Hot-pressing cushion pad
By using the thermally conductive layer and glass fiber cloth formed by thermally conductive liquid curing, combined with the design of the buffer layer, the problem of poor thermal conductivity of kraft paper at high temperatures is solved, and efficient heat conduction and high temperature resistance are achieved.
Patent Information
- Application Number
- CN202311796522.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-25
- Publication Date
- 2025-06-27
AI Technical Summary
The existing kraft paper buffer pads have poor thermal conductivity at high temperatures, which affects product quality.
A thermally conductive layer formed by thermally conductive liquid curing is adopted. The thermally conductive liquid components include ethylene-C hydrocarbon resin, boron nitride, aluminum nitride, polytetrafluoroethylene emulsion, vulcanized silicon rubber, silicone resin, paired adhesive and hollow glass microbeads. The thermally conductive layer is embedded in the glass fiber cloth, and a buffer layer is provided to improve the buffering performance.
The thermal conductivity and thermal uniformity are improved, so that the hot-pressed buffer pad can maintain good thermal conductivity at high temperatures and can withstand up to 460℃, solving the problem of poor thermal conductivity of kraft paper at high temperatures.
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Figure CN120209464A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of buffer pads, and particularly to a hot-pressed buffer pad. Background Art
[0002] Buffer pads are hot-pressed buffer materials widely used in the circuit board industry, which play a role in evenly transferring the working temperature and working pressure of the hot pressing plate during the hot pressing process. In the prior art, kraft paper is usually used as the buffer pad. However, the heat resistance of kraft paper is limited, and it has good elasticity and buffering ability below 230°C and under PM2.5; but when the temperature exceeds 230°C, kraft paper loses its elasticity and buffering ability, and there is no resilience in the voids after stamping, resulting in thermal deterioration of the fibers and poor thermal conductivity uniformity of kraft paper, which affects the quality of the product. Summary of the Invention
[0003] Embodiments of the present invention provide a hot-pressed buffer pad to solve the problem that the poor thermal conductivity uniformity of kraft paper at high temperatures affects the product quality.
[0004] Specifically, the present invention provides a hot-pressed buffer pad, which includes a heat-conducting layer formed by curing a heat-conducting liquid; the components of the heat-conducting liquid are calculated by weight and include: 31-35 parts of ethylene-propylene hydrocarbon resin, 10-12 parts of boron nitride, 12-14 parts of aluminum nitride, 13-16 parts of polytetrafluoroethylene emulsion, 14-17 parts of vulcanized silicone rubber, 8-12 parts of silicone resin, 1-3 parts of an adhesion promoter, and 2-4 parts of hollow glass microspheres.
[0005] Optionally, the heat-conducting layer has a thermal conductivity higher than 2.8 W / m·K, and the dielectric constant of the heat-conducting layer is 3.50 ± 0.03 MHz.
[0006] Optionally, the hollow glass microspheres have a density of 0.1-0.7 g / cc, a compressive strength of 500 psi-18,000 psi, a particle size of 1-200 μm, and a wall thickness of 0.5-1.5 μm.
[0007] Optionally, the hot-pressed buffer pad further includes a fiberglass cloth, and the fiberglass cloth is embedded in the heat-conducting layer.
[0008] Optionally, the hot-pressed buffer pad further includes a buffer layer; the number of the heat-conducting layers is two, and the two heat-conducting layers are respectively arranged on both sides of the buffer layer.
[0009] Optionally, the buffer layer includes a fiber layer, a polymer layer and a tear-resistant layer which are hot-pressed and compounded; the tear-resistant layer is used for bonding one or more of the fiber layer, the polymer layer and the heat-conducting layer.
[0010] Optionally, the fiber layer, the polymer layer, the tensile and tear resistant layer, the polymer layer and the fiber layer are hot-pressed and composited in sequence from top to bottom; and the fiber layer and the heat conductive layer are hot-pressed and composited.
[0011] Optionally, the polymer layer is made of Teflon material; the fiber layer is made of glass fiber material; and the tensile and tear resistant layer is made of fluororesin.
[0012] Optionally, the heat pressing buffer pad further includes a high temperature resistant layer, and the high temperature resistant layer is composited on a side of the heat conductive layer away from the buffer layer.
[0013] Optionally, the high temperature resistant layer is made of Teflon material.
[0014] The beneficial effects of the present invention are:
[0015] The present invention uses ethylene-propylene hydrocarbon resin, polytetrafluoroethylene emulsion, vulcanized silicone rubber and silicone resin as main materials, and adjusts the proportions between the components so that the thermal conductivity and thermal conductivity uniformity of the thermal conductive layer formed after the thermal conductive liquid is cured are high, and can be used as a hot pressing buffer pad. At the same time, since an appropriate proportion of hollow glass microspheres, aluminum nitride and boron nitride are added to the thermal conductive liquid, the high temperature resistance of the material is reasonably utilized, so that the prepared hot pressing buffer pad can withstand a high temperature of up to 460°C. Therefore, the hot pressing buffer pad provided by the present invention can replace kraft paper to solve the problem that kraft paper has poor thermal conductivity uniformity at high temperatures and affects product quality. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.
[0017] Figure 1 Schematic diagram of the structure of a buffer pad in one embodiment of the present invention.
[0018] In the figure: 100, high temperature resistant layer, 200, heat conductive layer, 300, buffer layer, 310, fiber layer, 320, polymer layer, 330, tensile and tear resistant layer. DETAILED DESCRIPTION
[0019] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0020] In the description of the present invention, it should be understood that the terms "longitudinal", "radial", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.
[0021] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0022] Figure 1 is a schematic structural diagram of a buffer pad in one embodiment of the present invention, such as Figure 1 As shown, an embodiment of the present invention provides a hot pressing buffer pad, the hot pressing buffer pad includes a heat conducting layer 200, and the heat conducting layer 200 is formed by curing a heat conducting liquid. The components of the heat conducting liquid are calculated by weight and include: 31-35 parts of ethylene propylene hydrocarbon resin, 10-12 parts of boron nitride, 12-14 parts of aluminum nitride, 13-16 parts of polytetrafluoroethylene emulsion, 14-17 parts of vulcanized silicone rubber, 8-12 parts of silicone resin, 1-3 parts of coupling agent, and 2-4 parts of hollow glass microspheres.
[0023] The present invention uses ethylene-propylene hydrocarbon resin, polytetrafluoroethylene emulsion, vulcanized silicone rubber and silicone resin as main materials, and adjusts the proportions between the components so that the thermal conductivity and thermal uniformity of the thermal conductive layer 200 formed after the thermal conductive liquid is cured are high, and can be used as a hot pressing buffer pad. At the same time, since an appropriate proportion of hollow glass microspheres, aluminum nitride and boron nitride are added to the thermal conductive liquid, the high temperature resistance of the material is reasonably utilized, so that the prepared hot pressing buffer pad can withstand a high temperature of up to 460°C. Therefore, the hot pressing buffer pad provided by the present invention can replace kraft paper to solve the problem that kraft paper has poor thermal conductivity uniformity at high temperatures and affects product quality.
[0024] Furthermore, the thermal conductivity of the thermal conductive layer 200 is higher than 2.8 W / m·K, with an ultra-high thermal conductivity, capable of quickly and evenly conducting heat, and having the matching ability to adapt to different application scenarios; the dielectric constant of the thermal conductive layer 200 is 3.50 ± 0.03 MHz, presenting weak polarity, so it is isotropic during heat conduction, and the thermal conductivity uniformity of the thermal compression buffer pad is high.
[0025] In an embodiment of the present invention, the density of the hollow glass microspheres is 0.1 - 0.7 g / cc, the compressive strength is 500 psi - 18000 psi, the particle size is 1 - 200 μm, and the wall thickness is 0.5 - 1.5 μm. The hollow glass microspheres with such characteristics have good dispersibility and high heat insulation, can be fully mixed with other components in the heat-conducting liquid, and improve the high-temperature resistance performance of the thermal compression buffer pad.
[0026] In an embodiment of the present invention, the thermal compression buffer pad further includes a fiberglass cloth, and the fiberglass cloth is embedded in the thermal conductive layer 200. In the present invention, fiberglass is used as the reinforcing material. After the heat-conducting liquid is coated on the fiberglass cloth during application, part of the heat-conducting liquid penetrates and solidifies into the voids of the fiberglass cloth, and there is no stress inside the obtained thermal conductive layer 200. Therefore, its anti-shrinkage property and isotropy are relatively high.
[0027] In an embodiment of the present invention, the thermal compression buffer pad further includes a buffer layer 300. The number of the thermal conductive layers 200 is two, and the two thermal conductive layers 200 are respectively arranged on both sides of the buffer layer 300. Due to the arrangement of the buffer layer 300, the buffering performance of the thermal compression buffer pad is increased, so that it can return to its original state after stamping, and at the same time, the amount of the thermal conductive layer 200 can be reduced, thereby reducing the cost. At the same time, since the two thermal compression buffer pads are distributed on both sides of the copper-clad substrate, each thermal compression buffer pad is located between the hot plate and the steel plate of the laminator, and the copper-clad substrate is located between the two steel plates, so as to mitigate the heating curve of the copper foil, fixed chips, and protective chips closest to the copper-clad substrate, and make the temperatures of the copper foils, fixed chips, and protective chips in each layer of the multiple copper-clad substrates to be pressed close, so as to ensure the quality during the production of the PCB circuit board.
[0028] In an embodiment of the present invention, the buffer layer 300 includes a fiber layer 310, a polymer layer 320, and a tear-resistant layer 330 that are hot-pressed and compounded; the tear-resistant layer 330 is used to bond one or more of the fiber layer 310, the polymer layer 320, and the heat-conducting layer 200. Further, the fiber layer 310, the polymer layer 320, the tear-resistant layer 330, the polymer layer 320, and the fiber layer 310 are hot-pressed and compounded in sequence from top to bottom; the fiber layer 310 is hot-pressed and compounded with the heat-conducting layer 200. The hot-pressed buffer pad of this embodiment is formed by hot-pressing and compounding the heat-conducting layer 200 and the buffer layer 300. The heat-conducting layer 200 can uniformly and quickly transfer the working temperature of the press, so that the physical and electrical properties of the product after pressing are consistent. The buffer layer 300 is used to buffer the working pressure of the press.
[0029] In an embodiment of the present invention, the hot-pressed buffer pad further includes a high-temperature resistant layer 100, and the high-temperature resistant layer 100 is compounded on the side of the heat-conducting layer facing away from the buffer layer 300. In application, the high-temperature resistant layer 100 is directly in contact with the press, and its high-temperature resistant property can prevent the hot-pressed buffer pad from melting and sticking to the hot pressing plate.
[0030] Specifically, the polymer layer 320 is made of Teflon material; the fiber layer 310 is made of glass fiber material; the tear-resistant layer 330 is made of fluororesin. The high-temperature resistant layer 100 is made of Teflon material. The high-temperature resistant layer 100 prepared from Teflon material has excellent chemical stability and excellent non-stick characteristics, avoiding adhesion to the product or the hot pressing plate. The fiber layer 310 prepared from fiberglass cloth has high ductility and plays a buffering role. The polymer layer 320 prepared from Teflon material can accelerate heat conduction. The tear-resistant layer 330 is prepared from fluororesin, used as an adhesive, plays a role in ventilation, and can increase the buffering property. Preferably, the fluororesin includes one or more of perfluorooctane sulfonyl compounds (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid, and perfluorodecanoic acid.
[0031] The features and properties of the present application will be further described in detail below in conjunction with embodiments.
[0032] Example 1
[0033] This example is used to illustrate the hot-pressed buffer pad disclosed in the present invention. The hot-pressed buffer pad includes a heat-conducting layer 200 formed by curing a heat-conducting liquid. The components of the heat-conducting liquid used to prepare the heat-conducting layer 200 are calculated by weight ratio and include: 33.5 parts of ethylene-propylene hydrocarbon resin, 11.2 parts of boron nitride, 13.4 parts of aluminum nitride, 14.3 parts of polytetrafluoroethylene emulsion, 15.3 parts of vulcanized silicone rubber, 10.1 parts of silicone resin, 2.2 parts of an adhesion promoter, and 3.2 parts of hollow glass microspheres. The particle size of the hollow glass microspheres is 1 to 200 μm.
[0034] Weigh the ethylene-propylene hydrocarbon resin, boron nitride, aluminum nitride, polytetrafluoroethylene emulsion, vulcanized silicone rubber, silicone resin, adhesion promoter and hollow glass microspheres in proportion and configure them into a heat-conducting liquid through a liquid premixing and glue-mixing device. Heat and cure the heat-conducting liquid to obtain a heat-conducting layer blank. Cut the heat-conducting layer blank to obtain the hot-pressing buffer pad.
[0035] Example 2
[0036] The difference between this example and Example 1 is that there are 2.1 parts of hollow glass microspheres.
[0037] Example 3
[0038] The difference between this example and Example 1 is that there are 4 parts of hollow glass microspheres.
[0039] Example 4
[0040] The difference between this example and Example 1 is that there are 12.3 parts of aluminum nitride.
[0041] Example 5
[0042] The difference between this example and Example 1 is that the particle size of the hollow glass microspheres is 500 μm.
[0043] Comparative Example 1
[0044] The difference between this comparative example and Example 1 is that it does not contain hollow glass microspheres.
[0045] Comparative Example 2
[0046] The difference between this comparative example and Example 1 is that there are 0.5 parts of hollow glass microspheres.
[0047] Comparative Example 3
[0048] The difference between this comparative example and Example 1 is that there are 7 parts of hollow glass microspheres.
[0049] Comparative Example 4
[0050] The difference between this comparative example and Example 1 is that it does not contain aluminum nitride.
[0051] Comparative Example 5
[0052] The difference between this comparative example and Example 1 is that there are 10 parts of aluminum nitride.
[0053] Comparative Example 6
[0054] The difference between this comparative example and Example 1 is that there are 17 parts of aluminum nitride.
[0055] Comparative Example 7
[0056] This comparative example is different from Example 1 in that it does not contain boron nitride.
[0057] Comparative Example 8
[0058] This comparative example is different from Example 1 in that it contains 5 parts of boron nitride.
[0059] Comparative Example 9
[0060] This comparative example is different from Example 1 in that it contains 15 parts of boron nitride.
[0061] The hot-pressed buffer pads prepared in Examples 1 to 5 and Comparative Examples 1 - 9 were tested according to domestic / international standard testing methods, and the test results are shown in Table 1:
[0062] Table 1 Test Results of the Hot-Pressed Buffer Pads in Examples 1 - 5 and Comparative Examples 1 - 9
[0063]
[0064] According to the above test results, it can be seen that the buffer pads prepared in Examples 1 - 5 have relatively balanced thermal conductivity, thermal resistance, and volume resistivity, and high thermal conductivity and thermal conductivity uniformity. In Comparative Example 1, hollow glass microspheres were not added, resulting in a significant decrease in its volume resistivity and poor insulation performance. In Comparative Example 4, aluminum nitride was not added, so its thermal conductivity was relatively low, which was not conducive to rapid heat conduction. In Comparative Example 7, boron nitride was not added, resulting in low thermal resistance and a small temperature rise caused by the same amount of heat, which was not conducive to heat conduction.
[0065] Examples 1 - 5 all have relatively high thermal resistance, moderate thermal conductivity, and relatively high volume resistivity, indicating that the added hollow glass microspheres, aluminum nitride, and boron nitride cooperate with ethylene-propylene hydrocarbon resin, polytetrafluoroethylene emulsion, vulcanized silicone rubber, and silicone resin, having the characteristics of high thermal conductivity and thermal conductivity uniformity, and can replace kraft paper to solve the problem of poor thermal conductivity uniformity of kraft paper at high temperatures and affecting product quality.
[0066] The above-described embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.
Claims
1. A hot-pressing buffer pad, characterized in that, The hot pressing buffer pad includes a heat-conducting layer formed by curing a heat-conducting liquid; the components of the heat-conducting liquid are calculated by weight and include: 31-35 parts of ethylene-propylene hydrocarbon resin, 10-12 parts of boron nitride, 12-14 parts of aluminum nitride, 13-16 parts of polytetrafluoroethylene emulsion, 14-17 parts of vulcanized silicone rubber, 8-12 parts of silicone resin, 1-3 parts of coupling agent, and 2-4 parts of hollow glass microspheres.
2. The hot pressing cushion according to claim 1, characterized in that: The thermal conductivity of the thermal conductive layer is higher than 2.8 W / mk.
3. The hot pressing cushion according to claim 1, characterized in that: The hollow glass microspheres have a density of 0.1 to 0.7 g / cc, a compressive strength of 500 psi to 18,000 psi, a particle size of 1 to 200 μm, and a wall thickness of 0.5 to 1.5 μm.
4. The hot pressing cushion according to claim 1, characterized in that: The hot pressing buffer pad also includes glass fiber cloth, and the glass fiber cloth is embedded in the heat conductive layer.
5. The hot pressing cushion according to claim 1, characterized in that: The heat pressing buffer pad also includes a buffer layer; the number of the heat conducting layers is two, and the two heat conducting layers are respectively arranged on both sides of the buffer layer.
6. The hot pressing cushion according to claim 5, characterized in that: The buffer layer comprises a fiber layer, a polymer layer and a tensile tear layer which are heat-pressed and composited; the tensile tear layer is used to bond one or more of the fiber layer, the polymer layer and the heat-conducting layer.
7. The hot pressing cushion according to claim 6, characterized in that: The fiber layer, the polymer layer, the tensile and tear resistant layer, the polymer layer and the fiber layer are hot-pressed and composited in sequence from top to bottom; and the fiber layer and the heat-conducting layer are hot-pressed and composited.
8. The hot pressing cushion according to claim 6, characterized in that: The polymer layer is made of Teflon material; the fiber layer is made of glass fiber material; and the tensile and tear-resistant layer is made of fluororesin.
9. The hot-pressing buffer pad according to claim 4, characterized in that, The heat pressing buffer pad further comprises a high temperature resistant layer, and the high temperature resistant layer is compounded on a side of the heat conducting layer away from the buffer layer.
10. The hot pressing cushion according to claim 9, characterized in that: The high temperature resistant layer is made of Teflon material.