Glass cloth, surface-treated glass cloth, prepreg, and printed circuit board

Abstract

A fiberglass cloth possessing both good fiber opening degree and good fiber opening uniformity, and a surface-treated fiberglass cloth, a prepreg, and a printed circuit board made using the fiberglass cloth. The fiberglass cloth is woven from multiple warp yarns and multiple weft yarns, all of which are fiberglass yarns. The average fiber opening coefficient SD per unit area of ​​the fiberglass cloth is 0.35 to 0.75, the average uniformity coefficient RA per unit area is 0.10 to 0.40, and the RA / SD value is 0.10 to 1.10. The definitions of SD and RA are as follows: SD = ; RA = , W is the average width of the warp yarns, F is the average width of the weft yarns, D... w The average weave density of the warp yarns, D f R is the average weave density of the weft yarn. w The total width of the warp yarns, and R f The width of the weft yarn is the full distance.

Description

Technical Field

[0001] This invention relates to a fiber cloth, and more particularly to a glass fiber cloth and its applications. Background Technology

[0002] With the rapid development of technology, electronic products are being researched and developed to meet demands for multifunctionality, high-speed transmission, and thinness and miniaturization. This has spurred efforts to reduce the thickness of fiberglass cloth (hereinafter referred to as fiberglass cloth) used in the manufacture of printed circuit boards (PCBs). To reduce the thickness of fiberglass cloth, fiberglass yarns with smaller average monofilament diameters are used as warp and weft yarns. However, this results in a higher proportion of the area occupied by the "screen area" (i.e., the gaps between the warp and weft yarns in the fiberglass cloth). When the screen area is too high, the fiber weave effect is more likely to occur when signals pass through the PCB made with this type of fiberglass cloth, adversely affecting the signal transmission rate.

[0003] To address the aforementioned problems, a common strategy is to increase the degree of fiber opening (also known as fiber splitting) of the fiberglass cloth. Fiber opening refers to loosening and evenly spreading the multiple monofilaments constituting the fiberglass yarn into a flat shape to increase the surface area of ​​the fiberglass yarn, thereby reducing the size of the screen window made of the fiberglass cloth. For example, Taiwan Patent Publication No. I720996 and Taiwan Patent Publication No. I723117 both disclose a fiberglass cloth with a specific degree of fiber opening. Summary of the Invention

[0004] However, the inventors discovered that if the fiberglass cloth only meets the declared fiber opening degree but its fiber opening uniformity is poor, that is, the size difference of each screen in the fiberglass cloth is too large, the prepreg made using the fiberglass cloth will have microvoids. During the manufacturing process of printed circuit boards, the prepreg will have excessive expansion and contraction variations, resulting in the printed circuit board being bent or warped, thus leading to poor yield of the printed circuit board.

[0005] Therefore, the first objective of this invention is to provide a fiberglass cloth that has both good fiber opening degree and good fiber opening uniformity.

[0006] The fiberglass cloth of the present invention is woven from multiple warp yarns and multiple weft yarns of fiberglass yarn. The average unit area opening coefficient SD of the fiberglass cloth is between 0.35 and 0.75, the average unit area uniformity coefficient RA is between 0.10 and 0.40, and the RA / SD value is between 0.10 and 1.10. The definitions of SD and RA are as follows:

[0007] SD = and RA = ;

[0008] W is the average width of the warp yarns, in μm; F is the average width of the weft yarns, in μm; D w The average weave density of the warp yarns is expressed in yarns per 25.4 mm; D f R represents the average weft yarn weave density, expressed in yarns per 25.4 mm. w The width of the warp yarn is the total distance, in μm; and R f The width of the weft yarn is the total distance, in μm.

[0009] The fiberglass cloth of the present invention has an RA / SD value between 0.20 and 1.00.

[0010] The fiberglass cloth of the present invention has an RA / SD value between 0.20 and 0.90.

[0011] The fiberglass cloth of the present invention comprises each warp and each weft yarn consisting of multiple monofilaments. The average diameter of the monofilament in each warp yarn ranges from 3.0 μm to 5.0 μm and the average number of monofilaments ranges from 30 to 200. The average diameter of the monofilament in each weft yarn ranges from 3.0 μm to 5.0 μm and the average number of monofilaments ranges from 30 to 200.

[0012] The fiberglass cloth of this invention has an average thickness ranging from 10.0 μm to 50.0 μm and an average basis weight ranging from 10.0 g / m³. 2 Up to 50.0g / m 2 Based on the average area of ​​the fiberglass cloth, the average weaving density of the warp yarns ranges from 50 yarns / 25.4mm to 100 yarns / 25.4mm, and the average weft yarns range from 50 yarns / 25.4mm to 100 yarns / 25.4mm.

[0013] A second objective of this invention is to provide a surface-treated fiberglass cloth.

[0014] The surface-treated fiberglass cloth of the present invention is obtained by surface treatment of the fiberglass cloth as described above. The surface treatment includes reacting the fiberglass cloth with a treatment liquid to change the properties of the fiberglass cloth. The treatment liquid is prepared using a treatment agent selected from aminosilane coupling agents, alkenylsilane coupling agents, acryloyloxysilane coupling agents, or any combination thereof.

[0015] A third objective of the present invention is to provide a prepreg.

[0016] The prepreg of the present invention is formed by partially curing an impregnated fabric comprising resin and surface-treated fiberglass cloth as described above.

[0017] The prepreg of the present invention uses a thermosetting resin.

[0018] The thermosetting resin of the prepreg described in this invention is selected from epoxy resin, polyphenylene ether resin, or bismaleimide-triazine resin.

[0019] The fourth objective of this invention is to provide a printed circuit board.

[0020] The printed circuit board of the present invention is made using a prepreg comprising the material described above.

[0021] The beneficial effects of this invention are as follows: The inventors comprehensively considered the average width, average weaving density, and width span of the warp and weft yarns to design the SD and RA, and limited the SD to between 0.35 and 0.75, the RA to between 0.10 and 0.40, and the RA / SD value to between 0.10 and 1.10. This allows the fiberglass cloth of this invention to have both good fiber opening degree and good fiber opening uniformity. Consequently, the surface-treated fiberglass cloth of this invention made using the fiberglass cloth also has the advantages of good fiber opening degree and good fiber opening uniformity. As a result, the prepreg of this invention made using the surface-treated fiberglass cloth has a good appearance and is free of glue holes. Consequently, the printed circuit board of this invention made using the prepreg not only has a high yield but also has the advantage of fast signal transmission. Attached Figure Description

[0022] Figure 1 This is a partial schematic diagram of the fiberglass cloth of the present invention. A represents the area where each warp yarn overlaps with each weft yarn, B represents the area of ​​each warp yarn that does not overlap with each weft yarn, C represents the area of ​​each weft yarn that does not overlap with each warp yarn, and D represents the area of ​​each screen window. Detailed Implementation

[0023] This invention provides a fiberglass cloth, a surface-treated fiberglass cloth made using the fiberglass cloth, a prepreg made using the surface-treated fiberglass cloth, and a printed circuit board made using the prepreg. The invention will now be described in detail.

[0024] <Fiberglass cloth>

[0025] The fiberglass cloth of the present invention is woven from multiple warp yarns and multiple weft yarns of fiberglass yarn. The average unit area opening coefficient SD of the fiberglass cloth is between 0.35 and 0.75, the average unit area uniformity coefficient RA is between 0.10 and 0.40, and the RA / SD value is between 0.10 and 1.10.

[0026] The definitions of SD and RA are as follows:

[0027] SD = ;

[0028] RA = ;

[0029] W represents the average width of the warp yarns, in μm.

[0030] F represents the average width of the weft yarn, in μm.

[0031] D w The average weave density of the warp yarns is expressed in yarns per 25.4 mm.

[0032] D f The average weft yarn weave density is expressed in yarns per 25.4 mm.

[0033] R w The warp width is the total width of the warp yarn, which is the difference between the maximum and minimum width of the warp yarn, in μm; and

[0034] R f The width of the weft yarn is the total width, which is the difference between the maximum and minimum width of the weft yarn, in μm.

[0035] The average fiber opening coefficient SD per unit area represents the "degree of fiber opening" of the fiberglass cloth. This represents the average area of ​​overlap between the warp and weft yarns. 25400 is a unit derived from weave density (yarns / 25.4mm = yarns / 25400μm), representing the maximum width that can be allocated to each warp and weft yarn. This refers to the maximum area that each warp and weft yarn can be allocated, including the area of ​​overlap between each warp and weft yarn (see [reference]). Figure 1 Area A), the area of ​​each warp yarn that does not overlap with each weft yarn (see Figure 1 (Area B), the area of ​​each weft yarn that does not overlap with each warp yarn (see section B). Figure 1 (Carea C), and the area of ​​each screen window (see...) Figure 1 (Area D).

[0036] The average unit area uniformity coefficient RA represents the "fiber opening uniformity" of the fiberglass cloth. This represents the total span factor of the warp yarn (i.e., the ratio of the total width span of the warp yarn to its average width). This represents the total span factor of the weft yarn (i.e., the ratio of the total width span of the weft yarn to its average width), so... It refers to the geometric mean of the total distance coefficients of the warp and weft yarns, showing the distribution of the warp and weft yarns in the fiberglass cloth, that is, the degree of size difference of the warp and weft yarns in the fiberglass cloth, corresponding to the degree of size difference of each screen window in the fiberglass cloth.

[0037] By controlling the SD and RA values, and ensuring that the RA / SD values ​​are within the aforementioned range, the fiberglass cloth can achieve both good fiber opening degree and good fiber opening uniformity. This means that the area ratio of the screens in the fiberglass cloth is low, and the size difference between the screens in the fiberglass cloth is small. Consequently, the surface-treated fiberglass cloth made using the fiberglass cloth also has the advantages of good fiber opening degree and good fiber opening uniformity. As a result, the prepreg made using the surface-treated fiberglass cloth has a good appearance and is free of glue holes. Consequently, the printed circuit board made using the prepreg not only has a high yield but also has the advantage of fast signal transmission.

[0038] If the SD is less than 0.35, the fiber opening degree of the fiberglass cloth will be low, meaning the screen area of ​​the fiberglass cloth will be high. When signals pass through the printed circuit board made with this fiberglass cloth, the fiberglass effect is more likely to occur, which will adversely affect the signal transmission rate. Generally, in order to improve the fiber opening degree of the fiberglass cloth, the water pressure used for fiber opening during the fiber opening process will be increased accordingly. If the SD is greater than 0.75, it means that the fiber opening degree of the fiberglass cloth is high. However, due to the excessively high water pressure during fiber opening, many warp and weft yarns in this fiberglass cloth may break, resulting in fuzzy defects on the surface of the fiberglass cloth. This leads to particle defects in the prepreg made with this fiberglass cloth, and bump defects in the printed circuit board made with this prepreg.

[0039] If RA is greater than 0.40, the fiber opening uniformity of the fiberglass cloth will be poor, that is, the size difference of each screen in the fiberglass cloth will be large. This will cause the prepreg made with this fiberglass cloth to have glue holes. During the manufacturing process of printed circuit boards, the prepreg will have excessive expansion and contraction variation, which will cause the printed circuit board to bend or warp, resulting in poor yield of the printed circuit board.

[0040] If the RA / SD value is greater than 1.10, even if the SD is between 0.35 and 0.75 and the RA is between 0.10 and 0.40, the prepreg made using this fiberglass cloth will still have a poor appearance and contain voids, resulting in poor yield of the printed circuit board made using the prepreg. To achieve a better appearance for the prepreg, the RA / SD value is preferably between 0.20 and 1.00; more preferably, the RA / SD value is between 0.20 and 0.90.

[0041] In some embodiments of the present invention, each warp yarn and each weft yarn are composed of multiple monofilaments. The average diameter of the monofilament in each warp yarn ranges from 3.0 μm to 5.0 μm, and the average number of monofilaments ranges from 30 to 200. The average diameter of the monofilament in each weft yarn ranges from 3.0 μm to 5.0 μm, and the average number of monofilaments ranges from 30 to 200. The monofilaments are obtained from glass raw materials through spinning treatment. The glass raw materials are, for example, but not limited to, conventional electronic-grade glass (such as E-glass), low dielectric constant (low K) glass raw materials, low coefficient of thermal expansion (low CTE) glass raw materials, or glass raw materials that have both low dielectric constant and low coefficient of thermal expansion.

[0042] In some embodiments of the present invention, the average thickness of the fiberglass cloth ranges from 10.0 μm to 50.0 μm; the average basis weight of the fiberglass cloth ranges from 10.0 g / m³. 2 Up to 50.0g / m 2 .

[0043] In some embodiments of the present invention, the average weaving density of the warp yarns ranges from 50 yarns / 25.4mm to 100 yarns / 25.4mm, and the average weft yarns range from 50 yarns / 25.4mm to 100 yarns / 25.4mm, based on the average area of ​​the fiberglass cloth.

[0044] The fiberglass cloth is produced from a roll of unopened fiberglass cloth through a process including a fiber-opening treatment. Any known fiber-opening treatment method and equipment are suitable for producing the fiberglass cloth, provided that the resulting fiberglass cloth has an SD value of 0.35 to 0.75, an RA value of 0.10 to 0.40, and an RA / SD value of 0.10 to 1.10, without limiting the specific method and equipment used. In some embodiments of the invention, the fiber-opening treatment is performed by spraying a high-pressure water jet onto the unopened fiberglass cloth using a fiber-opening machine, while simultaneously applying tension to the unopened fiberglass cloth. The tension range is, for example, but not limited to, 50N to 300N, and the water pressure range of the high-pressure water jet is, for example, but not limited to, 20kg to 80kg.

[0045] <Surface-treated fiberglass cloth>

[0046] The surface-treated fiberglass cloth of this invention is obtained by surface treatment of the fiberglass cloth described above. The surface treatment involves reacting the fiberglass cloth with a treatment liquid to alter its properties, enabling the surface-treated fiberglass cloth to interact with resin in subsequent processing. Since the fiberglass cloth possesses both good fiber opening degree and good fiber opening uniformity, the surface-treated fiberglass cloth also consequently possesses these advantages.

[0047] In some embodiments of the present invention, the treatment liquid is prepared using a treatment agent selected from aminosilane coupling agents, alkenylsilane coupling agents, acryloyloxysilane coupling agents, or any combination thereof. The aminosilane coupling agent is, for example, but not limited to (3-aminopropyl)trimethoxysilane. The alkenylsilane coupling agent is, for example, but not limited to vinyltrimethoxysilane. The acryloyloxysilane coupling agent is, for example, but not limited to 3-(methacryloyloxy)propyltrimethoxysilane. In some embodiments of the present invention, the aminosilane coupling agent is (3-aminopropyl)trimethoxysilane, the alkenylsilane coupling agent is vinyltrimethoxysilane, and the acryloyloxysilane coupling agent is 3-(methacryloyloxy)propyltrimethoxysilane.

[0048] <Prepreg>

[0049] The prepreg of the present invention is formed by partially curing an impregnated fabric comprising a resin and a surface-treated fiberglass cloth as described above. More specifically, the preparation of the prepreg includes impregnating the surface-treated fiberglass cloth, which serves as both reinforcement and insulation, in the resin to obtain the impregnated fabric, and then partially curing the impregnated fabric to a partially hardened state (B-stage). Because the surface-treated fiberglass cloth has the advantages of good fiber opening degree and good fiber opening uniformity, i.e., the area ratio of the surface-treated fiberglass cloth to the screen area is low and the size difference of each screen area in the surface-treated fiberglass cloth is small, the area that the surface-treated fiberglass cloth can be filled by the resin is relatively small, thereby giving the prepreg made from the surface-treated fiberglass cloth a good appearance and eliminating glue holes.

[0050] The resin is, for example, but not limited to, thermosetting resin or UV-curable resin. In some embodiments of the present invention, the resin is a thermosetting resin. The thermosetting resin is, for example, but not limited to, polyphenylene ether resin, phenolic resin, epoxy resin, urea-formaldehyde resin, unsaturated polyester, melamine resin, fluoropolymer resin, or bismaleimide triazine resin (BT resin, also known as bismaleimide triazine resin). The UV-curable resin is, for example, but not limited to, photosensitive polyurethane resin or photosensitive acrylic resin. In some embodiments of the present invention, the thermosetting resin is selected from epoxy resin, polyphenylene ether resin, or bismaleimide triazine resin.

[0051] One downstream application of the prepreg includes stacking multiple layers of the prepreg and then adding a copper foil layer on at least one side to form a laminate, followed by hot-pressing the laminate to obtain a copper clad laminate (CCL). In some embodiments of the present invention, the preparation of the prepreg also includes using an inorganic filler to prepare the impregnated fabric. Therefore, the prepreg formed by partially curing the impregnated fabric also contains an inorganic filler to adjust the properties of the copper clad laminate made using the prepreg, such as thermal conductivity, laser drilling capability, and thermal expansion, thereby giving the printed circuit board made using the copper clad laminate better reliability.

[0052] Printed Circuit Boards

[0053] The printed circuit board of the present invention is manufactured using a prepreg as described above. More specifically, the downstream application of the prepreg further includes drilling, gold plating, and etching circuit patterns on the copper foil substrate to obtain the printed circuit board. Therefore, since the prepreg has a good appearance and is free of voids, the printed circuit board manufactured using the prepreg will not have poor yield issues.

[0054] The present invention will be further described with reference to the following embodiments, but it should be understood that the embodiments are for illustrative purposes only and should not be construed as limiting the implementation of the present invention.

[0055] <Example 1>

[0056] Manufacturing of fiberglass cloth: Multiple fiberglass yarns used as warp yarns are sequentially sizing and processed to obtain a warp beam. Then, the warp beam is placed in an air-jet loom (source: Toyota, Japan; model: JAT710) and interwoven with multiple fiberglass yarns used as weft yarns to form a piece of unopened fiberglass cloth. The unopened fiberglass cloth is then sequentially desized and opened to obtain a piece of fiberglass cloth. The original yarn specifications (average monofilament diameter and average number of monofilaments) of the warp and weft yarns, the tension applied to the unopened fiberglass cloth during the opening process, and the water pressure of the high-pressure water jet are shown in Table 1.

[0057] Manufacturing of surface-treated fiberglass cloth: The fiberglass cloth is immersed in the treatment solution for 30 seconds and then dried at 150°C to obtain surface-treated fiberglass cloth. The treatment solution is prepared by hydrolysis reaction of aminosilane coupling agent and aqueous acetic acid at a pH range of 3.5 to 5.5 for 30 minutes. The total amount of the aminosilane coupling agent and the aqueous acetic acid solution is 100 wt%, and the amount of the aminosilane coupling agent is 0.08 wt%.

[0058] Method for manufacturing the prepreg: The surface-treated fiberglass cloth is impregnated in a resin solution to obtain an impregnated cloth, and then the impregnated cloth is cured at 210°C for 6 minutes to obtain a partially cured prepreg. The resin solution is obtained by mixing a resin (specifically, bismaleimide-triazine resin; sourced from Suiye Industrial Co., Ltd.; model BT-0001) and a solvent (specifically, butanone), and the resin content is 50 wt% based on a total resin solution volume of 100 wt%.

[0059] <Examples 2 to 13 and Comparative Examples 1 to 7>

[0060] The differences between Examples 2 to 13 and Comparative Examples 1 to 7 and Example 1 are shown in Tables 1 to 3. By using warp and weft yarns of different raw yarn specifications and different fiber-opening treatment conditions, fiberglass cloths with different degrees of fiber opening and different fiber-opening uniformity were obtained. For the resin solutions used in Examples 2 to 13 and Comparative Examples 1 to 7, if the specific type of resin was epoxy resin (source: Nan Ya Plastics Industrial Co., Ltd.; model: NPEB475 K70), the corresponding solvent was propylene glycol methyl ether, and the resin content was 60 wt% based on a total resin solution volume of 100 wt%, and the impregnated cloth was cured at 190°C for 6 minutes. If the specific type of resin was polyphenylene ether resin (source: SABIC; model: NORYL SA9000), the corresponding solvent was methyl ethyl ketone (MEK), and the resin content was 65 wt% based on a total resin solution volume of 100 wt%, and the impregnated cloth was cured at 180°C for 4 minutes.

[0061] <Evaluation Items>

[0062] The following uses Example 1 as an example to illustrate the specification measurement method of the fiberglass cloth in Examples 1 to 13 and Comparative Examples 1 to 7, as well as the specification measurement method and appearance evaluation method of the prepreg. The measurement results and appearance evaluation results are shown in Tables 1 to 3.

[0063] Average weave density of warp yarns (D) w ), average weave density of weft yarns (D) f Measurement: The surface of the fiberglass cloth of Example 1 was measured using a fabric warp and weft density measuring instrument (source: Textest Instruments; model: FX3250) to obtain the average weaving density of multiple warp yarns and the average weaving density of multiple weft yarns in the fiberglass cloth of Example 1.

[0064] Measurement of the average width (W) of warp yarns and the average width (F) of weft yarns: A 30 cm length of fiberglass cloth from Example 1 was taken and divided into five measurement areas along the width direction. The fiberglass cloth was placed under a microscope (NIKON; model ME600; magnification 5x) to take five photos of each measurement area. Then, the width of each warp yarn and each weft yarn in the photos was measured using image length measurement software (TS-Link). Finally, the average of the width data of the measurement areas (i.e., a total of 5 width data points) was taken to obtain the average width of multiple warp yarns and the average width of multiple weft yarns in the fiberglass cloth of Example 1.

[0065] Warp width total distance (Rw), weft width total distance (R) f The calculation method for ) is as follows:

[0066] R w = The difference between the maximum and minimum widths of multiple warp yarns;

[0067] R f = The difference between the maximum and minimum widths of multiple weft yarns.

[0068] Measurement of the average thickness of the fiberglass cloth: The fiberglass cloth of Example 1, which is 30 cm long and has been divided into five measurement areas, was placed in an electronic micrometer caliper (TESA MICROMASTER IP54; minimum measurement accuracy is 0.001 mm) to measure the thickness of each measurement area. Finally, the average value of the measured thickness data of each measurement area (i.e., a total of 5 thickness data points) was taken to obtain the average thickness of the fiberglass cloth of Example 1.

[0069] Measurement of the average basis weight of the fiberglass cloth: The fiberglass cloth of Example 1 was cut into three equal parts, and each part was further cut into samples with a size of 30cm × 30cm. The samples were then placed on an electronic balance (OHAUS PR224; minimum measurement accuracy 0.0001g) for weight measurement. The basis weight of each sample was calculated using the following formula. Finally, the average of the three basis weight data points was taken to obtain the average basis weight of the fiberglass cloth of Example 1. The formula is: Basis weight of sample = Weight of sample / Area of ​​sample.

[0070] Measurement of resin content in the prepreg: According to the standard test method of IPC-TM-650 2.3.16.1 (1994 edition) "Resin Content of Prepreg Material (Treated Weight)," the fiberglass cloth and prepreg of Example 1 were cut into samples with a size of 20cm × 20cm. The samples were then placed on the electronic balance for weight measurement, and the resin content in the prepreg of Example 1 was calculated using the following formula: Resin content in prepreg = (1 - weight of fiberglass cloth sample / weight of prepreg sample) × 100%.

[0071] Measurement of the average thickness of the prepreg: Take a 30 cm long prepreg of Example 1, divide the prepreg into five measurement areas along the width direction, and place the prepreg in the electronic micrometer caliper to measure the thickness of the measurement area respectively. Finally, take the average value of the thickness data of the measurement area (i.e., a total of 5 thickness data) to obtain the average thickness of the prepreg of Example 1.

[0072] Measurement of the number of pores in the prepreg and evaluation of the prepreg's appearance: The prepreg of Example 1 was cut into samples with a size of 5cm × 5cm. The samples were then observed under a microscope. If pinhole-sized pores were observed on the surface of the sample, these were considered pores. The number of pinhole-like pores on the sample surface was counted. When the number of pores in the prepreg was 0, the appearance of the prepreg was evaluated as good; when the number of pores was 1 to 100, the appearance of the prepreg was evaluated as having some pinholes; when the number of pores was 101 or more, the appearance of the prepreg was evaluated as having obvious pinholes.

[0073] Table 1

[0074]

[0075] Table 2

[0076]

[0077] Table 3

[0078]

[0079] As shown in Tables 1 to 3, the fiberglass cloths of Examples 1 to 13 fully meet the requirements of SD between 0.35 and 0.75, RA between 0.10 and 0.40, and RA / SD values ​​between 0.10 and 1.10, and the surface of the prepreg has no adhesive holes, resulting in a good appearance. In contrast, the fiberglass cloths of Comparative Examples 1 to 7 do not fully meet the requirements of SD between 0.35 and 0.75, RA between 0.10 and 0.40, and RA / SD values ​​between 0.10 and 1.10, and the surface of the prepreg has adhesive holes. The comparison proves that Examples 1 to 13 successfully ensured that the surface of the prepreg was free of adhesive holes by making the fiberglass cloth fully meet the requirements of SD between 0.35 and 0.75, RA between 0.10 and 0.40, and RA / SD values ​​between 0.10 and 1.10.

[0080] In summary, the fiberglass cloth of the present invention, by limiting the SD to between 0.35 and 0.75, the RA to between 0.10 and 0.40, and the RA / SD value to between 0.10 and 1.10, successfully achieves both good fiber opening degree and good fiber opening uniformity. This results in the surface-treated fiberglass cloth of the present invention, made using the fiberglass cloth, also possessing good fiber opening degree and good fiber opening uniformity. Consequently, the prepreg of the present invention, made using the surface-treated fiberglass cloth, has a good appearance and is free of adhesive voids. Consequently, the printed circuit board of the present invention, made using the prepreg, not only has a high yield but also the advantage of fast signal transmission, thus effectively achieving the objectives of the present invention.

[0081] However, the above description is merely an embodiment of the present invention and should not be construed as limiting the scope of the present invention. Any simple equivalent changes and modifications made in accordance with the claims and description of the present invention shall still fall within the scope of the present invention.

Claims

1. A fiberglass cloth, woven from multiple warp yarns and multiple weft yarns of fiberglass yarn, characterized in that: The average fiber opening coefficient (SD) of the fiberglass cloth is between 0.35 and 0.75, the average uniformity coefficient (RA) is between 0.10 and 0.40, and the RA / SD value is between 0.10 and 1.

10. The definitions of SD and RA are as follows. SD = ; DAY = ; W is the average width of the warp yarns, in μm; F is the average width of the weft yarns, in μm; D w The average weave density of the warp yarns is expressed in yarns per 25.4 mm; D f R represents the average weft yarn weave density, expressed in yarns per 25.4 mm. w The width of the warp yarn is the total distance, in μm; and R f The width of the weft yarn is the total distance, in μm.

2. The fiberglass cloth according to claim 1, characterized in that: The RA / SD value is between 0.20 and 1.

00.

3. The fiberglass cloth according to claim 2, characterized in that: The RA / SD value is between 0.20 and 0.

90.

4. The fiberglass cloth according to claim 1, characterized in that: Each warp and weft yarn is composed of multiple monofilaments. The average diameter of a monofilament in each warp yarn ranges from 3.0 μm to 5.0 μm and the average number of monofilaments ranges from 30 to 200. The average diameter of a monofilament in each weft yarn ranges from 3.0 μm to 5.0 μm and the average number of monofilaments ranges from 30 to 200.

5. The fiberglass cloth according to claim 1, characterized in that: The average thickness of the fiberglass cloth ranges from 10.0 μm to 50.0 μm; the average basis weight of the fiberglass cloth ranges from 10.0 g / m³. 2 Up to 50.0g / m 2 Based on the average area of ​​the fiberglass cloth, the average weaving density of the warp yarns ranges from 50 yarns / 25.4mm to 100 yarns / 25.4mm, and the average weft yarns range from 50 yarns / 25.4mm to 100 yarns / 25.4mm.

6. A surface-treated fiberglass cloth, characterized in that: It is obtained by surface treatment of the fiberglass cloth as described in any one of claims 1 to 5, wherein the surface treatment comprises reacting the fiberglass cloth with a treatment liquid to change the properties of the fiberglass cloth, and the treatment liquid is prepared using a treatment agent selected from aminosilane coupling agents, alkenylsilane coupling agents, acryloyloxysilane coupling agents or any combination thereof.

7. A prepreg, characterized in that: It is formed by partially curing an impregnated fabric comprising resin and surface-treated fiberglass cloth as described in claim 6.

8. The prepreg according to claim 7, characterized in that: The resin is a thermosetting resin.

9. The prepreg according to claim 8, characterized in that: The thermosetting resin is selected from phenolic resin, epoxy resin, urea-formaldehyde resin, unsaturated polyester, melamine resin, fluoropolymer, polyphenylene ether resin, or bismaleimide-triazine resin.

10. A printed circuit board, characterized in that: Made using a prepreg comprising any one of claims 7 to 9.

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