Electromagnetic protection component preparation method based on energy selective surface technology

Abstract

The invention relates to an electromagnetic protection component preparation method based on an energy selective surface technology. The method comprises the steps that S1, a protection component design model is split into protection component design models, protection components are prepared in a fragmented mode according to the protection component design models, and a positioning identifier is machined on each protection component; s2, a conformal tool with the same appearance as the protected component is machined, and positioning points are machined on the surface of the conformal tool; s3, the conformal tool is fixedly connected with a rotating shaft of the five-axis rotating table; s4, the protection components are transferred to a conformal tool to be spliced and temporarily fixed, and positioning points on the surface of the conformal tool and positioning marks on the protection components are used for position alignment; and S5, the conformal tool is driven to rotate through the five-axis rotating table, the parts, needing to be connected, of the protection components are moved to the position below a laser ball spraying soft soldering device, electronic circuits on the protection components are welded in a laser ball spraying mode, and the electromagnetic protection component is obtained.

Description

Technical Field

[0001] The present invention relates to a preparation method of an electromagnetic protection component based on energy selective surface technology, belonging to the field of manufacturing electromagnetic protection components. Background Art

[0002] Strong electromagnetic protection of the front door of electronic information equipment in the space environment is a key technology for current space attack and defense. At present, researchers mostly use protective cover structures with power limiting or frequency selection for electromagnetic protection of ground equipment. For information transceiver equipment of spacecraft in the space environment, while meeting the strong electromagnetic protection efficiency, it is necessary to achieve low loss of the original communication function of the equipment and conformal manufacturing of large-size curved surface protection components.

[0003] In the application of front door electromagnetic protection, it is necessary to selectively adopt different transmission responses according to the intensity of the incident signal to achieve the transmission of normal intensity signals and the shielding of strong electromagnetic signals. The Energy Selective Surface (ESS) is based on the principle of field-induced impedance, and adaptively performs transmission impedance transformation according to the signal intensity, so as to realize signal filtering in the energy domain.

[0004] The electromagnetic protection component based on energy selective surface technology is a flexible thin-film circuit component composed of a polyimide film dielectric layer, refined metal pattern lines (periodic array), protection devices (PIN diodes), space environment-resistant coatings, etc., and can be conformally attached to the protected object on the surface. According to the strong electromagnetic protection application requirements of spacecraft information transceiver equipment, the protection component is a component composed of single protection elements edited, copied, and integrated according to certain rules, and can meet the conformal protection requirements of large-size and special-shaped curved surface information transceiver equipment.

[0005] Due to the limitations of the spacecraft's shape size, manufacturing process, and precision requirements, etc., it is impossible to complete the manufacturing of large-size protection components at one time. It is necessary to decompose the component model into curved surfaces according to the structural characteristics of the protected object, and form a series of protection elements by combining the manufacturing process and protection efficiency. The size of a single protection element is generally within 500mm * 500mm.

[0006] The manufacturing process of the protection element includes: the manufacturing technology of the internal metal pattern of the curved surface element, the welding and encapsulation process of the element, etc. The manufactured elements need to be spliced to achieve electrical interconnection between the components. How to splice and ensure the electromagnetic performance of the component after splicing is the key to achieving high protection effect. Summary of the Invention

[0007] The technical problem solved by the present invention is: overcoming the deficiencies of the prior art, providing a preparation method of an electromagnetic protection component based on energy selective surface technology, and solving the problems of over-large size and inability to be integrally manufactured of large-size protection components.

[0008] The solution of the present invention to solve the technical problem is: a preparation method of an electromagnetic protection component based on the energy selective surface technology, the method comprising the following steps:

[0009] S1. Split the protection component design model into protection element design models, prepare the protection elements by slicing according to the protection element design models, and process positioning marks on each protection element;

[0010] S2. Process a conformal tooling with the same shape as the protected component, and process positioning points on the surface of the conformal tooling;

[0011] S3. Fix the conformal tooling fixedly connected to the rotation axis of the five-axis rotating table;

[0012] S4. Transfer the protection elements to the conformal tooling for splicing and temporary fixing, and align the positions by using the positioning points on the surface of the conformal tooling and the positioning marks on the protection elements;

[0013] S5. Drive the conformal tooling to rotate through the five-axis rotating table, move the parts to be connected between the protection elements below the laser spray ball soft soldering device, and solder the electronic circuits on the protection elements by means of laser spray ball to obtain the electromagnetic protection component.

[0014] Preferably, the preparation method of the electromagnetic protection component based on the energy selective surface technology further comprises the following steps:

[0015] S6. Check the morphology of the solder joints after the protection components are connected, check whether the solder balls are fully wetted and spread on the parts to be connected, and perform supplementary soldering on the parts that are not successfully connected.

[0016] Preferably, the protection element is prepared by the following method:

[0017] Process the protection element substrate by using a polyimide film;

[0018] Coat the protection element substrate with a catalytic adhesive;

[0019] Use the nanosecond laser method to metallize the catalytic adhesive coated on the surface of the polyimide flexible substrate to obtain the electronic circuit of the protection element;

[0020] Thicken the electronic circuit of the protection element by means of electroless copper plating process;

[0021] Weld the protection devices on the electronic circuit of the protection element to complete the processing of the protection element.

[0022] Preferably, the thickness of the electronic circuit of the protection element is not less than 20 um.

[0023] Preferably, the design model of the protective component is split according to the maximum processing capacity of the protective component processing equipment and the principle of minimizing the splicing of the protective components.

[0024] Preferably, the conformal tooling of the component to be protected has the same shape as the component to be protected.

[0025] Preferably, the line spacing at the docking point after splicing the rectangular metallized lines between adjacent protective components is < 300um, and the upper and lower deviation is < 200um.

[0026] Preferably, the deviation of the surface positioning points of the conformal tooling from the positioning mark positions on the protective components is not less than 100um.

[0027] Preferably, balls with a diameter of 500μm or 300μm are selected for laser ball spraying welding.

[0028] The beneficial effects of the present invention compared with the prior art are as follows:

[0029] (1) The present invention adopts a method of splitting and splicing the conformal tooling, realizing high-precision processing of large-size electromagnetic protection components based on the energy selection surface technology. Compared with the existing overall inkjet printing method, the size of the manufacturable components is greatly improved. Compared with the traditional flexible film subtractive etching processing method, high-precision processing of special-shaped curved surfaces is realized;

[0030] (2) By setting positioning points on the conformal tooling and the protective component film, the present invention realizes high-precision splicing of different protective components;

[0031] (3) The present invention integrates a set of laser ball spraying and soldering device on a five-axis machine tool, and uses the five-axis machine tool to control the direction of the component in real time, so that the spray welding points can be directly opposite to the welding positions for welding, realizing high-precision connection of the metal line patterns of the large-size complex curved surface configuration protective components and ensuring the consistency of the large-area welding point morphology;

[0032] (4) The method of laser spraying adopted by the present invention can realize spray welding of heterogeneous interfaces. Compared with the existing technologies such as electric soldering irons and spot welding, it can realize long-distance large-area spray welding and improve the welding quality;

[0033] (5) The present invention realizes on-line detection of the interconnected welding points at the splicing positions by using the visual detection device carried on the five-axis machine tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is the protective component and the protective member in the embodiment of the present invention;

[0035] Figure 2 It is the laser spray welding equipment in the embodiment of the present invention. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with embodiments.

[0037] The present invention provides a method for preparing an electromagnetic protection component based on the technology of electromagnetic bandgap (EBG) surface. First, the protection component is divided into protection elements, and connections are required between the protection elements to ensure the electromagnetic protection efficiency of the component. Then, three-dimensional online splicing of the protection component is carried out based on a five-axis rotating table to achieve electrical interconnection between the elements. The specific content is as follows:

[0038] S1. Split the design model of the protection component into design models of protection elements, prepare the protection elements by slicing according to the design models of protection elements, and process positioning marks on each piece of protection element;

[0039] The protection component model is split according to the maximum processing capacity of the protection element processing equipment and the principle of minimum splicing of protection elements. The split protection elements are respectively processed for the curved protection element structure. The catalytic glue coated on the surface of the polyimide flexible substrate is activated by an ultrafast laser to obtain the graphic circuit of the protection element. The circuit is thickened by electroless copper plating, and the thickness is not less than 20 um. After the processing of the metallized circuit on the surface of the protection element is completed, the protection device is welded. All protection elements are processed according to this method.

[0040] The protection element is prepared by the following method:

[0041] The substrate of the protection element is processed with a polyimide film;

[0042] Catalytic glue is coated on the substrate of the protection element;

[0043] By using the nanosecond laser method, the catalytic glue coated on the surface of the polyimide flexible substrate is metallized to obtain the electronic circuit of the protection element. The position accuracy control between the graphic of the electronic circuit of the protection element and the curved substrate of the protection element is achieved by positioning the feature points through a high-precision vision recognition camera, and the height of the feature points is determined by laser altimetry, so as to realize the overall graphic positioning.

[0044] The electronic circuit of the protection element is thickened by electroless copper plating; the thickness of the electronic circuit of the protection element is not less than 20 um.

[0045] The protection device is welded on the electronic circuit of the protection element to complete the processing of the protection element.

[0046] At least three positioning point marks are arranged on each piece of protection element, and the positioning point marks are cross marks.

[0047] S2. Process a conformal tooling with the same shape as the protected component, and process positioning points on the surface of the conformal tooling;

[0048] The conformal tooling can be prepared from lightweight materials such as high-density foam, etc. The conformal tooling is processed according to the shape of the component to be protected, so that the conformal tooling of the component to be protected has the same shape as the outer shape of the component to be protected.

[0049] During the processing, at least three positioning point marks are arranged on the surface of the conformal tooling, and the positioning points are cross marks; the splicing route is determined according to the circuit connection relationship between different protection components. For Figure 1 For the reflective surface structure protection component shown, first fix the bottom circular component on the tooling, and then splice the trapezoidal protection components in sequence.

[0050] The position deviation between the positioning points on the surface of the conformal tooling and the positioning marks on the protection component is not less than 100um.

[0051] S3. Fix the conformal tooling fixedly connected to the rotating shaft of the five-axis rotary table;

[0052] The conformal tooling is processed with fixing holes and is fixedly connected to the moving platform of the five-axis machine tool through screws

[0053] S4. Transfer the protection components to the conformal tooling for splicing and temporary fixing, and use the positioning points on the surface of the conformal tooling and the positioning marks on the protection components to align the positions;

[0054] Attach the fabricated protection components to the corresponding positions of the conformal tooling according to the splicing sequence, and use the positioning point marks to achieve high-precision positioning of the protection components and the conformal tooling. After each protection component is spliced, it is temporarily fixed on the tooling with adhesives or adhesive tapes to ensure that the protection components do not displace during the movement of the machine tool. The line spacing of the docking points after splicing the rectangular metallized lines between adjacent protection components is <300um, and the up and down deviation is <200um.

[0055] S5. Drive the conformal tooling to rotate through the five-axis rotary table, move the parts that need to be connected between the protection components under the laser spray ball soldering device, and use the method of laser spray ball to weld the electronic circuits on the protection components to obtain the electromagnetic protection component.

[0056] Spray the positions that need to be connected with solder balls with a tin-lead composition of Sn63Pb37 with a diameter of 300-500μm to make the distance between the positions to be sprayed and the nozzle the same, and use the Figure 2 equipment shown for laser spray welding. During spray welding, the solder balls are heated by coaxial laser pulses to form molten droplets, and are sprayed onto the metallized pads under the action of nitrogen pressure (the pressure is between 0.4MPa and 0.6MPa). With the help of the temperature exceeding 500°C instantaneously and the physical impact, it quickly wets and spreads on the metallized lines to achieve in-situ metallurgical bonding at room temperature. Control the five-axis machine tool equipment to drive the protection component to rotate so that the normal direction of the curved surface of the position that needs to be connected on the protection component faces the laser nozzle.

[0057] Select balls with a diameter of 500 μm or 300 μm for laser ball jet soldering.

[0058] S6. Inspect the morphology of the solder joints after connecting the protective components to check whether the solder balls are sufficiently wetted and spread on the parts to be connected. For the parts that are not successfully connected, perform supplementary soldering.

[0059] Use the vision inspection device or microscope configured in the laser ball jet soldering device to inspect the morphology of the solder joints after connection. It is required that the ejected solder ball joints are evenly wetted between the metallized lines to be connected. For the cases where good connection is not achieved (the solder ball is only connected to one side of the metallized line), re-spray the ball for repair welding to ensure the connection reliability. Select balls with a diameter of 500 μm or 300 μm for repair welding according to the size of the spacing between the metallized lines at the unconnected part.

[0060] Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A preparation method of an electromagnetic protection component based on the energy selective surface technology, characterized in that It includes the following steps: S1. Split the design model of the protection component into design models of protection components. Prepare the protection components in slices according to the design models of protection components, and process positioning marks on each slice of the protection component; S2. Process a conformal tooling with the same shape as the component to be protected, and process positioning points on the surface of the conformal tooling; S3. Fix the conformal tooling to the rotating shaft of the five-axis rotating table; S4. Transfer the protection components to the conformal tooling for splicing and temporary fixation, and align the positions by using the positioning points on the surface of the conformal tooling and the positioning marks on the protection components; S5. Drive the conformal tooling to rotate through the five-axis rotating table, move the parts that need to be connected between the protection components under the laser ball spraying and soldering device, and weld the electronic circuits on the protection components by using the method of laser ball spraying to obtain an electromagnetic protection component.

2. The preparation method of an electromagnetic protection component based on the energy selective surface technology according to claim 1, characterized in that It also includes the following steps: S6. Check the morphology of the solder joints after the protection components are connected. Check whether the solder balls are fully wetted and spread on the parts to be connected. For the parts that are not successfully connected, perform supplementary soldering.

3. The preparation method of an electromagnetic protection component based on the energy selective surface technology according to claim 1, characterized in that, The protection component is prepared by the following method: Use a polyimide film to process the substrate of the protection component; Coat a catalytic adhesive on the substrate of the protection component; Use the nanosecond laser method to metallize the catalytic adhesive coated on the surface of the polyimide flexible substrate to obtain the electronic circuit of the protection element; Thicken the electronic circuit of the protection element by means of electroless copper plating process; Weld protection devices on the electronic circuit of the protection element to complete the processing of the protection component.

4. The preparation method of an electromagnetic protection component based on the energy selective surface technology according to claim 1, wherein, The thickness of the electronic circuit of the wire protection element is not less than 20 μm.

5. The preparation method of an electromagnetic protection component based on the energy selective surface technology according to claim 1, wherein The design model of the protection component is split according to the maximum processing capacity of the protection component processing equipment and the principle of the least splicing of the protection components.

6. The preparation method of an electromagnetic protection component based on the electromagnetic bandgap technology according to claim 1, wherein The conformal tooling of the component to be protected has the same shape as the component to be protected.

7. A preparation method of an electromagnetic protection component based on the energy selective surface technology according to claim 1, characterized in that, The line spacing of the butt joints of the rectangular metallized circuits between adjacent protection components after splicing is < 300 μm, and the upper and lower deviation is < 200 μm.

8. A preparation method of an electromagnetic protection component based on the energy selective surface technology according to claim 1, characterized in that The position deviation between the positioning points on the surface of the conformal tooling and the positioning marks on the protection component is not less than 100 μm.

9. The preparation method of an electromagnetic protection component based on the energy selective surface technology according to claim 1, wherein Select a ball with a diameter of 500 μm or 300 μm for laser ball spraying and soldering.

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