Low dielectric glass cloth, prepreg, and printed wiring board

Abstract

An object of the present invention is to provide a glass cloth and a glass yarn excellent in insulation reliability, and a prepreg and a printed wiring board including the same.SOLUTION: Provided is a glass cloth including glass yarns composed of a plurality of glass filaments as warp yarns and weft yarns, wherein the glass filaments contain one or more components selected from the group consisting of SiO2, B2O3, and P2O5 in a glass composition, a total amount of the components is 71 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of all glass composition components, and a chrominance coordinate b * in a CIEL * a * b * color system is less than 3.9.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a low dielectric glass cloth, a prepreg, a printed wiring board, and the like. [Background technology]

[0002] With the recent development of the information and communications society, data communication and / or signal processing have become large-volume and high-speed, and the dielectric constant of printed wiring boards used in electronic devices has been significantly reduced. For this reason, many low-dielectric glass cloths have been proposed as glass cloths for use in printed wiring boards.

[0003] For example, the low dielectric glass cloth disclosed in Patent Document 1 contains a larger amount of B2O3 in the glass composition than the E-glass cloth that has been commonly used in the past, and at the same time, the amounts of other components such as SiO2 are also adjusted. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-262632 Summary of the Invention [Problem to be solved by the invention]

[0005] If the B2O3 content in the glass yarn is increased to reduce the dielectric constant of the glass cloth, the elastic modulus of the glass yarn decreases, making the glass yarn more susceptible to breakage during the manufacturing process. Therefore, as described in Patent Document 1, glass fiber bundles are coated with a sizing agent (also known as a glue agent) during spinning or warping, and after weaving, a process called heat cleaning is carried out to remove the sizing agent, which is an organic substance adhering to the glass fiber bundles.

[0006] As described in Patent Document 1, heat cleaning methods that have been commonly used include, for example, a batch-type heat cleaning method at 350 to 500° C. or a heat cleaning method in which a glass fabric is continuously passed through a heating furnace at a high temperature of 550 to 700° C. However, it has been found that when such heat cleaning methods are applied to low dielectric glass cloth, prepregs obtained from the heat-cleaned glass cloth contain prepregs with poor insulation reliability due to combustion residues and the like.

[0007] In view of the above problems, an object of the present invention is to provide a glass cloth and glass yarn having excellent insulating reliability, as well as a prepreg and a printed wiring board containing the same. [Means for solving the problem]

[0008] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by adjusting the hue of a glass cloth having a predetermined glass composition, and have thus completed the present invention.

[0009] That is, the present invention is as follows. [1] A glass cloth constructed by using glass yarns consisting of a plurality of glass filaments as warp and weft yarns, wherein the glass filaments contain one or more components selected from the group consisting of SiO2, B2O3, and P2O5 in their glass composition, and the total amount of these components is 71 parts by mass or more and 100 parts by mass or less per 100 parts by mass of all glass composition components, and the glass cloth is made of a material selected from the group consisting of glass yarns consisting of a plurality of glass filaments as warp and weft yarns ... * a * b * In the color system, the chrominance coordinate b * However, the glass cloth has a viscosity of less than 3.9. [2] The chrominance coordinate b * But, b * <3.6. [3] The chrominance coordinate b * But, b *<3.3. [4] The chrominance coordinate b * The glass cloth according to any one of items [1] to [3], wherein the value of the tensile strength is greater than 2.0. [5] An alkali metal or alkaline earth metal is attached to the surface of the glass cloth, and the alkali metal and the alkaline earth metal are extracted with pure water and measured by ion chromatography to obtain a total attached amount X (mg / m) of the alkali metal and the alkaline earth metal per surface area. 2 ) and the total mass ratio k of SiO2, B2O3, and P2O5 in the glass composition are expressed by the following formula: X [mg / m 2 ] > (1.5[mg / m 2 ])×k The glass cloth according to any one of items [1] to [4], which satisfies the above. [6] The total adhesion amount X (mg / m 2 ) and the total mass ratio k are expressed by the following formula: X [mg / m 2 ] < (15.0[mg / m 2 ])×k The glass cloth according to item [5], which satisfies the above. [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 per 100 parts by mass of all glass composition components. [8] The glass cloth according to any one of items [1] to [7], a matrix resin impregnated in the glass cloth; A prepreg comprising: [9] The glass cloth according to any one of items [1] to [7], a cured product of the matrix resin impregnated into the glass cloth; A printed wiring board comprising:

[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 SiO2, B2O3, and P2O5 in their glass composition, the total of these components being 71 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of all glass composition components, 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 all glass composition components, alkali metals or alkaline earth metals are attached to the surfaces of the glass yarns, and the total amount of alkali metal and alkaline earth metal attachment per surface area, X (mg / m), is determined by ion chromatography after extraction with pure water. 2 ) and the total mass ratio k of SiO2, B2O3, and P2O5 in the glass composition are expressed by the following formula: X [mg / m 2 ] > (1.5[mg / m 2 ])×k Meet the glass thread.

[11] The total adhesion amount X (mg / m 2 ) and the total mass ratio k are expressed by the following formula: X [mg / m 2 ] < (15.0[mg / m 2 ])×k The glass fiber according to item

[10] , which satisfies the above. [Effects of the Invention]

[0010] According to the present invention, a glass cloth and glass yarn having excellent insulating reliability can be provided, and the insulating reliability of a prepreg or printed wiring board containing them is also excellent. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an 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 can be made without departing from the spirit of the present invention. In this specification, the dielectric constant refers to the value at a frequency of 10 GHz unless otherwise specified.

[0012] <Glass cloth> The glass cloth according to the present embodiment is configured by using glass yarns consisting of a plurality of glass filaments as warp and weft yarns, and the glass filaments contain one or more components selected from the group consisting of SiO2, B2O3, and P2O5 in their glass composition, and the total amount of these components is 71 parts by mass or more and 100 parts by mass or less per 100 parts by mass of all glass composition components, and is CIE L * a * b * In the color system, the chrominance coordinate b * The value is smaller than 3.9. Also, the above chrominance coordinate b * The value is preferably greater than 2.0. Furthermore, the total content of one or more components selected from the group consisting of SiO2, B2O3, and P2O5 in the glass composition of the glass filaments is preferably 72 parts by mass or more and 90 parts by mass or less, more preferably 72.5 parts by mass or more and 85 parts by mass or less, per 100 parts by mass of all glass composition components.

[0013] <Hue> CIE L of the glass cloth according to this embodiment * a * b * In the color system, chrominance coordinate b * is a value smaller than 3.9, and preferably a value greater than 2.0. * a * b * The color system was standardized by the International Commission on Illumination (CIE) in 1976 and is measured according to JIS Z8781 (2016). * a * b * In the color system, chrominance coordinate b * represents a hue ranging from blue (minimum value: -60) to yellow (maximum value: +60).

[0014] According to the present invention, at least a part of the highly reliable glass cloth structure is L * a * b * Color Space 2.0 * ​It was found that the value was <3.9. Although not wishing to be bound by theory, it is possible that the yellowing components in the conventional low dielectric glass cloth may inhibit the surface treatment of the glass cloth with a silane coupling agent in the subsequent process. However, L * a * b * Color system: 2.0 * It is thought that glass cloth with a viscosity of <3.9 tends to have less yellowing or has been surface-treated more efficiently.

[0015] Glass cloth L * a * b * Color space b * From the viewpoint of further improving reliability, the value should be 3.6 or less, or less than 3.6 (b * <3.6), 3.3 or less, less than 3.3 (b * <3.3), or 3.0 or less. * The lower limit of the value is preferably a value exceeding 2.0 from the viewpoint of suppressing fluffing of the glass cloth.

[0016] Glass cloth CIE L * a * b * In the color system, chrominance coordinate b * can be adjusted to a value less than 3.9, for example, by suppressing yellowing by increasing the temperature or time conditions of the heat cleaning treatment described below, and / or by performing the glass cloth attachment treatment described below.

[0017] <Glass composition> ​The glass composition according to this embodiment will be described below. In the composition of the glass fiber according to this embodiment, the total mass of silicon (Si) and boron (B) converted into SiO2 and B2O3, respectively, is 70 mass% or more, based on the mass of the glass fiber. When the total content of Si and B converted into SiO2 and B2O3 is 70 mass% or more, the dielectric constant tends to decrease. From this perspective, in the composition of the glass fiber, the total content of Si and B converted into SiO2 and B2O3 is preferably 72.5 mass% or more, or 75 mass% or more. The upper limit of the total content of Si and B converted into SiO2 and B2O3 can be less than 100 mass%, and / or the Si content can be less than 100 mass% converted into SiO2.

[0018] The Si content of the glass yarn is preferably 40% by mass or more in terms of SiO2, as long as the total content of Si and B in terms of SiO2 and B2O3 is 70% by mass or more, and more preferably 45% by mass or more, 47% by mass or more, or 48% by mass or more, and the upper limit can be less than 100% by mass or 99.9% by mass or less.

[0019] Silicon (Si) is a component that forms the skeletal structure of the glass yarn, and when the Si content is 40% by mass or more in terms of SiO2, the strength of the glass yarn is further improved, and breakage of the glass cloth tends to be further suppressed in the glass cloth manufacturing process and in post-processes such as the manufacture of prepregs using the glass cloth. Furthermore, when the Si content is 40% by mass or more in terms of SiO2, the dielectric constant of the glass cloth tends to be further reduced.

[0020] The B content of the glass yarn is preferably 15% to 30% by mass, more preferably 17% to 28% by mass, and even more preferably 17.5% to 25% by mass, calculated as B2O3, as long as the total content of Si and B calculated as SiO2 and B2O3 is 70% by mass or more. A B content of 15% by mass or more tends to further reduce the dielectric constant. Furthermore, a B content of 30% by mass or less tends to improve moisture absorption resistance and further improve insulation reliability.

[0021] Furthermore, the glass filaments according to this embodiment may contain Fe, F, Al, Ca, Mg, P, Na, K, Ni, Ti, Zn, or a combination thereof, as long as the total content of Si and B in the glass composition is 70 mass% or more in terms of SiO2 and B2O3.

[0022] The Al content of the glass yarn is preferably 12 to 16 mass % in terms of Al2O3 from the viewpoint of electrical properties or strength.

[0023] The P content of the glass yarn, calculated as P2O5, is preferably 0.1% by mass to 6% by mass, more preferably 2.0% by mass to 5.5% by mass. A P content of 0.1% by mass or more calculated as P2O5 tends to further reduce the dielectric constant. Furthermore, a P content of 6% by mass or less calculated as P2O5 tends to reduce the likelihood of breakage when the glass cloth passes through a squeeze roll or nip roll in a wet state during the opening step or surface treatment step in glass cloth production. Furthermore, phase separation during glass filament production is suppressed, further improving the moisture absorption resistance of the resulting glass filaments. This makes the resulting printed wiring board less susceptible to the effects of high-humidity usage environments, reducing the environmental dependency of the dielectric constant.

[0024] The Ca content of the glass yarn is preferably 1% by mass to 5% by mass, and more preferably 2% by mass to 4% by mass, calculated as CaO. When the Ca content is 1% by mass or more, calculated as CaO, the viscosity at the time of melting tends to be lowered in the manufacturing process of the glass filament, and glass fibers with a more homogeneous glass composition tend to be obtained. Furthermore, when the Ca content is 5% by mass or less, calculated as CaO, the dielectric constant tends to be improved.

[0025] The Mg content of the glass yarn is preferably 0.01% by mass to 5% by mass, calculated as MgO. When the Mg content is 5% by mass or less, calculated as MgO, the glass cloth tends to be less likely to break when passing through squeeze rolls, nip rolls, or the like in a wet state during the opening step or surface treatment step in the manufacture of the glass cloth. Furthermore, phase separation during the manufacture of the glass filaments is suppressed, further improving the moisture absorption resistance of the resulting glass filaments. This makes the resulting printed wiring board less susceptible to the effects of high-humidity environments in which it is used, reducing the environmental dependency of the dielectric constant.

[0026] The contents of Si, B, Al, P, Ca, and Mg can be adjusted depending on the amounts of raw materials used in producing the glass filaments. The contents of each element described above can be measured by extracting glass yarns from the glass cloth and subjecting them to inductively coupled plasma (ICP) atomic emission spectroscopy. For example, a PS3520VDD II manufactured by Hitachi High-Tech Science Corporation can be used as the ICP atomic emission spectroscopy analyzer.

[0027] Specifically, the Si content, the B content, and the total content of Si and B can be obtained by fusing a weighed glass cloth sample with sodium carbonate, dissolving it in dilute nitric acid to a constant volume, and measuring the obtained sample by ICP atomic emission spectroscopy.

[0028] Furthermore, the Al content, Ca content, and Mg content can be obtained by subjecting a weighed glass cloth sample to thermal decomposition with sulfuric acid, nitric acid, and hydrogen fluoride, dissolving the sample in dilute nitric acid, adjusting the volume, and measuring the resulting sample by ICP atomic emission spectroscopy.

[0029] <Configuration> Glass yarn is obtained by bundling a plurality of glass filaments and twisting them as necessary, and glass cloth is obtained by weaving the above glass yarns as warp and weft. Glass yarns are classified into multifilaments, and glass filaments are classified into monofilaments.

[0030] The average radius of the glass filaments constituting the warp and weft yarns is preferably 2.5 μm to 9 μm, more preferably 3.0 μm to 7.5 μm, and even more preferably 3.5 μm to 5.4 μm. When the average diameter of the glass filaments is within the above range, the processability of the resulting substrate tends to be improved when processed using a mechanical drill, a carbon dioxide laser, or a UV-YAG laser. This makes it possible to realize a thin, high-density printed wiring board. In particular, when the average radius is 5.4 μm or less, the surface area per unit volume increases, making it easier for hygroscopic viscous substances derived from the sizing agent to adhere, making the effect of improving insulation reliability of this embodiment even more important. Furthermore, when the average radius is 2.5 μm or more, the glass cloth tends to be less likely to break when passing through squeeze rolls or nip rolls in a wet state during the glass cloth manufacturing process, including the fiber-opening step or surface treatment step. Furthermore, in post-processes such as the production of prepregs, when the glass cloth is passed through a slit for the purpose of controlling the amount of resin impregnated into the glass cloth, breakage tends to be less likely to occur.

[0031] The density of the warp and weft yarns constituting the glass cloth is preferably 30 to 120 yarns / inch, more preferably 40 to 110 yarns / inch, and even more preferably 50 to 100 yarns / inch.

[0032] The thickness of the glass cloth is preferably 8 μm to 100 μm, more preferably 10 μm to 70 μm, and even more preferably 12 μm to 50 μm. When the thickness of the glass cloth is within the above range, a thin glass cloth with relatively high strength tends to be obtained.

[0033] The fabric weight (basis weight) of the glass cloth is preferably 8 g / m 2 ~250g / m 2 and more preferably 8 g / m 2 ~100g / m 2 and more preferably 8 g / m 2 ~50g / m 2and particularly preferably 8 g / m 2 ~35g / m 2 is.

[0034] The weave structure of the glass cloth is not particularly limited, but examples thereof include plain weave, sash weave, satin weave, twill weave, etc. Among these, the plain weave structure is more preferred.

[0035] <Adhesion treatment> The glass cloth according to this embodiment is preferably coated with an alkali metal or alkaline earth metal-containing compound, and more preferably coated with an alkali metal or alkaline earth metal-containing compound on its surface. * a * b * In the color system, the chrominance coordinate b * This makes it easier to adjust the value to less than 3.9. Furthermore, if a treatment for attaching an alkali metal or alkaline earth metal-containing compound is carried out before the desizing (heat cleaning) step for removing the sizing agent by heating in the glass cloth manufacturing process, yellowing after heat cleaning can be reduced.

[0036] The alkali metal or alkaline earth metal-containing compound attached to the glass yarn and the glass cloth preferably contains an alkali metal from the viewpoint of improving the reliability of the glass cloth, and more preferably contains sodium (Na) from the viewpoint of further improving the reliability of the glass cloth.

[0037] The Na-containing compound attached to the glass cloth is not limited, but examples thereof include sodium chloride (NaCl) and sodium carbonate (Na2CO3).

[0038] The alkaline earth metal-containing compound attached to the glass cloth preferably contains Mg, and examples thereof include, but are not limited to, MgCl2.

[0039] The total amount of alkali metal and alkaline earth metal attached to the glass cloth can be measured by extraction with pure water, for example, by measuring the amount eluted in distilled water. The amount eluted can be detected by ion chromatography.

[0040] From the measurements obtained by the above method, the amount of alkali metal and alkaline earth metal attached per surface area of ​​the glass cloth can be determined. The surface area of ​​the glass cloth is determined from the diameter of the fibers used and the number of fibers per glass thread. The determined value X is calculated by b * From the viewpoint of adjusting the value to an appropriate value, it is preferable to satisfy the following formula, which includes the combined mass ratio k of SiO2, B2O3, and P2O5 in the glass composition: X [mg / m 2 ] > (1.5[mg / m 2 ])×k This numerical value X is more preferably 2.0×k or more, and even more preferably 2.5×k or more.

[0041] In addition, in the above formula, the lower limit of the adhesion amount X is preferably less than 15.0×k from the viewpoint of maintaining the breaking strength.

[0042] The value of 1.5 × k corresponds to approximately 0.024 parts by mass of a glass cloth woven using glass type A (shown in Table 2 below) with 200 fibers at a warp density of 60 threads / inch and a weft density of 58 threads / inch.

[0043] The degree of yellowing varies depending on the ratio of SiO2, B2O3, and P2O5 in the glass composition, which in turn changes the required coating weight. Without wishing to be bound by theory, it is thought that when glass is made to have a low dielectric constant, the ratio of SiO2, B2O3, and P2O5 in the composition increases, which reduces the alkaline earth metal content.

[0044] The method of attachment is not particularly limited, but examples thereof include a method of attaching alkali metals and / or alkaline earth metals to glass yarns and then weaving a glass cloth, or a method of attaching alkali metals and / or alkaline earth metals to woven glass cloth. Examples of attachment methods include, but are not limited to, a method of applying an aqueous solution of alkali metal and / or alkaline earth metal compounds to glass cloth or glass yarns using a two-fluid nozzle, or a method of immersing glass cloth or glass yarns in the aqueous solution and drying it.

[0045] Another possible method is to add alkali metals and / or alkaline earth metals to the raw glass, but from the viewpoint of dielectric constant and breaking strength, it is more preferable that the added components are present only on the surface.Also, it is possible to add alkali metals and / or alkaline earth metals to a sizing agent and apply it to the glass yarn, but from the viewpoint of the effects of the present invention, it is more preferable that the added components are present on the surface of the glass cloth.

[0046] From the viewpoint of appropriately achieving the effects described above, the content of alkali metal ions in the glass composition of the glass filament according to this embodiment is preferably less than 0.90 parts by mass, and more preferably more than 0 parts by mass and less than 0.90 parts by mass, per 100 parts by mass of all glass composition components.

[0047] <Surface treatment> The surface of the glass cloth can be treated with a surface treatment agent. The surface treatment agent is not particularly limited, but examples thereof include a silane coupling agent, and water, an organic solvent, an acid, a dye, a pigment, a surfactant, etc. may be used in combination as needed.

[0048] The silane coupling agent is not particularly limited, but examples thereof include those represented by the following formula (1): X(R) 3-n SiY n ···(1) In the formula, X represents an organic functional group having at least one of an amino group and an unsaturated double bond group, each Y represents an alkoxy group, n represents an integer of 1 to 3, and each R represents a group independently selected from the group consisting of a methyl group, an ethyl group, and a phenyl group. Examples of compounds include those represented by the following formula:

[0049] In formula (1), X is preferably an organic functional group having at least three or more amino groups and unsaturated double bond groups, and more preferably an organic functional group having at least four or more amino groups and unsaturated double bond groups.

[0050] The alkoxy group in formula (1) is preferably an alkoxy group having 5 or less carbon atoms from the viewpoint of stabilizing the treatment of the glass cloth.

[0051] 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, and N-β-(N-di(vinylbenzyl)aminoethyl)-N-γ-(N-vinylbenzyl)-γ-aminopropyltrimethoxysilane and its hydrochloride. hydrochloride thereof, N-β-(N-benzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-benzylaminoethyl)-γ-aminopropyltriisoethoxysilane and its hydrochloride, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltriethoxysilane, aminopropyltrimethoxysilane, vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, etc. Any of these may be used alone or in combination.

[0052] The molecular weight of the silane coupling agent is preferably 100 to 600, more preferably 150 to 500. It is also preferable to use two or more silane coupling agents with different molecular weights. Treating the surface of the glass yarn with two or more silane coupling agents with different molecular weights increases the density of the surface treatment agent on the surface of the glass cloth, and tends to further improve the reactivity with the matrix resin.

[0053] <Glass thread> The CIE L of the glass cloth described above * a * b * Chrominance coordinate b in the color system * The glass yarn capable of adjusting the chrominance coordinate b to less than 3.9 is also one aspect of the present invention. That is, the glass yarn according to this embodiment has the same properties as the glass cloth described above (except for the chrominance coordinate b * (excluding) and configuration.

[0054] More specifically, the glass yarn according to this embodiment is composed of a plurality of glass filaments, the glass filaments contain one or more components selected from the group consisting of SiO2, B2O3, and P2O5 in their glass composition, the total of these components is 71 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of all the glass composition components, 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 all the glass composition components, alkali metals or alkaline earth metals are attached to the surfaces of the glass yarns, and the total amount of alkali metal and alkaline earth metal attachment per surface area X (mg / m) obtained by extraction with pure water and ion chromatography is 0.90 parts by mass or less. 2 ) and the total mass ratio k of SiO2, B2O3, and P2O5 in the glass composition are expressed by the following formula: X [mg / m 2 ] > (1.5[mg / m 2 ])×k The present invention is characterized in that:

[0055] For glass fibers, the total amount of one or more components selected from the group consisting of SiO2, B2O3, and P2O5, the alkali metal ion content, and the total coating amount X (mg / m 2 The preferred range of the relationship between the total mass ratio k and the total mass ratio x (mg / m) may be the same as that described for the glass cloth. In particular, the total amount of alkali metals and alkaline earth metals attached per surface area of ​​the glass fiber, X (mg / m), extracted from the surface of the glass fiber with pure water and determined by ion chromatography, 2 ) and the total mass ratio k of SiO2, B2O3, and P2O5 in the glass composition are expressed by the following formula: X [mg / m 2 ] < (15.0[mg / m 2 ])×k It is preferable that the relationship expressed by the following formula be further satisfied.

[0056] <Physical properties> From the viewpoint of large-capacity, high-speed data communication and signal processing, the dielectric constant of the glass cloth according to this embodiment is preferably less than 5.0 at a frequency of 10 GHz, more preferably 4.9 or less or 4.8 or less, and even more preferably 4.7 or less, 4.5 or less, 4.4 or less, 4.0 or less, or 3.7 or less.

[0057] The breaking strength of the glass cloth according to this embodiment is preferably 180 N / mm from the viewpoint of suppressing fluffing of the glass cloth. 2 More preferably, it is 200N / mm 2 More preferably, it is 220 N / mm 2 That's all.

[0058] <Glass cloth manufacturing method> The method for producing the glass cloth according to the present embodiment is not particularly limited, but may include, for example, a method including a weaving step of weaving glass yarns to obtain a glass cloth, a spreading step of spreading the glass yarns of the glass cloth, and a desizing step of removing a sizing agent (also known as a sizing agent) adhering to the glass yarns of the glass cloth. If necessary, the method may also include a surface treatment step using a surface treatment agent such as a silane coupling agent.

[0059] The weaving method is not particularly limited as long as it folds the warp and weft yarns to form a predetermined woven structure. The opening method is not particularly limited, and examples thereof include opening methods using spray water (high-pressure water opening), a vibro washer, ultrasonic water, a mangle, etc.

[0060] Furthermore, the desizing method is not particularly limited, but examples thereof include a method of removing the sizing agent by heating. Note that the sizing agent is used for the purpose of protecting the glass yarn from breakage during the weaving process, etc. Examples of such sizing agents include, but are not particularly limited to, starch-based binders and polyvinyl alcohol-based binders. Note that the temperature at which the sizing agent is removed by heating is preferably 300°C to 500°C, more preferably 330°C to 450°C, and even more preferably 350°C to 430°C, from the viewpoint of sufficiently removing the sizing agent while maintaining the breaking strength.

[0061] Regarding the conditions for heat removal, the CIE L * a * b * Color system chrominance coordinate b * For the purpose of adjusting the temperature, a temperature higher than the above temperature range may be used, and the temperature is preferably 500 to 800°C, more preferably 550 to 750°C, and even more preferably 600 to 700°C.

[0062] When a batch-type heat cleaning method is used for the thermal removal, the heating time is preferably 6 to 66 hours, more preferably 10 to 50 hours, and even more preferably 15 to 45 hours. * If the value is larger than the desired range, * The value is smaller than the desired range.

[0063] More preferably, b *From the viewpoint of controlling the value, a batch type heat cleaning method in which processing is carried out for a long period of time is preferred over a continuous heat cleaning method in which a roll of glass fiber fabric is unwound and continuously passed through a heating furnace, and processing is carried out for a short period of time.

[0064] Further, examples of the surface treatment method include a method in which a surface treatment agent containing a surface treatment agent (e.g., a silane coupling agent) is brought into contact with the glass cloth and then dried. Examples of the contact of the surface treatment agent with the glass cloth include a method in which the glass cloth is immersed in the surface treatment agent, or a method in which the surface treatment agent is applied to the glass cloth using a roll coater, a die coater, a gravure coater, or the like. The method for drying the surface treatment agent is not particularly limited, and examples thereof include a drying method using hot air or electromagnetic waves.

[0065] <Prepreg> The prepreg according to this embodiment includes the glass cloth described above and a matrix resin composition impregnated into the glass cloth. Prepregs containing the glass cloth have improved insulation reliability and a high yield of final products. Furthermore, because they have excellent dielectric properties and moisture absorption resistance, they can provide printed wiring boards with minimal fluctuations in dielectric constant due to the influence of the usage environment, particularly in high-humidity environments.

[0066] The prepreg according to the present embodiment can be produced by a conventional method, for example, by impregnating the glass cloth according to the present embodiment with a varnish prepared by diluting a matrix resin such as an epoxy resin with an organic solvent, volatilizing the organic solvent in a drying oven, and curing the thermosetting resin to a B-stage state (semi-cured state).

[0067] Examples of the matrix resin composition include, in addition to the above-mentioned epoxy resins, thermosetting resins such as bismaleimide resins, cyanate ester resins, unsaturated polyester resins, polyimide resins, BT resins, and functionalized polyphenylene ether resins; thermoplastic resins such as polyphenylene ether resins, polyetherimide resins, wholly aromatic polyester liquid crystal polymers (LCPs), polybutadiene, and fluororesins; and mixed resins thereof. From the viewpoint of improving dielectric properties, reliability, solvent resistance, and press moldability, a resin obtained by modifying a thermoplastic resin with a thermosetting resin may be used as the matrix resin composition.

[0068] The matrix resin composition may also contain inorganic fillers such as silica and aluminum hydroxide; flame retardants such as bromine-based, phosphorus-based, and metal hydroxides; other silane coupling agents; heat stabilizers; antistatic agents; ultraviolet absorbers; pigments; colorants; lubricants; etc.

[0069] <Printed wiring board> The printed wiring board according to this embodiment includes the glass cloth described above and a cured product of the matrix resin impregnated into the glass cloth. The printed wiring board according to this embodiment not only has improved reliability, but also increases the yield of the final product, has excellent dielectric properties, and is adaptable to the usage environment. [Example]

[0070] EXAMPLES The present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples in any way.

[0071] Example 1 Glass yarns (average filament diameter: 7.0 μm, number of filaments: 200) having the composition shown in Table 2, Glass Type: A, were woven using an air jet loom to obtain a glass cloth with a warp and weft placement density of 60 / inch and 58 / inch, respectively, and a thickness of 91 μm. Next, a heat cleaning treatment was performed by heating at 530°C for 12 hours, and a fiber-opening process was carried out using a high-pressure water spray, obtaining a glass cloth intermediate with a width of 1285 mm and a length of 2000 m. The intermediate was then surface-treated with a silane coupling agent to produce a glass cloth.

[0072] <Example 2> A glass cloth was obtained in the same manner as in Example 1, except that the conditions for the heat cleaning treatment were changed to 630° C. and 24 hours.

[0073] <Examples 3 to 5> Glass yarns (average filament diameter: 7.0 μm, number of filaments: 200) having the composition shown in Table 2, Glass Type: A, were woven using an air jet loom to obtain glass cloth with warp and weft thread densities of 60 / inch and 58 / inch, respectively, and a thickness of 91 μm. Next, an aqueous solution of sodium bicarbonate (NaHCO3) dissolved in water was applied to the glass cloth using a two-fluid nozzle. After hot air drying, the amounts of compounds listed in Table 1 were extracted from the glass cloth. Next, a heat cleaning treatment was performed by heating at 400°C for 24 hours, and a fiber-opening process was carried out using a high-pressure water spray, obtaining a glass cloth intermediate with a width of 1285 mm and a length of 2000 m. Finally, the intermediate was surface-treated with a silane coupling agent to produce glass cloth.

[0074] Example 6 Table 2 Glass cloth was produced in the same manner as in Example 1, except that glass type B was used and the heat cleaning time was 24 hours.

[0075] Example 7 Table 2 Glass type: A glass cloth was produced in the same manner as in Example 2, except that B was used.

[0076] <Examples 8 to 10> Table 2 Glass type: Glass cloth was produced in the same manner as in Examples 3 to 5, except that B was used.

[0077] <Comparative Example 1> A glass cloth was obtained in the same manner as in Example 1, except that the temperature conditions of the heat cleaning treatment were changed to 400° C. and the time conditions were changed to 24 hours.

[0078] <Comparative Example 2> A glass cloth was obtained in the same manner as in Example 6, except that the temperature condition of the heat cleaning treatment was changed to 400°C.

[0079] <Comparative Example 3> A continuous heat cleaning method was used for the heat cleaning treatment, and glass cloth was obtained in the same manner as in Example 1, except that heating was performed at 540°C for 90 seconds and then at 650°C for 80 seconds.

[0080] <Comparative Example 4> A continuous heat cleaning method was used for the heat cleaning treatment, and glass cloth was obtained in the same manner as in Example 6, except that heating was performed at 540°C for 90 seconds and then at 650°C for 80 seconds.

[0081] <Physical properties of glass cloth> The physical properties of the glass cloth, specifically, the thickness of the glass cloth, the diameter of the filaments constituting the warp and weft, the number of filaments, and the weaving density of the warp and weft (weave density) were measured in accordance with JIS R3420.

[0082] <Glass yarn composition> The composition of the glass fiber was measured by ICP atomic emission spectroscopy. Specifically, the Si content and B content were measured by melting a weighed glass cloth sample with sodium carbonate, dissolving it in dilute nitric acid, and measuring the resulting sample by ICP atomic emission spectroscopy. The Al content, Ca content, P content, Ti content, and Mg content were measured by thermally decomposing a weighed glass cloth sample with sulfuric acid, nitric acid, and hydrogen fluoride, dissolving it in dilute nitric acid, and measuring the resulting sample by ICP atomic emission spectroscopy. The ICP atomic emission spectroscopy analyzer used was a PS3520VDD II manufactured by Hitachi High-Tech Science Corporation.

[0083] <CIE L * a * b * Color system> Using a spectrophotometer (CM-2600d, manufactured by Konica Minolta), the L of the glass cloth was measured according to JIS Z8781 (2005). * a * b * The color system was measured. * The value was measured by overlapping the glass cloth to a thickness of 2.0 mm or more on a white plate serving as a reference (control), and the average value of five measurements was calculated.

[0084] <Dielectric constant> As described below, a substrate was prepared so that the resin content per 100% by mass of prepreg was 60% by 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). The dielectric constant of the glass cloth was calculated from the obtained substrate dielectric constant based on the volume fraction of the glass cloth and the resin dielectric constant of 2.5.

[0085] <Amount of eluted alkali metals and alkaline earth metals> 1.42 parts by mass of glass cloth was completely immersed (entirely submerged) in 100 parts by mass of distilled water at room temperature (25°C) and left for 5 hours. After leaving the water (a solution from which surface deposits had been dissolved) was measured using an ion chromatograph (manufactured by Nippon Dionex) to obtain the amount of alkali metal ions and alkaline earth metal ions eluted from the glass cloth. A blank was measured using distilled water only. From the obtained measurements, the amount of adhesion per surface area of ​​the glass cloth was calculated based on the average diameter and number of filaments of the filaments.

[0086] <How to manufacture laminates> The glass cloth obtained in the above Examples and Comparative Examples was impregnated with epoxy resin varnish (a mixture of 40 parts by mass of low-brominated bisphenol A epoxy resin, 10 parts by mass of o-cresol novolac epoxy resin, 50 parts by mass of dimethylformamide, 1 part by mass of dicyandiamide, and 0.1 parts by mass of 2-ethyl-4-methylimidazole), and dried at 160°C for 2 minutes to obtain a prepreg. This prepreg was then stacked, and 12 μm thick copper foil was placed on top and bottom, followed by heating at 180°C and 40 kg / cm. 2 The mixture was heated and pressed at 100° C. for 60 minutes to obtain a laminate.

[0087] <Method for evaluating the insulation reliability of laminates> A 1.0 mm thick laminate was prepared as described above, and a wiring pattern with through-holes spaced 0.30 mm apart was created on the copper foil on both sides of the laminate to obtain a sample for evaluation of insulation reliability. A voltage of 50 V was applied to the resulting sample in an atmosphere of 85°C and 85% RH, and the change in resistance value was measured. A resistance of less than 1 MΩ within 500 hours after the start of the test was counted as an insulation failure. Similar measurements were performed on 10 samples, and the percentage of samples that did not exhibit insulation failure was calculated.

[0088] <Breaking strength measurement> The amount of elongation when tension was applied to the glass cloth in the warp or weft direction was measured according to the method described in JIS R3420, General Test Method for Glass Testing, Section 7.4.2 (for cloth).

[0089] As is clear from the results in Table 3, the chrominance coordinate b * The laminates made from the low dielectric glass cloths with the adjusted composition exhibited higher reliability than the comparative examples. In particular, the low dielectric glass cloths coated with alkali metals or alkaline earth metals in Examples 3 to 5 and Examples 8 to 10 exhibited the best reliability.

[0090] [Table 1]

[0091] [Table 2]

[0092] [Table 3]

Claims

1. A glass cloth is made up of glass yarns consisting of a plurality of glass filaments as warp and weft yarns, and the glass filaments contain SiO ２ , B ２ O ３ , and P ２ O ５ The total amount of these components is 71 parts by mass or more and 100 parts by mass or less per 100 parts by mass of all glass composition components, and ＊ a ＊ b ＊ Chrominance coordinate b in the color system ＊ is less than 3.

9.

2. The chrominance coordinate b ＊ But, b ＊ The glass cloth according to claim 1, wherein the viscosity of the glass cloth is less than 3.

6.

3. The chrominance coordinate b ＊ But, b ＊ The glass cloth according to claim 1, wherein the tensile strength is less than 3.

3.

4. The chrominance coordinate b ＊ The glass cloth according to any one of claims 1 to 3, wherein the tensile strength is greater than 2.

0.

5. An alkali metal or alkaline earth metal is attached to the surface of the glass cloth, and the alkali metal and the alkaline earth metal are extracted with pure water and measured by ion chromatography to determine the total attached amount X (mg / m) of the alkali metal and the alkaline earth metal per surface area. ２ ) and SiO in the glass composition ２ , B ２ O ３ , and P ２ O ５ and the total mass ratio k is expressed by the following formula: X[mg / m ２ ] > (1.5[mg / m ２ ])×k The glass cloth according to any one of claims 1 to 4, which satisfies the above.

6. Said 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 claim 5, which satisfies the above formula.

7. The glass cloth according to any one of claims 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 per 100 parts by mass of all glass composition components.

8. The glass cloth according to any one of claims 1 to 7, a matrix resin impregnated in the glass cloth; A prepreg comprising:

9. The glass cloth according to any one of claims 1 to 7, a cured product of the matrix resin impregnated into the glass cloth; A printed wiring board comprising:

10. A glass thread consisting of a plurality of glass filaments, wherein the glass filaments contain SiO in the glass composition. ２ , B ２ O ３ , and P ２ O ５ the total amount of these components is 71 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of all the glass composition components, 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 all the glass composition components, alkali metals or alkaline earth metals are attached to the surface of the glass yarn, and the total amount of attachment of alkali metals and alkaline earth metals per surface area X (mg / m) is determined by ion chromatography after extraction with pure water. ２ ) and SiO in the glass composition ２ , B ２ O ３ , and P ２ O ５ and the total mass ratio k is expressed by the following formula: X[mg / m ２ ] > (1.5[mg / m ２ ])×k Meet the glass thread.

11. Said 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 thread according to claim 10, which satisfies the above.