Active electromagnetic functional structure, manufacturing method and aircraft

Abstract

The invention provides an active electromagnetic functional structure, a manufacturing method and an aircraft. The structure comprises a front protective layer, a front buffer layer, a component, a functional layer, a substrate layer, a feed layer, a back buffer layer and a back protective layer which are sequentially arranged from the front to the back. The substrate layer is made of a printed circuit dielectric plate material, the front protective layer and the back protective layer are both made of a resin-based wave-transparent material, and the front buffer layer and the back buffer layer are both made of a wave-transparent foam material; the front buffer layer, the component and the functional layer are cured into a whole through a thermal bonding process, the back buffer layer and the feed layer are cured into a whole through a thermal bonding process, and the front protective layer and the back protective layer are respectively cured into a whole with the front buffer layer and the back buffer layer through a compression molding process. According to the technical scheme, the technical problem that in the prior art, components of an active electromagnetic functional structure cannot be effectively protected is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic functional structures, and in particular to an active electromagnetic functional structure, a manufacturing method and an aircraft. Background Art

[0002] Once traditional electromagnetic functional structures (such as frequency selective surfaces, metamaterials, metasurfaces, etc.) are designed and processed, their working characteristics and implementation effects are basically fixed, and they cannot be adjusted in the face of changing environments in actual applications. At present, some researchers have introduced components such as switching diodes and varactor diodes into the design of electromagnetic functional structures to achieve adjustable working characteristics. A large number of components are loaded to the appropriate positions on the electromagnetic functional structure and controlled by DC excitation signals to obtain the corresponding control functions. However, since active electromagnetic functional structures generally use switching diodes or varactor diodes as control elements, they have a certain package size and will protrude from the surface of the dielectric substrate after installation. They are easy to fall off or damage after being pressed or bumped, and cannot meet specific usage environments.

[0003] At present, in order to solve the problem that the diodes welded on the printed circuit board are easy to fall off, there is a plan to use potting glue to protect the device, but the potting glue is mainly used for waterproofing and flame retardancy, and its dielectric loss is relatively large, which has a great impact on the electrical properties of the electromagnetic functional structure, especially the wave transmission performance. Although there are related studies on active electromagnetic functional structures, they are generally focused on design and principle verification, and there are no public reports on the preparation of active electromagnetic functional structure component protection. Summary of the invention

[0004] The present invention provides an active electromagnetic functional structure, a manufacturing method and an aircraft, which can solve the technical problem in the prior art that components of the active electromagnetic functional structure cannot be effectively protected.

[0005] According to one aspect of the present invention, there is provided an active electromagnetic functional structure, the structure comprising a front protection layer, a front buffer layer, components, a functional layer, a substrate layer, a feed layer, a back buffer layer and a back protection layer arranged in sequence from the front to the back;

[0006] The substrate layer is a printed circuit dielectric board material, the functional layer is a metal periodic array pattern placed on the substrate layer, the feed layer is a metal series and / or parallel line pattern placed on the substrate layer, the front protection layer and the back protection layer are both resin-based wave-transmitting materials, and the front buffer layer and the back buffer layer are both wave-transmitting foam materials;

[0007] The substrate layer, functional layer and feed layer are obtained through the printed circuit board process, the components are soldered on the functional layer, the front buffer layer is solidified into one with the components and the functional layer through a thermal bonding process, the back buffer layer is solidified into one with the feed layer through a thermal bonding process, and the front protective layer and the back protective layer are solidified into one with the front buffer layer and the back buffer layer respectively through a compression molding process.

[0008] Furthermore, the component is a varactor diode and / or a switching diode array.

[0009] Furthermore, the resin-based wave-transmitting material is selected from quartz cloth / epoxy resin prepreg or quartz cloth / cyanate resin prepreg.

[0010] Furthermore, the wave-transmitting foam material is an epoxy foam film.

[0011] Furthermore, the printed circuit dielectric board material is a polytetrafluoroethylene board.

[0012] Furthermore, the thickness of the front protection layer and the back protection layer are both 0.1 mm to 0.5 mm, the relative dielectric constants are both 2.5 to 3.5, and the loss tangent values ​​are both less than or equal to 0.015.

[0013] Furthermore, the thickness of the front buffer layer and the back buffer layer are both 0.3 mm to 1.5 mm.

[0014] According to another aspect of the present invention, an aircraft is provided, the aircraft comprising the active electromagnetic functional structure proposed above in the present invention.

[0015] According to another aspect of the present invention, there is provided a method for manufacturing an active electromagnetic functional structure, the method comprising:

[0016] S1, using a printed circuit board process to prepare a substrate layer, a functional layer on the front side thereof, and a feed layer on the back side thereof, wherein the substrate layer is a printed circuit dielectric board material, the functional layer is a metal periodic array pattern, and the feed layer is a metal series and / or parallel line pattern;

[0017] S2, soldering components onto the functional layer;

[0018] S3, cutting a front epoxy foam film used as a front buffer layer and a back epoxy foam film used as a back buffer layer according to the shape of the active electromagnetic functional structure, and cutting a thickness of the front epoxy foam film according to the height and foaming ratio of the electronic components;

[0019] S4, in an operating environment with a temperature of 25±5°C and a relative humidity of ≤65%, lay the front epoxy foam film on the surface of the components and the back epoxy foam film on the surface of the feed layer, and heat it with hot air at a temperature not higher than 70°C to remove bubbles and stick the film firmly;

[0020] S5, placing the active electromagnetic functional structure with the adhesive film attached in S4 flat in the curing equipment, with a curing pressure of 0.3±0.02MPa, heating from room temperature at a heating rate of 1-2°C / min, and curing according to a stage curing process of 90°C / 2h. After the curing is completed, the heat source is turned off, and the temperature is naturally lowered to below 40°C to release the pressure;

[0021] S6, laying quartz cloth / epoxy resin prepreg with a thickness of 0.2 mm on the mold, placing the active electromagnetic functional structure obtained in S5 into the mold, laying quartz cloth / epoxy resin prepreg with a thickness of 0.2 mm on it, curing by heating and pressurizing, demolding and machining to obtain the final active electromagnetic functional structure.

[0022] The technical solution of the present invention is applied to provide an active electromagnetic functional structure, a manufacturing method and an aircraft. The structure obtains a substrate layer and a functional layer and a feed layer thereon through a printed circuit board process, and solders components on the functional layer. On the one hand, a soft front buffer layer is used to protect the components, and on the other hand, a "3+2" sandwich structure of two protective layers, two buffer layers and one substrate layer is used to enhance the overall mechanical properties of the active electromagnetic functional structure. The structure has the characteristics of simple process, low profile height, and little effect on the electrical properties of the active electromagnetic functional structure, which is of great significance for the engineering application of the active electromagnetic functional structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 A cross-sectional schematic diagram of an active electromagnetic functional structure provided according to a specific embodiment of the present invention is shown.

[0025] The above drawings include the following reference numerals:

[0026] 1. Front protection layer; 2. Front buffer layer; 3. Components; 4. Functional layer; 5. Substrate layer; 6. Feed layer; 7. Back buffer layer; 8. Back protection layer. DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0029] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0030] like Figure 1 As shown, according to a specific embodiment of the present invention, an active electromagnetic functional structure is provided, which includes a front protection layer 1, a front buffer layer 2, components 3, a functional layer 4, a substrate layer 5, a feed layer 6, a back buffer layer 7 and a back protection layer 8 arranged in sequence from the front to the back;

[0031] The substrate layer 5 is a printed circuit dielectric board material, the functional layer 4 is a metal periodic array pattern placed on the substrate layer 5, the feed layer 6 is a metal series and / or parallel line pattern placed on the substrate layer 5, the front protection layer 1 and the back protection layer 8 are both resin-based wave-transmitting materials, and the front buffer layer 2 and the back buffer layer 7 are both wave-transmitting foam materials;

[0032] The substrate layer 5, the functional layer 4 and the feed layer 6 are obtained through a printed circuit board process, the components 3 are soldered on the functional layer 4, the front buffer layer 2 is solidified into one with the components 3 and the functional layer 4 through a thermal bonding process, the back buffer layer 7 is solidified into one with the feed layer 6 through a thermal bonding process, and the front protective layer 1 and the back protective layer 8 are solidified into one with the front buffer layer 2 and the back buffer layer 7 respectively through a compression molding process.

[0033] By applying this configuration, an active electromagnetic functional structure is provided. The substrate layer and the functional layer and feed layer thereon are obtained by a printed circuit board process, and the components are welded on the functional layer. On the one hand, a soft front buffer layer is used to protect the components. On the other hand, a "3+2" sandwich structure of two protective layers, two buffer layers and one substrate layer is used to enhance the overall mechanical properties of the active electromagnetic functional structure. The structure has the characteristics of simple process, low profile height, and little effect on the electrical properties of the active electromagnetic functional structure, which is of great significance for the engineering application of the active electromagnetic functional structure. Compared with the prior art, the technical solution of the present invention can solve the technical problem that the components of the active electromagnetic functional structure cannot be effectively protected in the prior art.

[0034] In one embodiment of the present invention, the component 3 is a varactor diode and / or a switching diode array, the resin-based wave-transmitting material is selected from quartz cloth / epoxy resin prepreg (composite material) or quartz cloth / cyanate resin prepreg (composite material), the wave-transmitting foam material is an epoxy foam film, which belongs to a medium-low temperature curing foam film, and the foaming ratio is 2-3, and the printed circuit dielectric board material is a polytetrafluoroethylene sheet, which has a certain flexibility and can be bent into a developable surface, which is convenient for preparing a conformal active electromagnetic functional structure. The thickness of the front protective layer 1 and the back protective layer 8 are both 0.1mm-0.5mm, the relative dielectric constant is 2.5-3.5, and the loss tangent value is less than or equal to 0.015. The thickness of the front buffer layer 2 and the back buffer layer 7 are both 0.3mm-1.5mm.

[0035] According to another aspect of the present invention, an aircraft is provided, the aircraft comprising the active electromagnetic functional structure proposed in the present invention. Since the active electromagnetic functional structure proposed in the present invention can enhance the overall mechanical properties of the active electromagnetic functional structure while protecting components, and has little effect on the electrical properties of the active electromagnetic functional structure, applying it to the aircraft can significantly improve the performance of the aircraft.

[0036] According to another aspect of the present invention, there is provided a method for manufacturing an active electromagnetic functional structure, the method comprising:

[0037] S1, using a printed circuit board process to prepare a substrate layer, a functional layer on the front side thereof, and a feed layer on the back side thereof, wherein the substrate layer is a printed circuit dielectric board material, the functional layer is a metal periodic array pattern, and the feed layer is a metal series and / or parallel line pattern;

[0038] S2, soldering components onto the functional layer;

[0039] S3, cutting a front epoxy foam film used as a front buffer layer and a back epoxy foam film used as a back buffer layer according to the shape of the active electromagnetic functional structure, and cutting a thickness of the front epoxy foam film according to the height and foaming ratio of the electronic components;

[0040] S4, in an operating environment with a temperature of 25±5°C and a relative humidity of ≤65%, lay the front epoxy foam film on the surface of the components and the back epoxy foam film on the surface of the feed layer, and heat it with hot air at a temperature not higher than 70°C to remove bubbles and stick the film firmly;

[0041] S5, placing the active electromagnetic functional structure with the adhesive film attached in S4 flat in the curing equipment, with a curing pressure of 0.3±0.02MPa, heating from room temperature at a heating rate of 1-2°C / min, and curing according to a stage curing process of 90°C / 2h. After the curing is completed, the heat source is turned off, and the temperature is naturally lowered to below 40°C to release the pressure;

[0042] S6, laying quartz cloth / epoxy resin prepreg with a thickness of 0.2 mm on the mold, placing the active electromagnetic functional structure obtained in S5 into the mold, laying quartz cloth / epoxy resin prepreg with a thickness of 0.2 mm on it, curing by heating and pressurizing, demolding and machining to obtain the final active electromagnetic functional structure.

[0043] In order to further understand the present invention, the following Figure 1 The active electromagnetic functional structure and manufacturing method of the present invention are described in detail.

[0044] like Figure 1 As shown, the substrate layer uses a 0.508mm polytetrafluoroethylene sheet, which has certain flexibility and can be bent into a developable surface, making it easy to prepare a conformal active electromagnetic functional structure. The functional layer and the feed layer are both made of 35μm thick metal copper and are prepared on both sides of the substrate layer through the printed circuit board process. The components are MA46H120 series varactor diodes, with three-dimensional dimensions of 0.3mm*0.7mm*0.2mm, of which the thickness is 0.2mm.

[0045] Both the front and back buffer layers are made of J208F medium and low temperature curing epoxy foam film. The manufacturing process is divided into three steps: cutting, laying, and molding. The details are as follows:

[0046] Cutting: For the front buffer layer, the foam film is cut according to the shape of the active electromagnetic functional structure. The thickness of the foam film to be cut is determined according to the height of the electronic components to be covered and the foaming ratio. The thickness of the diode is 0.2mm and the foaming ratio is 2.5. Therefore, the thickness of the foam film is specifically 0.08mm. Considering factors such as measurement errors, it is actually set to 0.1mm. For the back buffer layer, the foam film is cut according to the shape of the active electromagnetic functional structure.

[0047] Laying: The operating environment temperature is 25±5℃, and the relative humidity is ≤65%. Use tweezers to peel off the kraft paper on one side of the film, and then lay it on the surface of the components to be glued. When laying, pay attention to eliminate bubbles and protect the components from damage. At the same time, peel off the kraft paper on the other side of the film, and use a hair dryer to heat and laminate (the local temperature must not be higher than 70℃), further adhere the film, and remove bubbles;

[0048] Molding: Place the active electromagnetic functional structure obtained after laying the adhesive film flat in the curing equipment, with a curing pressure of 0.30±0.02MPa, and heat up from room temperature at a rate of 1-2℃ / min, and cure according to a staged curing process of 90℃ / 2h. After the curing is completed, turn off the heat source, cool naturally to below 40℃ and release the pressure;

[0049] The protective layer is made of quartz cloth / cyanate resin prepreg with a thickness of 0.2 mm. First, the 0.2 mm quartz cloth / cyanate resin prepreg is laid on the mold, and then the active electromagnetic functional structure including the buffer layer is aligned and placed, and finally 0.2 mm quartz cloth / cyanate resin prepreg is laid on it again, and then heated, pressurized and cured, and then demolded and machined.

[0050] In summary, the present invention provides an active electromagnetic functional structure, a manufacturing method and an aircraft. The structure obtains a substrate layer and a functional layer and a feed layer thereon through a printed circuit board process, and solders components on the functional layer. On the one hand, a soft front buffer layer is used to protect the components. On the other hand, a "3+2" sandwich structure of two protective layers, two buffer layers and one substrate layer is used to enhance the overall mechanical properties of the active electromagnetic functional structure. The structure has the characteristics of simple process, low profile height, and little effect on the electrical properties of the active electromagnetic functional structure, which is of great significance for the engineering application of the active electromagnetic functional structure. Compared with the prior art, the technical solution of the present invention can solve the technical problem that the components of the active electromagnetic functional structure cannot be effectively protected in the prior art.

[0051] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0052] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An active electromagnetic functional structure, characterized in that: The structure comprises a front protection layer (1), a front buffer layer (2), components (3), a functional layer (4), a substrate layer (5), a feed layer (6), a back buffer layer (7) and a back protection layer (8) which are arranged in sequence from the front to the back; The substrate layer (5) is a printed circuit dielectric board material, the functional layer (4) is a metal periodic array pattern disposed on the substrate layer (5), the feed layer (6) is a metal series and / or parallel line pattern disposed on the substrate layer (5), the front protection layer (1) and the back protection layer (8) are both resin-based wave-transmitting materials, and the front buffer layer (2) and the back buffer layer (7) are both wave-transmitting foam materials; The substrate layer (5), the functional layer (4) and the feed layer (6) are obtained through a printed circuit board process, the components (3) are welded on the functional layer (4), the front buffer layer (2) is solidified into one with the components (3) and the functional layer (4) through a thermal bonding process, the back buffer layer (7) is solidified into one with the feed layer (6) through a thermal bonding process, and the front protective layer (1) and the back protective layer (8) are solidified into one with the front buffer layer (2) and the back buffer layer (7) respectively through a compression molding process.

2. The structure according to claim 1, characterized in that: The component (3) is a varactor diode and / or a switching diode array.

3. The structure according to claim 1, characterized in that: The resin-based wave-transmitting material is selected from quartz cloth / epoxy resin prepreg or quartz cloth / cyanate resin prepreg.

4. The structure according to claim 1, characterized in that The wave-transmitting foam material is an epoxy foam film.

5. The structure according to claim 1, characterized in that: The printed circuit dielectric plate material is a polytetrafluoroethylene plate.

6. The structure according to any one of claims 1 to 5, characterized in that The thickness of the front protective layer (1) and the back protective layer (8) are both 0.1 mm to 0.5 mm, the relative dielectric constants are both 2.5 to 3.5, and the loss tangent values ​​are both less than or equal to 0.

015.

7. The structure according to claim 6, characterized in that The thickness of the front buffer layer (2) and the back buffer layer (7) are both 0.3 mm to 1.5 mm.

8. An aircraft, comprising the active electromagnetic functional structure according to any one of claims 1 to 7.

9. A method for manufacturing an active electromagnetic functional structure, characterized in that: The method comprises: S1, using a printed circuit board process to prepare a substrate layer and a functional layer on the front side and a feed layer on the back side, wherein the substrate layer is a printed circuit dielectric board material, the functional layer is a metal periodic array pattern, and the feed layer is a metal series and / or parallel line pattern; S2, welding components on the functional layer; S3, cutting a front epoxy foam film used as a front buffer layer and a back epoxy foam film used as a back buffer layer according to the shape of the active electromagnetic functional structure, and cutting a thickness of the front epoxy foam film according to the height and foaming ratio of the electronic components; S4, in an operating environment with a temperature of 25±5°C and a relative humidity of ≤65%, the front epoxy foam film is laid on the surface of the component, and the back epoxy foam film is laid on the surface of the feed layer, and heated with hot air at a temperature not higher than 70°C to remove bubbles and adhere the film; S5, placing the active electromagnetic functional structure with the adhesive film attached in S4 flat in the curing equipment, with a curing pressure of 0.3±0.02MPa, heating from room temperature at a heating rate of 1-2°C / min, and curing according to a stage curing process of 90°C / 2h. After the curing is completed, the heat source is turned off, and the temperature is naturally lowered to below 40°C to release the pressure; S6, laying quartz cloth / epoxy resin prepreg with a thickness of 0.2 mm on the mold, placing the active electromagnetic functional structure obtained in S5 into the mold, laying quartz cloth / epoxy resin prepreg with a thickness of 0.2 mm on it, curing by heating and pressurizing, demolding and machining to obtain the final active electromagnetic functional structure.

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