JP2019183297A - Glass cloth, prepreg, and printed wiring board - Google Patents

Abstract

To provide a glass cloth restricted in fiber bending while keeping 16 μm or less of a thickness, and a prepreg and a printed wiring board reduced in a signal transmission speed difference of a plurality of transmission lines.SOLUTION: The glass cloth having a thickness of 8 μm or more and 16 μm or less is obtained by weaving glass yarns composed of a plurality of glass filaments as warp and weft, where the existing percentage Y of the weft in a longitudinal direction found by formula (1): Y=F/(25000/G)×100 (1) where F is a yarn width (μm) of the weft, and G is weaving density (line/25 mm) of the weft, is 75% or more and 90% or less, and the sum of a yarn width of the warp and a yarn width of the weft is 380 μm or more and 500 μm or less.SELECTED DRAWING: None

Description

  The present invention relates to a glass cloth, a prepreg, and a printed wiring board.

In many printed wiring boards, a transmission line is formed of a copper foil on an insulator layer composed of a glass cloth and a matrix resin composition.
The glass cloth used for the printed wiring board is formed by plain weaving glass yarn in the warp direction and the weft direction. Therefore, in the insulator layer composed of the glass cloth and the resin composition, the presence ratio of the glass is high at the portion where the yarn crosses, and the presence ratio of the resin is high in the portion where the yarn does not overlap or in the portion where the yarn is not present. Become.
Usually, there is a difference between the dielectric constant of the glass cloth glass and the dielectric constant of the resin composition. Therefore, it is known that there is a difference between the signal propagation speed in the transmission line that passes through the portion where the glass content is high and the signal propagation speed in the transmission line that passes through the portion where the resin composition content is high. It has been. For this reason, in an electronic circuit that needs to synchronize a plurality of signals, there is a possibility that inconvenience may occur in signal processing when a deviation occurs in the arrival time of the signals.

With the recent development of an information communication society, data communication and / or signal processing has been performed at high speed with a large capacity, and the speed of transmitted signals has been increasing. The speed of the signal exceeds 10 Gbps, and the speed increases in the giga region such as 28 Gbps and 56 Gbps. The higher the speed of the signal, the greater the influence of the above signal propagation speed difference, and the reduction in the signal propagation speed difference. There is a growing demand to do so.
Here, when a pair of wires are formed in the same insulator layer, the signal propagation speed transmitted through each wire is a dielectric between the portion where the glass is high and the portion where the resin is high as described above. Since the rates are different, it is known to be affected by the positional relationship between the transmission line and the glass cloth. For this reason, Patent Documents 1 to 3 propose techniques for reducing changes in propagation speed caused by the positional relationship between the glass cloth and the transmission line.
Specifically, Patent Document 1 discloses a technique for setting the line width to 75% to 95% of the distance between the yarns of the glass cloth.
Patent Document 2 discloses a technique for matching the distance between the glass yarns and the distance between the signal lines.
Patent Document 3 discloses a technique for reducing the distance between the glass yarns and the distance between the wiring widths to 50%.

  On the other hand, in order to achieve high functionality, small size, and light weight in recent digital devices, printed wiring boards used are required to be further reduced in size, thickness, and density. As a method for miniaturization, thinning, and densification, it is possible to thin the glass cloth used as a base material and increase the number of layers of the multilayer printed wiring board. Here, the thickness of the glass cloth is required to be reduced to, for example, 16 μm or less in order to achieve high functionality and small size and light weight such as state-of-the-art smartphones and wearable devices. Patent Documents 4 to 6 disclose a glass cloth having a small thickness.

JP, 2014-130860, A International Publication No. 2016/117320 International Publication No. 2017/159649 Japanese Patent No. 3756066 Japanese Patent No. 4446754 Japanese Patent No. 5936726

The glass yarn which comprises a glass cloth has the characteristic which can produce a bend. In particular, a thin glass cloth uses thinner glass yarns than a thick glass cloth. Therefore, the widths of the warps and wefts are generally narrow, and the warp and weft yarns at the intersection of the warp and wefts. Small contact area. For this reason, the mutual binding force between the warp and the weft is weakened. For example, in the manufacturing process of the glass cloth or the process of manufacturing the prepreg using the glass cloth, the parallelism of the rolls conveying the glass cloth is slightly shifted. When there is, a difference in the width direction, that is, the CD direction occurs in the tension acting on the warp. As a result, the warp and the weft intersect with each other at a right angle, but the weft tends to bend or bend.
Also, in the process of manufacturing prepreg, the load is applied to the glass cloth in the width direction in the process of passing through a narrow slit to control the resin adhesion amount when impregnating the resin. , And has a problem that bending is likely to occur.

The bending becomes more conspicuous as the thickness of the glass cloth is reduced and the number of filaments constituting the glass cloth is reduced.
Therefore, as disclosed in Patent Documents 1 to 3, in the method of trying to reduce the signal propagation speed difference by the transmission line considering the arrangement of the glass yarn, the positional relationship between the transmission line and the glass yarn due to the bending of the glass yarn. There is a problem in that it is difficult to precisely control the signal propagation speed.

  The glass cloth specifically disclosed in Examples 1 to 4 of Patent Document 4 has an average value of the amount of bending measured at 10 places for every 10 m of a 100 m long glass cloth, and a thickness of 10 to 10 mm. 12 μm glass cloth. Patent Document 4 discloses that the average value of the amount of bending is small. However, the amount of bending usually varies, so if there is a part with a large amount of bending, a transmission line in which the signal propagation speed fluctuates greatly occurs, and there is a problem in signal processing in an electronic circuit that needs to synchronize multiple signals. Arise.

  The glass cloth specifically disclosed in Examples 1 to 5 of Patent Document 5 is a glass having an average value of the bending amount measured every 10 m of a 100 m long glass cloth and having a thickness of 17 to 21 μm. Cross. In the glass cloth described in Patent Document 5, adjacent yarns are practically arranged without gaps in order to improve small hole workability. Therefore, it is necessary to use glass yarn having a large number of filaments, and it is difficult to reduce the thickness of the glass cloth.

The glass cloth specifically disclosed in the example of Patent Document 6 is a thin glass yarn having a mass of 1.65 × 10 ⁻⁶ kg / m or less for both warp and weft yarn (yarn lighter than BC3000, BC3750, BC5000, BC6000) ) And the warp and weft widths are narrow. Therefore, the mutual restraining force at the intersection of the warp and the weft is weak, and the bending is likely to occur like the conventional glass cloth.

This invention is made | formed in view of the said subject, and it aims at providing the glass cloth by which the bending was suppressed, maintaining thickness at 16 micrometers or less.
Another object of the present invention is to provide a prepreg and a printed wiring board using the glass cloth, in which a difference in signal propagation speed between a plurality of transmission lines is reduced.

As a result of intensive studies to solve the above problems, the inventors of the present invention have a glass cloth that satisfies the ratio of the weft yarn in the longitudinal direction and the sum of the warp yarn width and the weft yarn width within a specific range. The inventors have found that the occurrence of bending is suppressed while maintaining the thickness at 16 μm or less, and have completed the present invention.
Further, the present inventors have a specific ratio of the weft yarn in the longitudinal direction, and the weft yarn bending amount and the weft interval satisfy a specific relationship. When the glass cloth is a printed wiring board, In addition, it has been found that the fluctuation of the signal propagation speed can be reduced because the distance that can suppress the change in the glass presence rate in the insulator layer through which the transmission line arranged parallel to the weft passes can be reduced. The present invention has been completed.

That is, the present invention is as follows.
[1]
A glass cloth having a thickness of 8 μm or more and 16 μm or less, which is formed by weaving glass yarns composed of a plurality of glass filaments as warps and wefts,
Formula (1);
Y = F / (25000 / G) × 100 (1)
(In the formula, F is the weft yarn width (μm), and G is the weft weave density (lines / 25 mm).)
The ratio Y of the weft yarn in the longitudinal direction, which is obtained in the above, is 75% to 90%,
A glass cloth having a sum of a warp yarn width and a weft yarn width of 380 μm to 500 μm.
[2]
The sum of the elongation in the warp direction that occurs when a load of 5 N per 25 mm width is applied in the warp direction and the elongation in the weft direction that occurs when a load of 5 N per 25 mm width is applied in the weft direction is 0.50% or less The glass cloth according to [1].
[3]
A glass cloth having a thickness of 8 μm or more and 16 μm or less, which is formed by weaving glass yarns composed of a plurality of glass filaments as warps and wefts,
Formula (1);
Y = F / (25000 / G) × 100 (1)
(In the formula, F is the weft yarn width (μm), and G is the weft weave density (lines / 25 mm).)
The ratio Y of the weft yarn in the longitudinal direction, which is obtained in the above, is 75% to 90%,
A glass cloth in which the weft yarn bend amount is equal to or less than a value obtained by dividing 10 times the weft interval (mm) by 500 mm.
[4]
The glass cloth according to [3], wherein the weft yarn bending amount is equal to or less than a value obtained by dividing five times the weft interval (mm) by 500 mm.
[5]
The glass cloth according to [3], wherein the weft yarn bending amount is not more than a value obtained by dividing 2.5 times the weft interval (mm) by 500 mm.
[6]
The glass cloth according to [3], wherein the weft yarn bending amount is equal to or less than a value obtained by dividing 1.0 times the weft interval (mm) by 500 mm.
[7]
The glass cloth according to any one of [3] to [6], wherein the sum of the warp yarn width and the weft yarn width is 380 μm or more and 500 μm or less.
[8]
The sum of the elongation in the warp direction that occurs when a load of 5 N per 25 mm width is applied in the warp direction and the elongation in the weft direction that occurs when a load of 5 N per 25 mm width is applied in the weft direction is 0.50% or less The glass cloth according to [7].
[9]
The glass cloth according to [1] or [2], wherein a ratio between a cross-sectional height in the warp direction and a cross-sectional height in the weft direction is 90% or more and 110% or less.
[10]
The sum of the width of the warp and the width of the weft is 380 μm or more and 500 μm or less,
The glass cloth according to any one of [3] to [6], wherein a ratio between a cross-sectional height in the warp direction and a cross-sectional height in the weft direction is 90% or more and 110% or less.
[11]
The average mass per unit length of the warp is 1.4 × 10 ⁻⁶ kg / m or more and less than 1.8 × 10 ⁻⁶ kg / m,
The average mass per unit length of the weft is 1.8 × 10 ⁻⁶ kg / m or more and 4.0 × 10 ⁻⁶ kg / m or less, and
Any of [1] to [10], wherein the ratio of the average mass per unit length of the weft to the average mass per unit length of the warp (weft / warp ratio) is greater than 1.20 and less than or equal to 1.80. Glass cloth according to crab.
[12]
The average number of filaments of the warp and weft is substantially the same, and
The average filament diameter of the warp is 3.7 μm or more and 4.3 μm or less,
The average filament diameter of the weft is 4.2 μm or more and 5.3 μm or less,
The glass cloth according to any one of [1] to [10], wherein a ratio of an average filament diameter of the weft to an average filament diameter of the warp (weft / warp ratio) is 1.07 to 1.40.
[13]
The average filament diameters of the warp and weft are substantially the same, and
The average number of filaments of the warp is 45 or more and 70 or less,
The average number of filaments of the weft is 55 or more and 80 or less,
The glass cloth according to any one of [1] to [10], wherein a ratio of an average filament number of wefts to an average filament number of warps (weft / warp ratio) is greater than 1.25 and equal to or less than 1.50.
[14]
A prepreg composed of the glass cloth according to any one of [1] to [13] and a matrix resin.
[15]
The prepreg according to [14], wherein a difference between a dielectric constant at 10 GHz of the glass constituting the glass cloth and a dielectric constant at 10 GHz of the cured product of the matrix resin is 3 or less.
[16]
The prepreg according to [14], wherein a difference between a dielectric constant at 10 GHz of the glass constituting the glass cloth and a dielectric constant at 10 GHz of the cured product of the matrix resin is 2 or less.
[17]
The prepreg according to [14], wherein a difference between a dielectric constant at 10 GHz of the glass constituting the glass cloth and a dielectric constant at 10 GHz of the cured product of the matrix resin is 1 or less.
[18]
The printed wiring board produced using the prepreg in any one of [14]-[17].

  ADVANTAGE OF THE INVENTION According to this invention, the glass cloth by which the bending was suppressed can be provided, maintaining thickness at 16 micrometers or less. When the glass cloth of the present invention is used as a printed wiring board, the positional relationship between the glass yarn and the transmission line can be reduced. Further, according to the present invention, it is possible to provide a prepreg and a printed wiring board having a small difference in signal propagation speed between a plurality of transmission lines.

It is a figure which shows the load-elongation curve which is an elongation amount measurement result of a 1017 style glass cloth, ie, a 14-micrometer-thick glass cloth. It is a figure which shows the load-elongation curve of the glass cloth E obtained in Example 5. FIG. It is a schematic diagram which shows the width | variety of the weft and the space | interval of a weft in the glass cloth of this embodiment. It is a schematic diagram which shows one form of the glass cloth of this embodiment, Comprising: It is a figure which shows one of the forms of a weft. It is a schematic diagram which shows one form of the glass cloth of this embodiment, Comprising: It is a figure which shows one of the forms of a weft. It is a schematic diagram which shows one form of the glass cloth of this embodiment, Comprising: It is a figure which shows one of the forms of a weft.

Hereinafter, the embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. However, the present invention is not limited to this, and various modifications are possible without departing from the scope of the present invention. It is.
The dielectric constant in the present embodiment indicates a value when measured in the 10 GHz band by the cavity resonator perturbation method (perturbation method cavity resonator / manufactured by Kanto Electronics Co., Ltd.).

<Glass cloth>
(thickness)
The glass cloth of the present embodiment is a glass cloth having a thickness of 8 μm or more and 16 μm or less formed by weaving glass yarns composed of a plurality of glass filaments as warps and wefts.
When the thickness is 16 μm or less, it is possible to increase the number of layers of the multilayer printed wiring board, and it is possible to increase the density of the transmission line while maintaining the thickness of the multilayer printed wiring board. Although it is preferable that the glass cloth has a small thickness, it is necessary to make the glass thread to be a thin thread by reducing the thickness, and the strength of the glass cloth is likely to be reduced and the glass bends easily. When the thickness is 8 μm or more, the strength of the glass cloth can be maintained and the occurrence of bending can be suppressed.

(Weft occupancy)
In the glass cloth of this embodiment, the ratio of the wefts in the longitudinal direction is 75% or more and 90% or less. The ratio of the wefts in the longitudinal direction is also called the weft occupancy, and is a value Y obtained from the formula (1) and obtained by dividing the weft width by the weft interval.
Y = F / (25000 / G) × 100 (1)
(In the formula, F is the weft yarn width (μm), and G is the weft weave density (lines / 25 mm).)
The width of the weft is an average value obtained by observing a glass cloth sample having a size of 100 mm × 100 mm with a microscope from the surface, obtaining the widths of all the wefts, and dividing the total by the total number of the wefts. At this time, when the yarn width of the weft varies within the sample, the width of the portion having the largest width is set as the yarn width of the weft.

One of the embodiments is a glass cloth having a thickness of 8 μm or more and 16 μm or less formed by weaving glass yarns made of a plurality of glass filaments as warps and wefts,
Formula (1);
Y = F / (25000 / G) × 100 (1)
(In the formula, F is the weft yarn width (μm), and G is the weft weave density (lines / 25 mm).)
The ratio Y of the weft yarn in the longitudinal direction, which is obtained in the above, is 75% or more and 90% or less,
A glass cloth in which the sum of the warp yarn width and the weft yarn width is not less than 380 μm and not more than 500 μm.
The glass cloth is also referred to as a glass cloth P.

(Sum of warp yarn width and weft yarn width)
In the glass cloth P of the present embodiment, the sum of the warp yarn width and the weft yarn width is not less than 380 μm and not more than 500 μm, preferably not less than 380 μm and not more than 480 μm, and more preferably not less than 400 μm and not more than 480 μm.
When the sum of the width of the warp and the width of the weft is 380 μm or more, the contact area between the warp and the weft increases at the intersection of the warp and the weft, the friction area increases, and the mutual binding force Becomes stronger and curving is suppressed.
When the sum of the width of the warp and the width of the weft is 500 μm or less, the mutual binding force between the warp and the weft at the intersection of the warp and the weft does not become too strong, and the warp and the weft are moderately Since there is room for movement, in a thin glass cloth with a thickness of 16 μm or less, when stress is applied, the warp and weft move with the crossing point as the base point to relieve the stress and suppress the generation and breakage of wrinkles.

Further, since the line width generally used for multilayer wiring boards and the like is about 0.1 mm, a transmission line arranged parallel to the weft in a glass cloth having a weft occupation ratio of 75% to 90%. In order to suppress the change in the abundance ratio of the insulating layer glass through which the yarn passes, the weft yarn width is preferably 300 μm or less, so the sum of the warp yarn width and the weft yarn width is 500 μm or less. It is preferable.
When the sum of the warp yarn width and the weft yarn width is not less than 380 μm and not more than 500 μm, a glass cloth having no wrinkles or bends and excellent handleability can be obtained.

(Sum of elongation)
The glass cloth of this embodiment has an elongation rate in the warp direction that occurs when a load of 5 N per 25 mm width is applied in the warp direction, and an elongation rate in the weft direction that occurs when a load of 5 N per 25 mm width is applied in the weft direction. The sum is preferably 0.50% or less.
The sum of elongation is more preferably 0.48 or less, and still more preferably 0.45 or less.
Here, the elongation percentage of the glass cloth is a value obtained as follows.

The amount of elongation when tension is applied to the glass cloth in the warp direction or the weft direction is measured by applying the method described in JIS R3420, General Test Method for Glass Testing, 7.4 Tensile Strength. According to the method defined by JIS, a test piece having a width of about 30 mm and a length of about 250 mm is taken from the warp direction and the weft direction of the woven fabric, the threads at both ends of the test piece are loosened to a width of about 25 mm, and a gripping piece of about 150 mm is obtained. Secure the gap and attach it to the grip, pull at a pulling speed of about 200 mm / min, and determine the load at break. In this embodiment, in order to improve the measurement accuracy, the tensile test is performed under the same conditions as in the above JIS standard except that the tensile speed is about 10 mm / min and the width of the specimen to be collected is about 35 mm. Then, the amount of displacement when the load per 25 mm width of the glass cloth acts 5N is obtained, and the value obtained using the following equation (2) is defined as “elongation rate of glass cloth”.
Elongation rate = {(interval at load-interval at no load) / interval at no load} × 100 (2)

  As a result of examining the relationship between the fabric structure of glass cloth and the likelihood of bending, the present inventors have found that the "elongation amount of the initial deformation region" when tensile tension acts and the ease of occurrence of bending. It has been found that there is a correlation between them, and when the “elongation amount of the initial deformation region” is made smaller than a specific range, the occurrence of bending is remarkably suppressed in the handling of a normal glass cloth.

FIG. 1 shows a load-elongation curve as a result of measuring the elongation of 1017 style glass cloth having a thickness of 14 μm, which is often used for a printed wiring board as a conventional thin glass cloth.
The load-elongation curve of 1017 style glass cloth is characterized in that the amount of weft elongation is larger than that of warp, and the slope is low until the displacement is about 0-0.2%, and then gradually increases to about 0.4%. Thus, after 0.4%, it swings up upward and has a constant slope.
In the low slope region, there is a gap between the weft and the warp at the intersection of the weft and the warp, and the two are not in a sufficiently close contact with each other. It is reflected that it is pulled greatly until. The region in which the next inclination gradually increases is a region in which the weft crimp unwinding is progressing with an increase in warp crimp. Thereafter, the region where the swing is increased and the inclination is constant is a region where the elastic deformation in which the weft itself extends is occurring.

As described above, the weft yarn of 1017 cross has an initial deformation region before elastic deformation within a very weak tensile tension range of up to 5N per 25 mm, and the elongation amount of the initial deformation region is large.
Compared to a conventional glass cloth such as the 1017 style, the glass cloth of this embodiment has a small amount of elongation in the initial deformation region. FIG. 2 shows a load-elongation curve of the glass cloth E obtained in Example 5. The glass cloth E of the present invention has a small amount of elongation up to 5N in the weft direction, and the amount of elongation in the initial deformation region is kept small. This suggests that the mutual binding force between the warp and the weft is strong at the intersection of the warp and the weft.
Thin glass cloths, especially glass cloths with a thickness of 16 μm or less, are usually thin glass yarns with a filament diameter of 4.0 μm or less and a filament count of 50 or less in order to express the thickness. The mutual restraining force at the intersection of the warp and the weft is weak, and it is easy to bend. However, when the sum of the elongation percentage in the glass cloth is 0.50% or less, the mutual restraint at the intersection of the warp and the weft It tends to be a glass cloth in which the strength is increased and the occurrence of bending is suppressed.

As described above, the sum of the elongation rate in the weft direction that occurs when a load of 5 N per 25 mm width is applied in the weft direction and the elongation rate in the warp direction that occurs when a load of 5 N per 25 mm width is applied in the warp direction is 0. By setting it to 50% or less, the mutual binding force at the intersection of the warp and the weft becomes high, and a glass cloth that is less likely to bend can be obtained.
On the other hand, the lower limit of the sum of elongation is preferably 0.30% or more, more preferably 0.33% or more, and still more preferably 0.35% or more. When the sum of elongation is 0.30% or more, the glass cloth having a woven structure is reversible due to the application of the glass cloth and the structure of the glass cloth is based on the intersection of warp and weft. It tends to be relaxed by changing to, and the generation and breakage of wrinkles tend to be suppressed.
When the sum of the elongation percentages is in the range of 0.30% or more and 0.50% or less, there is a tendency to obtain a glass cloth that is free from wrinkles and bends and has excellent handleability.

One of the embodiments is a glass cloth having a thickness of 8 μm or more and 16 μm or less formed by weaving a glass yarn composed of a plurality of glass filaments as a warp and a weft.
Formula (1);
Y = F / (25000 / G) × 100 (1)
(In the formula, F is the weft yarn width (μm), and G is the weft weave density (lines / 25 mm).)
The ratio Y of the weft yarn in the longitudinal direction, which is obtained in the above, is 75% to 90%,
It is a glass cloth in which the amount of bends in the weft is equal to or less than a value obtained by dividing 10 times the interval between wefts by 500 mm.
The glass cloth is also referred to as a glass cloth Q.

  The weft yarn bending amount is preferably not more than a value obtained by dividing five times the weft interval by 500 mm, more preferably not more than a value obtained by dividing 2.5 times the weft interval by 500 mm. More preferably, it is not more than a value obtained by dividing 1.0 times the weft interval by 500 mm. Here, the unit of “weft spacing” in “value obtained by dividing a value of 10 times, 5 times, 2.5 times, or 1.0 times the weft spacing by 500 mm” is mm.

The weft occupancy and the amount of bend are preferably 77% or more and 87% or less, and the amount of bend is less than or equal to the value obtained by dividing 5 times the weft interval by 500 mm, and the occupancy is 79. It is more preferable that the bend amount is not more than a value obtained by dividing 2.5 times the weft interval by 500 mm, the occupancy is 80% to 84%, and the bend amount is 1. More preferably, it is not more than a value obtained by dividing a value of 0 times by 500 mm.
The interval between the wefts in the present embodiment is the interval between the wefts constituting the glass cloth, and the weft interval in this specification includes the yarn width itself. FIG. 3 is a schematic diagram showing the distance between the wefts in the glass cloth. a is the yarn width, and b is the weft interval.
In addition, the weft interval is obtained from the weft density G (lines / 25 mm) of the weft. Specifically, the weft interval is calculated from 25 / G (mm) when the unit of the interval is mm. When the unit of the interval is μm, it can be calculated from 25000 / G (μm).

  The weft occupancy is 75% or more and 90%, and the bend amount is less than the value obtained by dividing 10 times the weft interval by 500 mm. Since the change in the abundance ratio of the glass in the insulator layer through which the transmission line arranged as described above passes is suppressed to be small, fluctuations in the signal propagation speed tend to be reduced.

Here, when the weft occupancy is 75% or more and 90%, if the amount of bend is equal to or less than the value obtained by dividing 10 times the weft interval by 500 mm, the transmission arranged so as to be parallel to the weft Minimize the deviation between the line and the weft, specifically, the deviation of the transmission line from the weft is kept to a range smaller than 0.5 times the distance between the wefts, and the ratio of glass around the transmission line is the same. It is possible to lengthen the transmission path that can be maintained.
It is preferable that the turning amount is small, and the turning amount is ideally 0, but it may be more than 0.

The “bending amount” in the specification of the present application means a maximum value among Z _N (Z ₀ , Z ₁ , and Z ₂ ) defined by the following formula (I).

Z _N = | (Y _{N + 1} −Y _N ) / (X _{N + 1} −X _N ) | (I)
(Wherein, N represents a 0-2, when the value of X _N + 1 -X _N is 0 is assumed in Z _N is 0)

In the formula, X _{0 to} X ₃ and Y _{0 to} Y ₃ are combinations of (X ₀ , Y ₀ ), (X ₁ , Y ₁ ), (X ₂ , Y ₂ ), and (X ₃ , Y ₃ ). And is defined as follows.
A glass cloth consisting of a plurality of warps and a plurality of wefts, or a prepreg, or a printed wiring board is a sample to be tested, the warp direction of the sample to be tested is the Y direction, and the direction perpendicular to the Y direction is the X direction, Of the first and second warps at both ends of the sample to be tested, with respect to the weft extending from the first warp to the second warp, the contact point between the first warp and the weft is the origin (0, 0), That is, a Y axis and an X axis are defined as (X ₀ , Y ₀ ). Further, the contact point between the second warp and the weft is defined as the end point (X ₃ , Y ₃ ), and one of the points having the maximum value and the minimum value with respect to the coordinate Y of the weft on the X axis and the Y axis is (X ₁ , Y ₁ ) and the other one as (X ₂ , Y ₂ ). In this case, (X ₀ , Y ₀ ), (X ₁ , Y ₁ ), (X ₂ , Y ₂ ) , And (X ₃ , Y ₃ ) are arranged in this order.

Hereinafter, with reference to FIG. 4 to FIG. 6, the calculation method of Z ₀ , Z ₁ , and Z ₂ is exemplarily shown. 4 to 6 are schematic views showing one form of the weft. The form of the weft in the present embodiment is not limited to the form of the weft shown in FIGS.

In FIG. 4, on the weft, the origin (X ₀ , Y ₀ ), the point taking the maximum value of Y (X ₁ , Y ₁ ), the point taking the minimum value of Y (X ₂ , Y ₂ ), and the end point ( X ₃ , Y ₃ ) are arranged in this order. Z ₀ is calculated by substituting two adjacent points (X ₀ , Y ₀ ) and (X ₁ , Y ₁ ) into the above formula (I), and Z ₁ is calculated based on two adjacent points (X ₁ , Y ₁ ) and (X ₂ , Y ₂ ) by substituting into the above formula (I), Z ₂ is calculated as _two adjacent points (X ₂ , Y ₂ ) and (X ₃ , Y _3). ) Is substituted into the above formula (I).

In FIG. 5, on the weft, the origin (X ₀ , Y ₀ ), the point taking the maximum value of Y (X ₁ , Y ₁ ), the point taking the minimum value of Y (X ₂ , Y ₂ ), and the end point ( X ₃ , Y ₃ ) are arranged in this order, where (X ₂ , Y ₂ ) and (X ₃ , Y ₃ ) indicate the same coordinates. Z ₀ , Z ₁ , and Z ₂ can be calculated in the same manner as described above with reference to FIG.
Since (X ₂ , Y ₂ ) and (X ₃ , Y ₃ ) indicate the same coordinates, Z ₂ takes a value of 0 with respect to the above formula (I).

In FIG. 6, on the weft, the origin (X ₀ , Y ₀ ), the point taking the maximum value of Y (X ₁ , Y ₁ ), the point taking the minimum value of Y (X ₂ , Y ₂ ), and the end point ( X ₃ , Y ₃ ) are arranged in this order, where (X ₀ , Y ₀ ) and (X ₁ , Y ₁ ) indicate the same coordinates, and (X ₂ , Y ₂ ) and (X ₃ , Y ₃ ) indicate the same coordinates, and Z ₀ , Z ₁ , and Z ₂ can be calculated in the same manner as described above with reference to FIG.
Since (X ₀ , Y ₀ ) and (X ₁ , Y ₁ ) indicate the same coordinates, Z ₀ takes a value of 0 with respect to the above formula (I), and Z ₂ is also 0. Takes the value of

  Whereas the amount of curvature described in the examples of Patent Documents 4 and 5 is an average value measured at several points, in the present embodiment, the maximum value is the amount of curvature in the present embodiment. This is because in an electronic circuit that needs to synchronize a plurality of signals, there is a possibility of inconvenience in signal processing due to even a single difference in arrival time of signals.

In the glass cloth Q of the present embodiment, the sum of the warp yarn width and the weft yarn width is preferably 380 μm or more and 500 μm or less, preferably 380 μm or more and 480 μm or less, more preferably 400 μm or more and 480 μm or less. .
When the sum of the width of the warp and the width of the weft is 380 μm or more, the contact area between the warp and the weft becomes larger at the intersection of the warp and the weft, the mutual binding force becomes stronger, and the bend is bent. Is suppressed.
When the sum of the width of the warp and the width of the weft is 500 μm or less, the mutual binding force between the warp and the weft at the intersection of the warp and the weft does not become too strong, and the warp and the weft are moderately Since there is room for movement, in a thin glass cloth with a thickness of 16 μm or less, when stress is applied, the warp and weft move with the crossing point as the base point to relieve the stress and suppress the generation and breakage of wrinkles.

Further, since the line width generally used for multilayer wiring boards and the like is about 0.1 mm, a transmission line arranged parallel to the weft in a glass cloth having a weft occupation ratio of 75% to 90%. In order to suppress the change in the abundance ratio of the insulating layer glass through which the yarn passes, the weft yarn width is preferably 300 μm or less, so the sum of the warp yarn width and the weft yarn width is 500 μm or less. It is preferable.
When the sum of the warp yarn width and the weft yarn width is not less than 380 μm and not more than 500 μm, a glass cloth having no wrinkles or bends and excellent handleability can be obtained.

  In the glass cloth Q of the present embodiment, the sum of the warp yarn width and the weft yarn width is 380 μm or more and 500 μm or less, and the elongation in the warp direction that occurs when a load of 5 N per 25 mm width is applied in the warp direction. The sum of the elongation in the weft direction that occurs when a load of 5 N per 25 mm width is applied in the weft direction is preferably 0.50% or less.

(Ratio of warp and weft at cross-section height)
In the glass cloth of this embodiment, the ratio of the cross-sectional height in the warp direction to the cross-sectional height in the weft direction is preferably 90% or more and 110% or less.
The ratio between the cross-sectional height in the warp direction and the cross-sectional height in the weft direction is more preferably 92% to 108%, and still more preferably 95% to 105%.
The cross-sectional height in the warp direction is the cross-sectional height of the glass cloth when the cross-sectional image of the glass cloth is observed so that four or more adjacent warps are continuously inserted. Similarly, the cross-sectional height in the weft direction is the cross-sectional height of the glass cloth when the cross-sectional image of the glass cloth is observed so that four or more adjacent wefts continuously enter.
When the ratio of the cross-sectional height in the warp direction to the cross-sectional height in the weft direction is 90% or more and 110% or less, the glass and resin in the Z-axis direction, that is, in the thickness direction, in the portion where the glass yarn of the insulator layer exists. Since the uniformity of the presence of the composition is improved, the fluctuation of the signal propagation speed tends to be reduced.

  In the glass cloth Q of the present embodiment, the sum of the warp yarn width and the weft yarn width is 380 μm or more and 500 μm or less, and the ratio of the cross-sectional height in the warp direction to the cross-sectional height in the weft direction is 90% or more and 110 % Or less is preferable.

(Mass of glass yarn)
In the glass cloth of the present embodiment, the mass per unit length of the warp is 1.40 × 10 ⁻⁶ kg / m or more and less than 1.80 × 10 ⁻⁶ kg / m, and the weight per unit length of the weft is The mass is 1.80 × 10 ⁻⁶ kg / m or more and 4.00 × 10 ⁻⁶ kg / m or less, and the average mass per unit length of the weft relative to the average mass per unit length of the warp The ratio, that is, the ratio of the weft to the warp (weft / warp ratio) is preferably 1.20 or more and 1.80 or less.
The ratios of the weight per unit length of the warp, the weight per unit length of the weft, and the average mass are preferably warp: 1.45 × 10 ⁻⁶ kg / m or more and 1.75 × 10 ⁻ Less than ⁶ kg / m, weft: 1.90 × 10 ⁻⁶ kg / m or more and 3.50 × 10 ⁻⁶ kg / m or less, weft / warp ratio: 1.22 or more and 1.75 or less, even more preferable Are warps; 1.50 × 10 ⁻⁶ kg / m or more and less than 1.70 × 10 ⁻⁶ kg / m, wefts: 2.00 × 10 ⁻⁶ kg / m or more and 3.00 × 10 ⁻⁶ kg / m m or less, weft / warp ratio; 1.23 or more and 1.70 or less.

In the manufacturing process, a physical load is applied to the glass cloth in the process of adjusting the coating amount of the silane agent after the silane treatment agent is impregnated or the fiber opening process. In addition, when prepreg coating is performed using a glass cloth, a physical load is applied to the glass cloth in a process of adjusting and drying the amount of the resin varnish after impregnating the resin varnish. In order to convey stably and continuously without severing the glass cloth in the above process, it is preferable that the warp has a certain strength or more. For this purpose, a glass yarn of 1.40 × 10 ⁻⁶ kg / m or more is used. It is preferable. On the other hand, by using glass yarn having an average weight per unit length of less than 1.80 × 10 ⁻⁶ kg / m as the warp, the thickness can be maintained at 16 μm or less, and the weave density is, for example, 90 or more. There is a tendency that the number of pinholes can be suppressed.

By using a glass yarn having an average mass per unit length of 1.80 × 10 ⁻⁶ kg / m or more as the weft, the stiffness of the weft tends to increase, and the bending tends to be reduced. Although it is preferable that the mass per unit length of the glass yarn used for the weft yarn is excellent in terms of rigidity, in order to keep the thickness of the glass cloth to 16 μm or less, the average mass per unit length is 4.00 × 10 × 10. ^-6 kg / m or less is preferable.

In addition, when the mass ratio of the weft and the warp is 1.20 or more, the difference between the stiffness of the weft and the stiffness of the warp becomes large. Therefore, even when the yarn used for the weft is thin and not rigid, the weft is used in the weaving process. The waviness of the weft can be kept small, and the weft and the weft that intersects the weft can be in close contact with little gap. In addition, the waviness of the weft inserted without any restraining force varies depending on the variation of the line tension acting on the warp in the weaving process, but the rigidity difference between the warp and the weft increases. The fluctuation of the undulation structure can be reduced. Therefore, the fluctuation of the “elongation amount of the initial deformation region” when the tensile tension is applied is small, and a glass cloth having a small bend amount tends to be obtained stably.
Furthermore, the weft waviness is reduced, and the warp waviness is increased. As a result, the crimp amplitude of the weft and the warp approaches, and the crimp amplitude of the warp is 50% or more and 80% or less of the glass cloth thickness, and the weft crimp The amplitude tends to be adjusted in the range of 60% to 90% of the glass cloth thickness.

On the other hand, when the mass ratio of the weft and the warp is 1.80 or less, the difference in rigidity between the warp and the weft is prevented from becoming extremely large, and the undulation structure of the weft is moderately preserved. Since there is no great difference in the undulation structure with the weft, there is a tendency that anisotropy and warpage of the dimensional stability when a printed wiring board is produced due to the difference in rigidity between the warp and the weft.
The ratio of the weight per unit length of the warp, the weight per unit length of the weft, and the ratio of the weight of the weft and the warp is within the above range, so that the anisotropy of dimensional stability when used as a printed wiring board and There is a tendency that the “elongation amount of the initial deformation region” when the tensile tension is applied can be reduced to a specific range while preventing warping.

(Average filament diameter, average number of filaments)
In the glass cloth of this embodiment, the average filament numbers of the warp and the weft are substantially the same, the average filament diameter of the warp is 3.7 μm or more and 4.3 μm or less, and the average filament diameter of the weft is The ratio of the average filament diameter of the weft to the average filament diameter of the warp (weft / warp ratio) is preferably 1.07 to 1.30.

While the average filament number and average filament diameter of the warp and weft yarns are in the above range, while maintaining the thickness of the glass cloth at 16 μm or less, while preventing anisotropy and warpage of the dimensional stability of the printed wiring board, There is a tendency that the rigidity in the weft direction can be increased and curving can be suppressed.
More preferably, the average filament diameter of the warp and the weft, and the range of the weft / warp ratio of the average filament diameter are respectively warp; 3.8 μm to 4.2 μm, weft; 4.3 μm to 5.2 μm, average filament Weft / warp ratio of diameter: 1.08 or more and 1.25 or less, more preferably warp; 3.9 μm or more and 4.1 μm or less, weft; 4.4 μm or more and 5.1 μm or less, weft of average filament diameter / Warn ratio: 1.09 or more and 1.20 or less.

The average number of filaments of the warp and the weft is substantially the same as the ratio of the number of warp filaments to the number of filaments of the wefts (weft / warp ratio) is in the range of 0.94 to 1.06. Point to. When the weft / warp ratio of the average number of filaments is 0.94 or more and 1.06 or less, the effect of increasing the filament diameter of the weft, that is, the rigidity in the weft direction tends to be excellent.
In this embodiment, when the average number of filaments of the warp and the weft is substantially the same, the number of filaments of the warp and the weft is preferably 60 or less. By setting the number of filaments to 60 or less, the filaments are easily diffused by physical processing in the glass cloth manufacturing process, and the filament distribution in the Z direction of the glass yarn bundle can be reduced, so that the thickness of the glass cloth can be easily reduced. In order to reduce the thickness of the glass cloth, it is preferable that the number of filaments is small. However, from the viewpoint of the strength and handleability of the glass cloth, when the average number of filaments of the warp and the weft is substantially the same, the lower limit of the number of filaments is , Preferably 44 or more, more preferably 46 or more, and still more preferably 48 or more.

In the glass cloth of this embodiment, the average filament diameters of the warp and the weft are substantially the same, the average number of filaments of the warp is 43 or more and 70 or less, and the average number of filaments of the weft is 55. The ratio of the average number of filaments of the warp to the average number of filaments of the warp (weft / warp ratio) is preferably greater than 1.25 and less than or equal to 1.50.
By maintaining the average number of filaments of warp and weft and the average filament diameter in the above-mentioned range, while maintaining the thickness of the glass cloth at 16 μm or less, while preventing the dimensional stability anisotropy and warpage of the printed wiring board , There is a tendency that the rigidity in the weft direction can be increased and curving can be suppressed.
The average number of filaments of the warp and the weft and the range of the ratio (weft / warp ratio) are more preferably the warp: 43 to 65, the weft; 57 to 75, the average filament number of weft / Warp ratio: 1.27 or more and 1.45 or less, and more preferably warp threads: 45 or more and 60 or less, wefts: 60 or more and 70 or less, average filament weft / warp ratio; 1.30 or more and 1 .40 or less.

The average filament diameter of the warp and the weft is substantially the same means that the ratio of the filament diameter of the warp to the filament diameter of the weft (weft / warp ratio) is in the range of 0.95 to 1.05. . When the average filament diameter weft / warp ratio is in the range of 0.95 to 1.05, the effect of increasing the number of filaments in the weft, that is, the rigidity in the weft direction tends to be excellent.
In this embodiment, when the average filament diameters of the warp and the weft are substantially the same, the filament diameters of the warp and the weft are preferably 3.8 μm or more. When the average filament diameter of the warp and the weft is 3.8 μm or more, the rigidity of the glass cloth tends to be increased. In order to increase the rigidity of the glass cloth, a larger filament diameter is preferable. However, from the viewpoint of the thickness of the glass cloth, when the average filament diameter of the warp and the weft is substantially the same, the average filament diameter of the warp and the weft An upper limit becomes like this. Preferably it is 4.4 micrometers or less, More preferably, it is 4.3 micrometers or less, More preferably, it is 4.2 micrometers or less.

The glass yarn constituting the glass cloth of the present embodiment is not particularly limited, and E glass (non-alkali glass) generally used for printed wiring board applications may be used, or D glass, Low dielectric constant glass such as L glass, NE glass and silica glass (Q glass), high strength glass such as S glass and T glass, and high dielectric constant glass such as H glass may be used.
By using glass fiber yarns having a dielectric constant close to that of the resin to be impregnated as warps and wefts, the nonuniformity of the dielectric constant tends to be further reduced. The dielectric constant of the glass cloth is preferably 5.0 or less, more preferably 4.5 or less, from the viewpoint of reducing the nonuniformity of the dielectric constant.

  The woven structure of the glass cloth is not particularly limited, and examples thereof include woven structures such as plain weave, Nanako weave, satin weave, and twill weave. Furthermore, a mixed woven structure using different types of glass yarn may be used. Among these, a plain weave structure is preferable.

  In addition, the glass cloth of a laminated board used for a printed wiring board or the like is usually subjected to a surface treatment with a treatment liquid containing a silane coupling agent. As the silane coupling agent, a commonly used silane coupling is used. An agent, an acid, a dye, a pigment, a surfactant and the like may be added as necessary.

As the silane coupling agent, for example, a silane coupling agent represented by the formula (2) is preferably used.
X (R) _3-n SiY _n (2)
In formula (2), X is an organic functional group having at least one of an amino group and an unsaturated double bond group, Y is each independently an alkoxy group, and n is 1 or more and 3 R is the following integer, 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 of an amino group and an unsaturated double bond group, and X is an organic functional group having at least four of an amino group and an unsaturated double bond group. A functional group is more preferable.
Any form can be used as the alkoxy group, but an alkoxy group having 5 or less carbon atoms is preferable from the viewpoint of stabilizing the glass cloth.

  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 (vinyl) Benzyl) aminoethyl) -N-γ- (N-vinylbenzyl) -γ-aminopropyltrimethoxysilane and its hydrochloride, N-β- (N-benzylaminoethyl) -γ-aminopropyltrimethoxysilane and its Hydrochloride, N-β- (N-benzylaminoethyl) -γ-aminopropyltriethoxysilane and its hydrochloride, γ- (2-aminoethyl) E) aminopropyltrimethoxysilane, γ- (2-aminoethyl) aminopropyltriethoxysilane, aminopropyltrimethoxysilane, vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, etc. These may be used alone or as a mixture thereof.

  The molecular weight of the silane coupling agent is preferably 100 to 600, more preferably 150 to 500, and still 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 glass yarn surface with two or more types of silane coupling agents having different molecular weights, the treatment agent density on the glass surface is increased, and the reactivity with the matrix resin tends to be further improved.

The ignition loss value of the glass cloth is preferably 0.10% by mass or more and 2.00% by mass or less, more preferably 0.12% by mass or more and 1.50% by mass or less, and still more preferably 0.15% by mass. It is at least 1.20% by mass. The ignition loss value of the glass cloth is an index for indirectly evaluating the surface treatment amount of the glass cloth with the silane coupling agent.
When the ignition loss value is 0.10% by mass or more, the glass cloth is uniformly surface-treated with the silane coupling agent, and the texture of the glass cloth becomes hard and is difficult to bend. When the remaining amount of ignition is 2.00% or less, the texture of the glass cloth is kept moderately soft, and it is preferable that wrinkles are difficult to enter. The ignition loss value of the glass cloth is a value obtained according to the method described in JIS R 3420.

<Method for producing glass cloth>
The method for producing the glass cloth of the present embodiment is not particularly limited. For example, the surface of the glass filament is almost completely covered with the treatment liquid having a silane coupling agent concentration of 0.1 to 3.0 wt%. A method having a covering step of covering with, a fixing step of fixing the silane coupling agent to the surface of the glass filament by heat drying, and a fiber opening step of opening the glass yarn of the glass cloth are preferably mentioned.

  As the solvent for dissolving or dispersing the silane coupling agent, either water or an organic solvent can be used, but water is preferably used as the main solvent from the viewpoint of safety and protection of the global environment. As a method for obtaining a treatment liquid containing water as a main solvent, a method in which a silane coupling agent is directly added to water, an organic solvent solution is prepared by dissolving the silane coupling agent in a water-soluble organic solvent, and then the organic solvent solution is used. Any one of the methods of putting in water is preferable. In order to improve the water dispersibility and stability of the silane coupling agent in the treatment liquid, a surfactant may be used in combination.

  As a method of applying the silane coupling agent treatment liquid to the glass cloth, (a) a method of storing the treatment liquid in a bath and immersing and passing the glass cloth, (b) treatment with a roll coater, a die coater, or a gravure coater The method etc. which apply | coat a liquid directly to glass cloth are mentioned. When applying by the above method (a), it is preferable to select an immersion time of the glass cloth in the treatment liquid of 0.5 second or more and 1 minute or less.

Moreover, after apply | coating a silane coupling agent process liquid to glass cloth, well-known methods, such as a hot air and electromagnetic waves, are mentioned as a method of heating and drying a solvent.
The heating and drying temperature is preferably 90 ° C. or higher, and more preferably 100 ° C. or higher so that the reaction between the silane coupling agent and glass is sufficiently performed. Moreover, in order to prevent deterioration of the organic functional group which a silane coupling agent has, heat drying temperature becomes like this. Preferably it is 300 degrees C or less, More preferably, it is 200 degrees C or less.

In addition, the opening method in the opening step is not particularly limited, and examples thereof include a method of opening a glass cloth with spray water (high-pressure water opening), vibrowasher, ultrasonic water, mangle and the like. . In order to keep the total area of the basket hole in a certain range, it is preferable to perform the opening process with spray water.
In the case of opening with spray water, the water pressure may be set as appropriate, and the water pressure is preferably constant in order to adjust the total area of the basket holes present in the glass cloth. Here, making the water pressure constant means reducing the difference between the water pressure of the spray set for carrying out the fiber opening and the maximum value and the minimum value of the actual water pressure. You may have the process of heat-drying also before and after the opening process.

<Prepreg>
One of the embodiments is a prepreg composed of the glass cloth and the matrix resin described in the present embodiment. The prepreg of the present embodiment is a thin prepreg with little bending, and can be preferably used as a prepreg for a printed wiring board.
Here, the difference in dielectric constant between the glass cloth and the matrix resin is preferably 3.0 or less, more preferably 2.0 or less, and even more preferably 1.0 or less. The smaller the difference in dielectric constant, the better. The lower limit of the dielectric constant may be 0 or more. By reducing the difference in dielectric constant between the glass cloth and the cured resin, the nonuniformity of the dielectric constant can be reduced even when the glass and resin abundance in the insulator layer varies. Tend to reduce fluctuations in the signal propagation speed.

The prepreg using the glass cloth of this embodiment can be produced according to a conventional method. As a method for producing the prepreg of the present embodiment, for example, the glass cloth of the present embodiment is impregnated with a varnish obtained by diluting a matrix resin such as an epoxy resin with an organic solvent, and then the organic solvent is volatilized in a drying furnace. And a method of obtaining a resin-impregnated prepreg by curing the thermosetting resin to a B-stage state, that is, a semi-cured state.
As the matrix resin, in addition to the above-mentioned epoxy resin, thermosetting of bismaleimide resin, cyanate ester resin, unsaturated polyester resin, polyimide resin, bismaleimide triazine resin (also called BT resin), functionalized polyphenylene ether resin, etc. Resin, thermoplastic resin such as polyphenylene ether resin, polyetherimide resin, fully aromatic polyester liquid crystal polymer (also referred to as LCP), polybutadiene, fluorine resin; or a mixed resin thereof. From the viewpoint of improving dielectric properties, heat resistance, solvent resistance, and press moldability, a resin obtained by modifying a thermoplastic resin with a thermosetting resin may be used.

  In addition, the matrix resin includes an inorganic filler such as silica and aluminum hydroxide, a flame retardant such as bromine, phosphorus and metal hydroxide, other silane coupling agents, heat stabilizers, antistatic agents, A resin in which an ultraviolet absorber, a pigment, a colorant, a lubricant and the like are mixed may be used.

<Printed wiring board>
One of the embodiments is a printed wiring board composed of the glass cloth and the matrix resin of the embodiment. The printed wiring board of the present embodiment can be a printed wiring board in which the positional relationship between the glass yarn and the transmission line is small in the printed wiring board and the difference in signal propagation speed between the plurality of transmission lines is small.
Here, the difference in dielectric constant between the glass cloth and the matrix resin is preferably 3.0 or less, more preferably 2.0 or less, and even more preferably 1.0 or less. The smaller the difference in dielectric constant, the better. The lower limit value of the dielectric constant may be 0 or more. By reducing the difference in dielectric constant between the glass cloth and the cured resin, even if there is a variation in the abundance of glass and resin composition in the insulator layer, the non-uniformity of the dielectric constant is reduced. Therefore, the variation in the signal propagation speed tends to be reduced.

  The printed wiring board of this embodiment can be manufactured according to a conventional method. For example, a step of laminating a single or plural prepregs of the present embodiment, attaching a copper foil on both surfaces of the obtained laminated plate, heating and pressurizing, and producing a cured copper-clad laminate, the copper-clad laminate A double-sided printed wiring board can be manufactured through a step of producing a circuit pattern made of copper foil on both sides of the board, and then a step of forming a through hole and ensuring electrical connection between the circuit patterns on both sides.

Hereinafter, the present invention will be described specifically by way of examples.
The physical properties of the glass cloth in the examples and comparative examples were measured according to JIS R3420.
The elongation in the warp direction and the elongation in the weft direction of the glass cloth were measured according to a method based on JIS 3420.
Further, the amount of bending of the glass cloth was measured according to the above-described method based on JIS L1096.

<Example 1>
An average filament diameter of 4.0 μm for warp yarn, 50 filaments, 1.0 Z twist, weight of E glass of 1.65 × 10 ⁻⁶ kg / m per unit length, and an average filament diameter of 4.5 μm for weft , 50 filaments, 1.0Z twist, 2.07 × 10 ^-6 kg / m E-glass yarn per unit length, air jet loom, 93.5 warps / 25mm A glass cloth was woven at a weaving density of 70 wefts / 25 mm. The resulting green glass cloth was heat-treated at 400 ° C. for 24 hours to remove glue. Next, the glass cloth was immersed in a treatment solution using N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane; SZ6032 (manufactured by Dow Corning Toray), which is a silane coupling agent. After the squeezing, it was dried at 120 ° C. for 1 minute and further opened by high-pressure water spray to obtain a glass cloth A having a weight of 12.1 and a thickness of 13 μm.
The widths of the warp and weft of the glass cloth A are 139 μm and 285 μm, respectively, the weft occupation ratio is 80%, the elongation in the warp direction is 0.20%, the elongation in the weft direction is 0.27%, and the cross section in the warp direction. The ratio of the height to the cross-sectional height in the weft direction was 0.97. The amount of bending of the glass cloth A was 3 mm, and the glass cloth was excellent in handleability.
Glass cloth A was processed into a width of 650 mm for a coating test, and prepreg coating was performed using an epoxy resin varnish. The epoxy resin varnish comprises 80 parts by mass of a low brominated bisphenol A type epoxy resin, 20 parts by mass of a cresol novolac type epoxy resin, 2 parts by mass of dicyandiamide, 0.2 parts by mass of 2-ethyl-4-methylimidazole, 2-methoxy -100 mass parts of ethanol was mix | blended and prepared. The glass cloth is conveyed at a speed of 3 m / min, the glass cloth A is immersed in an epoxy resin varnish, and the excess varnish is scraped off through a slit whose gap is adjusted so that the resin content becomes 68% by mass. Drying was performed under the conditions of 170 ° C. and drying time of 1 minute 30 seconds, and the epoxy resin was semi-cured (B-staged) to obtain prepreg A.
The prepreg A was cut to a size of 550 mm × 550 mm, and then a 35 μm thick copper foil was placed on both surfaces of the prepreg A, and then compression molded at 175 ° C. and 40 kgf / cm ² to obtain a substrate A. The obtained substrate A was subjected to an etching process, and was processed so that a copper foil line having a width of 200 μm was arranged at right angles to the warp, whereby an evaluation substrate A was obtained.
The distance between the copper foil wire and the weft was evaluated to be 73 mm as a result of evaluating the distance that the gap between the copper foil wire and the weft was within 0.5 times the spacing of the weft.

<Example 2>
Except for the weft density of 75 yarns / 25 mm, weaving of the glass cloth and the subsequent treatment were performed in the same manner as in Example 1 to obtain a glass cloth B having a weight of 12.5 g / m ² and a thickness of 14 μm. Obtained. The widths of the warp and weft of the glass cloth B are 137 μm and 276 μm, respectively, the weft occupation rate is 83%, the elongation in the warp direction is 0.18%, the elongation in the weft direction is 0.24%, and the cross section in the warp direction. The ratio of the height to the cross-sectional height in the weft direction was 1.00. The amount of bending of the glass cloth B was 2 mm, and the glass cloth was excellent in handleability.
As in Example 1, the evaluation substrate B was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the interval between the wefts was evaluated, and as a result, it was 101 mm.

<Example 3>
Except for the weft density of 78 yarns / 25 mm, weaving of glass cloth and the subsequent treatment were performed in the same manner as in Example 1 to obtain glass cloth C having a weight of 12.7 g / m ² and a thickness of 15 μm. Obtained. The widths of the warp and weft of the glass cloth C are 135 μm and 274 μm, respectively, the weft occupation rate is 85%, the elongation in the warp direction is 0.18%, the elongation in the weft direction is 0.22%, and the cross section in the warp direction. The ratio between the height and the cross-sectional height in the weft direction was 1.03. The amount of bending of the glass cloth C was 1 mm, and the glass cloth was excellent in handleability.
As in Example 1, the evaluation substrate C was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the distance between the wefts was evaluated. As a result, it was 198 mm.

<Example 4>
Glass yarn with an average filament diameter of 4.0 μm, a filament count of 67, a twist of 1.0 Z, and a weight per unit length of 2.20 × 10 ⁻⁶ kg / m is used for the weft, and the weft density of the weft is 68 Glass cloth weaving and subsequent treatment were carried out in the same manner as in Example 4 except that the thickness was set to / 25 mm to obtain a glass cloth D having a weight of 12.4 g / m ² and a thickness of 13 μm. The widths of the warp and weft of the glass cloth D are 149 μm and 285 μm, respectively, the weft occupation ratio is 78%, the elongation in the warp direction is 0.18%, the elongation in the weft direction is 0.26%, and the cross section in the warp direction. The ratio between the height and the cross-sectional height in the weft direction was 1.06. The amount of bending of the glass cloth D was 2.5 mm, and the glass cloth was excellent in handleability.
As in Example 1, the evaluation board D was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the interval between the wefts was evaluated. As a result, it was 97 mm.

<Example 5>
Except that the weaving density of the weft yarn was 72/25 mm, weaving of the glass cloth and the subsequent treatment were performed in the same manner as in Example 4 to obtain a glass cloth E having a weight of 12.8 g / m ² and a thickness of 14 μm. Obtained. The widths of the warp and weft of the glass cloth E are 148 μm and 281 μm, respectively, the weft occupation rate is 81%, the elongation in the warp direction is 0.19%, the elongation in the weft direction is 0.25%, and the cross section in the warp direction The ratio between the height and the cross-sectional height in the weft direction was 1.03. The amount of bending of the glass cloth E was 2.0 mm, and the glass cloth was excellent in handleability.
As in Example 1, the evaluation board E was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the distance between the wefts was evaluated. As a result, it was 107 mm.

<Example 6>
Except for the weft density of 75 yarns / 25 mm, weaving of glass cloth and the subsequent treatment were performed in the same manner as in Example 4 to obtain glass cloth F having a weight of 13.3 g / m ² and a thickness of 14 μm. Obtained. The widths of the warp and weft of the glass cloth F are 147 μm and 280 μm, respectively, the weft occupation ratio is 84%, the elongation in the warp direction is 0.18%, the elongation in the weft direction is 0.23%, and the cross section in the warp direction. The ratio between the height and the cross-sectional height in the weft direction was 1.03. The amount of bending of the glass cloth F was 0.5 mm, and the glass cloth was excellent in handleability.
As in Example 1, an evaluation board F was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the distance between the wefts was evaluated, and the result was 412 mm.

<Example 7>
An average filament diameter of 4.0 μm for warp yarn, 50 filaments, 1.0 Z twist, L glass yarn of 1.46 × 10 ⁻⁶ kg / m per unit length, and an average filament diameter of 4.5 μm for weft , L glass yarn with 50 filaments, 1.0Z twist, weight per unit length of 1.95 × 10 ⁻⁶ kg / m, weft density of 93.5 yarns / 25 mm, weft The glass cloth weaving and the subsequent treatment were carried out in the same manner as in Example 1 except that the weaving density was 72 pieces / 25 mm to obtain a glass cloth G having a weight of 11.3 g / m ² and a thickness of 13 μm. It was. The widths of the warp and weft of the glass cloth G are 151 μm and 284 μm, respectively, the weft occupation ratio is 82%, the elongation in the warp direction is 0.18%, the elongation in the weft direction is 0.26%, and the cross section in the warp direction. The ratio between the height and the cross-sectional height in the weft direction was 1.03. The amount of bending of the glass cloth G was 2.0 mm, and the glass cloth was excellent in handleability.
As in Example 1, the evaluation substrate G was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the distance between the wefts was evaluated. As a result, it was 104 mm.

<Comparative Example 1>
For both warp and weft, use an E glass yarn with an average filament diameter of 4.0μm, 50 filaments, 1.0Z twist, and a weight of 1.65 × 10 ^-6 kg / m per unit length. A glass cloth was woven at a weaving density of 93.5 pieces / 25 mm for both warp and weft. The resulting green glass cloth was heat-treated at 400 ° C. for 24 hours to remove glue. Next, the glass cloth was immersed in a treatment solution using N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane; SZ6032 (manufactured by Dow Corning Toray), which is a silane coupling agent. After the squeezing, it was dried at 120 ° C. for 1 minute, and further opened by high-pressure water spray to obtain a glass cloth I having a weight of 12.5 and a thickness of 14 μm.
The widths of the warp and weft of the glass cloth I are 132 μm and 222 μm, respectively, the weft occupation rate is 83%, the elongation in the warp direction is 0.18%, the elongation in the weft direction is 0.36%, and the cross section in the warp direction The ratio of the height to the cross-sectional height in the weft direction was 1.14. The amount of bending of the glass cloth I was 6 mm, and the glass cloth had a large bending.
As in Example 1, the evaluation substrate I was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the interval between the wefts was evaluated. As a result, it was 29 mm.

<Comparative example 2>
An average filament diameter of 4.0 μm for warp yarns, 40 filaments, 1.0 Z twist, E glass yarn of 1.32 × 10 ⁻⁶ kg / m per unit length, and an average filament diameter of 4.0 μm for wefts , 50 filaments, 1.0Z twist, 1.65 × 10 ^-6 kg / m E-glass yarn per unit length, air jet loom, 95 warps and wefts The glass cloth was woven at a woven density of 25 mm. The resulting green glass cloth was heat-treated at 400 ° C. for 24 hours to remove glue. Next, the glass cloth was immersed in a treatment solution using N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane; SZ6032 (manufactured by Dow Corning Toray), which is a silane coupling agent. After the squeezed solution, it was dried at 120 ° C. for 1 minute, and further opened by high-pressure water spray to obtain a glass cloth J having a weight of 10.4 g / m ² and a thickness of 14 μm.
The widths of the warp and weft of the glass cloth J are 123 μm and 213 μm, respectively, the weft occupation rate is 81%, the elongation in the warp direction is 0.28%, the elongation in the weft direction is 0.36%, and the cross section in the warp direction The ratio of the height to the cross-sectional height in the weft direction was 0.97. The amount of bending of the glass cloth J was 8 mm, and the glass cloth had a large bending.
As in Example 1, an evaluation board J was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the distance between the wefts was evaluated. As a result, it was 16 mm.

<Comparative Example 3>
For both warp and weft, use an E glass yarn with an average filament diameter of 4.0μm, 50 filaments, 1.0Z twist, and a weight of 1.65 × 10 ^-6 kg / m per unit length. A glass cloth was woven at a weaving density of 85/25 mm for both warp and weft. The raw glass cloth obtained was subjected to a fiber opening process (processing pressure: 196 N / cm ² ) using a high-pressure water spray under a tension of 4.9 N / m. Thereafter, heat treatment was performed at 400 ° C. for 24 hours to remove the paste. Subsequently, a glass cloth is applied to the treatment liquid using N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane; SZ6032 (manufactured by Dow Corning Toray), which is a silane coupling agent. After dipping and squeezing, the glass cloth K was dried at 120 ° C. for 1 minute to obtain a glass cloth K having a weight of 11.0 g / m ² and a thickness of 12 μm. The chemical and physical treatment of the glass cloth was in accordance with the method of Example 2 of Patent Document 4: Japanese Patent No. 3756066.
The widths of the warp and weft of the glass cloth K are 184 μm and 200 μm, respectively, the weft occupation ratio is 68%, the elongation in the warp direction is 0.26%, the elongation in the weft direction is 0.37%, and the cross-sectional height in the warp direction is The ratio of the cross-sectional height in the weft direction was 1.06. The amount of bending of the glass cloth K was 7 mm, and the glass cloth was large in bending.
As in Example 1, an evaluation substrate K was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the distance between the wefts was evaluated. As a result, it was 21 mm.

<Comparative example 4>
For both the warp and weft, we used an E glass yarn with an average filament diameter of 4.0 μm, 40 filaments, a twist of 1.0 Z, and a weight of 1.32 × 10 ⁻⁶ kg / m per unit length. A glass cloth was woven at a weaving density of 94.5 pieces / 25 mm for both warp and weft. The raw glass cloth obtained was subjected to a fiber opening process (processing pressure: 196 N / cm ² ) using a high-pressure water spray under a tension of 4.9 N / m. Thereafter, heat treatment was performed at 400 ° C. for 24 hours to remove the paste. Subsequently, a glass cloth was dipped in a processing solution using SZ6032 (manufactured by Dow Corning Toray Co., Ltd.) which is a silane coupling agent, and after squeezing, it was dried at 120 ° C. for 1 minute, weight 10.2, thickness An 11 μm glass cloth L was obtained. The chemical and physical treatment of the glass cloth was in accordance with the method of Example 2 of Patent Document 4: Japanese Patent No. 3756066.
The widths of the warp and weft of the glass cloth L are 156 μm and 175 μm, respectively, the weft occupation ratio is 66%, the elongation in the warp direction is 0.16%, the elongation in the weft direction is 0.23%, and the cross section in the warp direction The ratio between the height and the cross-sectional height in the weft direction was 1.09. The amount of bending of the glass cloth L was 7 mm, and the glass cloth was large in bending.
As in Example 1, an evaluation board L was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the distance between the wefts was evaluated.

<Comparative Example 5>
The weft yarn is an E filament with an average filament diameter of 4.5 μm, 50 filaments, a twist of 1.0 Z, and a weight per unit length of 2.07 × 10 ⁻⁶ kg / m. Glass cloth weaving and subsequent treatment were carried out in the same manner as in Comparative Example 1 except that the number was set to 60 pieces / 25 mm to obtain a glass cloth M having a weight of 11.4 g / m ² and a thickness of 12 μm.
The widths of the warp and weft of the glass cloth M are 134 μm and 267 μm, respectively, the occupancy of the weft is 64%, the elongation in the warp direction is 0.21%, the elongation in the weft direction is 0.30%, and the cross section in the warp direction The ratio between the height and the cross-sectional height in the weft direction was 1.09. The amount of bending of the glass cloth M was 5 mm, and the glass cloth had a large bending.
As in Example 1, an evaluation board M was prepared, and the distance between the copper foil wire and the weft was within 0.5 times the distance between the wefts was evaluated, and as a result, it was 41 mm.

  Table 1 shows the characteristics and evaluation results of the glass cloths and substrates produced in the examples and comparative examples.

  The glass cloth of the present invention has industrial applicability as a base material used for printed wiring boards used in the electronic and electrical fields.

a: Thread width of weft b: Interval of weft

Claims (18)

A glass cloth having a thickness of 8 μm or more and 16 μm or less, which is formed by weaving glass yarns composed of a plurality of glass filaments as warps and wefts,
Formula (1);
Y = F / (25000 / G) × 100 (1)
(In the formula, F is the weft yarn width (μm), and G is the weft weave density (lines / 25 mm).)
The ratio Y of the weft yarn in the longitudinal direction, which is obtained in the above, is 75% to 90%,
A glass cloth having a sum of a warp yarn width and a weft yarn width of 380 μm to 500 μm.   The sum of the elongation in the warp direction when a load of 5 N per 25 mm width is applied in the warp direction and the elongation in the weft direction when a load of 5 N per 25 mm width is applied in the weft direction is 0.50% or less The glass cloth according to claim 1, wherein A glass cloth having a thickness of 8 μm or more and 16 μm or less, which is formed by weaving glass yarns composed of a plurality of glass filaments as warps and wefts,
Formula (1);
Y = F / (25000 / G) × 100 (1)
(In the formula, F is the weft yarn width (μm), and G is the weft weave density (lines / 25 mm).)
The ratio Y of the weft yarn in the longitudinal direction, which is obtained in the above, is 75% to 90%,
A glass cloth in which the weft yarn bend amount is equal to or less than a value obtained by dividing 10 times the weft interval (mm) by 500 mm.   The glass cloth according to claim 3, wherein the weft yarn bending amount is equal to or less than a value obtained by dividing five times the weft interval (mm) by 500 mm.   The glass cloth according to claim 3, wherein the weft yarn bending amount is equal to or less than a value obtained by dividing 2.5 times the weft interval (mm) by 500 mm.   The glass cloth according to claim 3, wherein the weft yarn bending amount is equal to or less than a value obtained by dividing a value of 1.0 times the weft interval (mm) by 500 mm.   The glass cloth according to any one of claims 3 to 6, wherein the sum of the warp yarn width and the weft yarn width is 380 µm or more and 500 µm or less.   The sum of the elongation in the warp direction when a load of 5 N per 25 mm width is applied in the warp direction and the elongation in the weft direction when a load of 5 N per 25 mm width is applied in the weft direction is 0.50% or less The glass cloth according to claim 7, wherein   The glass cloth according to claim 1 or 2, wherein a ratio between a cross-sectional height in the warp direction and a cross-sectional height in the weft direction is 90% or more and 110% or less. The sum of the width of the warp and the width of the weft is 380 μm or more and 500 μm or less,
The glass cloth according to any one of claims 3 to 6, wherein a ratio between a cross-sectional height in the warp direction and a cross-sectional height in the weft direction is 90% or more and 110% or less. The average mass per unit length of the warp is 1.4 × 10 ⁻⁶ kg / m or more and less than 1.8 × 10 ⁻⁶ kg / m,
The average mass per unit length of the weft is 1.8 × 10 ⁻⁶ kg / m or more and 4.0 × 10 ⁻⁶ kg / m or less, and
The ratio of the average mass per unit length of weft to the average mass per unit length of warp (weft / warp ratio) is greater than 1.20 and less than or equal to 1.80. The glass cloth according to item. The average number of filaments of the warp and weft is substantially the same, and
The average filament diameter of the warp is 3.7 μm or more and 4.3 μm or less,
The average filament diameter of the weft is 4.2 μm or more and 5.3 μm or less,
The glass cloth according to any one of claims 1 to 10, wherein a ratio of an average filament diameter of the weft to an average filament diameter of the warp (weft / warp ratio) is 1.07 or more and 1.40 or less. The average filament diameters of the warp and weft are substantially the same, and
The average number of filaments of the warp is 45 or more and 70 or less,
The average number of filaments of the weft is 55 or more and 80 or less,
The glass cloth according to any one of claims 1 to 10, wherein a ratio of an average number of weft yarns to an average number of warp yarns (weft / warp ratio) is greater than 1.25 and equal to or less than 1.50.   A prepreg composed of the glass cloth according to any one of claims 1 to 13 and a matrix resin.   The prepreg according to claim 14, wherein a difference between a dielectric constant at 10 GHz of glass constituting the glass cloth and a dielectric constant at 10 GHz of a cured product of the matrix resin is 3 or less.   The prepreg according to claim 14, wherein a difference between a dielectric constant at 10 GHz of glass constituting the glass cloth and a dielectric constant at 10 GHz of a cured product of the matrix resin is 2 or less.   The prepreg according to claim 14, wherein a difference between a dielectric constant at 10 GHz of glass constituting the glass cloth and a dielectric constant at 10 GHz of a cured product of the matrix resin is 1 or less.   The printed wiring board produced using the prepreg as described in any one of Claims 14-17.