtaining a resin substrate. The loss tangent of the resin substrate was measured using a rheometer. Specifically, the loss tangent value of the resin substrate at 200°C was determined by measuring a test piece cut from the resin substrate to a length of 30 mm and a width of 6.5 mm under the following measurement conditions.

[0163] <Measurement conditions> Instrument (Rheometer): ARES-G2 manufactured by TA Instruments Co., Ltd. Measurement conditions: Gap distance (initial value) 15mm (Axial force adjustment option), frequency 1Hz, measurement temperature 40~230℃, under air atmosphere, heating rate 5℃ / min, measurement interval 5 times / min, strain amount 0.05% (Auto strain adjustment option)

[0164] The glass transition temperature of the resin substrate was defined as the peak temperature of the loss tangent measured above.

[0165] [Method for evaluating the drill wear resistance of metal-clad laminates] Using the prepregs obtained above, metal-clad laminates for evaluating drill wear resistance were fabricated by stacking the prepregs to a total thickness of 1 mm and vacuum pressing. The vacuum pressing conditions were as described below. The resulting 1 mm thick metal-clad laminates were used to evaluate the drill wear resistance. The diameter reduction at a position 0.05 mm from the tip of the drill used for drilling holes in metal-clad laminates was measured using a diameter measuring machine OPTECH-MSP (manufactured by Union Tool Co., Ltd.). The diameter reduction (μm) was calculated by applying the following formula: Diameter reduction (μm) = Diameter of the drill before drilling (μm) - Diameter of the drill after drilling (μm). An ND-1A211 (manufactured by Via Mechanics Co., Ltd.) was used as the processing machine, and an MCWF V785GDC 0.15×2.9 (manufactured by Union Tool Co., Ltd.) was used as the evaluation drill. For the measurement sample, the resin substrate prepared as described above was used, with LE-R12H3 t0.18mm (manufactured by Mitsubishi Gas Chemical Co., Ltd.) as the entry board and PS-1160G t1.5mm (manufactured by Rishou Kogyo Co., Ltd.) as the backup board. Drilling was performed with a life of 30,000 hits, a rotation speed of 250krpm, a feed rate of 2.5m / min, a chip load of 10μm / rev, a sacrificial plate insertion depth of 0.3mm, and an upward speed of 25.4m / min.

[0166] The composition of the resin composition is shown in Table 1. Furthermore, the physical properties and performance evaluations of the resin substrates and other materials prepared in the examples and comparative examples are shown in Table 2. [Table 1]

[0167] Table 2-1

[0168] Table 2-2

Claims

1. Si content is SiO ２ A resin substrate comprising a glass cloth woven from glass threads in a range of 95% to 100% by mass, and a resin composition, The aforementioned glass cloth has a yarn width variation coefficient calculated using the formula: yarn width variation coefficient = yarn width standard deviation [μm] / yarn width [μm], where the value is within the range of 0.20 or less in both the warp and weft directions. A resin substrate having a loss tangent (tanδ) of 0.34 or less at 200°C.

2. The resin substrate according to claim 1, wherein the loss tangent (tanδ) at 200°C is in the range of 0.26 or less.

3. The resin substrate according to claim 1, wherein the loss tangent (tanδ) at 200°C is in the range of 0.20 or less.

4. The resin substrate according to claim 1, wherein the loss tangent (tanδ) at 200°C is in the range of 0.11 or less.

5. The resin substrate according to claim 1, wherein the tensile strength per unit thickness of the glass cloth is in the range of 0.8 N / 25 mm / μm or more in both the warp and weft directions.

6. The resin substrate according to claim 5, wherein the tensile strength per unit thickness of the glass cloth is in the range of 1.0 N / 25 mm / μm or more in both the warp and weft directions.

7. The resin substrate according to claim 1, wherein the dielectric loss tangent of the glass cloth at 10 GHz is in the range of 0.0015 or less.

8. The resin substrate according to claim 7, wherein the dielectric loss tangent of the glass cloth at 10 GHz is in the range of 0.0008 or less.

9. The resin substrate according to claim 7, wherein the dielectric loss tangent of the glass cloth at 10 GHz is in the range of 0.0004 or less.

10. The resin substrate according to claim 1, wherein the dielectric loss tangent of the resin composition at 10 GHz is in the range of 0.0045 or less.

11. The resin substrate according to claim 10, wherein the dielectric loss tangent of the resin composition at 10 GHz is in the range of 0.0035 or less.

12. The resin substrate according to claim 10, wherein the dielectric loss tangent of the resin composition at 10 GHz is in the range of 0.0030 or less.

13. The resin substrate according to claim 10, wherein the dielectric loss tangent of the resin composition at 10 GHz is in the range of 0.0025 or less.

14. The aforementioned glass cloth has an aperture ratio of 15.0% or less. The aforementioned aperture ratio is calculated using the following formula: The resin substrate according to claim 1, wherein the opening ratio [%] is calculated as follows: ((25400 / warp density [threads / inch] - warp width [μm]) × (25400 / weft density [threads / inch] - weft width [μm]) × 100) / ((25400 / warp density [threads / inch]) × (25400 / weft density [threads / inch])).

15. The resin substrate according to claim 14, wherein the aperture ratio of the glass cloth is in the range of 1.5% or more and 10.0% or less.

16. The resin substrate according to claim 14, wherein the aperture ratio of the glass cloth is in the range of 2.0% to 8.0%.

17. The resin substrate according to claim 1, wherein the resin composition comprises at least one resin selected from epoxy resins, radical polymerization curing resins, maleimidotriazine resins, thermosetting polyimide resins, bismaleimide resins, benzoxazine resins, cyclopentadiene / styrene copolymer resins, polyphenylene ethers, modified polyphenylene ethers, polyphenylene sulfides, polysulfones, polyethersulfones, polyarylates, aromatic polyamides, polyether ketones, polyether ether ketones, thermoplastic polyimides, insoluble polyimides, polyamide imides, cycloolefin resins, cyanate resins, and fluororesins.

18. The resin composition comprises an inorganic filler, as described in claim 1.

19. The resin substrate according to claim 1, wherein the glass transition temperature is in the range of 50°C or higher.

20. The resin substrate according to claim 1, wherein the volume fraction of the glass cloth in the resin substrate is in the range of 10% or more and 70% or less.

21. The resin substrate according to claim 1, wherein the number of layers of the glass cloth is 1 or more and 10 or less.

22. The resin substrate according to claim 1, wherein the coefficient of variation of the warp and weft threads of the glass cloth is in the range of 0.05 or more and 0.18 or less.

23. The resin substrate according to claim 22, wherein the coefficient of variation of the warp and weft threads of the glass cloth is in the range of 0.05 or more and 0.15 or less.

24. The resin substrate according to claim 22, wherein the coefficient of variation of the warp and weft threads of the glass cloth is in the range of 0.05 or more and 0.12 or less.

25. A metal-clad laminate comprising a resin substrate according to any one of claims 1 to 24, wherein the surface layer of the resin substrate is provided with metal foil on one or both sides.

26. A wiring board comprising a resin substrate according to any one of claims 1 to 24 and a wiring pattern for transmitting and receiving electrical signals.

27. An integrated circuit comprising a metal-clad laminate according to claim 25.

28. An integrated circuit comprising the wiring board described in claim 26.

29. An electronic device comprising the integrated circuit described in claim 27.

30. An electronic device comprising the integrated circuit described in claim 28.

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