Glass cloth, prepreg and printed circuit board

Abstract

The invention discloses glass cloth, prepreg and a printed circuit board. [Problem] To provide a glass cloth capable of achieving a prepreg and a printed wiring board having excellent dimensional stability and capable of suppressing the occurrence of pinholes in the prepreg. [Solution] The glass cloth contains glass yarns as warp yarns and weft yarns, the weaving density of the warp yarns and the weft yarns is 50-110 / 25 mm, the thickness of the glass cloth is 20 [mu] m or less, and the average gap intervals in the weft yarn direction and the warp yarn direction in which meshes are formed are 162-240 [mu] m and 65-200 [mu] m, respectively.

Description

Technical Field

[0001] The present invention relates to glass cloth, prepreg and printed circuit board, etc. Background Art

[0002] In recent years, with the miniaturization of electronic devices, there has been a strong demand for lightweight printed circuit boards. To achieve the reduction in weight of materials used in printed circuit boards, there is also a demand for the glass cloth contained in prepregs to be lightweight.

[0003] Patent Documents 1 to 4 report methods for producing prepregs using low-quality glass cloth. Patent Documents 1 to 4 all attempt to suppress the generation of pinholes in the prepreg by controlling the fineness of the glass cloth or the gap between the yarn widths.

[0004] Patent Document 5 reports a method for producing a printed circuit board using low-quality glass cloth. Patent Document 6 also reports a method for producing a printed circuit board using low-quality glass cloth, attempting to improve the dimensional stability and mechanical properties of the printed circuit board by controlling the "surface glass yarn coverage."

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2021-075805

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2017-043873

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2018-021274

[0010] Patent Document 4: WO2019 / 163159

[0011] Patent Document 5: WO2015 / 033731

[0012] Patent Document 6: Japanese Patent Application Laid-Open No. 2005-213656 Summary of the Invention

[0013] Problems to be solved by the invention

[0014] In recent years, the demand for higher functionality, smaller size, and lighter weight in digital devices has led to further miniaturization and thinning of printed circuit boards, as well as finer and higher-density wiring. Consequently, glass cloth and prepreg used in applications such as printed circuit boards are being required to achieve both thinner films and greater dimensional stability.

[0015] In order to reduce the thickness of glass cloth and prepreg, it is generally advantageous to use glass yarn having a small TEX value (mass per 1000 m of glass yarn) and to weave the glass yarn at a high weaving density.

[0016] Here, the gaps between the warp and weft yarns in a glass cloth are called "basket holes." Because these basket holes are not fully filled with thermosetting resin, defects called "pinholes" may occur in prepregs. It is known that controlling the weaving density to a high level can provide advantages such as easily suppressing the occurrence of prepreg defects (pinholes) and making the glass cloth less likely to wrinkle during handling.

[0017] However, the present inventors have found that if the weaving density is controlled to a high density, a difference in the amount of thermosetting resin tends to occur between the front and back sides of the prepreg, and furthermore, the dimensional stability of both the prepreg and the resulting printed wiring board deteriorates.

[0018] Therefore, an object of the present invention is to provide a glass cloth capable of realizing a prepreg and a printed wiring board having excellent dimensional stability and capable of suppressing the occurrence of pinholes in the prepreg.

[0019] Another object of the present invention is to provide a prepreg, a printed wiring board, and the like obtained using the glass cloth.

[0020] Solutions for solving problems

[0021] One embodiment of the present invention is as follows.

[0022] [1] A glass cloth comprising glass yarns as warp yarns and weft yarns,

[0023] The weaving density of the warp yarn and the weft yarn is 50 to 110 yarns / 25 mm.

[0024] The thickness of the glass cloth is 20 μm or less.

[0025] The average gap intervals in the weft direction and the warp direction forming the mesh holes are 162 to 240 μm and 65 to 200 μm respectively.

[0026] [2] The glass cloth according to item 1, wherein the glass yarn has a TEX value of 0.2 to 2.0 g / 1000 m.

[0027] [3] The glass cloth according to item 1 or 2, wherein the average area of ​​the holes is 15,000 to 45,000 μm 2 .

[0028] [4] The glass cloth according to any one of items 1 to 3, wherein the glass cloth has an area of ​​15,000 to 45,000 μm 2 The aforementioned hole.

[0029] [5] The glass cloth according to any one of items 1 to 4, wherein the glass yarn comprises a plurality of glass filaments.

[0030] The diameter of the glass filaments in the glass yarn is 2.0 to 4.5 μm, and the number of the glass filaments is 10 to 50.

[0031] [6] The glass cloth according to any one of items 1 to 5, wherein the ratio of the holes (short side / long side) is 0.4 to 0.8.

[0032] [7] The glass cloth according to any one of items 1 to 6, wherein the average fineness of the warp yarns is 70 to 110%, and / or the average fineness of the weft yarns is 90 to 140%.

[0033] [8] The glass cloth according to any one of items 1 to 7, wherein the ratio of the glass yarns (weaving density of warp yarns / weaving density of weft yarns) is less than 1.0.

[0034] [9] The glass cloth according to any one of items 1 to 8, wherein the glass yarn is surface-treated with a silane coupling agent.

[0035]

[10] The glass cloth according to item 9, wherein the silane coupling agent comprises a silane coupling agent represented by the following general formula (1).

[0036] X(R) 3-n SiE n …(1)

[0037] (wherein, X is an organic functional group having one or more amino groups, an organic functional group having one or more unsaturated double bond groups having free radical reactivity, or an organic functional group having both one or more amino groups and one or more unsaturated double bond groups having free radical reactivity;

[0038] Y is independently an alkoxy group; n is an integer from 1 to 3; and R is independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group.

[0039]

[11] A prepreg comprising the glass cloth according to any one of items 1 to 10 and a thermosetting resin.

[0040]

[12] A printed circuit board comprising the prepreg according to item 11.

[0041]

[13] An integrated circuit comprising the printed circuit board described in item 12.

[0042]

[14] An electronic device comprising the printed circuit board described in item 12.

[0043] Effects of the Invention

[0044] According to the present invention, it is possible to provide a glass cloth capable of realizing a prepreg and a printed wiring board having excellent dimensional stability and capable of suppressing the generation of pinholes in the prepreg.

[0045] Furthermore, the present invention can provide a prepreg, a printed wiring board, an integrated circuit, and an electronic device obtained by using the glass cloth. DETAILED DESCRIPTION

[0046] Hereinafter, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described. However, the present invention is not limited to this embodiment, and therefore various modifications can be made without departing from the spirit of the present invention.

[0047] In this specification, when there are multiple structures represented by the same symbol in the same formula, as long as there is no additional provision, the structure can be selected independently of each other, and in addition, they can be the same or different from each other. When there are multiple structures represented by the same symbol in mutually different formulas, as long as there is no additional provision, the structure can be selected independently of each other, and in addition, they can be the same or different from each other. In this specification, the upper limit or lower limit in the numerical range of stage-by-stage recording can be replaced by the upper limit or lower limit in the numerical range of corresponding other stage-by-stage recordings, and then, can be replaced by the corresponding value recorded in the embodiment.

[0048] In this specification, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes as long as the function of the process can be achieved.

[0049] [First embodiment]

[0050] The glass cloth of this embodiment is a glass cloth containing glass yarns as warp yarns and weft yarns.

[0051] The weaving density of warp and weft yarns is 50 to 110 yarns / 25mm.

[0052] The thickness of the glass cloth is less than 20 μm.

[0053] The average gap intervals in the weft direction and the warp direction forming the mesh holes are 162 to 240 μm and 65 to 200 μm respectively.

[0054] While controlling the weaving density of glass cloth to a high density is advantageous in terms of easily suppressing defects (pinholes) in prepregs, the present inventors have discovered that this is disadvantageous in that differences in the amount of thermosetting resin tend to occur between the front and back sides of the prepreg. Furthermore, the present inventors have discovered that controlling the weaving density of glass cloth to a high density tends to cause differences in the amount of thermosetting resin between the front and back sides of the prepreg, and the number of weaving intersections tends to increase. In this case, the influence of the residual deformation margin for stretching the glass cloth in the warp and weft directions increases, resulting in a negative impact on the dimensional stability of the prepreg and printed wiring board.

[0055] According to this embodiment, which was realized based on the above-mentioned concept of the present inventors, by appropriately adjusting the weaving density of the glass yarns in the glass cloth and appropriately spreading the warp yarns, it is possible to achieve both suppression of pinhole formation in the prepreg and improvement of dimensional stability. The glass cloth according to this embodiment can also meet the demand for thinner films.

[0056] [Glass cloth]

[0057] The glass cloth of this embodiment is a glass cloth comprising glass yarns as warp and weft, and in one embodiment, is a glass cloth woven with glass yarns comprising a plurality of glass filaments as warp and weft. The glass cloth is preferably surface-treated with a surface treatment agent described below.

[0058] 〔Glass Type〕

[0059] As the glass kind in the glass cloth, especially the glass kind in the glass cloth used by printed circuit board in glass cloth, be suitable for E glass (alkali-free glass), in addition, can be L glass, NE glass, D glass, L2 glass, S glass, T glass, silica glass and quartz glass etc..As glass kind, from the viewpoint that dielectric property is easily excellent, be preferably L glass, L2 glass, silica glass and quartz glass etc., wherein, more preferably silica glass and quartz glass.In addition, as glass kind, from the viewpoint that easily improves the dimensional stability of the laminated plate comprising glass cloth, be preferably S glass, T glass, silica glass and quartz glass, wherein, more preferably silica glass and quartz glass.

[0060] The amount of elements contained in glass can be measured using atomic absorption spectrometry, inductively coupled plasma (ICP) emission spectrometry, etc. For example, the amount of elements contained in each glass can be measured based on a calibration curve created using a device such as ICP-AES or ICP-MS using a sample with a known concentration.

[0061] [Dielectric constant and dielectric loss tangent of glass at 10 GHz]

[0062] The glass used in the glass cloth of this embodiment preferably has a dielectric constant of 7.0 F / m or less at 10 GHz, more preferably 6.0 or less, even more preferably 5.0 or less, even more preferably 4.5 or less, and particularly preferably 4.0 or less. Furthermore, the glass used in the glass cloth of this embodiment preferably has a dielectric loss tangent of 0.0070 or less at 10 GHz, more preferably 0.0065 or less, even more preferably 0.0045 or less, even more preferably 0.0030 or less, and particularly preferably 0.0020 or less. By setting the dielectric constant and / or dielectric loss tangent of the glass within the above ranges, transmission loss in the printed circuit board can be easily reduced.

[0063] Coefficient of Thermal Expansion (CTE) of Glass

[0064] The CTE of the glass used in the glass cloth of this embodiment is preferably 6.0 ppm / °C or less, more preferably 5.0 ppm / °C or less, even more preferably 3.5 ppm / °C or less, even more preferably 3.0 ppm / °C or less, and particularly preferably 2.0 ppm / °C or less. By adjusting the CTE of the glass within this range, the dimensional stability of the prepreg and printed wiring board can be easily improved.

[0065] 〔TEX value of glass yarn〕

[0066] The glass yarn used in the glass cloth of this embodiment preferably has a TEX value (mass per 1000 m of glass yarn) of 0.2 to 2.0 g / 1000 m. It is more preferably 0.3 to 1.8 g / 1000 m, even more preferably 0.4 to 1.6 g / 1000 m, even more preferably 0.5 to 1.4 g / 1000 m, and particularly preferably 0.6 to 1.2 g / 1000 m. By setting the TEX value of the glass yarn within this range, it is easier to achieve thin film thickness for the glass cloth, prepreg, and printed circuit board.

[0067] [Physical properties / composition of glass cloth]

[0068] The mass of the glass cloth of this embodiment can be 15.0 g / m2 in terms of mass per unit area according to JIS R3420. 2 From the viewpoint of reducing the thickness of the prepreg or printed wiring board containing the glass cloth, the mass of the glass cloth is preferably 12.0 g / m 2 Below, more preferably 11.0g / m 2 Below, more preferably 10.0 g / m 2 Below, particularly preferably 9.0 g / m 2 It should be noted that the lower limit of the mass per unit area of ​​the glass cloth may exceed 0 g / m 2 Or 0.1g / m2 above.

[0069] In order to control the quality of glass cloth to 15.0g / m 2 Hereinafter, as the glass yarn used in the warp and weft of the glass cloth, fine glass yarn is preferably used. The diameter of the glass filaments in the glass yarn (filament diameter) is preferably 2.0 to 4.5 μm, more preferably 2.5 to 4.0 μm, further preferably 3.0 to 3.9 μm, and particularly preferably 3.2 to 3.8 μm. If the filament diameter is 2.0 μm or more, it is easy to ensure the breaking strength of the filament, and therefore it is easy to suppress the generation of burrs. In addition, if the filament diameter is 4.5 μm or less, it is difficult to control the quality of the glass cloth to 15.0 g / m 2 the following.

[0070] In the glass cloth of this embodiment, the warp spread is preferably 70-110% and / or the weft spread is 90-140%. More preferably, the warp spread is 75-108% and / or the weft spread is 92-138%. Even more preferably, the warp spread is 80-106% and / or the weft spread is 94-135%. Even more preferably, the warp spread is 82-104% and / or the weft spread is 95-130%. Even more preferably, the warp spread is 85-103% and / or the weft spread is 96-128%. By controlling the warp and / or weft spread of the glass cloth within the above ranges, it is easier to achieve both wrinkle reduction during conveyance of the glass cloth and pinhole reduction in the prepreg. By making the spread below the upper limit of the above-mentioned range, it is easy to prevent the spread from becoming too high, and therefore it is easy to suppress wrinkles generated when transporting the glass cloth. On the other hand, by making the spread above the lower limit of the above-mentioned numerical range, it is easy to reduce the incidence of pinholes when making prepregs. The spread of the warp yarn can be adjusted in the fiber-spreading process of the glass cloth. In addition, it can be adjusted by using rollers to pressurize (press) the warp yarn with a specified load and flatten the warp yarn during warping. From the perspective of facilitating the adjustment of only the yarn width of the warp yarn, the spread of the warp yarn is preferably adjusted by flattening the warp yarn during warping. In this case, it is also easy to obtain the advantage of easily adjusting the spread of the warp yarn and the weft yarn to the above-mentioned range. The spread of the weft yarn can be adjusted by the fiber-spreading process of the glass cloth. The spread of the weft yarn can be easily adjusted to the above-mentioned range by, for example, adjusting the pressure during high-pressure fiber-spreading based on a spray.

[0071] The average spread of the glass cloth of this embodiment is preferably 80-150%, more preferably 82-140%, even more preferably 84-135%, even more preferably 85-130%, and particularly preferably 86-128%. By setting the average spread of the glass cloth within this range, it is easier to achieve both wrinkle reduction during conveyance of the glass cloth and pinhole reduction in the prepreg. The average spread of the glass cloth is expressed as the average of the warp and weft spreads.

[0072] The number of glass filaments used in the warp and weft of the glass cloth of this embodiment is preferably 10 to 50, more preferably 15 to 45, even more preferably 20 to 43, and particularly preferably 25 to 40. If the number of filaments is 50 or less, insufficient expansion rate can be easily prevented during flattening processes such as fiber-opening of the glass cloth. Furthermore, if the number of filaments is 10 or more, the formation of burrs in the glass cloth can be easily suppressed. Glass filaments within this range can be bundled when forming the glass yarn.

[0073] The weaving density of the warp and weft yarns of the glass cloth of this embodiment is in the range of 50 to 110 yarns / 25 mm. From the viewpoint of easily and significantly exhibiting the effects of the present invention, the weaving density of the warp and weft yarns of the glass cloth of this embodiment is preferably 55 to 100 yarns / 25 mm, more preferably 60 to 98 yarns / 25 mm, further preferably 65 to 96 yarns / 25 mm, and particularly preferably 70 to 95 yarns / 25 mm.

[0074] The weaving densities of the warp yarns and the weft yarns may be different from each other, the weaving density of the warp yarns may be greater than the weaving density of the weft yarns, and further, the weaving density of the warp yarns may be less than the weaving density of the weft yarns.

[0075] Regarding warp and / or weft, if the weaving density is less than 50 / 25mm, not only will pinholes of the prepreg be easily generated, but the rigidity of the glass cloth used as the core material of the resin substrate will also be easily insufficient. As a result, the stability of dimensional change is adversely affected. On the other hand, regarding warp and / or weft, if the weaving density exceeds 110 / 25mm, it will be difficult to adjust the average gap spacing in the weft direction and / or the warp direction to the scope of this embodiment. In this case, it is difficult to improve the dimensional stability of the resin substrate.

[0076] The overlapping warp and weft yarns of glass cloth, i.e., the weaving intersections, are where the glass yarns are bound. Slight residual deformation margins are observed at these weaving intersections. The present inventors have discovered that during glass cloth production, particularly when tension is applied to the glass cloth, the residual deformation margins near these weaving intersections can cause the glass cloth to stretch in the direction of the tension.

[0077] Therefore, the present inventors have discovered that reducing the number of weaving intersections in the glass cloth is effective for improving the dimensional stability of glass cloth, prepregs, and printed circuit boards. By setting the weaving density of the warp and weft yarns of the glass cloth within the aforementioned range, pinholes in the prepreg are prevented. When the weaving density is within the aforementioned upper limit, excellent dimensional stability is readily achieved.

[0078] The glass cloth of this embodiment preferably has a ratio (weaving density of warp yarns / weaving density of weft yarns) of less than 1.0. It is more preferably 0.9 or less, and particularly preferably 0.8 or less. This makes it easier to achieve both suppression of pinhole formation in the prepreg and improvement of the dimensional stability of the substrate.

[0079] The glass cloth of this embodiment has a thickness of 20 μm or less. The thickness of the glass cloth is more preferably 18 μm or less, further preferably 16 μm or less, even more preferably 13 μm or less, and particularly preferably 10 μm or less. By adjusting the thickness of the glass cloth to 20 μm or less, the desired thin film thickness can be fully met for the glass cloth, prepreg, and printed circuit board. It should be noted that the thickness of the glass cloth can be 3 μm or greater.

[0080] In this embodiment, "holes" refer to the spaces between the warp and weft yarns in the glass cloth. Furthermore, in this embodiment, "pinholes" refer to voids in the prepreg. These voids can occur, for example, when the holes are not filled with thermosetting resin.

[0081] Generally, if the average area of ​​the mesh holes is reduced, pinholes are less likely to form, but this makes it more difficult for the varnish to flow through the mesh holes from the front surface to the back surface of the glass cloth (or vice versa). In this case, the resin layers on both sides of the resulting prepreg are likely to have a difference in thickness, and thus dimensional stability is likely to be reduced.

[0082] In contrast, in the present embodiment, in order to prevent pinholes in the prepreg from occurring and to improve the dimensional stability of the substrate, the average gap spacing in the weft direction (also referred to as the gap spacing between adjacent warp yarns) and the average gap spacing in the warp direction (also referred to as the gap spacing between adjacent weft yarns) are adjusted to within the specified ranges by implementing the fiber opening method described later.

[0083] The average gap spacing in the weft direction is 162 to 240 μm. It is more preferably 165 to 235 μm, further preferably 170 to 230 μm, further preferably 172 to 225 μm, and particularly preferably 174 to 220 μm. If the average gap spacing in the weft direction exceeds the above range, the fiber opening of the glass cloth is likely to become insufficient, and therefore, pinholes are likely to form in the prepreg. If the average gap spacing in the weft direction is less than the above range, when making the prepreg, it is not easy for the varnish to flow from the surface of the glass cloth to the back (or from the back to the surface). In this case, in the resulting prepreg, the resin layers on both sides are likely to have a difference in thickness, and therefore, the dimensional stability is likely to be reduced.

[0084] The average gap spacing in the warp direction is 65 to 200 μm. It is more preferably 70 to 195 μm, further preferably 80 to 180 μm, further preferably 85 to 170 μm, and particularly preferably 90 to 160 μm. If the average gap spacing in the warp direction exceeds the above range, the fiber opening of the glass cloth is likely to become insufficient, and therefore, pinholes are likely to form in the prepreg. If the average gap spacing in the warp direction is less than the above range, it is difficult for the varnish to flow from the surface of the glass cloth to the back (or from the back to the surface) when making the prepreg. In this case, in the resulting prepreg, the resin layers on both sides are likely to have a thickness difference, and therefore, the dimensional stability is likely to be reduced.

[0085] The average gap interval in the weft direction may be the same as the average gap interval in the warp direction, the average gap interval in the weft direction may be larger than the average gap interval in the warp direction, and the average gap interval in the weft direction may be smaller than the average gap interval in the warp direction.

[0086] Comparing the average gap spacing in the weft direction with the average gap spacing in the warp direction, the larger of the two can be considered the "long side" of the mesh hole, while the smaller of the two can be considered the "short side" of the mesh hole. It should be noted that if the average gap spacing in the weft direction and the average gap spacing in the warp direction are the same, either one can be considered the "long side" and the other the "short side."

[0087] In this embodiment, the cell ratio (short side / long side) is preferably 0.4 to 0.8, particularly preferably 0.5 to 0.7. When the cell ratio (short side / long side) is within this range, it is easy to achieve both suppression of pinhole formation in the prepreg and improvement of the dimensional stability of the substrate.

[0088] The average area of ​​the pinholes is preferably 15,000 to 45,000 μm 2 More preferably, it is 16000 to 42000 μm 2 , more preferably 1700 to 40000 μm 2, more preferably 18000~39000μm 2 , particularly preferably 20000~37000μm 2 When the average area of ​​the pinholes in the glass cloth is within the above range, it is easy to achieve both suppression of the occurrence of pinholes in the prepreg and improvement of the dimensional stability of the substrate.

[0089] 〔Surface treatment agent (silane coupling agent)〕

[0090] The glass yarn (including glass filaments) constituting the glass cloth is preferably surface-treated with a surface treatment agent such as a silane coupling agent. As the silane coupling agent, for example, a silane coupling agent represented by the following general formula (1) is preferably used.

[0091] X(R) 3-n SiE n …(1)

[0092] {In formula (1), X is an organic functional group having one or more amino groups, an organic functional group having one or more radically reactive unsaturated double bond groups, or an organic functional group having both one or more amino groups and one or more radically reactive unsaturated double bond groups; Y is each independently an alkoxy group; n is an integer from 1 to 3; and R is each independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group}

[0093] X in the general formula (1) can be, for example, an organic functional group having at least one radically reactive unsaturated double bond group such as a carbon-carbon double bond, an organic functional group having at least one amino group, or an organic functional group having both at least one radically reactive unsaturated double bond group and at least one amino group. The amino group can be, for example, a primary amino group, a secondary amino group, a tertiary amino group, or a quaternary ammonium salt. Regarding Y in the general formula (1), any alkoxy group can be used. However, in order to achieve stable treatment of the glass cloth, an alkoxy group having 5 or less carbon atoms is preferred.

[0094] As the surface treatment agent, the silane coupling agent represented by the general formula (1) may be used alone or in combination of two or more silane coupling agents having different Xs in the general formula (1). Examples of the silane coupling agent represented by the general formula (1) include N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropylmethyldimethoxysilane and its hydrochloride, N-β-(N-di(vinylbenzyl)aminoethyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, N-β-(N-di(vinylbenzyl)aminoethyl)-N-γ-(N-vinylbenzyl)-γ-aminopropyltrimethoxysilane and its hydrochloride, silane 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, methacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane and the like, alone or as a mixture thereof.

[0095] [Method for manufacturing glass cloth]

[0096] One aspect of the present embodiment is a method for producing a glass cloth.

[0097] The manufacturing method includes, for example, a process of weaving glass yarns containing a plurality of glass filaments as warp and weft yarns to obtain glass cloth (weaving process). Prior to the weaving process, it is preferred that at least one of the following processes be included: a warping process in which the glass yarns are straightened and flattened, and thereafter coated with a sizing agent; and a process of heating and degreasing the binder component attached to the glass yarns after the warping process and before, during, or after the weaving process (heating and degreasing process). Furthermore, after the heating and degreasing process, it is preferred that at least one of the following processes be included: a process of treating the glass surface with a surface treatment liquid (surface treatment process); and a process of opening the glass yarns after the surface treatment process. By including these processes, the insulation reliability of the glass cloth can be easily improved.

[0098] [Glass yarn warping process]

[0099] The manufacturing method of the present embodiment may include a process of flattening the glass yarn bundle, and a subsequent process of sizing the glass yarn (a process for applying a sizing agent to the glass yarn). Through this treatment, the sizing agent (sizing) can be applied to the glass yarn in a state where the yarn width of the glass yarn is expanded, so it is easy to expand the yarn width in the glass cloth state after weaving. In this case, it is easy to adjust the average gap interval in the weft direction of the obtained glass cloth to within the above range. As a method for flattening the glass yarn bundle, for example, a method of pressurizing the glass yarn with a roller can be cited. From the viewpoint of suppressing the generation of burrs and facilitating the flattening of the yarn bundle, the pressure applied to the glass yarn in this case is preferably 1.0 kg / cm 2 ~6.0kg / cm 2 , more preferably 2.0 kg / cm 2 ~5.0kg / cm 2 , more preferably 2.5kg / cm 2 ~5.5kg / cm 2 .

[0100] 〔Glass cloth weaving process〕

[0101] Glass yarn can be used as warp and weft yarns and woven into the fabric using a loom. This allows for the production of, for example, plain-weave fabrics, namely glass cloth fabrics. To reduce burrs during spinning and warping, the glass yarn used in glass cloth fabrics is preferably surface-treated with a sizing agent primarily composed of starch and polyvinyl alcohol. It should be noted that, in this specification, "glass cloth fabric" refers to glass cloth before it has been heated and deoiled.

[0102] [Process for reducing sizing agent (heating and deoiling process)]

[0103] The sizing agent reduction step can include, for example, a degumming step (heating and deoiling step) in which the glass cloth is heated at a temperature of 300°C to 1600°C. This facilitates the reduction of sizing agent from the glass. It should be noted that the heating and deoiling conditions can be adjusted according to the type of glass and the thickness of the glass cloth. By reducing the amount of thermally oxidized and degraded sizing agent that remains physically attached to the glass surface, the increase in the dielectric loss tangent of the resulting glass cloth can be effectively suppressed.

[0104] The heating time can be selected within the range of, for example, 1 minute to 72 hours, and can be appropriately adjusted depending on the heating temperature, the type of glass, and the like.

[0105] The means for heating the glass cloth blank can be a means of heating the glass cloth blank so that the deoiling temperature is within the range of 300°C to 1600°C, and known heating methods, heating media, heating mechanisms, heating devices and heating components can be used. As heating means, for example, (1) heating the glass cloth blank in a heating furnace, (2) contacting the glass cloth blank with a heating portion, (3) contacting the glass cloth blank with high-temperature steam, etc. By heating the glass cloth blank so that the deoiling temperature is within the range of 300°C to 1600°C, it is easy to efficiently remove organic matter attached to the surface of the glass cloth blank or shorten the time for removing the organic matter. The heating of the glass cloth blank can be carried out sequentially or continuously in a closed system or an open system, or a closed system and an open system can be combined.

[0106] In the case of a closed system, from the perspective of suitable heating by the heating means, it is preferred to place the glass cloth in a heating furnace, and / or, from the perspective of storage space and heating range, it is preferred to heat the glass cloth while storing it in a roll. In addition, from the perspective of easily improving the removal efficiency of organic matter or shortening the removal time of organic matter, it is also preferred to heat the glass cloth while conveying it in a heating furnace.

[0107] In the case of an open system, from the viewpoint of the heated area, it is preferred to heat the glass cloth while conveying it. The glass cloth can be conveyed by, for example, a roll-to-roll method using a roll-out mechanism and a roll-up mechanism.

[0108] [Glass cloth opening process]

[0109] In this process, the glass cloth is subjected to a fiber-opening treatment. By having this process, it is easy to improve the impregnation of the resin in the glass cloth, and further, it is easy to adjust the average gap interval in the weft direction and the warp direction of the obtained glass cloth to the above-mentioned range. Examples of the fiber-opening treatment include a fiber-opening treatment in which water flow pressure is applied to the glass cloth, a fiber-opening treatment based on high-frequency vibration using water (such as degassed water, ion exchange water, deionized water, electrolyzed cationic water or electrolyzed anionic water, etc.) as a medium, and a processing treatment performed by roller-based pressure. The fiber-opening treatment can be performed simultaneously with weaving or after weaving. The fiber-opening treatment can be performed before or after heating deoiling, or simultaneously with heating deoiling. In addition, the fiber-opening treatment can be performed simultaneously with or after the surface treatment process.

[0110] To facilitate adjustment of the average gap spacing in the weft and warp directions of the glass cloth to the aforementioned range, the fiber-spreading step preferably includes the following steps: after the heating and deoiling step and before the surface treatment step, the glass cloth is transported in a liquid while being cleaned and fiber-spread. Furthermore, the conveying speed of the glass cloth during this process is preferably 50 m / min or less. By cleaning and fiber-spreading the glass cloth after the heating and deoiling step and before the surface treatment step, it is easier to remove combustion residues from the heating and deoiling process. In this case, it is easier to prevent adhesion between filaments caused by the combustion residues acting as an adhesive. Furthermore, by performing fiber-spreading before the surface treatment, it is also easier to prevent adhesion between filaments during the surface treatment step. As a result, it is easier to adjust the average gap spacing in the weft and warp directions of the glass cloth and also improve insulation reliability.

[0111] The cleaning and fiber-opening step of the glass cloth preferably includes irradiating the glass cloth in a liquid after the heat deoiling step and before the surface treatment step with ultrasonic waves, thereby cleaning mainly the combustion residues from the heat deoiling from the glass cloth and fiber-opening the glass (ultrasonic cleaning). The cleaning and fiber-opening step preferably includes transporting the glass cloth in a roll-to-roll manner in a liquid irradiated with ultrasonic waves using an ultrasonic oscillator and treating the glass cloth.

[0112] As the liquid used in ultrasonic cleaning, water or organic solvent can be used. From the viewpoint of safety and protection of the global environment, it is preferred to use the liquid with water as the main component. In order to improve cleaning efficiency, the liquid used in cleaning can also be added with a surfactant and a pH adjusting agent.

[0113] The temperature of the liquid used for ultrasonic cleaning is not particularly limited, but is preferably 5° C. or higher from the viewpoint of improving the cleaning effect. Furthermore, from the viewpoint of safety, the temperature of the liquid used for cleaning is preferably 60° C. or lower.

[0114] By running the glass cloth in a liquid irradiated with ultrasonic waves by an ultrasonic oscillator, the glass cloth can be irradiated with ultrasonic waves in the liquid and cleaned. The line tension acting on the warp yarn in the cleaning step is preferably 30 to 500 N / m.

[0115] Ultrasonic cleaning can be performed using ultrasonic waves with a frequency of 20 to 200 kHz. The frequency of the ultrasonic waves is preferably 20 to 50 kHz, and more preferably 20 to 30 kHz. Using ultrasonic waves with a frequency of 20 to 200 kHz makes it easier to prevent significant defects such as mesh warping on the glass cloth and facilitates cleaning.

[0116] Ultrasonic cleaning can preferably use an output power of 0.07 to 3.60 W / cm 2The more preferred range of ultrasonic output power is 0.14 to 2.16 W / cm 2 The further preferred range is 0.21 to 1.44 W / cm 2 If the ultrasonic output power is 0.07W / cm 2 If the ultrasonic output power is 3.60W / cm 2 The following makes it easy to prevent obvious defects such as mesh bending and easy to perform uniform cleaning.

[0117] The conveying speed of the glass cloth during ultrasonic cleaning is preferably 50 m / min or less, more preferably 40 m / min or less, and even more preferably 30 m / min or less. A conveying speed of 50 m / min or less facilitates good cleaning and fiber opening of the glass cloth or its intermediate. Furthermore, the generation of burrs and mesh deviation caused by damage during conveyance is easily suppressed.

[0118] The liquid used for ultrasonic cleaning usually contains air with nitrogen and oxygen as main components, and the dissolved oxygen amount (mass ratio) is preferably 1 to 20 ppm, more preferably in the range of 3 to 17 ppm, and further preferably in the range of 4 to 14 ppm. By managing the dissolved oxygen amount, it is easy to indirectly control the dissolved gas amount. In this case, it is easy to control the degree of attenuation of the ultrasonic wave due to the dissolved gas. If the dissolved oxygen amount is 1 ppm or more, it is easy to implement a uniform fiber opening process. If the dissolved oxygen amount is 20 ppm or less, it is easy to apply a good cleaning effect to the fiber fabric. That is, when the dissolved oxygen amount is 1 to 20 ppm, it is easy to obtain a uniform and good fiber opening effect.

[0119] 〔Surface treatment process of glass cloth〕

[0120] Glass cloth surface treatment methods include, for example, a method comprising: a coating step in which the surface of the glass filaments is coated with the silane coupling agent using a treatment liquid containing the silane coupling agent; and a fixing step in which the silane coupling agent is fixed to the surface of the glass filaments by heat drying. The treatment liquid preferably contains 0.1% to 3.0% by mass of the silane coupling agent. Preferably, the coating step substantially completely covers the surface of the glass filaments with the silane coupling agent.

[0121] The method for applying the treatment liquid to the glass cloth includes: (1) a method in which the treatment liquid is accumulated in a bath and the glass cloth is immersed in and passed through the bath (hereinafter referred to as the "immersion method"); (2) a method in which the treatment liquid is directly applied to the glass cloth using a roll coater, die coater, or gravure coater. When applying the treatment liquid by the immersion method (1), 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.

[0122] To ensure sufficient reaction between the silane coupling agent and the glass, the heating and drying temperature is preferably 90°C or higher, more preferably 100°C or higher. To prevent degradation of the organic functional groups of the silane coupling agent, the heating and drying temperature is preferably 300°C or lower, more preferably 200°C or lower.

[0123] The surface treatment method of glass cloth may include: a step of cleaning at least a portion of the silane coupling agent fixed to the surface of the glass filaments with a cleaning liquid such as water; and a step of adjusting the amount of silane coupling agent attached (adjustment step). Cleaning can be performed using a high-pressure water spray or the like.

[0124] As a solvent for dissolving or dispersing the silane coupling agent, either water or an organic solvent can be used. From the perspectives of safety and environmental protection, water is preferably used as the main solvent. As a method for obtaining a treatment liquid with water as the main solvent, it is preferred to directly add the silane coupling agent to water or to dissolve the silane coupling agent in a water-soluble organic solvent to form an organic solvent solution, and then add the organic solvent solution to water. To improve the water dispersibility or stability of the silane coupling agent in the treatment liquid, a surfactant may also be used in combination.

[0125] 〔Fiber opening process after surface treatment〕

[0126] In the fiber-opening process of the glass filaments after the surface treatment, methods such as spraying water (high-pressure water fiber-opening), an oscillating washing machine, ultrasonic water, or a mangle can be used to open the glass cloth. During this fiber-opening process, the tension applied to the glass cloth is reduced, which tends to further increase the yarn width. It should be noted that to prevent burrs on the glass cloth caused by fiber-opening, it is preferable to implement measures such as reducing friction with contacting components during weaving of the glass yarn, optimizing the surface treatment agent, and increasing the adhesion level.

[0127] 〔About Each Process〕

[0128] The steps described above do not necessarily need to be performed in separate processes; multiple steps can be combined into a single process. The composition of the glass cloth often remains unchanged before and after fiber opening. Furthermore, the glass cloth manufacturing method may include any other steps besides the above steps. For example, after the fiber opening step, a slit process for cutting the cloth to a predetermined width may be included. Furthermore, the order of the steps described above may be reversed if possible.

[0129] The above-described method for producing glass cloth makes it easy to adjust the average gap spacing in the weft and warp directions to the above-described ranges, thereby achieving a glass cloth that can achieve both suppression of pinhole formation in the prepreg and improvement of the dimensional stability of the substrate. The glass cloth of this embodiment can be used, for example, as a material for producing printed circuit boards.

[0130] 〔Prepreg〕

[0131] Another embodiment of the present invention is a prepreg comprising the above-mentioned glass cloth and a thermosetting resin. In order to manufacture the prepreg, the manufacture may be based on a prescribed method. For example, a base resin such as an epoxy resin is diluted with an organic solvent to prepare a thermosetting resin varnish (also referred to as "varnish" in this specification), and after the above-mentioned glass cloth is impregnated therein, the organic solvent is volatilized in a drying furnace, and the thermosetting resin is cured to the B stage (semi-cured state). It should be noted that the amount of thermosetting resin attached to the glass cloth is preferably adjusted in such a way that the mass of the varnish solid content is 20 to 80% by mass relative to the total mass of the varnish solid content and the glass cloth.

[0132] Examples of base resins used in prepregs include thermosetting resins such as epoxy resins, unsaturated polyester resins, polyimide resins, bismaleimide triazine (BT) resins, and cyanate resins; thermoplastic resins such as polyphenylene ether (PPO) resins, polyetherimide resins, and fluororesins; and mixed resins thereof. Furthermore, resins mixed with inorganic fillers such as aluminum hydroxide, talc, and silica fillers can be used.

[0133] [Printed Circuit Board]

[0134] Another aspect of this embodiment is a printed circuit board comprising the above-mentioned prepreg. The printed circuit board comprises one or more of the above-mentioned prepregs. Specifically, the printed circuit board comprises the above-mentioned glass cloth and a cured product of the base resin composition impregnated into the glass cloth. The printed circuit board of this embodiment exhibits high adhesion to resin and excellent dielectric properties.

[0135] [Integrated Circuits and Electronic Devices]

[0136] Another embodiment of the present invention provides an integrated circuit and an electronic device including the printed wiring board described above. The integrated circuit and the electronic device obtained using the printed wiring board of the present embodiment each have excellent various characteristics.

[0137] Example

[0138] The following are examples and comparative examples for illustrating the present embodiment. However, the present embodiment is not limited to the following examples. With respect to the examples and comparative examples, unless otherwise specified, various production, measurements, and evaluations were performed at room temperature (25° C.) and atmospheric pressure.

[0139] [Measurement and evaluation]

[0140] [physical properties]

[0141] [TEX value, number of filaments, weaving density and thickness]

[0142] The physical properties of the glass yarn and glass cloth, specifically, the TEX value, the number of filaments, the weaving density of warp and weft yarns (weaving density), and the thickness of the glass cloth were measured in accordance with JIS R3420.

[0143] 〔Average filament diameter of glass yarn〕

[0144] A cross section of 30 glass yarn bundles at arbitrary positions in the glass yarn was obtained and observed using a scanning electron microscope. The average filament diameter was calculated from the observed image to determine the average filament diameter (μm) of the glass yarn.

[0145] 〔Average number of filaments in glass yarn〕

[0146] The average number of filaments (number of filaments) was determined by calculating the average value from the number of filaments measured in accordance with JIS R3420.

[0147] 〔Wave and weft yarn width〕

[0148] Using a camera with a field of view of approximately 2.3 × 1.7 mm and a resolution of 2.26 μm / pixel, the glass cloth was imaged and scanned at 1 mm intervals along the MD or TD direction. Based on the obtained data, the average yarn width (μm) was calculated for each of the warp and weft yarns of the glass cloth. The average yarn width (μm) was calculated using the yarn widths of at least 100 glass yarns.

[0149] 〔Glass cloth fineness〕

[0150] For the warp and weft yarns of glass cloth, use the following formula to calculate their fineness (%):

[0151] Warp yarn fineness [%] = {warp yarn width [μm] / (number of warp filaments [pieces] × warp filament diameter [μm])} × 100

[0152] The open fineness of the weft yarn [%]={the yarn width of the weft yarn [μm] / (the number of filaments of the weft yarn [pieces]×the filament diameter of the weft yarn [μm])}×100.

[0153] Then, the average value of the openness of each of the warp yarn and the weft yarn was calculated, thereby determining the average openness (%) of the glass cloth.

[0154] [Average gap between the warp and weft directions of glass cloth]

[0155] The following formula is used to calculate the average gap spacing in the warp and weft directions of the glass cloth:

[0156] Average gap distance in the warp direction (gap distance between adjacent weft yarns) [μm] = {25000 - (weft yarn width [μm] × weft yarn weaving density [pieces / 25mm])} / (weft yarn weaving density [pieces / 25mm] - 1)

[0157] Average gap distance in the weft direction (gap distance between adjacent warp yarns) [μm] = {(25000-warp yarn width [μm]×warp yarn weaving density [pieces / 25mm])} / (warp yarn weaving density [pieces / 25mm]-1).

[0158] [Average area of ​​holes and ratio of holes (short side / long side)]

[0159] Use the following formula to calculate the average area of ​​the holes in the glass cloth:

[0160] The average area of ​​the holes [μm 2 ] = average gap spacing in the warp direction [μm] × average gap spacing in the weft direction [μm].

[0161] Compare the average gap spacing [μm] in the warp direction with the average gap spacing [μm] in the weft direction, and regard the longer one (the average gap spacing in the warp direction in this embodiment) as the long side, and the shorter one (the average gap spacing in the weft direction in this embodiment) as the short side.

[0162] And, the ratio of the holes (short side / long side) is calculated using the following formula:

[0163] The ratio of the holes (short side / long side) = average gap spacing in the weft direction [μm] / average gap spacing in the warp direction [μm].

[0164] 〔Dielectric constant and dielectric loss tangent〕

[0165] In accordance with IEC 62562, the dielectric constant and dielectric loss tangent were measured for each glass. Specifically, glass plate samples were obtained whose dimensions were adjusted to those required for the measurement in the separation column resonator. The sample was stored in a constant temperature and humidity oven at 23°C and 50% RH for more than 8 hours and humidified. Thereafter, the dielectric properties at 10 GHz were measured using a separation column resonator (manufactured by EM LABO) and an impedance analyzer (manufactured by Agilent Technologies). Each sample was measured 5 times, and the average value was obtained.

[0166] Bulk dielectric constant and bulk dielectric loss tangent

[0167] A glass plate of the same type and composition as the glass cloths for which the dielectric loss tangent was measured and having a thickness of 300 μm was prepared. Using the thickness obtained from the glass plate measurement, the bulk dielectric constant and bulk dielectric loss tangent at 10 GHz were measured using the same method as the dielectric loss tangent measurement described above.

[0168] In the table, the overall dielectric constant is shown in the item "Dk@10 GHz", and the overall dielectric loss tangent is shown in the item "Df@10 GHz".

[0169] Coefficient of Thermal Expansion (CTE) of Glass

[0170] The measurement was conducted in accordance with JIS R3102-1995. Specifically, a block of glass was processed into a 4 mm × 4 mm × 20 mm test piece using a diamond cutter and grinder to produce a CTE test piece. The resulting test piece was heated at a temperature increase rate of 5°C / minute, and the elongation at temperatures ranging from 50°C to 200°C was measured. The thermal expansion coefficient of the glass was determined based on the elongation obtained.

[0171] [Example 1]

[0172] [Production of glass cloth]

[0173] Warp warping was performed using glass A listed in the table below as the glass type, and using glass yarn having an average filament diameter of 3.6 μm, 38 filaments, and a twist of 1.0 Z. The glass yarn was flattened by applying pressure (pressing) to the warp yarn aligned at a specified conveying speed using a roller with a specified load.

[0174] Here, the warping conditions of the warp yarns are as follows.

[0175] (Warping conditions of warp yarn)

[0176] Warp conveying speed: 60m / min

[0177] Rolling load: 3.0kg / cm 2

[0178] Thereafter, a sizing agent containing polyvinyl alcohol (PVA) resin as the main component is attached to the glass yarn according to the following steps. That is, a 5% by mass aqueous solution of PVA (trade name: PVA403, manufactured by Kuraray Co., Ltd.) is prepared, and 2% by mass of hydrogenated castor oil as a lubricant is mixed into the aqueous solution to obtain the sizing agent. The sizing agent, which is kept warm at 60°C, is attached to the glass yarn and then dried to perform the sizing treatment. Thereafter, a glass cloth is woven using an air jet loom with a weaving density of 75 warp yarns / mm and 100 weft yarns / mm. At this time, the weaving is performed in such a way that the cloth width becomes 1300 mm. It should be noted that the same glass yarn as the warp yarn is used as the weft yarn.

[0179] The obtained glass cloth was heated at 360°C for 72 hours in a rolled state to remove the sizing agent attached to the glass surface (heat degreasing process). Then, the glass cloth was moved in water at a conveying tension of 150N and a line speed of 30m / min while being irradiated at a frequency of 25GHz and an output power of 0.72W / cm 2 Ultrasonic waves are used to clean the residue (cleaning and fiber opening process).

[0180] Next, a treatment solution was prepared by dispersing 1.0% by mass of N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (Z6032, manufactured by Dow Corning Toray Co., Ltd.) in pure water adjusted to pH 3 using acetic acid. The silane coupling agent was fixed by immersing the cloth in the treatment solution, squeezing the solution, and then heating and drying at 130°C for 60 seconds. The cloth was then sprayed at 2.0 kg / cm 2 The cloth was subjected to high-pressure opening at a pressure of 1000 nm (opening step after surface treatment), and then dried at 130° C. for 1 minute, thereby obtaining a glass cloth.

[0181] [Prepreg production]

[0182] Epoxy resin varnish was prepared by mixing 80 parts by mass of low-brominated bisphenol A epoxy resin, 20 parts by mass of cresol novolac epoxy resin, 2 parts by mass of dicyandiamide, 0.2 parts by mass of 2-ethyl-4-methylimidazole, and 100 parts by mass of 2-methoxyethanol. A glass cloth was then impregnated with the epoxy resin varnish while being conveyed at a speed of 3 m / min. Excess varnish was scraped off the glass cloth by passing it through a slit with a clearance adjusted to achieve an epoxy resin varnish content of 68% by mass. The varnish was then dried at a temperature of 170°C for 1 minute and 30 seconds. This produced a prepreg.

[0183] [Ratio of the resin layers on the front and back of the prepreg]

[0184] The resulting prepreg is embedded in a resin (EpoMount base, curing agent II, manufactured by REFINETEC). A cross-section of the prepreg, along with the resin, is cut and polished to achieve a roundness of 0.9 or greater for the glass filaments. This cross-section is observed using an optical microscope at a magnification (e.g., 1000x), yielding an image containing the glass cloth layer and the resin layer on top of it. From this image, the thickness of the resin layer on both the front and back sides of the prepreg is determined. The resin layer ratio is calculated by dividing the lower of the obtained values ​​by the higher value.

[0185] In this case, within the observation area, the area up to the glass filaments closest to the resin layer is defined as the "glass cloth layer," and the area closer to the resin layer is defined as the "resin layer." The resin layer thickness is then determined for both the front and back sides. This operation is repeated 30 times, varying the measurement position on the front and back sides. The average of the obtained values ​​is then used to calculate the ratio of the front to back resin layers of the prepreg.

[0186] [Prepreg yield rate (pinhole suppression rate)]

[0187] Samples measuring 400 mm x 400 mm were obtained from the resulting prepreg. A total of 150 samples of these dimensions were obtained, and the number of pinholes in each sample was counted by visual inspection. Prepregs with four or fewer pinholes were considered good, and the yield (%) of the 150 samples was evaluated.

[0188] [Evaluation method for dimensional stability of substrates]

[0189] A 1ply substrate for dimensional stability evaluation was obtained by placing 12 μm copper foil on both sides of a 340 mm long and 340 mm wide prepreg obtained by the above prepreg production method and heating and pressing at 175°C and 3.9 MPa for 1 hour.

[0190] The resulting substrate was marked at 9 locations (3 in the warp direction x 3 in the weft direction) at 125 mm intervals. The intervals between two adjacent marks were measured at 6 locations in both the warp and weft directions (measurement value a). The copper foil was then removed by etching, and the substrate was heated at 170°C for 30 minutes. The intervals between the marks were then measured again (measurement value b). The dimensional change rate was calculated using the following formula.

[0191] Dimensional change rate (%) = ratio (%) of {(difference between measured value a and measured value b) / measured value a}.

[0192] Then, the absolute value obtained by subtracting the minimum value from the maximum value of the six dimensional change rates in each of the warp and weft directions was calculated, and the resulting value was used as the "variation in dimensional change rate."

[0193] [Example 2] to [Example 3]

[0194] A glass cloth was obtained by the same method as in Example 1 except that the items described in the following table, such as the weaving density of the warp and weft yarns in the glass yarn and glass cloth, were changed as shown in the following table.

[0195] [Example 4]

[0196] Glass cloth was obtained by the same method as in Example 1 except that the items listed in the table below, such as the weaving density of the warp and weft yarns in the glass yarn and glass cloth, and the warping conditions during warping were changed as follows.

[0197] (Warping conditions of warp yarn)

[0198] Warp conveying speed: 60m / min

[0199] Rolling load: 4.0kg / cm 2

[0200] [Example 5]

[0201] A glass cloth was obtained by the same method as in Example 1 except that the items described in the following table, such as the weaving density of the warp and weft yarns in the glass yarn and glass cloth, were changed as shown in the following table.

[0202] [Example 6]

[0203] Glass cloth was obtained by the same method as in Example 1 except that the items listed in the table below, such as the weaving density of the warp and weft yarns in the glass yarn and glass cloth, and the warping conditions during warping were changed as follows.

[0204] (Warping conditions of warp yarn)

[0205] Warp conveying speed: 30m / min

[0206] Rolling load: 4.2kg / cm 2

[0207] [Example 7]

[0208] Glass cloth was obtained by the same method as in Example 1 except that the items listed in the table below, such as the weaving density of the warp and weft yarns in the glass yarn and glass cloth, and the warping conditions during warping were changed as follows.

[0209] (Warping conditions of warp yarn)

[0210] Warp conveying speed: 20m / min

[0211] Rolling load: 4.6kg / cm 2

[0212] [Example 8]

[0213] Glass cloth was obtained by the same method as in Example 1 except that the items listed in the table below, such as the weaving density of the warp and weft yarns in the glass yarn and glass cloth, and the warping conditions during warping were changed as follows.

[0214] (Warping conditions of warp yarn)

[0215] Warp conveying speed: 40m / min

[0216] Rolling load: 3.0kg / cm 2

[0217] [Comparative Example 1]

[0218] Warp warping was performed using glass A (listed in the table below) as the glass type, glass yarn with an average filament diameter of 3.6 μm, 38 filaments, and a twist of 1.0Z. A sizing agent composed primarily of polyvinyl alcohol (PVA) resin was applied to the warp yarns, which were aligned at a conveying speed of 60 m / min, according to the following procedure. Specifically, a 5% by mass aqueous solution of PVA (trade name: PVA403, manufactured by Kuraray Co., Ltd.) was prepared, and 2% by mass of hydrogenated castor oil was added to the aqueous solution as a lubricant to obtain the sizing agent. The sizing agent was applied to the glass yarns while being kept at 60°C and then dried to complete the sizing treatment. Subsequently, a glass cloth was woven using an air-jet loom with a weave density of 103 warp yarns / mm and 108 weft yarns / mm. The weaving was performed to a cloth width of 1300 mm. In addition, as a weft yarn, the same glass yarn as the warp yarn was used.

[0219] The obtained glass cloth was heated at 360° C. for 72 hours in a rolled state to remove the sizing agent adhering to the glass surface (heat deoiling step).

[0220] Next, a treatment solution was prepared by dispersing 1.0% by mass of N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (Z6032, manufactured by Dow Corning Toray Co., Ltd.) in pure water adjusted to pH 3 with acetic acid. The cloth was immersed in the treatment solution, squeezed, and then heated and dried at 130°C for 60 seconds to fix the silane coupling agent. The cloth was then sprayed at 2.0 kg / cm 2 The cloth was subjected to high-pressure opening at a pressure of 1000 nm (opening step after surface treatment), and then dried at 130° C. for 1 minute, thereby obtaining a glass cloth.

[0221] [Comparative Example 2]

[0222] Warp warping was performed using glass A, as shown in the table below, and glass yarn with an average filament diameter of 4.0 μm, 34 filaments, and a twist of 1.0Z. A sizing agent composed primarily of polyvinyl alcohol (PVA) resin was applied to the warp yarns, which were aligned at a conveying speed of 60 m / min, according to the following procedure. Specifically, a 5% by mass aqueous solution of PVA (trade name: PVA403, manufactured by Kuraray Co., Ltd.) was prepared, and 2% by mass of hydrogenated castor oil was added to the aqueous solution as a lubricant to obtain the sizing agent. The sizing agent was applied to the glass yarns while being kept at 60°C and then dried to complete the sizing treatment. Subsequently, a glass cloth was woven using an air-jet loom with a weaving density of 105 warp yarns / mm and 105 weft yarns / mm. The weaving was performed to a cloth width of 1300 mm. In addition, as a weft yarn, the same glass yarn as the warp yarn was used.

[0223] The obtained glass cloth was heated at 400° C. for 40 hours in a rolled state to remove the sizing agent adhering to the glass surface (heat deoiling step).

[0224] Next, a treatment solution was prepared by dispersing 1.0% by mass of N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride (Z6032, manufactured by Dow Corning Toray Co., Ltd.) in pure water adjusted to pH 3 with acetic acid. The cloth was immersed in the treatment solution, squeezed, and then heated and dried at 130°C for 60 seconds to fix the silane coupling agent. Next, the cloth was sprayed at 10 kg / cm 2 The cloth was subjected to high-pressure opening at a pressure of 1000 nm (opening step after surface treatment), and then dried at 130° C. for 1 minute, thereby obtaining a glass cloth.

[0225] [Comparative Example 3]

[0226] A glass cloth was obtained by the same method as in Example 1 except that the glass yarn was not flattened by rollers during warping and the cleaning and opening steps were not performed.

[0227] [Comparative Example 4]

[0228] A glass cloth was obtained by the same method as in Comparative Example 3 except that high-pressure fiber opening after the surface treatment (fiber opening step after the surface treatment) was not performed.

[0229] [Comparative Example 5]

[0230] A glass cloth was obtained by the same method as in Example 1 except that the items described in the following table, such as the weaving density of the warp and weft yarns in the glass yarn and glass cloth, were changed as shown in the following table.

[0231] [Comparative Example 6]

[0232] The glass cloth was obtained by the same method as in Example 1 except that the items listed in the table below, such as the weaving density of the warp and weft yarns in the glass yarn and glass cloth, were changed as shown in the table below. During the warp warping, the glass yarn was not flattened by rollers and the cleaning and fiber-opening process was not performed.

[0233] The results of the measurements and evaluations are shown in the table below.

[0234] In the table, the yield rate of the prepreg (the rate at which pinholes are suppressed) can be determined by the "yield rate" item, while the dimensional stability of the substrate can be determined by the "variation in dimensional change rate" item. Here, using a prepreg with excellent dimensional stability facilitates the production of a substrate with excellent dimensional stability. Therefore, if the "variation in dimensional change rate" result for the substrate is good, it is presumed that the prepreg used as the raw material also has excellent dimensional stability.

[0235] [Table 1]

[0236] Table 1

[0237]

[0238] [Table 2]

[0239]

[0240] [Table 3]

[0241]

[0242] The results in the above table confirmed that according to the Examples, it was possible to provide a glass cloth capable of realizing a prepreg and a printed wiring board having excellent dimensional stability and suppressing the occurrence of pinholes in the prepreg.

[0243] In particular, it was confirmed that according to the Examples, both the "variation in the dimensional change rate in the warp direction (warp yarn direction)" and the "variation in the dimensional change rate in the weft direction (weft yarn direction)" were equal to or less than the specified values.

[0244] Industrial applicability

[0245] The present invention can be suitably utilized in related fields such as glass cloth, prepreg, and printed circuit boards.

Claims

1. A glass cloth comprising glass yarns as warp yarns and weft yarns, The weaving density of the warp yarn and the weft yarn is 50 to 110 yarns / 25 mm. The thickness of the glass cloth is less than 20 μm, The average gap intervals in the weft direction and the warp direction forming the mesh holes are 162 to 240 μm and 65 to 200 μm respectively.

2. The glass cloth according to claim 1, wherein The TEX value of the glass yarn is 0.2 to 2.0 g / 1000 m.

3. The glass cloth according to claim 1 or 2, wherein The average area of ​​the mesh holes is 15000 to 45000 μm 2 .

4. The glass cloth according to claim 1 or 2, having an area of ​​15000 to 45000 μm 2 The hole in the network.

5. The glass cloth according to claim 1 or 2, wherein The glass yarn comprises a plurality of glass filaments, The diameter of the glass filaments in the glass yarn is 2.0 to 4.5 μm, and the number of the glass filaments is 10 to 50.

6. The glass cloth according to claim 1 or 2, wherein The ratio of the mesh holes (short side / long side) is 0.4 to 0.

8.

7. The glass cloth according to claim 1 or 2, wherein The average fineness of the warp yarn is 70-110%, and / or the average fineness of the weft yarn is 90-140%.

8. The glass cloth according to claim 1 or 2, wherein The ratio of the glass yarn (weaving density of warp yarns / weaving density of weft yarns) is less than 1.

0.

9. The glass cloth according to claim 1 or 2, wherein The glass yarn is surface-treated with a silane coupling agent.

10. The glass cloth according to claim 9, wherein The silane coupling agent comprises a silane coupling agent represented by the following general formula (1): X(R) 3-n Yes n …(1) In formula (1), X is an organic functional group having one or more amino groups, an organic functional group having one or more unsaturated double bond groups having free radical reactivity, or an organic functional group having both one or more amino groups and one or more unsaturated double bond groups having free radical reactivity; Each Y is independently an alkoxy group; n is an integer of 1 to 3; and each R is independently a group selected from the group consisting of a methyl group, an ethyl group, and a phenyl group.

11. A prepreg comprising the glass cloth according to claim 1 or 2 and a thermosetting resin.

12. A printed circuit board comprising the prepreg according to claim 11.

13. An integrated circuit comprising the printed circuit board according to claim 12.

14. An electronic device comprising the printed circuit board according to claim 12.

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