Glass cloth, prepreg, and printed wiring board

Abstract

Glass cloth, prepreg, and printed wiring board. The present invention aims to provide a glass cloth which, although low in mass, is wound without wrinkles at a high speed, thereby having a high productivity, and a prepreg and a printed wiring board using the same. A glass cloth which is a glass cloth woven with a plurality of glass filaments as warp and weft, the mass of the glass cloth being 11.5 g / m 2 Hereinafter, and (i) the bending stiffness Bw of the warp of the glass cloth is in the range of 0.0030-0.0080 gf-cm 2 / cm, and the bending stiffness Bf of the weft of the glass cloth is in the range of 0.0020-0.0050 gf-cm 2 / cm; or (ii) the average number of segments of the glass cloth is in the range of 3.0-5.0, the opening degree of the warp of the glass cloth is 0.55-0.90, and the opening degree of the weft is 0.65-0.97.

Description

Technical Field

[0001] This invention relates to glass cloth, prepreg, and printed wiring boards. Background Technology

[0002] In recent years, with the miniaturization of electronic instruments, there has been a strong demand for lightweight printed circuit boards (PCBs). In order to achieve low-weight materials used in PCBs, the glass cloth contained in the prepreg is also required to be of low weight.

[0003] Methods for suppressing pinholes in prepregs using low-quality glass cloth have been reported (Patent Documents 1-4). Any of Patent Documents 1-4 suppresses pinholes in the prepreg by controlling the open fiber density or the gap between the filaments of the glass cloth. Furthermore, Patent Document 5 reports a method for reducing warpage in printed wiring boards using low-quality glass cloth. Additionally, Patent Document 6 discloses a method for exhibiting excellent dimensional stability and mechanical properties even in printed wiring boards using low-quality glass cloth by controlling the surface glass fiber coverage.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 6818278

[0007] Patent Document 2: Japanese Patent No. 5905150

[0008] Patent Document 3: Japanese Patent No. 6020764

[0009] Patent Document 4: Japanese Patent No. 6536764

[0010] Patent Document 5: Japanese Patent No. 6421755

[0011] Patent Document 6: Japanese Patent No. 4446754 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] Low-quality glass cloth and prepregs, due to their thinness, are prone to wrinkling during roll-to-roll processing. While Patent Document 1 reports methods that suppress pinholes in the prepreg and wrinkles (longitudinal wrinkles) that extend mechanically during manufacturing, there is still room for improvement in suppressing wrinkles during glass cloth transport. Therefore, the object of this invention is to provide a glass cloth that can be wound without wrinkling even when transporting low-quality glass cloth at high speed, thereby achieving high productivity; a prepreg using the same; and a printed wiring board.

[0014] Solution for solving the problem

[0015] In order to solve the aforementioned problems, the inventors conducted research and found that the lower the quality of the glass cloth and the thinner it is, the more prone it is to wrinkling when transported in roll-to-roll. This is believed to be because, as shown in the following formula, bending stiffness is highly dependent on thickness; the thinner the cloth, the lower the stiffness, and therefore the more prone it is to wrinkling (bending).

[0016] Bending stiffness = Et w 3 W / 12

[0017] In the formula, E: Young's modulus of the mesh.

[0018] t w : thickness of the mesh

[0019] W: Width of the mesh

[0020] Therefore, the inventors discovered that by controlling the bending stiffness of thin, wrinkle-prone glass cloth, pinholes are suppressed during the formation of prepreg, while simultaneously enabling winding without wrinkles during transport; and by reducing the open fiber density of the glass cloth to a level that prevents pinholes during prepreg formation, the thickness of glass cloth of the same quality is increased, enabling winding without wrinkles during transport. A portion of the embodiments of the invention are illustrated below.

[0021] [1] A type of glass cloth, which is woven from glass filaments formed by multiple long glass filaments as warp and weft threads, wherein the mass of the aforementioned glass cloth is 11.5 g / m. 2 The bending stiffness Bw of the warp yarns of the aforementioned glass cloth is between 0.0030 and 0.0080 gf·cm. 2 The bending stiffness Bf of the weft yarn of the aforementioned glass cloth is within the range of / cm, and the bending stiffness Bf of the weft yarn is between 0.0020 and 0.0050 gf·cm. 2 Within the range of / cm.

[0022] [2] The glass cloth according to Project 1, wherein the bending stiffness ratio Bw / Bf of the warp and weft of the aforementioned glass cloth is less than 1.9.

[0023] [3] A type of glass cloth, which is woven from glass filaments formed by multiple long glass filaments as warp and weft threads, wherein the mass of the aforementioned glass cloth is 11.5 g / m. 2 The average number of segments of the aforementioned glass cloth is in the range of 3.0 to 5.0, and the open fiber density of the warp yarns of the aforementioned glass cloth is 0.55 to 0.90 and the open fiber density of the weft yarns is 0.65 to 0.97.

[0024] [4] The glass cloth according to item 3, wherein the average open fiber degree shown as the average of the open fiber degree of the aforementioned warp yarn and the open fiber degree of the aforementioned weft yarn is in the range of 0.60 to 0.93.

[0025] [5] The glass cloth according to any one of items 1 to 4 is composed of warp and weft yarns, which are made of 10 to 50 glass filaments having a diameter in the range of 2.5 μm to 4.0 μm, wherein the fabric density of the aforementioned warp yarns is in the range of 85 to 150 yarns / inch and the fabric density of the aforementioned weft yarns is in the range of 85 to 150 yarns / inch.

[0026] [6] The glass cloth according to any one of items 1 to 5, wherein the thickness of the aforementioned glass cloth is in the range of 8 μm to 18 μm.

[0027] [7] The glass cloth according to any one of items 1 to 6 has been surface treated with a silane coupling agent.

[0028] [8] The glass cloth according to item 7, wherein the aforementioned silane coupling agent contains a silane coupling agent represented by the following general formula (1).

[0029] X(R) 3-n SiY n (1)

[0030] In general formula (1), X is an organic functional group having one or more amino groups, an organic functional group containing one or more unsaturated double bonds that are reactive with free radicals, or an organic functional group containing one or more amino groups and one or more unsaturated double bonds that are reactive with free radicals, Y is each independently an alkoxy group, n is an integer of 1 or more and 3 or less, and R is each independently a group selected from the group consisting of methyl, ethyl and phenyl.

[0031] [9] A prepreg, characterized in that it contains glass cloth, thermosetting resin and inorganic filler as described in any one of items 1 to 8.

[0032]

[10] A printed wiring board, characterized in that it comprises the prepreg described in item 9.

[0033]

[11] An integrated circuit, characterized in that it comprises the printed wiring board described in item 10.

[0034]

[12] An electronic instrument, characterized in that it comprises the printed wiring board described in item 10.

[0035] The effects of the invention

[0036] According to the present invention, a low-quality glass cloth that suppresses wrinkle formation during transport and exhibits high productivity can be provided, as well as a prepreg using the glass cloth and a printed wiring board. Detailed Implementation

[0037] The embodiments of the present invention (hereinafter referred to as "this embodiment") will be described in detail below. However, the present invention is not limited to this embodiment, and various modifications can be made without departing from the spirit of the present invention.

[0038] [Glass cloth]

[0039] The glass cloth in this embodiment is woven from glass fibers formed by multiple long glass filaments as warp and weft yarns. Preferably, the glass cloth has undergone surface treatment using a surface treatment agent described later.

[0040] [Types of Glass]

[0041] The glass cloth used in laminates is typically made of glass known as E-glass (alkali-free glass), but in this embodiment, glass cloth can also be made of, for example, L-glass, NE-glass, D-glass, L2-glass, S-glass, T-glass, silica glass, quartz glass, etc. From the viewpoint of dielectric properties, L-glass, L2-glass, silica glass, quartz glass, etc., are more preferred, among which silica glass and quartz glass are particularly preferred. Furthermore, from the viewpoint of improving the dimensional stability of the laminate containing the glass cloth, S-glass, T-glass, silica glass, quartz glass, etc., are more preferred, among which silica glass and quartz glass are particularly preferred.

[0042] [Properties / Composition of Fiberglass Cloth]

[0043] In this embodiment, the mass of the glass cloth, according to JIS R3420, is 11.5 g / m². 2 From the viewpoint of thinning prepregs containing glass cloth or printed wiring substrates, 11.3 g / m² is preferred. 2 The following, more preferably 11.0 g / m 2 The following is a further preferred option: 10.5 g / m 2The following is a preferred option: 10.0 g / m 2 The following should be noted: There is no specific limit to the lower limit of the mass per unit area of ​​the glass cloth; for example, it can exceed 0 g / m². 2 0.1g / m 2 The above, etc.

[0044] To set the mass of the glass cloth to 11.5 g / m 2 Hereinafter, the glass filaments used in the warp and weft of the glass cloth are preferably fine. In this embodiment, the diameter of the glass filaments is preferably in the range of 2.5 μm to 4.0 μm, more preferably 2.8 μm to 3.9 μm, further preferably 3.0 μm to 3.8 μm, and particularly preferably 3.1 μm to 3.7 μm. If the filament diameter is less than 2.5 μm, the breaking strength of the filament decreases, thus making it prone to fuzzing. Furthermore, if the filament diameter exceeds 4.0 μm, it becomes difficult to set the mass of the glass cloth to 11.5 g / m³. 2 the following.

[0045] In this embodiment, the average number of segments in the glass cloth is in the range of 3.0 to 5.0, preferably in the range of 3.2 to 4.7, more preferably in the range of 3.4 to 4.4, even more preferably in the range of 3.5 to 4.1, and particularly preferably in the range of 3.6 to 4.0. When the average number of segments is less than 3.0, the thickness of the glass cloth becomes thinner, and therefore wrinkles are easily formed during the handling of the glass cloth. On the other hand, if the average number of segments exceeds 5.0, the pinhole formation rate of the prepreg increases. By keeping the average number of segments in the glass cloth within the above range, both the suppression of wrinkles during the handling of the glass cloth and the suppression of pinholes in the prepreg can be achieved.

[0046] In this embodiment, the openness of the warp yarns of the glass cloth is in the range of 0.55 to 0.90, and the openness of the weft yarns is in the range of 0.65 to 0.97; preferably, the openness of the warp yarns is in the range of 0.60 to 0.89, and the openness of the weft yarns is in the range of 0.70 to 0.96; more preferably, the openness of the warp yarns is in the range of 0.65 to 0.88, and the openness of the weft yarns is in the range of 0.75 to 0.95; even more preferably, the openness of the warp yarns is in the range of 0.67 to 0.87, and the openness of the weft yarns is in the range of 0.77 to 0.94; particularly preferably, the openness of the warp yarns is in the range of 0.68 to 0.86, and the openness of the weft yarns is in the range of 0.78 to 0.93. By ensuring that the openness of the warp and weft yarns of the glass cloth is within the above ranges, both wrinkle suppression during glass cloth handling and pinhole suppression of the prepreg can be achieved. If the open fiber size exceeds the upper limit of the above-mentioned range, the open fiber size is too high, which makes it easy for wrinkles to form during the handling of the glass cloth. On the other hand, if the open fiber size is below the lower limit of the above-mentioned range, the pinhole rate during prepreg production will increase.

[0047] Furthermore, the average open fiber density of the glass cloth in this embodiment is preferably in the range of 0.60 to 0.93, more preferably in the range of 0.62 to 0.93, even more preferably in the range of 0.64 to 0.92, even more preferably in the range of 0.66 to 0.92, and particularly preferably in the range of 0.67 to 0.91. By ensuring that the average open fiber density of the glass cloth is within the above range, both wrinkle suppression during glass cloth handling and pinhole suppression of the prepreg can be achieved. It should be noted that the average open fiber density of the glass cloth is shown as the average of the open fiber density of the warp yarns and the open fiber density of the weft yarns.

[0048] Furthermore, in this embodiment, the number of glass filaments used in the warp and weft of the glass cloth is preferably in the range of 10 to 50, more preferably in the range of 15 to 45, even more preferably in the range of 20 to 43, and particularly preferably in the range of 25 to 40. If the number of filaments exceeds 50, the widening rate may be insufficient during flattening processes such as fiber opening of the glass cloth. In addition, if the number of filaments is less than 10, the glass cloth is prone to pilling. Glass filaments within the above-mentioned range can be bundled during the formation of the glass filaments.

[0049] From the viewpoint that the invention is within the scope of significantly demonstrating its effects, it is preferable that the fabric density of the warp yarns of the glass cloth in this embodiment is in the range of 85 to 150 threads / inch and the fabric density of the weft yarns is in the range of 85 to 150 threads / inch, more preferably in the range of 88 to 140 threads / inch, further preferably in the range of 90 to 135 threads / inch, and particularly preferably in the range of 95 to 130 threads / inch.

[0050] In this embodiment, the thickness of the glass cloth is preferably in the range of 8μm to 18μm, more preferably 9μm to 17μm, even more preferably 9μm to 16μm, even more preferably 9μm to 15μm, and particularly preferably 10μm to 15μm. If the thickness of the glass cloth is less than 8μm, the toughness of the glass cloth is lost, and wrinkles are easily generated during handling. In addition, if the thickness of the glass cloth exceeds 18μm, the widening ratio of the glass cloth is insufficient, and pinholes are easily generated in the prepreg.

[0051] [Surface treatment agent (silane coupling agent)]

[0052] The glass fibers (including glass filaments) constituting the glass cloth are preferably surface-treated with a surface treatment agent such as a silane coupling agent. As a silane coupling agent, for example, the silane coupling agent shown in the following general formula (1) is preferably used.

[0053] X(R) 3-n SiY n (1)

[0054] {In formula (1), X is an organic functional group having one or more amino groups, an organic functional group containing one or more unsaturated double bonds with free radical reactivity, or an organic functional group containing both one or more amino groups and one or more unsaturated double bonds with free radical reactivity; Y is each independently an alkoxy group; n is an integer of 1 to 3; and R is each independently a group selected from the group consisting of methyl, ethyl, and phenyl.}

[0055] In the above general formula (1), X can be, for example, an organic functional group containing at least one radical-reactive carbon-carbon double bond or other radical-reactive unsaturated double bond group, an organic functional group having at least one amino group, or an organic functional group containing both at least one radical-reactive unsaturated double bond group and at least one amino group. The amino group can be, for example, a primary amino group, a secondary amino group, a tertiary amino group, or a quaternary ammonium salt. As for Y in the above general formula (1), any form of alkoxy group can be used, but in order to achieve the stabilization of the glass cloth, an alkoxy group with 5 or fewer carbon atoms is preferred.

[0056] As a surface treatment agent, the silane coupling agent shown in general formula (1) can be used alone or in combination of two or more silane coupling agents of different X values ​​in general formula (1). Examples of silane coupling agents shown in general formula (1) include, for example, 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. Alkane and its hydrochloride salt, N-β-(N-benzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride salt, N-β-(N-benzylaminoethyl)-γ-aminopropyltriethoxysilane and its hydrochloride salt, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropyltriethoxysilane, aminopropyltrimethoxysilane, vinyltrimethoxysilane, methacryloyloxypropyltrimethoxysilane, acryloyloxypropyltrimethoxysilane and other known single silane coupling agents, or mixtures thereof.

[0057] The surface treatment method for the glass cloth in this embodiment is not particularly limited, and examples include: a covering step in which the surface of the glass filament is covered with a silane coupling agent using a treatment solution containing a silane coupling agent; and an adhesion step in which the silane coupling agent is bonded to the surface of the glass filament by heating and drying. The treatment solution preferably contains 0.1% to 3.0% by weight of the silane coupling agent. Preferably, the surface of the glass filament is substantially completely covered by the silane coupling agent using the covering step.

[0058] As a method for coating the treatment solution onto glass cloth, it is possible to use (i) immerse the glass cloth in the treatment solution in a bath and pass it through (hereinafter referred to as "immersion method"); or (ii) directly coat the glass cloth with the treatment solution using a roller coater, die coater, or gravure coater. In the case of coating by the immersion method described above (i), it is preferable to select an immersion time of the glass cloth in the treatment solution of 0.5 seconds or more and 1 minute or less.

[0059] The heating and drying temperature is preferably 90°C or higher to ensure sufficient reaction between the silane coupling agent and the glass, and is more preferably 100°C or higher. Furthermore, to prevent the degradation of the organic functional groups in the silane coupling agent, the heating and drying temperature is preferably 300°C or lower, and is more preferably 200°C or lower.

[0060] The surface treatment method for glass cloth in this embodiment may include an adjustment step of adjusting the amount of silane coupling agent adhering to the surface of glass filaments by washing at least a portion of the silane coupling agent with a washing liquid such as water. Washing can be performed using high-pressure water spray or the like.

[0061] As a solvent for dissolving or dispersing the silane coupling agent, either water or an organic solvent can be used. From the perspective of safety and environmental protection, water is preferred as the main solvent. As a method for obtaining a treatment solution with water as the main solvent, the preferred methods are either directly adding the silane coupling agent to the water, or dissolving the silane coupling agent in a water-soluble organic solvent to form an organic solvent solution, and then adding that organic solvent solution to the water. Surfactants can also be used in combination to improve the water dispersibility or stability of the silane coupling agent in the treatment solution.

[0062] The aforementioned covering, bonding, and adjusting processes are preferably performed on the glass cloth after the weaving process. Furthermore, if necessary, a fiber-opening process can be performed after the weaving process to open the glass filaments of the glass cloth. It should be noted that when the adjusting process is performed after the weaving process, the adjusting process can also serve as the fiber-opening process. It should be noted that the composition of the glass cloth generally does not change before and after fiber opening. It is believed that through the above manufacturing method, a silane coupling agent layer can be formed substantially completely and uniformly on the surface of each individual glass filament constituting the glass filaments.

[0063] [Fiber Opening Process]

[0064] There are no particular limitations on the fiber-opening process for glass cloth, and examples include methods such as using water spray (high-pressure water fiber opening), vibrating washing machines, ultrasonic water, and liquid rolling mills to open the fiber. During this fiber-opening process, there is a tendency to narrow the fiber width of the glass cloth by increasing the tension applied to it, and to widen the fiber width by decreasing the tension. It should be noted that, in order to suppress the decrease in tensile strength of the glass cloth caused by the fiber-opening process, it is preferable to implement measures such as reducing friction of the contact components during the weaving of the glass fibers, or optimizing the sizing agent and increasing its adhesion.

[0065] The water pressure for high-pressure water splitting of the glass cloth in this embodiment is preferably 0.13 MPa or less, more preferably 0.12 MPa or less, even more preferably 0.11 MPa or less, and even more preferably 0.10 MPa or less. If the water pressure for high-pressure water splitting exceeds 0.13 MPa, the fiber width of the glass cloth will become wider and wrinkles cannot be suppressed during high-speed transport.

[0066] Furthermore, during the fiber opening process, there is a tendency to narrow the fiber width of the glass cloth by increasing the tension applied to it, and conversely, to widen the fiber width by decreasing the tension. The tension applied to the glass cloth in the longitudinal direction in this embodiment is preferably 50 N or more, more preferably 60 N or more, further preferably 70 N or more, and even more preferably 80 N or more, relative to a 1300 mm wide glass cloth. There is no particular limitation on the upper limit of the tension applied to the glass cloth in the longitudinal direction if it is within a range that will not cause breakage or wrinkling of the glass cloth. If the tension in the longitudinal direction is less than 50 N, the fiber width of the glass cloth tends to widen, and wrinkling during high-speed transport cannot be suppressed.

[0067] [Bending Stiffness]

[0068] In this embodiment, it was found that because lower quality glass cloth is thinner, it is more prone to wrinkling during roll-to-roll transport. This is believed to be because, as shown in the following formula, bending stiffness is highly dependent on thickness; the thinner the cloth, the lower the stiffness, thus making it easier to wrinkle (bending phenomenon).

[0069] Bending stiffness = Et w 3 W / 12

[0070] In the formula, E: Young's modulus of the mesh.

[0071] t w : thickness of the mesh

[0072] W: Width of the mesh

[0073] As mentioned above, the bending stiffness of glass cloth depends heavily on its thickness. Therefore, the bending stiffness can be controlled by adjusting the width of the warp and weft threads. To suppress wrinkling during glass cloth handling, it is preferable to increase the bending stiffness of the glass cloth. Therefore, there is a tendency to narrow the width of the warp and weft threads.

[0074] In this embodiment, the bending stiffness Bw of the warp yarns of the glass cloth is between 0.0030 and 0.0080 gf·cm. 2 Within the range of / cm, the bending stiffness Bf of the weft yarn of the aforementioned glass cloth is between 0.0020 and 0.0050 gf·cm. 2 The range is approximately 0.0032–0.0078 gf·cm. For Bw and Bf, Bw is preferably in the range of 0.0032–0.0078 gf·cm. 2 Within the range of / cm, Bf is between 0.0022 and 0.0048 gf·cm. 2 The range is / cm; more preferably, Bw is in the range of 0.0034 to 0.0076 gf·cm. 2 Within the range of / cm, Bf is between 0.0024 and 0.0046 gf·cm. 2 The range is approximately 0.0035–0.0074 gf·cm; further preferably, Bw is in the range of 0.0035–0.0074 gf·cm. 2 Within the range of / cm, Bf is between 0.0025 and 0.0044 gf·cm. 2 Within the range of / cm; particularly preferred is Bw being 0.0036~0.0070gf·cm. 2 Within the range of / cm, Bf is between 0.0026 and 0.0040 gf·cm. 2 Within the range of / cm. If the bending stiffness is below the lower limit mentioned above, wrinkles are easily formed during the handling of the glass cloth. On the other hand, if the bending stiffness exceeds the upper limit mentioned above, pinholes are easily generated during the prepreg production. Therefore, by controlling the bending stiffness of the thin glass cloth, which is prone to wrinkling, within the numerical range described above, it is possible to suppress the generation of pinholes when the glass cloth is formed into prepreg, and to roll it up without wrinkles during handling.

[0075] Furthermore, if the ratio of the warp stiffness Bw to the weft stiffness Bf exceeds 1.9, there is an excessive difference in the toughness of the warp and weft yarns, which easily leads to wrinkles during the handling of the glass cloth. Therefore, in this embodiment, the warp-to-weft stiffness ratio Bw / Bf of the glass cloth is preferably 1.9 or less, more preferably 1.85 or less, further preferably 1.80 or less, even more preferably 1.75 or less, and particularly preferably 1.70 or less.

[0076] [Prepreg]

[0077] As one aspect of the present invention, the prepreg can be manufactured using conventional methods. For example, after impregnating the glass cloth described above with a thermosetting resin varnish (hereinafter simply referred to as "varnish") prepared by diluting a matrix resin such as epoxy resin with an organic solvent, the organic solvent is evaporated using a drying oven, and the thermosetting resin is cured to stage B (semi-cured state), thus producing the prepreg. It should be noted that the amount of matrix resin adhering to the glass cloth is preferably relative to the total mass of the solids in the varnish and the mass of the glass cloth, with the mass of the solids in the varnish being 20% ​​to 80% by mass.

[0078] Examples of matrix resins used in the prepreg of this invention include epoxy resins, unsaturated polyester resins, polyimide resins, bismaleimide triazine (BT) resins, cyanate ester resins, and other thermosetting resins; polyphenylene oxide (PPO) resins, polyetherimide resins, fluoropolymers, and other thermoplastic resins; or mixtures thereof. Additionally, resins formed by mixing inorganic fillers such as aluminum hydroxide, talc, and silica may also be used.

[0079] In addition, a printed wiring board containing the prepreg as described above is also an aspect of the present invention, which can provide integrated circuits and electronic instruments containing the printed wiring board.

[0080] [Example]

[0081] The present invention will be described in detail below with examples and comparative examples. However, the present invention is not limited to the examples.

[0082] [Properties of Fiberglass Cloth]

[0083] Specifically, the physical properties of glass cloth, including its thickness, the quality of warp and weft yarns, the diameter of the filaments constituting the warp and weft yarns, and the fabric density of the warp and weft yarns, are determined according to JIS R3420.

[0084] [Number of warp and weft filaments]

[0085] The cross-section of the filaments was observed, the number of filaments was counted, and the average value of 5 measurements was obtained.

[0086] [Warp and weft widths of the fiberglass cloth]

[0087] Five glass cloth pieces with dimensions of 70 mm in the warp direction and 70 mm in the weft direction were cut from the glass cloth obtained in the examples and comparative examples and used as test pieces for fiber bundle measurement.

[0088] For the test pieces used for measuring the filament bundle, observation was performed vertically using a macroscope at 100x magnification. The width of 250 warp filaments was randomly measured on each test piece, and the average value of the obtained width of the 250 warp filaments was calculated and taken as the warp filament width.

[0089] Similarly, the width of 250 weft threads was randomly measured on each test piece, and the average value of the width of the 250 weft threads was calculated and taken as the weft thread width.

[0090] [Fiber openness of glass cloth]

[0091] The open fiber density of the warp and weft yarns of the glass cloth is calculated using the following formula.

[0092] Warp fiber opening degree = warp width [μm] ÷ (number of warp filaments × warp filament diameter [μm])

[0093] The opening density of the weft yarn = the width of the weft yarn [μm] ÷ (the number of weft yarn filaments × the diameter of the weft yarn filaments [μm])

[0094] In addition, the average open fiber density of the glass cloth is set as the average of the open fiber density of the warp and weft yarns.

[0095] [Average number of segments in the fiberglass cloth]

[0096] The average number of segments of the glass cloth is calculated using the following formula.

[0097] Average number of segments = thickness of glass cloth [μm] ÷ (average diameter of warp and weft filaments [μm])

[0098] [Flexural stiffness of glass cloth]

[0099] The bending stiffness of the glass cloth was measured five times using a pure bending tester (KATO TECH CO.,LTD., KES-FB2-A) under the following test conditions. The bending stiffness of the warp and weft yarns was calculated using the average of the five measurements. It should be noted that for the bending stiffness, the value at the first bending test was recorded, with a different sample each time, for a total of five measurements.

[0100] <Measurement Conditions>

[0101] Sample width: 10 (cm)

[0102] SENS: 4 (gf)

[0103] Maximum curvature: ±2.5 (1 / cm)

[0104] Bending speed: 0.500 ([1 / cm] / sec)

[0105] The calculated curvature range for bending stiffness is +0.5 to +1.5.

[0106] [Boron content in glass cloth]

[0107] The boron content in the glass cloth was determined using ICP emission spectroscopy. It should be noted that the ICP emission spectrometer used was a PS3520VDDII manufactured by Hitachi High-Tech Science Corporation. Specifically, to determine the boron content, a glass cloth sample was weighed, melted with sodium carbonate, dissolved in dilute nitric acid, and brought to a final volume. The boron content in the sample was then determined using ICP emission spectroscopy.

[0108] [Evaluation of wrinkles caused during the transport of glass cloth]

[0109] A 1300mm wide, 2000m long glass cloth is wound onto a 300mm diameter resin core tube at a conveying speed of 60m / min under the following conditions. Evaluate the formation of wrinkles under these conditions.

[0110] <Coiling Conditions>

[0111] Transport speed = 60m / minute

[0112] Winding tension = 300N

[0113] Tension taper = 40%

[0114] Coiling contact pressure = 30MPa

[0115] Contact pressure taper = 0%

[0116] <Wrinkle Evaluation>

[0117] A: No wrinkles were formed during the winding process.

[0118] B: No more than 2 wrinkles occur during winding.

[0119] C: More than 3 wrinkles occur during winding, or wrinkles occur continuously during winding.

[0120] [Prepreg Preparation Method]

[0121] The prepreg was prepared by mixing 80 parts by weight of low-brominated bisphenol A type epoxy resin, 20 parts by weight of cresol phenolic varnish type epoxy resin, 2 parts by weight of dicyandiamide, 0.2 parts by weight of 2-ethyl-4-methylimidazole, and 100 parts by weight of 2-methoxy-ethanol. The prepreg coating was carried out under the following conditions: the glass cloth was conveyed at a speed of 3 m / min, impregnated in epoxy resin varnish, the gaps were adjusted to a resin content of 68% by weight, excess varnish was scraped off, and drying was carried out at a drying temperature of 170°C for 1 minute and 30 seconds.

[0122] [Pinhole Evaluation of Prepreg]

[0123] Samples of the obtained prepreg were taken in a 400mm × 400mm size. A total of 150 sheets of prepreg in the above size were taken. The number of pinholes was counted by visual inspection. Prepregs with no more than 4 pinholes per sheet were considered qualified. The pass rate of the 150 sheets was evaluated.

[0124] (Example 1)

[0125] As warp yarns, silica glass fibers with an average filament diameter of 3.6 μm, 38 filaments, and a twist of 1.0 Z were used. As weft yarns, silica glass fibers with an average filament diameter of 3.6 μm, 38 filaments, and a twist of 1.0 Z were used. A 1300 mm wide grey fabric of glass cloth was woven using an air-jet loom with a fabric density of 105 warp yarns / inch and 110 weft yarns / inch. The glass cloth, which had undergone heat degreasing at 400°C for 30 hours, was impregnated with a treatment solution containing N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Dow Corning Toray Co., Ltd.; Z6032) dispersed in water, and then subjected to heat drying. Next, it was irradiated in water at a frequency of 25 kHz and an output power of 0.30 W / cm². 2 The fiber opening process was performed using ultrasonic waves (with a warp tension of 90N during the fiber opening process). The resulting fiber-opened glass cloth had a warp width of 104μm and a weft width of 112μm.

[0126] (Example 2)

[0127] Using the fiberglass cloth obtained in Example 1, instead of ultrasonic fiber opening, high-pressure water fiber opening (water pressure: 0.09 MPa, warp tension during fiber opening: 105 N) was performed. Otherwise, the processing was carried out using the same method as in Example 1. The resulting fiberglass cloth after fiber opening had a warp width of 120 μm and a weft width of 130 μm.

[0128] (Example 3)

[0129] Using the glass cloth obtained in Example 1, instead of ultrasonic fiber splitting, high-pressure water splitting (water pressure: 0.05 MPa, warp tension during splitting: 115 N) was used for fiber splitting. Otherwise, the processing was carried out using the same method as in Example 1. The resulting glass cloth after fiber splitting had a warp width of 94 μm and a weft width of 108 μm.

[0130] (Example 4)

[0131] As warp yarns, silica glass yarns with an average filament diameter of 3.5 μm, 40 filaments, and a twist of 1.0 Z were used. As weft yarns, silica glass yarns with an average filament diameter of 3.5 μm, 40 filaments, and a twist of 1.0 Z were used. A 1300 mm wide grey fabric of glass cloth was woven using an air-jet loom with a fabric density of 110 warp yarns / inch and 110 weft yarns / inch. The glass cloth, which had undergone heat degreasing at 400°C for 30 hours, was impregnated in a treatment solution containing N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Dow Corning Toray Co., Ltd.; Z6032) dispersed in water, and then heated and dried. Next, fiber opening was performed using high-pressure water fiber opening (water pressure: 0.05 MPa, warp tension during fiber opening: 100 N). The resulting glass cloth after fiber splitting has a warp width of 100 μm and a weft width of 112 μm.

[0132] (Example 5)

[0133] As warp yarns, silica glass fibers with an average filament diameter of 4.0 μm, 40 filaments, and a twist of 1.0 Z were used. As weft yarns, silica glass fibers with an average filament diameter of 4.0 μm, 40 filaments, and a twist of 1.0 Z were used. A 1300 mm wide grey fabric of glass cloth was woven using an air-jet loom with a fabric density of 96 warp yarns / inch and 96 weft yarns / inch. The glass cloth, which had undergone heat degreasing at 400°C for 30 hours, was impregnated with a treatment solution containing N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Dow Corning Toray Co., Ltd.; Z6032) dispersed in water, and then heated and dried. Next, fiber opening was performed using high-pressure water splitting (water pressure: 0.05 MPa, warp tension during splitting: 90 N). The obtained fiber-opening glass cloth has a warp width of 136μm and a weft width of 150μm.

[0134] (Example 6)

[0135] As warp yarns, E-glass yarns with an average filament diameter of 3.6 μm, 38 filaments, and a twist of 1.0 Z were used. As weft yarns, E-glass yarns with an average filament diameter of 3.6 μm, 38 filaments, and a twist of 1.0 Z were used. A 1300 mm wide grey glass cloth was woven using an air-jet loom with a fabric density of 105 warp yarns / inch and 110 weft yarns / inch. The glass cloth, which had undergone heat degreasing at 400°C for 30 hours, was impregnated in a treatment solution containing N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Dow Corning Toray Co., Ltd.; Z6032) dispersed in water, and then heated and dried. Next, it underwent high-pressure water splitting (water pressure: 0.09 MPa, warp tension during splitting: 95 N). The obtained fiber-opening glass cloth has a warp width of 111 μm and a weft width of 126 μm.

[0136] (Example 7)

[0137] As warp yarns, E-glass yarns with an average filament diameter of 4.0 μm, 40 filaments, and a twist of 1.0 Z were used. As weft yarns, E-glass yarns with an average filament diameter of 4.0 μm, 40 filaments, and a twist of 1.0 Z were used. A 1300 mm wide grey glass cloth was woven using an air-jet loom with a fabric density of 96 warp yarns / inch and 96 weft yarns / inch. The glass cloth, which had undergone heat degreasing at 400°C for 30 hours, was impregnated with a treatment solution containing N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Dow Corning Toray Co., Ltd.; Z6032) dispersed in water, and then heated and dried. Next, it underwent high-pressure water splitting (water pressure: 0.09 MPa, warp tension during splitting: 70 N). The obtained fiber-opening glass cloth has a warp width of 136μm and a weft width of 151μm.

[0138] (Example 8)

[0139] As warp yarns, E-glass yarns with an average filament diameter of 4.0 μm, 40 filaments, and a twist of 1.0 Z were used; as weft yarns, E-glass yarns with an average filament diameter of 4.0 μm, 50 filaments, and a twist of 1.0 Z were used. A 1300 mm wide grey glass cloth was woven using an air-jet loom with a fabric density of 96 warp yarns / inch and 96 weft yarns / inch. The glass cloth, which had undergone heat degreasing at 400°C for 30 hours, was impregnated with a treatment solution containing N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Dow Corning Toray Co., Ltd.; Z6032) dispersed in water, and then heated and dried. Next, it underwent high-pressure water splitting (water pressure: 0.08 MPa, warp tension during splitting: 125 N). The obtained fiber-opening glass cloth has a warp width of 129 μm and a weft width of 179 μm.

[0140] (Example 9)

[0141] As warp yarns, low-dielectric glass (15% boron content) yarns with an average filament diameter of 4.0 μm, 40 filaments, and a twist of 1.0 Z were used. As weft yarns, low-dielectric glass (15% boron content) yarns with an average filament diameter of 4.0 μm, 40 filaments, and a twist of 1.0 Z were used. A 1300 mm wide grey glass cloth was woven using an air-jet loom with a fabric density of 96 warp yarns / inch and 96 weft yarns / inch. The glass cloth, which had undergone heat degreasing at 400°C for 30 hours, was impregnated with a treatment solution containing N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Dow Corning Toray Co., Ltd.; Z6032) dispersed in water, and then heated and dried. Next, it underwent high-pressure water splitting (water pressure: 0.08 MPa, warp tension during splitting: 100 N). The obtained fiber-opening glass cloth has a warp width of 116μm and a weft width of 139μm.

[0142] (Example 10)

[0143] As warp yarns, silica glass fibers with an average filament diameter of 3.6 μm, 38 filaments, and a twist of 1.0 Z were used. As weft yarns, silica glass fibers with an average filament diameter of 3.6 μm, 38 filaments, and a twist of 1.0 Z were used. A 1300 mm wide grey fabric of glass cloth was woven using an air-jet loom with a fabric density of 105 warp yarns / inch and 110 weft yarns / inch. The glass cloth, which had undergone heat degreasing at 400°C for 30 hours, was impregnated with a treatment solution containing N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Dow Corning Toray Co., Ltd.; Z6032) dispersed in water, and then subjected to heat drying. Next, it was irradiated in water at a frequency of 25 kHz and an output power of 0.25 W / cm². 2 The fiber opening process was performed using ultrasonic waves (with a warp tension of 120N during the fiber opening process). The resulting fiber-opened glass cloth had a warp width of 82μm and a weft width of 94μm.

[0144] (Comparative Example 1)

[0145] Instead of ultrasonic fiber opening, high-pressure water fiber opening (water pressure: 0.15 MPa, warp tension during fiber opening: 120 N) was used. Otherwise, the fiber opening process was performed using the same method as in Example 1. The resulting fiber-opened glass cloth had a warp width of 128 μm and a weft width of 139 μm.

[0146] (Comparative Example 2)

[0147] High-pressure water splitting (water pressure: 0.15 MPa, warp tension during splitting: 120 N) was used for splitting, otherwise the same method as in Example 4 was used. The resulting split-processed glass cloth had a warp width of 137 μm and a weft width of 149 μm.

[0148] (Comparative Example 3)

[0149] As the warp yarn, E-glass yarn with an average filament diameter of 3.6 μm, 40 filaments, and a twist of 0.5 Z was used. As the weft yarn, E-glass yarn with an average filament diameter of 3.6 μm, 40 filaments, and a twist of 0.5 Z was used. A 1300 mm wide grey glass cloth was woven using an air-jet loom with a fabric density of 107 warp yarns / inch and 107 weft yarns / inch. After removing the sizing agent by heating at 400°C for 30 hours, the silane coupling agent (S-350: N-vinylbenzyl-aminoethyl-γ-aminopropyltrimethoxysilane (hydrochloride) CHISSO CORPORATION) in the surface treatment agent was adjusted to a concentration of 10 g / L. After pressing with a padder roll, it was dried and cured at 120°C for 1 minute. The glass cloth is processed using a water jet at a pressure of 1.0 MPa. The tension in the warp direction is set to 20 N / m, and while the glass cloth is held at both ends in the weft direction by a tenter frame, a tension of 5–10 N / m is also applied in the weft direction to perform fiber opening treatment, producing glass cloth rolls. The resulting fiber-opened glass cloth has a warp width of 131 μm and a weft width of 161 μm.

[0150] (Comparative Example 4)

[0151] The number of warp and weft filaments is 40 each; the glass type is E glass; the glass cloth is processed by a water flow at a pressure of 0.5 MPa, with the tension in the warp direction set to 20 N / m, and the weft direction tension is also applied at both ends of the glass cloth using a tenter frame to perform the fiber-opening process. Otherwise, the processing is carried out using the same method as Comparative Example 1. The resulting fiber-opened glass cloth has a warp width of 111 μm and a weft width of 144 μm.

[0152] (Comparative Example 5)

[0153] As warp yarns, E-glass yarns with an average filament diameter of 4.0 μm, 50 filaments, and a twist of 1.0 Z were used. As weft yarns, E-glass yarns with an average filament diameter of 4.0 μm, 50 filaments, and a twist of 1.0 Z were used. A 1300 mm wide grey glass cloth was woven using an air-jet loom with a fabric density of 95 warp yarns / inch and 95 weft yarns / inch. The glass cloth, which had undergone heat degreasing at 400°C for 30 hours, was impregnated with a treatment solution containing N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Dow Corning Toray Co., Ltd.; Z6032) dispersed in water, and then heated and dried. Next, it underwent high-pressure water splitting (water pressure: 0.30 MPa, warp tension during splitting: 100 N). The obtained fiber-opening glass cloth has a warp width of 140μm and a weft width of 215μm.

[0154] (Comparative Example 6)

[0155] In fiber opening, instead of using spraying, this method applies a tension of 15N to the weft direction and 20N to the warp direction while simultaneously irradiating the fiber in water at a frequency of 25kHz and an output power of 0.72W / cm. 2 The ultrasonic fiber opening process yielded the same glass cloth product as Comparative Example 5. Here, an expander roll was used as a method to apply tension in the weft direction. The resulting fiber-opened glass cloth had a warp width of 150 μm and a weft width of 125 μm.

[0156] (Comparative Example 7)

[0157] The warp tension during the fiber opening process was set to 20N, and the evaluation glass cloth product was obtained using the same method as in Example 1. The obtained fiber-opened glass cloth had a warp width of 123μm and a weft width of 138μm.

[0158] (Comparative Example 8)

[0159] The warp tension during the fiber-opening process was set to 20N, and the evaluation glass cloth product was obtained using the same method as in Example 2. The obtained glass cloth after fiber-opening had a warp width of 126μm and a weft width of 141μm.

[0160] The measurement and evaluation results are shown in Tables 1 and 2.

[0161] [Table 1]

[0162]

[0163] [Table 2]

[0164]

Claims

1. A type of glass cloth, woven from glass filaments formed by multiple long glass filaments as warp and weft threads, wherein the glass cloth has a mass of 11.5 g / m³. 2 The bending stiffness Bw of the warp yarns of the glass cloth is between 0.0030 and 0.0080 gf·cm. 2 The bending stiffness Bf of the weft yarns of the glass cloth is within the range of / cm, and the bending stiffness Bf of the weft yarns is between 0.0020 and 0.0050 gf·cm. 2 Within the range of / cm, Both the bending stiffness Bw and the bending stiffness Bf were measured using a pure bending test machine.

2. The glass cloth according to claim 1, wherein, The mass of the glass cloth is 11.0 g / m. 2 the following.

3. The glass cloth according to claim 1 or 2, wherein, The mass of the glass cloth is 10.0 g / m. 2 the following.

4. The glass cloth according to claim 1 or 2, wherein, The bending stiffness Bw of the warp yarns of the glass cloth is between 0.0036 and 0.0070 gf·cm. 2 The bending stiffness Bf of the weft yarns of the glass cloth is within the range of / cm, and the bending stiffness Bf of the weft yarns is between 0.0026 and 0.0040 gf·cm. 2 Within the range of / cm.

5. The glass cloth according to claim 1 or 2, wherein, The bending stiffness ratio of the warp and weft yarns of the glass cloth, Bw / Bf, is less than 1.

9.

6. The glass cloth according to claim 1 or 2, wherein, The bending stiffness ratio (Bw / Bf) of the warp and weft yarns of the glass cloth is below 1.

70.

7. A type of glass cloth, woven from glass filaments formed by multiple long glass filaments as warp and weft threads, wherein the glass cloth has a mass of 11.5 g / m³. 2 The average number of segments in the glass cloth is in the range of 3.0 to 5.0, the open fiber density of the warp yarns is 0.55 to 0.90, and the open fiber density of the weft yarns is 0.65 to 0.

97. The bending stiffness Bw of the warp yarns of the glass cloth is between 0.0030 and 0.0080 gf·cm. 2 The bending stiffness Bf of the weft yarns of the glass cloth is within the range of / cm, and the bending stiffness Bf of the weft yarns is between 0.0020 and 0.0050 gf·cm. 2 Within the range of / cm, Both the bending stiffness Bw and the bending stiffness Bf were measured using a pure bending test machine.

8. The glass cloth according to claim 7, wherein, The mass of the glass cloth is 11.0 g / m. 2 the following.

9. The glass cloth according to claim 7 or 8, wherein, The mass of the glass cloth is 10.0 g / m. 2 the following.

10. The glass cloth according to claim 7 or 8, wherein, The average number of segments of the glass cloth is in the range of 3.4 to 4.

4.

11. The glass cloth according to claim 7 or 8, wherein, The average number of segments in the glass cloth is in the range of 3.6 to 4.

0.

12. The glass cloth according to claim 7 or 8, wherein, The fiber openness of the warp yarns of the glass cloth is 0.65 to 0.88, and the fiber openness of the weft yarns is 0.75 to 0.

95.

13. The glass cloth according to claim 7 or 8, wherein, The fiber openness of the warp yarns of the glass cloth is 0.68 to 0.86, and the fiber openness of the weft yarns is 0.78 to 0.

93.

14. The glass cloth according to claim 7 or 8, wherein, The average openness, shown as the average of the openness of the warp and the openness of the weft, is in the range of 0.60 to 0.

93.

15. The glass cloth according to claim 14, wherein, The average openness, shown as the average of the openness of the warp and the openness of the weft, is in the range of 0.64 to 0.

92.

16. The glass cloth according to claim 14, wherein, The average open fiber ratio, shown as the average of the open fiber ratio of the warp and the weft, is in the range of 0.67 to 0.

91.

17. The glass cloth according to claim 1 or 7, comprising warp and weft yarns of 10 to 50 glass filaments having a diameter in the range of 2.5 μm to 4.0 μm, wherein the fabric density of the warp yarns is in the range of 85 to 150 yarns / inch and the fabric density of the weft yarns is in the range of 85 to 150 yarns / inch.

18. The glass cloth according to claim 17, wherein the diameter of the glass filament is 3.1 μm to 3.7 μm.

19. The glass cloth according to claim 17, wherein the number of glass filaments is in the range of 15 to 45.

20. The glass cloth according to claim 17, wherein the number of glass filaments is in the range of 25 to 40.

21. The glass cloth according to claim 17, wherein the fabric density of the warp yarns is in the range of 95 to 130 threads / inch and the fabric density of the weft yarns is in the range of 95 to 130 threads / inch.

22. The glass cloth according to claim 1 or 7, wherein, The thickness of the glass cloth is in the range of 8μm to 18μm.

23. The glass cloth according to claim 22, wherein, The thickness of the glass cloth is in the range of 9μm to 17μm.

24. The glass cloth according to claim 22, wherein, The thickness of the glass cloth is in the range of 10μm to 15μm.

25. The glass cloth according to claim 1 or 7, wherein it has been surface-treated with a silane coupling agent.

26. The glass cloth according to claim 25, wherein, The silane coupling agent contains a silane coupling agent represented by the following general formula (1). X(R) 3-n Yes n (1) In general formula (1), X is an organic functional group having one or more amino groups, an organic functional group containing one or more unsaturated double bonds that are reactive with free radicals, or an organic functional group containing one or more amino groups and one or more unsaturated double bonds that are reactive with free radicals, Y is each independently an alkoxy group, n is an integer of 1 or more and 3 or less, and R is each independently a group selected from the group consisting of methyl, ethyl and phenyl.

27. The glass cloth according to claim 26, wherein, Y is an alkoxy group with 5 or fewer carbon atoms.

28. A prepreg, characterized in that, It contains glass cloth, thermosetting resin and inorganic filler as described in any one of claims 1 to 27.

29. A printed wiring board, characterized in that, It comprises the prepreg as described in claim 28.

30. An integrated circuit, characterized in that, It includes the printed wiring board as described in claim 29.

31. An electronic instrument, characterized in that, It includes the printed wiring board as described in claim 29.

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