Resin substrate, metal-clad laminate, and wiring board

Abstract

This resin substrate comprises: a glass cloth obtained by weaving glass yarns having an Si content in the range of 95-100 mass% in terms of SiO2; and a resin composition, wherein the glass cloth has a coefficient of variation in the yarn width in the range of at most 0.20 in both a warp direction and a weft direction, as calculated by the expression of coefficient of variation in yarn width=yarn width standard deviation [μm] / yarn width [μm], and the loss tangent (tanδ) at 200ºC is in the range of at most 0.34.

Description

Resin substrates, metal-clad laminates, and wiring boards

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

[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 the prepreg used as the insulating material for printed circuit boards, the glass cloth contained in the prepreg, and the glass yarn that makes 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 silicon dioxide (SiO ２ It is stated that the dielectric properties of metal-clad laminates and wiring boards are improved by using glass cloth having a content of 96.0% to 100.0% by mass.

[0005] By the way, in addition to dielectric properties, metal-clad laminates are required to be drillable. Various methods are known to improve the drill wear resistance when drilling holes in metal-clad laminates. For example, Patent Document 4 describes the SiO of glass cloth. ２By limiting the content to 70% or less, drill wear during drilling of printed circuit boards is suppressed. Furthermore, Patent Document 5 describes a metal-clad laminate that exhibits less drill wear during drilling by using a resin composition having a specific molecular structure. In addition, Patent Document 6 describes a laminate that exhibits less drill wear during drilling by reducing the particle size of the inorganic filler. Moreover, Patent Document 7 describes a method for significantly improving the drill wear resistance during drilling of laminates by using highly lubricating molybdenum compound particles as the inorganic filler.

[0006] International Publication No. 2019 / 065940, International Publication No. 2019 / 065941, Japanese Patent Publication No. 2021-63320, Japanese Patent Publication No. 2011-105554, Japanese Patent Publication No. 2007-224283, Japanese Patent Publication No. 2004-149577, Japanese Patent Publication No. 2016-147986

[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, and there was room for further improvement of dielectric properties. In this regard, Patent Document 3 describes SiO ２ It has been described that the dielectric properties of prepregs and printed circuit boards can be improved by using glass cloth made of glass filaments with a high composition content. However, as described in Patent Document 4, SiO ２ As the content increases, drill wear increases during the drilling process of printed circuit boards, reducing drilling efficiency and thus hindering the manufacturing of printed circuit boards. In order to improve the dielectric properties of printed circuit boards, SiO ２There is a strong desire for new methods to improve drill wear resistance even when using glass cloth with a 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, but it does not mention why the resin composition having a specific molecular structure improves drill wear resistance, and it has not been 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, but using an inorganic filler with a small average particle size tends to increase the viscosity of the varnish, which tends to reduce the productivity of the prepreg. Patent Document 7 discloses that drill wear can be suppressed by using molybdenum compound particles supported or coated with a molybdenum compound as an inorganic filler, as the molybdenum compound functions as a lubricant, but 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 is SiO ２ The objective is to provide resin substrates, metal-clad laminates, and wiring boards, etc., that contain glass cloth in a high content range of 95 to 100% by mass, and that can suppress drill wear during drilling.

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

[30] : [1] Si content is SiO ２A resin substrate comprising a glass cloth woven from glass yarn in the range of 95% to 100% by mass, and a resin composition, wherein the glass cloth has a coefficient of variation of yarn width calculated by the formula: Coefficient of variation of yarn width = Standard deviation of yarn width [μm] / Yarn width [μm], which is in the range of 0.20 or less in both the warp and weft directions, and the loss tangent (tanδ) at 200°C is in the range of 0.34 or less. [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 glass cloth has an aperture ratio of 15.0% or less, and the aperture ratio is calculated by the following formula: Aperture 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])) The resin substrate according to any one of [1] to

[13] .

[15] The resin substrate according to

[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

[14] , wherein the aperture ratio of the glass cloth is in the range of 2.0% or more and 8.0% or less.

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

[16] , wherein the resin composition comprises at least one resin selected from epoxy resin, radical polymerization curing resin, maleimide triazine resin, thermosetting polyimide resin, bismaleimide resin, benzoxazine resin, cyclopentadiene / styrene copolymer resin, polyphenylene ether, 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, and fluororesin.

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

[17] , wherein the resin composition comprises an inorganic filler.

[19] A resin substrate according to any one 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% to 70%.

[21] 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.

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

[21] , 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] A resin substrate according to any one of [1] to

[21] , 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] 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.

[25] A metal-clad laminate comprising a resin substrate according to any one 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 according to any one of [1] to

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

[27] An integrated circuit comprising the metal-clad laminate according to

[25] .

[28] An integrated circuit comprising the wiring board according to

[26] .

[29] An electronic device comprising the integrated circuit according to

[27] .

[30] An electronic device comprising the integrated circuit according to

[28] .

[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.

[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 has a Si content of SiO ２A glass cloth (hereinafter referred to as the glass cloth of the present disclosure) formed by weaving glass fibers in the range of 95% to 100% by mass in terms of conversion, and a resin substrate containing a resin composition. The glass cloth of the present disclosure has a coefficient of variation in yarn width calculated by the formula: coefficient of variation in yarn width = standard deviation of yarn width [μm] / yarn width [μm], and the value of the coefficient of variation in yarn width is in the range of 0.20 or less in both the warp direction and the weft direction. And the loss tangent (tanδ) of the resin substrate of the present disclosure at 200 ° C is in the range of 0.34 or less.

[0014] As a result of the studies conducted by the present inventors, it has been found for the first time that the viscoelastic properties of the resin substrate, which have not been focused on so far, have a great influence on the drill wear resistance. Specifically, during drill processing, the temperature of the laminated board processing part rises to about 200 ° C, but it has been clarified that the lower the loss tangent (tanδ) of the laminated board during processing, the more effective it is in suppressing the wear of the high heat-resistant drill treated with diamond coating. In addition, the present inventors uniformly opened the quartz glass cloth and adjusted the coefficient of variation in yarn width of the glass cloth to 0.20 or less, so that the number of locations where the quartz glass yarn bundle with high hardness is localized with respect to the drill progress direction is reduced, and the drill wear resistance of the metal-clad laminate can be further improved. By using a resin substrate containing a glass cloth with a coefficient of variation in yarn width of 0.20 or less and having a loss tangent (tanδ) of 0.34 or less at a temperature (in one aspect, the cutting temperature) of ２ 200 ° C, it has become possible to suppress the outer peripheral wear of the drill of the metal-clad laminate containing a glass cloth with an SiO ２ content of 95% by mass or more.

[0015] [Glass fiber] The glass fiber constituting the glass cloth of the present 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 SiO ２ conversion. From the viewpoint of the dielectric properties of the glass fiber, the Si content is more preferably 99.0% to 100% by mass, still more preferably 99.5% to 100% by mass, and particularly preferably 99.9% to 100% by mass. By using the glass fiber with the above Si content, it is possible to reduce the dielectric tangent of the glass cloth. Quartz glass has a lower SiO ２Due to its high content and hardness, it was found that using glass cloth composed of 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] [Overall composition of glass cloth] [Weaving structure of glass cloth, etc.] Glass cloth is composed of glass yarn (for example, glass yarn made of multiple glass filaments) as warp and weft threads. Examples of weaving structures of 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, and particularly preferably 50 g / m² ２The 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 width of the warp and weft threads of the glass cloth is 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 thread 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 width of the warp and weft threads of the glass cloth is measured by the method described in the example.

[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 threads 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 the opening ratio of the glass cloth calculated using the following formula is effective for evaluating whether the glass cloth is sufficiently opened: 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]))

[0023] The aperture ratio can be adjusted by opening the glass cloth fibers, and glass cloth that has been sufficiently opened tends to have a small aperture ratio. From the viewpoint of improving drill wear resistance, the aperture 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 aperture 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 aperture 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, since quartz glass has a higher hardness than glass other than quartz glass, it is known that conventional fiber opening treatments do not open it sufficiently and uniformly. As a method for reducing the aperture ratio of quartz glass cloth, it is preferable to perform ultrasonic and high-pressure water spraying as fiber opening treatments, as described later. By performing ultrasonic and high-pressure water spraying during the fiber-opening process, it becomes easier to sufficiently open the fibers of the glass cloth. Although not particularly limited, the opening ratio of the glass cloth of this disclosure may 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 Fiber Width of Glass Cloth] The standard deviation of fiber width of glass cloth is preferably in the range of 80 μm or less in both the warp and weft directions, more preferably in the range of 70 μm or less, even more preferably in the range of 60 μm or less, even more preferably in the range of 50 μm or less, and particularly preferably in the range of 40 μm or less. If the standard deviation of fiber width is within the above range, it is easy to adjust the coefficient of variation of fiber width of the glass cloth to a predetermined range, and the effect of improving drill wear resistance is easily obtained. Although not particularly limited, the standard deviation of fiber width of glass cloth may be 1 μm or more in both the warp and weft directions. The standard deviation of fiber width of glass cloth can be controlled by the ultrasonic output and spray water pressure in the fiber opening process. The standard deviation of fiber width of glass cloth in this disclosure is measured by the method described in the examples.

[0025] [Coefficient of variation of fiberglass cloth thread width] In one embodiment of the fiberglass cloth of this disclosure, the coefficient of variation of the fiberglass cloth thread width 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 warp and weft threads of the fiberglass cloth contained in the metal-clad laminate, the fewer locations there are where bundles of quartz glass threads 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 threads of the fiberglass cloth thread width 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 warp and weft threads of the glass cloth of this disclosure is measured by the method described in the examples.

[0026] [Dielectric Loss Tangent of Glass Cloth] The dielectric loss tangent of 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 the printed circuit board. 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 is easier to improve the dielectric properties of the printed circuit board. Although not particularly limited, the dielectric loss tangent of glass cloth at 10 GHz in this disclosure may be 0.00005 or more. The dielectric loss tangent of 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 Warp and Weft Directions] The tensile strength of the glass cloth in the warp and weft directions of the glass cloth of 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 of the glass cloth in the warp and weft directions is 16 N / 25 mm 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. 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 in the heating and de-oiling process is sufficiently suppressed, and the increase in hardness of the glass is suppressed by reducing the crystalline component in the glass, so drill wear can be suppressed. Although not particularly limited, the tensile strength of the glass cloth in the warp and weft directions of the glass cloth of this disclosure may be 400 N / 25 mm or less. The tensile strength of the glass cloth in the warp and weft directions of the glass cloth of this disclosure is 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 Thickness of Glass Cloth] The tensile strength per 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 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 thickness of the glass cloth of this disclosure is measured by the method described in the examples.

[0030] [Method for Evaluating the Dielectric Loss Tangent of Glass Cloth and Resin Substrate] The dielectric properties of the glass cloth and resin substrate of this disclosure can be measured using the resonance method. A preferred measuring instrument for the resonance method is a split-cylinder resonator. The resonance method allows for simpler and more accurate measurements compared to conventional measurement methods that use printed circuit boards as measurement samples and evaluate their dielectric properties. This is because, although not limited to theory, the resonance method is suitable for evaluating low-loss materials in the high-frequency range.

[0031] The measurable range of a measuring instrument for the dielectric properties of glass cloth and resin substrates applicable to printed circuit boards, particularly printed circuit boards for high-speed communication, is preferably within a suitable range for both the frequency dielectric constant (Dk) and the dielectric loss tangent (Df). For example, Dk is preferably 1.1 to 50, more preferably 1.51 to 10, and even more preferably 2.0 to 5. Df may be greater than 0, and is preferably 1.0 × 10. －６ The above 1.0 x 10 －１ More preferably, 1.0 × 10 －５ The above 5.0 x 10 －２ More preferably 5.0 × 10 －５ The above 1.0 x 10 －２ The following applies:

[0032] The measuring instrument's measurable frequency is preferably 10 GHz or higher. A frequency of 10 GHz or higher allows for characteristic evaluation in the frequency band range expected when the glass cloth is actually used in printed circuit boards for high-speed communication.

[0033] The lower limit of the measurement area is preferably 10 mm. ２ More specifically, 15 mm ２ More preferably 20 mm ２ That concludes the explanation. Also, the upper limit for the measurement area is 45 m². ２ The following is acceptable.

[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 the resin composition] A thermosetting resin or a thermoplastic resin can be used as the matrix resin in the resin composition. 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 pyrolysis-type catalyst or a photodegradation-type 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 an inorganic filler. The inorganic filler is 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. The inorganic filler may be used alone or in combination of two or more types. From the viewpoint of suppressing drill wear, the content of the inorganic filler 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 the inorganic filler 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 the present disclosure within a predetermined range. From the viewpoint of controlling the loss tangent of the resin substrate of the present disclosure within a predetermined range, the elastomer content relative to the modified polyphenylene ether content in the resin composition containing 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 content of the 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 content of the crosslinking agent relative to the content 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 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 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 types.

[0047] [Method for Evaluating the Dielectric Loss Tangent of a Resin Composition] The dielectric loss tangent of a resin composition can be measured by preparing a resin composition film and using the resonance method. The method for evaluating the dielectric loss tangent of a resin composition film is preferably 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 composition 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 in the resin substrate] The number of glass cloth layers 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 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 that has little 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. As a result of the inventors' investigation, it was found that the smaller the loss tangent of the resin substrate, the more the drill wear is suppressed in a diamond-coated drill. When cutting a resin substrate with a drill, it is first necessary to elastically deform the resin. It was found that 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 revealed 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 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. It was revealed that reducing the amorphous component in the resin is effective in lowering the loss coefficient of the resin substrate. Specifically, by making the cooling rate during resin curing slower than conventional methods, the amorphous component in the resin can be reduced, resulting in a resin substrate with a small loss tangent. This allows for a Si content of SiO ２ Even a resin substrate made using glass cloth woven from high-hardness glass threads with a hardness in the range of 95% to 100% by mass can have excellent drill wear resistance.

[0056] [Glass Transition Temperature of Resin Substrate] 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. Metal-clad laminates and wiring boards obtained using the resin substrate of this disclosure are excellent in various properties.

[0058] [Integrated Circuits and Electronic Devices] The present disclosure also provides integrated circuits including the metal-clad laminate or the wiring board, and electronic devices including the integrated circuits. Integrated circuits and electronic devices obtained using the resin substrates of the present 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 plurality of filaments and has a Si content of SiO ２ The present invention includes a step of weaving glass yarn, which is in the range of 95% to 100% by mass in terms of conversion, as warp and weft threads to obtain glass cloth (weaving step: B). The present invention also includes a step of aligning and flattening the glass yarn before the weaving step, and then applying a sizing agent (warping step: A), a step of washing the glass yarn before heat de-oiling with water at 50°C or higher after the warping step, and before, during, or after the weaving step (pre-heat de-oiling washing step: C), a step of reducing the binder adhering to the glass yarn 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 of glass yarn (A)] The warping process of glass yarn involves a Si content of SiO ２The process includes using glass yarn in the range of 95% to 100% by mass (converted to glass yarn), 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 yarn bundle is not particularly limited, but examples include processing by pressing with a roll. From the viewpoint of flattening the yarn bundle while suppressing fluff, the pressing is preferably 1.0 kgf / cm. ２ ~6.0kgf / cm ２ More preferably 2.0 kgf / cm² ２ ~5.5kgf / cm ２ More preferably 2.5 kgf / cm² ２ ~5.0kgf / cm ２ That is the case.

[0062] [Weaving process of glass cloth raw material (B)] The weaving process of glass cloth raw material involves multiple filaments and a Si content of SiO ２ The invention includes weaving glass yarn, which is in the range of 95% to 100% by mass when converted, as both 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 de-oiling washing step (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 due to the adhesive on the filaments and the combustion residue of the adhesive during heating de-oiling, and allows control so that the fiber width variation coefficient and opening ratio of the glass cloth 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, it is possible to wash away excess adhesive while leaving the amount of adhesive necessary to protect the glass fibers until the heating de-oiling step. 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 glass cloth surface is controlled within a predetermined range, even if the glass cloth is heated and de-oiled at high temperatures, a significant decrease in the tensile strength of the glass cloth due to the devitrification phenomenon of quartz glass can be suppressed. Furthermore, in order to suppress the devitrification phenomenon, if the glass cloth is washed with a solvent that has a low amount of Na ions and / or Mg ions before heating and de-oiling, the amount of Na ions and / or Mg ions on the glass surface decreases, making it possible to suppress the devitrification phenomenon of quartz glass even when heating and de-oiling at high temperatures. Maintaining the strength of the glass cloth after heating and de-oiling makes it easier to control tension in subsequent processing steps, and as a result, cutting and other damage can be suppressed.

[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 cleaning solution for the glass cloth is a solvent in which the amount of Na ions and / or Mg ions is controlled to predetermined levels, as shown below. Here, the numerical value (ppm) for the amount of ions in the cleaning solution indicates the amount of ions 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, thereby making 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 sodium ions in the cleaning 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 glass cloth surface, thereby making 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 cleaning solution is measured by the method described in the examples.

[0068] From the perspective of minimizing the decrease in the tensile strength of glass cloth, the solvent used for washing glass cloth is SO ４ It is preferable that the solvent has an ion content controlled to a predetermined amount. ４By cleaning the glass cloth with a cleaning solution of a certain ionic concentration, the ions on the surface of the glass cloth can be transferred to the cleaning solution, and the ions in the cleaning solution can be transferred to and adhered to the surface of the glass cloth.

[0069] SO2 cleaning solution ４ The ion content 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. ４ If the ion amount is 18 ppm or less, SO2 will adhere to the glass cloth surface. ４ By making it easier to reduce the amount of ions, the devitrification phenomenon of quartz glass when heated and de-oiled at high temperatures (for example, 600°C to 1500°C) is suppressed, and as a result, it is easier to ensure the tensile strength of the glass cloth. Note that the cleaning solution is SO ４ The amount of ions is measured by the method described in the examples.

[0070] A means of cleaning the glass cloth to reduce the amount of ions adhering to the glass cloth surface can reduce Na ions and / or Mg ions on the glass cloth surface, preferably SO ４ A method that can further reduce ions is acceptable. For example, methods using ultrasound (e.g., methods using ultrasonic transducers), spraying (e.g., spraying with high-pressure spray), and water vapor atomization can be considered. From the viewpoint of inexpensive processing, a cleaning solution (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 SO4) can be used. ４ A preferred method involves immersing the glass cloth in a tank containing a solvent with an ion content of 18 ppm or less, removing excess cleaning solution with a squeeze roller or the like, and then drying the glass cloth. The immersion time for the glass cloth can be, for example, 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, more preferably water with a Na ion content of 20 ppm or less and / or a Mg ion content of 18 ppm or less, and more preferably water with a Na ion content of 20 ppm or less and / or a Mg ion content of 18 ppm or less and / or SO ４ Water with an ion content of 18 ppm or less is even more preferable. Na ion content of 20 ppm or less and / or Mg ion content of 18 ppm or less and / or SO ４ The method for producing water with an ion content of 18 ppm or less may be a known method. For example, methods such as filtration using an RO membrane, deionization using an ion exchange resin, and distillation are possible. The solvent used in the washing solution may contain other liquid components (liquids other than water, etc.) as long as they do not hinder the effects of this disclosure. The solvent may also be a lower alcohol (methanol, etc.), or a mixture of water and a lower alcohol.

[0072] [Heating De-oiling Process (D)] In the heating de-oiling process (D) of the glass cloth, heating the glass yarn reduces the amount of sizing agents and their residues, as well as modified substances thereof, that may be arbitrarily attached to the glass yarn, and preferably removes them. By performing the heating de-oiling process, 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 means (heating means, heating medium, heating mechanism, heating device, and heating component, etc.) can be used as means for heating de-oiling.

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

[0074] In the heat de-oiling process, heating raw glass cloth, where the softening point of the glass fibers is 900°C or higher, in a temperature range of 600°C to 1600°C makes it easier to suppress 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. When the heat de-oiling temperature is 600°C or higher, it is easier to effectively remove sizing agents and the like adhering to the glass cloth, making it easier to produce glass cloth with excellent dielectric properties. When the heat de-oiling 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 heat de-oiling process is not limited to the above. As a further form of the heat de-oiling process, for example, a method is known in which the heating amount, expressed as a heating temperature (°C) of 100°C or higher × heating time (h), 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 100 to 600°C).

[0079] <Heating means> Examples of heating means include heating furnaces, electric heaters, and burners, with gas-powered single-radiant tube burners or electric heaters being preferred. Multiple different heating means 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 for applying steam> Means for heating the glass cloth (means for applying steam) may include spraying, showering, and using jet nozzles. 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 process (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 process (E) preferably includes an opening process in which the glass cloth is irradiated 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 surface treatment (G), the glass cloth is more easily opened adequately and uniformly, and the fiber width variation coefficient and opening ratio can be controlled to meet predetermined ranges. If the fiber width variation coefficient and opening ratio are within predetermined ranges, 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 drill travel, making it easier to obtain the effect of improving the drill wear resistance of 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 is preferred in which the fiberglass cloth is conveyed roll-to-roll using a device having an unwinding mechanism and a winding mechanism.

[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 preferable. Furthermore, from the viewpoint of safety, a temperature of 60°C or lower is preferable 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 30 N to 500 N per 1 m of glass cloth width. When the line tension acting on the warp threads is 30 N per 1 m 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 the glass cloth fibers by ultrasonic irradiation, ultrasound with a frequency of 20 kHz to 200 kHz can be used. The ultrasonic frequency is preferably 20 kHz to 50 kHz, and more preferably 20 kHz to 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 / cm 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 the glass cloth by ultrasonic irradiation, an ultrasonic output of 0.02 W / cm is preferred. ２ The above is preferable, and 0.04 W / cm² ２ The above is more preferable, 0.07 W / cm² ２ The above is even more preferable, 0.14 W / cm² ２ The above is even more preferable, 0.21 W / cm² ２ The above is particularly preferable. For opening the glass cloth fibers by ultrasonic irradiation, an ultrasonic output of 3.60 W / cm² is recommended. 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 0.5 seconds or more and 60 seconds or less. An ultrasonic treatment time of 0.5 seconds or more is preferable because it allows for good fiber separation of the glass cloth or its intermediates. A longer ultrasonic treatment time is preferable because it yields a greater fiber separation effect, but since there is almost no further fiber separation 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. A dissolved oxygen content of 1 ppm or more is preferred in the liquid used in ultrasonic cleaning to ensure uniform fiber opening. A dissolved oxygen content of 20 ppm or less is preferred because it provides a good fiber opening effect to the textile. A dissolved oxygen content of 1 ppm to 20 ppm is preferred because it provides a uniform and good fiber opening effect.

[0097] [Surface treatment step (F) of glass cloth] The surface treatment step (F) of applying a surface treatment agent 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 treatment method according to this embodiment, or it may be provided in between.

[0098] The process of applying the surface treatment agent may include, for example, a coating step 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, and a fixing step in which the silane coupling agent is fixed to the surface of the glass by heat drying. Performing the surface treatment step (F) makes it easier to suitably surface treat the glass cloth.

[0099] Possible methods for applying the processing solution to the glass cloth in the coating process include (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 (for example, 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. If the concentration of the treatment solution is within the predetermined range, the glass cloth will be more easily and favorably surface-treated. The immersion time in the treatment solution is preferably 0.5 seconds to 1 minute, more preferably 1 second to 30 seconds. If the immersion time in the treatment solution is within the predetermined range, the glass cloth will be more easily and favorably 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] As a process to reduce the silane coupling agent, at least one of the following steps may be performed: a washing step to wash away silane coupling agents that did not form chemical bonds with the surface of the glass cloth; a drying step to heat and dry the glass cloth after washing; and a final washing step to reduce any remaining unwanted components that did not form chemical bonds with the surface of the glass cloth. By performing a process to reduce the silane coupling agent, it becomes easier to control the ignition loss of the glass cloth. The process to reduce the silane coupling agent may include, for example, a final drying step after the final washing step.

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

[0104] In the final cleaning process, 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 linear 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.

[0105] Organic solvents with high affinity for residues or modified products of silane coupling agents include alcohols such as methanol, ethanol, and butanol; ketones such as acetone and 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. Among these, aromatic hydrocarbons, alcohols, or ketones are preferred, with methanol being more preferred, from the viewpoint of efficiently reducing silane coupling agents physically adhering to the glass cloth. Therefore, it is preferable to use a cleaning solution 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) as the cleaning solution in the final cleaning process.

[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 (G) after surface treatment] As for the process (G) of opening at least a portion of the glass filaments bonded by the 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 ２ The above is 5.0 kgf / cm². ２The 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] 《Method for Manufacturing Prepregs》 The method for manufacturing prepregs is not limited and publicly known techniques can be used. For example, one method is to impregnate the glass cloth with the resin composition and then dry and remove 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 used. 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 used.

[0115] 《Method for Processing Metal-Clad Laminates》 The method for processing metal-clad laminates 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] For heating and pressurizing, for example, a multi-stage press, vacuum press, multi-stage vacuum press, continuous molding, and autoclave molding machine can be used. 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 pressurizing pressure during heating and pressurizing is preferably 10 to 80 kgf / cm², from the viewpoint of sufficiently curing the resin. ２ A range of 20 to 60 kgf / cm² is preferred. ２ The range is, more preferably, 30 to 50 kgf / cm². ２ It is within the range of [the specified range].

[0117] Heating and pressurizing can be carried out, 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 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 heating and pressurizing maintenance time 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 achieve a loss tangent of 0.34 or less for the resin substrate, the cooling rate after heating and pressurizing is set to a range of 0.5 to 3.0°C / min. By performing the cooling at a slower rate 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, reducing the productivity of the resin substrate and metal-clad laminate. 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] 《Method for Processing Resin Substrates》 The method for processing resin substrates is not limited and known techniques can be used. For example, one method is to remove copper foil from the above-mentioned metal-clad laminate by etching with an iron(III) chloride aqueous solution.

[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] 45.0 parts by mass of toluene as a solvent was mixed with 44.0 parts by mass of modified polyphenylene ether (trade name: SA-9000, manufactured by SABIC Innovative Plastics Co., Ltd.) and 5.4 parts by mass of silica filler (trade name: CRS1057 EXR-3F, ​​manufactured by Ryusen Co., Ltd.). 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 (trade name: Perbutyl P, manufactured by NOF Corporation) were added to the solution as radical polymerizable compounds, and the mixture was thoroughly stirred to obtain resin composition A.

[0123] [Method for preparing resin composition B] Resin composition B 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 (trade name: SA-9000, manufactured by SABIC Innovative Plastics Co., Ltd.), 0.6 parts by mass of elastomer (trade name: ToughTec H1041, manufactured by Asahi Kasei Corporation), and 5.4 parts by mass of silica filler (trade 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 (trade 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 C.

[0125] [Method of compounding resin compositions D to E and G] The compounding was carried out in the same manner as for resin composition C, except that the compounding 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 at 100°C for 30 minutes in a nitrogen-flow forced-air dryer (product name: DN411I, manufactured by Yamato Scientific Co., Ltd.). The dried film was cured at 200°C for 90 minutes using the nitrogen-flow forced-air dryer to obtain a resin composition film containing cured resin composition material. The thickness of the obtained resin composition film was determined using a micrometer (product name: MDC-25PX, manufactured by Mitutoyo Corporation). The spindle of the micrometer was gently rotated and lightly brought into contact with the measuring surface of the resin composition film parallel to it, and the scale was read after the ratchet clicked three times.

[0128] 《Measurement Method》 [Evaluation Method for 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 glass cloth were determined by 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 yarn width of 250 warp (or weft) threads was randomly measured, and the average value, yarn width standard deviation, and yarn width variation coefficient of the obtained 250 warp (or weft) threads were calculated. The yarn width variation coefficient was calculated using the formula: Yarn width variation coefficient = Yarn width standard deviation [μm] ÷ Yarn width average [μm].

[0129] [Method for Evaluating the Opening Ratio of Glass Cloth] Using the yarn width obtained by the above method, the opening ratio of the glass cloth was determined according to the formula: Opening ratio [%] = ((25400 / warp yarn density [threads / inch] - warp yarn width [μm]) × (25400 / weft yarn density [threads / inch] - weft yarn width [μm]) × 100) / ((25400 / warp yarn density [threads / inch]) × (25400 / weft yarn 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 made three clicks.

[0131] [Method for evaluating the basis weight (mass of the cloth) of glass cloth] The mass was determined by cutting the glass cloth to a predetermined size and dividing its mass 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 Equivalent Thickness of Glass Cloth] Glass cloth is a discontinuous planar material with air between the glass fibers. Therefore, the equivalent 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] The dielectric loss tangent of glass cloth and resin composition films at 10 GHz was determined in accordance with IEC 62562. 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 films, 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 / 25 mm) 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 / 25 mm / 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 method described above to the formula: Tensile strength of glass cloth (N / 25 mm) / Thickness of glass cloth (μm).

[0136] [Method for preparing resin substrates] Resin substrates were 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 to obtain 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 a 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 the resin substrate] Using a micrometer, the spindle was rotated gently 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 made three clicks.

[0139] [Method for evaluating the volume fraction of glass cloth contained in a resin substrate] The volume fraction of glass cloth contained in a 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 resin substrates at 10 GHz was determined in accordance with IEC 62562. Specifically, the dielectric loss tangent was measured for 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). Measurements were performed five times for each sample, and the average value was calculated. The thickness of the resin substrate determined above was used as the thickness of each sample.

[0141] [Amount of Na ions, Mg ions, and SO in the washing solution] ４ [Measurement of Ion Content] The amount of Na ions, Mg ions, and SO in the washing solution used to wash the glass cloth before heating and degreasing. ４ The amount of ions was measured using ion chromatography under the following conditions.

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

[0143] <Cation Ion Chromatography Conditions> Apparatus: Tosoh IC-2010 Separation Column: Tosoh TSKgel-Super IC-Cation / P (4.6 mm x 150 mm) Separation Solution: 2.5 mM HNO ３ +0.5 mM L-histidine Flow rate: 1.0 mL / min Detection: Electrical conductivity Column temperature: 40°C Injection volume: 30 μL

[0144] <Anion Ion Chromatography Conditions> Instrument: Tosoh IC-2010 Separation Column: Tosoh TSKgel-Super IC-AZ (4.6 mm x 150 mm) Eluent: 6.3 mM NaHCO3 ３ +1.7 mM Na ２ CO ３ Flow rate: 0.8 mL / min Detection: Electrical conductivity Column temperature: 40°C Injection volume: 30 μL

[0145] [Cleaning solutions 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. Cleaning solution 1: Na ions = 1.6 ppm, Mg ions = 0 ppm, SO ４ Ions = 0 ppm Washing solution 2: Na ions = 2.5 ppm, Mg ions = 0.1 ppm, SO ４ Ions = 0.5 ppm Washing solution 3: Na ions = 0 ppm, Mg ions = 0 ppm, SO ４ Ions = 0 ppm

[0146] (Example 1) SiO ２Using a glass yarn with a content of more than 99.9% by mass, an average filament monofilament diameter of 5.0 μm, 100 filaments, and a twist number of 1.0 Z (T / m), (A) the warping process of the warp yarns was carried out. At this time, the warped warp yarns aligned at a conveying speed of 60 m / min were nipped with a roll at a load of 3.0 kgf / cm ２ to flatten the glass yarn. Then, a sizing agent mainly composed of polyvinyl alcohol (PVA) resin was attached by the following procedure. That is, an aqueous solution with a concentration of 5% by mass of PVA (trade name: PVA403, manufactured by Kuraray Co., Ltd.) was prepared, and 2% by mass of hydrogenated castor oil was blended as a lubricant in this aqueous solution to obtain a sizing agent. The sizing agent kept at 60 °C was attached to the glass yarn and then dried to perform sizing treatment. Then, using an air jet loom, a glass cloth fabric was woven at a weaving density of 66 warp yarns / inch and 68 weft yarns / inch. As the weft yarn, a glass yarn with an average filament monofilament diameter of 5.0 μm, 100 filaments, and a twist number of 1.0 Z (T / m) was used.

[0147] The obtained glass cloth fabric was conveyed at a line speed of immersing it in a water tank storing cleaning liquid 1 at 60 °C for 15 seconds while cleaning the sizing agent adhering to the glass surface ((C) pre-heating degreasing cleaning process). Then, in a heating furnace provided on the same line, it was heated at atmospheric pressure at 1000 °C for 15 seconds by the Roll-to-Roll method to perform (D) the heating degreasing process. Using the glass cloth after heating degreasing, continuous processing was carried out in (E) the cleaning and fibrillating process, (F) the surface treatment process, and (G) the fibrillating process after surface treatment provided on the same line. At this time, the line speed was 20 m / min, and the conveying tension of the glass cloth was set to 200 N for processing. In (E) the cleaning and fibrillating process, while the glass cloth was running in water, a frequency of 25 kHz and an output of 0.72 W / cm were generated by an ultrasonic oscillator (product name: SERIES8500, manufactured by Branson) ２The 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 / cm 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] After impregnating the glass cloth obtained above with resin composition A, the excess resin composition was scraped off by passing it through a slit with a slit width of 165 μm, and the material was 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 of the obtained 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, and 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, and after reaching a temperature of 40°C, the pressure was increased to 40 kgf / cm 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, metal-clad laminates were processed in the same manner as in Example 1, except that the resin composition was changed.

[0150] (Example 6) A treatment liquid in which 0.3% by mass of the hydrochloride of N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane: Z6032 (manufactured by Toray Dow Corning Co., Ltd.) is dispersed was used to perform the surface treatment step (F) of the glass cloth, and the resin composition F was used. In the vacuum press step, heating was carried out from room temperature at a heating rate of 8.0 °C / min under a vacuum of 10 mmHg. After reaching a temperature of 80 °C, while continuing to heat, the pressure was increased to 10 kgf / cm ２ and the pressure was maintained at 80 °C for 8 minutes. Then, the pressure was increased to 40 kgf / cm ２ and heating was carried out at a heating rate of 2.0 °C / min. After the temperature reached 195 °C, the temperature was maintained at 195 °C for 60 minutes under atmospheric pressure, and then the metal-clad laminate was processed under the condition of cooling to room temperature at a cooling rate of 1.0 °C / min in the same manner as in Example 1 except for the above points.

[0151] (Example 7) The metal-clad laminate was processed in the same manner as in Example 6 except that the slit width during prepreg processing was set to 200 μm and the pressure for pressurization after maintaining the temperature at 80 °C for 8 minutes during metal-clad laminate processing was set to 20 kgf / cm ２ .

[0152] (Example 8) The metal-clad laminate was processed in the same manner as in Example 1 except that the water pressure of the high-pressure water spray in the fiber opening step after surface treatment (G) was set to 1. kgf / cm ２ .

[0153] (Example 9) The metal-clad laminate was processed in the same manner as in Example 1 except that the output of ultrasonic irradiation in the washing and fiber opening step (E) was set to 0.07 W / cm ２ .

[0154] (Example 10) The points where the output of ultrasonic irradiation in the washing and fiber opening step (E) was set to 0.07 W / cm ２ and the water pressure of the high-pressure water spray in the fiber opening step after surface treatment (G) was set to 1. kgf / cm ２ The metal-clad laminate was processed in the same manner as in Example 1 except for the above points.

[0155] (Example 11) (E) In the cleaning and fiber opening process, the output of the ultrasonic irradiation was set to 0.02 W / cm 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 step.

[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 step.

[0158] (Example 14) As warp and weft, SiO ２ Except for using glass yarn with a 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), and weaving the glass cloth fabric with a weave density of 54 warp threads / inch and 54 weft threads / inch, the metal-clad laminate was processed in the same manner as in Example 1.

[0159] (Example 15) As warp and weft, SiO ２ Except for using glass yarn with a 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), and weaving the glass cloth fabric with a weave density of 60 warp threads / inch and 58 weft threads / inch, the metal-clad laminate was processed in the same manner as in Example 1.

[0160] (Comparative Example 2) The metal-clad laminate was processed in the same manner as in Example 1, except that (E) ultrasonic irradiation was not performed in the cleaning and fiber-opening process, and (G) high-pressure water spray fiber-opening was not performed in the fiber-opening process after surface treatment.

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

[0162] [Method for Evaluating the Loss Tangent (tanδ) and Glass Transition Temperature of Resin Substrates] A resin substrate was obtained by etching the metal-clad laminate obtained above to remove the copper foil from both sides of the metal-clad laminate. 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> Equipment (Rheometer): ARES-G2 manufactured by TA Instruments Co., Ltd. Measurement conditions: Gap distance (initial value) 15 mm (Axial force adjustment option), frequency 1 Hz, measurement temperature 40-230°C, under air atmosphere, heating rate 5°C / 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 drill wear resistance was evaluated using the obtained 1 mm thick metal-clad laminates. The diameter reduction at a position of 0.05 mm from the tip of the drill used to drill holes in the metal-clad laminate was calculated using a diameter measuring machine OPTECH-MSP (Union Tool Co., Ltd.) by applying the formula: Diameter reduction (μm) = Diameter of the drill before drilling (μm) - Diameter of the drill after drilling (μm). An ND-1A211 (Via Mechanics Co., Ltd.) was used as the processing machine, and an MCWF V785GDC 0.15×2.9 (Union Tool Co., Ltd.) was used as the evaluation drill. For the measurement samples, the resin substrate prepared as described above was used, with LE-R12H3 t0.18 mm (manufactured by Mitsubishi Gas Chemical Co., Ltd.) as the entry board and PS-1160G t1.5 mm (manufactured by Rishou Kogyo Co., Ltd.) as the backup board. Hole drilling was performed with a life of 30,000 hits, a rotation speed of 250 krpm, a feed rate of 2.5 m / min, a chip load of 10 μm / rev, a sacrificial plate insertion depth of 0.3 mm, and an upward speed of 25.4 m / 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.

[0167]

[0168]

Claims

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

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 resin substrate according to claim 1, wherein the glass cloth has an aperture ratio of 15.0% or less, and the aperture ratio is calculated by the following formula: Aperture 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])).

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% or more and 8.0% or less.

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 substrate according to claim 1, wherein the resin composition comprises an inorganic filler.

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 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 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. 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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