TW202233942A - Low dielectric glass cloth, prepreg, and printed wiring board - Google Patents

Abstract

To provide a glass cloth and a glass yarn excellent in insulation reliability, and a prepreg and a printed wiring board which contain the same. A glass cloth includes a glass yarn made of a plurality of glass filaments as warp and weft. The glass filament has a glass composition containing at least one component selected from the group consisting of SiO2, B2O3, and P2O5. The total of the components is 71 pts. mass or more and 100 pts. mass or less relative to 100 pts. mass of the total components of the glass composition. The glass filament has a chrominance value b* of less than 3.9 in CIE L*a*b* color system.

Description

Low dielectric glass cloth, prepreg, and printed circuit board

The present invention relates to a low dielectric glass cloth, a prepreg, a printed circuit board and the like.

With the development of the information and communication society in recent years, data communication and/or signal processing have begun to be performed in large volumes and at high speeds, and there has also been significant progress in lowering the dielectric constant of printed circuit boards used in electronic equipment. Therefore, regarding the glass cloth constituting the printed circuit board, many low-dielectric glass cloths have also been proposed.

For example, the low-dielectric glass cloth disclosed in Patent Document 1 contains a large amount of B ₂ O ₃ in the glass composition compared to the E glass cloth commonly used in the past, and also adjusts the amount of other components such as SiO ₂ . [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2007-262632

[Problems to be Solved by Invention]

If the content ratio of B ₂ O ₃ in the glass yarn is increased in order to lower the dielectric of the glass cloth, the elastic modulus of the glass yarn will decrease, and the glass yarn will be easily cut during the production process. Therefore, as described in Patent Document 1, a coating treatment is performed with a sizing agent (alias: paste) at the time of spinning or warping glass fiber bundles, and after weaving, a treatment called thermal cleaning is performed to remove the glass fiber as adhering to the glass. Sizing agent for the organic matter of fiber bundles.

As described in Patent Document 1, conventional thermal cleaning methods include, for example, a batch-type thermal cleaning method performed at 350 to 500° C., or continuous passage of glass fabrics through a heating furnace at a high temperature of 550 to 700° C. thermal cleaning method. However, the industry knows that if this thermal cleaning method is applied to low-dielectric glass cloth, prepregs with poor insulation reliability will be mixed in the prepregs obtained from the thermally cleaned glass cloths due to combustion residues, etc. .

In view of the above-mentioned problems, an object of the present invention is to provide a glass cloth and glass yarn excellent in insulation reliability, and a prepreg and printed circuit board including the same. [Technical means to solve problems]

As a result of earnest research, the inventors of the present invention found that the above-mentioned problems can be solved by adjusting the hue of a glass cloth having a specific glass composition, thereby completing the present invention.

That is, the present invention is as follows. [1] A glass cloth comprising glass yarns comprising a plurality of glass filaments as warp and weft yarns, wherein the glass filaments include a glass filament selected from the group consisting of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition One or more components in the group, the total of these components is 71 parts by mass to 100 parts by mass relative to 100 parts by mass of the total glass composition, and the glass cloth is in the CIE L ^* a ^* b ^* colorimetric system , the chromaticity coordinate b ^* is less than 3.9. [2] The glass cloth of item [1], wherein the chromaticity coordinate b ^* is b ^* <3.6. [3] The glass cloth of item [1], wherein the chromaticity coordinate b ^* is b ^* <3.3. [4] The glass cloth according to any one of items [1] to [3], wherein the chromaticity coordinate b ^* is greater than 2.0. [5] The glass cloth according to any one of the items [1] to [4], wherein an alkali metal or an alkaline earth metal is attached to the surface of the glass cloth, the alkali metal and the alkaline earth metal are extracted with pure water, and the The chromatograph obtains the total adhesion amount X (mg/m ² ) of alkali metals and alkaline earth metals per unit surface area, and the total adhesion amount X (mg/m ² ) is related to SiO ₂ , B ₂ O ₃ , and The total mass ratio k of P ₂ O ₅ satisfies the following formula: X[mg/m ² ]>(1.5[mg/m ² ])×k. [6] The glass cloth according to item [5], wherein the total adhesion amount X (mg/m ² ) and the total mass ratio k satisfy the following formula: X[mg/m ² ]<(15.0[mg/m ² ]) × k. [7] The glass cloth according to any one of items [1] to [6], wherein the content of alkali metal ions in the glass composition of the glass filaments is less than 0.90 parts by mass relative to 100 parts by mass of the total glass composition. [8] A prepreg comprising: the glass cloth according to any one of the items [1] to [7], and a matrix resin impregnated in the glass cloth. [9] A printed circuit board comprising: the glass cloth according to any one of the items [1] to [7], and a cured product of a matrix resin impregnated in the glass cloth. [10] A glass yarn comprising a plurality of glass filaments, wherein the glass filaments contain one or more components selected from the group consisting of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition, relative to With respect to 100 parts by mass of the total glass composition, the total of these components is 71 parts by mass to 100 parts by mass, and the content of alkali metal ions in the glass composition of the glass strands is less than 0.90 relative to 100 parts by mass of the total glass composition. Part by mass, the total adhesion amount of alkali metal and alkaline earth metal per unit surface area X (mg/m ²⁾ ) and the total mass ratio k of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition satisfies the following formula: X[mg/m ² ]>(1.5[mg/m ² ])×k. [11] The glass yarn according to item [10], wherein the total adhesion amount X (mg/m ² ) and the total mass ratio k satisfy the following formula: X[mg/m ² ]<(15.0[mg/m ² ]) × k. [Effect of invention]

According to the present invention, a glass cloth and a glass yarn having excellent insulation reliability can be provided, and a prepreg or a printed circuit board including the same can also be provided with excellent insulation reliability.

Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail, but the present invention is not limited to this, and various changes can be made without departing from the gist. Furthermore, in this specification, unless otherwise specified, the dielectric constant refers to the dielectric constant at a frequency of 10 GHz.

<Glass cloth> The glass cloth of the present embodiment is constituted by using glass yarns including a plurality of glass filaments as warp and weft yarns, and the glass filaments include a material selected from the group consisting of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition. One or more components in the group, the total of these components is 71 parts by mass to 100 parts by mass relative to 100 parts by mass of the total glass composition, and the glass cloth is in the CIE L ^* a ^* b ^* colorimetric system , the chromaticity coordinate b ^* value is less than 3.9. In addition, it is preferable that the above-mentioned chromaticity coordinate b ^* value is larger than 2.0. Furthermore, the total content of one or more components selected from the group consisting of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition of the glass filaments is preferably 72 parts by mass relative to 100 parts by mass of the total glass composition components. The amount is not less than 90 parts by mass, and more preferably not less than 72.5 parts by mass and not more than 85 parts by mass.

<Hue> In the CIE L ^* a ^* b ^* colorimetric system of the glass cloth of the present embodiment, the chromaticity coordinate b ^* is a value smaller than 3.9, preferably a value larger than 2.0. The L ^* a ^* b ^* colorimetric system was specified by the International Commission on Illumination (CIE) in 1976, and was measured according to JIS Z8781 (2016). In the L ^* a ^* b ^* colorimetric system, the chromaticity coordinate b ^* represents the hue from the blue direction (minimum value: -60) to the yellow direction (maximum value: +60).

According to the present invention, it was found that at least a part of the glass cloth structure excellent in reliability is 2.0<b ^* value<3.9 in the L ^* a ^* b ^* colorimetric system. While not wishing to be bound by theory, the yellowing component in the previous low dielectric glass cloth may prevent the surface treatment of the glass cloth with a silane coupling agent as a subsequent step. However, the glass cloth of 2.0<b ^* <3.9 in the L ^* a ^* b ^* colorimetric system has such a tendency that such yellowing is less, or that the surface treatment can be efficiently performed.

From the viewpoint of further improving reliability, the b ^* value of the L ^* a ^* b ^* colorimetric system of the glass cloth is preferably 3.6 or less, less than 3.6 (b ^* <3.6), 3.3 or less, less than 3.3 (b ^* <3.3), or less than 3.0. Moreover, from a viewpoint of suppressing the fluff of a glass cloth, it is preferable that the lower limit of b ^* value is a value larger than 2.0.

In the CIE L ^* a ^* b ^* colorimetric system of glass cloth, the chromaticity coordinate b ^* can be adjusted to a value less than 3.9 by increasing the temperature or time conditions of the thermal cleaning process described later to suppress yellowing, and/or adhering to the glass cloth described later.

<Glass composition> Hereinafter, the glass composition of the embodiment will be described. Regarding the composition of the glass yarn of the present embodiment, the total mass of silicon (Si) and boron (B) converted into SiO ₂ and B ₂ O ₃ is 70% by mass or more based on the mass of the glass yarn. When the total content of Si and B in terms of SiO ₂ and B ₂ O ₃ is 70% by mass or more, the dielectric constant tends to decrease. Regarding the composition of the glass yarn, from such a viewpoint, the total content of Si and B in terms of SiO ₂ and B ₂ O ₃ is preferably 72.5 mass % or more or 75 mass % or more. The upper limit of the total content of Si and B in terms of SiO ₂ and B ₂ O ₃ may be less than 100 mass %, and/or the Si content may be less than 100 mass % in terms of SiO ₂ .

As long as the total content of Si and B in terms of SiO ₂ and B ₂ O ₃ is 70% by mass or more, the Si content of the glass yarn is preferably 40% by mass or more in terms of SiO ₂ , more preferably 45% by mass or more, 47 mass % or more or 48 mass % or more, and the upper limit may be less than 100 mass % or 99.9 mass % or less.

Silicon (Si) is a component that forms the skeleton structure of the glass yarn, and the strength of the glass yarn is further improved by making the Si content to be 40 _% by mass or more in terms of SiO There is a tendency to further suppress the breakage of the glass cloth in subsequent steps such as the manufacture of the glass cloth. Moreover, there exists a tendency for the dielectric constant of a glass cloth to fall further by making Si content into 40 mass % or more in conversion of _SiO2 .

As long as the total content of Si and B in terms of SiO ₂ and B ₂ O ₃ is 70% by mass or more, the content of B in the glass yarn is preferably 15% by mass to 30% by mass in terms of B ₂ O ₃ , more preferably 17 to 28 mass %, more preferably 17.5 to 25 mass %. By making B content into 15 mass % or more, there exists a tendency for a dielectric constant to fall further. Moreover, by making B content into 30 mass % or less, there exists a tendency for the moisture absorption resistance to improve and insulation reliability to improve further.

In addition, the glass fiber of the present embodiment may contain Fe, F, Al, Ca, Mg, P, Na, K as long as the total content of Si and B in the glass composition is 70% by mass or more in terms of SiO ₂ and B ₂ O ₃ , Ni, Ti, Zn, or a combination of these.

From the viewpoint of electrical properties or strength, the Al content of the glass yarn is preferably 12 to 16 mass % in terms of Al ₂ O ₃ .

The P content of the glass yarn is preferably 0.1% by mass to 6% by mass, more preferably 2.0% by mass to 5.5% by mass, in terms of P ₂ O ₅ . By making P content 0.1 mass % or more in conversion of _P2O5 , there exists a tendency for a dielectric constant to _fall further. In addition, by making the P content to be 6 mass % or less in terms of P ₂ O ₅ , in the fiber opening step or the surface treatment step at the time of glass cloth production, when the glass cloth is passed through a squeeze roll or a nip roll in a wet state, there are some problems. It is not easy to produce the tendency to break. In addition, phase separation at the time of glass fiber production is suppressed, and the moisture absorption resistance of the obtained glass fiber is further improved. Thereby, the obtained printed circuit board is not easily affected by the use environment of the high-humidity environment, and the environmental dependence of the dielectric constant can be reduced.

The Ca content of the glass yarn is preferably 1% by mass to 5% by mass, more preferably 2% by mass to 4% by mass, in terms of CaO. By making the Ca content to be 1 mass % or more in terms of CaO, the viscosity at the time of melting is further reduced in the production process of the glass fiber, and there is a tendency to obtain glass fibers with a more homogeneous glass composition. Moreover, there exists a tendency for a dielectric constant to further improve by making Ca content into 5 mass % or less in conversion of CaO.

The Mg content of the glass yarn is preferably 0.01% by mass to 5% by mass in terms of MgO. By setting the Mg content to 5% by mass or less in terms of MgO, in the fiber opening step or the surface treatment step during glass cloth production, when the glass cloth passes through a squeeze roll or a nip roll in a wet state, it is difficult to break. tendency. In addition, phase separation at the time of glass fiber production is suppressed, and the moisture absorption resistance of the obtained glass fiber is further improved. Thereby, the obtained printed circuit board is not easily affected by the use environment of the high-humidity environment, and the environmental dependence of the dielectric constant can be reduced.

The content of Si, B, Al, P, Ca and Mg can be adjusted according to the amount of raw materials used in the production of glass fiber. In addition, each content described above can be determined by selecting glass yarn from glass cloth and by inductively coupled plasma (ICP) emission spectrometry. In addition, as an ICP emission spectrometer, for example, PS3520VDD II manufactured by Hitachi High-Tech Science can be used.

Specifically, the Si content, the B content, and the total content of Si and B can be obtained by the following methods: after dissolving the weighed glass cloth sample with sodium carbonate, dissolving it with dilute nitric acid and making the volume constant, using ICP emission spectrometry The resulting samples were assayed analytically.

Furthermore, the Al content, the Ca content, and the Mg content can be obtained by the following methods: after heating and decomposing the weighed glass cloth sample with sulfuric acid, nitric acid and hydrogen fluoride, dissolving it with dilute nitric acid and making a constant volume, and analyzing it by ICP emission spectrum The obtained samples were determined by the method.

＜Constitution＞ The glass yarn is obtained by bundling a plurality of glass filaments and twisted as necessary, and the glass cloth is obtained by weaving the above-mentioned glass yarns as warp and weft yarns. Glass yarns are classified as multifilaments and glass filaments are classified as monofilaments.

The average radii of the glass filaments constituting the warp and weft are independent of each other, preferably 2.5 μm to 9 μm, more preferably 3.0 μm to 7.5 μm, and still more preferably 3.5 μm to 5.4 μm. When the average diameter of the glass filaments is within the above-mentioned range, when the obtained substrate is processed with a mechanical drill, a carbon dioxide gas laser, or a UV-YAG laser, the workability tends to be further improved. Therefore, a thin and high-density mounted printed circuit board can be realized. In particular, when the average radius is 5.4 μm or less, the surface area per unit volume increases and hygroscopic viscous matter derived from the sizing agent tends to adhere, so the effect of improving the insulation reliability of the present embodiment becomes more important. In addition, by making the average radius 2.5 μm or more, in the manufacturing process of the glass cloth including the fiber opening step or the surface treatment step, when the glass cloth passes through the squeeze roll or the nip roll in a wet state, there is a tendency that breakage is less likely to occur. . In addition, even in the subsequent steps such as manufacturing a prepreg, when the glass cloth is passed through the slit for the purpose of controlling the resin impregnation amount in the glass cloth, there is a tendency that breakage is less likely to occur.

The weaving density of the warps and wefts constituting the glass cloth is preferably 30/inch to 120/inch, more preferably 40/inch to 110/inch, further preferably 50/inch to 100/inch .

The thickness of the glass cloth is preferably 8 μm to 100 μm, more preferably 10 μm to 70 μm, and still more preferably 12 μm to 50 μm. By making the thickness of the glass cloth within the above-mentioned range, there is a tendency to obtain a thin glass cloth with relatively high strength.

The cloth weight (weight per unit area) of the glass cloth is preferably 8 g/m ² to 250 g/m ² , more preferably 8 g/m ² to 100 g/m ² , and more preferably 8 g/m ² to 8 g/m 2 . 50 g/m ² , particularly preferably 8 g/m ² to 35 g/m ² .

The weave structure of the glass cloth is not particularly limited, and examples thereof include weave structures such as plain weave, square weave, satin weave, and twill weave. Among these, a plain weave structure is more preferable.

<Adhesion treatment> It is preferable that the glass cloth of this embodiment adheres the compound containing an alkali metal or an alkaline earth metal, and it is more preferable that the compound containing an alkali metal or an alkaline earth metal adheres to the surface. In the CIE L ^* a ^* b ^* colorimetric system of glass cloth, the chromaticity coordinate b ^* value can be easily adjusted to less than 3.9 by using the compound containing alkali metal or alkaline earth metal. In addition, in the glass cloth manufacturing process, if the adhesion treatment of the compound containing alkali metal or alkaline earth metal is performed before the desizing (thermal cleaning) step for removing the sizing agent by heating, the yellowing after thermal cleaning can be reduced.

From the viewpoint of improving the reliability of the glass cloth, the alkali metal or alkaline earth metal-containing compound adhering to the glass yarn and the glass cloth preferably contains an alkali metal, and from the viewpoint of further improving the reliability of the glass cloth, it is more preferred to contain sodium (Na).

The Na-containing compound adhering to the glass cloth is not limited, and examples thereof include sodium chloride (NaCl), sodium carbonate (Na ₂ CO ₃ ), and the like.

The alkaline-earth metal-containing compound adhering to the glass cloth preferably contains Mg, and for example, MgCl ₂ and the like can be mentioned, but it is not limited.

The total adhesion amount of alkali metal and alkaline earth metal to glass cloth can be measured by extracting into pure water, for example, by measuring the amount eluted in distilled water. As detection of the elution amount, an ion chromatograph can be mentioned.

From the measured values obtained by the above-mentioned method, the adhered amounts of alkali metals and alkaline earth metals per unit surface area of the glass cloth can be determined. The surface area of the glass cloth is obtained from the diameter of the fibers used and the number of fibers per glass yarn. From the viewpoint of adjusting the b ^* value to an appropriate value, the obtained numerical value X preferably satisfies the following formula including the total mass ratio k of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition . X[mg/m ² ]>(1.5[mg/m ² ])×k The numerical value X is more preferably 2.0×k or more, and still more preferably 2.5×k or more.

Moreover, regarding the above-mentioned formula, it is preferable that the lower limit of the adhesion amount X is less than 15.0×k from the viewpoint of maintaining the breaking strength.

In addition, the numerical value of the said 1.5*k is equivalent to about 0.024 mass part with respect to the following glass cloth, which uses glass type A (described in the following Table 2), and uses 200 fibers, so that the The yarn weaving density is 60/inch, and the weft weaving density is 58/inch.

The degree of yellowing changes according to the ratio of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition, and therefore, the required adhesion amount also changes. While not wishing to be bound by theory, it can be considered to reduce the formulation rate of alkaline earth metals by _increasing the ratio _{of SiO2} , _B2O3 , and _P2O5 in the composition when lowering the dielectric of the glass.

The adhesion treatment is not particularly limited, and examples include a method of weaving a glass cloth after attaching an alkali metal and/or an alkaline earth metal to the glass yarn, or a method of attaching an alkali metal and/or an alkaline earth metal to the woven glass cloth. method. The adhesion method is not limited, but examples include a method of applying an aqueous solution of an alkali metal and/or alkaline earth metal compound to a glass cloth or glass yarn using a two-fluid nozzle, or immersing the glass cloth or glass yarn in the aqueous solution. The method of making it dry, etc.

Moreover, although the method of adding an alkali metal and/or an alkaline earth metal to raw glass can also be considered, from the viewpoint of a dielectric constant and a fracture strength, it is more preferable that an additive component exists only on the surface. Furthermore, although a method of adding an alkali metal and/or an alkaline earth metal to the paste and coating it on the glass yarn can also be considered, it is more preferable that the additive component is present on the surface of the glass cloth from the viewpoint of the effect of the present invention. form.

From the viewpoint of appropriately exhibiting the effects described above, the content of the alkali metal ions in the glass composition of the glass strands of the present embodiment is preferably less than 0.90 parts by mass relative to 100 parts by mass of the total glass composition, and more It is preferably more than 0 part by mass and less than 0.90 part by mass.

＜Surface treatment＞ The surface of the glass cloth can be treated with a surface treatment agent. The surface treatment agent is not particularly limited, and for example, a silane coupling agent may be mentioned, and if necessary, water, an organic solvent, an acid, a dye, a pigment, a surfactant, etc. may be used in combination.

The silane coupling agent is not particularly limited. For example, the following formula (1) may be mentioned: X(R) _3-n SiY _n・・・(1) {wherein, X is an amine group and an unsaturated double bond At least one or more organic functional groups in the group, Y is each independently an alkoxy group, n is an integer of 1 or more and 3 or less, and R is each independently selected from the group consisting of methyl, ethyl and phenyl The compound shown in the base}.

In formula (1), X is preferably an organic functional group having at least 3 or more of amine groups and unsaturated double bond groups, and X is more preferably at least 4 or more of amine groups and unsaturated double bond groups. organofunctional group.

As the alkoxy group in the formula (1), from the viewpoint of stabilizing the glass cloth, an alkoxy group having 5 or less carbon atoms is preferable.

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-bis(vinylbenzyl)aminoethyl )-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-bis(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-aminopropyltriethoxysilane and its hydrochloride, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ- -(2-Aminoethyl)aminopropyltriethoxysilane, aminopropyltrimethoxysilane, vinyltrimethoxysilane, methacryloyloxypropyltrimethoxysilane, acrylonitrile Oxypropyltrimethoxysilane, etc. A single component of these, or a mixture of these can be used.

The molecular weight of the silane coupling agent is preferably 100-600, more preferably 150-500. It is also preferable to use two or more silane coupling agents having different molecular weights. By treating the surface of the glass yarn with two or more silane coupling agents having different molecular weights, the density of the surface treatment agent on the surface of the glass cloth tends to increase, and the reactivity with the matrix resin tends to be further improved.

<Glass yarn> The glass yarn described above which can adjust the chromaticity coordinate b ^* in the CIE L ^* a ^* b ^* colorimetric system of glass cloth to less than 3.9 is also an aspect of the present invention. That is, the glass yarn of this embodiment can have the same properties (except for the chromaticity coordinate b ^* ) and structure as the glass cloth described above.

More specifically, the glass yarn of the present embodiment is characterized in that it includes a plurality of glass filaments, and the glass filaments include one or more selected from the group consisting of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition. relative to 100 parts by mass of the total glass composition, the total of these components is 71 parts by mass to 100 parts by mass, and relative to 100 parts by mass of the total glass composition, the content of alkali metal ions in the glass composition of the glass strands Less than 0.90 parts by mass, alkali metals or alkaline earth metals adhered to the surface of the glass yarn, extracted with pure water and obtained by an ion chromatograph, the total adhesion amount of alkali metals and alkaline earth metals per unit surface area X (mg/m ² ) The total mass ratio k of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition satisfies the following formula: X[mg/m ² ]>(1.5[mg/m ² ])×k.

For glass yarn, the total amount of one or more components in the group consisting of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ , the alkali metal ion content, the total adhesion amount X (mg/m ² ), and the total mass The preferable range of the relationship of the ratio k may be the same as the range described with respect to the above-mentioned glass cloth. Among them, it is preferable to extract the surface of the glass yarn with pure water and obtain it by an ion chromatograph, the total adhesion amount X (mg/m ² ) of alkali metals and alkaline earth metals per unit surface area of the glass yarn and the glass composition. The total mass ratio k of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ further satisfies the following formula: X[mg/m ² ]<(15.0[mg/m ² ])×k.

＜Properties＞ From the viewpoint of large-capacity and high-speed data communication and signal processing, at a frequency of 10 GHz, the dielectric constant of the glass cloth of this embodiment is preferably less than 5.0, more preferably 4.9 or less or 4.8 or less, and further Preferably it is 4.7 or less, 4.5 or less, 4.4 or less, 4.0 or less, or 3.7 or less.

From the viewpoint of suppressing the fluff of the glass cloth, the breaking strength of the glass cloth of the present embodiment is preferably 180 N/mm ² or more, more preferably 200 N/mm ² or more, and still more preferably 220 N/mm ² or more. .

<Manufacturing method of glass cloth> The manufacturing method of the glass cloth of this embodiment is not particularly limited. For example, a method having the following steps can be exemplified: a weaving step, which involves weaving glass yarns to obtain glass cloth; a fiber opening step, which involves applying the glass yarns of the glass cloth Conduct fiber opening; and a desizing step, which is to remove the sizing agent (alias: paste) attached to the glass yarn of the glass cloth. Moreover, you may have the surface treatment process by surface treatment agents, such as a silane coupling agent, as needed.

The weaving method is not particularly limited as long as the weft yarns and the longitudinal yarns are folded so as to form a specific weaving structure. In addition, the fiber opening method is not particularly limited, and for example, a method of performing fiber opening processing by a water jet (high-pressure water opening), a vibration washer, ultrasonic water, a rolling machine, or the like can be exemplified.

Furthermore, the desizing method is not particularly limited, and for example, a method of removing the sizing agent by heating can be mentioned. In addition, the sizing agent is used to protect the glass yarn from breakage or the like in the weaving step or the like. Although it does not specifically limit about such a sizing agent, For example, a starch-type adhesive agent and a polyvinyl alcohol-type adhesive agent are mentioned. Furthermore, the temperature for removing the sizing agent by heating is preferably 300°C to 500°C, more preferably 330°C to 450°C, from the viewpoint of sufficiently removing the sizing agent while maintaining the breaking strength. Preferably it is 350 degreeC - 430 degreeC.

In addition, regarding the conditions for heat removal, for the purpose of adjusting the chromaticity coordinates b ^* of the above-mentioned CIE L ^* a ^* b ^* colorimetric system, a temperature higher than the above-mentioned temperature range can also be used, and the temperature is preferably 500℃～ 800°C, more preferably 550°C to 750°C, still more preferably 600°C to 700°C.

In the case of heat removal by a batch-type thermal cleaning method, the heating time is preferably 6 to 66 hours, more preferably 10 to 50 hours, and further preferably 15 to 45 hours. If the heating time is too short, the b ^* value will be larger than the target range, and if the heating time is too long, the b ^* value will be smaller than the target range.

Furthermore, from the viewpoint of more suitable control of the b ^* value, compared with the continuous thermal cleaning method in which the wound body of the glass fiber fabric is continuously passed through a heating furnace and treated in a short time while being rolled out. , batch-type thermal cleaning method for long-term processing is preferred.

Moreover, as a surface-treating method, the method of making the surface-treating agent containing a surface-treating agent (for example, a silane coupling agent) contact a glass cloth, and drying, etc. are mentioned. Furthermore, regarding the contact between the surface treatment agent and the glass cloth, there may be mentioned: the method of dipping the glass cloth in the surface treatment agent; or the method of using a roll coater, die coater, or gravure coater Method of coating surface treatment agent on cloth, etc. It does not specifically limit about the drying method of a surface treatment agent, For example, the drying method using hot air drying or an electromagnetic wave is mentioned.

＜Prepreg＞ The prepreg of this embodiment has the glass cloth demonstrated above, and the matrix resin composition impregnated in this glass cloth. The insulation reliability of the prepreg containing glass cloth will be further improved, and the yield of the final product will be higher. In addition, due to its excellent dielectric properties and excellent moisture absorption resistance, it can also exert the effect of providing a printed circuit board that is less affected by the use environment, especially in a high humidity environment. Small.

The prepreg of this embodiment can be conventionally manufactured. For example, it can be produced by impregnating the glass cloth of the present embodiment with a varnish obtained by diluting a matrix resin such as an epoxy resin with an organic solvent, and then volatilizing the organic solvent in a drying oven to make the thermosetting resin Hardened to the B-stage state (semi-hardened state).

As the matrix resin composition, in addition to the above-mentioned epoxy resins, bismaleimide resins, cyanate ester resins, unsaturated polyester resins, polyimide resins, BT (Bismaleimide Triazine, bismaleimide resins, etc.) Thermosetting resins such as lyimide triazine) resin and functionalized polyphenylene ether resin; polyphenylene ether resin, polyether imide resin, liquid crystal polymer (LCP) of wholly aromatic polyester, polybutylene Thermoplastic resins such as olefins, fluororesins, etc.; mixed resins thereof, etc. From the viewpoint of improving dielectric properties, reliability, solvent resistance, and press moldability, resins obtained by modifying thermoplastic resins with thermosetting resins can also be used as the matrix resin composition.

In addition, the matrix resin composition may also include in the resin: inorganic fillers such as silicon dioxide and aluminum hydroxide; flame retardants such as bromine-based, phosphorus-based, metal hydroxides; other silane coupling agents; thermal stabilizers; Static agents; UV absorbers; pigments; colorants; lubricants, etc.

＜Printed circuit board＞ The printed circuit board of this embodiment includes the glass cloth described above, and a cured product of the matrix resin impregnated in the glass cloth. The printed circuit board of this embodiment not only improves the reliability, but also improves the yield rate of the final product, and also has excellent dielectric properties, which can be adapted to the use environment. [Example]

Hereinafter, the present invention will be described in more detail using Examples and Comparative Examples, but the present invention is not limited by the following Examples at all.

<Example 1> Glass yarns (average diameter of filaments: 7.0 μm, wire count: 200 pieces) having the composition shown in Glass Type A in Table 2 were woven by an air-jet loom, and the weaving densities of warp and weft yarns were respectively 60 pieces/ inch and 58/inch glass cloth with a thickness of 91 μm. Next, a thermal cleaning process was performed at 530° C. for 12 hours by heating, and a fiber opening step was performed by high-pressure water spray to obtain an intermediate of glass cloth with a width of 1285 mm and a length of 2000 m. Next, the intermediate body was surface-treated using a silane coupling agent to prepare a glass cloth.

<Example 2> A glass cloth was obtained in the same manner as in Example 1, except that the thermal cleaning treatment conditions were changed to 630° C. and 24 hours.

<Examples 3 to 5> Glass yarns (average diameter of filaments: 7.0 μm, yarn count: 200) having the composition shown in Glass Type A in Table 2 were woven by an air-jet loom to obtain weave of warp and weft yarns. Glass cloth with a density of 60 pieces/inch and 58 pieces/inch, and a thickness of 91 μm, respectively. Next, an aqueous solution obtained by dissolving sodium bicarbonate (NaHCO ₃ ) in water was applied on a glass cloth using a two-fluid nozzle. The amount of the compound shown in Table 1 was extracted from the glass cloth after hot air drying. Next, a 24-hour thermal cleaning process was performed at 400° C. by heating, and a fiber opening step was performed by high-pressure water spray to obtain an intermediate of glass cloth with a width of 1285 mm and a length of 2000 m. Finally, glass cloth is produced by surface-treating the intermediate body with a silane coupling agent.

<Example 6> A glass cloth was produced in the same manner as in Example 1, except that the glass species B in Table 2 was used and the thermal cleaning time was set to 24 hours.

<Example 7> A glass cloth was produced in the same manner as in Example 2 except that the glass species B in Table 2 was used.

<Examples 8 to 10> A glass cloth was produced in the same manner as in Examples 3 to 5 except that the glass species B in Table 2 was used.

<Comparative Example 1> A glass cloth was obtained in the same manner as in Example 1, except that the temperature condition of the thermal cleaning treatment was changed to 400° C. and the time condition was changed to 24 hours.

<Comparative Example 2> A glass cloth was obtained in the same manner as in Example 6, except that the temperature condition of the thermal cleaning treatment was changed to 400°C.

<Comparative Example 3> A glass cloth was obtained in the same manner as in Example 1, except that the thermal cleaning treatment was carried out at 540° C. for 90 seconds and then at 650° C. for 80 seconds using a continuous thermal cleaning method.

<Comparative Example 4> A glass cloth was obtained in the same manner as in Example 6, except that the thermal cleaning treatment was carried out at 540° C. for 90 seconds and then at 650° C. for 80 seconds using a continuous thermal cleaning method.

＜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 the weft, the thread count, and the weaving density of the warp and weft (weaving density) were measured in accordance with JIS R3420.

<The composition of glass yarn> The composition constituting the glass yarn was measured by ICP emission spectrometry. Specifically, the Si content and the B content can be obtained by: dissolving the weighed glass cloth sample with sodium carbonate, dissolving it with dilute nitric acid and diluting to volume, and measuring the obtained sample by ICP emission spectrometry. In addition, the Al content, Ca content, P content, Ti content and Mg content can be obtained by the following method: after heating and decomposing the weighed glass cloth sample with sulfuric acid, nitric acid and hydrogen fluoride, dissolving and constant volume with dilute nitric acid, using The resulting samples were measured by ICP emission spectrometry. Furthermore, as an ICP emission spectrometer, PS3520VDD II manufactured by Hitachi High-Tech Science was used.

<CIE L ^* a ^* b ^* Colorimetric System> Using a spectrophotometer (CM-2600d, manufactured by Konica Minolta), the L ^* a ^* b ^* colorimetric of glass cloth was measured according to JIS Z8781 (2005). system. In addition, regarding the measurement of the b ^* value, the glass cloth was superimposed on the white plate as a reference (control) so that the thickness may be 2.0 mm or more, and the measurement was performed in this state, and the average value of the 5 measured values was taken.

<Dielectric constant> As described below, a substrate was prepared so that the resin content per 100 mass % of the prepreg was 60 mass %, and the copper foil was removed to obtain a sample for dielectric constant evaluation. The dielectric constant of the obtained sample at a frequency of 1 GHz was measured using an impedance analyzer (manufactured by Agilent Technologies). Based on the volume fraction of the glass cloth and the resin dielectric constant of 2.5, the dielectric constant of the glass cloth was calculated from the obtained substrate dielectric constant.

<Dissolution amount of alkali metals and alkaline earth metals> 1.42 parts by mass of glass cloth was completely immersed (full immersion) in 100 parts by mass of distilled water at normal temperature (25° C.), and left for 5 hours. The solution after the dissolution of the substance) was used to obtain the dissolution amount of alkali metal ions and alkaline earth metal ions from the glass cloth. Blank samples were measured using distilled water only. Based on the average diameter of the filaments and the number of filaments, the amount of adhesion per unit surface area of the glass cloth was calculated from the obtained measured values.

<The production method of the laminated board> The epoxy resin varnish (40 mass parts of low-brominated bisphenol A type epoxy resin, 10 mass parts of o-cresol type novolac epoxy resin, 50 mass parts of dimethylformamide, bisphenol A A mixture of 1 part by mass of cyanamide and 0.1 part by mass of 2-ethyl-4-methylimidazole) was impregnated into the glass cloth obtained in the above Examples and Comparative Examples, and dried at 160° C. for 2 minutes to obtain a prepreg . The prepreg was stacked, and copper foils with a thickness of 12 μm were stacked on top and bottom of the prepreg, and the laminate was obtained by heating and pressing under the conditions of 180° C. and 40 kg/cm ² for 60 minutes.

<Method for evaluating insulation reliability of laminates> As described above, a laminate was fabricated so that the thickness was 1.0 mm, and wiring patterns in which through-holes were arranged at intervals of 0.30 mm were formed on the copper foils on both sides of the laminate to obtain samples for insulation reliability evaluation. A voltage of 50 V was applied to the obtained sample in an atmosphere with a temperature of 85° C. and a humidity of 85% RH, and the change in the resistance value was measured. At this time, the case where the resistance did not reach 1 MΩ within 500 hours after the start of the test was counted as insulation failure. The same measurement was performed on 10 samples, and the ratio of the samples that did not become poor insulation among the 10 samples was calculated.

<Break strength measurement> The elongation when tension is applied to the glass cloth in the warp direction or the weft direction is measured by the treatment method according to the general test method for glass testing of JIS R3420, and the method described in Item 7.4.2 (Crossover).

As can be seen from the results in Table 3, the laminates made of the low-dielectric glass cloth having adjusted chromaticity coordinates b ^* of the present invention have higher reliability than those of the comparative examples. In particular, the low dielectric glass cloths coated with alkali metals or alkaline earth metals of Examples 3 to 5 and 8 to 10 showed the best reliability.

[Table 1] Glass type: A ⁽ⁱ⁾ Na ⁺ K ⁺ Mg ²⁺ total 1.5×k k: 0.725 mg/m ² mg/m ² mg/m ² mg/m ² mg/m ² water for extraction 0.01 0.00 0.02 0.03 1.09 Comparative Example 1 0.31 0.12 0.04 0.47 Comparative Example 3 0.31 0.12 0.04 0.47 Example 1 0.30 0.14 0.04 0.48 Example 2 0.31 0.12 0.04 0.47 Example 3 3.21 0.01 0.02 3.24 Example 4 0.30 5.44 0.02 5.76 Example 5 11.3 0.12 0.02 11.4 Glass type: B ⁽ⁱ⁾ Na ⁺ K ⁺ Mg ²⁺ total 1.5×k k: 0.790 mg/m ² mg/m ² mg/m ² mg/m ² mg/m ² water for extraction 0.01 0.00 0.02 0.03 1.19 Comparative Example 2 0.26 0.11 0.02 0.38 Comparative Example 4 0.26 0.11 0.02 0.38 Example 6 0.27 0.11 0.02 0.39 Example 7 0.28 0.12 0.02 0.41 Example 8 5.30 0.11 0.02 5.42 Example 9 0.27 9.60 0.02 9.88 Example 10 0.26 0.10 5.60 5.96 ⁽ⁱ⁾ The composition of the glass species in Table 1 is shown in Table 2.

[Table 2] parts by mass Glass type: A Glass type: B _SiO2 55 50 B ₂ O ₃ 17.5 25 P ₂ O ₅ 0 4 R ₂ O (alkali metal) <0.9 <0.9 RO (Alkaline Earth Metal) <9.9 <9.9 k (content ratio of SiO ₂ +B ₂ O ₃ +P ₂ O ₅ ) 0.725 0.79 Dielectric constant@10 GHz 4.70 4.46

[table 3] Glass type: A L ^* a ^* b ^* Color System SCE Extraction amount reliability evaluation Breaking strength k: 0.725 a ^* b ^* mg/m ² - N/mm ² Comparative Example 1 0.85 4.20 0.47 1 262.0 Comparative Example 3 1.23 4.15 0.47 1 262.5 Example 1 0.46 3.87 0.48 3 246.1 Example 2 0.13 1.68 0.47 3 191.6 Example 3 0.31 3.06 3.24 10 236.9 Example 4 0.41 3.82 5.76 4 246.1 Example 5 0.15 1.82 11.4 4 222.3 Glass type: B L ^* a ^* b ^* Color System SCE Extraction amount reliability evaluation Breaking strength k: 0.790 a ^* b ^* mg/m ² - N/mm ² Comparative Example 2 1.83 4.92 0.38 1 238.7 Comparative Example 4 1.42 4.24 0.38 1 237.5 Example 6 0.73 3.89 0.39 3 226.1 Example 7 0.34 1.97 0.41 3 182.3 Example 8 0.51 3.75 5.42 5 224.4 Example 9 0.56 3.82 9.88 4 225.5 Example 10 0.38 3.45 5.96 7 221.4

Claims (11)

A glass cloth, which is composed of glass yarns including a plurality of glass filaments as warps and wefts, wherein the glass filaments in the glass composition include selected from the group consisting of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ . One or more components, the total of these components is 71 parts by mass to 100 parts by mass relative to 100 parts by mass of the total glass composition, and the glass cloth is in the CIE L ^* a ^* b ^* colorimetric system, and the chromaticity is Coordinate b ^* does not reach 3.9. The glass cloth of claim 1, wherein the chromaticity coordinate b ^* is b ^* <3.6. The glass cloth of claim 1, wherein the chromaticity coordinate b ^* is b ^* <3.3. The glass cloth according to any one of claims 1 to 3, wherein the chromaticity coordinate b ^* is greater than 2.0. The glass cloth according to any one of claims 1 to 3, wherein an alkali metal or an alkaline earth metal is attached to the surface of the glass cloth, the alkali metal and the alkaline earth metal are extracted with pure water, and the unit is determined by an ion chromatograph The total adhesion amount X (mg/m ² ) of alkali metals and alkaline earth metals on the surface area, the total adhesion amount X (mg/m ² ) and the total of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition The mass ratio k satisfies the following formula: X[mg/m ² ]>(1.5[mg/m ² ])×k. The glass cloth according to claim 5, wherein the total adhesion amount X (mg/m ² ) and the total mass ratio k satisfy the following formula: X[mg/m ² ]<(15.0[mg/m ² ])×k . The glass cloth according to any one of claims 1 to 3, wherein the content of alkali metal ions in the glass composition of the glass filaments is less than 0.90 parts by mass relative to 100 parts by mass of the total glass composition. A prepreg comprising: If the glass cloth of any one of Claims 1 to 7, and The matrix resin impregnated in the glass cloth. A printed circuit board comprising: If the glass cloth of any one of Claims 1 to 7, and The hardened product of the matrix resin impregnated in the glass cloth. A glass yarn comprising a plurality of glass filaments, wherein the glass filaments contain one or more components selected from the group consisting of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the glass composition, relative to the total glass 100 parts by mass of components, the total of these components is not less than 71 parts by mass and not more than 100 parts by mass, and the content of alkali metal ions in the glass composition of the glass filaments is less than 0.90 parts by mass relative to 100 parts by mass of the total glass composition, Alkali metal or alkaline earth metal adhered to the surface of the above-mentioned glass yarn, extracted with pure water and obtained by ion chromatograph, the total adhesion amount of alkali metal and alkaline earth metal per unit surface area X (mg/m ² ) and glass The total mass ratio k of SiO ₂ , B ₂ O ₃ , and P ₂ O ₅ in the composition satisfies the following formula: X[mg/m ² ]>(1.5[mg/m ² ])×k. The glass yarn according to claim 10, wherein the total adhesion amount X (mg/m ² ) and the total mass ratio k satisfy the following formula: X[mg/m ² ]<(15.0[mg/m ² ])×k .