Copper-clad plate and electromagnetic sensing structure

Abstract

In order to solve the problems of high dielectric constant and poor wave permeability of a radar electromagnetic sensing structure in the prior art, the utility model provides a copper-clad plate and an electromagnetic sensing structure, the copper-clad plate comprises bonding sheets, a substrate and a copper layer, the substrate comprises a glass layer and / or a PMI foam layer, the bonding sheets are arranged on two sides of the substrate, and the copper layer is arranged on the glass layer and / or the PMI foam layer. The copper layer is arranged on the side, away from the substrate, of the bonding sheet. According to the copper-clad plate provided by the utility model, the dielectric constant and the dielectric loss of the copper-clad plate are optimized, so that the flexibility of receiving electromagnetic signals by an electromagnetic sensing structure is improved, and the attenuation of the electromagnetic signals is avoided; when the copper-clad plate is applied to a radar electromagnetic sensing structure, the wave transmission performance and the structural stability of the electromagnetic sensing structure can be remarkably improved, and the adverse effect of environment temperature change on radar signal receiving is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of low-dielectric and low-loss communication materials, and specifically relates to a copper-clad plate and an electromagnetic sensing structure. Background Art

[0002] With the development of communication technology, electromagnetic devices that receive signals need to use wave-transmitting materials that can absorb electromagnetic waves of various bands to ensure the reception of various possible electromagnetic waves. As an electronic device that uses electromagnetic waves to detect targets, the main structure of radar includes an electromagnetic sensor structure. The design of the electromagnetic sensor structure directly affects the detection area and sensitivity of the radar, that is, it is necessary to ensure that the electromagnetic waves can effectively penetrate the electromagnetic sensor structure without affecting the transmission and reception of radar waves.

[0003] Currently, commonly used radar operating frequency bands include 10.525GHz-X band, 24GHz-K band, 35GHz-Ka band and 77GHz-V band. Among them, the 24GHz-K band is a globally used radar operating frequency band with less interference. For example, some military radars operate at 10GHz, which is susceptible to excessive external interference.

[0004] The material selection of the electromagnetic sensing structure is an important factor affecting the transmission and absorption of electromagnetic waves / microwave signals. At present, the electromagnetic sensing structure in the prior art mostly uses a resin laminate as a substrate, such as a phenolic resin laminate, which has a high dielectric constant and poor wave transmittance. The electromagnetic sensing structure is prepared using this substrate. The high dielectric constant affects the propagation speed of the electromagnetic wave, thereby affecting the detection depth and the timing of the signal. In addition, the electromagnetic sensing structure with poor wave transmittance is not conducive to absorbing electromagnetic wave signals. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a copper clad plate and an electromagnetic sensor structure in view of the problems of high dielectric constant and poor wave transmittance of the radar electromagnetic sensor structure in the prior art.

[0006] The technical solution adopted by the utility model to solve the above technical problems is as follows:

[0007] Provided is a copper clad laminate comprising a bonding sheet, a substrate and a copper layer, wherein the substrate comprises a glass layer and / or a PMI foam layer, the bonding sheet is arranged on both sides of the substrate, and the copper layer is arranged on a side of the bonding sheet away from the substrate.

[0008] Optionally, the thickness of the substrate is ≥0.025 mm, the thickness of the bonding sheet is ≥0.01 mm, and the thickness of the copper layer is ≥1 μm.

[0009] Optionally, the bonding sheet includes a fluorine-containing resin film layer and a hydrocarbon resin film layer, the fluorine-containing resin film layer includes a polytetrafluoroethylene film layer, and the polytetrafluoroethylene film layer and the hydrocarbon resin film layer are composited to obtain the bonding sheet.

[0010] Optionally, the dielectric constant of the copper clad laminate is 1.0 to 1.05, and the dielectric loss is 0.0001 to 0.0008.

[0011] Optionally, when the substrate includes the glass layer, at a frequency of 10 Ghz, the dielectric constant of the bonding sheet and the glass layer after mixed pressing is 1.8 to 4.5.

[0012] Optionally, when the substrate includes the PMI foam layer, at a frequency of 10 Ghz, the dielectric constant of the bonding sheet and the PMI foam layer after mixed pressing is 1.1 to 1.98.

[0013] Optionally, when the substrate includes the PMI foam layer and the glass layer, at a frequency of 10 Ghz, the dielectric constant of the substrate after the PMI foam layer and the glass layer are mixed and pressed is 1.01 to 4.0.

[0014] Optionally, there are multiple glass layers, and the multiple glass layers are arranged on both sides or one side of the PMI foam layer, and the glass layers and the PMI foam layers are mixed and pressed to form the substrate.

[0015] Optionally, there are multiple PMI foam layers, and the multiple PMI foam layers are arranged on both sides or one side of the glass layer, and the PMI foam layer and the glass layer are mixed and pressed to form the substrate.

[0016] On the other hand, the utility model provides an electromagnetic sensing structure, comprising the copper clad plate.

[0017] The beneficial effects of the utility model are:

[0018] The utility model provides a copper-clad laminate, comprising an adhesive sheet, a substrate and a copper layer. The substrate comprises a glass layer and / or a PMI foam layer, that is, the substrate comprises the glass layer or comprises the PMI foam layer, or the substrate is obtained by compounding the glass layer and the PMI foam layer. Since the glass layer has the characteristics of less impurities and high purity, when the substrate comprises the glass plate, it is beneficial to improve the wave transmission of the subsequently prepared electromagnetic sensing structure. Since the PMI foam layer has the advantages of low dielectric constant, high strength and light weight, when the substrate comprises the PMI foam layer, it is beneficial to optimize the dielectric constant and dielectric loss of the copper-clad laminate, thereby improving the flexibility of the electromagnetic sensing structure in receiving electromagnetic signals and avoiding the attenuation of electromagnetic signals. When the substrate comprises the glass layer and the PMI foam layer at the same time, the glass layer and the PMI foam layer are mixed and pressed and then compounded with the adhesive sheet and the copper layer to obtain the copper-clad laminate. The copper-clad laminate is applied to the radar electromagnetic sensing structure, which can significantly improve the wave transmission performance and structural stability of the electromagnetic sensing structure and reduce the adverse effects of ambient temperature changes on radar signal reception. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the substrate structure provided by an embodiment of the utility model;

[0020] Figure 2 It is a schematic diagram of the structure of a copper clad laminate provided in one embodiment of the utility model.

[0021] The reference numerals in the drawings of the specification are as follows:

[0022] 1. Adhesive sheet; 2. Substrate; 21. Glass layer; 22. PMI foam layer; 3. Copper layer; 4. Copper clad laminate. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects solved by the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0024] 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 a limitation on the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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.

[0026] Reference Figure 2 An embodiment of the utility model provides a copper clad laminate 4, including a bonding sheet 1, a substrate 2 and a copper layer 3, wherein the substrate 2 includes a glass layer 21 and / or a PMI foam layer 22, the bonding sheet 1 is arranged on both sides of the substrate 2, and the copper layer 3 is arranged on the side of the bonding sheet 1 away from the substrate 2.

[0027] The copper-clad laminate 4 provided by the utility model comprises a bonding sheet 1, a substrate 2 and a copper layer 3, wherein the substrate 2 comprises a glass layer 21 and / or a PMI foam layer 22, that is, the substrate 2 comprises the glass layer 21 or comprises the PMI foam layer 22, or the substrate 2 is obtained by compounding the glass layer 21 and the PMI foam layer 22. Since the glass layer 21 has the characteristics of less impurities and high purity, when the substrate 2 comprises the glass plate, it is beneficial to improve the wave transmission of the electromagnetic sensing structure prepared subsequently. Since the PMI foam layer 22 has the advantages of low dielectric constant, high strength and light weight, when the substrate 2 comprises the glass plate, it is beneficial to improve the wave transmission of the electromagnetic sensing structure prepared subsequently. When the board 2 includes the PMI foam layer 22, it is beneficial to optimize the dielectric constant and dielectric loss of the copper clad board 4, thereby improving the flexibility of the electromagnetic sensing structure in receiving electromagnetic signals and avoiding or reducing the attenuation of electromagnetic signals; when the substrate 2 includes the glass layer 21 and the PMI foam layer 22 at the same time, the glass layer 21 and the PMI foam layer 22 are mixed and pressed and then compounded with the bonding sheet 1 and the copper layer 3 to obtain the copper clad board 4. The copper clad board 4 is applied to the radar electromagnetic sensing structure, which can significantly improve the wave transmission performance and structural stability of the electromagnetic sensing structure and reduce the adverse effects of ambient temperature changes on radar signal reception.

[0028] In one embodiment, the thickness of the substrate is ≥0.025 mm, the thickness of the bonding sheet is ≥0.01 mm, and the thickness of the copper layer is ≥1 μm.

[0029] In one embodiment, the thickness of the substrate is 0.025 mm to 10 mm, the thickness of the bonding sheet is 0.01 mm to 0.4 mm, and the thickness of the copper layer is 1.5 μm to 70 μm.

[0030] Specifically, when setting the thickness of the bonding sheet, the thickness of the substrate and the thickness of the copper layer, on the one hand, it is necessary to set them according to the total thickness preset by the mold of the prepared copper clad laminate; on the other hand, when setting the thickness of the bonding sheet, the substrate and the copper layer, the influence on the dielectric constant also needs to be considered; in addition, regarding the setting of the thickness of the bonding sheet, it is also necessary to consider the relationship between the thickness and laser curing (when the thickness of the bonding sheet is thicker, the corresponding laser time needs to be extended accordingly) to prevent the bonding sheet from being too thick or too thin and affecting the overall performance of the copper clad laminate.

[0031] Specifically, the thickness of the substrate may be 0.025 mm, 0.05 mm, 0.10 mm, 0.50 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm or 10 mm; the thickness of the bonding sheet may be 0.01 mm, 0.05 mm, 0.15 mm, 0.20 mm, 0.25 mm, 0.30 mm, 0.35 mm or 0.40 mm; the thickness of the copper layer may be 1.5 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 55 μm, 60 μm, 65 μm or 70 μm.

[0032] In one embodiment, the glass layer 21 includes quartz glass or ordinary glass.

[0033] Specifically, the glass layer 21 is used in an electromagnetic signal receiving and transmitting device and has good wave transmission performance. This is because the glass itself has the characteristics of high purity and few impurities, which is conducive to the reception of electromagnetic signals. In addition, since glass has a low absorption of millimeter waves and there are scattering and reflection phenomena, which affect the absorption of millimeter wave signals, therefore, selecting a special glass material with high transparency and low scattering and reflection is the key to improving the radar signal receiving efficiency. In a specific preferred embodiment, the glass layer 21 is preferably quartz glass.

[0034] In one embodiment, the bonding sheet 1 includes a fluorine-containing resin film layer and a hydrocarbon resin film layer, the fluorine-containing resin film layer includes a polytetrafluoroethylene film layer, and the polytetrafluoroethylene film layer and the hydrocarbon resin film layer are composited to obtain the bonding sheet 1.

[0035] It should be noted that different types of resins have different dielectric constants and dielectric loss factors. Traditional epoxy resins usually have higher dielectric constants due to their large number of polar groups, while resins with low polarization molecular structures, such as polytetrafluoroethylene, can achieve low dielectric constants and low losses.

[0036] Specifically, the fluorine-containing resin film layer includes a polytetrafluoroethylene film layer, and the polytetrafluoroethylene film layer mainly includes polytetrafluoroethylene. The polytetrafluoroethylene has excellent mechanical properties, can withstand strong acids and alkalis, and has good corrosion resistance. Based on the above excellent performance, in this application, the fluorine-containing resin film layer is used as a carrier and compounded with the hydrocarbon resin film layer to obtain the bonding sheet 1, and the bonding sheet 1 is compounded with the substrate 2 and the copper layer 3 to obtain the copper clad laminate 4 described in the utility model.

[0037] The specific preparation process of the bonding sheet 1 includes:

[0038] Using polytetrafluoroethylene resin powder as raw material, removing impurities and uneven particles, placing the screened polytetrafluoroethylene powder into a mold for pre-pressing; placing the pre-pressed polytetrafluoroethylene resin powder into a sintering furnace, sintering at high temperature, so that the polytetrafluoroethylene resin powder particles are melted and combined to form a uniform and dense polytetrafluoroethylene film layer; the sintered polytetrafluoroethylene film layer needs to be stretched to improve its toughness and ductility; compounding the heat-conductive hydrocarbon resin slurry with the above-mentioned sintered polytetrafluoroethylene film layer to obtain the bonding sheet 1.

[0039] In one embodiment, the dielectric constant of the copper clad board 4 is 1.0-1.05, and the dielectric loss is 0.0001-0.0008.

[0040] Specifically, the bonding sheet 1 of the copper clad laminate 4 described in the present application includes a polytetrafluoroethylene film layer, and the substrate 2 of the copper clad laminate 4 includes a glass layer 21 and / or a PMI foam layer 22. The copper clad laminate 4 prepared by compositely combining the bonding sheet 1 and the substrate 2 has a dielectric constant and dielectric loss that are optimized compared to the existing copper clad laminate 4 (for example, a metal-based copper clad laminate 4 with a dielectric constant of 6.23 and a dielectric loss factor of 0.0014). The copper clad laminate 4 with a low dielectric constant and low dielectric loss is applied to an electromagnetic sensing structure, which is beneficial to improving the wave transmittance of the relevant signal receiving structure and further improving the flexibility of electromagnetic signal reception.

[0041] In one embodiment, when the substrate 2 includes the glass layer 21 , at a frequency of 10 GHz, the dielectric constant of the bonding sheet 1 and the glass layer 21 is mixed and pressed in a range of 1.8 to 4.5.

[0042] It should be noted that the inventors have previously conducted a large number of experimental tests on the dielectric constants of the glass layer 21 and the bonding sheet 1 described in this application before mixing, and found that at a frequency of 10Ghz, the dielectric constant of the glass layer 21 is between 2.0 and 4.5, and the dielectric constant of the bonding sheet 1 is between 1.8 and 2.3. In this application, after the bonding sheet 1 and the glass layer 21 are mixed, the dielectric constant of the two after mixing is detected to be 1.8 to 4.5 at a frequency of 10Ghz, that is, the dielectric constant is reduced after mixing. This is because the overall dielectric constant of the two is optimized after mixing, resulting in a composite layer with a relatively low dielectric constant, while at the same time exerting the excellent wave transmission performance of the glass layer 21.

[0043] In one embodiment, when the substrate 2 includes the PMI foam layer 22 , at a frequency of 10 Ghz, the dielectric constant of the bonding sheet 1 and the PMI foam layer 22 after being mixed and pressed is 1.1-1.98.

[0044] The inventors have previously tested the dielectric constant of the PMI foam layer 22 used in the present application and found that the dielectric constant of the PMI foam layer 22 at 10Ghz frequency is 1.01-1.98. The dielectric constant of the bonding sheet 1 at 10Ghz frequency has been measured to be 1.8-2.3. Compared with the dielectric constant of the bonding sheet 1 and the dielectric constant of the PMI foam layer 22 before mixing, the dielectric constant measured after the two are mixed is 1.1-1.98. Since the PMI foam layer 22 itself has the advantages of low dielectric constant and light weight, the dielectric constant of the bonding sheet 1 and the PMI foam layer 22 as a whole is optimized after mixing. That is, when the PMI foam layer 22 is included in the substrate 2, it is beneficial to optimize the dielectric constant and dielectric loss of the copper clad laminate 4. The copper clad laminate 4 is applied to the relevant electromagnetic sensing structure, which is beneficial to improve the receiving strength of the electromagnetic signal and avoid the attenuation of the electromagnetic signal.

[0045] Reference Figure 1 In one embodiment, when the substrate 2 includes the PMI foam layer 22 and the glass layer 21, at a frequency of 10 Ghz, the dielectric constant of the substrate 2 after the PMI foam layer 22 and the glass layer 21 are mixed and pressed is 1.01 to 4.0.

[0046] Specifically, when the substrate 2 includes both the PMI foam layer 22 and the glass layer 21, a substrate 2 with a low dielectric constant can be obtained. At the same time, the copper-clad board 4 prepared from the substrate 2 has high wave transmittance when used in a corresponding sensing device, thereby better receiving electromagnetic signals.

[0047] In one embodiment, there are a plurality of glass layers 21 , and the plurality of glass layers 21 are disposed on both sides or one side of the PMI foam layer 22 . The glass layers 21 and the PMI foam layer 22 are mixed and pressed to form the substrate 2 .

[0048] Specifically, according to the preparation requirements of the copper clad laminate 4, the glass layer 21 can be selectively set as a single layer, two layers or multiple layers. When a single layer is set, the glass layer 21 is set on one side of the PMI foam layer 22. When two layers or more layers are set, the glass layer 21 can be set on both sides of the PMI foam layer 22 (such as Figure 1 ).

[0049] In one embodiment, there are a plurality of PMI foam layers 22 , and the plurality of PMI foam layers 22 are disposed on both sides or one side of the glass layer 21 . The PMI foam layer 22 and the glass layer 21 are mixed and pressed to form the substrate 2 .

[0050] Specifically, the PMI foam layer 22 may be selectively configured as a single layer, two layers, or multiple layers according to the preparation requirements of the copper clad laminate 4 .

[0051] In another embodiment, the utility model provides an electromagnetic sensing structure, including the copper clad plate 4 described above.

[0052] Specifically, the electromagnetic sensing structure includes the copper clad laminate 4 described in the present application, and the substrate 2 of the copper clad laminate 4 includes a glass layer 21 and / or a PMI foam layer 22, that is, the substrate 2 includes the glass layer 21 or includes the PMI foam layer 22, or the glass layer 21 and the PMI foam layer 22 are combined to obtain the substrate 2. Since the glass layer 21 has the characteristics of less impurities and high purity, when the substrate 2 includes the glass plate, it is beneficial to improve the wave transmission of the subsequently prepared electromagnetic sensing structure. Since the PMI foam layer 22 has the advantages of low dielectric constant, high strength and light weight; when the substrate 2 includes the glass plate When the board 2 includes the PMI foam layer 22, it is beneficial to optimize the dielectric constant and dielectric loss of the copper clad board 4, thereby improving the flexibility of the electromagnetic sensing structure in receiving electromagnetic signals and avoiding or reducing the attenuation of electromagnetic signals; when the substrate 2 includes the glass layer 21 and the PMI foam layer 22 at the same time, the glass layer 21 and the PMI foam layer 22 are mixed and pressed and then compounded with the bonding sheet 1 and the copper layer 3 to obtain the copper clad board 4. The copper clad board 4 is applied to the radar electromagnetic sensing structure, which can significantly improve the wave transmission performance and structural stability of the electromagnetic sensing structure and reduce the adverse effects of ambient temperature changes on radar signal reception.

[0053] Specifically, the copper clad laminate 4 described in the present application can also be used in gas sensing devices. Due to its low dielectric constant, it is used in gas sensing / detection devices, which is beneficial to the rapid transmission and calculation of electromagnetic signals in the medium, and then quickly detects the particle concentration and gas composition in the gas.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A copper clad laminate, characterized in that: The invention comprises a bonding sheet, a substrate and a copper layer. The substrate comprises a glass layer and / or a PMI foam layer. The bonding sheet is arranged on both sides of the substrate. The copper layer is arranged on the side of the bonding sheet away from the substrate.

2. A copper clad laminate according to claim 1, characterized in that: The thickness of the substrate is ≥ 0.025 mm, and the thickness of the bonding sheet is ≥ 0.01mm, and the thickness of the copper layer is ≥1μm.

3. A copper clad laminate according to claim 1, characterized in that: The bonding sheet comprises a fluorine-containing resin film layer and a hydrocarbon resin film layer, the fluorine-containing resin film layer comprises a polytetrafluoroethylene film layer, and the polytetrafluoroethylene film layer and the hydrocarbon resin film layer are composited to obtain the bonding sheet.

4. A copper clad laminate according to claim 1, characterized in that: The dielectric constant of the copper clad laminate is 1.0-1.05, and the dielectric loss is 0.0001-0.0008.

5. The copper clad laminate according to claim 1, characterized in that: When the substrate includes the glass layer, at a frequency of 10 Ghz, the dielectric constant of the bonding sheet and the glass layer after mixed pressing is 1.8 to 4.

5.

6. A copper clad laminate according to claim 1, characterized in that: When the substrate includes the PMI foam layer, at a frequency of 10 Ghz, the dielectric constant of the bonding sheet and the PMI foam layer after mixed pressing is 1.1 to 1.

98.

7. The copper clad laminate according to claim 1, characterized in that: When the substrate includes the PMI foam layer and the glass layer, at a frequency of 10 Ghz, the dielectric constant of the substrate after the PMI foam layer and the glass layer are mixed and pressed is 1.01 to 4.

0.

8. A copper clad laminate according to claim 7, characterized in that: There are a plurality of glass layers, and the plurality of glass layers are arranged on both sides or one side of the PMI foam layer. The glass layers and the PMI foam layers are mixed and pressed to form the substrate.

9. The copper clad laminate according to claim 7, characterized in that: There are a plurality of PMI foam layers, and the plurality of PMI foam layers are arranged on both sides or one side of the glass layer. The PMI foam layers are mixed and pressed with the glass layer to form the substrate.

10. An electromagnetic sensing structure, characterized in that: The copper-clad laminate comprises the copper-clad laminate according to any one of claims 1 to 9.

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