Electronics grade reinforced textile type glass fabric product and method of production

Abstract

This invention discloses an electronic-grade reinforced textile fiberglass cloth product and its production method, belonging to the field of high-performance PCB and copper-clad laminate substrates. The fiberglass cloth is woven from warp yarns and flat-section weft yarns, with a reactive impregnation layer covering the surface of each glass fiber monofilament. Two-dimensional sheet-like nanofillers, preferentially parallel-oriented along the fiber axis, are dispersed within this layer. The production method achieves axial orientation of the nanofillers through a fluid shearing and external field synergistic coating process, followed by low-temperature conditioning to form a semi-cured state and lock the orientation structure. This invention eliminates the need for high-temperature heat cleaning, maximizing the preservation of the fiber's original strength. Furthermore, the synergistic effect of the macroscopically dense weft yarns and the microscopically oriented thermally conductive network of the nanofillers significantly improves the in-plane thermal conductivity of the substrate and reduces dielectric loss, solving the thermal resistance and warping problems caused by resin enrichment at the interlacing points of traditional fiberglass cloth.

Description

Technical Field

[0001] This invention relates to the field of printed circuit board (PCB) and copper clad laminate (CCL) substrates, specifically to an electronic-grade reinforced textile fiberglass cloth and its continuous production method, which is used to improve in-plane thermal conductivity, reduce dielectric loss and improve dimensional stability. Background Technology

[0002] Current electronic-grade fiberglass cloth typically uses starch-based or paraffin-based sizing agents to treat the fiberglass yarn. After weaving, it requires high-temperature calcination to remove organic matter, followed by surface treatment with silane coupling agents. This process has the following problems: Poor interfacial bonding and thermal damage: The high-temperature simmering process consumes a lot of energy and may also damage the strength of the glass fiber itself, leading to embrittlement of the fabric surface.

[0003] Limited dielectric properties: Traditional epoxy-coated fiberglass cloth cannot simultaneously achieve both low dielectric constant and high strength, thus failing to meet the requirements of high-frequency and high-speed PCBs.

[0004] Thermal conduction and warping issues: Fiberglass cloth has low thermal conductivity, and the thermal expansion coefficients of resin and fiberglass do not match, making ultra-thin substrates prone to warping. Summary of the Invention

[0005] The purpose of this invention is to provide an electronic-grade reinforced textile fiberglass cloth product and its continuous production method, aiming to solve the problems of poor thermal conductivity, poor interfacial bonding and high-temperature treatment damage in the existing technology of fiberglass cloth, and to improve the in-plane thermal conductivity of the cloth, reduce dielectric loss and improve dimensional stability.

[0006] The above-mentioned technical objective of the present invention is achieved through the following technical solution: an electronic grade reinforced textile fiberglass cloth product, which is made of interwoven warp and weft yarns; The surfaces of the glass fiber monofilaments of the warp and weft yarns are coated with a reactive impregnation layer; The reactive impregnation layer contains oriented nanofillers, which are two-dimensional sheet-like nanofillers and are preferentially parallel to the glass fiber monofilament axis within the reactive impregnation layer. The weft yarn is a flat-section weft yarn, and the flat-section weft yarn is interwoven with the warp yarn to form a fiberglass cloth.

[0007] Furthermore, the reactive wetting layer is an epoxy-silane composite wetting layer.

[0008] Furthermore, the two-dimensional sheet-like nanofiller is selected from at least one of hexagonal boron nitride and fluorinated graphene.

[0009] Furthermore, the content of the two-dimensional sheet-like nanofiller in the reactive impregnation layer is 0.1wt% to 1.0wt% of the total solid mass of the reactive impregnation layer, and the deflection angle of its sheet extension direction relative to the axis of the glass fiber monofilament is 0° to 15°.

[0010] Furthermore, the aspect ratio of the flat cross-section weft yarn is 2.0 to 4.0.

[0011] The present invention also provides a method for producing the above-mentioned electronic-grade reinforced textile fiberglass cloth product, comprising the following steps: S1, preparing a reactive wetting agent comprising epoxy prepolymer, silane coupling agent, two-dimensional sheet-like nanofiller and solvent; S2, the glass fiber monofilaments are coated through the sizing agent impregnation tank, and before the coated liquid film is completely dry, an electric field parallel to the fiber direction is applied through the electrode plate to cause the two-dimensional sheet-like nanofiller to align along the axial direction of the glass fiber monofilaments to form oriented nanofiller. S3, the fibers treated in step S2 are introduced into a low-temperature conditioning device for low-temperature conditioning to form warp yarns with a reactive impregnation layer on the surface. S4 uses a non-circular die-hole melt drawing process to prepare flat cross-section weft yarn; S5, the warp yarns and the flat-section weft yarns are interwoven into a fabric to obtain the electronic-grade reinforced textile fiberglass cloth product.

[0012] Furthermore, the viscosity of the reactive wetting agent at room temperature is 5 mPa·s to 20 mPa·s; the electric field in step S2 is a combined electric field containing a DC component and a pulse component.

[0013] Furthermore, the intensity of the DC component is 1kV / mm to 3kV / mm, and the intensity of the pulse component is 50V / mm to 100V / mm.

[0014] Furthermore, in step S3, the low-temperature conditioning temperature is 80°C to 120°C, and the low-temperature conditioning time is 1s to 5s, so that the reactive impregnation layer forms a semi-cured state.

[0015] Furthermore, in step S4, the surface of the flat cross-section weft yarn is covered with a reactive impregnation layer; the resulting fiberglass cloth does not undergo a hot cleaning process, and the reactive impregnation layer can be further cured and bonded with the resin system during subsequent pressing.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects: 1. This invention improves the in-plane thermal conductivity of the composite substrate by coating a reactive wetting layer onto the surface of glass fiber monofilaments and applying an electric field parallel to the fiber axis while the liquid film is not completely dry. This causes two-dimensional sheet-like nanofillers to align along the fiber axis, forming continuous or quasi-continuous thermal conductive paths. Even trace amounts of nanofillers in this fabric can form physical connection channels, enabling rapid heat transfer along the fiber direction, reducing local thermal resistance, and improving the heat dissipation efficiency of the board under high-frequency and high-speed application conditions.

[0017] 2. This invention utilizes a low-temperature semi-curing process to fix the oriented nanofillers in the impregnation layer, while maintaining the original strength of the glass fiber and preventing fiber embrittlement caused by high-temperature burning. The flat cross-section weft yarns and warp yarns are tightly interwoven, reducing gaps in the fabric and areas of resin accumulation. This reduces the Z-axis expansion of the fabric under high-temperature pressing or reflow soldering conditions, improving dimensional stability. Furthermore, the impregnation layer and resin matrix undergo chemical co-curing during the pressing process, enhancing the interfacial bonding strength. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of a method for producing electronic-grade reinforced textile fiberglass cloth according to the present invention. Figure 2 This is a schematic diagram illustrating the mechanism of the fluid-external field synergistic coating directional process in the production method of this invention; Figure 3 This is a partial longitudinal cross-sectional schematic diagram of the microstructure of the surface of a single glass fiber in the product of the present invention; Figure 4 The diagram shows a structural comparison between the product of the present invention and the weft yarn interlacing state of different cross sections in the prior art. (a) is a schematic diagram of the traditional circular cross section weft yarn interlacing state, and (b) is a schematic diagram of the flat cross section weft yarn interlacing state in the embodiment of the present invention. Figure 5 The images show a comparison of SEM images of the glass fiber surface impregnation layer cross sections in the embodiments and comparative examples of the present invention. (a) is a cross section of the embodiment of the present invention after external field orientation treatment, and (b) is a cross section of the comparative example without external field orientation treatment.

[0019] In the diagram: 100 - Glass fiber monofilament; 200 - Sizing agent impregnation tank; 210 - Reactive impregnation layer; 300 - Electric field oriented region; 310 - Electrode plate; 400 - Nanofiller aggregate; 410 - Randomly distributed nanofiller; 420 - Directionally arranged nanofiller; 500 - Low-temperature conditioning device; 600 - Warp yarn; 610 - Traditional circular cross-section weft yarn; 620 - Flat cross-section weft yarn; 710 - Traditional large-area resin enrichment zone; 720 - Compressed microscopic resin enrichment zone; h - thickness of reactive impregnation layer; θ - orientation deflection angle of nanofiller; L - length of electric field orientation region; d - electrode spacing; H1 - thickness of conventional fabric undulation; H2 - thickness of fabric undulation in this invention. Detailed Implementation

[0020] To make the technical solution, implementation path and beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 3 As shown, this invention provides an electronic-grade reinforced textile fiberglass cloth product, which is woven from warp yarns 600 and weft yarns. The surfaces of the glass fiber monofilaments 100 of both the warp and weft yarns are coated with a reactive impregnation layer 210, the thickness h of which is uniformly distributed. The reactive impregnation layer 210 is an epoxy-silane composite impregnation layer, containing an epoxy prepolymer and a silane coupling agent, and uniformly dispersed within it are oriented nanofillers 420. The oriented nanofillers 420 are two-dimensional sheet-like nanofillers, selected from at least one of hexagonal boron nitride and fluorinated graphene. The content of the two-dimensional sheet-like nanofillers in the total solid mass of the reactive impregnation layer 210 is 0.1 wt% to 1.0 wt%. Figure 3 The microstructure reveals that within the reactive wetting layer 210, the two-dimensional sheet-like nanofillers are preferentially parallel to the axial direction of the glass fiber monofilament 100. Specifically, the orientation angle θ of the nanofiller's sheet extension direction relative to the axial direction of the glass fiber monofilament 100 is distributed between 0° and 15°. Through the preferential parallel orientation of the microfillers, the filler sheets connect end-to-end or overlap nearby on the surface of the glass fiber monofilament 100, constructing a continuous thermally conductive and insulating pathway, improving the thermal conductivity along the fiber axial direction, and the aligned two-dimensional sheet structure guides the high-frequency electric field distribution, reducing dielectric losses caused by interfacial polarization.

[0022] like Figure 4 As shown in (a) and (b), the fiberglass cloth employs a flat cross-section weft yarn 620 with a cross-sectional length-to-minor axis ratio of 2.0 to 4.0 in its macroscopic structure. The flat cross-section weft yarn 620 interweaves with the warp yarn 600 to form a complete fiberglass cloth structure. Figure 4 As shown in (a), when using traditional circular cross-section weft yarn 610 for interlacing, due to the circular cross-section of the yarn, there are large geometric gaps at the interlacing points of the warp and weft yarns, forming a traditional large-area resin-rich zone 710, resulting in a large thickness H1 of undulation in the traditional fabric surface. However, as... Figure 4As shown in (b), by using the flat cross-section weft yarn 620, the fabric surface undulation thickness is reduced to the fabric surface undulation thickness H2 of this invention. The physical space between the warp yarn 600 and the flat cross-section weft yarn 620 is fully compressed, and the gap at the interlacing point is reduced to the compressed microscopic resin-rich region 720. The reduction of the resin-rich region shortens the interlayer thermal resistance path, making the fibers coated with the high thermal conductivity reactive impregnation layer 210 closer to each other. At the same time, it reduces the Z-axis expansion rate of the substrate during high-temperature pressing and improves the dimensional stability of the fiberglass cloth.

[0023] Combination Figure 1 The flowchart shown illustrates the production method of the electronic-grade reinforced textile fiberglass cloth product of this invention, which includes the following steps. First, step S1 is performed to prepare a reactive wetting agent comprising an epoxy prepolymer, a silane coupling agent, a two-dimensional sheet-like nanofiller, and a solvent, controlling its viscosity at room temperature to be in a low viscosity range of 5 mPa·s to 20 mPa·s. This low viscosity ensures the leveling properties of the wetting agent during coating and prevents the filler from agglomerating due to excessive viscous resistance during fluid shearing.

[0024] Next, we proceed to step S2, the process mechanism of which is as follows: Figure 2 As shown, glass fiber monofilaments 100 are coated at high speed through an impregnation tank 200. After coating, but before the impregnation liquid film has completely dried and evaporated, the fiber enters an electric field orientation region 300 of length L. A combined electric field parallel to the fiber orientation is applied to the liquid film attached to the fiber surface through upper and lower electrode plates 310 with a spacing of d. The combined electric field includes a DC component with an intensity of 1kV / mm to 3kV / mm and a pulse component with an intensity of 50V / mm to 100V / mm. Figure 2 As shown in the enlarged view below, the high-speed motion of the glass fiber monofilament 100 provides hydrodynamic shear force, guiding the disordered distribution of nanofillers 410 in the impregnating agent to produce initial deflection; at the same time, the DC component generated by the electrode plate 310 applies polarization torque to the two-dimensional sheet nanofiller, and the pulse component provides high-frequency perturbation to block the formation of nanofiller agglomerates 400. Finally, under the synergistic effect of multiple fields, the two-dimensional sheet nanofiller is completely oriented and arranged along the axial direction of the glass fiber monofilament 100 to form oriented nanofillers 420.

[0025] Subsequently, step S3 is performed, introducing the fibers treated in step S2 into a low-temperature conditioning device 500 for low-temperature conditioning. The conditioning temperature is set to 80°C–120°C, and the time is controlled between 1s and 5s. Within this range, the solvent in the reactive wetting agent evaporates, and the epoxy and silane undergo partial condensation, causing the reactive wetting layer 210 to form a semi-cured state, thereby locking the spatial position structure of the oriented nanofiller 420 and obtaining the warp yarn 600. In step S4, a flat cross-section weft yarn 620 with a major-minor axis ratio of 2.0–4.0 is prepared using a non-circular die-hole melt drawing process, and its surface is also coated with the reactive wetting layer 210. Finally, step S5 is performed, interlacing the warp yarn 600 and the flat cross-section weft yarn 620 into a fabric. The resulting fiberglass fabric does not require a high-temperature heat cleaning process, and the reactive wetting layer 210 can undergo further secondary curing and bonding with the resin system during subsequent pressing.

[0026] Example 1 provides an electronic fabric product of model 7638. The warp yarn 600 uses EC11-68 specification, and the flat cross-section weft yarn 620 uses EDR13-136 specification, with a cross-sectional aspect ratio controlled at 2.5. 0.5wt% hexagonal boron nitride nanosheets are added to the reactive wetting layer 210, and the reactive wetting agent has a room temperature viscosity of 10 mPa·s. The external field orientation after coating uses a combination of a 2 kV / mm DC voltage and an 80 V / mm pulse voltage. The temperature of the cryogenic conditioning device 500 is controlled at 100°C for 3 seconds. After weaving, the fiberglass fabric requires no heat cleaning, and the tensile strength test reaches 3150 N / 25 mm.

[0027] Example 2 provides an electronic fabric product of model 7628. The warp yarn 600 uses EC11-68 specification, and the flat cross-section weft yarn 620 uses EDR11-68 specification, with a cross-sectional aspect ratio controlled at 3.0. 0.8 wt% fluorinated graphene is added to the reactive impregnation layer 210, and the impregnating agent viscosity is 8 mPa·s. The electrode plate 310 applies a DC component of 2.5 kV / mm and a pulse component of 60 V / mm. The cryogenic conditioning temperature is 90°C for 4 s. The tensile strength after weaving is 3200 N / 25 mm.

[0028] Example 3 provides an electronic fabric product of model 7630. The warp yarn 600 uses EC11-100 specification, and the flat cross-section weft yarn 620 uses EDR11-100 specification, with a cross-sectional aspect ratio of 2.8. 1.0 wt% hexagonal boron nitride is added to the reactive impregnation layer 210, and the impregnating agent viscosity is 15 mPa·s. The combined electric field has a DC component of 1.5 kV / mm and a pulse component of 100 V / mm. The low-temperature conditioning temperature is 110°C for 2 s. The tensile strength after weaving is 3100 N / 25 mm.

[0029] To verify the effectiveness of the microscopic synergistic technology of the present invention, combined with Figure 5 Microscopic morphology comparisons were performed. Comparative Example 1 used a traditional process, without added fillers or external field treatment. The interlacing used traditional circular cross-section weft yarn 610, and it underwent high-temperature heat cleaning at 400°C. Its tensile strength decreased to 2100 N / 25 mm, and its thermal conductivity and dimensional stability were also poor. Comparative Example 2 was set up to verify the effect of an external field. Its formula was the same as Example 1, but no electric field was applied through the electrode plate 310. Figure 5 As shown in (b), the reactive wetting layer 210 has a rough surface and exhibits a disordered distribution of nanofiller 410 inside, accompanied by significant nanofiller agglomerates 400, resulting in a minimal increase in in-plane thermal conductivity. However, as... Figure 5 As shown in (a), after fluid-external field synergistic orientation treatment, the reactive wetting layer 210 on the surface of the glass fiber monofilament 100 in Embodiment 1 of the present invention is dense and uniform, and the two-dimensional sheet-like nanofillers inside form highly consistent oriented nanofillers 420. Furthermore, Comparative Example 3 was set up to verify the synergistic effect of macroscopic morphology. Its microscopic orientation treatment was the same as in Embodiment 1, but a traditional circular cross-section weft yarn 610 was used. Tests showed that the large volume of resin enrichment at the interlacing points interrupted the heat transfer path, resulting in overall thermal conductivity and Z-axis anti-expansion effect that were inferior to those of the embodiment of the present invention. Comprehensive verification shows that the solution of the present invention achieves significant comprehensive technical effects through the combination of microscopic orientation and macroscopic compression.

[0030] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make various modifications and equivalent substitutions to the technical solutions of the present invention, and such modifications and equivalent substitutions should not depart from the spirit and scope of protection of the present invention.

Claims

1. An electronic-grade reinforced textile fiberglass cloth product, woven from warp and weft yarns, characterized in that: The surfaces of the glass fiber monofilaments of the warp and weft yarns are coated with a reactive impregnation layer; The reactive impregnation layer contains oriented nanofillers, which are two-dimensional sheet-like nanofillers and are preferentially parallel to the glass fiber monofilament axis within the reactive impregnation layer. The weft yarn is a flat-section weft yarn, and the flat-section weft yarn is interwoven with the warp yarn to form a fiberglass cloth.

2. The electronic-grade reinforced textile fiberglass cloth product according to claim 1, characterized in that: The reactive wetting layer is an epoxy-silane composite wetting layer.

3. The electronic-grade reinforced textile fiberglass cloth product according to claim 1, characterized in that: The two-dimensional sheet-like nanofiller is selected from at least one of hexagonal boron nitride and fluorinated graphene.

4. The electronic-grade reinforced textile fiberglass cloth product according to claim 1, characterized in that: The content of the two-dimensional sheet-like nanofiller in the reactive impregnation layer is 0.1wt% to 1.0wt% of the total solid mass of the reactive impregnation layer, and the deflection angle of its sheet extension direction relative to the axis of the glass fiber monofilament is 0° to 15°.

5. The electronic-grade reinforced textile fiberglass cloth product according to claim 1, characterized in that: The aspect ratio of the flat cross-section weft yarn is 2.0 to 4.

0.

6. A method for producing an electronic-grade reinforced textile fiberglass cloth product as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1, preparing a reactive wetting agent comprising epoxy prepolymer, silane coupling agent, two-dimensional sheet-like nanofiller and solvent; S2, the glass fiber monofilaments are coated through the sizing agent impregnation tank, and before the coated liquid film is completely dry, an electric field parallel to the fiber direction is applied through the electrode plate to cause the two-dimensional sheet-like nanofiller to align along the axial direction of the glass fiber monofilaments to form oriented nanofiller. S3, the fibers treated in step S2 are introduced into a low-temperature conditioning device for low-temperature conditioning to form warp yarns with a reactive impregnation layer on the surface. S4 uses a non-circular die-hole melt drawing process to prepare flat cross-section weft yarn; S5, the warp yarns and the flat-section weft yarns are interwoven into a fabric to obtain the electronic-grade reinforced textile fiberglass cloth product.

7. The production method according to claim 6, characterized in that: The viscosity of the reactive wetting agent at room temperature is 5 mPa·s to 20 mPa·s; the electric field in step S2 is a combined electric field containing a DC component and a pulse component.

8. The production method according to claim 7, characterized in that: The intensity of the DC component is 1kV / mm to 3kV / mm, and the intensity of the pulse component is 50V / mm to 100V / mm.

9. The production method according to claim 6, characterized in that: In step S3, the low-temperature conditioning temperature is 80°C to 120°C, and the low-temperature conditioning time is 1s to 5s, so that the reactive impregnation layer forms a semi-cured state.

10. The production method according to claim 6, characterized in that: In step S4, the surface of the flat cross-section weft yarn is covered with a reactive impregnation layer; the resulting fiberglass cloth does not undergo a hot cleaning process, and the reactive impregnation layer can be further cured and bonded with the resin system during the subsequent pressing process.

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