High-precision helical antenna for spacecraft, preparation method of high-precision helical antenna and spacecraft

Abstract

The invention relates to the technical field of aerospace, and discloses a high-precision helical antenna for a spacecraft, a preparation method of the high-precision helical antenna and the spacecraft. The helical antenna comprises a base body made of a special engineering plastic material, and a metal coating spirally embedded on the outer surface of the base body, the number of the metal coating is at least one, and the metal coating comprises a copper coating, a nickel alloy coating and a gold or silver coating. By means of the process, the high-precision spiral metal conductive antenna with the metal coating and the base body integrated can be prepared on the surface of the special engineering plastic base body such as PI and PEEK. The metal coating on the surface of the spiral antenna is good in bonding strength and deformation resistance, the spiral metal coating is high in shape and position precision, the coating is free of abnormity in the high-temperature environment of-196 DEG C to + 150 DEG C or 260 DEG C, overall deformation is uniform and good in the high-temperature and low-temperature environment, good space environment stability is achieved, and the spiral antenna is a high-stability spiral antenna suitable for being applied to the space environment.

Description

Technical Field

[0001] The present application relates to the field of aerospace technology, and in particular to a high-precision helical antenna for a spacecraft, a preparation method thereof, and a spacecraft. Background Art

[0002] When working in outer space, spacecraft must withstand long-term alternating heating and cooling from the sun, planets, and low-temperature heat sinks in space. The temperature can vary by up to ±200°C. The communication antennas currently used in spacecraft need to be able to withstand such harsh high and low temperature changes without significant dimensional deformation, otherwise it will cause performance changes and lead to product failure.

[0003] Helical antennas are a type of communication antenna commonly used in the aerospace field. When preparing this type of traditional helical antenna, special engineering materials such as PI are usually used to prepare a circular base. Based on the generally smooth and dense surface characteristics of special engineering materials, the existing method uses a metal foil of a specific width and thickness, which is bonded to the circular base with organic glue. This antenna preparation method is relatively simple, but there are many problems in making high-precision helical antennas:

[0004] (1) The method of applying organic glue to the bottom of the metal foil is difficult to control the accuracy of the spiral line. It mainly relies on manual visual pasting and correction, and the position accuracy control is relatively poor.

[0005] (2) When the organic glue is applied to the bottom of the metal foil, the thickness of the organic glue varies, resulting in large differences in the distance between the spiral line and the center of the circle after pasting.

[0006] (3) The preparation process of the helical antenna requires repeated precise measurements and corrections to meet the design index requirements, which is time-consuming and labor-intensive.

[0007] (4) After the organic glue of the spiral antenna is applied to the surface of the PI and PEEK substrates, there may be a risk of debonding after experiencing harsh high and low temperature environments, causing the metal layer of the antenna to deform, affecting the accuracy of the antenna or even causing it to fail.

[0008] In view of the problems existing in the preparation process of traditional helical antennas and the risk of failure when used in space environments, there is an urgent need for a new high-precision helical antenna with an integrated metal conductive layer based on special engineering plastics such as PI. Summary of the invention

[0009] In view of this, the purpose of the present application is to provide a high-precision helical antenna for spacecraft and a preparation method thereof, so that the helical antenna has a high configuration accuracy, the metal plating on the surface of the helical antenna has high bonding strength and anti-deformation performance, and has resistance to high and low temperature thermal cycles, vacuum thermal cycles and other space environment performance;

[0010] Another object of the present application is to provide a spacecraft based on the above helical antenna.

[0011] In order to solve the above-mentioned technical problems / achieve the above-mentioned purposes or at least partially solve the above-mentioned technical problems / achieve the above-mentioned purposes, as the first aspect of the present application, a high-precision helical antenna for spacecraft is provided, comprising a substrate made of special engineering plastic material, and a metal coating spirally embedded on the outer surface of the substrate; the number of the metal coating is at least 1, including a copper coating, a nickel alloy coating, and a gold or silver coating.

[0012] Optionally, the metal plating layers are gold or silver plating layers, nickel alloy plating layers and copper plating layers from the outside to the inside.

[0013] Further optionally, the metal plating layer has a thickness of 10 to 50 μm and a width of at least 0.5 mm.

[0014] As a second aspect of the present application, a method for preparing the helical antenna described in the present application is provided, comprising:

[0015] S1. Process the special engineering plastics according to the size requirements to produce the base structure of the helical antenna;

[0016] S2. Protecting other substrate structural areas outside the metal coating area after processing, and then performing surface roughening treatment on the entire metal coating area;

[0017] S3. The metal coating region is activated by a mixed solution of palladium chloride and hydrochloric acid;

[0018] S4. The metal coating area is subjected to reduction treatment using a sodium hypophosphite solution;

[0019] S5. Chemical copper plating and electroplating of copper are performed on the metal coating area;

[0020] S6. Electroless nickel plating is performed on the metal coating region using an alkaline low stress electroless nickel plating solution;

[0021] S7. Electroplating the metal coating region with gold or silver;

[0022] S8. The metal-plated substrate is cleaned and baked, and then the periphery of the metal-plated area is processed to meet the size requirements.

[0023] Optionally, the surface roughening treatment includes sandblasting.

[0024] Optionally, the chemical copper plating is performed using the following chemical copper plating solution:

[0025]

[0026] Optionally, the copper electroplating is performed using the following copper electroplating solution:

[0027]

[0028] Optionally, the alkaline low stress chemical nickel plating solution comprises:

[0029]

[0030]

[0031] Optionally, the electroplating gold is performed using the following electroplating gold solution:

[0032]

[0033] As a third aspect of the present application, a spacecraft is provided, which is provided with the helical antenna described in the present application or the helical antenna prepared by the preparation method described in the present application.

[0034] The process of this application can prepare a high-precision spiral metal conductive antenna with a metal coating and a substrate integrated on the surface of a special engineering plastic substrate such as PI and PEEK. The line width accuracy of the spiral antenna can be controlled within the range of ±0.08mm, the thickness of the metal coating can be controlled within the range of 10 to 50μm, the thickness uniformity can be controlled within the range of ±3μm, the coating includes a good conductive metal layer such as copper, nickel alloy and gold (or silver), the coating resistance is less than 0.5mΩ, and the distance from the entire area of ​​the metal coating to the central axis of the substrate can be controlled within the range of ±0.03mm. The metal coating on the surface of the antenna has good bonding strength and deformation resistance, the spiral metal coating has high shape and position accuracy, the coating has no abnormalities in a high temperature environment of -196℃ to +150℃, or 260℃, the overall deformation is uniform and good in high and low temperature environments, and it has good space environment stability. It is a high-stability spiral antenna suitable for space environment applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application.

[0036] Figure 1 The figure shows a process flow chart of the preparation of the helical antenna of the present application;

[0037] Figure 2 The figure shows a real sample of the helical antenna of the present application; the left and right figures respectively show samples with different metal plating settings;

[0038] Figure 3 Shown is an example diagram of the video detection method for the width of the metal coating of the spiral antenna of the present application. DETAILED DESCRIPTION

[0039] The present application discloses a high-precision helical antenna for spacecraft, a method for preparing the same, and a spacecraft. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve the same. It is particularly important to point out that all similar substitutions and modifications are obvious to those skilled in the art, and they are all deemed to be included in this application. The products, processes, and applications described in this application have been described through preferred embodiments. Relevant personnel can obviously modify or appropriately change and combine the processes and applications described in this article without departing from the content, spirit, and scope of this application to implement and apply the technology of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0040] It should be noted that, in this article, if relational terms such as "first" and "second", "step 1" and "step 2", and "(1)" and "(2)" appear, they are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements. At the same time, the embodiments in this application and the features in the embodiments may be combined with each other without conflict.

[0041] In view of the shortcomings of insufficient manufacturing precision and low quality reliability of the manufacturing process of the current metal foil adhesive wrapped helical antenna, the present application provides a new high-precision helical antenna with an integrated metal conductive layer (metal plating) based on special engineering plastics such as PI. In the first aspect of the present application, a spacecraft high-precision helical antenna is provided, comprising a substrate made of special engineering plastic material, and a metal plating spirally embedded on the outer surface of the substrate; the number of the metal plating is at least 1, including a copper plating, a nickel alloy plating, and a gold or silver plating.

[0042] In certain embodiments of the present application, the metal coating is gold or silver coating, nickel alloy coating and copper coating from the outside to the inside, and each metal layer is superimposed layer by layer. Plating the copper coating on the surface of the substrate first can improve the bonding strength and conductivity between the coating and the substrate. The copper coating is beneficial in conductivity and the cost is relatively low. The use of other coatings will cause the bonding strength between the coating and the substrate to deteriorate, and the coating may be detached. The middle layer is plated with nickel coating to improve the corrosion resistance and conductivity of the coating; the outermost layer is plated with gold coating or silver coating to increase the service life of the coating, ensure the long life of the coating appearance, and also improve the bonding strength. Among them, the thickness of the copper coating is determined according to the actual demand design, the thickness of the nickel alloy coating is generally 1 to 5 μm, the thickness of the gold coating is generally 1 to 2 μm, and the thickness of the silver coating is generally 7 to 12 μm.

[0043] In certain embodiments of the present application, one end of the spiral metal coating may extend to the top of the substrate, and the other end may extend to the bottom of the substrate; when there are multiple spiral metal coatings, the rise angle of each metal coating remains the same, that is, when unfolded into a plane, the metal coatings are parallel to each other.

[0044] In certain embodiments of the present application, the substrate is generally columnar, such as cylindrical, which is more conducive to the setting of the metal coating; the thickness of the metal coating is 10 to 50 μm, the width is at least 0.5 mm, and the general width is 0.5 to 20 mm. It can also be processed to more than 200 mm according to actual needs. Usually, the width and thickness of the coating are set based on the simulation of the performance of the helical antenna. The width and thickness determine the conductivity and electromagnetic properties of the helical antenna, thereby determining the electrical properties of the antenna. In actual production, it is processed according to the design requirements. The smaller the error between the thickness and width obtained during production and the design requirements, the more accurate the performance of the antenna, the higher the precision, and the more it meets the design indicators, that is, the smaller the error.

[0045] In certain embodiments of the present application, the helical antenna may also be provided with a flange area on the base according to actual circumstances to facilitate connection with other components.

[0046] In certain embodiments of the present application, the special engineering plastics include but are not limited to PI (polyimide) and PEEK (polyetheretherketone).

[0047] In the second aspect of the present application, a method for preparing the spiral antenna is provided, which adopts a special engineering plastic substrate + a surface high-bonding strength conductive metal coating preparation technology + a secondary high-precision processing technology to prepare an integrated high-precision spiral antenna. Through the secondary high-precision processing control technology, the size of the metal conductive coating of the spiral complex structure antenna can be controlled with high precision. When preparing the antenna, firstly, a high-bonding strength metal coating is prepared on the surface of materials such as PI and PEEK, and then the metal coating of the non-spiral metal coating area of ​​the circumferential surface of the antenna is removed by high-precision processing technology, so that the metal layer size accuracy and spiral accuracy of the spiral antenna can be guaranteed by using a high-precision machine tool, thereby preparing a high-precision spiral antenna with an integrated metal conductive layer based on special engineering plastics such as PI.

[0048] The preparation method described in this application specifically includes:

[0049] S1. Process the special engineering plastics according to the size requirements to produce the base structure of the helical antenna;

[0050] S2. Protecting other substrate structural areas outside the metal coating area after processing, and then performing surface roughening treatment on the entire metal coating area;

[0051] S3. The metal coating region is activated by a mixed solution of palladium chloride and hydrochloric acid;

[0052] S4. The metal coating area is reduced using a sodium hypophosphite solution;

[0053] S5. Chemical copper plating and electroplating of copper are performed on the metal coating area;

[0054] S6. Electroless nickel plating is performed on the metal coating region using an alkaline low stress electroless nickel plating solution;

[0055] S7. Electroplating the metal coating region with gold or silver;

[0056] S8. The metal-plated substrate is cleaned and baked, and then the periphery of the metal-plated area is processed to meet the size requirements.

[0057] In certain embodiments of the present application, in step S1, a special engineering plastic can be processed by a machine tool to produce a circular deep cavity area in the spiral antenna area, and then a corresponding circular metal tooling is designed according to the size of the processed circular deep cavity, the size of which is slightly smaller than the diameter of the circular deep cavity, and then the circular metal tooling is inserted into the processed circular deep cavity of the spiral antenna, and after the fit is tight and there is no movement, a four-axis or higher machine tool is used to process the material to produce the product's outer dimensions; wherein the circular metal tooling can better fix the workpiece, facilitate subsequent machine tool processing, and prevent the workpiece from deforming, establish a benchmark for subsequent secondary processing, and avoid large deformation of the spiral antenna substrate after processing, resulting in poor accuracy of the spiral antenna. The use of the circular metal tooling can control the benchmark change within 0.1μm. At the same time, the outer dimension accuracy of the metal plating area of ​​the spiral antenna is controlled within the range of ±0.03mm, and the size of the flange area meets the actual requirements.

[0058] In certain embodiments of the present application, the surface roughening treatment includes sandblasting, which can form a certain degree of roughness on the substrate surface and improve the bonding strength of the subsequent coating. The abrasive used in the sandblasting treatment has a particle size of 100-150 mesh and a pressure of 0.05MPa-0.2Mpa.

[0059] In certain embodiments of the present application, in step S3, a mixed solution of palladium chloride and hydrochloric acid is used to activate the special engineering plastic; non-metallic materials cannot be directly electroplated during electroplating, and activation treatment must be performed first to obtain activation points on the surface of the special engineering plastic substrate, and then the metal is deposited on the activation points; a mixed solution of palladium chloride and hydrochloric acid can obtain stable activation points on the substrate surface, resulting in stable bonding force of the coating and not easy to fall off. ; wherein the concentration of palladium chloride in the mixed solution is 0.2g / L~1.0g / L, and the concentration of hydrochloric acid is 1ml / L~5ml / L; the activation treatment is soaked at room temperature for 1min~5min.

[0060] In certain embodiments of the present application, in step S4, a sodium hypophosphite solution is used for reduction treatment; wherein the concentration of the sodium hypophosphite is 15 g / L to 25 g / L, and the reduction treatment is performed by soaking at room temperature for 1 min to 5 min.

[0061] In certain embodiments of the present application, in step S5, copper is first plated with a chemical copper plating solution, and then electroplated with an electrolytic copper plating solution. Due to the generally smooth and dense surface characteristics of special engineering materials, even after roughening, direct electroplating of copper may not be effective. Therefore, it is necessary to first perform chemical copper plating to initially stabilize the coating, and then further use an electroplating copper process to stabilize the entire copper coating.

[0062] The chemical copper plating adopts the following chemical copper plating solution for copper plating. Compared with the conventional commercial chemical copper plating solution, the present application adds several additives to improve the bonding strength:

[0063]

[0064] The pH value of the chemical copper plating solution is 12-13, and the copper plating is carried out at a temperature of 25° C. to 35° C. for 1 hour to 1.5 hours. The process requires stirring with compressed air.

[0065] In some other embodiments of the present application, the copper electroplating is performed using the following copper electroplating solution:

[0066]

[0067] The parameters in the copper electroplating process can be referred to as follows:

[0068]

[0069] In certain embodiments of the present application, in step S6, the alkaline low stress chemical nickel plating solution comprises:

[0070]

[0071] The pH value of the chemical nickel plating solution is 9 to 11, and the nickel plating time is 20 to 30 minutes. The cracking of the coating is often caused by the inconsistency of the temperature deformation between the substrate and the chemical nickel plating layer. The use of alkaline low-stress chemical nickel plating can effectively reduce the internal stress of the metal coating, and the reduction of internal stress is conducive to preventing deformation caused by stress release at subsequent high and low temperatures and cracking of the coating.

[0072] 2) The biggest problem with nickel electroplating is that the thickness of the coating will be affected by the uneven distribution of electric lines during deposition, resulting in greater unevenness in the thickness of the coating, which in turn causes greater unevenness in the thickness of the metal layer, affecting the accuracy of the antenna's electrical performance.

[0073] In certain embodiments of the present application, in step S7, the electroplating gold is performed using the following electroplating gold solution:

[0074]

[0075] The parameters in the gold electroplating process can be referred to as follows:

[0076]

[0077] In some embodiments of the present application, the baking temperature in step S8 is 200°C to 220°C, and the time is 110min to 130min. Too high or too low baking temperature may lead to poor coating bonding strength, and the coating may fall off in subsequent high and low temperature environments.

[0078] In some other embodiments of the present application, in step S8, the periphery of the metal-plated area is processed to meet the size requirements, and the circular metal tooling prepared in the aforementioned S1 can continue to be loaded into the circular deep cavity area, and then the material is processed using a four-axis or above machine tool. During processing, a spherical cutter is first used to mill off the metal coating in the non-metallic coating area on the surface that is 1 mm away from the metal-plated area, and the milling depth is 0.02mm to 0.04mm on a single side; then, the processing is continued, and a 1mm milling cutter is used to mill off the remaining metal coating in the non-metallic coating area on the surface, and the line width and height of the metal-plated area are controlled, and the milling depth is 0.02mm to 0.05mm on a single side; finally, burrs that may exist after milling are removed to complete the processing.

[0079] In the third aspect of the present application, after detection and testing, the thickness of the metal coating on the surface of the helical antenna described in the present application is between 10 and 50 μm, mainly composed of copper, nickel (including nickel-phosphorus alloy) and gold (or silver) and other good conductive metal layers. The uniformity of the coating thickness can be controlled within the range of ±3 μm, the coating resistance is less than 0.5 mΩ, the metal coating width, the number of metal coating turns and the configuration can vary according to actual needs, the coating bonding strength can withstand -196°C to +150°C, does not fall off after 100 thermal cycles, does not fall off after high-temperature baking at 260°C, and the coating has excellent weldability; the above-mentioned properties can effectively avoid the aging of the adhesive layer caused by the conventional metal foil organic adhesive bonding method, the deterioration of the bonding strength at high and low temperatures, and even the quality problems of delamination, and have the advantages of high electrical performance consistency and strong quality stability.

[0080] Moreover, taking the most classic cylindrical spiral antenna as an example, the dimensional accuracy of the cylindrical substrate can be controlled within ±0.03mm, the width of the metal coating after secondary processing can be controlled within ±0.1mm, the position accuracy is controlled within ±0.1mm, and the conductive metal coating all falls within the cylindrical range of ±0.03mm from the center of the circle; high-precision dimensional control can effectively improve the stability of the electromagnetic performance of the spiral antenna, and can effectively avoid the dimensional uncontrollability caused by conventional metal foil organic adhesive bonding, and the shortcomings of repeated testing and repair.

[0081] Based on the above-mentioned various beneficial effects, the present application provides a spacecraft, which is provided with the helical antenna described in the present application or the helical antenna prepared by the preparation method described in the present application.

[0082] The following is a further description of a high-precision helical antenna for spacecraft, a method for preparing the same, and a spacecraft provided in this application.

[0083] Embodiment 1:

[0084] 1) Purchase qualified PI with a diameter of 45 and a length of 300;

[0085] 2) The PI material obtained in step 1) is processed by machine tools. During processing, firstly, according to the requirements of the drawing, a circular deep cavity area of ​​the product spiral antenna area is processed. The inner diameter of the area is 26 and the depth is 270. The inner diameter after processing is within the range of 26±0.1mm. The inner diameter 26 is measured. A circular tooling with an outer diameter of 26 is processed by aluminum alloy. The diameter of the circular deep cavity area is about 0.05mm~0.1mm smaller. Then the tooling is inserted into the circular deep cavity processed by the spiral antenna, and it fits tightly without movement.

[0086] 3) The PI material processed in step 2) is processed by a machine tool with four axes or above. During processing, the outer dimensions of the product are processed according to the requirements of the drawing. The outer dimensions of the conductive coating area of ​​the helical antenna are processed to 30, and the dimensional accuracy is controlled within the range of ±0.03mm. The dimensions of the flange area meet the requirements of the drawing after processing;

[0087] 4) Check the dimensions of the product after processing in step 3) to ensure that it meets the requirements of the drawing;

[0088] 5) Cleaning the surface of the qualified products in step 4) with anhydrous ethanol;

[0089] 6) Protect the qualified products in step 5) with protective paint or tape, protect the inner cavity and flange areas of the processed products, and only expose the conductive coating area of ​​the helical antenna;

[0090] 7) The product after protection in step 6) is subjected to sandblasting treatment with the following parameters:

[0091] Pressure 0.01MPa

[0092] Particle size 100 mesh

[0093] 8) The product after sandblasting in step 7) is cleaned by ultrasonic wave to remove sand particles that may remain on the surface;

[0094] 9) The product obtained in step 8) is activated, and the formula and operating conditions are as follows:

[0095]

[0096] After activation is complete, the product is removed from the solution;

[0097] 10) The surface of the product obtained in step 9) is subjected to reduction treatment, and the formula and operating conditions are as follows: Sodium hypophosphite 20g / L

[0098] Solution temperature Room temperature

[0099] Duration: 3min

[0100] 11) washing the surface of the product obtained in step 10) with water for 30 seconds;

[0101] 12) The product obtained in step 11) is subjected to chemical copper plating, and the formula and operating conditions are as follows:

[0102] After plating is completed, the product is taken out of the solution and cleaned with running pure water;

[0103] 13) The product obtained in step 12) is subjected to copper electroplating treatment, and the formula and operating conditions are as follows:

[0104] The brightener is a mixture of sodium polydisulfide propanesulfonate and sodium polydimethylamide sulfonate; during plating, the electroplating time can be adjusted according to the thickness requirement of the electroplated copper layer. After plating, the product is taken out of the solution and rinsed with running pure water;

[0105] 14) The product obtained in step 13) is subjected to alkaline low-stress chemical nickel plating treatment, and the formula and operating conditions are as follows:

[0106]

[0107] After plating is completed, the product is taken out of the solution and rinsed with running pure water;

[0108] 15) The surface of the product obtained in step 14) is gold plated, and the solution formula and operating conditions of the gold plating are as follows:

[0109]

[0110] After plating is completed, the product is taken out of the solution and rinsed with running pure water;

[0111] 16) removing the protective paint or protective tape on the surface of the product obtained in step 15);

[0112] 17) The product obtained in step 16) is subjected to baking treatment, and the baking operation conditions are as follows:

[0113] Temperature 200℃

[0114] Time: 120 minutes

[0115] 18) Processing the product obtained in step 17) by inserting the tooling with an outer diameter of 26 used in the previous processing into the circular deep cavity area with an inner diameter of 26, and then processing the material using a machine tool with four axes or more;

[0116] 19) The product obtained in step 18) is processed, and the area with an outer diameter of 30 is processed. The processing path is set according to the requirements of the spiral line (spiral metal coating). During processing, a spherical cutter is first used to mill off the non-spiral area of ​​the surface, and the metal coating in the area 1mm away from the spiral line is milled. The milling depth is 0.04mm on one side;

[0117] 20) The product obtained in step 19) is further processed, using a 1 mm milling cutter to mill off the remaining metal coating in the non-helical area of ​​the surface, and the line width and height of the spiral area are controlled, and the milling depth is 0.04 mm on one side;

[0118] 21) removing burrs and the like that may exist after milling from the product obtained in step 20) to obtain a high-precision helical antenna with an integrated metal conductive layer based on special engineering plastics such as PI and PEEK;

[0119] 22) Inspect the product obtained in step 21) to confirm compliance.

[0120] The schematic diagram of the preparation process will be Figure 1 The actual picture of the prepared helical antenna sample is shown in Figure 2 .

[0121] Embodiment 2:

[0122] 1. Helical antenna structure accuracy detection

[0123] (1) Detection method

[0124] The diameter of the substrate of the helical antenna can be directly measured by a micrometer or a vernier caliper to obtain the size of the substrate. The accuracy is based on the different accuracies of the micrometer and the vernier caliper, and the error accuracy of 0.001mm and 0.02mm is obtained.

[0125] The height difference of the metal coating of the spiral antenna, that is, the height of the spiral metal coating from the central axis of the substrate, can be directly measured by a micrometer or a vernier caliper to obtain the size of the substrate. The accuracy is based on the different accuracies of the micrometer and the vernier caliper, and the measurement error accuracy is 0.001mm and 0.02mm. The three-coordinate system can also be used for precise measurement to obtain a measurement error accuracy of 0.001mm.

[0126] The coating thickness of the helical antenna can be measured by using the same slot test piece during surface treatment, and then preparing metallographic samples for the same slot test piece to test the coating thickness. It is also possible to use a micrometer or three-coordinate measuring machine to detect the dimensional accuracy of the substrate before electroplating, and record the detection position. After electroplating, the size of the position can be detected again. The coating thickness can be obtained through the change in size. By detecting the coating thickness in different areas, the uniformity of the thickness and the dimensional accuracy range can be obtained.

[0127] The width of the metal coating of the helical antenna can be detected by video detection method. The plane width of the coating can then be detected by video detection method, and then the actual coating width can be calculated according to the circumference of the substrate. Figure 3 Example.

[0128] The resistance of the coating can be directly detected by a microohmmeter, and the accuracy of the microohmmeter can reach 0.01mΩ.

[0129] (2) Test results

[0130] Through testing, the metal spiral antenna can obtain the following results in Table 1:

[0131] Table 1 Helical antenna structure accuracy test results

[0132] Serial number Design requirements Measured accuracy Error Description Measuring equipment or method Substrate outer diameter 26±0.1mm 26.02~26.05mm Within ±0.1mm Vernier caliper Spiral outer diameter 26±0.1mm 26.023~26.051mm Within ±0.03mm Micrometer Coating thickness 28um~40um 28um~32um Within ±3um Metallography Coating width 2±0.1mm 1.95~1.97mm Within ±0.1mm Video detector resistance ≤5mΩ 0.34~0.38mΩ ±0.5mΩ Microohmmeter

[0133] It can be directly seen from the test results in Table 1 above that the helical antenna prepared according to the method of the present application has a very small error with the design requirements, achieves extremely high structural accuracy, and ensures the working performance of the helical antenna.

[0134] 2. Testing of helical antenna's space environment resistance performance

[0135] (1) Detection method

[0136] High and low temperature performance test: put the product in an oven, set the oven temperature to 150℃, and the oven temperature control accuracy uniformity to ±5℃. After reaching 150℃, keep it warm for 20 minutes, then open the oven, take out the product, and immerse it directly in liquid nitrogen (-196℃) for 5 minutes. This is one cycle. Then take it out and put it in a 150℃ oven, keep it warm for 20 minutes, and then put it in liquid nitrogen for 5 minutes. Repeat 100 times, then take it out and put it at room temperature, and use a 10x magnifying glass to detect the bonding strength of the coating.

[0137] High temperature performance test: put the product into the oven, set the oven temperature to 260℃, the oven temperature control accuracy uniformity is ±5℃, keep warm for 60 minutes after reaching 260℃, turn off the oven after the time is up, turn on the heat dissipation in the oven, take out the sample after the heat dissipates to room temperature, and use a 10x magnifying glass to detect the bonding strength of the coating.

[0138] (2) Test results

[0139] After environmental testing, the experimental results are as follows Table 2:

[0140] Table 2

[0141]

[0142] It can be seen from the data test results in Table 2 above that the helical antenna of the present application still maintains a high structural stability after experiencing severe high and low temperature environments, and will not have the quality problems of aging of the adhesive layer caused by conventional metal foil organic adhesive bonding methods, deterioration of bonding strength under high and low temperatures, or even delamination. It has the advantages of high electrical performance consistency and strong quality stability.

[0143] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A high-precision helical antenna for spacecraft, characterized in that: It comprises a substrate made of special engineering plastic material, and a metal plating layer spirally embedded on the outer surface of the substrate; the number of the metal plating layer is at least one, including a copper plating layer, a nickel alloy plating layer, and a gold or silver plating layer.

2. The helical antenna according to claim 1, characterized in that The metal plating layers are gold or silver plating layers, nickel alloy plating layers and copper plating layers in order from the outside to the inside.

3. The helical antenna according to claim 1 or 3, characterized in that: The metal plating layer has a thickness of 10 to 50 μm and a width of at least 0.5 mm.

4. The method for preparing the helical antenna according to claim 1, characterized in that: include: S1. Process the special engineering plastics according to the size requirements to produce the base structure of the helical antenna; S2. Protecting other substrate structural areas outside the metal coating area after processing, and then performing surface roughening treatment on the entire metal coating area; S3. The metal coating region is activated by a mixed solution of palladium chloride and hydrochloric acid; S4. The metal coating area is reduced using a sodium hypophosphite solution; S5. Chemical copper plating and electroplating of copper are performed on the metal coating area; S6. Electroless nickel plating is performed on the metal coating region using an alkaline low stress electroless nickel plating solution; S7. Electroplating the metal coating region with gold or silver; S8. The metal-plated substrate is cleaned and baked, and then the periphery of the metal-plated area is processed to meet the size requirements.

5. The preparation method according to claim 4, characterized in that: The surface roughening treatment includes sandblasting.

6. The preparation method according to claim 4, characterized in that: The chemical copper plating adopts the following chemical copper plating solution for copper plating:

7. The preparation method according to claim 4, characterized in that: The copper electroplating is carried out using the following copper electroplating solution:

8. The preparation method according to claim 4, characterized in that: The alkaline low stress chemical nickel plating solution comprises:

9. The preparation method according to claim 4, characterized in that: The electroplating gold is plated using the following electroplating gold solution:

10. A spacecraft, characterized in that: It is provided with the helical antenna described in claims 1-3 or the helical antenna prepared by the preparation method described in any one of claims 4-9.

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