JP2024119957A - Glass cloth manufacturing method and glass yarn - Google Patents

Abstract

[Problem] The object is to provide a method for producing low dielectric glass cloth having uniform quality, and a glass thread suitable for producing low dielectric glass cloth. [Solution] A method for producing glass cloth by weaving glass threads consisting of a plurality of glass filaments as warp threads and weft threads, in which the density of the glass threads that become the weft threads is 2.2 g/cm3 or more and less than 2.5 g/cm3, the thread width variation (thread width distribution coefficient) of the glass threads that become the weft threads is 0.003 or more and 0.013 or less, and/or the thread width distribution variation coefficient A, which indicates the thread width distribution variation of the glass threads that become the weft threads, is 0.0002 or more and 0.0015 or less. [Selected Figure] None

Description

The present invention relates to a method for manufacturing glass cloth and glass yarn.

With the recent development of the information and communication society, data communication and/or signal processing have become large-volume and high-speed, and the dielectric constant of printed wiring boards used in electronic devices has been significantly reduced. For this reason, many low-dielectric glass cloths have been proposed as glass cloths for use in printed wiring boards.

For example, the low dielectric glass cloth disclosed in Patent Document 1 realizes a low dielectric constant by blending a large amount _{of B2O3} in the glass composition compared to the E-glass cloth that has been commonly used conventionally, while at the same time adjusting the blending amounts of other components such as _SiO2 .

Japanese Patent Application Publication No. 11-292567

As a result of the inventors' investigations, it has been found that low dielectric glass cloth made from such low dielectric glass yarns varies greatly in performance and quality compared to conventionally used E-glass cloth. Such variation in performance and quality of glass cloth also affects the quality of prepregs, laminates for printed wiring boards, etc. obtained using the same.

The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a method for producing a low dielectric glass cloth having uniform quality, and a glass yarn suitable for producing a low dielectric glass cloth.

As a result of intensive research into solving the above-mentioned problems, the inventors discovered that the above-mentioned problems can be solved by setting the width of the glass yarn, the range of variation in the yarn width, and the uniformity of the range of variation in the yarn width to specific ranges, and thus completed the present invention.

That is, the present invention is as follows.
[1]
A method for producing a glass cloth, which is produced by weaving glass yarns consisting of a plurality of glass filaments as warp yarns and weft yarns, comprising the steps of:
The density of the glass yarn to be the weft yarn is 2.2 g/ ^cm3 or more and less than 2.5 g/ ^cm3 ,
The yarn width dispersion coefficient indicating the yarn width variation of the glass yarn which becomes the weft yarn is 0.003 or more and
and/or
The yarn width distribution variation coefficient A, which indicates the yarn width distribution variation of the glass yarn that becomes the weft yarn, is 0
0.0002 or more and 0.0015 or less,
A method for manufacturing glass cloth.
Yarn width distribution coefficient = Value obtained by dividing the standard deviation of the yarn width (yarn width standard deviation A) by the average diameter of the glass filaments. Yarn width distribution variation coefficient A = Value obtained by dividing the standard deviation of the yarn width standard deviation B (yarn width distribution standard deviation) when the standard deviation of the yarn width (yarn width standard deviation B) is calculated for every 0.5 m length, by the diameter of the glass filaments constituting the weft yarn [2]
The density of the glass yarn is more than 2.2 g/ ^cm3 and less than 2.5 g/ ^cm3 ;
The yarn width dispersion coefficient is greater than 0.003 and less than 0.010;
And/or, the yarn width distribution variation coefficient A is more than 0.0003 and less than 0.0012;
A method for producing the glass cloth according to [1].
[3]
The yarn width distribution coefficient is 0.005 or more and 0.013 or less,
The yarn width distribution variation coefficient A is 0.0006 or more and 0.0015 or less,
And/or, the yarn width distribution variation coefficient B, which indicates the yarn width distribution variation of the glass yarn that becomes the weft yarn, is 0.013 or more and 0.027 or less;
A method for producing the glass cloth according to [1].
Yarn width distribution variation coefficient B = A value obtained by dividing the standard deviation of the yarn width standard deviation B (yarn width distribution standard deviation) by the average value of the yarn width standard deviation B when the yarn width standard deviation B is calculated for each 0.5 m length, and dividing the yarn width distribution CV value by the diameter of the glass filaments constituting the weft yarn [4]
The average number of twists per 25 mm of the weft is 0.50 or more and 1.20 or less,
The standard deviation indicating the variation in the number of twists is 0.10 or more and 0.20 or less.
The method for producing a glass cloth according to any one of [1] to [3].
[5]
The weft yarn is a glass yarn in which 80 to 120 glass filaments having an average diameter of more than 4.5 μm and not more than 5.5 μm are bundled together, and the average yarn width of the glass yarn is 90 μm or more and 130 μm or less.
0 μm or less,
The method for producing a glass cloth according to any one of [1] to [4].
[6]
The weft yarn is made of 180 glass filaments having an average diameter of more than 4.5 μm and not more than 5.5 μm.
The glass yarn is a bundle of 220 or more glass yarns, and the average yarn width of the glass yarn is 120 μm.
or more and 175 μm or less;
The method for producing a glass cloth according to any one of [1] to [4].
[7]
The weft yarn is made of 180 glass filaments having an average diameter of more than 5.5 μm and not more than 6.5 μm.
The glass yarn is a bundle of 220 or more glass yarns, and the average yarn width of the glass yarn is 155 μm or more and 195 μm or less.
The method for producing a glass cloth according to any one of [1] to [4].
[8]
The weft yarn is made of 180 glass filaments having an average diameter of more than 6.5 μm and not more than 7.5 μm.
The glass yarn is a bundle of 220 or more glass yarns, and the average yarn width of the glass yarn is 180 μm or more and 220 μm or less.
The method for producing a glass cloth according to any one of [1] to [4].
[9]
The elastic modulus of the glass yarn is 50 to 70 GPa;
The method for producing a glass cloth according to any one of [1] to [8].
[10]
The elastic modulus of the glass yarn is 50 to 63 GPa;
The method for producing the glass cloth according to [9].
[11]
The glass cloth has a dielectric constant of 5.0 or less at a frequency of 1 GHz.
The method for producing a glass cloth according to any one of [1] to [10].
[12]
The glass yarn,
The Si content is 40 to 60 mass% in terms of _SiO2 ,
The B content is 15 to ₃₀ mass% calculated as _B2O3 .
The method for producing a glass cloth according to any one of [1] to [11].
[13]
The density is 2.2 g/ ^cm3 or more and less than 2.5 g/ ^cm3 ,
The yarn width distribution coefficient indicating the yarn width variation is 0.003 or more and 0.013 or less, and/or
The yarn width distribution variation coefficient A, which indicates the distribution variation of the yarn width, is 0.0002 or more and 0.0015 or less;
Glass thread.
Yarn width dispersion coefficient = Value obtained by dividing the standard deviation of the yarn width (yarn width standard deviation A) by the average diameter of the glass filaments. Yarn width distribution variation coefficient A = Value obtained by dividing the standard deviation of the yarn width standard deviation B (yarn width distribution standard deviation) when the standard deviation of the yarn width (yarn width standard deviation B) is calculated for every 0.5 m length, by the diameter of the glass filaments constituting the weft yarn [14]
The density of the glass yarn is more than 2.2 g/ ^cm3 and less than 2.5 g/ ^cm3 ;
The yarn width dispersion coefficient is greater than 0.003 and less than 0.010;
And/or, the yarn width distribution variation coefficient A is more than 0.0003 and less than 0.0012;
The glass yarn according to [13].
[15]
The yarn width distribution coefficient is 0.005 or more and 0.013 or less,
The yarn width distribution variation coefficient A is 0.0006 or more and 0.0015 or less,
And/or, the yarn width distribution variation coefficient B, which indicates the yarn width distribution variation of the glass yarn that becomes the weft yarn, is 0.013 or more and 0.027 or less;
The glass fiber according to [13].
Yarn width distribution variation coefficient B = A value obtained by dividing the standard deviation of the yarn width standard deviation B (yarn width distribution standard deviation) (yarn width standard deviation B) calculated for each 0.5 m length by the average value of the yarn width standard deviation B, and dividing the yarn width distribution CV value by the diameter of the glass filaments constituting the weft [16]
The average number of twists per 25 mm is 0.50 or more and 1.20 or less,
The standard deviation indicating the variation in the number of twists is 0.10 or more and 0.20 or less.
The glass fiber according to any one of [13] to [15].
[17]
A glass yarn in which 80 to 120 glass filaments having an average diameter of more than 4.5 μm and not more than 5.5 μm are bundled together, and the average yarn width is 90 μm to 130 μm.
The glass fiber according to any one of [13] to [16].
[18]
180 to 220 glass filaments with an average diameter of 4.5 μm to 5.5 μm
The glass yarn is bundled in a number of strands or less, and the average yarn width is 120 μm or more and 175 μm or less.
The glass fiber according to any one of [13] to [16].
[19]
180 to 220 glass filaments with an average diameter of 5.5 μm to 6.5 μm
The glass yarn is bundled in a number of strands or less, and the average yarn width is 155 μm or more and 195 μm or less.
The glass fiber according to any one of [13] to [16].
[20]
180 to 220 glass filaments with an average diameter of more than 6.5 μm and less than 7.5 μm
The glass yarn is bundled in a number of strands or less, and the average yarn width is 180 μm or more and 220 μm or less.
The glass fiber according to any one of [13] to [16].
[21]
The elastic modulus is 50 to 70 GPa.
The glass fiber according to any one of [13] to [20].
[22]
The elastic modulus is 50 to 63 GPa.
The glass fiber according to any one of [13] to [20].
[23]
having a dielectric constant of 5.0 or less at a frequency of 1 GHz;
The glass fiber according to any one of [13] to [22].
[24]
The Si content is 40 to 60 mass% in terms of _SiO2 ,
The B content is 15 to ₃₀ mass% calculated as _B2O3 .
The glass fiber according to any one of [13] to [23].

According to the present invention, it is possible to provide a method for producing a low dielectric glass cloth having uniform quality, and a glass yarn suitable for producing a low dielectric glass cloth.

FIG. 2 is a perspective view showing one aspect of a weaving step in the manufacturing method of the present embodiment.

The following describes in detail an embodiment of the present invention (hereinafter referred to as the "present embodiment"); however, the present invention is not limited to this embodiment, and various modifications are possible without departing from the gist of the present invention.

[Method of manufacturing glass cloth]
The method for producing a glass cloth of the present embodiment is a method for producing a glass cloth obtained by weaving glass yarns consisting of a plurality of glass filaments as warp yarns and weft yarns, in which the density of the glass yarns that become the weft yarns is 2.2 g/ ^cm3 or more and less than 2.5 g/ ^cm3 , the yarn width distribution coefficient indicating the yarn width variation of the glass yarns that become the weft yarns is 0.003 or more and 0.013 or less, and/or the yarn width distribution variation coefficient A indicating the yarn width distribution variation of the glass yarns that become the weft yarns is 0.0002 or more and 0.0015 or less.

It has been found that glass cloth manufactured using low-dielectric glass yarns has a variation in quality compared to conventional E-glass cloth, and glass cloth of poor quality is occasionally obtained. A detailed examination of glass cloths of relatively poor quality among them revealed that they have in common that the glass yarns have unevenly distributed wide and narrow parts, and that they use glass yarns with a large variation in yarn width. Furthermore, glass cloths made of glass yarns with a large variation in yarn width distribution like this have many weaving defects, such as parts where the filaments constituting the glass yarns are partially broken and look like fluff, and parts where the weft yarns are loose.

The reason for this is not limited, but it is thought that glass yarns (weft yarns) that have an uneven distribution of wide and narrow parts have difficulty in obtaining a stable flight trajectory when woven, and are difficult to pass straight between warp yarns, which makes them prone to producing fuzz and weaving defects.

Furthermore, the E-glass glass yarns that have been used up until now are heavier than low-dielectric glass yarns, and variations in yarn width have had little effect on weaving. However, with lighter low-dielectric glass yarns, the weft yarn is more susceptible to the effects of the shape of the yarn width when woven, which is thought to promote the occurrence of fuzz and weaving defects.

Moreover, the low dielectric glass yarn, which has a small elastic modulus and is not strong against mechanical load, is likely to cause filament breakage and promote the generation of fluff. These effects are thought to be reflected in the quality of the woven glass cloth.

In contrast, in this embodiment, the density of the glass yarn is 2.2 g/cm ³ or more.
A weft yarn having a density of less than 5 g/ ^cm3 , and a variation range of the weft yarn width (yarn width dispersion coefficient) of 0.
0.003 or more and 0.013 or less, or the distribution range of the weft width (yarn width distribution variation coefficient A) is 0.0
By using a weft yarn having a dielectric constant of 0.002 or more and 0.0015 or less, the influence of the shape of the yarn width during weaving can be reduced even when a relatively light glass yarn with low dielectric constant is used. This makes it possible to suppress the occurrence of fluff and weaving defects and obtain glass cloth of uniform quality.

(Glass yarn density)
The density of the glass yarn of the weft is 2.2 g/cm ³ or more and less than 2.5 g/cm ³ , preferably more than 2.2 g/cm ³ and less than 2.5 g/cm ³ , and more preferably 2.22 g/cm ^{3 .}
More preferably, the density is 2.25 g/cm3 ^or more and 2.4 g/ ^cm3 or less.
cm ³ or less. If the density of the glass yarn of the weft is less than 2.5 g/cm ³ , the flying trajectory is easily affected by the shape of the glass yarn when the weft is woven on the discharged air, and quality defects such as fluff and weaving defects are likely to occur. However, by setting the yarn width dispersion coefficient and yarn width distribution variation coefficient A of the weft within the specific range of the present invention, the flying trajectory can be stabilized, and a high-quality glass cloth can be stably obtained. If the density of the glass yarn of the weft is 2.2 g/cm ³ or more, when the yarn width variation range and yarn width distribution variation range of the weft are within the range of the present invention, the flying trajectory of the weft can be stabilized. The glass density of the warp may be the same as or different from the above range, but it is preferable that it is in the same range from the viewpoint of uniforming the properties such as the air permeability, resin impregnation, resin adhesion, and electrical properties of the glass cloth, and from the viewpoint of obtaining a low dielectric glass cloth. The density of the glass yarn can be determined as the density of a lump of glass per cm ³ .

(Weft yarn bundle width dispersion coefficient)
The yarn width distribution coefficient of the weft yarn bundle is 0.003 or more, preferably more than 0.003, more preferably 0.004 or more, even more preferably 0.005 or more, still more preferably 0.006 or more, and particularly preferably 0.007 or more. The yarn width distribution coefficient of the weft yarn bundle is 0.013 or less, preferably less than 0.010, and more preferably 0.009 or less. When the yarn width distribution coefficient is within the above range, the weft yarn can be inserted with a stable flight trajectory from the weft-in side to the opposite side without requiring excessive air pressure when the weft yarn is driven in with an air jet loom, and therefore a high-quality glass cloth with little fuzz or weaving defects can be stably obtained.

The yarn width distribution coefficient of the yarn bundle is a value obtained by dividing the standard deviation of the yarn width measurement value of the yarn bundle by the average diameter of the glass filaments constituting the yarn bundle. The yarn width distribution coefficient of the warp yarn bundle may be the same as or different from the above range, but is preferably in the same range from the viewpoint of further suppressing the occurrence of fluff and weaving defects.
Yarn width dispersion coefficient = Value obtained by dividing the standard deviation of the yarn width (yarn width standard deviation A) by the average diameter of the glass filaments

(Weft width distribution variation coefficient A)
The weft width distribution variation coefficient A is 0.0002 or more, preferably more than 0.0003, and more preferably 0.0004 or more.
015 or less, preferably less than 0.0012, more preferably 0.0010 or less. By having the yarn width distribution variation coefficient A within the above range, the weft yarn can easily fly straight and stably without disturbance of the flight trajectory, and a high-quality glass cloth with less fluff and weaving defects can be stably obtained. This is presumed to be because the weft yarn can receive compressed air uniformly in the length direction. In addition, by having the yarn width distribution variation coefficient A within the above range, the unwinding resistance when unwinding the yarn bundle from the bobbin is within a small range, and a high-quality glass cloth with less fluff and weaving defects can be stably obtained. This is presumed to be because excessive overlapping of the yarns on the bobbin around which the yarn is wound can be avoided. If the yarn bundle is frayed during unwinding and one or several filaments are separated, the filaments will break at this site during weaving or subsequent processes, resulting in fluff and weaving defects.

When it is desired to stabilize the flight characteristics of the weft yarn and to place more importance on weaving productivity, the weft yarn width distribution variation coefficient A is 0.0002 or more and 0.0015 or less, and preferably 0.0006 or more and 0.0015 or less.

The yarn width distribution variation coefficient A of the yarn bundle is a value obtained by calculating the yarn width distribution state in a large length range (e.g., 50 m) as the standard deviation (standard deviation B = standard deviation of standard deviation A) using the standard deviation (standard deviation A) of yarn width measurements in a specific small length range (e.g., 0.5 m), and dividing the result by the average diameter of the filaments constituting the yarn bundle. The yarn width distribution variation coefficient A of the warp yarn bundle is
The range may be the same as or different from the above range, but from the viewpoint of further suppressing the occurrence of fuzz and weaving defects, the range is preferably the same.
Coefficient of variation of yarn width distribution A = A value obtained by dividing the standard deviation of yarn width standard deviation B (yarn width distribution standard deviation) when the standard deviation of yarn width (yarn width standard deviation B) is calculated for every 0.5 m length by the diameter of the glass filaments constituting the weft yarn

It is preferable that both the yarn width dispersion coefficient and the yarn width distribution variation coefficient A of the yarn bundle are within the above range.

The yarn width distribution coefficient, yarn width distribution variation coefficient A, and average value of the yarn bundle can be calculated from the yarn width data obtained by measuring the yarn width of a glass yarn of 10 m or more at equal intervals shorter than 1 mm.

The method for measuring the yarn width in this case is not particularly limited, but for example, a method can be used in which an LED beam is irradiated from the side and the yarn width of the glass yarn is obtained from the projected width of the portion where the LED beam is blocked by the glass yarn, and the glass yarn can be continuously measured while being continuously conveyed. The yarn width can also be measured while observing it under a microscope.

(Weft width distribution variation coefficient B)
The yarn width distribution variation coefficient B, which indicates the yarn width distribution variation of the glass yarn serving as the weft yarn, is preferably 0.013 or more, more preferably 0.014 or more, and even more preferably 0.0
The yarn width distribution variation coefficient B is preferably 0.027 or less, more preferably 0.024 or less, and even more preferably 0.021 or less. When the yarn width distribution variation coefficient B is within the above range, the flying stability of the weft yarn tends to be further improved.

Yarn width distribution variation coefficient B = A value obtained by dividing the yarn width distribution CV value, which is obtained by dividing the standard deviation of the yarn width standard deviation B (yarn width distribution standard deviation) by the average value of the yarn width standard deviation B when the yarn width standard deviation B is calculated for each 0.5 m length, by the diameter of the glass filaments constituting the weft yarn.

(Average yarn width)
In the manufacturing method of the glass cloth of the present invention, when a glass cloth having a thickness of 20 μm or more and 38 μm or less is manufactured, it is preferable that a glass yarn formed by bundling 80 to 120 glass filaments having an average diameter of more than 4.5 μm and not more than 5.5 μm is used as a weft yarn, and the average yarn width of the weft yarn is 90 μm or more and 130 μm or less. In this case, the average yarn width is more preferably 95 μm or more, even more preferably 100 μm or more, and particularly preferably 102 μm or more. Moreover, the average yarn width is more preferably 125 μm or less, even more preferably 122 μm or less, and particularly preferably 120 μm or less.

In the case of producing a glass cloth having a thickness of 39 μm or more and 63 μm or less, it is preferable to use a glass yarn formed by bundling 180 to 220 glass filaments having an average diameter of more than 4.5 μm and not more than 5.5 μm as a weft yarn, and the average yarn width of the weft yarn is preferably 120 μm or more and 175 μm or less. In this case, the average yarn width is more preferably 125 μm or more, and even more preferably 130 μm or more. The average yarn width is more preferably 170 μm.
The thickness is preferably 165 μm or less, more preferably 165 μm or less, and particularly preferably 150 μm or less.

In the case of producing a glass cloth having a thickness of 64 μm or more and 83 μm or less, it is preferable to use a glass yarn formed by bundling 180 to 220 glass filaments having an average diameter of more than 5.5 μm and not more than 6.5 μm as a weft yarn, and the average yarn width of the weft yarn is preferably 155 μm or more and 195 μm or less. In this case, the average yarn width is more preferably 160 μm or more, and even more preferably 162 μm or more. The average yarn width is more preferably 191 μm.
The thickness is preferably 183 μm or less, more preferably 183 μm or less, and particularly preferably 170 μm or less.

In the case of producing a glass cloth having a thickness of 84 μm or more and 100 μm or less, it is preferable to use a glass yarn formed by bundling 180 to 220 glass filaments having an average diameter of more than 6.5 μm and not more than 7.5 μm as a weft yarn, and the average yarn width of the weft yarn is preferably 180 μm or more and 220 μm or less. In this case, the average yarn width is more preferably 185 μm or more, and even more preferably 190 μm or more. The average yarn width is more preferably 215 μm or more.
It is preferably 210 μm or less, and more preferably 210 μm or less.

By setting the average yarn width of the weft yarn to the above upper limit or less, even if there is variation in the yarn width, the effect of the variation is small, and the occurrence of fuzz and weaving defects in the obtained glass cloth tends to be suppressed. In addition, by setting the average yarn width to the above lower limit or more, the glass yarn is appropriately exposed to the injected air during weft driving, and the weft can be blown with a relatively gentle injection pressure, so that the occurrence of fuzz and weaving defects in the obtained glass cloth tends to be suppressed. The average yarn width of the warp yarn may be the same as or different from the above range, but it is preferably in the same range from the viewpoint of further suppressing the occurrence of fuzz and weaving defects.

(Twist number variation)
The standard deviation showing the variation in the number of twists per 25 mm of the weft yarn is preferably 0.03 or more, more preferably 0.05 or more, and even more preferably 0.10 or more. The standard deviation showing the variation in the number of twists per 25 mm of the weft yarn is preferably 0.20 or less, more preferably 0.18 or less, and even more preferably 0.15 or less.
It is particularly preferably 0.13 or less. By having the standard deviation of the number of twists within the above range,
The effect of the shape of the yarn width during weaving is reduced, and the occurrence of fluff and weaving defects in the obtained glass cloth tends to be suppressed. In addition, by having the standard deviation of the twist number within the above range, the solder heat resistance tends to be excellent.

The standard deviation showing the variation in the number of twists per 25 mm of the warp yarn is preferably 0.03 or more, more preferably 0.05 or more, and even more preferably 0.10 or more. The standard deviation showing the variation in the number of twists per 25 mm of the warp yarn is preferably 0.20 or less, more preferably 0.18 or less, and even more preferably 0.15 or less.
It is particularly preferably 0.13 or less. It is preferable that the standard deviation of the twist number is within the above range from the viewpoint of further suppressing the occurrence of fluff and weaving defects. In addition, by having the standard deviation of the twist number within the above range, the solder heat resistance tends to be excellent. The standard deviations of the twist numbers of the weft and warp threads may be the same or different.

The reason why the standard deviation showing the variation in the number of twists per 25 mm of the weft and/or warp yarns is excellent in solder heat resistance is not particularly limited, but is thought to be as follows. When the standard deviation showing the variation in the number of twists is 0.10 or more, the adjacent yarns are prevented from being too close to each other, and a suitable gap is formed between the adjacent yarns, so that the resin impregnation into the glass cloth is good, and the adhesion between the glass yarn and the resin tends to be improved. Therefore, it is thought that the solder heat resistance is further improved. In addition, when the standard deviation showing the variation in the number of twists is 0.20 or less, the distribution of the glass yarns becomes more uniform in the obtained glass cloth and the substrate in which the glass cloth is impregnated with resin, and the occurrence of locally weak parts of physical properties tends to be suppressed. Therefore, it is thought that the solder heat resistance is further improved.

(Average number of twists)
The average number of twists per 25 mm of the weft yarn is preferably 0.50 to 1.20, more preferably 0.60 to 1.10, and even more preferably 0.65 to 1.
When the average twist number is within the above range, the effect of the shape of the yarn width during weaving is reduced, and the occurrence of fuzz and weaving defects in the obtained glass cloth tends to be suppressed.

The average number of twists per 25 mm of the warp yarn is preferably 0.50 or more and 1.20 or less, more preferably 0.60 or more and 1.10 or less, and even more preferably 0.65 or more and 1.
The average number of twists is preferably within the above range from the viewpoint of further suppressing the occurrence of fuzz and weaving defects. The average number of twists of the weft and warp may be the same or different.

(Constitution of glass yarn)
Next, the structure of the glass yarn will be described. The glass yarn is obtained by bundling a plurality of glass filaments and twisting them as necessary. In this case, the glass yarn is classified as a multifilament, and the glass filament is classified as a monofilament.

The average diameter of the glass filaments constituting the warp and weft is preferably 2.5 to 9 μm, more preferably 3.0 to 7.5 μm, and even more preferably 3.0 to 7.5 μm.
The average diameter of the glass filaments is 9 μm or less, which improves processability and allows for the realization of thin, high-density printed wiring boards. Also, the average diameter of the glass filaments is 3.5 μm or more, which makes the glass cloth less likely to break.

The elements constituting the glass filament are Si, B, Al, Ca, Mg, P, Na, K, and Ti.
, Zn, Fe, F, etc.

The Si content of the glass yarn is preferably 40 to 60 mass%, more preferably 45 to 55 mass%, and even more preferably 47 to 53 mass%, and more preferably 48 to 55 mass%, and even more preferably 49 to 54 _mass %, and even more preferably 50 to 55 mass%, and even more preferably 51 to 55 mass%, and even more preferably 52 to 55 mass%, and even more preferably 53 to 55 mass%, and even more preferably 54 to 55 mass%, and even more preferably 55 to 55 mass%, and even more preferably 56 to 55 mass%, and even more preferably 57 to 55 mass%, and even more preferably 58 to 55 mass%, and even more preferably 55 to 55 mass%, and even more preferably 56 to 55 mass%, and even more preferably 57 to 55 mass%, and even more preferably 57 to 55 mass%, and even more preferably 55 to 55 mass%, and even more preferably 5
2% by mass. Si is a component that forms the skeletal structure of the glass yarn, and when the Si content is 40% by mass or more, the strength of the glass yarn is improved, and the breakage of the glass cloth tends to be suppressed more in the manufacturing process of the glass cloth and the post-process such as the manufacturing of the prepreg using the glass cloth. In addition, when the Si content is 40% by mass or more, the dielectric constant of the glass cloth tends to be lowered more. On the other hand, when the Si content is 60% by mass or less, the viscosity at the time of melting is lowered more in the manufacturing process of the glass filament, and glass fibers with a more homogeneous glass composition tend to be obtained. For this reason, since it is difficult for the obtained glass filament to have a part that is easily devitrified or a part that is difficult to remove bubbles, it is difficult for the glass filament to have a part that is locally weak in strength, and as a result, the glass cloth composed of the glass yarn obtained by using this is difficult to break. The Si content can be adjusted according to the amount of raw material used for producing the glass filament.

The B content of the glass yarn, calculated _{as B2O3} , is preferably 15 to 30 mass%, more preferably 17 to 28 mass%, even more preferably 20 to 27 mass%, still more preferably 21 to 25 mass%, and even more preferably 21.5 to 24 mass%.
When the B content is 15% by mass or more, the dielectric constant tends to be further decreased.
By setting the content to 30% by mass or less, the moisture absorption resistance is improved, and the insulation reliability tends to be further improved. The B content can be adjusted according to the amount of raw material used in the production of the glass filament. If the amount of raw material may vary during the production of the glass filament, the amount of raw material charged can be adjusted in advance in anticipation of this.

The Al content of the glass filament is preferably 11 to 18 mass%, more preferably 11 to 16 mass%, and even more preferably 12 to 16 mass%, calculated as _Al2O3 . When the Al content is within the above range, _the electrical properties and strength tend to be improved. The Al content can be adjusted according to the amount of raw material used to prepare the glass filament.

The Ca content of the glass yarn is preferably 5 to 10 mass %, preferably 5 to 9 mass %, and more preferably 5 to 8.5 mass %, calculated as CaO. When the Ca content is 4 mass % or more, the viscosity at the time of melting is further reduced in the manufacturing process of the glass filament, and glass fibers having a more homogeneous glass composition tend to be obtained. In addition, when the Ca content is 10 mass % or less, the dielectric constant tends to be further improved. The Ca content can be adjusted according to the amount of raw material used in manufacturing the glass filament.

The above contents can be measured by ICP optical emission spectroscopy. Specifically, the Si content and B content can be obtained by melting a weighed glass cloth sample with sodium carbonate, dissolving it in dilute nitric acid to a constant volume, and measuring the obtained sample by ICP optical emission spectroscopy. The Fe content can be obtained by dissolving a weighed glass cloth sample by an alkali dissolution method to a constant volume, and measuring the obtained sample by ICP optical emission spectroscopy. Furthermore, the Al content, Ca content, and Mg content can be obtained by thermally decomposing a weighed glass cloth sample with sulfuric acid, nitric acid, and hydrogen fluoride, dissolving it in dilute nitric acid to a constant volume, and measuring the obtained sample by ICP optical emission spectroscopy. The ICP optical emission spectroscopy device can be PS3520VDD II manufactured by Hitachi High-Tech Science Corporation.

The elastic modulus of the glass yarn is preferably 50 to 70 GPa, more preferably 50 to 60 GPa.
The elastic modulus is preferably 3 GPa, and more preferably 53 to 63 GPa. When the elastic modulus is 50 GPa or more, the rigidity of the glass yarn is improved, and fluffing tends to be less likely to occur during the manufacturing process. When the elastic modulus is 70 GPa or less, the brittleness resistance of the glass yarn is improved, and fluffing tends to be less likely to occur during the manufacturing process. Furthermore, when the elastic modulus is within the above range, the glass yarn has appropriate flexibility, and when a mechanical load is applied, filament breakage and the like are less likely to occur, and fluffing and weaving defects tend to be less likely to occur.

The dielectric constant of the obtained glass cloth is preferably 5.0 or less at a frequency of 1 GHz, more preferably 4.8 or less, even more preferably 4.6 or less, and particularly preferably 4.0 or less. The dielectric constant can be measured, for example, by a cavity resonance method. In this embodiment, the dielectric constant refers to the dielectric constant at a frequency of 1 GHz unless otherwise specified. It is preferable that the dielectric constant of the glass cloth is 5.0 or less at a frequency of 1 GHz, since it can meet the demand for a low dielectric constant.

The method for producing the glass cloth of this embodiment is not particularly limited as long as it uses the weft yarn, but examples of the method include a yarn width adjusting step of adjusting the yarn width so that the yarn width distribution coefficient of the weft yarn is 0.003 to 0.013 and/or the yarn width variation displacement coefficient is 0.0002 to 0.0015, a weaving step of weaving the glass yarn to obtain a glass cloth, and a fiber opening step of opening the glass yarns of the glass cloth. In addition, if necessary, the method may include a desizing step of removing the sizing agent attached to the glass yarns of the glass cloth, and a surface treatment step with a silane coupling agent. Each step of this embodiment will be described in more detail below.

[Thread width adjustment process]
The yarn width adjustment step is performed by adjusting the yarn width distribution coefficient of the weft yarn to be used to 0.003 or more and 0.013 or less, and/or
More specifically, in the yarn width adjustment step, the yarn width distribution coefficient and/or the yarn width distribution coefficient A of the weft yarn are measured, and if the yarn width distribution coefficient is in the range of 0.003 to 0.013 and/or the yarn width distribution coefficient A is in the range of 0.0002 to 0.0015, the yarn is used in the subsequent weaving step, and if it is outside the range, the yarn is discarded or is untwisted or untwisted to such an extent that the yarn width distribution coefficient is in the range of 0.003 to 0.013 and/or the yarn width distribution coefficient A is 0.0
The coefficient of variation is adjusted to be in the range of 0.002 to 0.0015. Alternatively, it is also possible to provide feedback to the glass yarn manufacturing process and adjust the yarn manufacturing conditions. The width of the glass yarn is affected by the variation in the number of twists, such as the high and low twist density parts, and the variation in the width of the glass filaments. Therefore, the coefficient of variation of the glass yarn to be used in the weaving process can be adjusted by untwisting or untwisting. Furthermore, when the quality of the glass yarn exceeds the range of the coefficient of variation that can be adjusted by twisting as a result of measuring the coefficient of variation distribution A of the weft yarn, the glass yarn itself can be replaced as part of the adjustment of the coefficient of variation.

[Weaving process]
The weaving process is a process in which glass yarns are woven to obtain glass cloth. The weaving method is not particularly limited as long as it is a method of weaving warp and weft yarns to obtain a predetermined weaving structure. The weaving structure of the glass cloth is not particularly limited, but examples thereof include plain weave, sash weave, satin weave, twill weave, etc. Among these, the plain weave structure is more preferable.

Fig. 1 is a perspective view showing one aspect of the weaving process in the manufacturing method of this embodiment. Fig. 1 is a diagram showing one aspect of the weaving process by the air jet loom method, in which warp threads 1 drawn in parallel are opened above and below, and a weft thread 4 fed from a weft storage device 2 is sent through the opening by a jet flow from a nozzle 3 to weave. In this weaving process, it is difficult to send out a weft thread straight if it is light and has a large thread width distribution coefficient and/or thread width distribution variation coefficient A, and the resulting glass cloth may have fuzz or weaving defects. In contrast, in this embodiment, the thread width distribution coefficient is set to 0.003 to 0.013 by undergoing the above-mentioned thread width adjustment process, etc.
And/or, by using a weft yarn having a yarn width distribution variation coefficient A of 0.0002 to 0.0015, the occurrence of fuzz and weaving defects is suppressed when the weft yarn is woven in. This makes it possible to improve the in-plane uniformity and lot-to-lot uniformity of the quality of the glass cloth. Note that the weaving method is not limited to the air jet loom method, and may be a water jet loom method or a shuttle method.

The density of the warp and weft threads constituting the glass cloth is preferably 30 to 120 threads/
inch, more preferably 40 to 110 pieces/inch, and further preferably 5
The density of the warp threads can be controlled by adjusting the interval between the warp threads drawn in parallel, and the density of the weft threads can be controlled by the number of times the weft threads are ejected from the nozzle per unit time and the flow speed of the warp threads.

The thickness of the glass cloth finally obtained through the fiber opening process is preferably 8 to 10 mm.
0 μm, more preferably 9 to 90 μm, and even more preferably 9.5 to 80 μm.
When the thickness of the glass cloth is within the above range, a thin glass cloth having relatively high strength tends to be obtained.

The fabric weight (weight per unit area) of the glass cloth is preferably 8 to 250 g/ ^m2 , more preferably 8 to 130 g/ ^m2 , further preferably 8 to 100 g/ ^m2 , and particularly preferably 8 to 90 g/ ^m2 .

[Opening process]
The opening step is a step of opening the glass yarns of the glass cloth. The opening method is not particularly limited, but examples thereof include opening processing methods using spray water (high pressure water opening), a vibro washer, ultrasonic water, a mangle, etc.

[Desizing process]
The desizing step is a step of removing the sizing agent attached to the glass yarn of the glass cloth. The desizing method is not particularly limited, but may be, for example, a method of removing the sizing agent by heating.

[Surface treatment process]
The surface treatment step is a step of performing a surface treatment using a silane coupling agent. The surface treatment method includes contacting a surface treatment agent containing a silane coupling agent with a glass cloth,
Examples of the method for bringing the surface treatment agent into contact with the glass cloth include a method for immersing the glass cloth in the surface treatment agent, and a method for applying the surface treatment agent to the glass cloth using a roll coater, a die coater, a gravure coater, or the like. The method for drying the surface treatment agent is not particularly limited, and examples thereof include hot air drying and drying methods using electromagnetic waves.

(Surface Treatment)
The glass cloth may be surface-treated with a surface treatment agent. The surface treatment agent is not particularly limited, but may be, for example, a silane coupling agent, and may be used in combination with water, an organic solvent, an acid, a dye, a pigment, a surfactant, or the like, as necessary.

The silane coupling agent is not particularly limited, but examples thereof include compounds represented by formula (1).
X(R) _3-n SiY _n ...(1)
(In formula (1), X is an organic functional group having at least one of an amino group and an unsaturated double bond group, each Y is independently an alkoxy group, n is an integer of 1 to 3, and each R is independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group.)

X is preferably an organic functional group having at least three or more of amino groups and unsaturated double bond groups, and more preferably an organic functional group having at least four or more of amino groups and unsaturated double bond groups.

The alkoxy group may take any form, but from the viewpoint of stabilizing the treatment of the glass cloth, an alkoxy group having 5 or less carbon atoms is preferred.

Specific examples of the silane coupling agent include N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropylmethyldimethoxysilane and its hydrochloride,
N-β-(N-di(vinylbenzyl)aminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-di(vinylbenzyl)aminoethyl)-N-γ-
(N-vinylbenzyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-
β-(N-benzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-benzylaminoethyl)-γ-aminopropyltriisoethoxysilane and its hydrochloride, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-
Examples of the silane include known simple substances such as (2-aminoethyl)aminopropyltriethoxysilane, aminopropyltrimethoxysilane, vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, and acryloxypropyltrimethoxysilane, and mixtures of these.

The molecular weight of the silane coupling agent is preferably 100 to 600, more preferably 150 to 500, and even more preferably 200 to 450. Among these, it is preferable to use two or more types of silane coupling agents having different molecular weights. By treating the surface of the glass yarn with two or more types of silane coupling agents having different molecular weights, the density of the surface treatment agent on the surface of the glass cloth tends to be increased, and the reactivity with the matrix resin tends to be further improved.

[Other methods for producing glass cloth]
In another aspect of the present embodiment, a method for producing a glass cloth is provided, which is produced by weaving a glass yarn consisting of a plurality of glass filaments as a warp yarn and a weft yarn, and further comprises:
The average number of twists per 5 mm is 0.50 to 1.20, the standard deviation of the number of twists is 0.03 to 0.18, and the density of the glass yarn to be the weft is 2.2 g/
A manufacturing method in which the density is 2.5 g/cm3 or more and less than ^2.5 g/ ^cm3 may be used.

[Glass thread]
The glass yarn of the present embodiment is the glass yarn used in the above-mentioned method for producing a glass cloth, in particular the glass yarn used as a weft yarn. The configuration of the glass yarn may be the same as that described above.

The glass cloth of the present embodiment is obtained by the above-mentioned glass cloth manufacturing method, and has the above-mentioned glass yarns at least as weft yarns.

[Prepreg]
The prepreg of this embodiment has the glass cloth obtained as described above and the matrix resin composition impregnated into the glass cloth. The prepreg having the glass cloth has little variation in quality and high yield of the final product. In addition, it is possible to provide a printed wiring board having excellent dielectric properties and excellent moisture absorption resistance, and therefore the variation in dielectric constant is small under the influence of the usage environment, especially in a high humidity environment.

The prepreg of the present embodiment can be produced by a conventional method, for example, by impregnating the glass cloth of the present embodiment with a varnish prepared by diluting a matrix resin such as an epoxy resin with an organic solvent, volatilizing the organic solvent in a drying furnace, and curing the thermosetting resin to a B-stage state (semi-cured state).

As the matrix resin composition, in addition to the above-mentioned epoxy resins, bismaleimide resins,
Thermosetting resins such as cyanate ester resins, unsaturated polyester resins, polyimide resins, BT resins, and functionalized polyphenylene ether resins; polyphenylene ether resins, polyetherimide resins, liquid crystal polymers (LCPs) of wholly aromatic polyesters, polybutadienes,
Thermoplastic resins such as fluororesins; and mixed resins thereof. From the viewpoint of improving dielectric properties, heat resistance, solvent resistance, and press moldability, the matrix resin composition may be a resin obtained by modifying a thermoplastic resin with a thermosetting resin.

The matrix resin composition may also contain inorganic fillers such as silica and aluminum hydroxide; flame retardants such as bromine-based, phosphorus-based, and metal hydroxides; silane coupling agents; heat stabilizers; antistatic agents; ultraviolet absorbers; pigments; colorants; lubricants, etc.

[Printed Wiring Board]
The printed wiring board of this embodiment includes the prepreg. The printed wiring board including the prepreg of this embodiment has less variation in quality and a high yield of the final product. In addition, since the prepreg has excellent dielectric properties and excellent moisture absorption resistance, it has the effect of being less susceptible to the influence of the usage environment, particularly in a high humidity environment, and thus has little variation in the dielectric constant.

The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[Physical properties of glass cloth]
The physical properties of the glass cloth, specifically, the thickness of the glass cloth, the diameter of the filaments constituting the warp and weft, the number of filaments, and the weaving density of the warp and weft (weaving density) are in accordance with JIS R
The measurement was performed in accordance with 3420.

[Elastic modulus]
The elastic modulus was measured by the pulse-echo overlap method.

[Glass yarn composition]
The composition of the glass yarn was measured by ICP emission spectrometry.
The content and B content were obtained by fusing a weighed out glass cloth sample with sodium carbonate, dissolving it in dilute nitric acid to a constant volume, and measuring the resulting sample by ICP emission spectrometry.
The Fe content was obtained by dissolving the weighed glass cloth sample by an alkali dissolution method, adjusting the volume, and measuring the obtained sample by ICP emission spectrometry.
The Ca content and Mg content were measured by thermally decomposing a weighed glass cloth sample with sulfuric acid, nitric acid, and hydrogen fluoride, dissolving it in dilute nitric acid, adjusting the volume, and measuring the resulting sample by ICP optical emission spectrometry. Note that the ICP optical emission spectrometry used was PS3520VDD II manufactured by Hitachi High-Tech Science Corporation.

[Measurement of standard deviation A and average value of yarn width]
The glass yarn was conveyed at a speed of 1 m/min.
IGH ACCURACY CMOS MICROMETER LS-9006MR /
The width of a 50 m glass yarn was measured using a measuring device (manufactured by Keyence Corporation), and the standard deviation of the width of the glass yarn (width standard deviation A) and the average width were calculated from the obtained width data.

The tension acting on the glass yarn when it is transported is measured using a tension meter (manufactured by SCHMIDT).
The tension is measured using a 300 mm diameter hose (Control instruments ETPB-100-C0585).
Examples 1 to 18, Comparative Example 1, and Reference Examples 1 to 3 are 0.12 to 0.18 N
In Examples 19 to 29 and Comparative Examples 2 and 3, the pressure was 0.10 to 0.17 N.
In Examples 30 to 40 and Comparative Examples 4 and 5, the pressure was 0.08 to 0.16 N.
In Examples 41 to 48 and Comparative Examples 6 and 7, the pressure was 0.07 to 0.14 N.
It was.

[Measurement of yarn width standard deviation B and yarn width distribution standard deviation of yarn width]
The yarn width data of the 50 m glass yarn obtained as described above was divided into 100 equal parts in the length direction, and 100 pieces of yarn width data for every 0.5 m in length were obtained. Based on the yarn width data for every 0.5 m of the glass yarn, the standard deviation (yarn width standard deviation B) was calculated. Then, in order to confirm the variation of the yarn width standard deviation B, the standard deviation was calculated based on the obtained 100 yarn width standard deviations B, and the yarn width distribution standard deviation was obtained.

[Twist number variation]
The twist number of 50 cm of the glass yarn was measured using a twist detector (manufactured by Technos Co., Ltd.) and converted into the twist number per 25 mm. The standard deviation value calculated from 30 pieces of twist number data obtained (measurements were made at 10 points on the outer layer side of the bobbin, 10 points in the middle, and 10 points on the inner layer side) was taken as the variation in the twist number.

[Evaluation 1: fuzz, weaving defects quality]
From the glass cloth rolls obtained in the Examples and Comparative Examples, 1000 m of glass cloth was unwound, and the presence or absence of fluff and weaving defects was checked, and the quality was evaluated according to the following evaluation criteria.
5: Three or less fuzz or weaving defects were observed.
4: 3 to 5 fuzz or weaving defects were observed.
3: 6 to 15 fuzz or weaving defects were observed.
2: 15 to 30 pieces of fuzz or weaving defects were observed.
1: 30 or more pieces of fuzz or weaving defects were found.

[Evaluation 2: Weaving ability]
In the weaving process using the air jet loom in the Examples and Comparative Examples, the number of times that weaving was stopped during the weaving of 2100 pieces of glass cloth was counted, and the weaving properties were evaluated according to the following evaluation criteria.
5: 0 stops.
4: Stop 1 to 2 times.
3: Stop 3 to 4 times.
2: Stop 5 to 7 times.
1: 8 or more stops.

[Evaluation 3: Heat resistance]
The glass cloth obtained in each of the Examples and Comparative Examples was impregnated with polyphenylene ether resin varnish, and then the excess varnish was scraped off by passing the glass cloth through a specified slit. The glass cloth was then dried for a specified time in a drying oven at 105° C. to remove the toluene, thereby obtaining a prepreg.

Eight sheets of the obtained prepreg were stacked, and then a 12 μm thick sheet with a surface roughness of Rz 2.0 was applied to both sides of the stack.
Then, vacuum pressing was performed under conditions of a pressure of 5 kg/ ^cm2 while heating from room temperature at a temperature increase rate of 3°C/min, and when the temperature reached 130°C, vacuum pressing was performed under conditions of a pressure of 40 kg/ ^cm2 while heating at a temperature increase rate of 3°C/min, and when the temperature reached 200°C, vacuum pressing was performed under conditions of a pressure of 40 kg/ ^cm2 while maintaining the temperature at 200°C for 60 minutes to produce a copper-clad laminate.

The copper foil on one side was removed by etching, and a heat resistance test was performed. The test pieces were cut into 50 mm squares, placed in a 105°C oven and dried for 2 hours.
A pressure cooker test was carried out under conditions of 2 atm for 4 hours. Then, a heat resistance test was carried out in which the samples were dipped in a solder bath at 260° C. or 288° C. for 20 seconds 30 times.
The dip interval was 20 seconds.

The heat resistance test was evaluated by visual observation based on the following criteria.
5: Laminate in which no blistering, peeling, or whitening was observed under the condition of 288°C. 3: Laminate in which no blistering, peeling, or whitening was observed under the condition of 260°C. (Note that, under the condition of 288°C, any of blistering, peeling, or whitening occurred.)
1: Laminate that showed any of blistering, peeling, and whitening at 260°C

[Examples 1 to 18, Comparative Example 1, Reference Examples 1 to 3]
Glass yarns having the composition shown in Table 1 (average diameter of glass filaments: 5.0 μm, number of filaments: 100) were woven by an air jet loom at a warp density of 6.
A glass cloth having a weft density of 67/25 mm and a thickness of 30 μm was obtained. Next, a desizing treatment was performed by heating, and a fiber opening process was performed by a high-pressure water spray, followed by a surface treatment using a silane coupling agent to produce a glass cloth. Similarly, glass cloths were produced using E-glass as Reference Examples 1 to 3.

[Examples 19 to 29, Comparative Examples 2 and 3]
Glass yarns having the composition shown in Table 2 (average diameter of glass filaments: 5.0 μm, number of filaments: 200) were woven to a weaving density of 52.5/100 for the warp and weft, respectively.
A glass cloth having a length of 25 mm and a thickness of 45 μm was obtained.

[Examples 30 to 40, Comparative Examples 4 and 5]
Glass yarns having the composition shown in Table 2 (average diameter of glass filaments: 6.0 μm, number of filaments: 200) were woven to obtain a glass cloth having a warp yarn packing density of 59 yarns/25 mm, a weft yarn packing density of 61 yarns/25 mm, and a thickness of 70 μm.

[Examples 41 to 48, Comparative Examples 6 and 7]
Glass yarns having the composition shown in Table 2 (average diameter of glass filaments: 7.0 μm, number of filaments: 200) were woven to obtain a glass cloth having a warp yarn packing density of 60 yarns/25 mm, a weft yarn packing density of 57 yarns/25 mm, and a thickness of 88 μm.

INDUSTRIAL APPLICABILITY The present invention has industrial applicability as a method for producing glass cloth used for prepregs and the like.

Claims (24)

A method for producing a glass cloth, which is produced by weaving glass yarns consisting of a plurality of glass filaments as warp yarns and weft yarns, comprising the steps of:
The density of the glass yarn to be the weft yarn is 2.2 g/ ^cm3 or more and less than 2.5 g/ ^cm3 ,
The yarn width dispersion coefficient indicating the yarn width variation of the glass yarn which becomes the weft yarn is 0.003 or more and
and/or
The yarn width distribution variation coefficient A, which indicates the yarn width distribution variation of the glass yarn that becomes the weft yarn, is 0
0.0002 or more and 0.0015 or less,
A method for manufacturing glass cloth.
Yarn width dispersion coefficient = Value obtained by dividing the standard deviation of the yarn width (yarn width standard deviation A) by the average diameter of the glass filaments. Yarn width distribution variation coefficient A = Value obtained by dividing the standard deviation of the yarn width standard deviation B (yarn width distribution standard deviation) when the standard deviation of the yarn width (yarn width standard deviation B) is calculated for every 0.5 m length, by the diameter of the glass filaments constituting the weft. The density of the glass yarn is more than 2.2 g/ ^cm3 and less than 2.5 g/ ^cm3 ;
The yarn width dispersion coefficient is greater than 0.003 and less than 0.010,
And/or, the yarn width distribution variation coefficient A is more than 0.0003 and less than 0.0012;
The method for producing the glass cloth according to claim 1 . The yarn width distribution coefficient is 0.005 or more and 0.013 or less,
The yarn width distribution variation coefficient A is 0.0006 or more and 0.0015 or less,
And/or, the yarn width distribution variation coefficient B, which indicates the yarn width distribution variation of the glass yarn that becomes the weft yarn, is 0.013 or more and 0.027 or less;
The method for producing the glass cloth according to claim 1 .
Yarn width distribution variation coefficient B = A value obtained by dividing the yarn width distribution CV value, which is obtained by dividing the standard deviation of the yarn width standard deviation B (yarn width distribution standard deviation) by the average value of the yarn width standard deviation B when the yarn width standard deviation B is calculated for each 0.5 m length, by the diameter of the glass filaments constituting the weft yarn. The average number of twists per 25 mm of the weft is 0.50 or more and 1.20 or less,
The standard deviation indicating the variation in the number of twists is 0.10 or more and 0.20 or less.
The method for producing the glass cloth according to any one of claims 1 to 3. The weft yarn is a glass yarn in which 80 to 120 glass filaments having an average diameter of more than 4.5 μm and not more than 5.5 μm are bundled together, and the average yarn width of the glass yarn is 90 μm or more and 130 μm or less.
0 μm or less,
The method for producing the glass cloth according to any one of claims 1 to 4. The weft yarn is made of 180 glass filaments having an average diameter of more than 4.5 μm and not more than 5.5 μm.
The glass yarn is a bundle of 220 or more glass yarns, and the average width of the glass yarn is 120 μm.
or more and 175 μm or less;
The method for producing the glass cloth according to any one of claims 1 to 4. The weft yarn is made of 180 glass filaments having an average diameter of more than 5.5 μm and not more than 6.5 μm.
The glass yarn is a bundle of 220 or more glass yarns, and the average yarn width of the glass yarn is 155 μm or more and 195 μm or less.
The method for producing the glass cloth according to any one of claims 1 to 4. The weft yarn is made of 180 glass filaments having an average diameter of more than 6.5 μm and not more than 7.5 μm.
The glass yarn is a bundle of 220 or more glass yarns, and the average yarn width of the glass yarn is 180 μm or more and 220 μm or less.
The method for producing the glass cloth according to any one of claims 1 to 4. The elastic modulus of the glass yarn is 50 to 70 GPa;
The method for producing the glass cloth according to any one of claims 1 to 8. The elastic modulus of the glass yarn is 50 to 63 GPa;
The method for producing glass cloth according to claim 9. The glass cloth has a dielectric constant of 5.0 or less at a frequency of 1 GHz.
The method for producing a glass cloth according to any one of claims 1 to 10. The glass yarn,
The Si content is 40 to 60 mass% in terms of _SiO2 ,
The B content is 15 to ₃₀ mass% calculated as _B2O3 .
The method for producing a glass cloth according to any one of claims 1 to 11. The density is 2.2 g/ ^cm3 or more and less than 2.5 g/ ^cm3 ,
The yarn width distribution coefficient indicating the yarn width variation is 0.003 or more and 0.013 or less, and/or
The yarn width distribution variation coefficient A, which indicates the distribution variation of the yarn width, is 0.0002 or more and 0.0015 or less;
Glass thread.
Yarn width dispersion coefficient = Value obtained by dividing the standard deviation of the yarn width (yarn width standard deviation A) by the average diameter of the glass filaments. Yarn width distribution variation coefficient A = Value obtained by dividing the standard deviation of the yarn width standard deviation B (yarn width distribution standard deviation) when the standard deviation of the yarn width (yarn width standard deviation B) is calculated for every 0.5 m length, by the diameter of the glass filaments constituting the weft. The density of the glass yarn is more than 2.2 g/ ^cm3 and less than 2.5 g/ ^cm3 ;
The yarn width dispersion coefficient is greater than 0.003 and less than 0.010;
And/or, the yarn width distribution variation coefficient A is more than 0.0003 and less than 0.0012;
The glass thread according to claim 13. The yarn width distribution coefficient is 0.005 or more and 0.013 or less,
The yarn width distribution variation coefficient A is 0.0006 or more and 0.0015 or less,
And/or, the yarn width distribution variation coefficient B, which indicates the yarn width distribution variation of the glass yarn that becomes the weft yarn, is 0.013 or more and 0.027 or less;
The glass thread according to claim 13.
Yarn width distribution variation coefficient B = A value obtained by dividing the yarn width distribution CV value, which is obtained by dividing the standard deviation of the yarn width standard deviation B (yarn width distribution standard deviation) by the average value of the yarn width standard deviation B when the yarn width standard deviation B is calculated for each 0.5 m length, by the diameter of the glass filaments constituting the weft yarn. The average number of twists per 25 mm is 0.50 or more and 1.20 or less,
The standard deviation indicating the variation in the number of twists is 0.10 or more and 0.20 or less.
The glass thread according to any one of claims 13 to 15. A glass yarn in which 80 to 120 glass filaments having an average diameter of more than 4.5 μm and not more than 5.5 μm are bundled together, and the average yarn width is 90 μm to 130 μm.
The glass thread according to any one of claims 13 to 16. 180 to 220 glass filaments with an average diameter of 4.5 μm to 5.5 μm
The glass yarn is bundled in a number of strands or less, and the average yarn width is 120 μm or more and 175 μm or less.
The glass thread according to any one of claims 13 to 16. 180 to 220 glass filaments with an average diameter of 5.5 μm to 6.5 μm
The glass yarn is bundled in a number of strands or less, and the average yarn width is 155 μm or more and 195 μm or less.
The glass thread according to any one of claims 13 to 16. 180 to 220 glass filaments with an average diameter of more than 6.5 μm and less than 7.5 μm
The glass yarn is bundled in a number of strands or less, and the average yarn width is 180 μm or more and 220 μm or less.
The glass thread according to any one of claims 13 to 16. The elastic modulus is 50 to 70 GPa.
The glass thread according to any one of claims 13 to 20. The elastic modulus is 50 to 63 GPa.
The glass thread according to any one of claims 13 to 20. having a dielectric constant of 5.0 or less at a frequency of 1 GHz;
The glass thread according to any one of claims 13 to 22. The Si content is 40 to 60 mass% in terms of _SiO2 ,
The B content is 15 to ₃₀ mass% calculated as _B2O3 .
The glass thread according to any one of claims 13 to 23.