JP6915999B2 - Glass cloth, prepreg, and printed wiring board - Google Patents

Description

The present invention relates to glass cloths, prepregs, and printed wiring boards.

At present, along with the high performance and high-speed communication of information terminals such as smartphones, the printed wiring boards used are becoming denser and ultrathin, and the dielectric constant and the dielectric loss tangent are remarkably progressing. ..

As an insulating material for this printed wiring board, a laminated board obtained by impregnating a glass cloth with a thermosetting resin such as an epoxy resin (hereinafter referred to as "matrix resin") and laminating a prepreg is laminated and cured by heating and pressure. Is widely used. While the dielectric constant of the matrix resin used for the above-mentioned high-speed communication board is about 3, the dielectric constant of a general E glass cloth is about 6.7, which causes a problem of high dielectric constant at the time of a laminated plate. It is becoming apparent. The signal transmission loss is described in Edward A. et al. Wolff equation: As shown by the transmission loss ∝√ε × tanδ, it is known that the material having a smaller dielectric constant (ε) and dielectric loss tangent (tanδ) 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 (see, for example, Patent Documents 1 to 4).

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

However, in future 5G communication applications and the like, there is still room for improvement in these low dielectric constant glass cloths from the viewpoint of achieving sufficient transmission speed performance. Here, it is conceivable to further reduce the dielectric constant and the low dielectric loss tangent by setting the amount _{of SiO 2} in the glass composition to be approximately 100%. However, if _{the blending amount of SiO 2 in} the glass composition is increased to almost 100%, the hole workability of a mechanical drill generally used for a low dielectric constant substrate is significantly deteriorated. Therefore, the interface between the resin and the glass is likely to be peeled off during hole processing, and then the copper plating solution is likely to permeate the interface. As a result, there is a problem that the insulation reliability between the holes of the laminated board is deteriorated.

The present invention has been made in view of the above problems, and includes a substrate having a low dielectric constant and excellent insulation reliability (the "board" includes a prepreg, a printed wiring board, a laminated plate thereof, and the like. It is an object of the present invention to provide a glass cloth capable of producing (which is a concept), a prepreg using the glass cloth, and a printed wiring board.

As a result of studies for solving the above-mentioned problems, the present inventors have found that a predetermined glass cloth can solve the above-mentioned problems, and have completed the present invention.

That is, the present invention is as follows.
[1]
A glass cloth made by weaving glass threads composed of a plurality of glass filaments as warp threads and weft threads.
One of said warp and said weft, a glass yarn SiO ₂ composition amount is made of glass filaments is 98 to 100 wt%,
The other of the warp and the weft, a SiO ₂ composition weight 45 to 60 wt%, a glass yarn B ₂ O ₃ composition amount is made of glass filaments is 15 to 30 wt%,
The average filament diameters of the warp threads and the glass filaments constituting the weft threads are independently 3 to 10 μm.
The number of filaments of the warp and the weft is 20 to 300 independently.
The driving densities of the warp and the weft are independently 20 to 140 threads / inch.
The thickness of the glass cloth is 8 to 100 μm.
The ignition loss value of the glass cloth is 0.2% by mass or more and 1.0% by mass or less.
The dielectric constant of the glass cloth is more than 3.8 and 4.4 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 0.3% by mass or more and 0.8% by mass or less.
The glass cloth according to [1].
[3]
The surface of the glass yarn was treated with two or more kinds of the silane coupling agents having different molecular weights.
The glass cloth according to [1] or [2].
[4]
One of said warp and said weft, the SiO ₂ composition weight of glass strands consisting of glass filaments is 98 to 99.95 wt%,
The glass cloth according to any one of [1] to [3].
[5]
The other of the warp and the weft, the a SiO ₂ composition weight 50-60 wt%, the B ₂ O ₃ composition weight of glass strands consisting of glass filaments is 20 to 30 wt%,
The glass cloth according to any one of [1] to [4].
[6]
The glass cloth according to any one of [1] to [5] and
The glass cloth is impregnated with a matrix resin.
Prepreg.
[7]
Having the prepreg according to [6].
Printed wiring board.

According to the present invention, it is possible to provide a glass cloth capable of producing a substrate having a low dielectric constant and excellent insulation reliability, a prepreg using the glass cloth, and a printed wiring board.

Hereinafter, embodiments of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail, but the present invention is not limited thereto, and various modifications can be made without departing from the gist thereof. Is.

〔Glass cloth〕
The glass cloth of the present embodiment is a glass cloth obtained by weaving glass threads composed of a plurality of glass filaments as warp threads and weft threads, and one of the warp threads and the weft threads has a SiO ₂ composition amount of 98 to 100 mass. A glass filament containing a glass filament of%, and the other of the warp and the weft has a SiO ₂ composition of 45 to 60% by mass and a B ₂ O ₃ composition of 15 to 30% by mass. The average filament diameters of the warp and the glass filaments constituting the weft are independently 3 to 10 μm, and the numbers of filaments of the warp and the weft are independent of each other. The number of threads is 20 to 300, the driving densities of the warp and the weft are independently 20 to 140 threads / inch, the thickness of the glass cloth is 8 to 100 μm, and the strength of the glass cloth is strong. A silane coupling having a heat loss value of 0.2% by mass or more and 1.0% by mass or less, a dielectric constant of the glass cloth of more than 3.8 and 4.4 or less, and an unsaturated double-bonding group. The surface of the glass thread is treated with an agent.

When the _{amount of SiO 2} composition is 98 to 100% by mass, the dielectric constant is lowered, but the drilling workability of the substrate tends to be deteriorated. The Vickers hardness of general glass is ^{about 640 kgf / mm 2} , but the Vickers hardness of glass with a SiO ₂ composition of almost 100% is ^{about 820 kgf / mm 2} , and the tip of the drill tip is significantly worn during drilling. In some cases. Therefore, the inner wall of the hole is rough and a dirty drill hole is formed, and the glass / resin interface on the inner wall of the hole is likely to be peeled off (peeled portion). When the copper plating treatment or the like is performed, the plating liquid tends to permeate into the glass cloth from the peeled portion, and the insulation reliability tends to decrease.

Further, when the SiO ₂ composition amount is 98 to 100% by mass, the bending resistance of the glass filament is significantly lowered, and the glass filament may be cracked or broken. Broken or broken glass filaments contribute to the fluffing of the glass cloth. Since such fluffing can occur in the warping, weaving, and fiber-spreading steps of the glass cloth, it was decided to manufacture a glass cloth having less fluffing by using a glass filament having _{a SiO 2 composition amount of 98 to 100% by mass.} Is not easy. In particular, in the case of warp yarns, in the warping and weaving processes, the glass yarns come into contact with many members such as rolls, so that fluffing is more likely to occur. Further, in prepreg applications, such a glass filament having low bending resistance may cause fluffing during processing, which tends to be inferior in practicality. The fluffing increases the probability that the fluffing portion collides with the conductive layer when the laminated board is produced, which also causes poor protrusions and poor interlayer insulation. Therefore, _{it is assumed that 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 the present embodiment, one of the warp and the weft _{is a glass thread containing a glass filament having a SiO 2} composition amount of 98 to 100% by mass, and the other of the warp and the weft is a SiO ₂ composition amount. A glass yarn containing a glass filament having a B ₂ O ₃ composition of 15 to 30% by mass, and the surface of the glass yarn is coated with a silane coupling agent having an unsaturated double-bonding group. By treating and setting the strong heat loss value of the glass cloth to 0.2% by mass or more and 1.0% by mass or less, it is possible to improve the bending resistance of the glass filament while taking advantage of the low dielectric constant. It is possible to provide a glass cloth capable of producing a substrate having a lower dielectric constant than the conventional one and having excellent insulation reliability. Further, 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]
In the present embodiment, one of the warp and the weft _{is a glass yarn containing a glass filament having a SiO 2} composition amount of 98 to 100% by mass (hereinafter, also referred to as “glass filament A”), and the warp and the weft On the other hand, it is a glass thread containing a glass filament (hereinafter, also referred to as "glass filament B") having _{a SiO 2} composition amount of 45 to 60% by mass and a B ₂ O _{3 composition amount of 15 to 30% by mass.} .. In this embodiment, one of the warp and the weft is a glass thread made of glass filament A, the other of the warp and the weft is a glass thread made of glass filament B, and one of the warp and the weft is glass. It is a glass thread composed of a filament A and a glass filament B, and the other of the warp and the weft is a glass thread made of the glass filament A or a glass thread made of the glass filament B, and both the warp and the weft are glass. A mode in which the glass thread is composed of the filament A and the glass filament B is also included.

[Glass filament A]
_{The SiO 2} composition of the glass filament A is 98 to 100% by mass, preferably 98 to 99.95% by mass, and more preferably 98 to 99% by mass. When the SiO ₂ composition amount is 98% by mass or more, the dielectric constant and the dielectric loss tangent tend to be further reduced. Further, when the SiO ₂ composition amount is 98% by mass or more, air contamination during glass melt spinning can be suppressed, and the generation of hollow fibers can be suppressed. By reducing the number of hollow fibers, the insulation reliability of the substrate tends to be further improved. Further, when the SiO ₂ composition amount is 99.95% by mass or less, the bending resistance and brittleness of the glass yarn tend to be further improved. As a result, the drilling workability of the substrate is further improved, and the glass thread breakage is less likely to occur at the time of opening the fiber after processing the glass cloth and at the time of washing with water, and the amount of fluff of the glass cloth tends to decrease. .. By using such a glass cloth, the dielectric constant is further lowered, the insulation reliability is improved due to the reduction of hollow threads, the insulation reliability is improved due to the improvement of the drilling workability of the substrate, and the fluffing is reduced. It is possible to improve the insulation reliability (prevention of plating penetration, protrusion failure, interlayer insulation failure, etc.). The _{amount of SiO 2} composition can be adjusted according to the amount of raw material used for producing the glass filament.

Further, the glass filament A may have other compositions in addition to _{SiO 2.} Other compositions are not particularly limited, and examples thereof 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. Be done.

[Glass filament B]
_{The SiO 2} composition amount of the glass filament B is 45 to 60% by mass, preferably 50 to 60% by mass, and more preferably 51 to 56% by mass. _{The B 2} O ₃ composition of the glass filament B is 15 to 30% by mass, preferably 20 to 30% by mass, and more preferably 21 to 25% by mass. When the SiO ₂ composition amount is 60% or less and the B ₂ O ₃ composition amount is 15% by mass or more, the glass melt viscosity is lowered and the glass yarn is easily pulled, so that the generation of hollow yarn can be suppressed. Also, the dielectric constant decreases. Further, when the SiO ₂ composition amount is 45% or more and the B ₂ O ₃ composition amount is 30% by mass or less, the moisture absorption resistance is further improved when the surface treatment is applied. On the other hand, when the B ₂ O ₃ composition amount is less than 15% by mass, the number of hollow threads increases, and the insulation reliability decreases accordingly. Further, when the B ₂ O ₃ composition amount is further reduced to the E glass composition amount, the number of hollow threads tends to decrease, but the dielectric constant increases. Further, when the B ₂ O ₃ composition amount exceeds 30% by mass, the amount of fluff increases and the amount of moisture absorption increases, so that the insulation reliability decreases. The _{amount of B 2} O ₃ composition can be adjusted according to the amount of raw material used for producing the glass filament.

Further, the glass filament B may have other compositions in addition to _{SiO 2} and B ₂ O _3. Other compositions are not particularly limited, and examples thereof include Al ₂ O ₃ , CaO, MgO, TiO ₂ , Na ₂ O, K ₂ O, Sr ₂ O ₃ , Fe ₂ O _{3, and the} like.

_{The Al 2} O ₃ composition amount in the glass filament B is preferably 11 to 16% by mass, more preferably 12 to 16% by mass. When the Al ₂ O ₃ composition amount is within the above range, the productivity of the yarn tends to be further improved.

The CaO composition content in the glass filament B is preferably 4 to 8% by mass, more preferably 6 to 8% by mass. When the CaO composition amount is within the above range, the productivity of the yarn tends to be further improved.

[Average filament diameter of glass filament]
The average filament diameter of the glass filaments constituting the warp and weft is independently 3 to 10 μm, preferably 3.5 to 9.5 μm. When the average filament diameter of the glass filament is within the above range, the workability tends to be further improved when the obtained substrate is processed by a mechanical drill. In particular, setting the average filament diameter of the glass filament to 9.5 μm or less means that the area of contact between the matrix resin and the glass filament per unit volume increases, so that the ignition loss value is set to 0.2% by mass or more. This is preferable because the effects described below tend to be more pronounced. When the warp or weft is a glass thread made of glass filament A or B, the average filament diameter is the average filament diameter of the glass filaments A or B constituting the glass thread, and the warp or weft is glass. In the case of a glass thread composed of filaments A and B, the average filament diameter is the average filament diameter of the glass filaments A and B constituting the glass thread.

In particular, the average filament diameter of the glass filament A is preferably 4 to 10 μm, more preferably 6 to 10 μm, and even more preferably 7.5 to 10 μm. When the average filament diameter of the glass filament A is 4 μm or more, the thread breakage of the glass filament A is further suppressed, the amount of fluff of the glass cloth is reduced, and the insulation reliability due to the reduction of fluff tends to be further improved. .. Further, since the area of contact between the matrix resin and the glass filament per unit volume increases when the average filament diameter of the glass filament A is 10 μm or less, the ignition loss value is set to 0.2% by mass or more, which will be described later. The effect tends to be more pronounced.

The average filament diameter of the glass filament B is preferably 3 to 9 μm, more preferably 4 to 8 μm, and even more preferably 5 to 7 μm. When the average filament diameter of the glass filament B is 3 μm or more, the processability of the obtained substrate tends to be further improved. Since the area of contact between the matrix resin and the glass filament per unit volume increases when the average filament diameter of the glass filament B is 9 μm or less, the effect described later by setting the ignition loss value to 0.2% by mass or more can be obtained. It tends to be expressed more widely.

[Number of filaments of glass filament]
The number of filaments of the glass filaments constituting the warp and weft are independently 20 to 300, preferably 20 to 200. When the number of filaments of the glass filament is within the above range, the workability tends to be further improved when the obtained substrate is processed by a mechanical drill. When the warp or weft is a glass thread made of glass filaments A or B, the number of filaments is the number of glass filaments A or B constituting the glass thread, and the warp or weft is glass filament A or. In the case of a glass thread made of B, the number of filaments is the total number of glass filaments A and B constituting the glass thread.

In particular, when the warp or weft is a glass yarn made of glass filament A, the number of filaments of glass filament A is preferably 20 to 250, more preferably 50 to 200, and even more preferably 75. ~ 150 pieces. When the number of filaments of the glass filament A is 20 or more, the yarn breakage of the glass filament A is further suppressed, the amount of fluff of the glass cloth is reduced, and the insulation reliability due to the reduction of fluff tends to be further improved. .. Further, when the number of filaments of the glass filament A is 250 or less, there is a tendency that a finer glass thread can be realized while suppressing fluffing in consideration of the filament diameter.

When the warp or weft is a glass yarn made of glass filament B, the number of filaments of the glass filament B is preferably 50 to 300, more preferably 100 to 275, and even more preferably 150. ~ 250 pieces. When the number of filaments of the glass filament B is 50 or more, the processability of the obtained substrate tends to be further improved. When the number of filaments of the glass filament B is 300 or less, a finer glass thread tends to be realized in consideration of the filament diameter.

[Driving density]
The driving densities of the warp threads and the weft threads constituting the glass cloth are independently 20 to 140 threads / inch, preferably 30 to 130 threads / inch, and more preferably 40 to 120 threads / 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 (Metsuke)]
The cloth weight (basis weight) of the glass cloth is preferably 6 to 100 g / m ² , and more preferably 7 to 90 g / m ² .

[Woven 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. Of 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 hydrophilic functional groups are less likely to be generated after the reaction with the matrix resin, and the insulation reliability is further improved. ..

The silane coupling agent having an unsaturated double bond group is not particularly limited, and examples thereof include compounds represented by the following general formula (1). By using a silane coupling agent having an unsaturated double bond group, the plating solution penetration property, insulation reliability, and fluffing quality after drilling of glass cloth having _{a SiO 2 composition amount of 98 to 100% by mass can be improved.} 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-bonding groups, Y is an alkoxy group independently, n is an integer of 1 or more and 3 or less, and R is. , Each independently 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 above-mentioned alkoxy group, but an alkoxy group having 5 or less carbon atoms is preferable for stabilizing the glass cloth.

The silane coupling agent that can be specifically used is not particularly limited, but 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, N-β -(N-di (vinylbenzyl) aminoethyl) -N-γ- (N-vinylbenzyl) -γ-aminopropyltrimethoxysilane and its hydrochloride, vinyltrimethoxysilane, methacryloxypropyltrimethoxysilane, methacryloxy Known substances such as octyloxypropyltrimethoxysilane and acryloxypropyltrimethoxysilane can be mentioned. The silane coupling agent tends to have excellent reactivity with glass threads (glass filaments) of glass cloth and matrix resins of substrates, particularly radical polymerization resins. Therefore, it tends to be possible to suppress a decrease in insulation reliability due to the resin and the glass cloth being easily peeled off at the interface, and it is possible to suppress a decrease in insulation reliability due to the plating liquid permeating into the glass cloth.

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

[Ignition loss value]
The ignition loss value of the glass cloth is 0.2% by mass or more, preferably 0.3% by mass or more, and more preferably 0.4% by mass or more. The upper limit of the ignition loss value of the glass cloth is 1.0% by mass or less, preferably 0.9% by mass or less, and more preferably 0.8% by mass or less. When the ignition loss value of the glass cloth is 0.2% by mass or more, the plating liquid penetration property, insulation reliability, and fluffing quality after drilling 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. Further, when the ignition loss value of the glass cloth is 1.0% 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" referred to 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 allowing to cool, weigh the glass cloth 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 a muffle furnace, the glass cloth is transferred to a desiccator, left for 20 minutes, and allowed to cool to room temperature. After allowing to cool, weigh the glass cloth in units of 0.1 mg or less. The amount of glass cloth treated with the silane coupling agent 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 more and 4.4 or less, preferably 3.8 or more and 4.2 or less. The dielectric constant of the glass cloth can be measured by the method described in Examples.

[Manufacturing method of glass cloth]
The method for producing the glass cloth of the present embodiment is not particularly limited, and 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% by mass is used. The strong heat loss value is obtained by the fixing step of fixing the silane coupling agent to the surface of the glass filament by heat drying and washing at least a part of the silane coupling agent fixed to the surface of the glass filament with high-pressure spray water or the like. Examples thereof include a method having a preparation step of adjusting the adhesion amount of the silane coupling agent so as to be 0.2 to 1.0% by mass.

As the solvent for dissolving or dispersing the silane coupling agent, either water or an organic solvent can be used, but from the viewpoint of safety and protection of the global environment, it is preferable to use water as the main solvent. As a method of obtaining a treatment liquid using water as a main solvent, a method of directly adding a silane coupling agent to water, a method of dissolving the silane coupling agent in a water-soluble organic solvent to prepare an organic solvent solution, and then using the organic solvent solution. Any method of adding water to water is preferable. It is also possible to use a surfactant in combination in order to improve the water dispersibility and stability of the silane coupling agent in the treatment liquid.

The coating step, the fixing step, and the preparation step are preferably performed on the glass cloth after the weaving step. Further, if necessary, a fiber opening step of opening the glass yarn of the glass cloth may be provided after the weaving process. When the preparation step is performed after the weaving step, the adjusting step may also serve as the fiber opening step. The composition of the glass cloth usually does not change before and after opening the fiber.

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 thread by the above manufacturing method.

The methods for applying the treatment liquid to the glass cloth include (a) a method in which the treatment liquid is stored in a bath and the glass cloth is immersed and passed through (hereinafter referred to as "immersion method"), (b) a roll coater, a die coater, and the like. Alternatively, a method of directly applying the treatment liquid to the glass cloth with a gravure coater or the like is possible. When applying by the dipping method of (a) above, it is preferable to select the immersion time of the glass cloth in the treatment liquid to be 0.5 seconds or more and 1 minute or less.

Further, as a method of applying the treatment liquid to the glass cloth and then heating and drying the solvent, known methods such as hot air and electromagnetic waves can be mentioned.

The heating and drying temperature is preferably 90 ° C. or higher, more preferably 100 ° C. or higher so that the reaction between the silane coupling agent and the glass is sufficiently carried out. Further, in order to prevent deterioration of the organic functional group of the silane coupling agent, the temperature is preferably 300 ° C. or lower, more preferably 200 ° C. or lower.

The method for opening the fiber in the fiber opening step is not particularly limited, and examples thereof include a method for opening the glass cloth with spray water (high pressure water opening), vibro washer, ultrasonic water, mangle, and the like. .. In the fiber-spreading process, in _{the case of glass cloth having a SiO 2} composition amount of 98 to 100% by mass, fluffing is likely to occur. On the other hand, when the ignition loss value of the glass cloth of the present embodiment is 0.12% by mass or more, fluffing 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 the friction of the contact member when weaving the glass yarn, optimizing the sizing agent and increasing the amount of adhesion. .. By lowering the tension applied to the glass cloth during the fiber opening process, the air permeability tends to be made smaller.

It may have an arbitrary step even after the fiber opening step. The arbitrary process is not particularly limited, and examples thereof include a slit processing process.

After the glass cloth is surface-treated, a matrix resin is applied to produce a prepreg. The storage period between the surface treatment of the glass cloth and the application of the matrix resin is preferably 2 years or less. The storage temperature is preferably 10 to 40 ° C. When the storage temperature is 30 ° C. or lower, the deactivation of the unsaturated double bond group 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. Further, when the storage period is 2 years or less, the silane coupling agents react with each other due to the water adhering to the glass surface, and there is a tendency that it is possible to suppress the increase in the focusing property of the glass filament bundle. This tends to improve the permeability of the matrix resin.

[Prepreg]
The prepreg of the present embodiment has the above glass cloth and a matrix resin impregnated in the glass cloth. As a result, it is possible to provide a prepreg that is thin, has a low dielectric constant, and has improved insulation reliability by improving insulation reliability and moisture absorption resistance related to each of 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, but for example, a) a compound having an epoxy group, 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 cures a compound having at least one of the above, etc., 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, a phosphorus compound, etc. Resin; b) A radical polymerization type curable resin in which a compound having at least one of an allyl group, a methacryl group, and an acrylic group is cured using a thermosetting catalyst or a photodegradable catalyst as a reaction initiator; c. ) Maleimide triazine resin in which a compound having a cyanate group and a compound having a maleimide group are reacted and cured; d) A thermosetting polyimide resin in which a maleimide compound and an amine compound are reacted and cured; e) Benzo Examples thereof include a benzoxazine resin in which a compound having an oxazine ring is crosslinked and cured by heat polymerization.

The thermoplastic resin is not particularly limited, but for example, polyphenylene ether, modified polyphenylene ether, polyphenylene sulfide, polysulfone, polyether sulphon, polyarylate, aromatic polyamide, polyether ether ketone, thermoplastic polyimide, insoluble polyimide, etc. Examples thereof include polyamide-imide and fluororesin. Further, the thermosetting resin and the thermoplastic resin may be used in combination.

[Printed circuit board]
The printed wiring board of this embodiment has the above-mentioned prepreg. As a result, it is possible to provide a printed wiring board having a low dielectric constant and improved insulation reliability.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.

(Example 1)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition of 53% by mass and B ₂ O ₃ Using a warp yarn (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 23% by mass, glass cloth (thickness 78 μm, cloth weight 70 g / m ² ). Was woven. The obtained glass cloth is immersed in a treatment solution in which a hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Toray Corning Co., Ltd .; Z6032) is dispersed in water. And dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.22% by mass.

(Example 2)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition of 53% by mass and B ₂ O ₃ Using a warp yarn (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 23% by mass, glass cloth (thickness 78 μm, cloth weight 70 g / m ² ). Was woven. The obtained glass cloth is immersed in a treatment solution in which a hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Toray Corning Co., Ltd .; Z6032) is dispersed in water. And dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.32% by mass.

(Example 3)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition of 53% by mass and B ₂ O ₃ Using a warp yarn (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 23% by mass, glass cloth (thickness 78 μm, cloth weight 70 g / m ² ). Was woven. The obtained glass cloth is immersed in a treatment solution in which a hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Toray Corning Co., Ltd .; Z6032) is dispersed in water. And dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.85% by mass.

(Example 4)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition of 59% by mass and B ₂ O ₃ Using a warp yarn (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 16% by mass, glass cloth (thickness 78 μm, cloth weight 70 g / m ² ). Was woven. The obtained glass cloth is immersed in a treatment solution in which a hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Toray Corning Co., Ltd .; Z6032) is dispersed in water. And dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.22% by mass.

(Example 5)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition of 53% by mass and B ₂ O ₃ Using a warp yarn (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 23% by mass, glass cloth (thickness 78 μm, cloth weight 70 g / m ² ). Was woven. The obtained glass cloth was immersed in a treatment liquid in which methacryloxypropyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd .; Z6030) was dispersed in water, and dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.22% by mass.

(Example 6)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition of 53% by mass and B ₂ O ₃ Using a warp yarn (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 23% by mass, glass cloth (thickness 78 μm, cloth weight 70 g / m ² ). Was woven. The obtained glass cloth was mixed with a hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd .; Z6032) and methacryloxypropyltrimethoxysilane (Toredau). Co., Ltd .; Z6030) was immersed in a treatment liquid dispersed in water and dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.22% by mass.

(Example 7)
Weft threads made of glass filaments with a SiO ₂ composition of 98.5% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition amount 53% by mass and B ₂ O ₃ Using a warp yarn (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 23% by mass, glass cloth (thickness 78 μm, cloth weight 70 g / m ² ). Was woven. The obtained glass cloth is immersed in a treatment solution in which a hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Toray Corning Co., Ltd .; Z6032) is dispersed in water. And dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.22% by mass.

(Comparative Example 1)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition of 53% by mass and B ₂ O ₃ Using a warp yarn (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 23% by mass, glass cloth (thickness 78 μm, cloth weight 70 g / m ² ). Was woven. The obtained glass cloth is immersed in a treatment solution in which a hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Toray Corning Co., Ltd .; Z6032) is dispersed in water. And dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.19% by mass.

(Comparative Example 2)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition of 53% by mass and B ₂ O ₃ Using a warp yarn (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 23% by mass, glass cloth (thickness 78 μm, cloth weight 70 g / m ² ). Was woven. The obtained glass cloth was immersed in a treatment solution in which N-phenyl-aminopropyltrimethoxysilane (manufactured by Shinetsu Silicone Co., Ltd .; KBM573) was dispersed in water, and dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.22% by mass.

(Comparative Example 3)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition of 53% by mass and B ₂ O ₃ Using a warp yarn (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 23% by mass, glass cloth (thickness 78 μm, cloth weight 70 g / m ² ). Was woven. The obtained glass cloth is immersed in a treatment solution in which a hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Toray Corning Co., Ltd .; Z6032) is dispersed in water. And dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 1.1% by mass.

(Comparative Example 4)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments 9 μm, number of filaments 100, driving density 54 / inch), SiO ₂ composition amount 61% by mass and B ₂ O ₃ ^{A glass cloth (thickness 78 μm, cloth weight 70 g / m 2} ) using a warp (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 14% by mass. Was woven. The obtained glass cloth is immersed in a treatment solution in which a hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Toray Corning Co., Ltd .; Z6032) is dispersed in water. And dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.22% by mass.

(Comparative Example 5)
Weft _{threads made of glass filaments with a SiO 2} composition of 99.9% by mass (average filament diameter of glass filaments: 9 μm, number of filaments: 100, driving density: 54 / inch), SiO ₂ composition of 46% by mass and B ₂ O ₃ ^{A glass cloth (thickness 78 μm, cloth weight 70 g / m 2} ) using a warp (average filament diameter of glass filament 6 μm, number of filaments 200, driving density 61 / inch) composed of glass filaments having a composition amount of 31% by mass. Was woven. The obtained glass cloth is immersed in a treatment solution in which a hydrochloride of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane (manufactured by Toray Corning Co., Ltd .; Z6032) is dispersed in water. And dried by heating. Next, high-pressure water defibration was carried out by spraying, and the product was obtained by heating and drying. The ignition loss value of the glass cloth was 0.22% by mass.

<Evaluation method of ignition loss value of glass cloth>
The ignition loss value was measured according to the method described in JIS R 3420. 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 allowing to cool, the weight of the glass cloth was measured in units of 0.1 mg or less. The glass cloth was then heated in a muffle furnace at about 625 ° C. for 20 minutes. After heating in a muffle furnace, the glass cloth was transferred to a desiccator and allowed to cool to room temperature. After allowing to cool, the weight of the glass cloth was measured in units of 0.1 mg or less. The weight change before and after heating of the muffle furnace was measured, and the ignition loss value was calculated as the amount of the treatment agent adhered.

<Evaluation method of glass cloth thickness>
According to JIS R 3420 7.10, the spindle was gently rotated using a micrometer to bring it into light contact parallel to the measurement surface. I read the scale after the ratchet made three sounds.

<Evaluation of prepreg fluff (evaluation of bending resistance)>
A polyphenylene ether resin varnish (a mixture of 30 parts by mass of a modified polyphenylene ether resin, 10 parts by mass of triallyl isocyanurate, 60 parts by mass of toluene, and 0.1 parts by mass of a catalyst) was added to the glass cloths obtained in the above Examples and Comparative Examples. It was impregnated and dried at 120 ° C. for 2 minutes to obtain a prepreg. The resin content of this prepreg was adjusted to 50% by mass. Next, a small piece sample of 100 mm × 100 mm at an arbitrary location was cut out, and the number of protrusions was visually determined.

<How to make a substrate>
A polyphenylene ether resin varnish (a mixture of 30 parts by mass of a modified polyphenylene ether resin, 10 parts by mass of triallyl isocyanurate, 60 parts by mass of toluene, and 0.1 parts by mass of a catalyst) was added to the glass cloths obtained in the above Examples and Comparative Examples. It was impregnated and dried at 120 ° C. for 2 minutes to obtain a prepreg. This prepreg was overlaid, and a copper foil having a thickness of 12 μm was further overlaid on 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>
As described above, a substrate was prepared 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 permittivity, the permittivity of the glass cloth was calculated based on the volume fraction of the glass cloth and the resin permittivity 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 are arranged at intervals of 0.15 mm is prepared on the copper foils on both sides of the substrate to prepare 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 the change in resistance value was measured. At this time, when the resistance became less than 1 MΩ within 500 hours after the start of the test, it was counted as an insulation defect. The same measurement was performed on 10 samples, and the ratio of the samples that did not cause insulation failure was calculated.

Table 1 summarizes the evaluation results of the glass cloths shown in Examples and Comparative Examples.

It was found that the substrate obtained by using the glass cloth of the example had a low dielectric constant and was extremely excellent in insulation reliability.

The glass cloth of the present invention has industrial applicability as a base material used for a printed wiring board used in the electronic and electrical fields.

Claims (7)

A glass cloth made by weaving glass threads composed of a plurality of glass filaments as warp threads and weft threads.
One of said warp and said weft, a glass yarn SiO ₂ composition amount is made of glass filaments is 98 to 100 wt%,
The other of the warp and the weft, a SiO ₂ composition weight 45 to 60 wt%, a glass yarn B ₂ O ₃ composition amount is made of glass filaments is 15 to 30 wt%,
The average filament diameters of the warp threads and the glass filaments constituting the weft threads are independently 3 to 10 μm.
The number of filaments of the warp and the weft is 20 to 300 independently.
The driving densities of the warp and the weft are independently 20 to 140 threads / inch.
The thickness of the glass cloth is 8 to 100 μm.
The ignition loss value of the glass cloth is 0.2% by mass or more and 1.0% by mass or less.
The dielectric constant of the glass cloth is more than 3.8 and 4.4 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 0.3% by mass or more and 0.8% by mass or less.
The glass cloth according to claim 1. The surface of the glass yarn was treated with two or more kinds of the silane coupling agents having different molecular weights.
The glass cloth according to claim 1 or 2. One of said warp and said weft, the SiO ₂ composition weight of glass strands consisting of glass filaments is 98 to 99.95 wt%,
The glass cloth according to any one of claims 1 to 3. The other of the warp and the weft, the a SiO ₂ composition weight 50-60 wt%, the B ₂ O ₃ composition weight of glass strands consisting of glass filaments is 20 to 30 wt%,
The glass cloth according to any one of claims 1 to 4. The glass cloth according to any one of claims 1 to 5.
The glass cloth is impregnated with a matrix resin.
Prepreg. Having the prepreg according to claim 6.
Printed wiring board.