TW202146351A - Glass cloth, prepreg, and printed wiring board wherein the glass cloth is not easy to delaminate even under high temperature condition and has a high adhesion to a resin - Google Patents

Abstract

The present invention provides a glass cloth which is not easy to delaminate even under high temperature condition and has a high adhesion to a resin, and a prepreg and a printed wiring board using the glass cloth. The glass cloth of the invention is woven using a glass yarn composed of a plurality of glass filaments as a warp yarn and a weft yarn. The amount of extracts collected by acetone extraction treatment of the glass cloth is 50 ppm or less. The elastic modulus of the glass yarn is 50-70 GPa.

Description

Glass cloth, prepreg, and printed wiring board

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

With the development of the information communication society in recent years, data communication and/or signal processing can be performed at a large capacity and at a high speed, and the demand for lowering the dielectric constant of printed wiring boards used in electronic equipment is increasing. Therefore, among glass cloths constituting printed wiring boards, methods for efficiently producing low-dielectric glass cloths have been frequently proposed.

As described in Patent Document 1, in the production of glass cloth, in order to prevent fine hair or yarn breakage due to mechanical abrasion of the glass yarn in the warping step, weaving step, etc. The sizing agent coats the glass yarn, and after weaving, a heat treatment called thermal cleaning is performed to remove the sizing agent on the organic matter adhering to the glass yarn. In the manufacturing method of the low-dielectric glass cloth disclosed in Patent Document 1, specifically, for the conventionally used E glass cloth, the glass fiber fabric can be continuously passed through the glass fiber fabric while unwinding the roll. The heating furnace set so that the atmospheric temperature on the surface of the fiber fabric becomes 550-700°C, and heat treatment is performed, and the thermal cleaning step, which is a manufacturing step peculiar to glass fiber fabric, is efficiently performed. [Prior Art Literature] [Patent Literature]

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

[Problems to be Solved by Invention]

However, it is continuously passed through a heating furnace at a high temperature of 550 to 700°C as disclosed in Patent Document 1 using a batch-type thermal cleaning method at 350 to 500°C which is conventionally performed as described in Patent Document 1. In the case of the low-dielectric glass cloth that is thermally cleaned by the thermal cleaning method, when manufacturing printed wiring boards, it can be seen that under high temperature heating conditions or when an external load is applied, peeling occurs between the glass cloth and the resin.

The present invention has been developed in view of the above problems, and an object of the present invention is to provide a glass cloth that does not easily peel off even under high-temperature heating conditions and has high adhesion to resin, and a prepreg and printed wiring board using the glass cloth . [Technical means to solve problems]

The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, they found that the solution can be solved by adjusting the amount of acetone extract, which is an indicator of the amount of impurities attached to the glass surface, and the elastic modulus, which is an indicator of the strength of the glass filament. The present invention has been accomplished by solving the above-mentioned problems.

That is, the present invention is as follows. [1] A glass cloth comprising a glass yarn containing a plurality of glass filaments as a warp and a weft, wherein the amount of the extract captured by the extraction treatment with acetone of the glass cloth is 50 ppm or less, the glass yarn The modulus of elasticity is 50 to 70 GPa. [2] The glass cloth according to [1], wherein the elastic modulus of the glass yarn is 50 to 63 GPa. [3] The glass cloth according to [1] or [2], wherein the glass cloth has a thickness of 8 to 50 μm. [4] The glass cloth according to any one of [1] to [3], wherein the weight reduction rate A of the glass cloth in the heat treatment at 430° C. for 2 hours is 0.12 to 0.70 g/mm ² . [5] The glass cloth according to any one of [1] to [4], which has a dielectric constant of 5.0 or less at a frequency of 1 GHz. [7] A prepreg comprising: the glass cloth according to any one of [1] to [6], and a matrix resin impregnated in the glass cloth. [8] A printed wiring board comprising: the glass cloth according to any one of [1] to [6], a matrix resin impregnated with the glass cloth, and a metal foil. [Effect of invention]

According to the present invention, it is possible to provide a glass cloth that does not easily peel off even under high-temperature heating conditions and has high adhesion to resin, and a prepreg and printed wiring board using the low-dielectric glass cloth.

Hereinafter, an embodiment of the present invention (hereinafter, referred to as "the present embodiment") will be described in detail, but the present invention is not limited to this, and various changes can be made without departing from the gist.

The glass cloth of the present embodiment is constituted by using a glass yarn containing a plurality of glass filaments as a warp and a weft. Moreover, in the glass cloth of the present embodiment, the content of the extract captured by the extraction treatment with acetone is 50 ppm or less, and the elastic modulus of the glass yarn is 50 to 70 GPa.

In the case of manufacturing a printed wiring board using the low-dielectric glass cloth obtained by the previous thermal cleaning method, it can be seen that there is a part where the bonding strength of the interface between the glass cloth and the resin is weak. When exposed to high temperature conditions , or when a mechanical load is applied, there is a tendency to peel off easily at the interface between the glass cloth and the resin. The reason for this is not clear, but it is considered that one of the reasons is that the sizing agent is not removed and remains on the glass cloth, which should be removed by heating during thermal cleaning. The low dielectric glass tends to have a smaller elastic modulus than the previous E glass, and the rigidity of the printed wiring board is also smaller. Therefore, it can be seen that even if there is a sizing agent residue on the surface of the glass cloth equivalent to that of the previous E glass, in the low-dielectric glass, the bonding strength between the glass cloth and the resin at the sizing agent residue portion is weaker. The part becomes the starting point, and the peeling of the glass cloth and the resin occurs.

Therefore, from the viewpoint of avoiding the generation of such residues, it is preferable to perform thermal cleaning at a relatively high temperature. On the other hand, the low-dielectric glass cloth tends to volatilize the components constituting the glass at high temperature. Therefore, it is preferable to perform thermal cleaning at low temperature from the viewpoint of suppressing the decrease in the breaking strength of the glass yarn. On the other hand, in the present embodiment, it was found that a method can be provided by setting the elastic modulus to a specific range and setting the amount of residues on the glass cloth to be evaluated using the amount of acetone extract as an index within a specific range. Glass cloth that is not easy to peel off the resin from the glass cloth when printing the wiring board (not easy to delaminate under high temperature heating conditions). The details of the mechanism for producing such good adhesion have not yet been clarified, but it is considered that the residues remaining on the surface of the glass cloth are responsible for the difference in thermal expansion rate between the resin impregnated in the glass cloth and the glass cloth under high-temperature heating conditions, and between the two The interfacial stress caused by the relationship between the elastic modulus has an influence.

In this embodiment, the content of the extract captured by the extraction treatment with acetone of the glass cloth is used as an index of the adhesion between the glass cloth and the resin when the glass cloth is used as a printed wiring board. The content of the extract captured by the extraction treatment with acetone in the present embodiment is the content (ppm) of the component obtained by acetone extraction with the glass cloth, and specifically, it is measured by the method described in the examples.

The content of the extract captured by the extraction treatment with acetone is 50 ppm or less, preferably 40 ppm or less, and more preferably 30 ppm or less. Since the content of the extract is less than 50 ppm, it can prevent the glass cloth from peeling off the resin when the glass cloth is made into a printed wiring board, so that it can be used as a product normally. From the viewpoint of sufficiently removing the sizing agent and preventing the peeling of the glass cloth and the resin when the prepreg is made, the lower limit of the content of the extract is preferably 0 ppm, but may exceed 0 ppm. In addition, from the viewpoint of securing breaking strength, the lower limit of the content of the extract is preferably 10 ppm or more.

As a method of adjusting the content of the extract captured by the extraction treatment with acetone, for example, a method of controlling the heating temperature and/or the heating time in the thermal cleaning treatment can be mentioned. As a method of adjusting so that the content of the said extract may be lowered, specifically, control so as to increase the heating temperature, control so as to prolong the heating time, etc. are mentioned. In addition, it is also effective to wash the glass cloth before and/or after thermal cleaning to remove adhesions and/or burning residues adhering to the surface of the glass cloth, or to increase the preparation amount of the wax component of the sizing agent.

The elastic modulus of the glass yarn is 50-70 GPa, preferably 50-63 GPa, more preferably 53-63 GPa. The lower the elastic modulus of the glass yarn, the easier it is to break. Therefore, since the elastic modulus is 50 GPa or more, in the glass cloth manufacturing steps such as the fiber opening step or the surface treatment step, when the glass cloth is passed through a squeeze roller or a pinching reel in a wet state, it becomes It is not easy to produce the tendency to break. In addition, even in the later steps such as the production of the prepreg, when the glass cloth is passed through the slit for the purpose of controlling the impregnation amount of the resin into the glass cloth, there is a tendency that the breakage is less likely to occur. Moreover, since the elastic modulus of glass yarn is 70 GPa or less, there exists a tendency for a dielectric constant to fall relatively more. The elastic modulus can be measured by the method described in the examples. In addition, the elastic modulus can be adjusted by the composition of the glass yarn, or the melting temperature, spinning temperature, spinning speed, etc. at the time of producing the glass yarn.

The breaking strength of the glass cloth of the present embodiment is 50 N/25 mm or more, preferably 55 N/25 mm or more, and more preferably 65 N/25 mm or more. Since the breaking strength is 50 N/25 mm or more, it becomes difficult to break the glass yarn during the production process of the prepreg using the glass cloth. The upper limit of the above-mentioned breaking strength is not particularly limited, but is usually 300 N/25 mm or less. As a method of adjusting the breaking strength, for example, a method of controlling the heat treatment temperature and the treatment time in the desizing step described below can be mentioned. Specifically, the breaking strength was measured by the method described in the Examples.

The thickness of the glass cloth is preferably 8 to 50 μm, more preferably 10 to 50 μm, and still more preferably 11 to 50 μm. Since the thickness of the glass cloth is within the above range, there is a tendency to obtain a relatively thin and relatively high-strength glass cloth.

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

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

In the frequency of 1 GHz, the dielectric constant of the glass cloth of the present embodiment is preferably 5.0 or less, more preferably 4.8 or less, still more preferably 4.7 or less, and particularly preferably 4.5 or less. The dielectric constant of the glass cloth can be controlled by, for example, adjusting the composition of the glass constituting the glass cloth, or the method of the following weight reduction rate A, or the like. The dielectric constant can be measured, for example, by a cavity resonance method. Furthermore, in this embodiment, when referring to the dielectric constant, unless otherwise specified, it refers to the dielectric constant at a frequency of 1 GHz.

The weight reduction rate A (hereinafter, also simply referred to as "weight reduction rate A") when the glass cloth is heat-treated at 400°C for 2 hours is 0.12 to 0.70 g/mm ² , preferably 0.14 to 65 g/ mm ² , more preferably 0.15 to 60 g/mm ² . Since the weight reduction rate A is within the above-mentioned range, thermal cleaning can be reliably performed, and the strength reduction can be suppressed.

The weight reduction rate A can be adjusted by increasing/decreasing, for example, relatively volatile components in the composition of the glass yarn, such as B content, etc., and also by increasing/decreasing other components from the same viewpoint.

As an element which comprises a glass yarn, Si, B, Al, Ca, Mg, etc. are mentioned.

The Si content of the glass yarn is _{preferably 40 to 60 mass % in terms of SiO 2} , more preferably 45 to 55 mass %, further preferably 47 to 53 mass %, and still more preferably 48 to 52 mass %. Si is a component that forms the skeleton structure of the glass yarn, and since the Si content is 40% by mass or more, there is a tendency that the strength of the glass yarn is further improved, and the production process of the glass cloth and the use of the glass cloth tend to be as follows. In later steps such as the manufacture of the prepreg, the breakage of the glass cloth is further suppressed. Moreover, since Si content is 40 mass % or more, there exists a tendency for the dielectric constant of a glass cloth to fall more. On the other hand, since Si content is 60 mass % or less, it exists in the manufacturing process of glass filaments, and the glass fiber of the glass composition with the viscosity at the time of melting is further lowered and a more homogeneous glass tends to be obtained. Therefore, in the obtained glass filaments, it becomes difficult to generate parts that are prone to local devitrification, or parts that are difficult to leak local air bubbles. Therefore, it becomes difficult to locally generate weak parts in the glass filaments. As a result, the use of The glass cloth of the glass yarn obtained from the glass filaments becomes less prone to breakage. The Si content can be adjusted according to the amount of raw materials used in the production of glass filaments.

The B content of the glass yarn is preferably 15 to 30 mass %, more preferably 17 to 28 mass %, more preferably 20 to 27 mass %, and still more preferably 21 to 25 mass % _{in terms of B 2} O ₃ %, more preferably 21.5 to 24 mass %. Since the B content is 15 mass % or more, the dielectric constant tends to decrease more. Moreover, since the B content is 30 mass % or less, there exists a tendency for the moisture absorption resistance to improve and insulation reliability to improve more. The content of B can be adjusted according to the amount of raw materials used in the production of glass filaments. Furthermore, when there may be changes in the production process of the glass filaments, the changes can be predicted in advance and the feeding amount can be adjusted.

The Ca content of the glass yarn is preferably 5 to 10% by mass, more preferably 5 to 9% by mass, and more preferably 5 to 8.5% by mass in terms of CaO. Since the Ca content is 4 mass % or more, it exists in the manufacturing process of glass filaments, and there exists a tendency for the glass fiber of the glass composition with the lower viscosity at the time of melting and a more homogeneous glass to be obtained. Moreover, since the Ca content is 10 mass % or less, there exists a tendency for a dielectric constant to improve more. The Ca content can be adjusted according to the amount of raw materials used in the production of glass filaments.

The Mg content of the glass yarn is preferably 5 mass % or less, more preferably 3 mass % or less, still more preferably 0.01 to 1 mass % or less, still more preferably 0.05 to 0.6 mass % or less, in terms of MgO conversion. More preferably, it is 0.05-0.3 mass % or less. Since the Mg content is 5 mass % or less, it is present in the fiber opening step or surface treatment step during glass cloth production, and when the glass cloth is passed through a squeeze roller or a nip roll in a wet state, it becomes difficult to break. tendency. In addition, phase separation during the production of glass filaments is suppressed, and the moisture absorption resistance of the obtained glass filaments is further improved. Thereby, the obtained printed wiring board is not easily affected by the use environment of the high-humidity environment, and the environmental dependence of the dielectric constant can be reduced. The Mg content can be adjusted according to the amount of raw materials used in the production of glass filaments.

In addition, each content mentioned above can be measured by ICP (Inductively Coupled Plasma, inductively coupled plasma) emission spectrometry. Specifically, the Si content and the B content can be obtained by dissolving the weighed glass cloth sample in sodium carbonate, dissolving it in dilute nitric acid, and measuring the obtained sample by ICP emission spectrometry. In addition, the Fe content can be obtained by dissolving the weighed glass cloth sample by the alkali dissolution method to constant volume, and measuring the obtained sample by the ICP emission spectrometry method. Furthermore, the Al content, the Ca content, and the Mg content can be obtained by heating and decomposing the weighed glass cloth sample with sulfuric acid, nitric acid and hydrogen fluoride, dissolving it in dilute nitric acid to make a constant volume, and measuring the obtained sample by ICP emission spectrometry. get. In addition, as an ICP emission spectroscopic analyzer, PS3520VDD II manufactured by Hitachi High-Tech Science Co., Ltd. can be used.

The glass yarn is obtained by gathering a plurality of glass filament bundles and twisting as necessary, and the glass cloth is obtained by weaving the above-mentioned glass yarn as a warp and a weft. Glass yarns are classified as multifilaments and glass filaments are classified as monofilaments. The average diameters of the glass filaments constituting the warp and the weft are each independently preferably 2.5 to 9 μm, more preferably 3.0 to 7.5 μm, still more preferably 3.5 to 5.4 μm. Since the average diameter of the glass filaments is within the above-mentioned range, there is a tendency that the workability is further improved when the substrate obtained is processed by a mechanical drill, a carbon dioxide gas laser, or a UV-YAG laser. Therefore, a thin and high-density printed wiring board can be realized. In particular, when the average diameter is 5.4 μm or less, the surface area per unit volume increases and residues tend to adhere. Therefore, the effect of improving the bonding strength to resin in the glass cloth of the present embodiment becomes more important. In addition, since the average diameter is 2.5 μm or more, there is a tendency that, in the glass cloth manufacturing steps such as the fiber opening step or the surface treatment step, when the glass cloth is passed through a squeeze roller or pinched in a wet state In the case of a reel or the like, it becomes difficult to break. In addition, even in the later steps such as the production of the prepreg, when the glass cloth is passed through the slit for the purpose of controlling the impregnation amount of the resin into the glass cloth, it tends to be less prone to breakage.

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

The glass cloth may also be surface-treated with a surface-treating agent. Although it does not specifically limit as a surface treatment agent, For example, a silane coupling agent can be mentioned, and water, an organic solvent, an acid, a dye, a pigment, a surfactant, etc. may be used together as needed.

Although it does not specifically limit as a silane coupling agent, For example, the compound represented by Formula (1) is mentioned. X(R) _3-n SiY _n ･･･(1) (In formula (1), X is an organic functional group having at least one or more of an amine group and an unsaturated double bond group, and Y is each independently an alkane In the oxy 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 a methyl group, an ethyl group, and a phenyl group).

X is preferably an organic functional group having at least 3 or more among amine groups and unsaturated double bond groups, and X is more preferably an organic functional group having at least 4 or more among amine groups and unsaturated double bond groups.

Although any form can be used as the above-mentioned alkoxy group, from the viewpoint of stabilizing the glass cloth, an alkoxy group having 5 or less carbon atoms is preferable.

Specific examples of the silane coupling agent include N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-( N-vinylbenzylaminoethyl)-γ-aminopropylmethyldimethoxysilane and its hydrochloride, N-β-(N-bis(vinylbenzyl)aminoethyl) -γ-Aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-bis(vinylbenzyl)aminoethyl)-N-γ-(N-vinylbenzyl)- γ-Aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-benzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β -(N-benzylaminoethyl)-γ-aminopropyltriethoxysilane and its hydrochloride, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ- (2-aminoethyl)aminopropyltriethoxysilane, aminopropyltrimethoxysilane, vinyltrimethoxysilane, methacryloyloxypropyltrimethoxysilane, acryloxy Well-known monomers such as propylpropyltrimethoxysilane, or mixtures thereof.

The molecular weight of the silane coupling agent is preferably 100-600, more preferably 150-500, and still more preferably 200-450. Among them, it is preferable to use two or more kinds of silane coupling agents having different molecular weights. By using two or more types of silane coupling agents with different molecular weights to treat the surface of the glass yarn, the density of the surface treatment agent on the surface of the glass cloth tends to increase, and the reactivity with the matrix resin tends to increase.

[Manufacturing method of glass cloth] The manufacturing method of the glass cloth of the present embodiment is not particularly limited, and examples include a weaving step of weaving a glass yarn to obtain a glass cloth, a fiber opening step of subjecting the glass yarn of the glass cloth to fiber opening, and A method for the desizing step of removing the sizing agent from the glass yarn of the cloth. In addition, if necessary, there may be a surface treatment step by a silane coupling agent or the like.

The weaving method is to weave the weft and warp yarns so as to form a specific weave structure, and there is no particular limitation. Moreover, although it does not specifically limit as a fiber opening method, For example, the method of performing a fiber opening process by spraying water (high pressure water fiber opening), a vibration washing machine, ultrasonic water, a winder dryer, etc. is mentioned.

Furthermore, although it does not specifically limit as a desizing method, For example, the method of removing a sizing agent by heating is mentioned. In addition, in the weaving step and the like, a sizing agent is used for the purpose of protection against breakage of the glass yarn. Although it does not specifically limit as such a sizing agent, For example, a starch-type adhesive agent and a polyvinyl alcohol-type adhesive agent are mentioned. The starch-based adhesive and the polyvinyl alcohol-based adhesive contain at least starch and polyvinyl alcohol, respectively, and may be a mixture with waxes.

The temperature at which the sizing agent is removed by heating (thermal cleaning) is preferably 300 to 550° C., more preferably 350 to 480° C., and still more preferably 370° C., from the viewpoint of sufficiently removing the sizing agent while maintaining the breaking strength. ~450°C. The heating time may be appropriately adjusted according to conditions such as the heating temperature and the thickness of the glass cloth, and from the viewpoint of sufficiently removing the sizing agent while maintaining the breaking strength, it is preferably 20 to 80 hours, more preferably 25 to 70 hours , and more preferably 30 to 60 hours. In the desizing step of removing the sizing agent attached to the glass yarn from the glass cloth, before and/or after the sizing agent is heated and removed, the sizing agent before heating and/or the sizing agent after heating can also be removed by washing with water. Burning residue adhering to the surface of the glass cloth.

Moreover, as a surface treatment method, the method of making the surface treatment agent containing a silane coupling agent contact a glass cloth, and drying, etc. are mentioned. In addition, the contact between the surface treatment agent and the glass cloth includes a method of dipping the glass cloth in the surface treatment agent; or coating the glass cloth with a roll coater, a die coater, or a gravure coater, etc. Method of surface treatment agent, etc. Although it does not specifically limit as a drying method of a surface treatment agent, For example, the drying method using hot air drying or an electromagnetic wave is mentioned.

[prepreg] The prepreg of this embodiment has the above-mentioned low-dielectric glass cloth and a matrix resin composition impregnated in the low-dielectric glass cloth. The above-mentioned prepreg with glass cloth has higher adhesiveness to resin and higher yield of final product. In addition, since it has excellent dielectric properties and excellent moisture absorption resistance, it is also possible to provide an effect such as being able to provide a printed wiring board with little variation in dielectric constant under the influence of the use environment, especially in a high-humidity environment.

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

As the matrix resin composition, in addition to the above epoxy resins, bismaleimide resins, isocyanate resins, unsaturated polyester resins, polyimide resins, BT (Bismaleimide Triazine, bismaleimide Thermosetting resins such as triazine) resins and functionalized polyphenylene ether resins; thermoplastic resins such as polyphenylene ether resins, polyetherimide resins, liquid crystal polymers (LCP) of wholly aromatic polyesters, polybutadiene, and fluororesins Resins; mixed resins thereof, etc. From the viewpoint of improving dielectric properties, heat resistance, solvent resistance, and press moldability, a resin obtained by modifying a thermoplastic resin with a thermosetting resin may also be used as the matrix resin composition.

In addition, the matrix resin composition can 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; thermal stabilizers; antistatic Agents; UV Absorbers; Pigments; Colorants; Lubricants, etc.

[Printed Wiring Board] The printed wiring board of the present embodiment includes the above-mentioned prepreg. The printed wiring board provided with the prepreg of the present embodiment has high adhesiveness to resin and high yield of the final product. In addition, since it is excellent in dielectric properties and excellent in moisture absorption resistance, it is also possible to exert the effect that the variation of the dielectric constant is small under the influence of the use environment, especially in the high humidity environment. [Example]

Hereinafter, the present invention will be described in more detail using Examples and Comparative Examples. The present invention is not limited in any way by the following examples.

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

[Amount of extract captured by extraction with acetone] In the present embodiment, the content of the extract captured by the extraction treatment with acetone was measured in the following procedure. 1) Put glass cloth (A4 size × 3 pieces) and 300 mL of acetone in a beaker, and stir with a stirring bar for 5 minutes. 2) Next, suction filtration was performed using a membrane filter made of polytetrafluoroethylene (PTFE) with a mesh size of 1 μm. 3) 250 mL of acetone was added to the remaining glass cloth, and after stirring with a stirring bar for 5 minutes, suction filtration was performed in the same manner as in 2) above. 4) Repeat the above 3) operation once. 5) Air dry the membrane filter. 6) The acetone extract captured on the membrane filter was weighed, and the value obtained by dividing the acetone extract by the mass of the glass cloth was taken as the amount (ppm) of the acetone extract. In addition, when the glass yarn detached from the glass cloth was caught on the membrane filter, the glass yarn was removed and weighed (the membrane filter was tare in advance).

[Modulus of elasticity] The elastic modulus was measured by the pulse echo superposition method.

[Breaking strength of glass cloth in warp direction] The breaking strength of the glass cloth in the warp direction shall be measured by applying the method described in the general test method for glass test of JIS R3420 and 7.4 Tensile strength. The tensile test was carried out under the conditions that the width of the test piece was 25 mm and the tensile speed was 200 mm/1 min after the yarns at both ends of the test piece were unwound at an interval of 150 mm, and the load at break was read. . The test was performed 5 times, and the breaking strength was calculated|required from the average value.

[Weight reduction rate A] The measurement method of the weight reduction rate A was performed according to the following procedure. First, the weight of the glass cloth stored in the desiccator was measured in a dry state. Next, after heat-processing the glass cloth at 430° C. for 2 hours, the glass cloth was moved to a desiccator again and left to cool. Measuring the weight of the glass has been placed the cloth is cooled, determine the weight reduction of ² per 1 mm, the weight reduction rate was calculated. In addition, in the case where the glass cloth after surface treatment is used as an object, it measures after performing the operation of removing a surface treatment agent as needed.

[The composition of glass yarn] The composition constituting the glass yarn was measured by ICP emission spectrometry. Specifically, the Si content and the B content are obtained by dissolving the weighed glass cloth sample in sodium carbonate, dissolving it in dilute nitric acid, and then measuring the obtained sample by ICP emission spectrometry. In addition, the Fe content is obtained by dissolving the weighed glass cloth sample by the alkali dissolution method, and measuring the obtained sample by the ICP emission spectrometry method. Furthermore, the Al content, the Ca content, and the Mg content are obtained by heating and decomposing the weighed glass cloth sample with sulfuric acid, nitric acid and hydrogen fluoride, dissolving it in dilute nitric acid to make a constant volume, and measuring the obtained sample by ICP emission spectrometry. . In addition, as an ICP emission spectroscopic analyzer, PS3520VDD II manufactured by Hitachi High-Tech Science Co., Ltd. was used.

[Strength Confirmation Test] Using the glass cloths obtained in Examples and Comparative Examples, prepregs were produced under the following conditions. While the glass cloth is continuously drawn out and conveyed, the glass cloth is dipped in the varnish and passed through the slit to adjust the coating amount of the varnish. Then, it was made to dry by the drying furnace of 160 degreeC, and the prepreg was obtained. In addition, at this time, the resin content in Examples 1 to 6 and Comparative Example 1 was changed to 71%, the resin content in Examples 7, 8, and Comparative Example 2 was changed to 66%, and Examples 9, 10, and Comparative Example 3. Adjust the resin content so that it becomes 58%. In addition, the varnish contains 65 parts by mass of methacrylated polyphenylene ether, 35 parts by mass of triallyl isocyanurate, 10 parts by mass of hydrogenated styrene thermoplastic elastomer, 25 parts by mass of brominated flame retardant, spherical 65 parts by mass of silicon oxide, 1 part by mass of organic peroxide, and 210 parts by mass of toluene. [Interlayer peel strength] 1) Preparation of laminate test pieces related to peel strength Four prepregs obtained in the strength confirmation test were stacked, and copper foil (manufactured by Furukawa Electric Co., Ltd., thickness 18 μm, GTS- MP foil) was superimposed on both surfaces of the prepreg which was superimposed, and ^{vacuum pressure was performed at 200° C. at 30 kg/cm 2} for 60 minutes to obtain a copper foil laminate. Then, a laminated board was obtained by removing copper foil from the said copper foil laminated board by etching. 2) Measurement of peeling strength of copper foil The laminate was cut into a glass cloth of 10 mm in the weft direction (width) x 150 mm in the warp direction (length). Peel off 50 mm in the longitudinal direction between the glass cloth of the outermost layer on one side of the laminate and the glass cloth of the second layer. Using an autostereograph (manufactured by Shimadzu Corporation), the strength when the peeled outermost layer was peeled off by 50 mm in the 90-degree direction at a speed of 50 mm/min was measured. Furthermore, since the output intensity shows a wave shape with high and low peaks, it is set as the average value of the peaks of 5 points from the lowest point and 5 points from the highest point. The test was carried out five times, and the relative peel strength was obtained from the average value.

[T288 heat resistance test] 1) Preparation of laminate test piece for T288 heat resistance test: 8 pieces of the prepreg obtained in the strength confirmation test were superimposed, and then copper foil (manufactured by Furukawa Electric Co., Ltd., thickness 35 μm) was laminated. , GTS-MP foil) was superimposed on both sides of the superimposed prepreg at 200° C. at 30 kg/cm ² for 60 minutes under vacuum to obtain a copper foil laminate. 2) T288 heat resistance test Using a thermomechanical analyzer (TMA: thermomechanical analyzer), the time until the test piece was delaminated under the condition of 288°C was measured. The test pieces were cut into 6.35 mm squares, dried in an oven at 105°C for 2 hours, and then cooled to room temperature at 23°C in a desiccator. A load of 0.005 N was applied to the test piece, and under the load, it was heated from room temperature to 288°C at a temperature increase rate of 10°C/min. After reaching 288°C, the temperature was maintained at 288°C until delamination occurred. The time after reaching 288°C until delamination occurred was recorded as the result of the T288 test. In addition, the test piece which did not delaminate after 60 minutes after reaching 288 degreeC was stopped in 60 minutes, and it was recorded as 60 minutes or more (>60).

[Example 1] Glass composition (SiO ₂ : 51 mass %, Al ₂ O ₃ : 14 mass %, MgO: 0.1 mass %, CaO: 9 mass %, B ₂ O ₃ : 23 mass %), elastic modulus Glass yarn of 61 GPa, average filament diameter of 4.0 μm, and 50 filaments was woven with an air-jet weft loom with a weaving density of 95.0 pieces/25 mm of glass cloth. The thickness of the glass cloth is 13 μm. Next, it heat-processed at 400 degreeC for 42 hours, and performed desizing process, and obtained the glass cloth intermediate body. Next, the coating of the silane coupling agent and the fiber opening treatment were performed, and the glass cloth with the characteristics shown in Table 1 was obtained.

[Example 2] A glass cloth was obtained in the same manner as in Example 1, except that the heating conditions of the desizing treatment were set to 400° C.×36 hours.

[Example 3] A glass cloth was obtained in the same manner as in Example 1, except that the heating conditions of the desizing treatment were set to 400° C.×30 hours.

[Example 4] The glass composition was SiO ₂ : 50 mass %, Al ₂ O ₃ : 17 mass %, MgO: 0.1 mass %, CaO: 4 mass %, B ₂ O ₃ : 23 mass %, P ₂ O _A glass cloth was obtained by the same method as in Example 2, except that it was 5:4 mass % and the elastic modulus was set to 56 GPa.

[Comparative Example 1] A glass cloth was obtained by the same method as in Example 1, except that the heating conditions of the desizing treatment were set to 400° C.×24 hours. Due to the large amount of acetone extract, the interlayer peel strength is low, and the heat resistance of T288 is also deteriorated.

[Example 5] The glass cloth before desizing treatment was D glass (SiO ₂ : 72 mass %, Al ₂ O ₃ : 1 mass %, MgO: 0.1 mass %, CaO: 1 mass %, B ₂ O ₃ : 23 mass %), except that the elastic modulus was set to 52 GPa, a glass cloth was obtained by the same method as in Example 2. When the elastic modulus becomes smaller, the interlayer peel strength and T288 heat resistance also tend to decrease.

[Example 6] After the weaving of the glass cloth, before the desizing treatment by heating, the pre-desizing treatment of the glass cloth by washing with water is performed, and the conditions of the desizing treatment by heating are set to 400°C × 30 hours. Glass cloth was obtained in the same manner as in Example 1.

[Example 7] Glass composition (SiO ₂ : 51 mass %, Al ₂ O ₃ : 14 mass %, MgO: 0.1 mass %, CaO: 9 mass %, B ₂ O ₃ : 23 mass %), elastic modulus Glass cloth with 61 GPa, average filament diameter of 5.0 μm, and 100 filaments. Using an air-jet weft loom, the weaving density of woven warp yarns is 65.0 yarns/25 mm, and the weaving density of weft yarns is 67.0 yarns/25 mm. The thickness of the glass cloth is 28 μm. Then, it heat-processed at 400 degreeC for 42 hours, and performed desizing process, and obtained the glass cloth intermediate body. Next, the coating of the silane coupling agent and the fiber opening treatment were performed, and the glass cloth with the characteristics shown in Table 1 was obtained.

[Example 8] A glass cloth was obtained in the same manner as in Example 7, except that the heating conditions of the desizing treatment were set to 400° C.×36 hours.

[Comparative Example 2] A glass cloth was obtained in the same manner as in Example 7, except that the heating conditions of the desizing treatment were set to 400° C.×24 hours. Due to the large amount of acetone extract, the interlayer peel strength is low, and the heat resistance of T288 is also deteriorated.

[Example 9] Glass composition (SiO ₂ : 51 mass %, Al ₂ O ₃ : 14 mass %, MgO: 0.1 mass %, CaO: 9 mass %, B ₂ O ₃ : 23 mass %), elastic modulus Glass yarn with 61 GPa, average filament diameter of 5.0 μm, and 200 filaments was woven with an air-jet weft loom with a weaving density of 52.5 pieces/25 mm of glass cloth. The thickness of the glass cloth is 45 μm. Then, it heat-processed at 400 degreeC for 42 hours, and performed desizing process, and obtained the glass cloth intermediate body. Next, the coating of the silane coupling agent and the fiber opening treatment were performed, and the glass cloth with the characteristics shown in Table 1 was obtained.

[Example 10] A glass cloth was obtained in the same manner as in Example 9, except that the heating conditions of the desizing treatment were set to 400° C.×36 hours.

[Comparative Example 3] A glass cloth was obtained in the same manner as in Example 9, except that the heating conditions of the desizing treatment were set to 400° C.×24 hours. Due to the large amount of acetone extract, the interlayer peel strength is low, and the heat resistance of T288 is also deteriorated.

Table 1 shows the results of Examples and Comparative Examples.

[Table 1] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Example 5 Example 6 Example 7 Example 8 Comparative Example 2 Example 9 Example 10 Comparative Example 3 glass cloth Thickness (μm) 13 13 13 13 13 13 13 28 28 28 45 45 45 Amount of acetone extract (ppm) 14 31 45 30 61 31 13 12 35 59 15 38 63 elastic modulus 61 61 61 56 61 52 61 61 61 61 61 61 61 Breaking strength 59 64 75 54 75 65 64 60 64 68 67 78 78 Weight loss rate due to heat treatment at 430°C 0.28 0.28 0.27 0.53 0.27 0.27 0.27 0.024 0.024 0.023 0.023 0.023 0.025 Evaluation Coating test no problem no problem no problem no problem no problem no problem no problem no problem no problem no problem no problem no problem no problem interlayer peel strength 0.7 0.7 0.6 0.6 0.2 0.3 0.6 0.8 0.8 0.3 0.9 0.9 0.3 T288 (minutes) >60 >60 >60 >60 4 18 >60 >60 >60 5 >60 >60 14 [Industrial Availability]

The present invention has industrial applicability as a low-dielectric glass cloth used for prepregs and the like.

Claims (7)

A glass cloth composed of glass yarns containing a plurality of glass filaments as warp yarns and weft yarns, The amount of extracts captured by the above-mentioned glass cloth extraction treatment with acetone is less than 50 ppm, and The elastic modulus of the glass yarn is 50-70 GPa. Such as the glass cloth of claim 1, wherein The elastic modulus of the glass yarn is 50-63 GPa. The glass cloth of claim 1 or 2, wherein The thickness of the glass cloth is 8-50 μm. The glass cloth according to any one of claims 1 to 3, wherein the weight reduction rate A of the glass cloth in the heat treatment at 430° C. for 2 hours is 0.12 to 0.70 g/mm ² . The glass cloth of any one of claims 1 to 4, wherein At a frequency of 1 GHz, it has a dielectric constant below 5.0. A prepreg having: If the glass cloth of any one of Claims 1 to 5, and The matrix resin impregnated in the glass cloth. A printed wiring board having: If the glass cloth of any one of claims 1 to 5, the matrix resin impregnated in the glass cloth, and metal foil.