Glass yarn, glass cloth, prepreg, and printed wiring board

Abstract

A glass cloth composed of glass filaments, wherein the silicon (Si) content in the glass filaments is 95.0 to 100% by mass in terms of silicon dioxide (SiO 2 ) and the snarl index of the glass filaments is 400 mm or less. Alternatively, the bulk dielectric tangent of the glass constituting the glass filaments at 10 GHz is in the range of 0.001 or less, and the snarl index of the glass filaments is 400 mm or less.

Description

Technical Field

[0001] The present disclosure relates to glass yarns, glass cloths, prepregs, printed wiring boards, and the like.

Background Art

[0002] Currently, the performance of information terminals such as smartphones is improving, and high-speed communication represented by 5G communication is progressing. Along with such a background, not only an improvement in heat resistance that has been conventionally required for printed wiring boards for high-speed communication, but also a further improvement in dielectric properties (for example, lowering of the dielectric tangent) of the insulating material is desired. Similarly, improvement in dielectric properties is desired for prepregs used as insulating materials for printed wiring boards, glass yarns included in the prepregs, glass cloths, and the like.

[0003] In order to reduce the dielectric constant of insulating materials, a method of forming an insulating material using a prepreg in which a low-dielectric resin (hereinafter referred to as a "matrix resin") is impregnated into glass cloth is known (for example, Patent Documents 1 and 2). Patent Documents 1 and 2 describe that polyphenylene ether end-modified with a vinyl group or a methacryloxy group is advantageous in terms of low dielectric properties and heat resistance, and that this modified polyphenylene ether is used as a matrix resin.

[0004] In addition, for the purpose of improving flatness and stabilizing signal transmission speed in glass cloth, it has been reported that a glass yarn having a yarn crimp density of 0.10 or less per cm with a crimp point having a curvature radius of 5 mm or less and a fold angle of 120 degrees or less is used (see, for example, Patent Document 3). Patent Document 3 states that by cylindrically grinding a silica glass ingot using a cylindrical grinding machine, a silica glass ingot having a desired roundness can be obtained, and by using such a silica glass ingot having a desired roundness, a glass filament which is a raw material for glass yarn can be obtained. It is described as follows.

[0005] In addition, an invention including the requirements of surface-treating a glass cloth with a silane coupling agent and adjusting the loss on ignition value of the glass cloth to 0.13 to 0.40 mass% has been reported (see, for example, Patent Document 4). Patent Document 4 states that for a glass cloth woven from glass yarns composed of glass filaments having a silicon dioxide (SiO 2 ) composition amount of 98 to 100 mass%, by adjusting the loss on ignition value of the glass cloth to the above range, it is possible to improve insulation reliability and suppress the generation of fluff on the glass cloth.

[0006] In addition, as an invention in the same technical field, the invention described in Patent Document 5 has been reported.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, the invention described in Patent Document 3 has a problem that the yield decreases because cylindrical grinding of the silica glass ingot is required. Therefore, there has been a strong demand for the provision of a technique for improving the flatness of a glass cloth without requiring special processing such as cylindrical grinding.

[0009] In addition, in an invention that includes as a requirement the surface treatment of a glass cloth with a silane coupling agent, there has been a problem that when the silane coupling agent remains unintentionally on the glass surface, the dielectric tangent of the glass cloth increases (see, for example, Patent Document 5 above). Therefore, there has been a strong demand for the creation of a technique for suppressing the fuzz of glass cloth by means other than means for adjusting the loss on ignition value.

[0010] An object of the present disclosure is to provide a glass cloth having excellent flatness and a reduced frequency of fuzz generation. Another object of the present disclosure is to provide a method for manufacturing a glass cloth, a glass yarn package, and a glass yarn that can provide such a glass cloth. Another object of the present disclosure is to provide a prepreg, a printed wiring board, an integrated circuit, and an electronic device using such a glass cloth. [Means for Solving the Problems]

[0011] Examples of embodiments of the present disclosure are as follows. [1] A glass cloth composed of glass yarns, wherein the silicon (Si) content in the glass yarn is 95.0 to 100% by mass in terms of silicon dioxide (SiO 2 ), and the snarl index of the glass yarn is 400 mm or less. [2] A glass cloth composed of glass yarns, wherein the bulk dielectric tangent of the glass constituting the glass yarn is in the range of 0.001 or less at 10 GHz, and the snarl index of the glass yarn is 400 mm or less. [3] The glass cloth according to item 1 or 2, wherein the snarl index of the glass yarn is 70 mm or more. [4] The glass yarn is in the ranges described in the following formulas (A), (B), and (C); (A) x + y + z = 100% by mass (B) x ≥ 99.5 mass% (C) 0.0003 ppm ≤ y ≤ 0.50 ppm x: Silicon content in terms of silicon dioxide (SiO 2 ) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium The glass cloth according to item 1 or 2, comprising glass fibers satisfying the following: [5] The glass cloth according to item 4, wherein the range of x is 99.6 mass% or more. [6] The glass cloth according to item 4, wherein the range of x is 99.9 mass% or more. [7] The glass cloth according to any one of items 1 to 6, wherein the glass fibers are treated with a surface treatment agent containing a silane coupling agent. [8] The surface treatment agent is represented by the following formula (1): X(R) 3-n SiY n ···(1) (In formula (1), X is an organic functional group having at least one of an amino group and an unsaturated double bond group having radical reactivity, Y is each independently an alkoxy group, n is an integer of 1 or more and 3 or less, and R is each independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group.) The glass cloth according to item 7, comprising the silane coupling agent represented by the above formula. [9] The glass cloth according to item 8, wherein X in the formula (1) is an organic functional group that does not form a salt with an ionic compound.

[10] The glass cloth according to item 8 or 9, wherein X in the formula (1) does not contain an amine and / or an ammonium cation.

[11] The glass cloth according to any one of items 8 to 10, wherein X in the formula (1) is an organic functional group having a methacryloxy group and / or an acryloxy group.

[12] The glass cloth according to any one of items 1 to 11, wherein the absolute value of the number of twists of the glass yarn is in the range of 0.5 to 1.5 turns / 25 mm.

[13] The glass cloth is formed by having the glass yarns as warp yarns and weft yarns. The glass cloth according to any one of items 1 to 12, wherein the absolute value of the difference in the number of twists between the warp yarns and the weft yarns is in the range of 0.01 to 0.70 turns / 25 mm.

[14] The glass cloth according to any one of items 1 to 13, wherein the thickness of the glass cloth is 60 μm or less.

[15] The glass cloth according to any one of items 1 to 14, which is for a printed wiring board.

[16] A prepreg containing the glass cloth according to any one of items 1 to 15 and a thermosetting resin.

[17] A printed wiring board including the prepreg according to item 16.

[18] An integrated circuit including the printed wiring board according to item 17.

[19] An electronic device including the printed wiring board according to item 17.

[20] A method for manufacturing a glass cloth, comprising: a step of obtaining a glass cloth using the glass yarn, wherein the silicon (Si) content in the glass yarn is in the range of 95.0 to 100% by mass in terms of silicon dioxide (SiO 2 ) conversion; and the snarl index of the glass yarn is 400 mm or less.

[21] A method for manufacturing a glass cloth, comprising: a step of obtaining a glass cloth using the glass yarn, wherein the bulk dielectric tangent of the glass constituting the glass yarn at 10 GHz is in the range of 0.001 or less; and the snarl index of the glass yarn is 400 mm or less.

[22] The method for manufacturing a glass cloth according to item 20 or 21, wherein the snarl index of the glass yarn is 70 mm or more.

[23] The glass yarn is within the ranges described in the following formulas (A), (B), and (C); (A) x + y + z = 100% by mass (B) x ≥ 99.5% by mass (C) 0.0003 ppm ≤ y ≤ 0.50 ppm x: Silicon content in terms of silicon dioxide (SiO 2 ) when converted y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium The method for manufacturing a glass cloth according to item 20 or 21, including the step of obtaining a glass cloth using the glass yarn that satisfies the above conditions.

[24] The step of warping the glass yarn used as the warp yarn (warp warping step), and The step of weaving using the glass yarn (weaving step), including In the warp warping step and / or the weaving step, the absolute value of the twist number of the glass yarn is adjusted to be in the range of 0.5 to 1.5 turns / 25 mm. The method for manufacturing a glass cloth according to any one of items 20 to 23.

[25] The glass cloth has the glass yarn as the warp yarn and the weft yarn, The method for manufacturing a glass cloth according to item 24, including the step of adjusting the twist number of the weft yarn so that the absolute value of the difference in the twist numbers of the warp yarn and the weft yarn is in the range of 0.01 to 0.70 turns / 25 mm.

[26] The method for manufacturing a glass cloth according to item 24 or 25, wherein the warp warping step and / or the weaving step are performed using the glass yarn whose value obtained by dividing the yarn width of the glass yarn by TEX is in the range of 10 to 30.

[27] A glass yarn package having a core material and a glass yarn wound around the core material, The silicon (Si) content in the glass fiber is 95.0 to 100% by mass in terms of silicon dioxide (SiO 2 ), and the snarl index of the glass fiber is 400 mm or less, a glass fiber package.

[28] The snarl index of the glass fiber is 70 mm or more, the glass fiber package according to item 27.

[29] The glass fiber is within the ranges described in the following formulas (A), (B), and (C); (A) x + y + z = 100% by mass (B) x ≥ 99.5% by mass (C) 0.0003 ppm ≤ y ≤ 0.50 ppm x: Silicon content when converted to silicon dioxide (SiO 2 ) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium The glass fiber package according to item 27 or 28, satisfying

[30] The absolute value of the twist number of the glass fiber is in the range of 0.5 to 1.5 turns / 25 mm, the glass fiber package according to any one of items 27 to 29.

[31] The value obtained by dividing the yarn width of the glass fiber by TEX is in the range of 10 to 30, the glass fiber package according to item 27 or 28.

[32] A glass fiber used for weaving a glass cloth, The silicon (Si) content in the glass fiber is 95.0 to 100% by mass in terms of silicon dioxide (SiO 2 ), and the snarl index of the glass fiber is 400 mm or less, a glass fiber.

[33] The snarl index of the glass fiber is 70 mm or more, the glass fiber according to item 32.

[34] The glass fiber is within the ranges described in the following formulas (A), (B), and (C); (A) x + y + z = 100% by mass (B) x ≥ 99.5 mass% (C) 0.0003 ppm ≤ y ≤ 0.50 ppm x: Silicon content in terms of silicon dioxide (SiO 2 ) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium The glass fiber according to item 32 or 33, satisfying the following:

[35] The glass fiber according to item 34, wherein y representing the total content of uranium and thorium is in the range of 0.0003 to 0.0010 ppm.

[36] The glass fiber according to item 34, wherein y representing the total content of uranium and thorium is in the range of more than 0.0010 ppm and not more than 0.0015 ppm.

[37] The glass fiber according to item 34, wherein y representing the total content of uranium and thorium is in the range of more than 0.0015 ppm and not more than 0.0018 ppm.

[38] The glass fiber according to item 34, wherein y representing the total content of uranium and thorium is in the range of more than 0.0018 ppm and not more than 0.0035 ppm.

[39] The glass fiber according to item 34, wherein y representing the total content of uranium and thorium is in the range of more than 0.0035 ppm and not more than 0.0040 ppm.

[40] The glass fiber according to item 34, wherein y representing the total content of uranium and thorium is in the range of more than 0.0040 ppm and not more than 0.09 ppm.

[41] The glass fiber according to item 34, wherein y representing the total content of uranium and thorium is in the range of more than 0.09 ppm and not more than 0.12 ppm.

[42] The glass fiber according to item 34, wherein y representing the total content of uranium and thorium is in the range of more than 0.12 ppm and not more than 0.50 ppm.

[43] The glass yarn according to any one of Items 32 to 42, wherein the snarl index of the glass yarn is in the range of 330 to 400 mm.

[44] The glass yarn according to any one of Items 32 to 42, wherein the snarl index of the glass yarn is in the range of 300 to 329 mm.

[45] The glass yarn according to any one of Items 32 to 42, wherein the snarl index of the glass yarn is in the range of 220 to 299 mm.

[46] The glass yarn according to any one of Items 32 to 42, wherein the snarl index of the glass yarn is in the range of 200 to 219 mm.

[47] The glass yarn according to any one of Items 32 to 42, wherein the snarl index of the glass yarn is in the range of 125 to 199 mm.

[48] The glass yarn according to any one of Items 32 to 42, wherein the snarl index of the glass yarn is in the range of 110 to 124 mm.

[49] The glass yarn according to any one of Items 32 to 42, wherein the snarl index of the glass yarn is 110 mm or less.

Advantages of the Invention

[0012] According to the present disclosure, it is possible to provide a glass cloth having excellent flatness and a reduced frequency of occurrence of fluff. Further, according to the present disclosure, it is possible to provide a method for manufacturing a glass cloth capable of providing such a glass cloth, a glass yarn package, and a glass yarn. Further, according to the present disclosure, it is possible to provide a prepreg, a printed wiring board, an integrated circuit, and an electronic device using such a glass cloth.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0014] Hereinafter, examples of embodiments of the present disclosure will be described. However, the present disclosure is not limited to the following embodiments, and thus various modifications are possible without departing from the gist thereof.

[0015] In this specification, when there are a plurality of structures represented by the same reference numeral in the same formula, unless otherwise specified, the structures may be independently selected and may be the same as or different from each other. Even when there are a plurality of structures represented by the same reference numeral in different formulas, unless otherwise specified, the structures may be independently selected and may be the same as or different from each other. Further, in this specification, the upper limit value or the lower limit value in the numerical range of the stepwise description may be replaced with the upper limit value or the lower limit value in the numerical range of the corresponding other stepwise description, and further may be replaced with the corresponding value described in the examples. Also, in this specification, the term "step" includes not only the case where it is an independent step but also the case where it cannot be clearly distinguished from other steps as long as the function of the step is achieved. In the content shown in the drawings, the scale, shape, and length may be exaggerated for further clarity.

[0016] 《Glass Cloth》 〈Overall Configuration〉 The glass cloth of the present disclosure is a glass cloth composed of glass yarns, wherein the silicon (Si) content in the glass yarns is 95.0 to 100% by mass in terms of silicon dioxide (SiO 2 ) and the snarl index of the glass yarns is in the range of 400 mm or less.

[0017] Further, the glass cloth of the present disclosure is a glass cloth composed of glass yarns, wherein the bulk dielectric tangent of the glass constituting the glass yarns at 10 GHz is in the range of 0.001 or less and the snarl index of the glass yarns is in the range of 400 mm or less.

[0018] The inventors of the present invention have found glass filaments that are advantageous for improving the dielectric properties of glass cloths, such as the following (1) and / or (2); (1) The glass filament in which the silicon (Si) content in the glass filament is 95.0 to 100% by mass in terms of silicon dioxide (SiO 2 2), (2) The glass filament in which the bulk dielectric tangent of the glass constituting the glass filament is in the range of 0.001 or less at 10 GHz, however, it has been found that residual stress is likely to occur in the glass cloth obtained by using this, and that such glass filaments tend to have a high snarl index. The inventors have further clarified that the flatness (waviness) of the glass cloth is more adversely affected by the glass cloth using glass filaments with a high snarl index.

[0019] Here, snarl refers to the twist generated in a twisted yarn in an attempt to unwind the twist, and in this specification, it means that the higher the snarl index, the easier it is for snarl to occur. In addition, in JIS-L-0210:1981, 3.1, item 1113, snarl is defined as "the entanglement (tangle) of the yarn formed by the twist when the twisted yarn is loosened." Conventionally, how the snarl index affects the quality of glass cloth has not been studied.

[0020] In addition, the inventors have found that for a glass filament (referred to as a "glass filament package" in the present disclosure) in a state where the glass filament is wound around a core material (in one aspect, a bobbin), the higher the snarl index of the glass filament, the easier it is for the glass filament to be unwound while rubbing against the surface of the bobbin when the glass filament is released from the bobbin. As a result, it has been clarified that fluff is likely to occur on the surface of the glass cloth obtained by using the glass filament. In particular, the inventors have also found that in the process of warping the glass filament used as the warp of the glass cloth (warp warping process), the unwinding speed of the glass filament is slower than in the process of weaving using the glass filament (weaving process), so the glass filament tends to rub against the surface of the bobbin.

[0021] Therefore, as a result of investigations from the perspective of reducing the snarling index, the present inventors have found that the snarling index can be adjusted according to the spinning conditions of glass filaments. In one preferred embodiment, glass filaments can be produced from a glass rod having a silicon content of 99.5 mass% or more. At this time, after heating and stretching the glass rod, annealing treatment can be performed to reduce (in one embodiment, eliminate) the residual stress generated in the glass filaments. According to the present disclosure, it is possible to provide a glass cloth that uses glass filaments with a controlled snarling index, can improve flatness, and can also reduce the occurrence frequency of fluff.

[0022] The basis weight (mass of the glass cloth) is preferably 8 to 250 g / m 2 and more preferably 8 to 100 g / m 2 and even more preferably 8 to 80 g / m 2 and particularly preferably 8 to 50 g / m 2 If the basis weight of the glass cloth is within the above range, the effects of the present disclosure can be easily obtained.

[0023] The thickness of the glass cloth is preferably 60 μm or less, more preferably 55 μm or less, and even more preferably 50 μm or less. If the thickness of the glass cloth is within the above range, the effects of the present disclosure can be easily obtained. The thickness of the glass cloth may be more than 0, 5 μm or more, or 5 μm or more.

[0024] 〈Glass Filament〉 The snarling index of the glass filament is in the range of 400 mm or less. When twist is applied to a filament, a untwisting torque that tries to return the twist is generated, and at this time, the filament may be twisted. Such twisting is referred to as "snarling" in this specification, and as an index of the ease of snarling generation, it is possible to use a snarling index as described in, for example, JIS L1095.

[0025] Glass yarns (glass filaments) such as E-glass yarns, which are suitable for use in printed wiring boards, are known to be obtained by extruding molten glass from a nozzle to obtain glass filaments with a diameter of several micrometers and then processing these filaments.

[0026] On the other hand, fused silica glass with a silicon (Si) content of 95.0 to 100% by mass in terms of silicon dioxide (SiO 2 ) has a melting point that is much higher than that of other glasses. Therefore, obtaining the glass filaments that are the raw material by heating and stretching a fused silica glass rod (fused silica glass ingot) is different from the above-mentioned E-glass yarns and the like. By heating and stretching a fused silica glass rod, the siloxane bonds that make up the glass are oriented in the stretching direction, and in this case, residual stress is likely to occur in the obtained glass filaments.

[0027] The inventors have found that "snarls", which were not recognized as a problem in conventional glass yarns, have an adverse effect on the hairiness quality and flatness of glass cloths due to this residual stress. Specifically, the higher the snarl index of the glass yarn, the easier it is for the glass yarn to come into contact with the bobbin surface when unwinding the glass yarn from the bobbin during warping of the warp yarns of the glass cloth, and as a result, hairiness is likely to occur on the surface of the glass cloth. Also, glass yarns with a high snarl index tend to have stronger undulations of the yarns even in the state of the glass cloth, and thus are likely to have an adverse effect on the flatness (warpage) of the glass cloth.

[0028] From the perspective of reducing the snarl index of fused silica glass yarns more than before for "snarls" that were not recognized as a problem in conventional glass yarns, a method of annealing the filaments or the glass yarn immediately after heating and stretching the glass filaments or the glass yarn is preferable. Such a method is relatively simple and is also advantageous in providing a glass cloth with excellent hairiness quality and flatness.

[0029] As a result of the inventors' investigations, it has been found that by setting the snarl index of the glass yarn to 400 mm or less, it is possible to perform warping of the warp yarns while reducing the frequency of hairiness on the surface of the glass cloth. From the viewpoint of easily obtaining the effects of the present disclosure, the snarl index of the glass yarn is preferably 70 to 400 mm. The upper limit value of the snarl index is preferably 380 mm or less, more preferably 370 mm or less, still more preferably 350 mm or less, even more preferably 330 mm or less, particularly preferably 310 mm or less, for example, 300 mm or less, 250 mm or less, 200 mm or less, 150 mm or less, or 100 mm or less, from the viewpoint of suppressing hairiness on the glass surface. The lower limit value of the snarl index that can be arbitrarily combined with these upper limit values may be 70 mm or more, 100 mm or more, 150 mm or more, 200 mm or more, 250 mm or more, 300 mm or more, or 330 or more. For example, from the viewpoint of easily obtaining the effects of the present disclosure, the snarl index of the glass yarn is preferably in the range of 330 to 400 mm, 300 to 329 mm, or 220 to 299 mm. From the viewpoint of slightly emphasizing the hairiness on the surface of the glass cloth in addition to the productivity of the glass yarn, the range of 200 to 219 mm is preferable. From the viewpoint of further emphasizing the hairiness on the surface of the glass cloth in addition to the productivity of the glass yarn, the range of 125 to 199 mm is preferable. From the viewpoint of even further emphasizing the hairiness on the surface of the glass cloth in addition to the productivity of the glass yarn, the range of 110 to 124 mm is even more preferable. From the viewpoint of particularly emphasizing the hairiness on the surface of the glass cloth in addition to the productivity of the glass yarn, the range of 110 mm or less, for example, 70 to 110 mm or less, is particularly preferable.

[0030] From the viewpoint of easily obtaining the effect of reducing the snarl index by annealing treatment, in the glass yarn, the silicon (Si) content is preferably 99.5 mass% or more in terms of silicon dioxide (SiO 2 ) conversion, more preferably in the range of 99.6 mass% or more, still more preferably in the range of 99.7 mass% or more, even more preferably in the range of 99.8 mass% or more, particularly preferably in the range of 99.9 mass% or more, 99.95 mass% or more.

[0031] A glass cloth is obtained by weaving glass yarns (for example, glass yarns composed of a plurality of glass filaments) as warp and weft. The weaving structure of the glass cloth includes, for example, weaving structures such as plain weave, matt weave, twill weave, and satin weave, and among them, a plain weave structure is preferable.

[0032] The driving-in density of the warp and the weft is preferably 10 to 120 threads / inch (= 10 to 120 threads / 25 mm), more preferably 40 to 100 threads / inch. If the driving-in density is within the above range, the effects of the present disclosure can be easily obtained. The driving-in densities of the warp and the weft may be different from each other.

[0033] The glass yarns constituting the glass cloth can be obtained by containing a so-called "low dielectric glass" as a raw material. The glass yarns (A), (B), and the range described in (C); (A) x + y + z = 100% by mass (B) x ≥ 99.5% by mass (C) 0.0003 ppm ≤ y ≤ 0.50 ppm x: Silicon content when converted to silicon dioxide (SiO 2 ) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium Preferably includes glass yarns that satisfy the above, and more preferably are glass yarns that satisfy the ranges described in (A), (B), and (C). By using glass yarns that satisfy the ranges described in (A), (B), and (C), for example, it is easy to improve the dielectric properties of the obtained glass cloth.

[0034] From the viewpoint of improving the dielectric properties of the obtained glass cloth, the range of x is preferably 99.6% by mass or more, more preferably 99.7% by mass or more, still more preferably 99.8% by mass or more, even more preferably 99.9% by mass or more, and particularly preferably 99.95% by mass or more.

[0035] The range of y is preferably the range described in the above (C), that is, 0.0003 ppm ≤ y ≤ 0.50 ppm. Since uranium (U) and thorium (Th) in the glass fiber can cause malfunction of the memory in electronic devices, the lower the total content thereof, the more preferable. As a result of investigations by the present inventors, although the mechanism of action is not necessarily clear, it has been found that the total content of uranium and thorium affects the control of the residual stress in the glass fiber and the adjustment of the snarling index. That is, the present inventors have found that, as a phenomenon peculiar to the case of producing glass fiber from a glass rod having a silicon content of 99.5% by mass or more, if the total content of uranium and thorium is 0.0003 ppm or more, it becomes easier to reduce the residual stress in the glass fiber. In this regard, the present inventors have also clarified that glass fibers with high residual stress have a strong untwisting force, so the snarling index of the glass fiber tends to be high, and glass cloths produced using such glass fibers are likely to warp and have poor flatness.

[0036] From the above viewpoints, conventionally, it has been a general technical recognition to make the total content of uranium (U) and thorium (Th) as low as possible. On the other hand, from the viewpoint of improving the flatness of the glass cloth, adjusting so that the total content of uranium and thorium is deliberately included within an appropriate range has not been done heretofore. As a result of intensive studies, the present inventors have found that the higher the total content of uranium and thorium in the glass fiber, the easier it is to exert the effect of the annealing treatment for reducing the snarling index in the glass fiber. From the viewpoint of easily obtaining the effects of the present disclosure described above, the range of y can be in the range of 0.0003 ppm ≤ y ≤ 0.50 ppm, and the lower limit value is preferably 0.001 ppm or more, more preferably 0.003 ppm or more, still more preferably 0.005 ppm or more, even more preferably 0.007 ppm or more, and particularly preferably 0.01 ppm or more. The upper limit value of y that can be arbitrarily combined with these lower limit values is preferably 0.45 ppm or less, more preferably 0.40 ppm or less, still more preferably 0.35 ppm or less, even more preferably 0.30 ppm or less, and particularly preferably 0.25 ppm or less. If the range of y is 0.0003 ppm or more, it is easy to avoid the situation where the residual stress generated during heat drawing becomes high because the purity of the silicon content in the glass is too high. As a result, it becomes easy to control the snarling index of the glass fiber within a range of 400 mm or less. On the other hand, if the range of y is 0.50 ppm or less, it is easy to avoid being affected by uranium and thorium. For example, in an electronic device including glass fiber in a component, malfunction of the memory becomes a problem in use. Also, from the viewpoint of easily improving the malfunction performance of the memory, y is preferably in the range of 0.0003 to 0.0010 ppm.In addition to the malfunction performance of the memory, from the viewpoint of easily reducing the snarl of the glass yarn, the range of y is more preferably more than 0.0010 and not more than 0.0015 ppm. From the viewpoint of more easily reducing the snarl of the glass yarn in addition to the malfunction performance of the memory, the range of y is more preferably more than 0.0015 and not more than 0.0018 ppm. From the viewpoint of more easily reducing the snarl of the glass yarn in addition to the malfunction performance of the memory, the range of y is even more preferably more than 0.0018 and not more than 0.0035 ppm. From the viewpoint of easily reducing the snarl of the glass yarn and facilitating the purification process of the quartz rod in addition to the malfunction performance of the memory, the range of y is more preferably more than 0.0035 and not more than 0.0040 ppm. From the viewpoint of more easily reducing the snarl of the glass yarn and even more facilitating the purification process of the quartz rod in addition to the malfunction performance of the memory, the range of y is particularly preferably more than 0.0040 and not more than 0.09 ppm.

[0037] 〈Bulk dielectric tangent〉 In this specification, the bulk dielectric tangent means the dielectric tangent measured at 10 GHz using a split cylinder resonator for the raw material of the glass cloth. The raw material of the glass cloth may be, for example, glass species, glass filaments, glass yarns, etc. The bulk dielectric tangent of the glass raw material constituting the glass cloth can be measured by the same method as the method for measuring the dielectric tangent of the glass cloth for a glass plate having a thickness of 300 μm or less and having the same type and composition as the glass raw material.

[0038] From the viewpoint of easily obtaining the effects of the present disclosure, the bulk dielectric tangent is preferably 0.0009 or less, more preferably 0.0008 or less, even more preferably 0.0007 or less, even more preferably 0.0005 or less, even more preferably 0.0004 or less, particularly preferably 0.0003 or less, and most preferably 0.0002 or less at 10 GHz. The bulk dielectric tangent may be more than 0.

[0039] 〈Average fibrillated degree of glass cloth〉 The average fiber opening degree of the glass cloth is preferably 38% or more, more preferably more than 40%, still more preferably more than 43%, still more preferably more than 46%, more than 50%, more than 53%, more than 56% or more than 60%, and particularly preferably more than 65%. If the average fiber opening degree of the glass cloth is 38% or more, when producing a prepreg or a printed wiring board containing the same, it is easy to suppress the remaining of bubbles called voids in the bundle of glass filaments, and thus it is difficult to have an adverse effect on solder heat resistance, insulation reliability, etc. Further, if the average fiber opening degree of the glass cloth is 38% or more, it is difficult to be affected by the snarl of the glass filaments, so even if glass filaments with a relatively high snarl index are used, it is easy to ensure the flatness of the glass cloth.

[0040] 〈Silane coupling agent〉 The glass filaments (including glass filaments) constituting the glass cloth are preferably surface-treated with a silane coupling agent. That is, in one aspect, the surface treatment agent for the glass filaments contains a silane coupling agent. Examples of the silane coupling agent include the following formula (1): X(R) 3-n SiY n ···(1) {In formula (1), X is an organic functional group having at least one of an amino group and an unsaturated double bond group having radical reactivity, Y is each independently an alkoxy group, n is an integer of 1 or more and 3 or less, and R is a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group} It is preferable to contain a silane coupling agent represented by the above formula.

[0041] Conventionally, the reasons for increasing the dielectric loss tangent of glass cloth are considered to be (i) thermally oxidized products of a very small amount of sizing agent remaining physically attached to the glass yarn surface, and (ii) residues of surface treatment agents or their modified products that physically adhere without forming a chemical bond with the glass surface and cannot be reduced by washing with water. From the perspective of suppressing the generation of the above (i) thermally oxidized products and / or (ii) residues or modified products, X in formula (1) is preferably an organic functional group that does not form a salt with an ionic compound. Further, from the perspective of reactivity with the matrix resin, X in formula (1) is more preferably an organic functional group having a methacryloxy group and / or an acryloxy group. From the perspective of easily obtaining the effects of the present disclosure, X in formula (1) preferably does not contain amines such as primary amines, secondary amines, and tertiary amines, and also preferably does not contain ammonium cations such as quaternary ammonium cations.

[0042] Regarding Y in the above formula (1), as the alkoxy group, from the perspective of stabilizing the treatment on the glass cloth, an alkoxy group having 1 to 5 carbon atoms (the carbon number is 1, 2, 3, 4, or 5) is preferable.

[0043] As the surface treatment agent, the silane coupling agent represented by formula (1) may be used alone, or may be used in a mixture of two or more silane coupling agents having different X in formula (1). Further, examples of the silane coupling agent represented by formula (1) include vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 5-hexenyltrimethoxysilane, etc., which can be used alone or as a mixture thereof.

[0044] The molecular weight of the silane coupling agent is preferably from 100 to 600, more preferably from 150 to 500, and still more preferably from 200 to 450. Among these, it is particularly preferable to use two or more types of silane coupling agents having different molecular weights. By treating the glass fiber with two or more types of silane coupling agents having different molecular weights, the density of the treatment agent on the glass surface becomes high, and thereby the reactivity with the matrix resin tends to be further improved.

[0045] From the viewpoint of being difficult to inhibit the reactivity with the resin, the silane coupling agent is preferably nonionic. Among nonionic silane coupling agents, a silane coupling agent having at least one group selected from the group consisting of a vinyl group, a methacryloxy group, and an acryloxy group is preferable, and among these, a silane coupling agent having a methacryloxy group and / or an acryloxy group is particularly preferable. By ensuring the reactivity with the resin, it is easy to enhance the heat resistance and reliability of the printed wiring board.

[0046] In one aspect, in formula (1), X is an organic functional group having at least one of the above unsaturated double bond group and amino group. Therefore, not only the aspect in which X has both the above unsaturated double bond group and the above amino group, but also the aspect in which X has the above unsaturated double bond group but does not have the above amino group and the aspect in which X does not have the above unsaturated double bond group but has the above amino group are both included in the scope of formula (1). However, X in formula (1) is preferably the above unsaturated double bond group and preferably does not contain an amino group.

[0047] 〈Loss on Ignition Value of Glass Cloth〉 From the perspective of reducing the dielectric loss tangent of the glass cloth, the ignition loss value of the glass cloth is preferably 0.010 mass% or more and less than 0.180 mass%, preferably 0.010 mass% or more and less than 0.174 mass%, more preferably 0.010 mass% or more and less than 0.150 mass%, and still more preferably 0.010 mass% or more and less than 0.130 mass%. If the ignition loss value is less than 0.180 mass%, it physically adheres without forming a chemical bond with the glass surface. For this reason, it is easy to avoid the situation where there are many residues of the surface treatment agent that cannot be reduced by water washing and / or its modified products on the glass cloth surface. As a result, it is easy to reduce the dielectric loss tangent of the glass cloth. If the ignition loss value is 0.010 mass% or more, it is easy to achieve sufficient adhesion between the matrix resin and the glass cloth. Therefore, when manufacturing a printed wiring board, it is easy to ensure its heat resistance and insulation reliability.

[0048] 〈Thread width / TEX value〉 The "thread width / TEX" value obtained by dividing the thread width of the glass yarn by its TEX is preferably in the range of 10 to 30. Such a value is preferably in the range of 11 to 29, more preferably in the range of 12 to 28, still more preferably in the range of 13 to 27, and particularly preferably in the range of 14 to 26. Here, the "thread width / TEX" value corresponds to a parameter representing the bundling property of the glass yarn. In the warping process of the warp yarns of the glass cloth, if the bundling property of the warp yarns is insufficient, the warp yarns are likely to have lint and thus yarn breakage is likely to occur. Therefore, if the "thread width / TEX" value is 30 or less, it is easy to ensure the bundling property of the glass yarn, and thus it is easy to prevent the cutting of the glass yarn in the warping process of the warp yarns. If the "thread width / TEX" value is 10 or more, it is easy to open the glass yarn in the next process, and thus it is easy to prevent poor impregnation of the matrix resin during prepreg production.

[0049] 〈Average filament diameter〉 The average filament diameter of the glass filaments constituting the glass yarn is preferably in the range of 2.5 to 10.0 μm, more preferably in the range of 2.5 to 9.0 μm, still more preferably in the range of 3.5 to 8.5 μm, even more preferably in the range of 3.5 to 8.0 μm, and particularly preferably in the range of 3.5 to 7.5 μm. If the filament diameter is 2.5 μm or more, it is easy to ensure the breaking strength of the filament, and therefore, it is easy to prevent the generation of flyers in the obtained glass cloth. If the filament diameter is 10.0 μm or less, it is easy to avoid an increase in the mass of the glass cloth, and therefore, it is easy to carry out transportation or processing.

[0050] 〈Twist number〉 The absolute value of the twist number of the glass yarn is preferably in the range of 0.5 to 1.5 turns / 25 mm. More preferably, it is in the range of 0.55 to 1.45 turns / 25 mm, still more preferably in the range of 0.57 to 1.4 turns / 25 mm, even more preferably in the range of 0.59 to 1.3 turns / 25 mm, and particularly preferably in the range of 0.60 to 1.2 turns / 25 mm. By adjusting the twist number of the glass yarn, it is possible to control the snarling index of the glass yarn. The larger the absolute value of the twist number, the stronger the untwisting force of the glass yarn tends to be, and therefore, the snarling index tends to be large. If the absolute value of the twist number of the glass yarn is 0.5 turns / 25 mm or more, it is easy to ensure the bundling property of the glass yarn, and therefore, it is easy to prevent the cutting of the glass yarn in the warp sizing process and the generation of flyers on the surface of the glass cloth. If the absolute value of the twist number of the glass yarn is 1.5 turns / 25 mm or less, it is easy to prevent the situation where the snarling index of the glass yarn becomes too large. In this case, it is easy to avoid the situation where flyers are likely to be generated on the surface of the glass cloth due to the rubbing of the glass yarn on the bobbin surface during the unwinding of the glass yarn.

[0051] It is preferable that the absolute value of the difference in the twist numbers of the warp and weft is in the range of 0.01 to 0.70 turns / 25 mm. If the absolute value difference is 0.01 turns / 25 mm or more, it is easy to enhance the flatness of the glass cloth, and it is also easy to fibrillate the glass yarn during the production of the glass cloth. If the absolute value difference exceeds 0.7 turns / 25 mm, since the directions of the untwisting forces of the warp and weft are different (for example, the warp is in the z direction and the weft is in the s direction), the glass cloth tends to warp greatly. Also, even when the untwisting force directions are the same, if the absolute value difference is large, the difference in the untwisting forces also tends to be large, so the warp of the glass cloth is likely to occur. Therefore, if the absolute value difference is 0.7 turns / 25 mm or less, it is easy to suppress the generation of flyers in the obtained glass cloth. It is more preferable that the absolute value of the difference in the twist numbers of the warp and weft of the glass cloth is in the range of 0.05 to 0.65 turns / 25 mm, and it is even more preferable that it is in the range of 0.07 to 0.55 turns / 25 mm. Also, it is more preferable that the absolute value of the difference in the twist numbers of the warp and weft of the glass cloth is in the range of 0.10 to 0.50 turns / 25 mm, and it is even more preferable that it is in the range of 0.15 to 0.45 turns / 25 mm.

[0052] The twist of the glass yarn is classified into the z direction or the s direction depending on the direction in which the twist is applied. In the present disclosure, the twist in the z direction is defined as "positive" and the twist in the s direction is defined as "negative". For example, in this specification, "a twist number of 1.00z" is expressed as having a twist number of 1.00, and "a twist number of 1.00s" is expressed as having a twist number of -1.00.

[0053] The twist number of the glass yarn can be adjusted, for example, in the process of twisting the glass yarn (twisting process). In one aspect, it is easy to increase the twist number of the glass yarn by converging the glass filaments. Increasing the twist number of the glass yarn easily suppresses the generation of flyers due to breakage of the glass filaments, and also easily suppresses thread breakage in the warping process of the glass cloth. On the other hand, due to the twist of the glass yarn, the width expansion of the glass yarn is likely to be inhibited, and uneven thickness of the glass cloth at the twisted part is likely to occur. Therefore, finding an appropriate twist number and using the glass yarn adjusted to such a twist number is advantageous in manufacturing a glass cloth with excellent quality.

[0054] "Glass Yarn Package" In a preferred embodiment, the present disclosure provides a glass yarn package in which glass yarns are wound around a core material. The glass yarn package has a silicon (Si) content in the glass yarn of 95.0 to 100 mass% in terms of silicon dioxide (SiO 2 2), and a snarling index of the glass yarn of 400 mm or less. By using such a glass yarn package, it is possible to provide a glass cloth that can improve flatness and reduce the occurrence frequency of fluff.

[0055] As a preferred requirement for the glass yarn constituting the glass yarn package, the preferred requirements for the glass yarn constituting the glass cloth may be referred to. For example, the glass yarn constituting the glass yarn package is within the ranges described in the following formulas (A), (B), and (C); (A) x + y + z = 100 mass% (B) x ≥ 99.5 mass% (C) 0.0003 ppm ≤ y ≤ 0.50 ppm x: Silicon content when converted to silicon dioxide (SiO 2 2) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium It is preferable to satisfy. Also, for the glass yarn constituting the glass yarn package, the absolute value of the twist number is preferably in the range of 0.5 to 1.5 turns / 25 mm, and the value of "yarn width / TEX" is preferably in the range of 10 to 30. Note that, similarly, for the preferred numerical ranges of the glass yarn constituting the glass yarn package, the preferred numerical ranges of the glass yarn constituting the glass cloth may be referred to.

[0056] The core material for winding the glass yarn may be any material that can suitably unwind the glass yarn from the core material. In one embodiment, it is a bobbin. However, the core material is not limited to a bobbin, and any material having a function or configuration equivalent to that of a bobbin may be used.

[0057] "Manufacturing Methods of Glass Yarn, Glass Yarn Package, and Glass Cloth" In preferred embodiments, the present disclosure provides manufacturing methods for glass yarn, glass yarn packages, and glass cloth. One aspect of such manufacturing methods is that the silicon (Si) content in the glass yarn is 95.0 to 100% by mass in terms of silicon dioxide (SiO 2 2), and the snarl index of the glass yarn is 400 mm or less, which is a manufacturing method of the glass yarn.

[0058] Also, one aspect of such manufacturing methods is a manufacturing method of a glass yarn package, which includes a step of winding the above glass yarn around a core material and forming a package.

[0059] Also, one aspect of such manufacturing methods is a manufacturing method of a glass cloth, which includes a step of obtaining a glass cloth using the glass yarn, where the silicon (Si) content in the glass yarn is in the range of 95.0 to 100% by mass in terms of silicon dioxide (SiO 2 2), and the snarl index of the glass yarn is in the range of 400 mm or less.

[0060] Also, one aspect of such manufacturing methods is a manufacturing method of a glass cloth, which includes a step of obtaining a glass cloth using the glass yarn, where the bulk dielectric tangent of the glass constituting the glass yarn at 10 GHz is in the range of 0.001 or less, and the snarl index of the glass yarn is in the range of 400 mm or less.

[0061] In the present disclosure, each of the above manufacturing methods can include a step of manufacturing glass filaments by heating and stretching a glass rod (manufacturing step of glass filaments) and a step of bundling a plurality of the glass filaments (bundling step of glass filaments).

[0062] 〈Manufacturing Step of Glass Rod〉 As a method for manufacturing a glass rod for manufacturing the glass cloth of the present disclosure, known techniques may be used. As the glass rod, fused silica glass produced by an electric melting method, a flame melting method, or the like may be used, or a synthetic quartz rod produced by a sol-gel method or the like may be used. In any manufacturing method, it is preferable to perform a purification treatment on the glass rod, which is the raw material, in order to adjust the silicon content in the glass fiber. Further, in order to easily control the snarl index of the glass fiber, it is preferable to perform a purification treatment on the glass rod so that the total content of uranium and thorium in the glass fiber is in the range of 0.0003 to 0.50 ppm. For example, in the case of fused silica glass, it is advantageous to use raw material powder with a low content of uranium and thorium. By using a glass rod having a total content of uranium and thorium within the above range, it is easy to reduce the drawing stress when processing the glass filament. As a result, it is easy to reduce the residual stress in the glass fiber, and thus it is easy to lower the snarl index of the glass fiber.

[0063] <Manufacturing Process of Glass Filament> In this step, a glass filament is manufactured by heating and drawing a glass rod. As a method for manufacturing and further processing a glass filament, known techniques may be used. For example, a method of heating and drawing a glass rod may be mentioned. In one aspect, a glass rod with a diameter of 1 to 50 mm can be heated and drawn in an electric furnace under an inert atmosphere at a temperature of 2000 °C, and a glass filament with a diameter of 3 to 10 μm can be manufactured. At this time, the diameter of the glass filament can be controlled by adjusting the speed ratio between the feeding speed of the glass rod into the electric furnace and the drawing speed of the glass filament. From the viewpoint of reducing the stress when drawing the glass rod, the temperature during heating and drawing is preferably in the range of 1700 to 2500 °C, more preferably in the range of 1800 to 2400 °C, and even more preferably in the range of 1900 to 2300 °C.

[0064] When heating and stretching a glass rod, the stress generated may remain in the resulting glass fiber. The inventors have found that the higher this residual stress, the greater the tendency for the snarl index of the glass fiber to increase. Further, the inventors have clarified that in order to adjust the snarl index of the glass fiber, it is effective to reduce the residual stress in the glass fiber after stretching, for example, by annealing treatment. By making the microcrystalline structure oriented by stretching into an unoriented state by annealing treatment, it is easy to reduce the snarl index of the glass fiber.

[0065] The annealing treatment is preferably performed between the step of heating and stretching the glass rod and the step of applying a sizing agent to the glass fiber. Further, from the viewpoint of easily reducing the residual stress of the glass fiber, the temperature during the annealing treatment is preferably in the range of 1000 to 1900 °C, more preferably in the range of 1100 to 1800 °C, still more preferably in the range of 1200 to 1700 °C, even more preferably in the range of 1300 to 1650 °C, and particularly preferably in the range of 1400 to 1600 °C. If the temperature during the annealing treatment is 1900 °C or lower, it tends to be easy to prevent the cutting of the glass filament after heat stretching. If the temperature during the annealing treatment is 1100 °C or higher, the effect of reducing the residual stress in the glass fiber is easily obtained. Also, the time during the annealing treatment is preferably in the range of 0.1 to 30 seconds, more preferably in the range of 0.2 to 20 seconds, still more preferably in the range of 0.3 to 5 seconds, and particularly preferably in the range of 0.4 to 3 seconds.

[0066] 〈Converging step of glass filament〉 In this step, a plurality of glass filaments are bundled. Generally, since a bundled glass filament is called a "strand", this step is also understood as a "method for producing a glass strand". As a method for producing a glass strand, known techniques may be used.

[0067] When producing glass strands, it is preferable to apply a sizing agent in order to enhance the convergence property of glass filaments with each other and also for the protection of the surface of the glass filaments. As a method of applying the sizing agent, for example, a method such as using a roller-type applicator is known.

[0068] As sizing agents, resin-based sizing agents such as PVA, polyurethane, and epoxy resin, and also starch-based sizing agents are known. From the viewpoint of the flying property of glass yarns in the weaving process and also from the viewpoint of the ease of removing the sizing agent from the glass yarns, a starch-based sizing agent is preferable as the sizing agent. Additives such as lubricants and antistatic agents may be added to the sizing agent in order to improve the functionality as glass yarns. From the viewpoint of easily suppressing the snarl of glass yarns, when converging glass filaments, it is preferable to adjust the shape of the yarn path and the heat drawing furnace so that as uniform a tension as possible is applied to each glass filament.

[0069] In order to adjust the "yarn width / TEX" value obtained by dividing the yarn width of the glass yarn by the TEX of the glass yarn to be in the range of 10 to 30, it is possible to adjust the adhesion amount of the sizing agent in the glass filament converging process. Here, from the viewpoint of easily obtaining the effects of the present disclosure, the loss on ignition value (LOI) of the glass yarn is preferably in the range of 1.0 to 2.5% by mass, more preferably in the range of 1.1 to 2.4% by mass, still more preferably in the range of 1.2 to 2.3% by mass, and particularly preferably in the range of 1.3 to 2.2% by mass. If the loss on ignition value of the glass yarn is 1.0% by mass or more, it is easy to ensure the convergence property of the glass filaments, and in this case, it is easy to adjust the "yarn width / TEX" value to be in the range of 10 to 30. If the loss on ignition value of the glass yarn is 2.5% by mass or less, it is easy to prevent oil removal failure and insufficient fibrillation in the oil removal process and the fibrillation process of the glass yarn.

[0070] 〈Twisting process〉 The method may include a step of applying a predetermined twist to the glass strands (twisting step). For the glass strands, a predetermined twist can be applied using, for example, a twisting machine. As the twisting machine or the twisting method, known devices or methods may be used. For example, a method of pulling out a roll of glass strands coated with a sizing agent (e.g., referred to as a "collet"), applying a twist, and winding it around a core material (in one aspect, a bobbin) can be mentioned. At this time, the bobbin is attached to the twisting machine using a fixing jig called a spindle. The twisting machine generally has a member called a traveler around the spindle, and the number of twists applied to the glass strands can be adjusted by the speed ratio of the operations of these various members.

[0071] The twisting step may also serve as a step of winding the twisted glass strands around the core material. Thereby, a glass yarn package can be produced.

[0072] 〈Method for manufacturing a glass cloth〉 The method for manufacturing a glass cloth includes a step of weaving the above glass yarns as warp and weft yarns to obtain a glass cloth (weaving step).

[0073] Further, the method for manufacturing a glass cloth may further include, before the above weaving step, aligning the warp yarns of the glass cloth using a glass yarn in which the value obtained by dividing the yarn width by the TEX of the glass yarn is in the range of 10 to 30, and then a warping step of applying a sizing agent; after the above warping step and before, during, or after the above weaving step, a step of heating and degreasing the glass yarn to remove the sizing agent adhering to the glass yarn (heating and degreasing step); a step of applying a surface treatment agent to the glass yarn (surface treatment step); and a step of splitting the glass yarn (splitting step). By having these steps, it is easy to provide a glass cloth excellent in flatness and hairiness quality.

[0074] The above glass processing method (heating and degreasing process, surface treatment process, and fiber opening process) can be applied to glass yarns before weaving, and can also be applied to woven glass cloth. In other words, the process of weaving glass yarns to obtain glass cloth may be provided before, during, or after the glass processing method. Note that in the glass processing method, "reduction" means, for example, removing at least a part of the sizing agent or silane coupling agent, and there may be residues that could not be completely removed. Hereinafter, an embodiment including a warping process, a weaving process, a heating and degreasing process, a surface treatment process, and a fiber opening process in this order will be described as an example. However, the present disclosure is not limited to only the following examples.

[0075] 〈Warping process〉 In the warping process, glass yarns with an Si content in the range of 95.0 to 100% by mass in terms of SiO 2 conversion can be used. After aligning the warp yarns, a sizing agent (sizing agent) can be applied to the glass yarns. By providing a sizing agent to the glass yarns, it is easy to suppress the generation of flyers in the glass cloth. As the sizing agent, it is preferable to use those with relatively high sizing properties, such as starch and PVA. In order to uniformly apply the sizing agent to the glass yarns, it is preferable to immerse the glass yarns in the sizing agent, then remove the excess sizing agent with a squeeze roller, and then dry the sizing agent.

[0076] 〈Weaving process〉 In the weaving process, the weft yarns can be woven into the warp yarns prepared in the warping process using a loom. Known looms include air jet type, rapier type, shuttle type, etc. From the viewpoint of suppressing the flyers of the glass cloth, it is preferable to use an air jet type loom. The absolute value of the twist number of the above glass yarns in the warp warping and weaving processes is preferably in the range of 0.5 to 1.5 turns / 25 mm. Also, in this process, it is preferable to adjust the twist number of the weft yarn so that the absolute value of the twist number difference between the warp yarn and the weft yarn is in the range of 0.01 to 0.70 turns / 25 mm.

[0077] <Heating and degreasing process> In the heating and degreasing process of the glass cloth, by heating the glass yarns, it is possible to reduce the sizing agent (sizing agent) and its residues, as well as their modified products, etc. that are arbitrarily attached to the glass yarns, and preferably, it is possible to remove them. By performing the heating and degreasing process, it becomes possible to form a surface treatment layer on the surface of the glass yarn (glass filament) after reducing the organic substances that can increase the dielectric loss tangent, so it is easy to produce a glass cloth with excellent dielectric properties. As a means for heating and degreasing, known means (heating means, heating medium, heating mechanism, heating device, heating parts, etc.) can be used.

[0078] As one aspect of the heating and degreasing process, for example, a method of heating the glass cloth at a temperature of 600 to 1600 °C is known.

[0079] In the heat treatment process, by heating the green glass cloth with a softening point of the glass yarn of 900 °C or higher in the temperature range of 600 to 1600 °C, it is easy to suppress damage to the glass cloth and easy to reduce the dielectric loss tangent of the glass cloth. From the viewpoint of preferably obtaining the effects of the present disclosure, the heating and degreasing temperature is preferably 700 to 1500 °C, more preferably 800 to 1400 °C, still more preferably 900 to 1300 °C, and particularly preferably 1000 to 1200 °C. When the heating and degreasing temperature is 600 °C or higher, it is easy to effectively remove the sizing agent and the like attached to the cloth, so it is easy to produce a glass cloth with excellent dielectric properties. When the heating and degreasing temperature is 1600 °C or lower, it is easy to suppress the devitrification phenomenon of the glass, and as a result, it is easy to prevent the strength of the glass cloth from decreasing.

[0080] The heating time is preferably 30 minutes or less, more preferably 15 minutes or less, still more preferably 5 minutes or less, and particularly preferably 90 seconds or less. Since the heat treatment is performed at a high temperature, when the heating time is 30 minutes or less, the damage to the glass cloth is likely to be small. In this case, for example, it is easy to avoid problems such as holes partially opening in the glass cloth during processing and the glass cloth being cut. 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 the sizing agent and the like.

[0081] When performing the heat degreasing of the glass cloth in a closed system, from the viewpoint of suitable heating by the heating means, it is preferable to place the glass cloth in a heating furnace. Further, from the viewpoints of storage space and efficiency of the heating range, it is preferable to heat the glass cloth while storing it in a rolled state. Furthermore, from the viewpoints of increasing the removal efficiency of organic substances and shortening the removal time of organic substances, it is preferable to heat the glass cloth while conveying it in the heating furnace. The conveyance of the glass cloth can be performed, for example, by a combination of an unwinding mechanism and a winding mechanism.

[0082] When performing the heat degreasing of the glass cloth in an open system, from the viewpoint of ensuring the heated area, it is preferable to heat the glass cloth while conveying it. The conveyance of the glass cloth can be performed, for example, by a combination of an unwinding mechanism and a winding mechanism.

[0083] The mode of the heat degreasing process is not limited to the above. As a further mode of the heat degreasing process, for example, a method of heating under conditions where the heating amount represented by the heating temperature (°C) × heating time (h) of 100°C or higher is 450 (°C·h) or more in a vacuum or a gas with a dew point of 15°C or lower (however, the maximum heating temperature is 100 to 600°C), etc. are also known.

[0084] 〈Heating means〉 As the heating means, for example, a heating furnace, an electric heater, a burner, etc. can be considered. Among them, a gas single radiant tube burner or an electric heater is preferable. A plurality of different heating means may be combined.

[0085] From the viewpoint of efficiently removing the organic substances adhering to the surface of the glass cloth, a continuous method of continuously heating the glass cloth while passing it through a heating furnace is preferable to a batch method of heating the glass cloth wound around a core at a predetermined ambient temperature. A method that can continuously wash the glass cloth using washing water with a low metal ion content, such as reverse osmosis (RO) water or ion-exchanged water, is more preferable.

[0086] Further, from the perspective of low running costs, as a heating means, the glass cloth may be heated by bringing a member (contact member) heated to a predetermined temperature into contact with the glass cloth.

[0087] The contact member is preferably one that can heat the glass cloth at a high temperature. From the perspective of ease of transporting the glass cloth, the shape of the contact member is preferably a roll shape. Specifically, as the contact member, for example, a roll heated by an induction heating method that can be used in a high-temperature region and has relatively little variation in temperature in the width direction is preferable. When heating the glass cloth with the contact member, it is considered that the temperature of the contact member and the surface temperature of the glass cloth are generally equal.

[0088] When continuously heating the glass cloth, in order to remove carbides adhering to the roll, the method using the above roll preferably has a mechanism for removing adhered foreign substances, for example, a mechanism such as a blade.

[0089] 〈Steam application means〉 The means (steam application means) for applying the above to the glass cloth may be spraying, shower diffusion, jet nozzles, etc. Alternatively, the gas discharged from the heating furnace can be reused as high-temperature steam.

[0090] The steam applied to the glass cloth may contain, for example, a volatile solvent, water vapor, a gas other than water vapor, but water vapor is preferable from the perspective of suppressing toxicity to the human body and from the perspective of easily promoting the decomposition of the sizing agent used for glass fibers. The temperature of the high-temperature steam may be a temperature at which the surface temperature of the glass cloth is higher than 650°C. In this case, if necessary, a method of supplying high-temperature steam and heated air at an arbitrary ratio may be adopted. The temperature of the high-temperature steam may be 400°C or higher, 450°C or higher, 550°C or higher, 600°C or higher, or 650°C or higher.

[0091] 〈Surface treatment process〉 The surface treatment process can be applied to glass fibers and can also be applied to glass cloth. In other words, the process of weaving glass fibers to obtain glass cloth may be provided before, during, or after the glass treatment method according to the present disclosure.

[0092] The step of attaching the surface treatment agent can include, for example, at least one of a coating step of attaching a silane coupling agent to the surface of the glass with a treatment liquid having a concentration of 0.1 to 0.5% by mass, and a fixing step of fixing the silane coupling agent to the surface of the glass by heat drying. This makes it easier to preferably surface-treat the glass.

[0093] As a method of applying the treatment liquid to the glass in the coating step, (a) a method of immersing or passing the glass through the treatment liquid stored in a bath (hereinafter referred to as the "immersion method"), (b) a method of applying the treatment liquid to the glass with a roll coater, die coater, gravure coater, etc. are possible. When adopting the immersion method, it is preferable to select the immersion time of the glass in the treatment liquid to be 0.5 seconds or more and 1 minute or less. Also, when adopting the immersion method, the glass can be passed through the treatment liquid at a conveyance speed of 10 to 50 m / min while applying a predetermined tension (for example, 100 to 250 N) to the glass. Further, after applying the treatment liquid to the glass, the solvent contained in the treatment liquid can be heated and dried by methods such as hot air and electromagnetic waves.

[0094] The concentration of the treatment liquid is preferably 0.1 to 0.5% by mass, more preferably 0.1 to 0.45% by mass, and still more preferably 0.1 to 0.4% by mass. According to this, it becomes easier to preferably surface-treat the glass.

[0095] In the fixing step, the heat drying temperature is preferably 80°C or higher, more preferably 90°C or higher, so that the reaction between the silane coupling agent and the glass is sufficiently carried out. Also, the heat drying temperature is preferably 300°C or lower, more preferably 180°C or lower, in order to prevent deterioration of the organic functional groups of the silane coupling agent.

[0096] The step of reducing the silane coupling agent can include, for example, a cleaning step of cleaning the silane coupling agent that did not form a chemical bond with the surface of the glass, a drying step of heating and drying the glass after cleaning, and a finishing cleaning step of reducing unnecessary components that were not completely cleaned and did not form a chemical bond with the surface of the glass. By doing so, it becomes easier to control the loss on ignition value. Note that the step of reducing the silane coupling agent can include, for example, a finishing drying step after the finishing cleaning step.

[0097] Among these, in the finishing cleaning step, it is possible to reduce unnecessary components that were not completely cleaned with water in the cleaning step and did not form a chemical bond with the surface of the glass. In this finishing cleaning step, for example, an organic solvent can be used as the cleaning liquid. By having the finishing cleaning step, even when using a low dielectric glass as described in the present disclosure, it becomes easier to adjust the difference between the dielectric tangent of the obtained glass cloth and the bulk dielectric tangent within the numerical range described above. As the organic solvent here, an organic solvent with high hydrophobicity is preferable, and an organic solvent with high affinity for the residue and modified product of the silane coupling agent having a hydroxyl group is also preferable. As the cleaning method, a dipping method, a shower spray, etc. can be adopted, and it may be heated or cooled as necessary. It is preferable to reduce the excess solvent from the cleaned glass by means of a squeezing roller or the like so as to suppress redeposition of the glass dissolved in the cleaning liquid.

[0098] As the organic solvent that can be used as the cleaning liquid in the finishing cleaning process, for example, the following solvents can be used alone or in combination of multiple types. Examples of highly hydrophobic organic solvents include saturated chain aliphatic hydrocarbons such as n-pentane, i-pentane, n-hexane, i-hexane, n-heptane, i-heptane, n-octane, i-octane, 2,2,4-trimethylpentane (isooctane), n-nonane, i-nonane, n-decane, i-decane, 2,2,4,6,6-pentamethylheptane (isododecane); saturated cyclic aliphatic hydrocarbons such as cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, ethylcyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, trimethylbenzene, triethylbenzene; halogen-containing solvents such as chloroform, dichloromethane, dichloroethane; etc. Examples of organic solvents with high affinity for residues or modified products of silane coupling agents include alcohols such as methanol, ethanol, butanol; ketones such as acetone, methyl ethyl ketone; ethers such as methyl ethyl ether, diethyl ether; amides such as N,N-dimethylformamide, N,N-dimethylacetamide; dimethyl sulfoxide; etc. Among them, from the viewpoint of being easily able to efficiently reduce the silane coupling agent physically adhered to glass, aromatic hydrocarbons, alcohols or ketones are preferred, and methanol is more preferred. Therefore, as the cleaning liquid in the finishing cleaning process, it is preferable to use a cleaning liquid with methanol as the main component (methanol is 50% by mass or more, or 60% by mass or more based on 100% by mass of the cleaning liquid).

[0099] In the finishing drying process, the cleaning liquid used in the above-mentioned finishing cleaning process can be reduced. From the ease of reducing the cleaning liquid by drying, the cleaning liquid used in the above-mentioned finishing cleaning process preferably has a boiling point of 120°C or lower. For drying, a method of heat drying or blowing drying can be adopted. When an organic solvent is used as the cleaning liquid, from the viewpoint of safety, it is preferable to perform heat drying by hot air drying using low-pressure steam or heat transfer oil as a heat source. The drying temperature is preferably equal to or higher than the boiling point of the cleaning liquid, and preferably 180°C or lower from the viewpoint of suppressing the deterioration of the silane coupling agent.

[0100] 〈Fibrillation process〉 As a fibrillation method in the fibrillation process, for example, a method of fibrillating a glass cloth with spray water (high-pressure water fibrillation), a vibro washer, ultrasonic water, a mangle, or the like can be adopted. During this fibrillation process, by reducing the tension applied to the glass cloth, the air permeability tends to be made smaller. In addition, in order to suppress a decrease in the tensile strength of the glass cloth due to the fibrillation process, it is preferable to take measures such as reducing the friction with the contact member when weaving the glass yarn, optimizing the sizing agent, and increasing the adhesion. As a fibrillation method for a glass cloth composed of glass yarns with high glass hardness, dry ice blasting is preferable.

[0101] The above processes do not necessarily have to be performed in separate processes, and a plurality of processes can also be combined into one process. For example, when the cleaning process is performed after the weaving process, by using high-pressure water spray or the like in the cleaning process, the fibrillation process can be combined. In many cases, the composition of the glass cloth usually does not change before and after fibrillation. In addition, the manufacturing method of the glass cloth can have arbitrary processes other than the above processes. For example, after the fibrillation process, a slitting process can be included. Also, if possible, the order of the above processes can be changed.

[0102] 〈Prepreg〉 The prepreg according to the present disclosure contains the above-mentioned glass cloth and a matrix resin impregnated in the glass cloth. Thereby, a prepreg with few voids can be provided.

[0103] As the matrix resin, a thermosetting resin or a thermoplastic resin can be used. If possible, both may be used in combination, or other resins may be further included.

[0104] Examples of the thermosetting resin include (a) An epoxy resin obtained by reacting a compound having an epoxy group with a compound having at least one group selected from the group consisting of an amino group, a phenol group, an acid anhydride group, a hydrazide group, an isocyanate group, a cyanate group, and a hydroxyl group that reacts with the epoxy group and curing; (b) A radical polymerization type cured resin obtained by curing a compound having at least one group selected from the group consisting of an allyl group, a methacryl group, and an acryl group; (c) A maleimide triazine resin obtained by reacting a compound having a cyanate group with a compound having a maleimide group and curing; (d) A thermosetting polyimide resin obtained by reacting a maleimide compound with an amine compound and curing; (e) A benzoxazine resin obtained by crosslinking and curing a compound having a benzoxazine ring by heat polymerization. And the like are exemplified. In addition, in obtaining the (a) epoxy resin, the compounds can be reacted without a catalyst, or a catalyst having a reaction catalytic ability such as an imidazole compound, a tertiary amine compound, a urea compound, and a phosphorus compound can be added to react the compounds. Further, in obtaining the (b) radical polymerization type cured resin, a thermal decomposition type catalyst or a photo decomposition type catalyst can be used as a reaction initiator.

[0105] Examples of the thermoplastic resin include polyphenylene ether, modified polyphenylene ether, polyphenylene sulfide, polysulfone, polyethersulfone, polyarylate, aromatic polyamide, polyetheretherketone, thermoplastic polyimide, insoluble polyimide, polyamideimide, and fluororesin. As the insulating material of the printed wiring board for high-speed communication, polyphenylene ether or modified polyphenylene ether rich in radical reactivity is preferable.

[0106] When the matrix resin used in the printed wiring board for high-speed communication has a vinyl group or a methacryl group, it has relatively high hydrophobicity, and a silane coupling agent having a functional group involved in the radical reaction such as a methacryl group has good compatibility with the matrix resin.

[0107] As described above, the thermosetting resin and the thermoplastic resin can be used in combination. Further, the prepreg can further contain an inorganic filler. The inorganic filler is preferably used in combination with the thermosetting resin. Examples thereof include aluminum hydroxide, zirconium oxide, calcium carbonate, alumina, mica, aluminum carbonate, magnesium silicate, aluminum silicate, silica, talc, short glass fiber, aluminum borate, and silicon carbide. The inorganic filler may be used alone or in combination of two or more.

[0108] 〈Printed Wiring Board〉 The printed wiring board according to the present disclosure contains the above prepreg. Thereby, a printed wiring board excellent in insulation reliability can be provided.

[0109] 〈Integrated Circuit and Electronic Device〉 In addition, an integrated circuit and an electronic device including the above printed wiring board are also an aspect of the present disclosure. The integrated circuit and the electronic device obtained by using the printed wiring board according to the present disclosure are excellent in various characteristics.

Examples

[0110] Examples of embodiments of the present disclosure will be described below with reference to Examples and Comparative Examples. However, the present disclosure is not limited to only the following Examples. For the Examples and Comparative Examples, various manufacturing, measurement, and evaluation operations were performed by the following methods. Unless otherwise specified, various manufacturing, measurement, and evaluation operations were performed at room temperature (25°C) and under atmospheric pressure.

[0111] 《Measurement》 〈Thickness of glass cloth (μm)〉 In accordance with 7.10 of JIS R 3420, the thickness of the glass cloth was determined. Specifically, using a micrometer, the spindle was gently rotated and lightly contacted parallel to the measurement surface of the sample. Then, the scale reading after the ratchet made three clicks was read. Note that 7.10 of JIS R 3420 stipulates general test methods for cross products such as glass cloth. is described.

[0112] 〈Snarling index of glass yarn (mm)〉 In accordance with 9.17 of JIS L 1095, the snarling index of the glass yarn was determined. Specifically, first, with the initial load described in Method A described in 9.17.1 of JIS L 1095 applied to the glass yarn (sample), the glass yarn was stretched so as to be straight with respect to the gripping interval, and a load of 1.1×10 ―6 N / tex was placed on the central part thereof. At a speed of 0.5 m / min, one gripper B was brought closer to the other gripper A to slacken the above sample. The number on the scale plate at the position of gripper B when snarling occurred at the load point at that time was read. The number of test times was 30, and the snarling index was determined by obtaining the average value.

[0113] 〈TEX of glass yarn (g / 1000m)〉 Based on JIS R3420:2012, the TEX of the glass fiber was determined. Specifically, the glass fiber sampled to be 1000 m was subjected to a heat degreasing treatment in a muffle furnace set at 625 ± 20 °C for 30 minutes, thereby removing the sizing agent adhering to the glass fiber. At this time, whether the sizing agent was removed was judged by whether the weight loss of the glass fiber was less than 0.1 mass% before and after the heat degreasing. That is, it was judged that the sizing agent was removed when the weight loss of the glass fiber was less than 0.1 mass% before and after the heat degreasing. The TEX of the glass fiber was determined by measuring the weight of 1000 m of the glass fiber after the heat degreasing treatment was completed.

[0114] 〈Content of each element contained in the glass fiber〉 The contents of silicon, uranium, and thorium constituting the glass fiber were determined by the absolute calibration curve method using an ICP mass spectrometer.

[0115] 〈Content of silicon (mass%)〉 In order to reduce the impurities (such as sizing agents, etc.) adhering to the glass fiber or its raw materials, the calibration solution was adjusted by the following method. That is, the glass fiber (sample) was weighed, hydrolyzed with sodium hydroxide, and then dissolved with dilute nitric acid to adjust the calibration solution.

[0116] For the obtained calibration solution, the content of silicon was measured using an ICP emission spectrometer (PS3520VDDII manufactured by Hitachi High-Tech Science Corporation), and then the content of silicon contained in the sample was determined by converting it to an oxide value.

[0117] 〈Contents of uranium and thorium (ppm)〉 The weighed glass fiber (sample) was heated and washed with aqua regia, and then washed with ultrapure water. This sample was decomposed with nitric acid, hydrofluoric acid, and sulfuric acid, heated and concentrated until white smoke of sulfuric acid was generated, and then the calibration solution was adjusted using dilute nitric acid.

[0118] For the obtained constant-volume solution, uranium and thorium were measured using an ICP mass spectrometer (SPQ9400 manufactured by SII NanoTechnology Inc.), and the contents of uranium and thorium contained in the sample were determined respectively.

[0119] 〈Content of other components (mass %)〉 By subtracting the values of the contents of the above-mentioned silicon, uranium, and thorium from 100 mass %, the contents of other components (elements other than silicon, uranium, and thorium) in the glass fiber (sample) were determined. Other components are represented as "impurities" in the following table. Here, regarding the unit "ppm" indicating the contents of uranium and thorium, it was converted as 1 ppm = 0.0001 mass %.

[0120] 〈Twist number of glass fiber and its absolute value difference (turns / 25 mm)〉 Measurement was carried out according to JIS R3420, and the twist number (turns / 25 mm) of the glass fiber was obtained. When measuring the twist number, in order to accurately measure the twist number of the glass fiber in the glass cloth, the glass fiber (warp or weft) was pulled out from the glass cloth, and the measurement was carried out for the glass fiber (the warp or the weft). Regarding the obtained value, the twist in the z direction was regarded as positive and the twist in the s direction was regarded as negative. For example, a twist of 1.00z (a twist of 1.00 (turns / 25 mm) in the z direction) was treated as +1.00, and a twist of 1.00s (a twist of 1.00 (turns / 25 mm) in the s direction) was treated as -1.00. And by the following formula: Absolute value difference of twist number = |Twist number of warp - Twist number of weft| the absolute value difference (turns / 25 mm) of the twist numbers of the warp and the weft was calculated.

[0121] 〈Yarn width of glass fiber (μm)〉 While transporting the glass fiber at a speed of 1 m / min, a transmission type dimensional measuring instrument using the LED projection method (HIGH ACCURACY CMOS MICROMETER LS-9006MR, manufactured by KEYENCE CORPORATION) was used, and the bundle width of the glass fiber was measured over a length of 50 m. From the obtained bundle width data for 50 m in length, the ratio occupied by a specific bundle width or less and the average value of the bundle width were calculated. The measurement of the bundle width by the transmission type dimensional measuring instrument using the LED projection method was performed under the condition that 1934 measurement values are obtained per meter. When an error occurred due to, for example, the LED being out of focus (-9999 value is displayed), the measurement value was deleted and the average value of the glass fiber width was calculated. In addition, measurement values where an error occurred were appropriately omitted for the calculation. The tension acting on the glass fiber when the glass fiber was transported was 0.12 to 0.18 N when measured with a tensiometer (Conrol instruments ETPB-100-C0585, manufactured by SCHMIDT).

[0122] 〈Yarn width / TEX (μm / (g / 1000m))〉 The value of yarn width / TEX was obtained by dividing the yarn width obtained above by the TEX obtained above.

[0123] 〈Bulk dielectric tangent at 10 GHz〉 In accordance with IEC 62562, the bulk dielectric tangent at 10 GHz of each glass rod (bulk), which is the raw material of each glass fiber, was determined. Specifically, a glass plate sample of 300 μm or less sampled to a size required for measurement with a split cylinder resonator was stored in a thermo-hygrostat oven at 23°C and 50% RH for 8 hours. Then, the dielectric properties of the stored sample were measured using a split cylinder resonator (manufactured by EM LABO) and an impedance analyzer (manufactured by Agilent Technologies). The measurement was performed 5 times for each sample, and the average value was determined. Note that IEC 62562 mainly stipulates the measurement method of the dielectric properties of fine ceramics materials used in microwave circuits in the microwave band.

[0124] 〈Number of Filaments and Filament Diameter (μm) of Warp and Weft〉 In calculating the average fibrillation degree, the number of filaments and the filament diameter of the warp and weft were determined by observing cross-sectional images of the glass yarns. Specifically, a cross-sectional image of the glass yarn as the warp (or weft) was obtained, and the number of filaments and the filament diameter of the warp (or weft) were measured in the cross-sectional image. Similarly, the image acquisition of the glass yarn and the measurement of the number of filaments were repeated, and the average value of the five obtained measurement values was treated as the number of filaments and the filament diameter of the warp (or weft).

[0125] 〈Warp Width and Weft Width〉 In calculating the average fibrillation degree, the warp width and the weft width were determined by the following method. First, five samples of glass cloth with a size of 70 mm in the warp direction and 70 mm in the weft direction were cut out from the glass cloth. The cut samples were each observed vertically from above at a magnification of 100 using a macroscope. For each sample, the yarn widths of 250 warps (or wefts) were randomly measured, and the average value of the yarn widths of the 250 obtained warps (or wefts) was determined. The determined average value was treated as the warp width (or weft width).

[0126] 〈Fibrillation Degree (%) of Warp and Weft, and Average Fibrillation Degree (%) of Glass Cloth〉 The fibrillation degree of the warp of the glass cloth was calculated by the following formula: Fibrillation degree of warp (%) = [Warp width (μm) / {Number of warp filaments × Warp filament diameter (μm)}] × 100 And was calculated by the formula. Also, the fibrillation degree of the weft of the glass cloth was calculated by the following formula: Fibrillation degree of weft (%) = [Weft width (μm) / {Number of weft filaments × Weft filament diameter (μm)}] × 100 And was calculated by the formula.

[0127] Using the calculated fibrillation degree (%) of the warp and the fibrillation degree (%) of the weft, the following formula: Average fibrillation degree (%) = {Fibrillation degree of warp (%) + Fibrillation degree of weft (%)} / 2 Based on this, the average fiber opening degree was calculated.

[0128] 〈Linting Quality〉 The glass cloths obtained in the examples and comparative examples were visually inspected while applying a tension of 100 N / 1000 mm and irradiating with a halogen lamp using a Roll-to-Roll inspection table to determine the number of lintings, particularly the number of lintings with protrusions of 1 mm or more. The number of lintings per 1 m 2 was treated as the frequency of lintings, and the linting quality was evaluated according to the following criteria using this. (Measurement Criteria) Linting Quality A: The frequency of lintings is 10 per m 2 or less. Linting Quality B: The frequency of lintings is 11 - 20 per m 2 . Linting Quality C: The frequency of lintings is 21 per m 2 or more.

[0129] 〈Amount of Warping of Glass Cloth〉 Samples were obtained by cutting the glass cloths obtained in the examples and comparative examples into dimensions of 200 mm × 200 mm. This sample was placed on a measurement table with a flat surface, and the amount of warping in the glass cloth was measured.

[0130] Figures 1(a) - (b) are schematic diagrams for explaining the method of measuring the amount of warping in the glass cloth. Among these, Figure 1(a) is a plan view of the glass cloth and the placement table seen from above, and Figure 1(b) is a cross-sectional view of the left end portion of the glass cloth in Figure 1(a) (the portion surrounded by the dotted line A) when seen with the left end being in the front - back direction, respectively, schematically shown. In Figures 1(a) - (b), the x-direction, y-direction, and z-direction respectively correspond.

[0131] As shown in the figure, the sample 2 of the glass cloth is placed on the measurement table 1 with a flat surface. The sample 2 is curved so as to rise from the measurement table 1 at the left end, and thus floats by a height T1. At this time, the height T1 is treated as the amount of warping at the left end portion in the glass cloth. And, similar to the examples shown in FIGS. 1(a) to (b), the height T2 at the upper end portion of the glass cloth, the height T3 at the right end portion of the glass cloth, and the height T4 at the lower end portion of the glass cloth, are each treated as the amount of warping at the upper, right, and lower end portions of the glass cloth. Among the amounts of warping at the four ends of the glass cloth, the maximum amount of warping Tmax is represented as the "amount of warping" in the following table.

[0132] FIGS. 2(a) to (b) are schematic diagrams for further explaining the method of measuring the amount of warping. FIGS. 2(a) to (b) correspond to the cross section of the portion surrounded by the dotted line A in FIG. 1(a). Among these, in FIG. 2(a), the sample is curled at the left end. In this case, the height Ta at the apex portion of the curl is treated as the amount of warping at the left end portion of the glass cloth. Also, in FIG. 2(b), the sample is curved in a peak shape at the left end. Even in this case, the height Tb at the peak portion of the peak shape is treated as the amount of warping at the left end portion of the glass cloth.

[0133] <Preparation of prepreg samples> 45 parts by mass of polyphenylene ether (manufactured by SABIC, Noryl SA9000), 10 parts by mass of triallyl isocyanurate, 45 parts by mass of toluene, and 0.6 parts by mass of 1,3 - di(tert - butylisopropylbenzene) were added to a stainless steel container and stirred at room temperature for 1 hour to prepare a varnish. The prepared varnish was impregnated with the glass cloth obtained in each of the examples and comparative examples, and then dried at 115°C for 1 minute. Thereby, prepreg samples were obtained.

[0134] <Malfunction performance test> Two copper foils with a thickness of 18 μm were used to sandwich both sides of the two prepregs obtained above. And at 200°C, 40 kg / cm 2It was heated and pressurized for 2 hours to cure it, thereby fabricating a substrate. Thereafter, a copper wiring pattern with a line / space (L / S) of 10 μm was fabricated on the substrate, and 30 DRAMs were mounted so as to be electrically connected to such a wiring pattern. The substrate on which the DRAMs were mounted was continuously driven for 1000 hours under the conditions of a temperature of 150°C and a frequency of 10 GHz. Based on this result, the malfunction performance due to uranium and thorium contained in the glass fiber was evaluated. (Evaluation Criteria) A: The number of malfunctions of the DRAM is 0. B: The number of malfunctions of the DRAM is 1 - 2. C: The number of malfunctions of the DRAM is 3 - 4. D: The number of malfunctions of the DRAM is 5 - 6. E: The number of malfunctions of the DRAM is 7 - 8. F: The number of malfunctions of the DRAM is 9. G: The number of malfunctions of the DRAM is 10 or more.

[0135] 《Examples and Comparative Examples》 〈Manufacture of Glass Fiber 1 and Its Package〉 Using a quartz glass rod (diameter = 1 mm) with a silicon content of 99.92 mass% and a total content of uranium and thorium of 0.103 ppm, glass fiber was manufactured. The quartz glass rod was fed into a heating furnace set at a temperature of 1970°C filled with a sufficient amount of argon gas, and by heating and stretching, glass fiber with a diameter of 5.0 μm and 50 filaments was manufactured. For each of the heated and stretched glass filaments, a reduction treatment (annealing treatment) of the residual stress present in the glass filament was performed by passing it through a heating furnace set at a temperature of 1500°C for 1 second. The annealed glass filaments were aligned, and after applying a sizing agent using starch as the main agent with an applicator and aggregating them, they were wound around a collet to obtain a glass filament bundle (glass strand). The obtained filament bundle was twisted in the z-direction at a pitch of 0.8 turns / 25 mm using a twisting machine and wound around a bobbin to obtain glass fiber 1 and its package, respectively.

[0136] <Manufacture of Glass Fiber 2 and Its Package> A glass fiber 2 and its package were obtained in the same manner as glass fiber 1, except that a quartz glass rod (diameter = 1 mm) with a silicon content of 99.98% by mass and a total content of uranium and thorium of 0.0036 ppm was used.

[0137] <Manufacture of Glass Fiber 3 and Its Package> A glass fiber 3 and its package were obtained in the same manner as glass fiber 1, except that a quartz glass rod (diameter = 1 mm) with a silicon content of 99.90% by mass and a total content of uranium and thorium of 0.204 ppm was used.

[0138] <Manufacture of Glass Fiber 4 and Its Package> A glass fiber 4 and its package were obtained in the same manner as glass fiber 1, except that a quartz glass rod (diameter = 1 mm) with a silicon content of 99.85% by mass and a total content of uranium and thorium of 0.389 ppm was used.

[0139] <Manufacture of Glass Fiber 5 and Its Package> A glass fiber 5 and its package were obtained in the same manner as in Example 1, except that the glass rod was heat-drawn so that the number of filaments became 200.

[0140] <Manufacture of Glass Fiber 6 and Its Package> A glass fiber 6 and its package were obtained in the same manner as in Example 2, except that the glass rod was heat-drawn so that the number of filaments became 200.

[0141] <Manufacture of Glass Fiber 7 and Its Package> A glass fiber 7 and its package were obtained in the same manner as in Example 1, except that twisting was applied at a pitch of 0.4 turns / 25 mm in the z direction.

[0142] <Manufacture of Glass Fiber 8 and Its Package> The glass yarn 8 and its package were obtained in the same manner as in Example 1, except that the temperature for annealing the glass filaments was set at 1200°C.

[0143] <Manufacture of Glass Yarn 9 and Its Package> The glass yarn 9 and its package were obtained in the same manner as in Example 2, except that the temperature for annealing the glass filaments was set at 1200°C.

[0144] <Manufacture of Glass Yarn 10 and Its Package> The glass yarn 10 and its package were obtained in the same manner as in Example 1, except that the glass filaments were not annealed.

[0145] <Manufacture of Glass Yarn 11 and Its Package> The glass yarn 11 and its package were obtained in the same manner as the glass yarn 1, except that a quartz glass rod (diameter = 1 mm) with a silicon content of 99.70% by mass and a total content of uranium and thorium of 0.561 ppm was used.

[0146] <Manufacture of Glass Yarn 12> The glass was processed in the same manner as in Example 1, except that the temperature for annealing the glass filaments was set at 2000°C. However, during the annealing process, a plurality of glass filaments were cut, and therefore, the glass yarn and its package could not be obtained.

[0147] <Manufacture of Glass Yarn 13 and Its Package> The glass yarn 13 and its package were obtained in the same manner as the glass yarn 1, except that a quartz glass rod (diameter = 1 mm) with a silicon content of 99.99% by mass and a total content of uranium and thorium of 0.0017 ppm was used.

[0148] <Manufacture of Glass Yarn 14 and Its Package> A fused silica rod (diameter = 1 mm) with a silicon content of 99.91% by mass and a total content of uranium and thorium of 0.09 ppm was used. Except for this point, glass filaments 14 and their packages were obtained in the same manner as glass filament 1.

[0149] <Manufacture of Glass Filament 15 and Its Package> A fused silica rod (diameter = 1 mm) with a silicon content of 99.99% by mass and a total content of uranium and thorium of 0.0006 ppm was used. Except for this point, glass filaments 15 and their packages were obtained in the same manner as glass filament 1.

[0150] <Manufacture of Glass Filament 16 and Its Package> A fused silica rod (diameter = 1 mm) with a silicon content of 99.99% by mass and a total content of uranium and thorium of 0.0010 ppm was used. Except for this point, glass filaments 16 and their packages were obtained in the same manner as glass filament 1.

[0151] <Manufacture of Glass Filament 17 and Its Package> A fused silica rod (diameter = 1 mm) with a silicon content of 99.98% by mass and a total content of uranium and thorium of 0.0022 ppm was used. Except for this point, glass filaments 17 and their packages were obtained in the same manner as glass filament 1.

[0152] <Manufacture of Glass Filament 18 and Its Package> A fused silica rod (diameter = 1 mm) with a silicon content of 99.93% by mass and a total content of uranium and thorium of 0.03 ppm was used. Except for this point, glass filaments 18 and their packages were obtained in the same manner as glass filament 1.

[0153] <Example 1> Glass yarn 1 was used as the warp and weft yarns. In the warp warping process, the warp yarns were aligned at a line speed of 60 m / min, and a room beam subjected to secondary sizing treatment with a PVA sizing agent was produced. Subsequently, using an air jet loom, 2000 m of a raw glass cloth having a plain weave structure with a warp density of 66 yarns / 25 mm, a weft density of 68 yarns / 25 mm, and a cross width of 1300 mm was woven. In the weaving process, since the twist number of the weft yarn can be adjusted according to the loom conditions, the main nozzle pressure and the sub-nozzle angle of the loom were adjusted so that the twist number of the weft yarn was 0.6 turns / 25 mm in the z direction.

[0154] The obtained raw glass cloth was washed with ion-exchanged water and then dried. Thereby, alkali metal ions and the like adhering to the cloth surface were removed. Subsequently, it was heat-deoiled at 1000 °C for 15 seconds (heat-deoiling step). Subsequently, a treatment liquid in which 3-methacryloxypropyltrimethoxysilane (silane coupling agent A); Z6030 (manufactured by Dow Corning Toray Co., Ltd.) was dispersed at 0.3 mass% was prepared in pure water adjusted to pH = 3 with acetic acid. The cloth was immersed in the treatment liquid at a line tension of 100 N and a line speed of 15 m / min (surface treatment step). After squeezing out the treatment liquid from the cloth, it was heated and dried at 130 °C for 60 seconds, thereby fixing the silane coupling agent (fixing step).

[0155] The dried cloth was irradiated with ultrasonic waves in water at a frequency of 25 kHz and an output of 0.50 W / cm 2 Thereafter, while reducing the excess silane coupling agent physically attached to the cloth with a columnar flow discharged from a high-pressure water spray of 1.4 MPa, the cloth was subjected to a fibrillating treatment (fibrillating step). Thereafter, the cloth was dried at 130 °C for 1 minute (drying step). Thus, the glass cloth of Example 1 was obtained.

[0156] 〈Examples 2 to 16 and Comparative Example 1〉 A glass cloth was obtained in the same manner as in Example 1, except that the items described in the following table were changed as shown in the following table.

[0157] For the examples and comparative examples, the manufacturing conditions and evaluation results are shown in the following table. Note that using the glass cloth of the examples, prepregs, printed wiring boards, integrated circuits, and electronic devices could be fabricated by conventional methods.

[0158] [Table 1]

[0159] [Table 2]

[0160] [Table 3]

[0161] [Table 4]

[0162] [Table 5]

[0163] [Table 6]

[0164] From the above table, it was confirmed that according to the examples, a glass cloth can be provided that can improve flatness and also reduce the occurrence frequency of fluff. Further, from the above table, it was also confirmed that suitably controlling the total content of uranium and thorium in the glass fiber is advantageous for the <malfunction performance test> evaluation.

Industrial Applicability

[0165] The present disclosure can be suitably used in the fields related to glass yarns, glass cloths, prepregs, printed wiring boards, and methods for manufacturing glass cloths.

Description of Signs

[0166] 1: Measuring table 2: Glass cloth sample

Claims

1. A glass cloth made of glass yarn, The silicon (Si) content in the glass yarn is silicon dioxide (SiO ２ ) is 95.0 to 100 mass% in terms of fiber length, and the Snarl index of the glass yarn is 400 mm or less; The glass yarn has a range defined by the following formulas (A), (B), and (C): (A) x+y+z=100% by mass (B) x≧99.5% by mass (C) 0.0003ppm≦y≦0.50ppm x: silicon content calculated as silicon dioxide (SiO 2 ) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium Glass cloth containing glass yarn.

2. A glass cloth made of glass yarn, The bulk dielectric tangent at 10 GHz of the glass constituting the glass yarn is in the range of 0.001 or less, and the Snarl index of the glass yarn is 400 mm or less; The glass yarn has a range defined by the following formulas (A), (B), and (C): (A) x+y+z=100% by mass (B) x≧99.5% by mass (C) 0.0003ppm≦y≦0.50ppm x: silicon content calculated as silicon dioxide (SiO 2 ) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium Glass cloth containing glass yarn.

3. 3. The glass cloth according to claim 1, wherein the glass yarn has a Snarl index of 70 mm or more.

4. The glass cloth according to claim 1 or 2, wherein the range of x is 99.6 mass% or more.

5. The glass cloth according to claim 1 or 2, wherein the range of x is 99.9 mass% or more.

6. 3. The glass cloth according to claim 1, wherein the glass yarn is treated with a surface treatment agent containing a silane coupling agent.

7. The surface treatment agent is represented by the following formula (1): X (R) 3-n Yes n ・・・(1) (In formula (1), X is an organic functional group having at least one of an amino group and an unsaturated double bond group having radical reactivity, each Y is independently an alkoxy group, n is an integer of 1 to 3, and each R is independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group.) The glass cloth according to claim 6, comprising the silane coupling agent represented by the formula:

8. 8. The glass cloth according to claim 7, wherein X in the formula (1) is an organic functional group that does not form a salt with an ionic compound.

9. 8. The glass cloth according to claim 7, wherein X in the formula (1) does not include an amine and / or an ammonium cation.

10. 8. The glass cloth according to claim 7, wherein X in the formula (1) is an organic functional group having a methacryloxy group and / or an acryloxy group.

11. 3. The glass cloth according to claim 1, wherein the absolute value of the number of twists of the glass yarns is in the range of 0.5 to 1.5 twists / 25 mm.

12. The glass cloth has the glass yarn as a warp yarn and a weft yarn, 3. The glass cloth according to claim 1, wherein an absolute value of the difference between the number of twists of the warp yarns and the number of twists of the weft yarns is in the range of 0.01 to 0.70 turns / 25 mm.

13. The glass cloth according to claim 1 or 2, wherein the glass cloth has a thickness of 60 μm or less.

14. The glass cloth according to claim 1 or 2, which is for a printed wiring board.

15. A prepreg comprising the glass cloth according to claim 1 or 2 and a thermosetting resin.

16. A printed wiring board comprising the prepreg of claim 15.

17. 17. An integrated circuit comprising the printed wiring board of claim 16.

18. An electronic device comprising the printed wiring board according to claim 16.

19. A method for producing a glass cloth, comprising the steps of: The silicon (Si) content in the glass yarn is silicon dioxide (SiO ２ ) is in the range of 95.0 to 100 mass %, The glass yarn has a Snarl index of 400 mm or less, and the glass yarn is used to obtain a glass cloth. The glass yarn has a range defined by the following formulas (A), (B), and (C): (A) x+y+z=100% by mass (B) x≧99.5% by mass (C) 0.0003ppm≦y≦0.50ppm x: silicon content calculated as silicon dioxide (SiO 2 ) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium obtaining a glass cloth using the glass yarn satisfying the above-mentioned requirement.

20. A method for producing a glass cloth, comprising the steps of: The bulk dielectric tangent of the glass constituting the glass yarn at 10 GHz is in the range of 0.001 or less, The glass yarn has a Snarl index of 400 mm or less, and the glass yarn is used to obtain a glass cloth. The glass yarn has a range defined by the following formulas (A), (B), and (C): (A) x+y+z=100% by mass (B) x≧99.5% by mass (C) 0.0003ppm≦y≦0.50ppm x: silicon content calculated as silicon dioxide (SiO 2 ) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium obtaining a glass cloth using the glass yarn satisfying the above-mentioned requirement.

21. The method for producing a glass cloth according to claim 19 or 20, wherein the glass yarn has a Snarl index of 70 mm or more.

22. A step of warping the glass yarn used as a warp yarn (warp yarn warping step); and A step of weaving using the glass yarn (weaving step); Including, The method for producing a glass cloth according to claim 19 or 20, wherein an absolute value of the number of twists of the glass yarns is adjusted to a range of 0.5 to 1.5 twists / 25 mm in the warp warping step and / or the weaving step.

23. The glass cloth has the glass yarn as a warp yarn and a weft yarn, The method for producing a glass cloth according to claim 22, further comprising a step of adjusting the number of twists of the weft yarn so that an absolute value of a difference between the number of twists of the warp yarn and the number of twists of the weft yarn is in a range of 0.01 to 0.70 turns / 25 mm.

24. The method for producing a glass cloth according to claim 22, wherein the warp warping step and / or the weaving step are carried out using the glass yarn having a value obtained by dividing the yarn width (μm) of the glass yarn by TEX in the range of 10 to 30.

25. A glass yarn package having a core material and a glass yarn wound around the core material, The silicon (Si) content in the glass yarn is silicon dioxide (SiO ２ ) is 95.0 to 100 mass% in terms of fiber length, and the Snarl index of the glass yarn is 400 mm or less; The glass yarn has a range described by the following formulas (A), (B), and (C): (A) x+y+z=100% by mass (B) x≧99.5% by mass (C) 0.0003ppm≦y≦0.50ppm x: silicon content calculated as silicon dioxide (SiO 2 ) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium Meet the glass yarn package.

26. 26. The glass yarn package according to claim 25, wherein the glass yarn has a Snarl index of 70 mm or more.

27. The glass yarn package according to claim 25 or 26, wherein the absolute value of the twist number of the glass yarn is in the range of 0.5 to 1.5 turns / 25 mm.

28. The glass yarn package according to claim 25 or 26, wherein the value obtained by dividing the yarn width (μm) of the glass yarn by TEX is in the range of 10 to 30.

29. A glass yarn used in weaving a glass cloth, The silicon (Si) content in the glass yarn is silicon dioxide (SiO ２ ) is 95.0 to 100 mass% in terms of fiber length, and the Snarl index of the glass yarn is 400 mm or less; The glass yarn has a range defined by the following formulas (A), (B), and (C): (A) x+y+z=100% by mass (B) x≧99.5% by mass (C) 0.0003ppm≦y≦0.50ppm x: silicon content calculated as silicon dioxide (SiO 2 ) y: Total content of uranium and thorium z: Total content of elements other than silicon, uranium, and thorium Meet the glass thread.

30. 30. The glass thread according to claim 29, wherein the glass thread has a Snarl index of 70 mm or more.

31. The glass thread according to claim 29 or 30, wherein y, which represents the total content of uranium and thorium, is in the range of 0.0003 to 0.0010 ppm.

32. The glass thread according to claim 29 or 30, wherein y, which represents the total content of uranium and thorium, is in the range of more than 0.0010 and not more than 0.0015 ppm.

33. The glass thread according to claim 29 or 30, wherein y, which represents the total content of uranium and thorium, is in the range of more than 0.0015 and not more than 0.0018 ppm.

34. The glass thread according to claim 29 or 30, wherein y, which represents the total content of uranium and thorium, is in the range of more than 0.0018 and not more than 0.0035 ppm.

35. The glass thread according to claim 29 or 30, wherein y, which represents the total content of uranium and thorium, is in the range of more than 0.0035 and not more than 0.0040 ppm.

36. The glass thread according to claim 29 or 30, wherein y, which represents the total content of uranium and thorium, is in the range of more than 0.0040 and not more than 0.09 ppm.

37. The glass thread according to claim 29 or 30, wherein y, which represents the total content of uranium and thorium, is in the range of more than 0.09 and not more than 0.12 ppm.

38. The glass thread according to claim 29 or 30, wherein y, which represents the total content of uranium and thorium, is in the range of more than 0.12 and not more than 0.50 ppm.

39. The glass thread according to claim 29 or 30, wherein the Snarl index of the glass thread is in the range of 330 to 400 mm.

40. The glass thread according to claim 29 or 30, wherein the Snarl index of the glass thread is in the range of 300 to 329 mm.

41. The glass thread according to claim 29 or 30, wherein the Snarl index of the glass thread is in the range of 220 to 299 mm.

42. The glass thread according to claim 29 or 30, wherein the Snarl index of the glass thread is in the range of 200 to 219 mm.

43. The glass thread according to claim 29 or 30, wherein the Snarl index of the glass thread is in the range of 125 to 199 mm.

44. The glass thread according to claim 29 or 30, wherein the Snarl index of the glass thread is in the range of 110 to 124 mm.

45. 31. The glass thread according to claim 29 or 30, wherein the glass thread has a Snarl index of 110 mm or less.

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