Glass yarn, glass cloth, prepreg and printed wiring board

Abstract

This invention relates to a glass cloth comprising glass yarn, wherein the silicon (Si) content in the glass yarn is primarily composed of silicon dioxide (SiO₂). 2) The conversion percentage is 95.0% to 100% by mass, and the twist index of the glass yarn is 400 mm or less. Alternatively, the bulk dielectric loss factor of the glass constituting the glass yarn is 0.001 or less at 10 GHz, and the twist index of the glass yarn is 400 mm or less.

Description

[Technical Field]

[0001] This invention relates to a glass yarn, glass cloth, prepreg, and printed wiring board, etc. [Previous Technology]

[0002] Currently, the performance of information terminals such as smartphones is constantly improving, and high-speed communication, represented by 5G communication, is continuously advancing. Against this backdrop, especially for printed circuit boards (PCBs) used in high-speed communication, there is a desire not only to improve the heat resistance required previously, but also to further improve the dielectric properties of their insulating materials (e.g., reducing the dielectric loss factor). Similarly, there is a desire to improve the dielectric properties of the prepreg used in the insulating materials of PCBs, as well as the glass yarn and glass cloth contained within the prepreg.

[0003] In order to achieve low dielectric properties in insulating materials, it is known to use a method of constructing an insulating material by impregnating a low dielectric resin (hereinafter referred to as "matrix resin") into glass cloth. Patent documents 1 and 2 describe that polyphenylene ethers with end-modified vinyl or methacryloxy groups are more advantageous in terms of low dielectric properties and heat resistance; and that the modified polyphenylene ether is used as the matrix resin.

[0004] Furthermore, reports have been made of glass wire bundles with a winding density of 0.10 strands / cm or less, having a curvature radius of less than 5 mm and a bending angle of less than 120 degrees, used for purposes such as improving the flatness of the glass cloth and stabilizing the signal transmission speed (see, for example, Patent Document 3). Patent Document 3 describes that by using a cylindrical grinding machine to perform cylindrical grinding on a silica glass ingot, a silica glass ingot with the desired sphericity can be obtained, and by using such a silica glass ingot with the desired sphericity, glass filaments as raw materials for glass wire bundles can be obtained.

[0005] Furthermore, the report includes an invention that uses a silane coupling agent to surface treat glass cloth and adjusts the loss on ignition value of the glass cloth to 0.13 to 0.40% by mass (see, for example, Patent Document 4). Patent Document 4 describes the following: For glass cloth woven from glass yarn containing glass filaments with a silicon dioxide (SiO2) composition of 98 to 100% by mass, by adjusting the loss on ignition value of the glass cloth to the above range, the insulation reliability can be improved, and the generation of fuzz in the glass cloth can be suppressed.

[0006] Furthermore, as an invention in the same technical field, the invention described in Patent Document 5 is reported. [Prior Art Documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2019 / 065940 [Patent Document 2] International Publication No. 2019 / 065941 [Patent Document 3] Japanese Patent Application Publication No. 2020-90432 [Patent Document 4] Japanese Patent Application Publication No. 2018-127747 [Patent Document 5] International Publication No. 2022 / 215288 [Summary of the Invention]

[0008] [Problem to be Solved by the Invention] However, the invention described in Patent Document 3 has the following problem: the yield is reduced because it requires cylindrical grinding of silicon dioxide glass ingots. Therefore, there is a strong demand for a technology that improves the flatness of glass cloth without special processing such as cylindrical grinding.

[0009] Furthermore, as described in Patent Document 4, the invention that includes surface treatment of glass cloth using a silane coupling agent has the following problem: when the silane coupling agent is not intended to remain on the glass surface, the dielectric loss factor of the glass cloth increases (see, for example, Patent Document 5 above). Therefore, there is a strong demand for the development of a technique to suppress the fuzzing of glass cloth by means other than adjusting the loss on ignition value.

[0010] The object of the present invention is to provide a glass cloth with excellent flatness and reduced frequency of fuzz generation. Another object of the present invention is to provide a method for manufacturing the glass cloth, a glass yarn roll, and glass yarn capable of providing the glass cloth. Furthermore, another object of the present invention is to provide a prepreg, printed circuit board, integrated circuit, and electronic device using the glass cloth. [Technical Means for Solving the Problem]

[0011] Examples of embodiments of the present invention are described below. [1] A glass cloth which contains glass yarn, the silicon (Si) content in the above-mentioned glass yarn is 95.0 to 100 mass% converted by silicon dioxide (SiO [2] A glass fabric which comprises a glass yarn, the body dielectric loss factor of the glass constituting the glass yarn at 10 GHz is in the range below 0.001, and the kinking index of the said glass yarn is less than 400 mm. [3] The glass fabric as noted in items 1 or 2, wherein the kinking index of the said glass yarn is 70 mm or more. [4] The glass cloth as described in item 1 or 2, wherein the above glass yarn contains glass yarn that satisfies the ranges described in equations (A), (B), and (C) below, (A) x + y + z = 100 mass% (B) x ≥ 99.5 mass % (C) 0.0003 ppm ≤ y ≤ 0.50 ppm x: 2) Silicon dioxide content y: Combined contents of uranium and titanium z: Combined contents of elements other than silicon, uranium, and thorium. [5] The glass cloth as noted in item 4, where the range of the above x is in the range above 99.6% by mass. [6] The glass cloth as noted in item 4, where the range of the above x is in the range above 99.9% by mass. [7] The glass cloth as described in any one of items 1 to 6, wherein the said glass yarn is treated with a surface treatment comprising a silane coupling agent. [8] The glass cloth as described in item 7, wherein the above surface treatment agent comprises the above silane coupling agent shown in formula (1) below: X(R) 3-nSiY n・・・(1) (In formula (1) , X is an organic functional group of at least one having an amine group, and an unsaturated double bond with radical reactivity, Y is each independently an alkoxy group, n is an integer above 1 and below 3, and R is each independently a group selected from the group composed of methyl, ethyl, and phenyl group). [9] The glass cloth as noted in item 8, where X in formula (1) above is the organic functional group that has not formed a salt with the ionic compound.

[10] The glass cloth as noted in items 8 or 9, wherein X in formula (1) above does not comprise an amine and / or ammonium cation.

[11] The glass cloth as described in any one of items 8 to 10, wherein X in formula (1) above is an organic functional group having a methacryloyloxy group and / or an acrylamide oxygen group.

[12] The glass cloth as described in any one of items 1 to 11, wherein the absolute value of the jerk degree of the said glass yarn is in the range of 0.5 to 1.5 times / 25 mm.

[13] The glass fabric as described in any of items 1 to 12, wherein the said glass fabric has the said glass yarn as warp and weft yarn, and the absolute value of the difference in the degree of the said warp and the said weft yarn is in the range of 0.01 to 0.70 times / 25 mm.

[14] The glass cloth as described in any one of items 1 to 13, wherein the thickness of the said glass cloth is less than 60 μm.

[15] The glass cloth as described in any of items 1 to 14, which is used for printing patch panels.

[16] A prepreg containing a glass cloth as described in any one of items 1 to 15, and thermosetting resin.

[17] A printed patch panel which contains a prepreg as described in item 16 .

[18] An integrated circuit comprising a printed wiring board as described in item 17 .

[19] An electronic machine comprising a printed patch panel as described in item 17 .

[20] A method of fabrication of glass cloth, which includes the step of obtaining a glass cloth using the following glass yarn, the silicon (Si) content in the range of 95.0–100 mass% converted by silicon dioxide (SiO

[21] A method of fabrication of glass cloth, which comprises the step of obtaining a glass cloth using the following glass yarn, the body dielectric loss factor of the glass constituting the glass yarn at 10 GHz is in the range of 0.001 or less, and the kinking index of the said glass yarn is 400 mm or less.

[22] The method of fabrication of glass cloth as noted in items 20 or 21, wherein the kinking index of the said glass yarn is 70 mm or more.

[23] The method of manufacturing glass cloth as described in item 20 or 21, which includes the steps of obtaining glass cloth using the above glass yarn satisfying the ranges described in formulas (A), (B), and (C) below: (A) x + y + z = 100% by mass (B) x≥99.5% by mass (C) 0.0003 ppm for Si y: Combined contents of uranium and titanium z: Combined contents of elements other than silicon, uranium, and thorium.

[24] The method of manufacturing glass cloth as described in any of items 20 to 23, which includes the step of warping the said glass yarn being used as warp yarn (warp warping step), and the step of weaving using the said glass yarn (weaving step), adjusting the absolute value of the stiffness of the said glass yarn to the range of 0.5 to 5

[25] As described in item 24 for the manufacturing method of glass cloth, wherein the glass cloth has the above glass yarn as warp and weft yarn, the method of manufacturing the glass cloth includes the step of adjusting the stiffness of the said weft yarn so that the absolute value of the difference between the said warp and the said weft degree becomes in the range of 0.01 to 0.70 times / 25 mm.

[26] The method of fabrication of the glass cloth as described in items 24 or 25, wherein the glass yarn of the above-mentioned glass yarn divided by the value obtained by TEX in the range of 10 to 30, performs the warp yarn-tweaking step described above and / or the weaving step described above.

[27] A glass yarn curling body, which has a core material and a glass yarn wound in the said core material, the silicon (Si) content in the said glass yarn is 95.0–100 mass% converted by silicon dioxide (SiO

[28] The glass yarn rolled body as described in item 27, wherein the kinking index of the said glass yarn is 70 mm or more.

[29] The glass yarn rolled body as described in items 27 or 28, wherein the above glass yarn satisfies the ranges described in equations (A), (B), and (C) below: (A) x + y + z = 100 mass% (B) x ≥ 99.5 mass % (C) 0.0003 ppm ≤ y ≤ 0.50 ppm x O: 2 silicon dioxide content when calculated as Si) y: Combined contents of uranium and titanium z: Combined contents of elements other than silicon, uranium, and thorium.

[30] The glass yarn rolled body as described in any one of items 27 to 29, wherein the absolute value of the stiffness of the said glass yarn is in the range of 0.5–1.5 times / 25 mm.

[31] The glass yarn roll body as described in items 27 or 28, wherein the value obtained by dividing the yarn width of the said glass yarn by TEX is in the range of 10–30.

[32] A glass yarn, which is used in the weaver of glass cloth, the silicon (Si) content in the above-mentioned glass yarn is 95.0 to 100 mass% by conversion of silicon dioxide (SiO

[33] The glass yarn as noted in item 32, wherein the kinking index of the said glass yarn is 70 mm or more.

[34] The glass yarn as described in items 32 or 33, wherein the said glass yarn satisfies the ranges described in Equations (A), (B), and (C) below: (A) x + y + z = 100% by mass (B) x ≥ 99.5% by mass (C) z: Combined content of elements other than silicon, uranium, and thorium.

[35] As in the glass yarn as noted in item 34, where the y indicating the combined amount of the contents of uranium and titanium described above is in the range of 0.0003 to 0.0010 ppm.

[36] The glass yarn as noted in item 34, where the y of the combined amount of the contents of uranium and titanium indicated above is in the range of more than 0.0010 and below 0.0015 ppm.

[37] The glass yarn as noted in item 34, wherein the y of the combined amount of the contents of uranium and titanium indicated above is in the range of more than 0.0015 and below 0.0018 ppm.

[38] The glass yarn as noted in item 34, wherein the y of the combined amount of the contents of uranium and titanium indicated above is in the range of more than 0.0018 and below 0.0035 ppm.

[39] The glass yarn described in Item 34, wherein the summation y of the uranium and thorium content is greater than 0.0035 and less than 0.0040 ppm.

[40] The glass yarn described in Item 34, wherein the summation y of the uranium and thorium content is greater than 0.0040 and less than 0.09 ppm.

[41] The glass yarn described in Item 34, wherein the summation y of the uranium and thorium content is greater than 0.09 and less than 0.12 ppm.

[42] The glass yarn described in Item 34, wherein the summation y of the uranium and thorium content is greater than 0.12 and less than 0.50 ppm.

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

[44] The glass yarn described in any one of items 32 to 42, wherein the twist index of the glass yarn is in the range of 300 to 329 mm.

[45] The glass yarn described in any one of items 32 to 42, wherein the twist index of the glass yarn is in the range of 220 to 299 mm.

[46] The glass yarn described in any one of items 32 to 42, wherein the twist index of the glass yarn is in the range of 200 to 219 mm.

[47] The glass yarn described in any one of items 32 to 42, wherein the twist index of the glass yarn is in the range of 125 to 199 mm.

[48] The glass yarn described in any one of items 32 to 42, wherein the twist index of the glass yarn is in the range of 110 to 124 mm.

[49] The glass yarn described in any one of items 32 to 42, wherein the twist index of the glass yarn is less than 110 mm. [Effects of the Invention].

[0012] According to the present invention, a glass cloth with excellent flatness and reduced frequency of fuzz generation can be provided. Furthermore, according to the present invention, a method for manufacturing the glass cloth, a glass yarn roll, and glass yarn can be provided. Furthermore, according to the present invention, a prepreg, a printed circuit board, an integrated circuit, and an electronic device using the glass cloth can be provided.

Implementation Method

[0014] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments, and various changes can be made without departing from its spirit.

[0015] In this specification, in the case where a structure represented by the same symbol exists in the same formula, the structures may be selected separately and independently as long as they are not otherwise specified, again, they may be identical or different from each other. Even in the case where there are plurals of structures represented by the same sign in mutually different formulas, the structures may be chosen separately and independently, again, they may be identical or different from each other, provided that no other provision is provided. Furthermore, in this specification, an upper or lower limit value in a numerical range recorded in stages may be substituted for an upper or lower limit value in a corresponding numerical range recorded in other stages and, in turn, a corresponding value as described in embodiments. Further, in this specification, with respect to "step," not only separate steps are included, but in cases in which no other step cannot be distinctly distinguished, as long as the function of the step will be accomplished. In what is shown in the diagram, the reduced proportions, shapes and lengths are sometimes exaggerated in order to seek further clarity.

[0016] <<Glass Cloth>> <Overall Configuration> The glass cloth of the present invention contains glass yarn, the silicon (Si) content in the above glass yarn is 95.0 to 100 mass% by conversion of silicon dioxide (SiO

[0017] Also, where the glass cloth of the present invention contains a glass yarn, the body dielectric loss factor of the glass constituting the glass yarn at 10 GHz is in the range of 0.001 or less, and the kinking index of the glass yarn is in the range of 400 mm or less.

[0018] The inventors and others found that the glass fabric obtained by using glass yarn that is conducive to improving the dielectric characteristics of the glass fabric, such as the glass yarn described in (1) and / or (2) below, is prone to generate residual stress and that such glass yarn has a tendency to have a higher kink index. The inventors and others further made it clear that the higher the kink index of the glass yarn used in the glass cloth, the more adverse effects it will have on the flatness (degree of warping) of the glass cloth. (1) The silicon (Si) content in the glass yarn is 95.0 to 100% of the mass of glass yarn converted by silicon dioxide (SiO

[0019] The term snarl here refers to the distortion produced in that yarn due to the desire of the added yarn to spin back, and in this instruction, the higher the kink index, means the easier it is to produce kinks. Further, in JIS-L-0210:1981 of 3.1, item 1113, kink is defined as “the entanglement of yarns resulting from an adder when the yarn through the appliqué is loosened.” In that regard, the effect of kink index on the quality of glass fabric has not been previously studied.

[0020] Also, for glass yarns (referred to as "glass yarn rollers") in the state of the glass yarn being wound in a core material (in the same state as a winding cylinder), the present inventors and others have clearly stated that the higher the kink index of the glass yarn, the easier it is for the glass yarn to loosen on one side of the surface of the winding cylinder when removing the glass yarn from the winding cylinder. In particular, the present inventors and others also found that in the step of warping the glass yarn used as the warp yarn of the glass cloth (warp yarn warping step), the relief speed of the glass yarn is slower compared to the step of weaving using the glass yarn (weaving step).

[0021] Therefore, the present inventors and others conducted a study based on the view of reducing the kink index, and as a result, it was found to be able to adjust the kink index according to the spinning conditions of the glass yarn. In a better state sample, it was possible to prepare glass yarn from a glass rod with a silicon content of 99.5% or more by mass, at this time, it was possible to perform annealing treatment to reduce the residual stress generated in the glass yarn after heating extension of the glass rod (in the one-state sample, the residual stress was eliminated). According to the present invention, a glass yarn capable of being controlled using the kink index provides a glass cloth capable of achieving an improvement in flatness and also a reduction in the frequency of hair feather generation.

[0022] The unit area weight of the glass cloth (the mass of the glass cloth) is preferably 8 to 250 g / m2, preferably 8 to 100 g / m The effect of the present invention is easily obtained if the weight per unit area of ​​the glass cloth is within the above range.

[0023] The thickness of the glass cloth is preferably less than 60 μm, more preferably less than 55 μm, and further preferably less than 50 μm. The effect of the present invention is easily obtained if the thickness of the glass cloth is within the above range. The thickness of the glass cloth may exceed 0, be more than 5 μm, or more than 5 μm.

[0024] <Glass yarn> The kink index of glass yarn is in the range of 400 mm or less. If an addition is applied to the yarn, the unclinging torque of the desire to return the yarn will be produced, that is, at this time, there is a situation where the twisting of the yarn is produced. In this specification, such a kink is referred to as a “kink”, again, as an indicator of the ease of generating such kink, for example, a kink index as described in JIS L1095 may be used.

[0025] It is known that glass wire harnesses (glass yarns) suitable for use in printed wiring boards are obtained by the following method: the glass obtained by melting glass in a melting furnace is extruded from a nozzle to obtain glass filaments with a diameter of several μm, and then the filaments are processed.

[0026] On the other hand, quartz glass with a silicon (Si) content of 95.0% to 100% by mass (converted to silicon dioxide (SiO2)) has a much higher melting point than other glasses. Therefore, it differs from the aforementioned E-glass wire bundles in that glass filaments, which are its raw materials, are obtained by heating and stretching a quartz glass rod (quartz glass ingot). When a quartz glass rod is heated and stretched, the siloxane bonds constituting the glass align along the stretching direction, and in this case, residual stress is easily generated in the obtained glass filaments.

[0027] The inventors have discovered that due to this residual stress, "kinking," which was not considered a problem in previous glass wire bundles, can adversely affect the fuzz quality and flatness of the glass cloth. Specifically, the higher the kinking index of the glass wire bundle, the easier it is for the glass yarn to come into contact with the surface of the winding bobbin when unwinding the glass yarn from the bobbin during the warping of the glass cloth. As a result, fuzz is more likely to form on the surface of the glass cloth. Furthermore, even when the glass wire bundle is in its glass cloth state, the yarn undulation is stronger with a higher kinking index, which can easily have an adverse effect on the flatness (warping) of the glass cloth.

[0028] Regarding the "kink" that was not considered a problem in the previous glass wire bundles, from the viewpoint of further reducing the kink index of the quartz glass wire bundles, a method of annealing the glass filaments or glass yarns immediately after heating and stretching them is preferred. This method is relatively simple and is also more advantageous in providing glass cloth with excellent hair quality and flatness.

[0029] The inventors conducted research and found that by setting the twist index of the glass yarn to 400 mm or less, the frequency of fuzz generation on the surface of the glass cloth can be reduced, and warping can be performed. From the viewpoint of easily obtaining the effects of the present invention, the twist index of the glass yarn is preferably 70 to 400 mm. From the viewpoint of suppressing fuzz on the glass surface, the upper limit of the twist index is preferably 380 mm or less, more preferably 370 mm or less, further preferably 350 mm or less, further preferably 330 mm or less, and especially preferably 310 mm or less. For example, it can also be 300 mm or less, 250 mm or less, 200 mm or less, 150 mm or less, or 100 mm or less. The lower limit of the twist index, which can be arbitrarily combined with these upper limits, can 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 mm or more. For example, from the viewpoint of easily obtaining the effects of the present invention, the twist index of the glass yarn is preferably in the range of 330-400 mm, 300-329 mm, or 220-299 mm; from the viewpoint of slightly valuing the surface hairiness of the glass cloth in addition to the productivity of the glass yarn, it is preferably in the range of 200-219 mm; from the viewpoint of even more valuing the surface hairiness of the glass cloth in addition to the productivity of the glass yarn, it is preferably in the range of 125-199 mm; from the viewpoint of further valuing the surface hairiness of the glass cloth in addition to the productivity of the glass yarn, it is even more preferably in the range of 110-124 mm; and from the viewpoint of particularly valuing the surface hairiness of the glass cloth in addition to the productivity of the glass yarn, it is especially preferably in the range of 110 mm or less, for example, 70-110 mm or less.

[0030] From the viewpoint that it is easy to obtain the effect of reducing the kink index brought about by annealing treatment, the silicon (Si) content in the glass yarn, calculated as silicon dioxide (SiO2), is preferably 99.5% by mass or more, more preferably 99.6% by mass or more, even more preferably 99.7% by mass or more, even more preferably 99.8% by mass or more, and most preferably 99.9% by mass or more and 99.95% by mass or more.

[0031] Glass cloth is obtained by weaving glass yarn (e.g., glass yarn formed by multiple glass filaments) as warp and weft yarns. Regarding the fabric structure of glass cloth, examples include plain weave, square plain weave, satin weave, and twill weave, among which plain weave is preferred.

[0032] The weaving density of warp and weft yarns is preferably 10 to 120 strands / inch (=10 to 120 strands / 25 mm), and preferably 40 to 100 strands / inch. The effect of the present invention is easily obtained if the weaving density is within the above range. The weaving densities of warp and weft yarns can be different from each other.

[0033] The glass yarn constituting the glass cloth may be obtained by including a so-called "low dielectric glass" in the raw material. The glass yarn is preferably a glass yarn containing a glass yarn that satisfies the ranges described in (A), (B), and (C), and preferably a glass yarn that satisfies the ranges described in (A), (B), and (C): (A) x + y + z = 100 mass % (B) x ≥ 99.5 mass % (C) 0.0003 ppm for Si y: Combined contents of uranium and titanium z: Combined contents of elements other than silicon, uranium, and thorium. By using glass yarns satisfying the ranges noted in (A), (B), and (C), it is easy, for example, to achieve the improvement of the dielectric characteristics of the obtained glass cloth.

[0034] In terms of the view of improving the dielectric characteristics of the obtained glass cloth, the range of x is preferably a range above 99.6 mass %, more preferably a range above 99.7 mass %

[0035] The better range of y is the range noted in (C) above, i.e., 0.0003 ppm ≤ y ≤ 0.50 ppm. Since the uranium (U) and titanium (Th) in the glass yarn may cause malaction of the memory in machines for electronic purposes, the less their combined content, the better. The present inventors and others conducted a study and the results showed that although the mechanism of action is not clear, the combined content of uranium and titanium is affected when adjusting the kink index by controlling the residual stress in the glass yarn. Namely, the present inventors and others found a characteristic phenomenon in the case of preparing glass yarns from glass rods with a silicon content of 99.5% or more by mass, namely, if the combined content of uranium and titanium is above 0.0003 ppm, it is easy to reduce the residual stress in that glass yarn. In this regard, the inventors and others also made it clear that due to the stronger dissolution force of glass yarn with higher residual stress, the kinking index of glass yarn is often higher, glass cloth made using such glass yarn is easy to warp and flatness is easy to deteriorate.

[0036] Regarding the above viewpoint, it was previously a general technical consensus to keep the total content of uranium (U) and thorium (Th) as low as possible. In this regard, from the perspective of improving the flatness of the glass cloth, the total content of uranium and thorium was not previously intentionally adjusted to be within an appropriate range. The inventors conducted intensive research and found that the higher the total content of uranium and thorium in the glass cloth, the easier it is to achieve the effect of annealing treatment to reduce the kink index in the glass cloth. From the perspective of easily obtaining the effects of the present invention, the range of y can be 0.0003 ppm ≤ y ≤ 0.50 ppm, with the lower limit preferably being 0.001 ppm or more, more preferably 0.003 ppm or more, further preferably 0.005 ppm or more, further preferably 0.007 ppm or more, and particularly preferably 0.01 ppm or more. The upper limit of y, which can be arbitrarily combined with these lower limits, is preferably below 0.45 ppm, more preferably below 0.40 ppm, further preferably below 0.35 ppm, further preferably below 0.30 ppm, and most preferably below 0.25 ppm. If y is above 0.0003 ppm, it is easy to avoid high residual stress during heating and stretching due to excessively high silicon content in the glass, thus making it easy to control the kink index of the glass yarn to below 400 mm. On the other hand, if y is below 0.50 ppm, it is easy to avoid the influence of uranium and thorium, for example, it is easy to avoid problems in use caused by memory malfunctions in electronic devices containing glass yarn in their components. Furthermore, from the viewpoint of easily improving the memory malfunction performance, y is preferably in the range of 0.0003 to 0.0010 ppm. From the perspective of easily reducing glass fiber entanglement, in addition to reducing memory malfunction performance, y is preferably in the range of more than 0.0010 and less than 0.0015 ppm. From the perspective of easily reducing glass fiber entanglement, in addition to reducing memory malfunction performance, y is preferably in the range of more than 0.0015 and less than 0.0018 ppm. From the perspective of easily reducing glass fiber entanglement, in addition to reducing memory malfunction performance, y is even more preferably in the range of more than 0.0018 and less than 0.0035 ppm. From the perspective of easily reducing glass fiber entanglement and easily refining the quartz rod, in addition to reducing memory malfunction performance, y is preferably more than 0.0035 and less than 0.0040. From the perspective that, in addition to reducing the malfunction performance of memory, it is easier to further reduce the kinking of glass yarn and make it easier to refine the quartz rod, the range below ppm is particularly favorable for y to be above 0.0040 and below 0.09 ppm.

[0037] <Bulk Dielectric Loss Factor> In this specification, the bulk dielectric loss factor refers to the dielectric loss factor obtained by measuring the raw material of glass cloth at 10 GHz using a split-cylinder resonator. The raw material of the glass cloth may be, for example, a type of glass, glass filament, glass yarn, etc. The bulk dielectric loss factor of the glass raw material constituting the glass cloth can be measured by measuring a glass plate with the same type and composition as the glass raw material and a thickness of 300 μm or less using the same method as that used to measure the dielectric loss factor of the glass cloth.

[0038] From the viewpoint of easily obtaining the effects of the present invention, the bulk dielectric loss factor at 10 GHz is preferably 0.0009 or less, more preferably 0.0008 or less, further preferably 0.0007 or less, further preferably 0.0005 or less, further preferably 0.0004 or less, particularly preferably 0.0003 or less, and most preferably 0.0002 or less. The bulk dielectric loss factor can exceed 0.

[0039] <Average Fiber Opening Degree of Glass Cloth> The average fiber opening degree of the glass cloth is preferably 38% or more, or more than 40%, more preferably more than 43%, and even more preferably more than 46%, more than 50%, more than 53%, more than 56%, or more than 60%, and most preferably more than 65%. If the average fiber opening degree of the glass cloth is 38% or more, it is possible to manufacture prepreg or printed wiring boards containing the prepreg, and it is easy to suppress the presence of air bubbles, known as pores, in the bundle of glass yarn, thereby minimizing adverse effects on the heat resistance and insulation reliability of the solder. Furthermore, if the average fiber opening degree of the glass cloth is 38% or more, it is less susceptible to the effects of glass yarn twisting, so even when using glass yarn with a relatively high twist index, it is easy to ensure the flatness of the glass cloth.

[0040] <Silane Coupling Agent> For glass yarn (including glass filaments) constituting glass cloth, it is preferable to use a silane coupling agent for surface treatment. That is, in one sample, the surface treatment agent of the glass yarn includes a silane coupling agent. As a silane coupling agent, it is preferred, for example, to include the silane coupling agent shown in the following formula (1): X(R) 3-nSiY 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 free radical reactivity, Y is independently an alkoxy group, n is an integer from 1 to 3, and R is a group selected from the group consisting of methyl, ethyl, and phenyl}.

[0041] Previously, the reasons for the increase in the dielectric loss factor of glass cloth were considered to be as follows: (i) extremely small amounts of thermally oxidized deterioration of the condenser remaining in a state of physical adhesion to the surface of the glass wire bundle; and (ii) residues or modifications of surface treatment agents that are physically adhered to the glass surface without forming chemical bonds and cannot be reduced by water cleaning. From the viewpoint of suppressing the generation of the above-mentioned (i) thermally oxidized deterioration and / or (ii) residues or modifications, X in formula (1) is preferably an organic functional group that does not form a salt with ionic compounds. Furthermore, from the viewpoint of reactivity with the matrix resin, X in formula (1) is more preferably an organic functional group having methacryloxy and / or acryloxy groups. From the viewpoint of easily obtaining the effects of the present invention, X in formula (1) is preferably not containing amines such as primary amines, secondary amines, and tertiary amines, and is preferably not containing ammonium cations such as quaternary ammonium cations.

[0042] Regarding Y in the above formula (1), in order to achieve the stabilization of the glass cloth, the alkoxy group is preferably an alkoxy group with 1 to 5 carbons (1, 2, 3, 4 or 5 carbons).

[0043] As a surface treatment agent, the silane coupling agent shown in Formula (1) can be used alone or mixed with two or more silane coupling agents different from X in Formula (1). Furthermore, as the silane coupling agent shown in Formula (1), for example, vinyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 5-hexenyltrimethoxysilane, or mixtures thereof can be used as a single component.

[0044] The molecular weight of the silane coupling agent is preferably 100-600, more preferably 150-500, and even more preferably 200-450. It is particularly preferred to use two or more silane coupling agents with different molecular weights. By using two or more silane coupling agents with different molecular weights to treat glass fiber, the density of the treatment agent on the glass surface tends to increase, thereby further enhancing the reactivity with the matrix resin.

[0045] From the viewpoint of not easily hindering reactivity with the resin, the silane coupling agent is preferably nonionic. Among nonionic silane coupling agents, those having at least one group selected from the group consisting of vinyl, methacryloxy, and acryloxy groups are preferred, and those having methacryloxy and / or acryloxy groups are particularly preferred. By ensuring reactivity with the resin, the heat resistance and reliability of the printed circuit board are easily improved.

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

[0047] <Loss on Ignition Value of Glass Cloth> From the viewpoint of seeking to reduce the dielectric loss factor of glass cloth, the loss on ignition value of glass cloth is preferably 0.010% by mass or more and not more than 0.180% by mass, more preferably 0.010% by mass or more and not more than 0.174% by mass, more preferably 0.010% by mass or more and not more than 0.150% by mass, and even more preferably 0.010% by mass or more and not more than 0.130% by mass. If the loss on ignition value is less than 0.180% by mass, it does not form chemical bonds with the glass surface but is physically attached to the glass surface. Therefore, it is easy to avoid the presence of a large amount of surface treatment agent residue and / or its modifiers on the glass cloth surface that cannot be reduced by water washing. As a result, it is easy to reduce the dielectric loss factor of glass cloth. If the loss on ignition is 0.010% by mass or more, it is easy to achieve sufficient bonding between the matrix resin and the glass cloth. Therefore, when manufacturing printed wiring boards, it is easy to ensure their heat resistance and insulation reliability.

[0048] <Yarn Width / TEX Value> The "Yarn Width / TEX" value obtained by dividing the yarn width of the glass yarn by the TEX of the glass yarn is preferably in the range of 10 to 30. This value is preferably in the range of 11 to 29, more preferably in the range of 12 to 28, further preferably in the range of 13 to 27, and even more preferably in the range of 14 to 26. Here, the "Yarn Width / TEX" value is equivalent to a parameter representing the bundle properties of the glass yarn. In the warp warping step of glass cloth, when the bundle properties of the warp are insufficient, the warp is prone to pilling, and therefore breakage is likely to occur. Therefore, if the "Yarn Width / TEX" value is 30 or less, it is easy to ensure the bundle properties of the glass yarn, and thus it is easy to prevent the glass yarn from breaking in the warp warping step. If the "Yarn Width / TEX" value is 10 or more, the fiber opening of the glass yarn in the next step becomes easier, and thus it is easy to prevent poor impregnation of the matrix resin when making the prepreg.

[0049] <Average filament diameter> The average filament diameter of the glass filament constituting the glass yarn is preferably in the range of 2.5 to 10.0 μm, preferably in the range of 2.5 to 9.0 μm, further preferably in the range of 3.5 to 8.5 μm, and further preferably in the range of 3.5 to 8.0 μm, especially in the range of 3.5 to 8.0 μm, especially 3.5 μm to 7.5 μm. If the filament diameter is more than 2.5 μm, it is easy to ensure the breaking strength of the filament and, therefore, it is easy to prevent hair feathers from the obtained glass cloth. If the filament diameter is less than 10.0 μm, it is easy to avoid the mass increase of the glass cloth, and therefore, it is easy to carry out or process.

[0050] <Jack degree> The preferably absolute value of the jelly degree of the glass yarn is in the range of 0.5 to 1.5 times / 25 mm. The better range is 0.55 to 1.45 times / 25 mm, the better is the range of 0.57 to 1.4 times / 25 mm, and the better is the range of 0.59 to 1.3 times / 25 mm, especially the range of 0.60 to 1.2 times / 25 mm. By adjusting the screw degree of the glass yarn, the kink index of the glass yarn can be controlled. The greater the absolute value of the screw degree, the easier it is to strengthen the dissolution force of the glass yarn, and therefore, it is easy to show a tendency for a larger kink index. If the absolute value of the stiffness of the glass yarn is 0.5 times / 25 mm or more, it is easy to ensure the clustering of the glass yarn, therefore, it is easy to prevent the breakage of the glass yarn in the warp yarn finishing step, and it is easy to prevent the production of hair plumes on the surface of the glass cloth. If the absolute value of the stiffness of the glass yarn is less than 1.5 times / 25 mm, it is easy to prevent the kink index of the glass yarn from becoming too large, in which case the following situation is easily avoided: During the relief of the glass yarn, it is easy to produce hair feathers on the surface of the glass cloth due to friction on the surface of the winding cylinder.

[0051] The best absolute value of the difference between the stiffness of the warp and weft yarns is in the range of 0.01 to 0.70 times / 25 mm. If this absolute value difference is 0.01 times / 25 mm or more, it is easy to improve the flatness of the glass cloth and, in the manufacture of glass cloth, it is easy to open fibers of the glass yarn. If the absolute value difference is more than 0.7 times / 25 mm, there is a tendency for the glass cloth to be significantly warped due to the different directions of the unwinding force of the warp and weft yarns (for example, the warp yarn in the z direction and the weft yarn in the s direction). Therefore, if this absolute value difference is less than 0.7 times / 25 mm, it is easy to suppress the production of hair feathers from the obtained glass cloth. The absolute value of the difference between the length of the warp and weft yarns of glass fabric is preferably in the range of 0.05 to 0.65 times / 25 mm, and further preferably in the range of 0.07 to 0.55 times / 25 mm. Furthermore, the absolute value of the difference between the length of the warp and weft yarns of the glass fabric is preferably in the range of 0.10–0.50 times / 25 mm, and further preferably in the range of 0.15–0.45 times / 25 mm.

[0052] Regarding the addition of the glass yarn, it is divided into z direction or s direction according to the direction in which the addition is carried out. In the present invention, the additive in the z direction is defined as “positive” and the adder in the s direction is defined as “negative”. For example, in this instruction manual, “1.00z of clunk” is recorded as 1.00, and “1.00s of clunk” is recorded as 1.00.

[0053] The degree of pinching of the glass yarn may, for example, be adjusted by performing a yarning step on the glass yarn (the yarn step). In the same state, by making the glass filaments clustered, it is easy to increase the strength of the glass yarn. If the length of the glass yarn is increased, it is easy to suppress the hair feathers caused by the disconnection of the glass filament, and, it is easy to suppress the breakage caused by the warping step of the glass cloth. On the other hand, the expansion of the glass yarn is easily suppressed by the addition of the glass yarn, and, in the addition part, it is easy to produce an uneven thickness of the glass cloth. Therefore, in terms of manufacturing a glass cloth of excellent quality, it is more advantageous to find a moderate degree and use a glass yarn adjusted to that degree.

[0054] <<Glass yarn curling body>> In a better state, the present invention provides a glass yarn rolling body, which is made by making the glass yarn in a state of being wound around the core material. The silicon (Si) content in the glass yarn of the glass yarn rolled body is 95.0–100 mass% by silica (SiO By using the glass yarn curling body, it is possible to provide a glass cloth that can achieve an improvement in flatness and also a reduction in the frequency of hair production.

[0055] As a more preferable element of a glass yarn constituting a glass yarn rolled body, reference may be made to a better element of a glass yarn constituting a glass fabric. For example, the glass yarn constituting a glass yarn roll preferably satisfies the ranges described in (A), (B), and (C) below: (A) x + y + z = 100 mass% (B) x ≥ 99.5 mass% (C) 0.0003 ppm ≤ y ≤ 0.50 ppm x: uranium dioxide (SiO z: Combined content of elements other than silicon, uranium, and thorium. Also, with respect to the glass yarn constituting the glass yarn roll body, preferably the absolute value of its penetration is in the range of 0.5–1.5 times / 25 mm, and again, the value of “yarn width / TEX” is preferably in the range of 10–30. Further, with respect to the better numerical range of the glass yarn constituting the glass yarn rolled body, reference can similarly be made to the better numerical range of the glass yarn constituting the glass cloth.

[0056] The core material used to wind the glass yarn may be in a state such that the core material is a winding cylinder as long as the glass yarn can be suitably relieved from the core material. However, the core material is not limited to a winding cylinder, so long as it is capable of having a function or configuration equivalent to a winding cylinder.

[0057] <<Methods for each manufacturing of glass yarn, glass yarn rolls, and glass cloth>> The present invention provides in a better state sample each method of manufacture of glass yarn, glass yarn rolls, and glass cloth. An example of a related manufacturing method is the following manufacturing method of glass yarn, the silicon (Si) content in the glass yarn is 95.0–100 mass% converted to silicon dioxide (SiO

[0058] Also, one state of the related manufacturing method is a method of manufacturing a glass yarn curling body, which includes the step of winding the above-mentioned glass yarn around a core material to constitute a rolling body.

[0059] Also, a related manufacturing method is a method of manufacturing glass cloth, which includes the step of obtaining a glass cloth using the following glass yarn, the silicon (Si) content in the glass yarn is in the range of 95.0–100 mass% by conversion of silicon dioxide (SiO

[0060] Further, one state of the related manufacturing method is a method of fabrication of glass cloth, which includes the step of obtaining a glass cloth using the following glass yarn, constituting the range of body dielectric loss factor of the glass of the glass yarn at 10 GHz below 0.001, and the kinking index of the said glass yarn in the range of 400 mm or less.

[0061] The above-mentioned manufacturing methods in the present invention may include: a step of manufacturing glass filaments by heating and stretching a glass rod (the glass filament manufacturing step); and a step of bundling a plurality of the above-mentioned glass filaments together (the glass filament bundling step).

[0062] <Making Steps of the Glass Rod> Known techniques can be utilized as a method for manufacturing the glass rod used in the production of the glass cloth of the present invention. The glass rod can be made of fused silica glass produced by electrofusion or flame melting, or a synthetic quartz rod produced by sol-gel method. In any manufacturing method, it is preferable to refine the glass rod used as raw material in order to adjust the silicon content in the glass yarn. Furthermore, in order to easily control the twist index of the glass yarn, it is preferable to refine the glass rod so that the total uranium and thorium content in the glass yarn is in the range of 0.0003 to 0.50 ppm. For example, if it is fused silica glass, it is more advantageous to use raw material powder with a lower uranium and thorium content. By using a glass rod with a total uranium and thorium content in the above range, it is easier to reduce the stretching stress during processing of the glass filaments, and consequently, it is easier to reduce the residual stress in the glass yarn, thereby making it easier to reduce the twist index of the glass yarn.

[0063] <Steps for Manufacturing Glass Filaments> In this step, glass filaments are manufactured by heating and stretching a glass rod. Known techniques can be used for further processing of the glass filaments. For example, a method for heating and stretching a glass rod can be exemplified. In one instance, a glass rod with a diameter of 1 to 50 mm can be heated and stretched in an electric furnace under an inert atmosphere at a temperature of 2000°C to manufacture glass filaments with a diameter of 3 to 10 μm. The diameter of the glass filament can be controlled by adjusting the ratio of the speed at which the glass rod is fed into the electric furnace to the speed at which the glass filament is stretched. From the viewpoint of reducing stress during the stretching of the glass rod, the temperature during heating and stretching 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] The inventors have discovered that stress generated during the heating and stretching of a glass rod remains in the resulting glass yarn, and the higher the residual stress, the greater the kink index of the glass yarn tends to be. Furthermore, the inventors have also found that to adjust the kink index of the glass yarn, reducing the residual stress in the glass yarn after stretching, for example by annealing, is more effective. For microcrystalline structures that are aligned through stretching, annealing makes them unaligned, thereby easily reducing the kink index of the glass yarn.

[0065] The annealing treatment is preferably performed between the step of heating and stretching the glass rod and the step of applying the binding agent to the glass yarn. Furthermore, from the viewpoint of easily reducing residual stress in the glass yarn, the annealing temperature is preferably in the range of 1000–1900°C, more preferably in the range of 1100–1800°C, further preferably in the range of 1200–1700°C, further preferably in the range of 1300–1650°C, and most preferably in the range of 1400–1600°C. If the annealing temperature is below 1900°C, there is a tendency to easily prevent the glass filament from breaking after heating and stretching; and if the annealing temperature is above 1100°C, it is easier to achieve the effect of reducing residual stress in the glass yarn. Furthermore, the annealing time is preferably in the range of 0.1 to 30 seconds, more preferably in the range of 0.2 to 20 seconds, even more preferably in the range of 0.3 to 5 seconds, and even more preferably in the range of 0.4 to 3 seconds.

[0066] <Bundling Step of Glass Filaments> In this step, a plurality of glass filaments are bundled together. Generally speaking, a bundle of glass filaments is called a "bundle," therefore, this step is also understood as a "method for making a glass bundle." Known techniques can be used as a method for making a glass bundle.

[0067] When manufacturing glass bundles, it is preferable to apply a bundling agent to improve the bundling properties of the glass filaments and to protect the surface of the glass filaments. Methods for applying the bundling agent include, for example, using a roller-type applicator.

[0068] Known bundlers include resin-based bundlers such as PVA, polyurethane, and epoxy resin, as well as starch-based bundlers. From the viewpoint of the migration of glass yarn during the weaving process and the ease of removing the bundler from the glass yarn, a starch-based bundler is preferred. To enhance the functionality of the glass yarn, additives such as lubricants and antistatic agents can also be added to the bundler. From the viewpoint of easily controlling the twisting of the glass yarn, when bundling the glass filaments, it is preferable to adjust the shape of the yarn path and the heating and stretching furnace to apply as uniform tension as possible 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 a range of 10 to 30, the amount of clustering agent attachment can be adjusted in the clustering step of the glass filament. Here, in terms of the view that it is easy to obtain the effect of the present invention, the sear reduction value (LOI) of the glass yarn is preferably in the range of 1.0–2.5 mass%, more preferably in the range of 1.1–2.4 mass%, and further preferably in the range of 1.2–2.3 mass%, especially in the range of 1.3–2.2 mass%. If the burning reduction value of the glass yarn is above 1.0 mass%, it is easy to ensure the clustering of the glass filament, in which case it is easy to adjust the “yarn width / TEX” value to the range of 10–30. If the scorching reduction value of the glass yarn is less than 2.5 mass%, it is easy to prevent poor degreasing and insufficient firing in the degreasing processing step of the glass yarn and in the opening step.

[0070] The method of <weaving step> may include the step of applying a prescribed addition to the glass bundle (the yarn step). For glass bundles, for example, the prescribed addition can be applied using a yarn machine. As a yarn machine or method of carrying out yarn, known devices or methods may be utilized. For example, the following method may be exemplified: the winding material of a glass beam coated with a clustering agent (e.g., referred to as a "cylinder clamp") is pulled out and winding is applied to the core material (a winding cylinder in the same state). At this point, the winding barrel is installed in the spinning machine using a fixed fixture known as the spindle. The jig yarn machine usually has a member known as a slider around the main shaft, which is capable of adjusting the degree of jig applied to the glass bundle by resorting to the speed ratio of the action of such various members.

[0071] The stitching yarn step may be used as a step for winding the glass bundle of the threaded stitch on the core material. This enables the making of glass yarn rolled bodies.

[0072] <Method of Manufacture of Glass Cloth> The method of manufacturing glass cloth includes the step of obtaining glass cloth by weaving the above glass yarn as warp and weft yarn (weaving step).

[0073] Also, the method of manufacturing glass cloth may further include the following steps before the above weaving step: using a glass yarn with a value in the range of 10 to 30 obtained by dividing the yarn width by the TEX of the glass yarn, yarning the warp yarn of the glass cloth, followed by the warp-making step of applying a bunching agent; After 3 steps and before, midway or after the above weaving steps, the step of heating and degreasing of the glass yarn to remove the clustering agent attached to the glass yarn (heating degreasing step); By having such steps, it is easy to provide a glass cloth with excellent flatness and bristle quality.

[0074] The treatment method of the glass described above (heating degreasing step, surface treatment step, and opening fiber step) may be applied to the glass yarn before weaving, again, to the glass cloth after weaving. In other words, the step of obtaining a glass cloth by weaving the glass yarn may be set before the method of treatment of that glass, midway through, or after it. Further, in the treatment method of glass, so-called “reduction,” for example, aimed at removing at least a portion of the cluster agent or silane coupling agent, may be present with a residue that is not completely removed. In the following, examples include the warping step, the weaving step, the heating and degreasing step, the surface treatment step, and the opening step in this order. However, the invention is not limited to the following examples.

[0075] <Warping step> In the warping step, a glass yarn with a Si content in the range of 95.0 to 100 mass% converted by SiO By providing a clustering agent to the glass yarn, it is easy to inhibit the production of hair feathers in the glass fabric. As a clustering agent, it is better to use those with relatively higher clustering such as starch and PVA. In order to apply the cluster agent uniformly on the glass yarn, the following method is preferable: After the glass yarn is impregnated in the cluster agent, the excess cluster agent is removed using an extrusion roller, thereafter, the cluster agent is dried.

[0076] <Weaving step> In the weaving step, the weaving yarn may be woven into the warp yarn prepared in the warp-setting step using a loom. With regard to the looms used, jet-type, sword-mast-type, shuttle-type, etc. are known, as far as the view of suppressing the hair plumes of glass cloth is concerned, it is preferable to use a jet-type loom. The better absolute value of the stiffness of the above-mentioned glass yarn in the warp yarn making and weaving steps is in the range of 0.5 to 1.5 times / 25 mm. Also, in this step, it is preferable to adjust the stiffness of the weft yarn so that the absolute value of the pitch difference between the warp and the weft yarn becomes a range of 0.01 to 0.70 times / 25 mm.

[0077] <Heating and degreasing step> In the heating and degreasing step of the glass cloth, by heating the glass yarn, it is possible to reduce arbitrarily attached to the glass yarn the clustering agent (pulp agent), its residue, and the modifications thereof, preferably able to remove it, etc. By performing the heating and degreasing step, it is possible to reduce the organic matter that may raise the dielectric loss factor and to form a surface treatment layer on the surface of the glass yarn (glass filament), which makes it easy to prepare glass cloth with excellent dielectric characteristics. As a method of carrying out heating and degreasing, known methods (heating members, heating media, heating mechanisms, heating devices, and heating parts, etc.) can be used.

[0078] As an example of the heating degreasing step, for example, there are known methods of heating a glass cloth at a temperature of 600–1600°C.

[0079] In the heat treatment step, by heating the glass cloth preform, whose softening point is above 900°C, within a temperature range of 600–1600°C, damage to the glass cloth is easily suppressed, and the dielectric loss factor of the glass cloth is easily reduced. From the viewpoint of better obtaining the effects of the present invention, the heating and degreasing temperature is preferably 700–1500°C, more preferably 800–1400°C, further preferably 900–1300°C, and even more preferably 1000–1200°C. If the heating and degreasing temperature is above 600°C, the binding agent and the like attached to the cloth can be effectively removed, thus making it easier to produce a glass cloth with excellent dielectric properties. If the heating and degreasing temperature is below 1600°C, the devitrification of the glass is easily suppressed, and as a result, the strength of the glass cloth is easily prevented from decreasing.

[0080] The heating time is preferably 30 minutes or less, more preferably 15 minutes or less, even more preferably 5 minutes or less, and especially preferably 90 seconds or less. Considering that the heating process is carried out at high temperatures, a heating time of 30 minutes or less can easily reduce damage to the glass cloth. In this case, problems such as the formation of holes in parts of the glass cloth or breakage of the glass cloth can be easily avoided during processing. From the viewpoint of effectively removing the slub, the heating time can be, for example, 1 second or more, 5 seconds or more, 10 seconds or more, or 15 seconds or more.

[0081] When degreasing glass cloth by heating within a closed system, from the viewpoint of efficient heating by the heating element, it is preferable to place the glass cloth inside the heating furnace. Furthermore, from the viewpoint of maximizing storage space and heating range efficiency, it is preferable to store the glass cloth in a wound state while heating. Moreover, from the viewpoint of improving the removal efficiency of organic matter and shortening the removal time of organic matter, it is preferable to heat the glass cloth while it is being transported within the heating furnace. The transport of the glass cloth can, for example, be performed by a combination of a winding mechanism and a take-up mechanism.

[0082] When heating and degreasing glass cloth is performed in an open system, from the viewpoint of ensuring the heated area, it is preferable to heat the glass cloth while it is being transported. The transport of the glass cloth can be carried out, for example, by a combination of a winding mechanism and a take-up mechanism.

[0083] The state of the heating deoiling step is not limited to the state described above. As another state of the heating deoiling step, for example, there is a known method that involves heating in a vacuum or a gas with a dew point of less than 15°C, under conditions where the heating amount, expressed as a heating temperature (°C) of 100°C or higher × heating time (h), is 450 (°C·h) or higher (wherein the highest heating temperature is 100 to 600°C).

[0084] <Heating Component> Examples of heating components include furnaces, electric heaters, and burners, with a gas-type single-radiant-tube burner or electric heater being preferred. Multiple different heating components can also be combined.

[0085] From the viewpoint of efficiently removing organic matter adhering to the surface of the glass cloth, a continuous heating method is preferred over a batch heating method in which the glass cloth wound around the core is heated while the glass cloth is continuously passing through the heating furnace. Even more preferred is a method that uses cleaning water with a low content of metal ions, such as reverse osmosis (RO) water or ion-exchange water, and can also continuously clean the glass cloth.

[0086] Furthermore, as a heating method, from the viewpoint of low operating costs, the component (contact component) heated to a specified temperature can be brought into contact with the glass cloth to heat the glass cloth.

[0087] The contact member may be capable of heating the glass cloth at high temperatures. For ease of handling the glass cloth, the contact member is preferably roller-shaped. Specifically, the contact member is preferably a roller that can be used in high-temperature areas, has relatively low temperature unevenness in the width direction, and heats by induction heating. When heating the glass cloth using the contact member, it is assumed that the temperature of the contact member is approximately equal to the surface temperature of the glass cloth.

[0088] In order to remove the carbides adhering to the roller during continuous heating of the glass cloth, it is preferable to use the roller described above in a manner that has a mechanism for removing the adhering foreign matter, such as a blade.

[0089] <Steam Application Method> The method for applying the above-mentioned steam to glass cloth (steam application method) may be spraying, spray diffusion, nozzle, etc. Alternatively, the gas discharged from the self-heating furnace may be reused as high-temperature steam.

[0090] The vapor used in the glass cloth may include, for example, volatile solvents, water vapor, or gases other than water vapor. From the viewpoint of suppressing toxicity to humans and from the viewpoint of easily promoting the decomposition of the binding agent used in the glass fibers, water vapor is preferred. Regarding the temperature of the high-temperature steam, the surface temperature of the glass cloth can be higher than 650°C. In this case, a method in which high-temperature steam and heated air can be supplied in any ratio, as needed. The temperature of the high-temperature steam can 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 Step> The surface treatment step can be applied to glass yarn, and also to glass cloth. In other words, the step of weaving glass yarn to obtain glass cloth can be set before, during, or after the glass treatment method of the present invention.

[0092] The step of adhering the surface treatment agent may include, for example, at least one of the following steps: a coating step of adhering the silane coupling agent to the surface of the glass using a treatment solution with a concentration of 0.1 to 0.5% by mass; and a fixation step of fixing the silane coupling agent to the surface of the glass by heating and drying. In this way, the glass can be easily and effectively surface treated.

[0093] As a method for applying the treatment solution to the glass in the coating step, it may be: (a) immersing the glass in or passing it through the treatment solution stored in a tank (hereinafter referred to as "immersion method"); (b) applying the treatment solution to the glass using a roller coater, a die coater, or a gravure coater, etc. When using the immersion method, it is preferable to select an immersion time of 0.5 seconds to 1 minute. Furthermore, when using the immersion method, a specified tension (e.g., 100 to 250 N) may be applied to the glass while the glass is passed through the treatment solution at a conveying speed of 10 to 50 m / min. Furthermore, after the treatment solution is applied to the glass, the solvent contained in the treatment solution may be heated and dried by means of hot air, electromagnetic waves, etc.

[0094] The concentration of the treatment solution is preferably 0.1 to 0.5% by mass, more preferably 0.1 to 0.45% by mass, and even more preferably 0.1 to 0.4% by mass. This facilitates better surface treatment of the glass.

[0095] In the fixation step, in order to ensure that the silane coupling agent reacts fully with the glass, the heating and drying temperature is preferably 80°C or higher, more preferably 90°C or higher. Furthermore, in order to prevent the deterioration of the organic functional groups of the silane coupling agent, the heating and drying temperature is preferably 300°C or lower, more preferably 180°C or lower.

[0096] The step of reducing silane coupling agent may include, for example, at least one of the following steps: a cleaning step of removing silane coupling agent that has not formed chemical bonds with the glass surface; a drying step of heating and drying the cleaned glass; and a fine cleaning step of reducing unwanted components that have not formed chemical bonds with the glass surface and have not been completely removed. This makes it easier to control the loss on ignition value. Furthermore, the step of reducing silane coupling agent may include, for example, a fine drying step after the fine cleaning step.

[0097] In the fine cleaning step, unwanted components that cannot be completely washed away by water in the cleaning step and have not formed chemical bonds with the glass surface can be reduced. In this fine cleaning step, for example, an organic solvent can be used as the cleaning solution. By having a fine cleaning step, even when using low-dielectric glass as described in this invention, it is easy to adjust the difference between the dielectric loss factor and the bulk dielectric loss factor of the resulting glass cloth to the range described above. As the organic solvent here, it is preferable to be an organic solvent with high hydrophobicity, and it is also preferable to be an organic solvent with high affinity for residues and modifiers of hydroxyl-containing silane coupling agents. The cleaning method can be immersion, spraying, etc., and heating or cooling can be performed as needed. In order to suppress the re-adhesion of glass dissolved in the cleaning solution, it is preferable to reduce the excess solvent in the cleaned glass by means of a squeeze roller or the like.

[0098] Organic solvents that can be used as cleaning fluid in the fine cleaning step may be used alone or in combination of several of the following solvents. Examples of highly hydrophobic organic solvents include: saturated chain aliphatic hydrocarbons such as n-pentane, isopentane, n-hexane, isohexane, n-heptane, isoheptane, n-octane, isooctane, 2,2,4-trimethylpentane (isooctane), n-nonane, isononane, n-decane, isodecanane, 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; and halogenated solvents such as chloroform, dichloromethane, and dichloroethane. Examples of organic solvents with high affinity for silane coupling agent residues or modifications include: alcohols such as methanol, ethanol, and butanol; ketones such as acetone and methyl ethyl ketone; ethers such as methyl ethyl ether and diethyl ether; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; and dimethyl sulfoxide. From the viewpoint of effectively reducing the physical adhesion of silane coupling agents to glass, aromatic hydrocarbons, alcohols, or ketones are preferred, and methanol is even more preferred. Therefore, as the cleaning fluid in the fine cleaning step, a cleaning fluid with methanol as the main component (50% or more, or 60% or more, of the cleaning fluid by mass) is preferred.

[0099] In the fine drying step, the amount of cleaning fluid used in the aforementioned fine cleaning step can be reduced. From the viewpoint that cleaning fluid can be easily reduced through drying, the cleaning fluid used in the aforementioned fine cleaning step preferably has a boiling point of 120°C or lower. Drying can be performed by heating or air drying. Furthermore, when using organic solvents as cleaning fluid, from a safety perspective, it is preferable to perform heating drying by using hot air drying with low-pressure steam or heat transfer oil as a heat source. The drying temperature is preferably above the boiling point of the cleaning fluid, and from the viewpoint of inhibiting the deterioration of the silane coupling agent, it is preferably below 180°C.

[0100] <Fiber Opening Step> Fiber opening methods in the fiber opening step can include, for example, using water spray (high-pressure water fiber opening), a vibratory cleaner, ultrasonic water, or a rolling mill to open the fiber cloth. During this fiber opening process, by reducing the tension applied to the fiber cloth, there is a tendency to further reduce air permeability. Furthermore, in order to suppress the reduction in tensile strength of the fiber cloth caused by the fiber opening process, it is preferable to implement measures such as low friction of the contact components with the weaving of the glass yarn, optimization of the sizing agent, and high adhesion. For fiber opening of fiber cloth composed of glass yarn with high glass hardness, dry ice blasting is preferred.

[0101] The above steps do not necessarily have to be performed as separate steps; multiple steps can be combined into one. For example, when a cleaning step is performed after the weaving step, the cleaning step can also serve as a fiber-opening step due to the use of a high-pressure water sprayer. The composition of the glass cloth usually remains unchanged before and after fiber opening. Furthermore, the manufacturing method of glass cloth can include any steps other than those described above. For example, a slitting step can be performed after the fiber-opening step. Also, if possible, the order of the above steps can be changed.

[0102] <Prepreg> The prepreg of the present invention comprises the above-mentioned glass cloth and a matrix resin impregnated in the above-mentioned glass cloth. Thereby, a prepreg with fewer pores can be provided.

[0103] As the base resin, a thermosetting resin or a thermoplastic resin may be used. If possible, both may be used together, and other resins may also be included.

[0104] Examples of thermosetting resins include: (a) an epoxy resin formed 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 phenolic group, an anhydride group, a hydrazide group, an isocyanate group, a cyanidin group, and a hydroxyl group that reacts with the epoxy group; (b) a free radical polymeric curing resin formed by curing a compound having at least one group selected from the group consisting of an allyl group, amethacrylyl group, and an acrylyl group; (c) a maleimide trimethylolpropene resin formed by reacting a compound having a cyanidin group with a compound having a maleimide group; and (d) a thermosetting polyimide resin formed by reacting a maleimide compound with an amine compound. (e) Benzo[a] resins, etc., formed by crosslinking and curing compounds containing benzo[a] rings through heating polymerization. Furthermore, in obtaining (a) epoxy resin, the compound can react without adding a catalyst, or a catalyst with reaction catalytic ability, such as imidazole compounds, tertiary amine compounds, urea compounds, and phosphorus compounds, can be added to react the compound. Also, in obtaining (b) free radical polymerization type cured resin, a thermally decomposable catalyst or a photodecomposable catalyst can be used as a reaction initiator.

[0105] Examples of thermoplastic resins include polyphenylene ether, modified polyphenylene ether, polyphenylene sulfide, polyurethane, polyetherurethane, polyarylate, aromatic polyamide, polyetheretherketone, thermoplastic polyimide, insoluble polyimide, polyamide-imide, and fluororesins. As an insulating material for printed circuit boards used in high-speed communications, polyphenylene ether or modified polyphenylene ether with sufficient free radical reactivity is preferred.

[0106] When the matrix resin used in the printed wiring board for high-speed communication has vinyl or methacrylic groups, the silane coupling agent with relatively high hydrophobicity and functional groups such as methacrylic groups that participate in free radical reactions has good compatibility with the matrix resin.

[0107] As described above, thermosetting resins and thermoplastic resins can be used in combination. Furthermore, the prepreg may contain inorganic fillers. The inorganic fillers are preferably used in combination with thermosetting resins, and examples include aluminum hydroxide, zirconium oxide, calcium carbonate, alumina, mica, aluminum carbonate, magnesium silicate, aluminum silicate, silicon oxide, talc, short glass fibers, aluminum borate, and silicon carbide. The inorganic fillers can be used alone or in combination of two or more.

[0108] <Printed Wiring Board> The printed wiring board of the present invention includes the above-described prepreg. This provides a printed wiring board with excellent insulation reliability.

[0109] <Integrated Circuits and Electronic Devices> Furthermore, integrated circuits and electronic devices comprising the above-described printed wiring board are also an embodiment of the present invention. Integrated circuits and electronic devices obtained using the printed wiring board of the present invention exhibit excellent characteristics. [Example]

[0110] Hereinafter, examples and comparative examples will be given to illustrate embodiments of the present invention. However, the present invention is not limited to the following examples. Regarding the examples and comparative examples, various manufacturing, measurement, and evaluation processes are performed by the following methods. Furthermore, unless otherwise specified, various manufacturing, measurement, and evaluation processes are performed at room temperature (25°C) and atmospheric pressure.

[0111] <<Determination>><Thickness of Glass Cloth (μm)> The thickness of the glass cloth is determined according to JIS R 3420 7.10. Specifically, using a micrometer, the spindle is rotated quietly until it is parallel to the measurement surface of the sample and gently contacts it. Then, the scale is read after the ratchet clicks three times. Furthermore, JIS R 3420 7.10 specifies the general test method for cloth products such as glass cloth.

[0112] <Twist Index of Glass Wool (mm)> The twist index of the glass wool was determined according to JIS L 1095, 9.17. Specifically, firstly, with the initial load described in Method A of JIS L 1095, 9.17.1, applied to the glass wool (sample), the glass wool was stretched taut in a straight line relative to the clamps, and then a load of 1.1 × 10⁻⁶ N / tex was applied to its center. At a speed of 0.5 m / min, one clamp B was brought close to the other clamp A to relax the sample. The position of clamp B at the load point was read from the scale. The number of tests was set to 30, and the average value was calculated to determine the twist index.

[0113] <TEX of Glass Wool (g / 1000 m)> The TEX of the glass wool was determined according to JIS R3420 2012. Specifically, a sample of 1000 m of glass wool was subjected to a heat degreasing treatment for 30 minutes in a muffle furnace set at 625±20℃ to remove the binding agent adhering to the glass wool. At this time, it was determined whether the binding agent had been removed by checking whether the weight reduction of the glass wool before and after the heat degreasing was less than 0.1% by mass. That is, if the weight reduction of the glass wool before and after the heat degreasing was less than 0.1% by mass, it was determined that the binding agent had been removed. The TEX of the glass wool was determined by measuring the weight of the 1000 m of glass wool that had undergone the heat degreasing treatment.

[0114] <Content of each element contained in glass yarn> The contents of silicon, uranium and thorium that make up the glass yarn are determined by the absolute calibration curve method using an ICP quality analysis device.

[0115] <Silicone content (mass %)> In order to reduce impurities (such as sizing agents) adhering to the glass yarn or its raw materials, the constant solution is adjusted by the following method. That is, the glass yarn (sample) is weighed, then hydrolyzed with sodium hydroxide, and then dissolved with dilute nitric acid, thereby adjusting the constant solution.

[0116] The silicon content of the obtained solution was determined using an ICP luminescence spectrophotometer (PS3520VDDII manufactured by Hitachi High-Tech Science Co., Ltd.), and then converted into oxide values ​​to determine the silicon content in the sample.

[0117] <Uranium and Thorium Content (ppm)> The weighed glass gauze (sample) was heated and washed with aqua regia, and then washed with ultrapure water. The sample was decomposed using nitric acid, hydrofluoric acid, and sulfuric acid, and then heated and concentrated until sulfuric acid fumes were produced. The volume was then adjusted with dilute nitric acid.

[0118] The obtained volumetric solution was analyzed using an ICP mass analyzer (SPQ9400 manufactured by SII NanoTechnology Inc.) to determine the uranium and thorium content in the sample.

[0119] <Content of Other Components (mass %)> Subtract the contents of silicon, uranium, and thorium from 100% by mass to determine the content of other components (elements other than silicon, uranium, and thorium) in the glass fiber (sample). Other components are indicated as "impurities" in the table below. Here, the unit "ppm" used to express the content of uranium and thorium is converted to 1 ppm = 0.0001% by mass.

[0120] <The stiffness of the glass yarn, and its absolute value difference (secondary / 25 mm)> The determination of the glass yarn (secondary / 25 mm) was obtained according to JIS R3420. In determining the degree, in order to be able to accurately determine the degree of the glass yarn in the glass cloth, the glass yarn (warp or weft) is pulled from the glass cloth, and the determination of the glass yarn (the warp or the weft) is subsequently performed. Regarding the obtained values, the additive in the z direction is considered positive and the adder in the s direction is considered negative. For example, the addition of 1.00 z (the addition of 1.00 (second / 25 mm) towards the z direction) is considered as +1.00, and, the addition of 1.00 s (the addition of 1.00 (second / 25 mm) towards the s direction) is considered as -1.00. Thereafter, the absolute value difference (seconds / 25 mm) of the length of the warp and the weft yarn is calculated by the following formula: The absolute value difference of the yarn degree = |

[0121] < Yarn width of glass yarn (μm)> On one side, the glass yarn was carried at a speed of 1 m / min, and on the other hand, a penetrating size determiner (HIGH ACCURACY CMOS MICROMETER LS-9006MR / manufactured by Keenz Corporation) with LED projection was used to determine the yarn width of 50 m glass yarn. Based on the obtained data on the width of the yarn with a length of 50 m, the average value of the ratio, and the width of the yarn, occupied below the specific yarn width was calculated. The yarn width determination utilizing a penetrating size meter by LED projection was performed under the condition that a determination value of 1934 points was obtained every 1 m. The average value of the glass yarn width was calculated by deleting the determination value due to the misalignment of focus of the LED equal (displayed -9999 value). Furthermore, the computation was performed by omitting the assays that produced errors as appropriate. Furthermore, regarding the tension acting on the glass yarn when moving the glass yarn, it was 0.12–0.18 N when determined using a tensiometer (Conrol instruments ETPB-100-C0585, a control equipment manufactured by SCHMIDT Company).

[0122] < Yarn width / TEX (μm / (g / 1000 m))> The value of the yarn width / TEX is obtained by dividing the above obtained yarn width by the above obtained TEX.

[0123] <Bulk Dielectric Loss Factor at 10 GHz> According to IEC 62562, the bulk dielectric loss factor of each glass rod (body) used as the raw material for each glass yarn is determined at 10 GHz. Specifically, glass plate samples of less than 300 μm, taken to the size required for measurement using a split cylindrical resonator, are stored in a constant temperature and humidity oven at 23°C and 50%RH for 8 hours. Subsequently, the dielectric properties of the stored samples are measured using a split cylindrical resonator (manufactured by EM Labs) and an impedance analyzer (manufactured by Agilent Technologies). Five measurements are performed on each sample, and the average value is calculated. Furthermore, IEC 62562 mainly specifies the method for measuring the dielectric properties of precision ceramic materials used in microwave circuits in the microwave band.

[0124] <Number of filaments and filament diameter (μm) of warp and weft yarns> When calculating the average fiber opening, the number of filaments and filament diameter of the warp and weft yarns are determined by observing a cross-sectional image of the glass yarn. Specifically, a cross-sectional image of the glass yarn (or weft yarn) is obtained, and the number of filaments and filament diameter of the warp (or weft yarn) are measured in the cross-sectional image. Similarly, an image of the glass yarn is obtained, the number of filaments is repeatedly measured, and the average of the five measurements is taken as the number of filaments and filament diameter of the warp (or weft yarn).

[0125] <Warp Width and Weft Width> When calculating the average fiber opening, the warp width and weft width are determined by the following method. First, five glass cloth samples with dimensions of 70 mm in the warp direction and 70 mm in the weft direction are cut from the glass cloth. The cut samples are observed vertically using a macroscope at 100x magnification. The width of 250 warp (or weft) yarns is randomly measured for each sample, and the average value of the obtained 250 warp (or weft) yarn widths is calculated. This average value is taken as the warp width (or weft width).

[0126] <Warp and weft yarn opening degree (%), and average opening degree of glass cloth (%)> The opening degree of the warp yarn of the glass cloth is calculated by the following formula: Warp yarn opening degree (%) = [warp width (μm) / {number of warp filaments × diameter of warp filaments (μm)}] × 100 The opening degree of the weft yarn of the glass cloth is calculated by the following formula: Weft yarn opening degree (%) = [weft width (μm) / {number of weft filaments × diameter of weft filaments (μm)}] × 100

[0127] Using the calculated warp yarn opening degree (%) and weft yarn opening degree (%), calculate the average opening degree using the following formula: Average opening degree (%) = {warp yarn opening degree (%) + weft yarn opening degree (%)} / 2

[0128] <Feather Quality> The glass cloth obtained in the examples and comparative examples was subjected to a tension of 100 N / 1000 mm using a roll-to-roll inspection table. While irradiating with a halogen lamp, the number of feathers was visually determined, especially the number of feathers with protrusions of 1 mm or more. The number of feathers per 1 m² was considered the feather frequency, and the feather quality was evaluated using this frequency according to the following criteria. (Measurement Criteria) Feather Quality A: Feather frequency of 10 feathers / m² or less. Feather Quality B: Feather frequency of 11 to 20 feathers / m². Feather Quality C: Feather frequency of 21 feathers / m² or more.

[0129] <Warpage of Glass Cloth> The glass cloth obtained in the Examples and Comparative Examples was cut into 200 mm × 200 mm pieces to obtain samples. The samples were placed on a flat measuring stage, and the warpage of the glass cloth was measured.

[0130] Figures 1(a) to (b) are schematic diagrams illustrating the method for measuring the warpage of glass cloth. Figure 1(a) schematically shows a top view of the glass cloth and the stage from above, while Figure 1(b) schematically shows a cross-sectional view when observing the left end portion of the glass cloth in Figure 1(a) (the portion enclosed by the dashed line A) as the front-to-depth section. In Figures 1(a) to (b), the x, y, and z directions correspond respectively.

[0131] As shown in the figure, sample 2 of glass cloth is placed on a flat measuring stage 1. Sample 2 is bent upwards from the left end of the measuring stage 1, thereby rising a height T1. At this time, the height T1 is regarded as the warping amount of the glass cloth at the left end. Similarly, as shown in examples (a) to (b) in Figure 1, the height T2 of the glass cloth at the upper end is regarded as the warping amount of the glass cloth at the upper end, the height T3 of the glass cloth at the right end is regarded as the warping amount of the glass cloth at the right end, and the height T4 of the glass cloth at the lower end is regarded as the warping amount of the glass cloth at the lower end. Among the warping amounts at the four ends of the glass cloth, the maximum warping amount Tmax is represented as "warping amount" in the table below.

[0132] Figures 2(a) to (b) are schematic diagrams used to further illustrate the method for measuring warpage. Figures 2(a) to (b) correspond to the cross-section of the portion enclosed by the dashed line A in Figure 1(a). In Figure 2(a), the sample curls at the left end. In this case, the height Ta of the apex of the curl is considered as the warpage of the glass cloth at the left end. Also, in Figure 2(b), the sample bends into an arc shape at the left end. In this case, the height Tb of the apex of the arc is also considered as the warpage of the glass cloth at the left end.

[0133] <Preparation of Prepreg Samples> 45 parts by weight of polyphenylene ether (manufactured by SABIC, Noryl SA9000), 10 parts by weight of triallyl isocyanate, 45 parts by weight of toluene, and 0.6 parts by weight of 1,3-bis(tributylisopropylbenzene) were added to a stainless steel container and stirred at room temperature for 1 hour to prepare a varnish. Glass cloths obtained in the examples and comparative examples were impregnated with the prepared varnish and dried at 115°C for 1 minute. This yielded a sample of the prepreg.

[0134] <Maloperation Performance Test> Two copper foils with a thickness of 18 μm were used to clamp the two sides of the prepreg obtained above. The substrate was then hardened by heating and pressurizing at 200°C and 40 kg / cm² for 2 hours. Subsequently, a copper wiring pattern with an L / S (line to gap) of 10 μm was fabricated on the substrate, and 30 DRAMs were mounted in connection with this wiring pattern. The substrate with the DRAMs was continuously driven for 1000 hours at a temperature of 150°C and a frequency of 10 GHz. Based on this, the maloperation performance caused by uranium and thorium contained in the glass fiber was evaluated. (Evaluation Criteria) A: 0 DRAM maloperations. B: 1-2 DRAM maloperations. C: 3-4 DRAM maloperations. D: 5-6 DRAM maloperations. E: 7-8 DRAM maloperations. F: 9 DRAM maloperations. G: The number of DRAM malfunctions is 10 or more.

[0135] <<Examples and Comparative Examples>> <Manufacture of Glass Yarn 1 and its rolls> A quartz glass rod (diameter = 1 mm) with a silicon content = 99.92 mass% and a combined content of uranium and titanium = 0.103 ppm was used for the fabrication of glass yarn. Quartz glass rods were fed into a heating furnace filled with sufficient amount of argon and set at 1970°C, followed by heating extension, thereby producing glass yarns with diameter = 5.0 μm and number of filament roots = 50. Furthermore, the treatment of reducing the residual stress present in the glass filament was performed (annealing treatment) by heating each glass filament to pass through a heating furnace set at a temperature of 1500°C within 1 second. The annealed-treated glass filament was yarned, followed by a dressing imparting the clustering agent using starch as the main agent, which was subsequently rolled to a cylinder clamp, thereby obtaining a glass filament bundle (glass bundle). Using a yarn machine, the obtained filament bundles were pinned at a spacing of 0.8 times / 25 mm in the z direction, followed by winding to the winding cylinder, thereby obtaining glass yarn 1 and its curling body, respectively

[0136] <Manufacture of glass yarn 2 and its rolls> Except for the use of quartz glass rods (diameter = 1 mm) with silicon content = 99.98 mass% and combined content of uranium and titanium = 0.0036 ppm, glass yarn 2 and its rolls were obtained separately by the same method as glass yarn 1 .

[0137] <Manufacture of glass yarn 3 and its rolls> Except for the use of quartz glass rods (diameter = 1 mm) with silicon content = 99.90 mass% and combined content of uranium and titanium = 0.204 ppm, glass yarn 3 and its roll body were obtained by the same method as glass yarn 1 , respectively.

[0138] <Manufacture of glass yarn 4 and its rolls> Except for the use of quartz glass rods (diameter = 1 mm) with silicon content = 99.85 mass% and combined content of uranium and titanium = 0.389 ppm, glass yarn 4 and its roll body were obtained by the same method as glass yarn 1 , respectively.

[0139] <Manufacture of glass yarn 5 and its coiled body> In addition to the heating extension of the glass rod in such a manner that the number of filament roots becomes 200, the glass yarn 5 and its coiled body are respectively obtained by the same method as in Example 1 .

[0140] <Manufacture of glass yarn 6 and its coiled body> In addition to heating extension of the glass rod in such a manner that the number of filament roots becomes 200, the glass yarn 6 and its coiled body were obtained, respectively, by the same method as in Example 2 .

[0141] <Manufacture of glass yarn 7 and its coiled body> Glass yarn 7 and its coiled body were respectively obtained by the same method as in Example 1, except for splicing at a spacing of 0.4 times / 25 mm in the z direction.

[0142] <Manufacture of glass yarn 8 and its rolls> In addition to setting the temperature for annealing the glass filament to 1200°C, glass yarn 8 and its rolls were obtained, respectively, by the same method as in Example 1 .

[0143] <Manufacture of glass yarn 9 and its coiled body> In addition to setting the temperature for annealing the glass filament to 1200°C, glass yarn 9 and its coiled body were respectively obtained by the same method as in Example 2 .

[0144] <Manufacture of glass yarn 10 and its rolls> Glass yarn 10 and its rolls were obtained separately by the same method as in Example 1, except for annealing treatment of the glass filament.

[0145] <Manufacture of glass yarn 11 and its rolls> Except for the use of quartz glass rods (diameter = 1 mm) with silicon content = 99.70 mass% and combined content of uranium and titanium = 0.561 ppm, glass yarn 11 and its rolls were obtained separately by the same method as glass yarn 1 .

[0146] <Manufacture of glass yarn 12> The glass is processed by the same method as in Example 1, except that the temperature for annealing the glass filament is set to 2000°C. However, in the annealing treatment a number of glass filaments were broken, so the glass yarn and its curling body could not be obtained.

[0147] <Manufacture of glass yarn 13 and its rolls> Except for the use of quartz glass rods (diameter = 1 mm) with silicon content = 99.99 mass% and combined content of uranium and titanium = 0.0017 ppm, glass yarn 13 and its rolls were obtained separately by the same method as glass yarn 1 .

[0148] <Manufacture of glass yarn 14 and its rolls> Except for the use of quartz glass rods (diameter = 1 mm) with silicon content = 99.91 mass% and combined content of uranium and titanium = 0.09 ppm, glass yarn 14 and its roll body were obtained by the same method as glass yarn 1 , respectively.

[0149] <Manufacture of glass yarn 15 and its rolls> Except for the use of quartz glass rods (diameter = 1 mm) with silicon content = 99.99 mass% and combined content of uranium and titanium = 0.0006 ppm, glass yarn 15 and its rolls were obtained separately by the same method as glass yarn 1 .

[0150] <Manufacture of glass yarn 16 and its rolls> Except for the use of quartz glass rods (diameter = 1 mm) with silicon content = 99.99 mass% and combined content of uranium and titanium = 0.0010 ppm, glass yarn 16 and its rolls were obtained separately by the same method as glass yarn 1 .

[0151] <Manufacture of glass yarn 17 and its rolls> Except for the use of quartz glass rods (diameter = 1 mm) with silicon content = 99.98 mass% and combined content of uranium and titanium = 0.0022 ppm, glass yarn 17 and its rolls were obtained separately by the same method as glass yarn 1 .

[0152] <Manufacture of glass yarn 18 and its rolls> Except for the use of quartz glass rods (diameter = 1 mm) with silicon content = 99.93 mass% and combined content of uranium and titanium = 0.03 ppm, glass yarn 18 and its roll body were obtained by the same method as glass yarn 1 , respectively.

[0153] <Example 1> Using glass yarn 1 as warp and weft yarn. During the warping step of warping yarn, the lining of the warp yarn was carried out at a linear speed = 60 m / min, and subsequently, the warp shaft of the shuttle loom that had undergone two pulping treatments using PVA buncher was prepared. Subsequently, using an air jet chamber, 2000 m of glass fabric embryo fabric with plain weave construction was woven with a braiding density of 66 strands / 25 mm warp yarn, 68 strands / 25 mm weft yarn, and a cloth width of 1300 mm. Furthermore, in the weaving step, the main nozzle pressure and the auxiliary nozzle angle of the loom were adjusted in such a way that the pin of the weft yarn became 0.6 times / 25 mm in the z direction, since it was able to adjust the pin of the weft yarn according to the conditions of the loom.

[0154] The obtained glass cloth embryo fabric was washed using ion exchange water, and thereafter, allowed to dry. Thereby, alkali metal ions etc. attached to the cloth surface are removed. Thereafter, degreasing by heating at 1000°C for 15 seconds (heating degreasing step). Subsequently, the treatment solution obtained by adjusting so that 3-methacrylate oxypropyltrimethoxysilane (silane coupling A);Z6030 (made by Dow Toray Corporation) 0.3 mass% was dispersed in pure water adjusted to pH = 3 using acetic acid. The cloth was impregnated in the treatment solution at a linear tension of 100 N and a linear speed of 15 m / min (surface treatment worker step). After squeezing off the treatment solution on the cloth, it was heated at 130°C for 60 seconds and dried, thereby, setting the silane coupling agent (setting step).

[0155] The dried fabric was irradiated with ultrasound at a frequency of 25 kHz and an output of 0.50 W / cm² in water. Subsequently, excess silane coupling agent physically adhering to the fabric was reduced using a columnar stream of water sprayed at 1.4 MPa, and the fabric was subjected to a fiber-opening treatment (fiber-opening step). The fabric was then dried at 130°C for 1 minute (drying step). The glass cloth of Example 1 was obtained through the above operations.

[0156] <Examples 2-16 and Comparative Example 1> Except for the changes to the items listed in the table below, the glass cloth was obtained in the same way as in Example 1.

[0157] The manufacturing conditions and evaluation results for the embodiments and comparative examples are shown in the table below. Furthermore, the glass cloth of the embodiments can be used to manufacture prepregs, printed circuit boards, integrated circuits, and electronic devices by conventional methods.

[0158] [Table 1] Table 1. Glass yarn 1 Glass yarn 2 Glass yarn 3 Glass yarn 4 Glass yarn 5 Glass yarn 6 Glass yarn 7 Silicon content wt% 99.92 99.98 99.90 99.85 99.92 99.98 99.92 Uranium content ppm 0.062 0.0031 0.121 0.287 0.062 0.0031 0.062 Thorium content ppm 0.041 0.0005 0.083 0.102 0.041 0.0005 0.041 Total uranium + thorium content ppm 0.103 0.0036 0.204 0.389 0.103 0.0036 0.103 Impurity content wt% 0.08 0.02 0.10 0.15 0.08 0.02 0.08 Volume dielectric loss factor @ 10 GHz - 0.0002 0.0002 0.0002 0.0002 0.0002 0.0002 0.0002 Kink index mm 200 [[ID=IMPORTANT]]230 130 120 190 220 190 Twist turns / 25 mm 0.8 0.8<​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ 105 105 150 150 140 Yarn width / TEX μm / (g / 1000 m) twenty four twenty four twenty four twenty four 17 17 32 Loss on ignition wt% 1.6 1.6 1.6 1.6 1.2 1.2 1.6 filament diameter μm 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Number of filaments - 100 100 100 100 200 200 100

[0159] [Table 2] Table 2. Glass yarn 8 Glass yarn 9 Glass yarn 10 Glass yarn 11 Glass yarn 12 Glass yarn 13 Glass yarn 14 Silicon content wt% 99.92 99.98 99.92 99.70 - 99.99 99.91 Uranium content ppm 0.062 0.0031 0.062 0.374 - 0.0010 0.07 Thorium content ppm 0.041 0.0005 0.041 0.187 - 0.0007 0.02 Total uranium + thorium content ppm 0.103 0.0036 0.103 0.561 - 0.0017 0.09 Impurity content wt% 0.08 0.02 0.08 0.300 - 0.01 0.09 Dielectric loss factor @ 10 GHz - 0.0002 0.0002 0.0002 0.0002 - 0.0002 0.0002 Kink index mm 220 250 500 110 - 304 ​​​​​ 0.8 0.8 0.8 0.8 - 0.8 0.8 TEX g / 1000 m 4.3 4.3 4.3 4.3 - 4.3 4.3 Yarn width μm 105 105 105 105 - 105 105 Yarn width / TEX μm / (g / 1000 m) twenty four twenty four twenty four twenty four - twenty four twenty four Loss on ignition wt% 1.6 1.6 1.6 1.6 - 1.6 1.6 filament diameter μm 5.0 5.0 5.0 5.0 - 5.0 5.0 Number of filaments - 100 100 100 100 - 100 100

[0160] [Table 3] Table 3. Glass yarn 15 Glass yarn 16 Glass yarn 17 Glass yarn 18 Silicon content wt% 99.99 99.99 99.98 99.93 Uranium content ppm 0.0005 0.0007 0.0020 0.02 Thorium content ppm 0.0001 0.0003 0.0002 0.01 Total uranium + thorium content ppm 0.0006 0.0010 0.0022 0.03 Impurity content wt% 0.01 0.01 0.02 0.070 Volume dielectric loss factor @ 10 GHz - 0.0002 0.0002 0.0002 0.0002 Kink index mm 340 320 290 210 Twist density turns / 25 mm 0.8 0.8 0.8 0.8 TEX g / 1000 m 4.3 4.3 4.3 4.3 Yarn width μm 105 105 105 105 Yarn width / TEX μm / (g / 1000 m) twenty four twenty four twenty four twenty four Loss on ignition wt% 1.6 1.6 1.6 1.6 filament diameter μm 5.0 5.0 5.0 5.0 Number of filaments - 100 100 100 100

[0161] [Table 4] Table 4. Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 warp and weft yarns - Glass yarn 1 Glass yarn 2 Glass yarn 3 Glass yarn 4 Glass yarn 5 Glass yarn 6 Density Root / 25mm 66 66 66 66 54 54 Latitude density Root / 25 mm 68 68 68 68 54 54 The thickness of the glass cloth μm 25 25 25 25 40 40 Fuck menstrual yarn times / 25 mm 0.8 0.8 0.8 0.8 0.8 0.8 Fuck the weft times / 25 mm 0.6 0.6 0.6 0.6 0.6 0.6 The absolute value difference of the fucking degree times / 25 mm 0.2 0.2 0.2 0.2 0.2 0.2 Open fiber degree warp yarn % 65 65 65 65 45 45 Open Fiber Weft % 83 83 83 83 61 61 Average open fiber % 74 74 74 74 53 53 Warpage (Tmax) mm 2.5 3.0 1.0 1.0 2.0 3.5 Feather quality - A A A A A A Malfunction Performance Evaluation - D B D E D B

[0162] [Table 5] Table 5. Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 warp and weft yarns - Glass yarn 7 Glass yarn 8 Glass yarn 9 Glass yarn 11 Glass yarn 13 Glass yarn 14 Density Root / 25mm 66 66 66 66 66 66 Latitude density Root / 25mm 68 68 68 68 68 68 The thickness of the glass cloth μm 25 25 25 25 25 25 Fuck menstrual yarn times / 25 mm 0.4 0.8 0.8 0.8 0.8 0.8 Fuck the weft times / 25 mm 0.3 0.6 0.6 0.6 0.6 0.6 The absolute value difference of the fucking degree times / 25 mm 0.1 0.2 0.2 0.2 0.2 0.2 Open fiber degree warp yarn % 73 65 65 65 65 65 Open Fiber Weft % 92 83 83 83 83 83 Average open fiber % 83 74 74 74 74 74 Amount of Warping (Tmax) mm 2.0 3.0 3.5 1.0 4.0 1.5 Hairiness quality - B A A A A A Malfunction performance evaluation - D D B G B D

[0163] [Table 6] Table 6. Example 13 Example 14 Example 15 Example 16 Comparative Example 1 Warp and weft yarns - Glass yarn 15 Glass yarn 16 Glass yarn 17 Glass yarn 18 Glass yarn 10 Warp density Per 25 mm 66 66 66 66 66 Weft density Per 25 mm 68 68 68 68 68 Thickness of glass cloth μm 25 25 25 ]>25 25<s Twist of warp yarn Per 25 mm 0.8 0.8 0.8 0.8 0.8 Twist of weft yarn times / 25 mm 0.6 0.6 0.6 0.6 0.6 The absolute value difference of the fucking degree times / 25 mm 0.2 0.2 0.2 0.2 0.2 Open fiber degree warp yarn % 65 65 65 65 65 Open Fiber Weft % 83 83 83 83 83 Average open fiber % 74 74 74 74 74 Amount of Warping (Tmax) mm 4.0 4.0 4.0 3.0 6.5 Fleece quality —— A A A A C Mismotion performance evaluation —— A A B C D

[0164] It is confirmed from the above table that, in accordance with embodiments, a glass cloth capable of providing an improvement in flatness and a reduction in the frequency of generation of bristles can also be achieved. Furthermore, it is also confirmed from the above table that the combined control of the contents of uranium and titanium in the glass yarn is beneficial for the <misaction performance test> evaluation. [Industrial Availability]

[0165] The present invention can be suitably applied in the fields related to the manufacture of glass yarn, glass cloth, prepreg and printed wiring board, and glass cloth manufacturing methods. [Simplified Explanation of the Diagram]

[0013] Figures 1(a) to (b) are schematic diagrams illustrating the method for measuring warp in this invention. Figures 2(a) to (b) are schematic diagrams illustrating the method for measuring warp in this invention.

Claims

1. A glass fabric containing glass yarn, the silicon (Si) content in the above-mentioned glass yarn is 95.0~100 mass% converted by silicon dioxide (SiO2), the kink index of the above-mentioned glass yarn is less than 400 mm, and the above-mentioned glass yarn contains glass yarn that satisfies the range described in the following formulas (A), (B), and (C) y ≥ 9% mass, (A (C) 0.0003 ppm≤y≤0.50 ppm x: Silicon content in conversion of silicon dioxide (SiO2) y: Total content of uranium and titanium z: Total content of elements other than silicon, uranium, and thorium.

2. A glass fabric which contains glass yarn, the body dielectric loss factor of the glass constituting the glass yarn at 10 GHz is in the range of 0.001 or less, the kinking index of the glass yarn is 400 mm or less, and the glass yarn contains the glass yarn that satisfies the ranges described in equations (A), (B), and (C) below, (A) (C) 0.0003 ppm≤y≤0.50 ppm x: Silicon content in conversion of silicon dioxide (SiO2) y: Total content of uranium and titanium z: Total content of elements other than silicon, uranium, and thorium.

3. If the glass cloth of claim 1 or 2, wherein the kinking index of the said glass yarn is 70 mm or more.

4. As in the glass cloth of claim 1 or 2, wherein the range of the above x is in the range of 99.6% by mass.

5. Such as the glass cloth of claim 1 or 2, wherein the range of the above x is in the range of 99.9% by mass.

6. The glass cloth of claim 1 or 2, wherein the said glass yarn is treated with a surface treatment comprising a silane coupling agent.

7. The glass cloth of claim 6, wherein the said surface treatment agent comprises the said silane coupling agent shown in the following formula (1): X(R)3-nSiYn・・・(1) (In formula (1) , X is an organic functional group of at least one having an amine group, and an unsaturated double bond with radical reactivity, Y is each independently an alkoxy group, n is an integer above 1 and below 3, and R is each independently a group selected from the group composed of methyl, ethyl, and phenyl group).

8. As in the glass cloth of claim 7, wherein X in formula (1) above is an organic functional group that has not formed a salt with an ionic compound.

9. As in the glass cloth of claim 7, wherein X in formula (1) above does not comprise an amine and / or ammonium cation.

10. As in the glass cloth of claim 7, wherein X in formula (1) above is an organic functional group having a methacrylate oxy group and / or an acrylamide oxy group.

11. Such as the glass cloth of claim 1 or 2, wherein the absolute value of the degree of jerk of the said glass yarn is in the range of 0.5 to 1.5 times / 25 mm.

12. If the glass cloth of claim 1 or 2, wherein the said glass cloth has the said glass yarn as warp and weft yarn and the absolute value of the difference between the degree of the said warp yarn and the said weft yarn is in the range of 0.01 to 0.70 times / 25 mm.

13. The glass cloth of claim 1 or 2, wherein the thickness of the said glass cloth is 60 μm or less.

14. As in the glass cloth of claim 1 or 2, which is used to print the patch panel.

15. A prepreg containing a glass cloth as in claim 1 or 2, and a thermosetting resin.

16. A printed patch panel comprising a prepreg as in claim 15 .

17. An integrated circuit comprising a printed distribution board as in claim 16 .

18. An electronic machine comprising a printed patch panel as in claim 16 .

19. A method of manufacturing glass cloth comprising the step of obtaining a glass cloth using the following glass yarn, the silicon (Si) content in the range of 95.0 to 100 mass% converted to silicon dioxide (SiO2), the kinking index of the above glass yarn is less than 400 mm, and the method of manufacturing the glass cloth includes the use of the glass gauze obtained in the above steps (A), (C), and (A) x+y+z=100 mass% (B) x≥99.5 mass% (C) 0.0003 ppm≤y≤0.50 ppm 20. A method of fabrication of glass cloth comprising the step of obtaining a glass cloth using the following glass yarn constituting the body dielectric loss factor of the glass at 10 GHz in the range of 0.001 or less, the kinking index of the glass yarn in the range of 400 mm or less, and the manufacturing method of the glass cloth comprising the use of the glass cloth as described in the range described in (A), (B), and (C) described above: (A) x+y+z=100 mass% (B) x≥99.5 mass% (C) 0.0003 ppm≤y≤0.50 ppm 21. If the method of manufacture of the glass cloth of claim 19 or 20, wherein the kinking index of the said glass yarn is 70 mm or more.

22. If the method of manufacture of the glass cloth of claim 19 or 20, which includes the step of warping the said glass yarn being used as the warp yarn (warp yarn warping step), and the step of weaving using the said glass yarn (weaving step), in the said warp yarn warping step and / or the said weaving step, the absolute value of the stiffness of the said glass yarn is adjusted to a range of 0.5 to 1.5 times.

23. If the method of manufacture of the glass cloth of claim 22, wherein the said glass cloth has the said glass yarn as warp and weft yarn, the method of manufacture of the said glass cloth includes the step of adjusting the stiffness of the said weft yarn so that the absolute value of the difference between the said warp and the said weft yarn and the said weft yarn makes the absolute value in the range of 0.01 to 0.70 times / 25 mm.

24. If the method of manufacturing the glass cloth of claim 22 or 23, it is to perform the warp yarn-making steps described above and / or the weaving steps described above using the glass yarn in which the yarn width of the above-mentioned glass yarn is divided by the value obtained by TEX in the range of 10 to 30.

25. A glass yarn rolled body, which has a core material and a glass yarn wound on the said core material, the silicon (Si) content in the said glass yarn is 95.0~100 mass% converted by silica (SiO2), the kink index of the above glass yarn is less than 400 mm, and the above glass yarn satisfies the range of (A), (B), and (C) x0% as described in (A), (B), and (C) (B) x≥99.5 mass% (C) 0.0003 ppm≤y≤0.50 ppm x: Silicon content at conversion of silicon dioxide (SiO2) y: Combined contents of uranium and titanium z: Combined content of elements other than silicon, uranium, and thorium.

26. If the glass yarn rolled body of claim 25, wherein the kinking index of the said glass yarn is 70 mm or more.

27. In the case of the glass yarn roll body of claim 25 or 26, wherein the absolute value of the stiffness of the said glass yarn is in the range of 0.5 to 1.5 times / 25 mm.

28. If the glass yarn roll body of claim 25 or 26, wherein the value obtained by dividing the yarn width of the said glass yarn by TEX is in the range of 10 to 30.

29. A glass yarn, which is used in the weaving of glass cloth, the silicon (Si) content in the glass yarn is 95.0~100 mass% converted by silicon dioxide (SiO2), the kink index of the glass yarn is less than 400 mm, and the glass yarn satisfies the range of y≥9% (A) (C) 0.0003 ppm≤y≤0.50 ppm x: Silicon content in conversion of silicon dioxide (SiO2) y: Total content of uranium and titanium z: Total content of elements other than silicon, uranium, and thorium.

30. As in the glass yarn of claim 29, wherein the kinking index of the said glass yarn is 70 mm or more.

31. As in the glass yarn of claim 29, wherein y indicating the combined amount of the contents of uranium and titanium as described above is in the range of 0.0003 to 0.0010 ppm.

32. As in the glass yarn of claim 29, wherein the y of the combined amount of the contents of uranium and titanium indicated above is in the range of more than 0.0010 and less than 0.0015 ppm.

33. As in the glass yarn of claim 29, wherein the y of the combined amount of the contents of uranium and titanium indicated above is in the range of more than 0.0015 and less than 0.0018 ppm.

34. As in the glass yarn of claim 29, wherein the combined y of the contents of uranium and titanium indicated above is in the range of more than 0.0018 and less than 0.0035 ppm.

35. As in the glass yarn of claim 29, wherein the y of the combined amount of the contents of uranium and titanium indicated above is in the range of more than 0.0035 and less than 0.0040 ppm.

36. The glass yarn of claim 29, wherein the summation of the contents of the uranium and thorium is in the range of more than 0.0040 and less than 0.09 ppm.

37. The glass fiber as claimed in claim 29, wherein the y, representing the aggregate content of the uranium and thorium, is in the range of more than 0.09 and less than 0.12 ppm.

38. The glass fiber as claimed in claim 29, wherein the summation of the contents of the uranium and thorium is in the range of more than 0.12 and less than 0.50 ppm.

39. The glass yarn as claimed in claim 29 or 30, wherein the twist index of the glass yarn is in the range of 330 to 400 mm.

40. The glass yarn as claimed in claim 29 or 30, wherein the twist index of the glass yarn is in the range of 300 to 329 mm.

41. The glass yarn as claimed in claim 29 or 30, wherein the twist index of the glass yarn is in the range of 220 to 299 mm.

42. The glass yarn as claimed in claim 29 or 30, wherein the twist index of the glass yarn is in the range of 200 to 219 mm.

43. The glass yarn as claimed in claim 29 or 30, wherein the twist index of the glass yarn is in the range of 125 to 199 mm.

44. The glass yarn as claimed in claim 29 or 30, wherein the twist index of the glass yarn is in the range of 110 to 124 mm.

45. The glass yarn as claimed in claim 29 or 30, wherein the twist index of the glass yarn is 110 mm or less.

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