JP2018127747A - Glass cloth, prepreg and printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: glass cloth low in dielectric constant which can manufacture prepregs and a printed wiring board excellent in insulation reliability or a substrate of a laminate or the like therefor (hereinafter simply described as "substrate"); and prepregs and a printed wiring board using the glass cloth.SOLUTION: The glass cloth is made by weaving a glass thread composed of a plurality of glass filaments. A composition amount of SiOin the glass filaments is 98-100 mass%, an average filament diameter of the glass filaments is 3-10 μm, the number of filaments of the glass filaments is 20-300, warp and weft constituting the glass cloth have each independently the placing density of 20-140/inch, the thickness of the glass cloth is 8-100 μm, an ignition loss value of the glass cloth is 0.12 mass% or more and 0.40 mass% or less, the dielectric constant of the glass cloth is 3.8 or lower and the surface of the glass thread is treated with a silane coupling agent containing an unsaturated double bond group.SELECTED DRAWING: None

Description

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

  Currently, along with the high performance and high speed communication of information terminals such as smartphones, the printed wiring boards used are becoming increasingly dense and extremely thin, and are also becoming increasingly low dielectric constant and low dielectric loss tangent. .

  As an insulating material of this printed wiring board, a laminated board obtained by laminating a prepreg obtained by impregnating a glass cloth with a thermosetting resin such as an epoxy resin (hereinafter referred to as “matrix resin”) and curing by heating and pressing. Is widely used. The dielectric constant of the matrix resin used for the high-speed communication substrate is about 3, whereas the dielectric constant of a general E glass cloth is about 6.7. It has become apparent. Note that the signal transmission loss is Edward A. As shown by the Wolff equation: transmission loss ∝√ε × tan δ, it is known that a material having a smaller dielectric constant (ε) and dielectric loss tangent (tan δ) is improved.

  Therefore, low dielectric constant glass cloths such as D glass, NE glass, and L glass having a glass composition different from that of E glass have been proposed (for example, see Patent Documents 1 to 4).

Japanese Patent Laid-Open No. 5-170483 JP2009-263569 JP2009-19150 JP 2009-263824 A

However, in future 5G communication applications and the like, these low dielectric constant glass cloths still have room for improvement from the viewpoint of achieving sufficient transmission speed performance. Here, it is conceivable to further lower the dielectric constant and lower the dielectric loss tangent by setting the amount of SiO ₂ in the glass composition to approximately 100%. However, when the amount of SiO _{2 in} the glass composition is increased to almost 100%, the hole workability with a mechanical drill generally used for a low dielectric constant substrate is significantly deteriorated. Therefore, at the time of drilling, the interface between the resin and the glass is easily peeled off, and thereafter, when the copper plating process is performed, the copper plating solution is likely to penetrate the interface. As a result, there is a problem that the insulation reliability between the holes of the laminate is deteriorated.

  The present invention has been made in view of the above problems, and has a low dielectric constant and excellent insulation reliability (“substrate” includes a prepreg, a printed wiring board, or a laminate of these, etc. It is an object of the present invention to provide a glass cloth capable of producing a concept, and a prepreg and a printed wiring board using the glass cloth.

As a result of investigations to solve the above problems, the present inventors have surface-treated a glass filament having a predetermined SiO ₂ composition amount with a silane coupling agent having a predetermined functional group, and the strength of the glass cloth. It has been found that the above problem can be solved by setting the heat loss value within a predetermined range, and the present invention has been completed.

That is, the present invention is as follows.
[1]
A glass cloth formed by weaving glass yarns composed of a plurality of glass filaments,
In the glass filament, the SiO ₂ composition amount is 98 to 100% by mass,
The average filament diameter of the glass filament is 3 to 10 μm,
The number of filaments of the glass filament is 20 to 300,
The driving density of the warp and weft constituting the glass cloth is each independently 20 to 140 pieces / inch,
The glass cloth has a thickness of 8 to 100 μm,
The ignition loss value of the glass cloth is 0.12% by mass or more and 0.40% by mass or less,
The dielectric constant of the glass cloth is 3.8 or less,
The surface of the glass yarn was treated with a silane coupling agent having an unsaturated double bond group,
Glass cloth.
[2]
The ignition loss value of the glass cloth is 0.2% by mass or more and 0.40% by mass or less.
The glass cloth according to [1].
[3]
The surface of the glass yarn was treated with two or more silane coupling agents having different molecular weights,
The glass cloth according to [1] or [2].
[4]
The SiO ₂ composition amount is 98 to 99.95% by mass.
The glass cloth according to any one of [1] to [3].
[5]
The glass cloth according to any one of [1] to [4];
A matrix resin impregnated in the glass cloth,
Prepreg.
[6]
Having the prepreg according to [5],
Printed wiring board.

  ADVANTAGE OF THE INVENTION According to this invention, the dielectric constant and the glass cloth which can produce the board | substrate excellent in insulation reliability, and the prepreg and printed wiring board using this glass cloth can be provided.

  Hereinafter, the embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. However, the present invention is not limited to this, and various modifications are possible without departing from the scope of the present invention. It is.

〔Glass cloth〕
The glass cloth of this embodiment is a glass cloth composed of glass yarns composed of a plurality of glass filaments, and the SiO ₂ composition amount is 98 to 100% by mass in the glass filament, and the average of the glass filaments The filament diameter is 3 to 10 μm, the number of filaments of the glass filament is 20 to 300, and the driving density of the warp and weft constituting the glass cloth is independently 20 to 140 / inch. The glass cloth has a thickness of 8 to 100 μm, the loss on ignition value of the glass cloth is 0.12% by mass or more and 0.40% by mass or less, and the dielectric constant of the glass cloth is 3 8 or less, and the surface of the glass yarn is treated with a silane coupling agent having an unsaturated double bond group.

When the SiO ₂ composition is 98 to 100% by mass, the dielectric constant is lowered, but the drillability of the substrate is remarkably deteriorated. A typical glass has a Vickers hardness of about 640 kgf / mm ² , but a glass having a SiO ₂ composition of almost 100% has a Vickers hardness of about 820 kgf / mm ² , and the tip of the drill tip is significantly worn during drilling. . Therefore, a drill hole having a rough shape with a rough inner wall of the hole is generated, and peeling (peeling portion) is likely to occur at the glass / resin interface on the inner wall of the hole. When a copper plating process or the like is performed, the plating solution easily penetrates into the glass cloth from the peeled portion, and the insulation reliability is lowered.

In addition, when the SiO ₂ composition amount is set to 98 to 100% by mass, the bending resistance of the glass filament is significantly lowered, and the glass filament is broken or broken. Broken or broken glass filaments become fluffed glass cloth. Since such fluffing occurs in the water washing and opening process after the surface treatment of the glass cloth, a glass cloth having no fluffing is easily produced using a glass filament having a SiO ₂ composition of 98 to 100% by mass. This is problematic from a practical point of view. In addition, in prepreg applications, glass filaments having such low bending resistance are inferior in practicality because they cause fuzz during processing. The fluffing increases the probability that the fluffing part collides with the conductive layer when producing a laminated plate, and causes a defective projection and an interlayer insulation failure. Therefore, conventionally, a glass cloth using a glass filament having a SiO ₂ composition amount of 98 to 100% by mass has a problem from the viewpoint of practicality.

  However, according to the glass cloth of this embodiment, the surface of the glass yarn is treated with a silane coupling agent having an unsaturated double bond group, and the ignition loss value of the glass cloth is 0.12% by mass or more. By making it 40% by mass or less, it becomes possible to improve the bending resistance of the glass filament while utilizing a low dielectric constant, and a substrate having a lower dielectric constant and superior insulation reliability than the conventional one. It is possible to provide a glass cloth that can be manufactured. In addition, the substrate using the glass cloth of the present embodiment has achieved further lower dielectric constant and lower dielectric loss tangent, and can achieve each performance required for high-speed communication. .

[Glass filament composition]
Glass filaments, SiO ₂ composition amount is 98 to 100 wt%, preferably from 98 to 99.95 mass%, more preferably 98-99 wt%. When the SiO ₂ composition is less than 98% by mass, the dielectric constant and dielectric loss tangent are increased. In addition, air easily enters during glass melt spinning, and hollow fibers are easily generated. As the number of hollow fibers increases, the insulation reliability of the substrate deteriorates. On the other hand, by setting the SiO ₂ composition amount to 98% by mass or more, it is possible to provide a glass cloth that can produce a substrate having a low dielectric constant and excellent insulation reliability. Further, since the SiO ₂ composition amount is 99.95% by mass or less, the bending resistance and brittleness resistance of the glass yarn is further improved, the drillability of the substrate is further improved, and after the glass cloth is processed. During fiber opening and washing with water, yarn breakage hardly occurs and the fluff amount of the glass cloth decreases. Therefore, by using such a glass cloth, the dielectric constant is further lowered, the insulation reliability derived from the hollow fiber reduction, the insulation reliability improved from the drilling workability of the substrate, and the fluffing Improvement in insulation reliability resulting from the reduction (prevention of plating soaking, defective protrusion, defective interlayer insulation, etc.) can be achieved. The SiO ₂ composition amount can be adjusted according to the amount of raw material used for glass filament preparation.

Further, the glass filament may have other composition besides SiO ₂ . Other compositions are not particularly limited, and examples include Al ₂ O ₃ , CaO, MgO, B ₂ O ₃ , TiO ₂ , Na ₂ O, K ₂ O, Sr ₂ O ₃ , Fe ₂ O _{3 and the} like. It is done.

[Average filament diameter of glass filament]
The average filament diameter of the glass filament is 3 μm to 10 μm, preferably 3.5 to 9 μm. When the average filament diameter of the glass filament is within the above range, workability tends to be further improved when the obtained substrate is processed by a mechanical drill. In particular, when the average filament diameter of the glass filament is 9 μm or less, the area of contact between the matrix resin and the glass filament per unit volume increases, so that the ignition loss value is 0.12% by mass or more, which will be described later. The effect tends to be expressed more greatly.

[Number of filaments of glass filament]
The number of filaments of the glass filament is 20 to 300, preferably 20 to 200. When the number of filaments of the glass filament is within the above range, workability tends to be further improved when the resulting substrate is processed with a mechanical drill.

[Pumping density]
The driving density of the warp and weft constituting the glass cloth is independently 20 to 140 yarns / inch, preferably 30 to 130 yarns / inch, and more preferably 40 to 120 yarns / inch.

〔thickness〕
The thickness of the glass cloth is 8 to 100 μm, preferably 15 to 90 μm, and more preferably 20 to 80 μm.

[Cloth weight (weight)]
The cloth weight (weight per unit area) of the glass cloth is preferably 6 to 100 g / m ² , more preferably 7 to 90 g / m ² .

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

〔surface treatment〕
The glass yarn (including the glass filament) of the glass cloth is surface-treated with a silane coupling agent having an unsaturated double bond group (hereinafter also simply referred to as “silane coupling agent”). By using a silane coupling agent having an unsaturated double bond group, the reactivity with the matrix resin is further improved, and a hydrophilic functional group is hardly generated after reacting with the matrix resin, and the insulation reliability is further improved. .

Although it does not specifically limit as a silane coupling agent which has an unsaturated double bond group, For example, the compound shown by following General formula (1) is mentioned. By using a silane coupling agent having an unsaturated double bond group, it is possible to reduce the plating solution penetration, insulation reliability, and fluffing quality after drilling a glass cloth having a SiO ₂ composition of 98 to 100% by mass. Can be improved.
X (R) _3-n SiY _n (1)
(In the formula, X is an organic functional group having one or more unsaturated double bond groups, Y is each independently an alkoxy group, n is an integer of 1 to 3, and R is And each independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group.)

  The organic functional group having one or more unsaturated double bond groups represented by X is not particularly limited, and examples thereof include a vinyl group, an allyl group, a vinylidene group, an acryloxy group, and a methacryloxy group.

  Any form can be used as the alkoxy group, but an alkoxy group having 5 or less carbon atoms is preferable for stabilizing the glass cloth.

  Specific examples of silane coupling agents that can be used include, but are not limited to, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane and its hydrochloride, N-β- (N -Vinylbenzylaminoethyl) -γ-aminopropylmethyldimethoxysilane and its hydrochloride, N-β- (N-di (vinylbenzyl) aminoethyl) -γ-aminopropyltrimethoxysilane and its hydrochloride, N-β -(N-di (vinylbenzyl) aminoethyl) -N-γ- (N-vinylbenzyl) -γ-aminopropyltrimethoxysilane and its hydrochloride, vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxy Known substances such as octyltrimethoxysilane and acryloxypropyltrimethoxysilane It is below. The silane coupling agent tends to be excellent in reactivity with a glass cloth glass fiber (glass filament) and a matrix resin of a substrate, particularly a radical polymerization resin. Therefore, it is possible to suppress a decrease in insulation reliability resulting from the resin and the glass cloth being easily peeled at the interface, and to suppress a decrease in insulation reliability resulting from the plating solution soaking into the glass cloth.

  The molecular weight of the silane coupling agent is preferably 100 to 600, more preferably 150 to 500, and still more preferably 200 to 450. Among these, it is preferable to use a silane coupling agent having two or more types of unsaturated double bond groups having different molecular weights. By treating the glass yarn surface with two or more types of silane coupling agents having different molecular weights, the treatment agent density on the glass surface is increased, and the reactivity with the matrix resin tends to be further improved. In addition, the processing amount by the surface treating agent of glass cloth can be estimated by the following ignition loss value.

[Ignition loss value]
The ignition loss value of the glass cloth is 0.12% by mass or more, preferably 0.15% by mass or more, and more preferably 0.2% by mass or more. Moreover, the upper limit of the ignition loss value of the glass cloth is 0.40% by mass or less, preferably 0.35% by mass or less, more preferably 0.30% by mass or less. When the loss weight loss value of the glass cloth is 0.12% by mass or more, the plating solution penetration, insulation reliability, and fluffing after drilling the glass cloth having a SiO ₂ composition of 98 to 100% by mass Quality can be improved. Further, the moisture absorption resistance is further improved, and the decrease in insulation reliability due to moisture absorption can be further suppressed. Moreover, when the ignition loss value of the glass cloth is 0.4% by mass or less, the resin permeability to the glass cloth is further improved, and as a result, the insulation reliability is further improved.

  The “ignition loss value” mentioned here can be measured according to the method described in JIS R3420. That is, first, the glass cloth is placed in a dryer at 110 ° C. and dried for 60 minutes. After drying, the glass cloth is transferred to a desiccator, left for 20 minutes, and allowed to cool to room temperature. After standing to cool, the glass cloth is weighed in units of 0.1 mg or less. Next, the glass cloth is heated in a muffle furnace at 625 ° C. for 20 minutes. After heating in the muffle furnace, the glass cloth is transferred to a desiccator, left for 20 minutes, and allowed to cool to room temperature. After standing to cool, the glass cloth is weighed in units of 0.1 mg or less. The amount of silane coupling agent treated with glass cloth is defined by the ignition loss value obtained by the above measurement method.

[Dielectric constant of glass cloth]
The dielectric constant of the glass cloth is 3.8 or less, preferably 3.7 or less. The dielectric constant of the glass cloth can be measured by the method described in the examples.

[Glass cloth manufacturing method]
The method for producing the glass cloth of the present embodiment is not particularly limited. For example, a coating step of almost completely covering the surface of the glass filament with a silane coupling agent with a treatment liquid having a concentration of 0.1 to 3.0 wt%, and heating A fixing step for fixing the silane coupling agent to the surface of the glass filament by drying, and at least part of the silane coupling agent fixed to the surface of the glass filament is washed with high-pressure spray water or the like, so that the ignition loss value is 0. And a preparation step of adjusting the adhesion amount of the silane coupling agent so as to be 12 to 0.40% by mass.

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

  The covering step, the fixing step, and the preparation step are preferably performed on the glass cloth after the weaving step. Furthermore, you may have the fiber opening process which opens the glass yarn of a glass cloth after a weaving process as needed. In addition, when performing a preparation process after a weaving process, an adjustment process may serve as a fiber opening process. In addition, the composition of the glass cloth does not usually change before and after opening.

  It is considered that the silane coupling agent layer can be formed almost completely and uniformly on the entire surface of each glass filament constituting the glass yarn by the above production method.

  As a method of applying the treatment liquid to the glass cloth, (a) a method of storing the treatment liquid in a bath and immersing and passing the glass cloth (hereinafter referred to as “immersion method”), (b) a roll coater, a die coater, Or the method of apply | coating a process liquid directly to glass cloth with a gravure coater etc. is possible. When applying by the immersion method (a), the immersion time of the glass cloth in the treatment liquid is preferably selected to be 0.5 seconds or more and 1 minute or less.

  In addition, examples of the method for heating and drying the solvent after applying the treatment liquid to the glass cloth include known methods such as hot air and electromagnetic waves.

  The heating and drying temperature is preferably 90 ° C. or higher, and more preferably 100 ° C. or higher so that the reaction between the silane coupling agent and glass is sufficiently performed. Moreover, in order to prevent deterioration of the organic functional group which a silane coupling agent has, 300 degrees C or less is preferable, and if it is 200 degrees C or less, it is more preferable.

In addition, the opening method in the opening step is not particularly limited, and examples thereof include a method of opening a glass cloth with spray water (high-pressure water opening), vibrowasher, ultrasonic water, mangle and the like. . In the fiber opening process, in the case of a glass cloth having a SiO ₂ composition amount of 98 to 100% by mass, fuzz is likely to occur. On the other hand, the ignition loss value of the glass cloth of the present embodiment is 0.12% by mass or more, whereby fuzz can be suppressed. Further, in order to suppress a decrease in the tensile strength of the glass cloth due to the fiber opening process, it is preferable to take measures such as reducing friction of the contact member when weaving the glass yarn, optimizing the sizing agent and increasing the amount of adhesion. . There is a tendency that the air permeability can be further reduced by lowering the tension applied to the glass cloth during the opening process.

  Even after the opening process, an optional process may be included. Although it does not specifically limit as an arbitrary process, For example, a slit process process is mentioned.

  After the glass cloth is surface-treated, a matrix resin is applied to manufacture a prepreg. The storage period between the surface treatment of the glass cloth and the application of the matrix resin is preferably within 2 years. Moreover, it is preferable that storage temperature shall be 10-40 degreeC. When the storage temperature is 30 ° C. or lower, the deactivation of unsaturated double bond groups of the silane coupling agent on the surface of the glass cloth can be suppressed, and the reactivity with the matrix resin tends to be maintained. Moreover, it exists in the tendency which can suppress that the silane coupling agent reacts with the water adhering to the glass surface, and the convergence property of a glass filament bundle increases because storage period is less than two years. This tends to improve the permeability of the matrix resin.

[Prepreg]
The prepreg of this embodiment has the glass cloth and a matrix resin impregnated in the glass cloth. Accordingly, it is possible to provide a prepreg that is thin, has a low dielectric constant, and has improved insulation reliability and improved moisture absorption resistance related to the above reasons.

  As the matrix resin, either a thermosetting resin or a thermoplastic resin can be used. The thermosetting resin is not particularly limited. For example, a) a compound having an epoxy group and an amino group, a phenol group, an acid anhydride group, a hydrazide group, an isocyanate group, a cyanate group, and a hydroxyl group that react with the epoxy group. An epoxy that is cured by reacting with a compound having at least one of the above, without a catalyst, or by adding a catalyst having a reaction catalytic ability such as an imidazole compound, a tertiary amine compound, a urea compound, or a phosphorus compound. A resin; b) a radical polymerization curable resin in which a compound having at least one of an allyl group, a methacryl group, and an acryl group is cured using a thermal decomposition catalyst or a photodecomposition catalyst as a reaction initiator; c D) a maleimide triazine resin cured by reacting a compound having a cyanate group with a compound having a maleimide group; Imide compounds, thermosetting polyimide resin is cured by reacting an amine compound, a; benzoxazine resin to crosslink cured by thermal polymerization of a compound having e) benzoxazine ring are exemplified.

  The thermoplastic resin is not particularly limited. For example, polyphenylene ether, modified polyphenylene ether, polyphenylene sulfide, polysulfone, polyether sulfone, polyarylate, aromatic polyamide, polyether ether ketone, thermoplastic polyimide, insoluble polyimide, Examples include polyamide imide and fluororesin. Moreover, you may use together a thermosetting resin and a thermoplastic resin.

[Printed wiring board]
The printed wiring board of this embodiment has the prepreg. Thereby, a printed wiring board having a low dielectric constant and improved insulation reliability can be provided.

  Next, the present invention will be described in more detail with reference to examples and comparative examples. The present invention is not limited in any way by the following examples.

Example 1
Glass cloth formed by weaving glass yarns of 98.5% by mass of SiO ₂ glass filaments (average filament diameter of glass filament 9 μm, number of filaments 100, warp driving density 54 / inch, weft driving density 54 Book / inch, thickness 78 μm, mass 69 g / m ² ), N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Toray Dow Corning Co., Ltd .; Z6032) It was immersed in a treatment liquid dispersed in water and dried by heating. Next, high-pressure water opening was carried out by spraying and heat drying to obtain a product. The loss on ignition value of the glass cloth was 0.13 wt%.

(Example 2)
Glass cloth formed by weaving glass yarns of 98.5% by mass of SiO ₂ glass filaments (average filament diameter of glass filament 9 μm, number of filaments 100, warp driving density 54 / inch, weft driving density 54 Book / inch, thickness 78 μm, mass 69 g / m ² ), N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Toray Dow Corning Co., Ltd .; Z6032) It was immersed in a treatment liquid dispersed in water and dried by heating. Next, high-pressure water opening was carried out by spraying and heat drying to obtain a product. The loss on ignition value of the glass cloth was 0.15 wt%.

(Example 3)
Glass cloth formed by weaving glass yarns of 98.5% by mass of SiO ₂ glass filaments (average filament diameter of glass filament 9 μm, number of filaments 100, warp driving density 54 / inch, weft driving density 54 Book / inch, thickness 78 μm, mass 69 g / m ² ), N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Toray Dow Corning Co., Ltd .; Z6032) It was immersed in a treatment liquid dispersed in water and dried by heating. Next, high-pressure water opening was carried out by spraying and heat drying to obtain a product. The loss on ignition value of the glass cloth was 0.21 wt%.

Example 4
Glass cloth made by weaving glass yarn composed of glass filaments of 99.5% by mass of SiO ₂ (average filament diameter of glass filament 9 μm, number of filaments 100, warp driving density 54 / inch, weft driving density 54 Book / inch, thickness 78 μm, mass 69 g / m ² ), N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Toray Dow Corning Co., Ltd .; Z6032) It was immersed in a treatment liquid dispersed in water and dried by heating. Next, high-pressure water opening was carried out by spraying and heat drying to obtain a product. The loss on ignition value of the glass cloth was 0.13 wt%.

(Example 5)
Glass cloth formed by weaving glass yarns of 98.5% by mass of SiO ₂ glass filaments (average filament diameter of glass filament 9 μm, number of filaments 100, warp driving density 54 / inch, weft driving density 54 Book / inch, thickness 78 μm, mass 69 g / m ² ) was dipped in a treatment solution in which methacryloxypropyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd .; Z6030) was dispersed in water and dried by heating. Next, high-pressure water opening was carried out by spraying and heat drying to obtain a product. The loss on ignition value of the glass cloth was 0.13 wt%.

(Example 6)
Glass cloth formed by weaving glass yarns of 98.5% by mass of SiO ₂ glass filaments (average filament diameter of glass filament 9 μm, number of filaments 100, warp driving density 54 / inch, weft driving density 54 this / inch, thickness of 78 .mu.m, the mass ^{69g / m 2), N-} β- (N- vinylbenzylaminoethyl)-.gamma.-aminopropyltrimethoxysilane hydrochloride (Dow Corning Toray Co., Ltd.; Z6032) and A methacryloxypropyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd .; Z6030) was immersed in a treatment solution dispersed in water and dried by heating. Next, high-pressure water opening was carried out by spraying and heat drying to obtain a product. The loss on ignition value of the glass cloth was 0.13 wt%.

(Comparative Example 1)
Glass cloth formed by weaving glass yarns of 98.5% by mass of SiO ₂ glass filaments (average filament diameter of glass filament 9 μm, number of filaments 100, warp driving density 54 / inch, weft driving density 54 Book / inch, thickness 78 μm, mass 69 g / m ² ), N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Toray Dow Corning Co., Ltd .; Z6032) It was immersed in a treatment liquid dispersed in water and dried by heating. Next, high-pressure water opening was carried out by spraying and heat drying to obtain a product. The loss on ignition value of the glass cloth was 0.11 wt%.

(Comparative Example 2)
Glass cloth formed by weaving glass yarns of 98.5% by mass of SiO ₂ glass filaments (average filament diameter of glass filament 9 μm, number of filaments 100, warp driving density 54 / inch, weft driving density 54 Book / inch, thickness 78 μm, mass 69 g / m ² ) was dipped in a treatment liquid in which N-phenyl-aminopropyltrimethoxyliran (manufactured by Shin-Etsu Silicone Co., Ltd .; KBM573) was dispersed in water and dried by heating. Next, high-pressure water opening was carried out by spraying and heat drying to obtain a product. The loss on ignition value of the glass cloth was 0.13 wt%.

(Comparative Example 3)
Glass cloth formed by weaving glass yarn composed of glass filaments of SiO ₂ of 95% by mass (average filament diameter of glass filament 9 μm, number of filaments 100, warp driving density 54 / inch, weft driving density 54 / inch, thickness 78 μm, mass 69 g / m ² ), N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride (manufactured by Toray Dow Corning Co., Ltd .; Z6032) in water It was immersed in the dispersed treatment liquid and dried by heating. Next, high-pressure water opening was carried out by spraying and heat drying to obtain a product. The loss on ignition value of the glass cloth was 0.13 wt%.

<Evaluation method of ignition loss value of glass cloth>
The ignition loss value was measured according to the method described in JIS R3420. Specifically, the glass cloth was placed in a dryer at 105 ° C. ± 5 ° C. and dried for at least 30 minutes. After drying, the glass cloth was transferred to a desiccator and allowed to cool to room temperature. After standing to cool, the weight of the glass cloth was measured in units of 0.1 mg or less. Next, the glass cloth was heated in a muffle furnace at about 625 ° C. for 20 minutes. After heating in the muffle furnace, the glass cloth was transferred to a desiccator and allowed to cool to room temperature. After standing to cool, the weight of the glass cloth was measured in units of 0.1 mg or less. The change in weight before and after heating of the muffle furnace was measured, and the ignition loss value was calculated as the amount of treatment agent attached.

<Evaluation of fluff of glass cloth (flexibility evaluation)>
Polyphenylene ether resin varnish (mixture of modified polyphenylene ether resin 30 parts by weight, triallyl isocyanurate 10 parts by weight, toluene 60 parts by weight, catalyst 0.1 part by weight) is added to the glass cloth obtained in the above-mentioned examples and comparative examples. A prepreg was obtained after impregnation and drying at 120 ° C. for 2 minutes. The resin content of this prepreg was adjusted to 50% by mass. Next, a small sample of 100 mm × 100 mm at an arbitrary location was cut out, and the number of protrusions was determined visually.

<Manufacturing method of substrate>
Polyphenylene ether resin varnish (mixture of modified polyphenylene ether resin 30 parts by weight, triallyl isocyanurate 10 parts by weight, toluene 60 parts by weight, catalyst 0.1 part by weight) is added to the glass cloth obtained in the above-mentioned examples and comparative examples. A prepreg was obtained after impregnation and drying at 120 ° C. for 2 minutes. This prepreg was stacked, a copper foil having a thickness of 12 μm was stacked on the top and bottom, and heated and pressed at 200 ° C. and 40 kg / cm ² for 60 minutes to obtain a substrate.

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

<Evaluation method of insulation reliability of substrate>
As described above, a substrate is prepared so as to have a thickness of 0.4 mm, and a wiring pattern in which through-holes with an interval of 0.15 mm are arranged on the copper foils on both sides of the substrate is prepared, and a sample for insulation reliability evaluation Got. A voltage of 10 V was applied to the obtained sample in an atmosphere of a temperature of 120 ° C. and a humidity of 85% RH, and a change in resistance value was measured. At this time, the case where the resistance was less than 1 MΩ within 500 hours after the start of the test was counted as an insulation failure. The same measurement was performed on 10 samples, and the ratio of the samples that did not show an insulation failure among the 10 samples was calculated.

  The evaluation results of the glass cloth shown in Examples and Comparative Examples are summarized in Table 1.

  It turned out that the glass cloth of an Example is very excellent in insulation reliability with a low dielectric constant.

  The glass cloth of the present invention has industrial applicability as a base material used for a printed wiring board used in the electronic / electric field.

Claims (6)

A glass cloth formed by weaving glass yarns composed of a plurality of glass filaments,
In the glass filament, the SiO ₂ composition amount is 98 to 100% by mass,
The average filament diameter of the glass filament is 3 to 10 μm,
The number of filaments of the glass filament is 20 to 300,
The driving density of the warp and weft constituting the glass cloth is each independently 20 to 140 pieces / inch,
The glass cloth has a thickness of 8 to 100 μm,
The ignition loss value of the glass cloth is 0.12% by mass or more and 0.40% by mass or less,
The dielectric constant of the glass cloth is 3.8 or less,
The surface of the glass yarn was treated with a silane coupling agent having an unsaturated double bond group,
Glass cloth. The ignition loss value of the glass cloth is 0.2% by mass or more and 0.40% by mass or less.
The glass cloth according to claim 1. The surface of the glass yarn was treated with two or more silane coupling agents having different molecular weights,
The glass cloth according to claim 1 or 2. The SiO ₂ composition amount is 98 to 99.95% by mass.
The glass cloth of any one of Claims 1-3. The glass cloth according to any one of claims 1 to 4,
A matrix resin impregnated in the glass cloth,
Prepreg. The prepreg according to claim 5 is provided.
Printed wiring board.