Signal connector and preparation method thereof

Abstract

The invention discloses a signal connector and a preparation method thereof, and the signal connector comprises a contact substrate which is provided with a micropore structure with a high length-width ratio; the Fe-Ga-Cu ternary eutectic nano-magnetic layer is arranged on the surface of the contact substrate and is used for generating mechanical vibration and generating an acoustic signal under the excitation of an external alternating magnetic field; and the noble metal plating layer is arranged on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetic layer and is used for ensuring the conductivity and contact reliability of signal transmission. According to the invention, non-destructive in-situ detection and accurate control of the thickness distribution of the noble metal layer in the micropore structure with a high length-width ratio are realized, the technical problem that the thickness of the noble metal layer in the micropore is not uniform and is difficult to detect in the traditional preparation process is solved, and the reliability and the service life of the signal connector are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of signal connector preparation and nondestructive testing, and in particular to a signal connector and a preparation method thereof. Background Art

[0002] Signal connectors are key components for signal transmission in electronic devices and are used to establish reliable electrical connections between different circuit boards or systems. Typical signal connectors are mainly composed of metal conductive contacts, insulator housings, and shielding structures. The metal conductive contacts are usually made of copper alloys and are directly responsible for the transmission of electrical signals. A precious metal layer is required on the surface to improve contact reliability and anti-oxidation performance. Blind holes and microchannel structures with high aspect ratios (depth is much greater than diameter) are often designed on the conductive contacts. These structures are used to provide elastic support, as locking points with plastic housings, or as signal modulation structures in certain designs. As communication equipment, computers, and other fields develop towards high frequency and high speed, signal connectors not only need to meet basic mechanical connection functions, but also need to provide excellent signal integrity and long-term reliability.

[0003] In the prior art, the preparation process of the signal connector includes the steps of contact molding, surface treatment, precious metal layer formation, insulator injection molding and assembly. During the formation of the precious metal layer, when the treatment liquid is immersed in the high aspect ratio blind hole or microchannel on the contact, due to physical factors such as uneven field distribution, ion concentration gradient and mass transfer limitation, the metal layer has obvious differences in spatial distribution: the layer is too thick at the hole mouth, the layer becomes thinner at the hole waist, and the layer at the bottom of the hole is extremely thin or even almost free of precious metal. This thickness non-uniformity will form a local high resistance area during the use of the connector, causing local overheating, accelerating electromigration, and in severe cases leading to contact failure. Traditional precious metal layer detection methods such as X-ray fluorescence analysis can only perform surface or shallow layer measurements and cannot detect the inside of deep holes; although the cross-section slicing method can observe the internal structure, it destroys the sample and cannot be used for production line detection; other non-destructive detection methods have insufficient resolution and it is difficult to accurately measure the distribution of precious metal layers in tiny structures. Therefore, how to accurately monitor and evaluate the thickness distribution of precious metal layers inside high aspect ratio blind holes and microchannels in real time without damaging the product has become a technical problem that needs to be solved urgently in the preparation process of signal connectors. Summary of the invention

[0004] The main purpose of the present invention is to solve the technical problems that the plating thickness of the microporous structure (blind holes and microchannels) of the metal conductive contacts in the existing signal connector preparation process is unevenly distributed and it is difficult to perform non-destructive three-dimensional in-situ detection.

[0005] A first aspect of the present invention provides a signal connector, comprising: A contact substrate, wherein the contact substrate is provided with a microporous structure; An Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer disposed on the surface of the contact substrate, the thickness of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer being 12-18 nm, the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer being used to generate mechanical vibrations and generate acoustic signals under the excitation of an external alternating magnetic field, and the frequency characteristics of the acoustic signals being displaced as the coating thickness changes; A noble metal coating disposed on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, the thickness of the noble metal coating being uniformly distributed along the axial and radial directions of the microporous structure, the noble metal coating being used to ensure the conductivity and contact reliability of signal transmission; Wherein, the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer and the contact substrate form a metallurgical bond through an atomic-level interdiffusion interface, and nano-alloy points with a size less than 10 nm are formed at the grain boundaries between the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer and the noble metal coating.

[0006] In a second aspect of the present invention, a method for preparing a signal connector is provided, the method for preparing the signal connector comprising: Performing electrochemical activation treatment on the surface of the contact substrate to remove oxides to form nucleation sites, and electrochemically co-depositing an Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer on the nucleation sites, so that the thickness of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is 12-18 nm; Performing noble metal deposition on the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer by using a rectangular pulse sequence, and superimposing bipolar micro-pulses to adjust the local ion mobility to obtain an initial coating; After the initial coating is formed, applying a continuous sweep frequency excitation signal in the range of 10-150 kHz to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, obtaining a frequency response characteristic curve through the acoustic signals generated by the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, calculating a thickness distribution cloud map of the initial coating based on the frequency response characteristic curve, and analyzing the mean square deviation of the thickness of each radial section in the thickness distribution cloud map to judge the uniformity of the initial coating.

[0007] Preferably, the performing electrochemical activation treatment on the surface of the contact substrate to remove oxides to form nucleation sites, and electrochemically co-depositing an Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer on the nucleation sites, includes: Using a mixed solution of citric acid and ascorbic acid as a first electrolyte, introducing it into a first electrolytic cell, and performing electrochemical activation treatment on the surface of the contact substrate by using a periodic reverse pulse current to remove surface oxides and form uniformly distributed nucleation sites with a spacing of 20-30 nm; Setting auxiliary cathodes parallel to the surface of the contact substrate on both sides of the second electrolytic cell, and applying an alternating magnetic field to make the Fe in the second electrolytic cell2+ , Ga 3+ , Cu 2+ ions move along the magnetic field lines and deposit on the nucleation sites to form a Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer with {100}-{110} crystal planes; A sodium melamine sulfonate solution is introduced onto the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to form amino ligand sites with a coordination density of 0.8 - 1.2 per nm 2 on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer.

[0008] Preferably, auxiliary cathodes parallel to the surface of the contact substrate are arranged on both sides of the second electrolytic cell, and an alternating magnetic field is applied to make the Fe 2+ , Ga 3+ , Cu 2+ ions move along the magnetic field lines and deposit on the nucleation sites to form a Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer with {100}-{110} crystal planes, including: A plurality of graphite auxiliary cathodes are uniformly arranged vertically on both side walls of the second electrolytic cell, and a conductive polymer layer covers the surface of each graphite auxiliary cathode, and a periodic micro-groove structure is formed on the surface of the conductive polymer layer; A second electrolyte containing Fe 2+ , Ga 3+ , Cu 2+ ions with a molar ratio of 2:1:1 is introduced into the second electrolytic cell, and sodium carboxymethyl cellulose is added to the second electrolyte, and an ordered molecular brush layer is formed by the sodium carboxymethyl cellulose on the surface of the conductive polymer layer; A sinusoidally modulated alternating magnetic field is applied to the graphite auxiliary cathode, and the sinusoidally modulated alternating magnetic field interacts with the micro-groove structure and the ordered molecular brush layer to form an ion enrichment region, and the Fe 2+ , Ga 3 + , Cu 2+ ions migrate along the periodic arrangement direction of the micro-groove structure to the surface of the nucleation sites; A pulsed ultrasonic field is introduced on the surface of the nucleation sites, and the pulsed ultrasonic field forms acoustic cavitation bubbles in the ion enrichment region, and the shock waves generated by the periodic collapse of the acoustic cavitation bubbles regulate the deposition orientation of the Fe 2+ , Ga 3+ , Cu 2+ ions, so that the Fe 2+ , Ga 3+ , Cu 2+ ions preferentially grow along the {100} and {110} crystal planes; The lock-in amplifier detection circuit is used to monitor the collapse frequency of the acoustic cavitation bubbles in real time, and the modulation period of the alternating magnetic field is adjusted according to the collapse frequency to control the alternating growth of the {100} crystal plane and the {110} crystal plane, so as to form a Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer with an orientation degree greater than 95%.

[0009] Preferably, a rectangular pulse sequence is used to deposit noble metals on the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, and a bipolar micro-pulse is superimposed to adjust the local ion mobility to obtain an initial coating, including: Based on the amino ligand sites on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, noble metal ions are adsorbed, and a rectangular pulse sequence is used for the first-stage deposition to form noble metal crystal nuclei; A bipolar micro-pulse is applied to the noble metal crystal nuclei to guide the preferential growth of noble metal ions along the {100}-{110} crystal planes of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to form an oriented coating; A partitioned cathode shielding structure is used to form an ion concentration gradient field on the surface of the oriented coating, and noble metal ions are guided to fill and grow along the grain boundary direction of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to form an initial coating.

[0010] Preferably, the bipolar micro-pulse is applied to the noble metal crystal nuclei to guide the preferential growth of noble metal ions along the {100}-{110} crystal planes of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to form an oriented coating, including: The region where the noble metal crystal nuclei are located is divided into a plurality of paired deposition units, and each pair of the deposition units are respectively located on the {100} crystal plane and the {110} crystal plane of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer; Reverse bipolar micro-pulses are applied to each pair of the deposition units. When a positive pulse is applied to the deposition unit on the {100} crystal plane, a negative pulse is applied to the deposition unit on the {110} crystal plane to form a noble metal ion concentration difference; According to the noble metal ion concentration difference, the duty cycle of the bipolar micro-pulse is adjusted to control the alternating deposition rate of the noble metal ions on the {100} crystal plane and the {110} crystal plane to form a noble metal thin layer with a grain size of 50-80 nm; A surfactant solution is introduced into the noble metal thin layer, and the surfactant solution forms an ordered assembly film on the surface of the noble metal thin layer. The ordered assembly film induces the continuous oriented growth of noble metal ions along the {100} crystal plane and the {110} crystal plane to form an oriented coating.

[0011] Preferably, after the formation of the initial coating, a continuous swept-frequency excitation signal in the range of 10 - 150 kHz is applied to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, and the frequency response characteristic curve is obtained through the acoustic signal generated by the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer. Based on the frequency response characteristic curve, the thickness distribution nephogram of the initial coating is calculated, and the mean square deviation of the thickness of each radial section in the thickness distribution nephogram is analyzed to judge the uniformity of the initial coating, including: The Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is excited by four groups of orthogonal swept-frequency signals with fundamental frequencies of 17 kHz, 23 kHz, 29 kHz, and 37 kHz respectively to obtain the magnetostrictive response signals at different depth positions; According to the phase difference and amplitude change of the magnetostrictive response signal, the mechanical vibration characteristics of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer at different depths are calculated to generate the frequency response characteristic curve; According to the corresponding relationship between the frequency shift and the coating thickness in the frequency response characteristic curve, a depth-frequency shift calibration curve is established, and the thickness distribution nephogram of the initial coating is calculated; The thickness distribution nephogram is divided into multiple radial regions with equal angular intervals, and the mean square deviation of the thickness in each radial region is calculated to generate the coating uniformity distribution map.

[0012] Preferably, the calculating the mechanical vibration characteristics of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer at different depths according to the phase difference and amplitude change of the magnetostrictive response signal to generate the frequency response characteristic curve includes: The magnetostrictive response signals of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer in the depth direction are collected in time series, and the phase difference information and amplitude information at each collection moment are extracted; According to the phase difference information, the propagation time delay of sound waves at different depths of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is calculated, and according to the amplitude information, the energy attenuation coefficient of sound waves at different depths of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is calculated; The propagation time delay and the energy attenuation coefficient are combined with the lattice strain coupling coefficients of Fe atoms, Ga atoms, and Cu atoms in the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to calculate the vibration differences of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer on the {100} crystal plane and the {110} crystal plane, and the mass load contribution and stress coupling contribution of the initial coating to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer are separated to obtain the mechanical vibration characteristics of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer; The mechanical vibration characteristics are Fourier-transformed according to the frequency to obtain the frequency response characteristic curve of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer.

[0013] Preferably, after determining the uniformity of the initial coating, the method for manufacturing the signal connector further includes: Determining the coating weak areas inside the micropores according to the mean square deviation of the thickness of each radial section in the thickness distribution cloud map, and dividing the coating weak areas into near-orifice areas, middle-section areas, and bottom-hole areas according to the depth positions of the micropores; Setting an annular anode array outside the micropores, and forming an axial electric field gradient inside the micropores by adjusting the potential differences of the respective annular anodes, and driving noble metal ions to migrate from the near-orifice areas to the bottom-hole areas inside the micropores; Applying an alternating magnetic field along the axial direction of the micropores to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, the frequency of the alternating magnetic field matching the inherent resonance frequency of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer and the phase leading the replenishing plating current pulse by 90°, and the alternating magnetic field generating a standing wave sound field inside the micropores; Under the action of the standing wave sound field, the noble metal ions form periodically distributed concentration nodes inside the micropores, and adjusting the frequency of the alternating magnetic field according to the positional relationship between the concentration nodes and the coating weak areas to control the deposition of the noble metal ions in the coating weak areas; Judging whether the coating thickness of the coating weak areas reaches a preset value by monitoring the magnetostrictive response signals of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer at different depth positions.

[0014] Preferably, after the coating thickness of the coating weak areas reaches the preset value, the method for manufacturing the signal connector further includes: Introducing hydrogen plasma into the micropores under a vacuum degree of 1 Pa, and the hydrogen plasma selectively reacting with the amino ligand sites on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to strip Fe atoms and Ga atoms layer by layer from the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer; Moving the stripped Fe atoms and Ga atoms to the initial coating by grain boundary diffusion, and the Fe atoms and Ga atoms forming nano-scale alloy points at the grain boundaries of the initial coating, the size of the nano-scale alloy points being less than 10 nm; During the formation of the nano-scale alloy points, applying a continuous frequency-sweeping signal to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to obtain a resonance spectrogram during the attenuation process; Comparing the frequency shift and attenuation coefficient in the resonance spectrogram with the original spectrogram to generate a stress distribution map and a structural integrity evaluation result of the coating on the inner wall of the micropores.

[0015] The signal connector provided by the first invention of this application integrates the detection function into the product structure itself ingeniously by constructing a Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer with a thickness of 12-18 nm on the surface of the contact substrate. This endogenous magnetosensitive layer forms a metallurgical bond with the contact substrate through an atomic-level interdiffusion interface and becomes an organic part of the contact, avoiding the problems of shedding or contamination that may be caused by externally attached markers. When excited by an external alternating magnetic field, the Fe-Ga-Cu layer generates characteristic acoustic signals directly related to the thickness of the noble metal coating, realizing non-contact and non-destructive detection of the distribution of the noble metal layer inside the high aspect ratio micro-holes. At the same time, nano-alloy points with a size less than 10 nm formed at the grain boundaries between the Fe-Ga-Cu layer and the noble metal coating enhance the interfacial bonding strength and improve the stability of the product under thermal cycling and mechanical stress. This innovative structure fundamentally solves the technical problem that traditional connectors cannot monitor the thickness distribution of the noble metal layer inside the micro-holes in real time, ensuring both manufacturing quality and providing the possibility for performance monitoring throughout the product life cycle, and significantly improving the reliability and service life of the signal connector.

[0016] The preparation method of the signal connector provided by the second invention of this application is as follows. First, electrochemical activation treatment is carried out on the surface of the contact substrate to remove oxides and form uniformly distributed nucleation sites, laying a foundation for subsequent precise deposition. Electrochemical co-deposition of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is carried out on these sites, and the thickness is precisely controlled within the range of 12-18 nm. When the thickness is less than 12 nm, the continuity of the magnetostrictive layer is insufficient and the magnetostrictive effect weakens, resulting in a decrease in detection sensitivity; when the thickness exceeds 18 nm, the internal stress of the magnetostrictive layer increases, and it will significantly increase the interfacial impedance between the coating and the substrate, affecting the signal transmission performance. The Fe-Ga-Cu ternary eutectic formulation has better mechanical properties and corrosion resistance compared to pure Fe-Ga alloys, while maintaining a high magnetostrictive coefficient, making it an ideal material for the detection layer. The key is that this nano-thin layer forms an atomic-level interdiffusion interface with the copper alloy substrate through electrochemical co-deposition and becomes an organic part of the contact body, rather than simply adhering.

[0017] Rectangular pulse sequences combined with bipolar micro-pulses are used for noble metal electroplating, realizing precise control of the coating distribution inside the micro-holes. Traditional DC electroplating has an obvious "electric field shielding effect" in high aspect ratio structures, making the electric field strength deep inside about 80% lower than that on the surface. The combined application of the rectangular main pulse and the bipolar micro-pulse solves this problem from the perspective of electrochemical kinetics: the main pulse (5-8 mA / cm 2)It provides the basic deposition driving force, promotes ion reduction during the "on" period, and allows ions in the solution to be replenished to the electrode surface through the diffusion mechanism during the "off" period; while the bipolar micropulse of 1-5 kHz plays a role at the microscopic level of ion migration. The negative pulse briefly changes the direction of the local electric field, destroys the concentration boundary layer in the micropores, and significantly improves the ion mass transfer efficiency in the depth. Electrochemical impedance analysis shows that this double-pulse technique increases the ion concentration ratio between the bottom and the opening of the micropores from 0.3 in the traditional process to above 0.85, fundamentally improving the coating uniformity.

[0018] The introduction of the Fe-Ga-Cu ternary eutectic ferromagnetic layer as an in-situ detection element has completely revolutionized the detection method of the coating inside the micropores. When a continuous swept-frequency excitation signal in the range of 10-150 kHz is applied to it, due to the magnetostrictive effect, this layer generates tiny mechanical vibrations and converts them into acoustic signals. Such acoustic signals carry rich coating information: as the surface coating thickness increases by 0.1 μm each time, the resonance frequency of the Fe-Ga-Cu layer will decrease by about 200 Hz, and the relationship between this frequency shift and the thickness remains highly linear, with the correlation coefficient R 2 > 0.98. Different from the destructive sampling detection after traditional electroplating, this in-situ sensing method realizes 100% non-destructive on-line detection, with a resolution better than 0.05 μm. More importantly, since the Fe-Ga-Cu layer is buried under the coating, it can be activated for detection at any time during the entire life cycle of the product, providing unprecedented possibilities for the long-term quality monitoring of the connector, significantly improving the product reliability and reducing the maintenance cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0020] Figure 1 It is a schematic diagram of an embodiment of the signal connector in the embodiment of the present invention; Figure 2 For Figure 1 the enlarged view at A of Figure 3 It is a schematic diagram of an embodiment of the preparation method of the signal connector in the embodiment of the present invention.

[0021] The realization of the purpose, functional features and advantages of the present invention will be further described with reference to the embodiments and the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0024] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In addition, "and / or" throughout the text includes three scenarios. Taking A and / or B as an example, it includes the technical solution of A, the technical solution of B, and the technical solution that both A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, which must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0025] An embodiment of the present application provides a signal connector. Please refer to Figure 2 and Figure 3 , the signal connector includes: A contact base 1, on which a microporous structure 3 is provided; An Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer provided on the surface of the contact base 1, the thickness of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is 12 - 18 nm, and the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is used to generate mechanical vibration and generate an acoustic signal under the excitation of an external alternating magnetic field, and the frequency characteristics of the acoustic signal shift with the change of the coating thickness; A noble metal coating provided on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, the thickness of the noble metal coating is uniformly distributed along the axial and radial directions of the microporous structure 3, and the noble metal coating is used to ensure the conductivity and contact reliability of signal transmission; Among them, the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer and the contact substrate 1 form a metallurgical bond through an atomic-level interdiffusion interface, and nano-alloy points with a size less than 10 nm are formed at the grain boundaries of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer and the noble metal coating.

[0026] It should be noted that the signal connector includes, in addition to the core conductive structure composed of the contact substrate 1, the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer (not shown in the figure) and the noble metal coating (not shown in the figure), an insulator housing 2 and a metal shielding cover (not shown in the figure) for cooperative use. The contact substrate 1 is made of a high-conductivity copper alloy material, and a microporous structure 3 with a high aspect ratio is provided on the surface, including blind holes or through holes with a depth-to-diameter ratio greater than 5:1. These microporous structures 3 (i.e., blind holes or through holes) provide both mechanical connection functions and participate in signal transmission characteristic modulation. The Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer uniformly covers the surface of the contact substrate 1, including the inner walls of the micropores, and the thickness is precisely controlled within the range of 12-18 nm. This thickness can ensure sufficient magnetostrictive sensitivity without significantly affecting the electrical conductivity. The Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is a functional material with a high magnetostrictive coefficient. When an external alternating magnetic field is applied, it will generate mechanical vibrations proportional to the field strength and generate characteristic acoustic signals. The frequency characteristics of these acoustic signals will undergo a systematic shift with the change in the thickness of the noble metal coating covering it, thereby realizing the non-destructive detection function of the thickness of the noble metal coating. The noble metal coating is provided on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer and is composed of noble metals such as gold, silver, or palladium. The thickness is uniformly distributed along the axial and radial directions of the microporous structure 3 to ensure the electrical conductivity of signal transmission and the contact reliability of anti-oxidation. An atomic-level interdiffusion interface is formed between the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer and the contact substrate 1 through electrochemical co-deposition, establishing a strong metallurgical bond and avoiding the peeling risk that may exist in traditional coatings; at the same time, nano-alloy points with a size less than 10 nm are formed at the grain boundaries of the Fe-Ga-Cu layer and the noble metal coating. These nano-alloy points enhance the interfacial bonding strength and improve the stability of the product under thermal cycling and mechanical stress. Through this innovative structural design, the signal connector of the present invention realizes the organic combination of the self-detection function and the conductive function, fundamentally solving the technical problem that traditional connectors cannot monitor the thickness distribution of the noble metal layer inside the micropores in real time, and providing a hardware guarantee for high-reliability signal transmission.

[0027] Another embodiment of the present application provides a method for manufacturing a signal connector. Figure 3 It is a flowchart of a method for manufacturing a signal connector provided in an embodiment of the present application. In this embodiment, the method includes: Please refer to Figure 3, the surface of the contact substrate is electrochemically activated to remove oxides and form nucleation sites, and electrochemical co-deposition of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is carried out on the nucleation sites, so that the thickness of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is 12-18 nm; In one embodiment of the present invention, the electrochemical activation treatment of the surface of the contact substrate to remove oxides and form nucleation sites, and the electrochemical co-deposition of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer on the nucleation sites include: Taking a mixed solution of citric acid and ascorbic acid as the first electrolyte, introducing it into the first electrolytic cell, and using a periodic reverse pulse current to electrochemically activate the surface of the contact substrate to remove surface oxides and form uniformly distributed nucleation sites with a spacing of 20-30 nm; Auxiliary cathodes parallel to the surface of the contact substrate are arranged on both sides of the second electrolytic cell, and an alternating magnetic field is applied to make the Fe 2+ , Ga 3+ , Cu 2+ ions move along the magnetic field line direction, and a Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer with {100}-{110} crystal planes is deposited on the nucleation sites; Sodium melamine sulfonate solution is introduced onto the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to form amino ligand sites with a coordination density of 0.8-1.2 per nm 2 on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer.

[0028] The following specifically describes the steps involved in the above embodiments: The electrochemical activation treatment of the surface of the contact substrate uses a mixed solution of citric acid and ascorbic acid as the first electrolyte. Citric acid is a polycarboxylic organic acid that can form soluble complexes with metal ions on the surface of copper alloys; ascorbic acid is used as a reducing agent to prevent the newly exposed metal surface from being oxidized again. Surface oxides refer to dense thin layers such as copper oxide (CuO) and cuprous oxide (Cu2O) formed on the copper alloy of the contact substrate in the air. These oxides hinder the adhesion and uniformity of the subsequent coating. In the forward pulse stage of the periodic reverse pulse current, the current flows from the external power supply to the contact surface; in the reverse pulse stage, the current direction is instantaneously reversed, and the oxide layer on the contact surface is peeled off due to local electrolysis, and the exposed fresh metal surface forms nucleation sites. Nucleation sites refer to micro-regions with high surface energy and chemical activity, which serve as the positions where metal ions are preferentially adsorbed and reduced during the subsequent co-deposition process. The site spacing is controlled within the range of 20-30 nm. This spacing is most suitable for the orderly growth of Fe-Ga-Cu nano-crystals, ensuring both the continuity of the magnetostrictive layer and avoiding the decline of magnetic properties caused by excessive grain aggregation.

[0029] The electrochemical co - deposition of the Fe - Ga - Cu ternary eutectic nano - magnetostrictive layer is carried out in the second electrolytic cell. The auxiliary cathode is made of graphite or stainless steel and serves as an electric - field control element rather than the main site of electrodeposition. The alternating magnetic field makes the Fe 2+ , Ga 3 + , Cu 2+ ions move along the direction of the magnetic field lines. Magnetic field lines are imaginary curves in a magnetic field that represent the direction of the magnetic induction intensity. Ions are deflected under the action of the Lorentz force in the magnetic field, forming a directional migration path. Metal ions are orderly reduced and deposited on the nucleation sites, forming a Fe - Ga - Cu ternary eutectic nano - magnetostrictive layer with {100}-{110} crystal planes. The {100} and {110} crystal planes refer to crystallographic planes represented by Miller indices. These two crystal planes exhibit the maximum magnetostrictive effect under the action of a magnetic field, that is, the property of the material to produce deformation under the action of a magnetic field. The Fe - Ga - Cu ternary eutectic refers to an alloy structure formed by three elements, iron, gallium, and copper, in a specific ratio, which has better mechanical strength and corrosion stability than a single Fe - Ga alloy while maintaining excellent magnetostrictive properties.

[0030] The surface functionalization of the Fe - Ga - Cu ternary eutectic nano - magnetostrictive layer is achieved by introducing a sodium melamine sulfonate solution to the surface. Sodium melamine sulfonate contains a triazine ring and a sulfonate group. The nitrogen atoms and sulfonic acid groups in its molecular structure can form coordination bonds with the metal atoms on the surface of the Fe - Ga - Cu layer. A coordination bond refers to a chemical bond formed by the electron pair in the ligand (sodium melamine sulfonate molecule) and the empty orbital of the central metal atom (surface Fe or Cu atom). After treatment, an amino ligand site with a coordination density of 0.8 - 1.2 per nm 2 is formed on the surface. An amino ligand site refers to the active site exposed after the - NH - group in the sodium melamine sulfonate molecule forms a coordination with the surface metal atom. These sites can form strong interactions with subsequent noble metal ions, promoting uniform nucleation. Coordination density refers to the number of ligand sites per unit area. This density range is optimized for the subsequent electroplating process: too low a density leads to insufficient nucleation, and too high a density increases the internal stress of the coating. Both situations will affect the quality and uniformity of the final coating.

[0031] In one embodiment of the present invention, auxiliary cathodes parallel to the surface of the contact substrate are arranged on both sides of the second electrolytic cell, and an alternating magnetic field is applied to make the Fe 2+ , Ga 3+ , Cu 2+ ions in the second electrolytic cell move along the direction of the magnetic field lines and deposit on the nucleation sites to form a Fe - Ga - Cu ternary eutectic nano - magnetostrictive layer with {100}-{110} crystal planes, including: A plurality of graphite auxiliary cathodes are uniformly arranged vertically on both side walls of the second electrolytic cell. The surface of each graphite auxiliary cathode is covered with a conductive polymer layer, and a periodic micro-groove structure is formed on the surface of the conductive polymer layer; A second electrolyte containing Fe, Ga, and Cu ions with a molar ratio of 2:1:1 is introduced into the second electrolytic cell, and sodium carboxymethylcellulose is added to the second electrolyte. The sodium carboxymethylcellulose forms an ordered molecular brush layer on the surface of the conductive polymer layer; 2+ Fe 3+ Ga 2+ Cu A sinusoidally modulated alternating magnetic field is applied to the graphite auxiliary cathode. The sinusoidally modulated alternating magnetic field interacts with the micro-groove structure and the ordered molecular brush layer to form an ion enrichment region. The Fe, Ga, and Cu ions in the ion enrichment region migrate along the periodic arrangement direction of the micro-groove structure to the surface of the nucleation site; 2+ Fe 3 + Ga 2+ Cu A pulsed ultrasonic field is introduced on the surface of the nucleation site. The pulsed ultrasonic field forms acoustic cavitation bubbles in the ion enrichment region. The shock waves generated by the periodic collapse of the acoustic cavitation bubbles regulate the deposition orientation of the Fe, Ga, and Cu ions, enabling the Fe, Ga, and Cu ions to preferentially grow along the {100} and {110} crystal planes; 2+ Fe 3+ Ga 2+ Cu 2+ Fe 3+ Ga 2+ Cu A lock-in amplifier detection circuit is used to monitor the collapse frequency of the acoustic cavitation bubbles in real time. The modulation period of the alternating magnetic field is adjusted according to the collapse frequency to control the alternating growth of the {100} and {110} crystal planes, forming an Fe-Ga-Cu ternary eutectic nano-magneto layer with an orientation degree greater than 95%.

[0032] The following is a specific description of the steps involved in the above embodiments: The second electrolytic cell is constructed of transparent organic glass material, and eight graphite auxiliary cathodes are uniformly arranged on both side walls along the vertical direction at an interval of 5 mm. The graphite auxiliary cathode refers to a conductive element with high-purity graphite as the base material and serving as an auxiliary electrode, which is a cylinder with a diameter of 2 mm and a length of 30 mm. The surface of each graphite auxiliary cathode is covered with a conductive polymer layer, which is a conductive thin film with a thickness of 200 - 300 nm formed by electrochemical deposition of polypyrrole. A periodic microgroove structure is formed on the surface of the conductive polymer layer. The microgroove structure refers to a microscopic morphology with regularly arranged grooves on the surface, which is formed on the polypyrrole layer surface by laser interference lithography technology. The groove width is 500 nm, the depth is 100 nm, and the spacing between adjacent grooves is 1 μm. This microgroove structure can produce an electric field enhancement effect in a local area and provide a directional channel for ion migration. For example, this structure is similar to the gate channel in microelectronic processes, and the migration rate of ions along the groove direction is 2 - 3 times higher than that perpendicular to the groove direction, thus realizing the directional control of ion flow.

[0033] The second electrolyte is introduced into the second electrolytic cell. The second electrolyte is prepared from ferrous sulfate (0.2 mol / L), gallium sulfate (0.1 mol / L), and copper sulfate (0.1 mol / L), and the molar ratio of Fe 2+ , Ga 3+ , Cu 2+ ions is experimentally verified to be most favorable for the alternating growth of {100}-{110} crystal planes. The molar ratio refers to the ratio of the amounts of substances of each substance in a chemical reaction. This ratio ensures that the Fe element dominates in the alloy, while the Ga and Cu elements can stabilize the alloy structure and enhance the magnetostrictive effect. Sodium carboxymethyl cellulose with a concentration of 0.5 g / L is added to the second electrolyte. Sodium carboxymethyl cellulose is a water-soluble polymer compound, and its molecular chain contains a large number of carboxyl and hydroxyl functional groups. Sodium carboxymethyl cellulose molecules adsorb on the surface of the conductive polymer layer to form an ordered molecular brush layer. The ordered molecular brush layer refers to a brush-like molecular arrangement structure in which one end of the sodium carboxymethyl cellulose molecule is fixed on the surface and the other end extends into the solution, with a thickness of about 10 - 15 nm. Under the condition that the pH value of the electrolyte is 2.5 - 3.0, the carboxyl group (-COO - ) in the carboxymethyl group forms a complex with Fe 2+ ions, enhancing the enrichment degree of Fe 2+ ions on the electrode surface. After adding sodium carboxymethyl cellulose, the concentration of Fe 2+ ions on the electrode surface is 3 - 4 times higher than that in the solution, significantly improving the electrodeposition efficiency and crystal orientation selectivity. In addition, sodium carboxymethyl cellulose can also reduce the surface tension of the electrolyte, improve the wettability of the electrolyte to the microgrooves, and ensure that ions can be evenly distributed to the bottom of the microgroove structure during the deposition process.

[0034] A sinusoidally modulated alternating magnetic field is applied to the graphite-assisted cathode. Specifically, a helical coil is sleeved outside the electrolytic cell, and a sinusoidal alternating current with a frequency of 100 Hz and a peak magnetic induction intensity of 15 mT is passed through. The sinusoidally modulated alternating magnetic field refers to a magnetic field whose magnetic field intensity changes according to the sine function law. Its modulation method is the superposition of the fundamental frequency of 100 Hz and the third harmonic (300 Hz), and the modulation depth is 30%. The alternating magnetic field interacts with the microgroove structure and the ordered molecular brush layer to form an ion enrichment region in the microgrooves. The ion enrichment region refers to a micro-region where the local ion concentration is significantly higher than that of the bulk solution, mainly distributed at the bottom of the microgrooves. The specific mechanism is as follows: The alternating magnetic field makes the charged ions move in a circular motion. When the ion motion trajectory matches the geometric size of the microgrooves, the ions are confined in the grooves; at the same time, the carboxyl groups in the ordered molecular brush layer complex with Fe 2+ ion complexation further enhances the local enrichment of ions. Electrochemical impedance spectroscopy analysis shows that the concentrations of Fe 2+ 、Ga 3+ 、Cu 2+ ions in the enrichment region are 5-7 times higher than those in the bulk solution. These ions migrate directionally to the surface of the nucleation site along the periodic arrangement direction of the microgroove structure (i.e., the long axis direction of the groove). The magnetic field intensity is selected as 15 mT because at this intensity, the Larmor radius of the ions matches the width of the microgrooves most appropriately. When it is lower than this value, the regulation effect of the magnetic field on the ion motion is not obvious, and when it is higher than this value, the excessive Lorentz force will cause the ions to deviate from the expected trajectory.

[0035] A pulsed ultrasonic field is introduced on the surface of the nucleation site by installing an ultrasonic transducer with a frequency of 40 kHz and a power of 60 W at the bottom of the electrolytic cell. The pulsed ultrasonic field refers to an ultrasonic field that is intermittently turned on at a certain frequency. The pulse on time is 2 ms and the off time is 8 ms. When ultrasonic waves propagate in the electrolyte, acoustic cavitation bubbles are formed in the negative pressure phase. Acoustic cavitation bubbles refer to microbubbles formed, grown, and collapsed in the liquid under the action of the sound field, with a diameter generally of 5-50 μm. These bubbles periodically collapse at the peak sound pressure, generating an instantaneous high temperature of up to 10 4 K and a shock wave of 10 3 atmospheres. The shock wave regulates the deposition orientation of Fe 2+ 、Ga 3+ 、Cu 2+ ions, making these ions preferentially grow along the {100} and {110} crystal planes. The specific principle is as follows: The stress field generated by the shock wave on the crystal plane is related to the crystal plane energy. The {100} and {110} crystal planes with lower energy are less affected by the shock wave than other high-index crystal planes, so it is kinetically favorable for the preferential growth of the low-index crystal planes.

[0036] The phase-locked amplification detection circuit is used to monitor the collapse frequency of acoustic cavitation bubbles in real time. The phase-locked amplification detection circuit refers to an electronic circuit system that can extract specific frequency signals from the noise background, mainly composed of a preamplifier, a phase-sensitive detector, and a low-pass filter. In a specific implementation, a piezoelectric sensor is installed on the electrolytic cell wall to detect the acoustic pressure signal generated by the collapse of acoustic cavitation bubbles. The signal is pre-amplified and then sent to the phase-locked amplifier. The phase-locked amplifier uses the driving signal of the ultrasonic transducer as a reference to extract the components with the same frequency as the reference signal, obtaining the bubble collapse frequency information. The bubble collapse frequency is usually an integer multiple of the ultrasonic frequency, reflecting the energy distribution of the sound field in the electrolyte. Adjust the modulation period of the alternating magnetic field according to the collapse frequency. The modulation period refers to the time required for the magnetic field modulation to complete a full change. When the detected bubble collapse frequency decreases (indicating that the growth of the {100} crystal plane dominates), increase the proportion of the 300 Hz component in the alternating magnetic field to promote the growth of the {110} crystal plane; otherwise, reduce the proportion of the 300 Hz component to promote the growth of the {100} crystal plane. Through this real-time feedback adjustment, the alternating growth of the {100} crystal plane and the {110} crystal plane is realized, and finally a Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer with an orientation degree greater than 95% is formed. The orientation degree refers to the percentage of a specific crystal plane in the total crystal planes of the material. An orientation degree greater than 95% means that the total proportion of the {100} and {110} crystal planes in the sample exceeds 95%. The high orientation degree ensures that the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer generates the maximum magnetostrictive effect under an external magnetic field.

[0037] Please continue to refer to Figure 3 , a rectangular pulse sequence is used to deposit noble metals on the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, and bipolar micro-pulses are superimposed to adjust the local ion mobility to obtain an initial coating; In an embodiment of the present invention, the step of using a rectangular pulse sequence to deposit noble metals on the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer and superimposing bipolar micro-pulses to adjust the local ion mobility to obtain an initial coating includes: Based on the adsorption of noble metal ions at the amino ligand sites on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, a rectangular pulse sequence is used for the first-stage deposition to form noble metal crystal nuclei; Bipolar micro-pulses are applied to the noble metal crystal nuclei to guide the preferential growth of noble metal ions along the {100}-{110} crystal planes of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to form an oriented coating; A partitioned cathode shielding structure is used to form an ion concentration gradient field on the surface of the oriented coating, and noble metal ions are guided to fill and grow along the grain boundary direction of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to form an initial coating.

[0038] The following specifically describes the steps involved in the above embodiments: In the first stage of noble metal deposition, the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer treated with sodium melamine sulfonate is placed in a noble metal electroplating bath. The electrolyte in the electroplating bath is potassium gold cyanide solution with a concentration of 10 g / L, and the pH value is adjusted to 10.0 - 10.5. The amino ligand sites refer to the active sites formed by the -NH- groups in the sodium melamine sulfonate molecules on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer. These sites form coordination bonds with noble metal ions (such as Au + ) to enrich the noble metal ions on the surface. A coordination bond is a chemical bond in which the electrons in the shared electron pair mainly come from one atom or group. Connect a DC power supply to a waveform generator to generate a rectangular pulse sequence. The main characteristics of this sequence are: peak current density 5 - 8 mA / cm 2 , pulse width 10 ms, and pulse interval 40 ms. A rectangular pulse sequence refers to a pulsed current in which the current density is rectangularly distributed in time. Its characteristic is that the current density remains constant during the pulse duration and then rapidly drops to zero. In the "on" stage of the pulse, the noble metal ions are reduced to form noble metal crystal nuclei; in the "off" stage of the pulse, the noble metal ions in the solution are replenished to the electrode surface by diffusion. A noble metal crystal nucleus refers to a tiny crystal particle initially formed by the aggregation of a small number of noble metal atoms, with a diameter of about 5 - 10 nm. It can be observed by atomic force microscopy that these crystal nuclei are evenly distributed on the amino ligand sites, and the nucleus density reaches 10 12 nuclei / cm 2 . When electroplating with a rectangular pulse sequence, the "on" stage of the pulse provides an appropriate current density to promote the formation of crystal nuclei, while the "off" stage of the pulse allows the ions in the electrolyte to fully diffuse to the electrode surface, effectively overcoming the diffusion limitation problem in high aspect ratio structures. The peak current density of 5 - 8 mA / cm 2 and the on-off ratio of 10 ms:40 ms balance the crystal nucleus formation rate and the ion diffusion rate, ensuring that a sufficient number of evenly distributed crystal nuclei can also be formed deep in the micropores.

[0039] The preferential growth control of noble metal crystal nuclei is achieved by using bipolar micro-pulse technology through a multi-channel pulse power supply. Bipolar micro-pulses refer to small-amplitude pulses with alternating positive and negative polarities and higher frequencies superimposed on the main pulse sequence. Their parameters are: frequency 1 - 5 kHz, the amplitude of the positive pulse is 20% of the main pulse, the amplitude of the negative pulse is 10% of the main pulse, and the time ratio of positive and negative pulses is 1:1. Such pulses are precisely generated by a programmable power supply and applied to the noble metal crystal nuclei that have already formed on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer. Preferential growth refers to the phenomenon that crystals preferentially grow in a specific crystal plane direction. The negative pulses in the bipolar micro-pulses generate lower current densities on the {100} and {110} crystal planes than on the high-index crystal planes because the atomic arrangements on the {100} and {110} crystal planes are more closely packed and the surface charge density is lower. This causes noble metal ions to preferentially deposit on the {100} and {110} crystal planes, forming an oriented coating. An oriented coating refers to a coating with highly consistent grain orientations. The thickness of the oriented coating formed by this method is approximately 200 - 300 nm and preferentially grows along the {100} and {110} crystal planes of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer. The frequency range (1 - 5 kHz) of the bipolar micro-pulses is carefully designed to match each pulse period with the adsorption-desorption kinetic process of metal ions on the crystal plane. Too low a frequency cannot effectively control the crystal growth direction, while too high a frequency will interfere with the normal deposition process of ions. The amplitude ratio of positive and negative pulses (20%:10%) ensures that there is sufficient deposition current and appropriate dissolution current in each cycle for selective control of crystal plane growth. This precise control enables the oriented coating to maintain a uniform orientation even inside the micropores and to maintain a good crystal orientation even in regions far from the pore mouth.

[0040] After the oriented coating is formed, a partitioned cathode shielding structure is used to complete the coating filling. The partitioned cathode shielding structure is a specially designed electrode system composed of multiple independently controlled shielding units. Each shielding unit is a stainless steel sheet with a diameter of 0.5 mm, and is positioned 0.2 - 0.3 mm above the micropore opening area through a precision displacement platform. These shielding units are connected to separate power channels and can apply a potential of -0.2 to -0.5 V (relative to the reference electrode). The electric field interference generated by the shielding units forms an ion concentration gradient field in the micropores. The ion concentration gradient field refers to the area where the ion concentration changes orderly in space, usually manifested as a gradual decrease in ion concentration from the pore opening to the pore bottom. By precisely adjusting the potential of each shielding unit, the ion concentration gradient is formed along the grain boundary direction of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer. The grain boundary is the interface area between adjacent grains, where the atomic arrangement is relatively disordered. Due to the higher energy in the grain boundary area, noble metal ions preferentially deposit and fill in these positions. The ions migrate and deposit along the grain boundary direction under the action of the concentration gradient to form an initial coating. The initial coating is a continuous metal layer that fills the grain boundaries and covers the entire surface, with a thickness of about 0.8 - 1.2 μm. The positioning height (0.2 - 0.3 mm) of the shielding units is a key parameter, and this range can precisely regulate the electric field distribution without hindering the flow of the electrolyte. The potential range of the shielding units (-0.2 to -0.5 V) can generate sufficient electric field disturbance to regulate ion migration, while not completely blocking the growth of the coating. This partitioned cathode shielding structure creatively solves the problem of uneven electric field distribution in high aspect ratio blind holes, enabling ions to migrate to the deep part of the micropores along a predetermined path and ensuring the uniformity of the coating thickness on the inner wall of the entire micropore.

[0041] In one embodiment of the present invention, applying a bipolar micro-pulse to the noble metal crystal nuclei to guide the preferential growth of noble metal ions along the {100}-{110} crystal planes of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to form an oriented coating includes: Dividing the region where the noble metal crystal nuclei are located into multiple pairs of deposition units, and each pair of the deposition units is respectively located on the {100} crystal plane and the {110} crystal plane of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer; Applying reverse bipolar micro-pulses to each pair of the deposition units. When a positive pulse is applied to the deposition unit on the {100} crystal plane, a negative pulse is applied to the deposition unit on the {110} crystal plane to form a noble metal ion concentration difference; Adjusting the duty cycle of the bipolar micro-pulse according to the noble metal ion concentration difference to control the alternating deposition rate of the noble metal ions on the {100} crystal plane and the {110} crystal plane, and forming a noble metal thin layer with a grain size of 50 - 80 nm; A surfactant solution is introduced into the noble metal thin layer, and an ordered assembly film is formed on the surface of the noble metal thin layer. The ordered assembly film induces the continuous growth of noble metal ions along the orientations of the {100} crystal plane and the {110} crystal plane to form an oriented coating.

[0042] The following specifically describes the steps involved in the above embodiments: The division of the region where the noble metal crystal nuclei are located is carried out using a digital high-resolution positioning system. First, the crystal plane orientation of the surface of the Fe-Ga-Cu ternary eutectic nanomagnetostrictive layer is analyzed using an electron backscatter diffraction instrument to obtain the distribution maps of the {100} crystal plane and the {110} crystal plane. The data processing system compares the obtained diffraction pattern with the standard crystal plane diffraction pattern to identify the precise positions and ranges of the {100} crystal plane and the {110} crystal plane. A deposition unit refers to a micro-region that receives the same electrical treatment during the electroplating process, with an area of approximately 10×10 μm 2 . A pair of deposition units refers to two micro-regions that are adjacent in spatial position and have different crystal plane orientations, one located on the {100} crystal plane and the other on the {110} crystal plane. The system divides the surface into hundreds of such pairs of deposition units according to the crystal plane distribution. To achieve precise control, a microelectrode array technology is adopted, and a microelectrode tip with a diameter of 5 μm is placed approximately 100 μm above each deposition unit. Taking the actual application in a high aspect ratio micro-hole as an example, the interior of a micro-hole with a diameter of 500 μm and a depth of 2000 μm usually contains approximately 300 - 500 pairs of such deposition units, distributed at different depths and radial positions in the micro-hole. This division method enables the subsequent electroplating process to be precisely controlled according to the differences in crystal plane orientations, overcoming the limitations in traditional electroplating methods where it is difficult to identify and selectively process different crystal planes.

[0043] Applying reverse bipolar micro-pulses to each pair of deposition units is achieved using a multi-channel precision current source. A bipolar micro-pulse refers to a short-time pulsed current with alternating positive and negative polarities superimposed on the base current, with a pulse width of 50 - 100 μs and a frequency of 1 - 10 kHz. Reverse means that in a pair of deposition units, when the deposition unit on the {100} crystal plane receives a positive pulse (current flows from the power supply to the workpiece), the corresponding deposition unit on the {110} crystal plane simultaneously receives a negative pulse (current flows from the workpiece to the power supply), and then alternates. The positive pulse current density is set to 10 - 15 mA / cm², and the negative pulse current density is set to 5 - 8 mA / cm 2。The pulse current waveforms output by each microelectrode are synchronously regulated by a computer control system to ensure that the paired deposition units receive reverse pulses with precise timing. The forward pulse promotes the reduction and deposition of precious metal ions on this crystal plane, while the negative pulse dissolves the deposited metal atoms within a weak range and repels the precious metal ions in the solution at the same time. This reverse treatment makes the {100} crystal plane and the {110} crystal plane alternately become the ion enrichment region and the depletion region, forming a precious metal ion concentration difference. The precious metal ion concentration difference refers to the difference in ion concentration between adjacent regions, usually manifested as the concentration in the enrichment region being 3 - 5 times that in the depletion region. The generation of this ion concentration difference stems from the difference in electric field intensity generated by bipolar micro-pulses on different crystal planes. The atomic arrangement density and surface energy of the {100} crystal plane and the {110} crystal plane are different, resulting in different responses to the electric field.

[0044] Adjusting the duty cycle of the bipolar micro-pulse according to the precious metal ion concentration difference is completed by a real-time feedback control system. The duty cycle refers to the percentage of the duration of the forward pulse in the total cycle time within a pulse period. The electroplating system uses a reference electrode to monitor the precious metal ion concentration in different regions of the solution in real time. The monitoring data is collected by a high-speed data acquisition card at a frequency of 1 kHz, and the ion concentration difference near each deposition unit is calculated through a dedicated algorithm. When it is detected that the ion concentration in the {100} crystal plane region drops below the set threshold (usually 70% of the initial concentration), the system automatically increases the forward pulse duty cycle on the {100} crystal plane (from 40% to 60%), and at the same time decreases the forward pulse duty cycle on the {110} crystal plane (from 40% to 20%), causing the precious metal ions to migrate preferentially to the {100} crystal plane. After a sufficient thickness of the coating accumulates on the {100} crystal plane, the system adjusts the duty cycle in the reverse direction to promote the growth of the {110} crystal plane. This dynamic regulation enables the precious metal ions to be alternately deposited on the {100} crystal plane and the {110} crystal plane, forming a precious metal thin layer with a grain size of 50 - 80 nm. The grain size refers to the average diameter of a single metal crystal, and the control within the range of 50 - 80 nm is the result of optimization. This size range enables the grains to have sufficient mechanical strength and stability, while maintaining good ductility and responsiveness to crystal orientations. If the grain size is less than 50 nm, grain boundary slip is likely to occur under stress; if it is greater than 80 nm, the crystal orientation control effect decreases, and it is difficult to form a highly oriented structure.

[0045] The surfactant solution is introduced into the noble metal thin layer by the circulating flow immersion method. The surfactant solution is prepared from cetyltrimethylammonium bromide (CTAB), with a concentration of 0.5 - 1.0 mmol / L, the pH value adjusted to 6.0 - 7.0, and the temperature controlled at 35 ± 2 °C. The sample with the formed noble metal thin layer is immersed in the surfactant solution for 20 - 30 minutes, while the solution is circulated at a flow rate of 5 - 10 mL / min through a precision peristaltic pump to ensure that the surfactant molecules can also fully contact the inside of the micropores. The surfactant molecules adsorb on the surface of the noble metal thin layer to form an ordered assembly film. The ordered assembly film refers to an ordered molecular layer formed by the spontaneous arrangement of surfactant molecules on the solid surface, with a thickness of about 2 - 3 nm. CTAB molecules have a hydrophilic head (quaternary ammonium group) and a hydrophobic tail (alkyl chain), forming a monolayer or bilayer structure on the metal surface. This ordered assembly film has selective adsorption characteristics for different crystal planes, forming molecular patterns on the {100} and {110} crystal planes whose arrangement directions match the atomic arrangement of the crystal planes. Infrared spectroscopy and contact angle measurement confirm that the adsorption configurations of CTAB molecules on the {100} and {110} crystal planes are different. On the {100} crystal plane, they are mainly arranged parallel to the surface, while on the {110} crystal plane, they are arranged obliquely. The ordered assembly film induces the continuous growth of noble metal ions along the orientations of the {100} and {110} crystal planes through electrostatic and coordination interactions, forming an oriented coating. The oriented coating refers to a continuous metal layer with highly consistent grain orientations, with a thickness of about 0.5 - 0.8 μm. The CTAB concentration is controlled within the range of 0.5 - 1.0 mmol / L because this concentration range is exactly near the critical micelle concentration of CTAB, enabling the surfactant molecules to form a complete monolayer on the noble metal surface without forming an overly thick multi-layer structure that would hinder the growth of subsequent coatings.

[0046] Please continue to refer to Figure 3 , after the formation of the initial coating, a continuous swept-frequency excitation signal in the range of 10 - 150 kHz is applied to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer. The frequency response characteristic curve is obtained through the acoustic signals generated by the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer. Based on the frequency response characteristic curve, the thickness distribution cloud map of the initial coating is calculated, and the mean square deviation of the thickness of each radial cross-section in the thickness distribution cloud map is analyzed to judge the uniformity of the initial coating.

[0047] In one embodiment of the present invention, after the initial coating is formed, a continuous swept-frequency excitation signal in the range of 10 - 150 kHz is applied to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, and a frequency response characteristic curve is obtained through the acoustic signal generated by the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer. Based on the frequency response characteristic curve, a thickness distribution contour map of the initial coating is calculated, and the root mean square deviation of the thickness of each radial section in the thickness distribution contour map is analyzed to determine the uniformity of the initial coating, including: The Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is excited by four groups of orthogonal swept-frequency signals with fundamental frequencies of 17 kHz, 23 kHz, 29 kHz, and 37 kHz respectively to obtain magnetostrictive response signals at different depth positions; According to the phase difference and amplitude change of the magnetostrictive response signal, the mechanical vibration characteristics of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer at different depths are calculated to generate a frequency response characteristic curve; According to the correspondence between the frequency shift and the coating thickness in the frequency response characteristic curve, a depth-frequency shift calibration curve is established to calculate the thickness distribution contour map of the initial coating; The thickness distribution contour map is divided into a plurality of radial regions with equal angular intervals, and the root mean square deviation of the thickness in each radial region is calculated to generate a coating uniformity distribution map.

[0048] The following specifically describes the steps involved in the above embodiments: Measurement of the thickness distribution of the Fe-Ga-Cu ternary eutectic nanomagnetostrictive layer is first excited by an orthogonal swept-frequency signal. The orthogonal swept-frequency signal refers to four groups of frequency-sweeping signals that are perpendicular to each other in space and are generated by four Helmholtz coils. The installation positions of these four coils are as follows: the first group is along the horizontal X direction of the electroplating equipment, the second group is along the horizontal Y direction, the third group is along the vertical Z direction, and the fourth group is configured in a cross direction rotated by 45°, that is, the coil plane forms equal angles with the X, Y, and Z coordinate axes at the same time. The cross direction refers to the spatial direction that is not parallel to the main coordinate axes. Through this arrangement, the magnetic field components along the diagonal direction can be captured, forming a complete electromagnetic coverage of the entire three-dimensional space. Each group of coils is driven by an independent signal generator, and sine wave signals with fundamental frequencies of 17 kHz, 23 kHz, 29 kHz, and 37 kHz are output, with peak currents of 0.5 - 1.0 A. These four fundamental frequencies are selected as relatively prime numbers to avoid harmonic interference between the frequency components. 17 kHz is suitable for detecting areas closer to the surface (0 - 5 μm), 23 kHz is suitable for detecting medium depths (5 - 10 μm), 29 kHz is for deeper areas (10 - 15 μm), and 37 kHz is used for detecting the deepest areas (15 - 20 μm). For high aspect ratio micro-hole structures, such as blind holes with a diameter of 100 μm and a depth of 500 μm, frequency scans within the range of ±500 Hz can be superimposed on the four fundamental frequencies respectively to form a complete swept-frequency excitation. When these alternating magnetic fields act on the Fe-Ga-Cu ternary eutectic nanomagnetostrictive layer, due to the magnetostrictive effect, the material will generate tiny mechanical vibrations. The magnetostrictive effect refers to the phenomenon that ferromagnetic materials deform under the action of a magnetic field. The length change rate of Fe-Ga-Cu materials under an external magnetic field is about 200 - 300 ppm. The Fe-Ga-Cu layers at different depth positions are affected differently by the coating mass load, so their responses to the magnetic field are also different. This response difference is captured as the magnetostrictive response signal. The magnetostrictive response signal refers to the mechanical vibration signal generated by the Fe-Ga-Cu layer under magnetic field excitation and is detected and recorded by a piezoelectric sensor or a laser interferometer.

[0049] The calculation of the mechanical vibration characteristics of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer is based on the analysis of phase difference and amplitude variation. The phase difference refers to the time delay between the magnetostrictive response signal and the excitation signal, expressed in degrees. The amplitude variation refers to the law of the response signal intensity changing with frequency. The response signal is collected by a high-sensitivity piezoelectric sensor array, and each sensor is responsible for collecting the vibration signal at a specific spatial position. After being amplified by a preamplifier, the signal is digitized by a data acquisition system at a sampling rate of 100 kHz. The data processing system first performs band-pass filtering on the collected signal to filter out environmental noise and system harmonics, and then converts the time-domain signal into a frequency-domain signal through the fast Fourier transform (FFT). In the frequency domain, the system extracts the phase and amplitude information of the response signal at each excitation frequency. For different depth positions inside the microporous structure, the phase difference is proportional to the depth, while the amplitude shows a decaying trend with the increase in depth. The calculation process uses a phase tracking algorithm to perform phase continuity processing on the signals within four groups of fundamental frequencies and their swept frequency ranges, eliminating the errors caused by phase jumps. At the same time, amplitude normalization processing is adopted to compare the signal amplitudes at different depths with the reference amplitude at the surface position to obtain the normalized amplitude curve. The mechanical vibration characteristics include parameters such as resonance frequency, quality factor, and damping coefficient, and these parameters together constitute the frequency response characteristic curve. The frequency response characteristic curve refers to the graphical representation of the response amplitude and phase changing with frequency, visually showing the vibration behavior of the system at different frequencies. For the Fe-Ga-Cu layer covered with a coating, obvious frequency displacement phenomena will occur in its frequency response characteristic curve, and this displacement is closely related to the coating thickness.

[0050] The correspondence between the frequency shift and the coating thickness is established by using a depth-frequency shift calibration curve. The frequency shift refers to the offset of the resonance frequency of the Fe-Ga-Cu layer covered with the coating compared to the area without the coating, with the unit of Hz. First, prepare standard samples with different known coating thicknesses (ranging from 0.2 μm to 2.0 μm, with an interval of 0.1 μm), and measure the frequency response characteristic curves of these samples using the above orthogonal swept-frequency excitation method, recording the frequency shift values at each thickness. By fitting these data points using the least squares method, a functional relationship between the frequency shift and the coating thickness is established to form a depth-frequency shift calibration curve. For the actual measurement in high aspect ratio microholes, the system sets multiple virtual measurement points in the axial and radial directions of the microhole to form a three-dimensional measurement grid. For each measurement point, according to its frequency shift value, the coating thickness at the corresponding position is obtained by querying the calibration curve. The thickness data of all measurement points are combined to form a thickness distribution cloud map of the initial coating. The thickness distribution cloud map is a three-dimensional visualization image representing the coating thickness at different positions with color or gray-scale changes, intuitively showing the thickness distribution of the coating inside the microhole. For the typical microhole structure of a signal connector contact, the thickness distribution cloud map can accurately display the coating thickness values at each position from the hole mouth to the hole bottom, with a resolution of up to 0.1 μm. This non-destructive testing method can monitor the coating growth process in real time and provide a direct basis for coating quality control.

[0051] The generation of the coating uniformity distribution map adopts the radial partition statistical analysis method. First, establish a cylindrical coordinate system for the thickness distribution cloud map in the three-dimensional space according to the geometric center of the microhole, and then divide the entire microhole area into multiple radial areas with equal angular intervals. The radial area refers to the fan-shaped area extending radially outward from the central axis of the microhole, and the angular interval is usually set to 15° or 30°, forming 12 or 24 radial areas. For each radial area, it is further subdivided into multiple depth layers along the axial direction. For example, a 500-μm deep microhole is divided into 10 depth layers, with each layer being 50 μm. In each depth layer of each radial area, calculate the mean square deviation of the thickness of all measurement points in this area. The mean square deviation of the thickness refers to the degree of deviation of the coating thickness from the average value, and the calculation formula is the sum of the squares of the differences between the thickness values of the measurement points and the average thickness divided by the number of measurement points. The smaller the mean square deviation value, the more uniform the coating thickness in this area. The system arranges the mean square deviation values of all radial areas and depth layers according to the spatial position to generate a coating uniformity distribution map. The uniformity distribution map is in the form of a heat map, using different colors to identify the mean square deviation values of different areas. Dark red indicates a large mean square deviation (non-uniform area), and dark blue indicates a small mean square deviation (uniform area). This analysis method can accurately locate the areas with poor coating uniformity inside the microhole and provide a basis for subsequent precise re-plating. In the manufacture of signal connectors, the coating uniformity directly affects the electrical performance and reliability of the product. Under the guidance of the uniformity distribution map, the electroplating parameters can be adjusted targeted to improve the product quality consistency.

[0052] In an embodiment of the present invention, calculating the mechanical vibration characteristics of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer at different depths according to the phase difference and amplitude change of the magnetostrictive response signal, and generating a frequency response characteristic curve, includes: Performing time-series acquisition on the magnetostrictive response signals of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer in the depth direction, and extracting the phase difference information and amplitude information at each acquisition moment; Calculating the propagation delay of sound waves at different depths of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer according to the phase difference information, and calculating the energy attenuation coefficient of sound waves at different depths of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer according to the amplitude information; Combining the propagation delay and the energy attenuation coefficient with the lattice strain coupling coefficients of Fe atoms, Ga atoms, and Cu atoms in the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, calculating the vibration differences of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer on the {100} crystal plane and the {110} crystal plane, separating the mass load contribution and stress coupling contribution of the initial coating to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, and obtaining the mechanical vibration characteristics of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer; Performing Fourier transform on the mechanical vibration characteristics according to frequency to obtain the frequency response characteristic curve of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer.

[0053] The following specifically describes the steps involved in the above embodiments: For the time-series acquisition of the magnetostrictive response signals of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, a micro-sensing array system is adopted according to the characteristics of the microporous structure. The depth direction refers to the axial direction from the microporous opening to the bottom. Considering the size characteristics that the diameter of the signal connector micropores is usually 20 - 100 μm and the depth is 100 - 500 μm, traditional sensors cannot be directly placed inside the micropores. Therefore, a micro piezoelectric sensor array is arranged in a circular pattern around the micropores. The diameter of the sensor is 50 μm, the sensitivity is 30 mV / g, and the response frequency range is 5 - 100 kHz. Time-series acquisition means continuously recording the signal change process at each depth position in the time dimension. Signal acquisition is to receive the vibration waves generated by the Fe-Ga-Cu layer in the micropores through an external sensor and conduct them to the outside. The sampling rate is set to 200 kHz. For micropores with a diameter of only 50 μm, sound waves will generate multiple reflections and diffractions during propagation, forming a complex interference pattern. In view of this characteristic, a hybrid time-domain - frequency-domain deconvolution technique is used to process the original signal to separate the response components directly from different depth positions. This signal processing method suitable for the microporous structure can overcome the complexity of sound wave propagation in the microscale space and extract the phase difference information and amplitude information.

[0054] The analysis of acoustic wave propagation characteristics needs to consider the waveguide effect of the microporous structure. For micropores with a diameter of 50 μm, the acoustic wave propagation exhibits obvious waveguide characteristics, and the propagation mode is significantly different from that in free space. The calculation of the propagation delay needs to introduce a waveguide correction factor, which is related to the ratio of the micropore diameter to the acoustic wavelength. For an excitation signal of 17 kHz, its wavelength is about 200 - 300 μm, which is larger than the micropore diameter, causing the acoustic wave to mainly propagate in the fundamental mode. The calculation of the energy attenuation coefficient needs to consider the reflection loss on the micropore wall surface, especially for blind holes with a high aspect ratio (such as a length-to-diameter ratio of 10:1). Due to the limitation of the micropore size, multiple measurement points cannot be placed inside, and the energy attenuation coefficient is calculated indirectly: by analyzing the composite echo signal measured at the micropore opening, using the time window separation technique to identify the echo components from different depths, and then calculating the energy attenuation at each depth position. This analysis method suitable for the space-limited conditions of micropores captures the internal structure information through external sensing, achieving non-destructive measurement of the acoustic characteristics in a tiny space.

[0055] The vibration difference analysis is specifically optimized for the geometric characteristics of micropores. Considering that the internal plating layer of the micropore is mainly distributed on the side wall, the measurement system focuses on the radial vibration mode. The lattice strain coupling coefficient shows directional differences in the micropore environment, with different coupling strengths along the radial and axial directions. The {100} and {110} crystal planes of the Fe-Ga-Cu layer on the side wall of the micropore also exhibit different directional vibration characteristics, but due to the limiting effect of the micropore structure, this difference will be partially suppressed by the waveguide effect. For this characteristic, the system uses a deconvolution algorithm to extract the pure crystal plane vibration characteristics from the composite response. For typical signal connector micropores (such as blind holes with a diameter of 50 μm and a depth of 300 μm), the mass loading contribution mainly comes from the precious metal plating layer with a thickness of 1 - 2 μm, while the stress coupling contribution is related to the surface roughness of the inner wall of the micropore and the bonding property of the plating interface. When implementing the separation algorithm, the singular value decomposition method of multi-band data is used to decompose the mixed response into two independent components dominated by mass and stress, ensuring accurate mechanical vibration characteristic data can also be obtained in the complex acoustic environment of micropores.

[0056] The process of obtaining the frequency response characteristic curve has also been adaptively adjusted according to the characteristics of the micro-hole structure. Due to the limited internal space of the micro-hole, it is difficult to place multiple measurement points to obtain a complete vibration mode. Therefore, an indirect reconstruction method is adopted. By using the frequency response data measured at the opening of the micro-hole and combining the known geometric parameters and material properties of the micro-hole, the frequency response characteristics at different depths inside the micro-hole are reconstructed through the inverse acoustic propagation algorithm. For blind holes with a high aspect ratio (such as an aspect ratio of 10:1), multiple characteristic peaks will appear on the frequency response characteristic curve, corresponding to the resonant frequencies at different axial positions of the micro-hole. The system establishes a distribution map of the coating thickness inside the micro-hole by comparing the displacements of the characteristic peaks in the coated area and the uncoated area. This frequency response analysis method applicable to the micro-hole structure overcomes the application limitations of traditional methods in a small space and realizes precise non-destructive detection of the coating on the inner wall of micro-holes with a diameter of only dozens of micrometers and a depth of hundreds of micrometers. The measurement accuracy can reach ±0.1 μm, fully meeting the high-reliability requirements of signal connectors.

[0057] In an embodiment of the present invention, after judging the uniformity of the initial coating, the method for manufacturing the signal connector further includes: Determine the coating weak areas inside the micro-hole according to the mean square deviation of the thickness of each radial section in the thickness distribution cloud map, and divide the coating weak areas into a near-hole opening area, a middle section area, and a hole bottom area according to the depth position of the micro-hole; Set an annular anode array outside the micro-hole, and form an axial electric field gradient inside the micro-hole by adjusting the potential difference of each annular anode. The axial electric field gradient drives precious metal ions to migrate from the near-hole opening area to the hole bottom area; Apply an alternating magnetic field along the axial direction of the micro-hole to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer. The frequency of the alternating magnetic field matches the inherent resonance frequency of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, and the phase is 90° ahead of the replenishing plating current pulse. The alternating magnetic field induces a standing wave sound field inside the micro-hole; Under the action of the standing wave sound field, the precious metal ions form periodically distributed concentration nodes inside the micro-hole. According to the positional relationship between the concentration nodes and the coating weak areas, adjust the frequency of the alternating magnetic field to control the deposition of the precious metal ions in the coating weak areas; Judge whether the coating thickness in the coating weak areas reaches a preset value by monitoring the magnetostrictive response signals of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer at different depth positions.

[0058] The following specifically describes the steps involved in the above embodiments: The determination of the weak plating regions is carried out by using the thickness distribution contour map analysis method. First, the thickness distribution contour map is imported into the image analysis software, and the parameters for dividing the radial cross-section are set. The radial cross-section refers to the planar slice along the radius direction of the micro-hole. Usually, the circumference of the micro-hole is evenly divided into 12 angles, and a radial cross-section is set every 30°. The mean square deviation of thickness is calculated for each radial cross-section. The mean square deviation of thickness refers to the arithmetic mean of the sum of the squares of the thickness values of each measurement point deviating from the average thickness, which reflects the degree of dispersion of the plating thickness distribution. When the mean square deviation of thickness in a certain region exceeds the preset threshold (usually 15% of the average thickness), this region is marked as a weak plating region. A weak plating region refers to a region where the plating thickness is significantly lower than the design requirements or the distribution is uneven. According to the depth position of the micro-hole, the micro-hole is equally divided into three sections from the opening to the bottom: the first 1 / 3 part close to the opening of the micro-hole is the near-orifice region, the middle 1 / 3 part is the middle section region, and the deepest 1 / 3 part is the bottom region. For a typical micro-hole of a signal connector (such as a blind hole with a diameter of 50μm and a depth of 300μm), it can be specifically divided into: the depth of 0 - 100μm is the near-orifice region, 100 - 200μm is the middle section region, and 200 - 300μm is the bottom region. This zoning method takes into account the different characteristics of the electric field distribution and ion transport in the micro-hole, and formulates different plating repair strategies for different regions. By analyzing the mean square deviation distribution map of each region, the positions that need to be repaired with key plating can be accurately located, providing a target navigation for subsequent precise plating repair.

[0059] The annular anode array is set in a concentric surrounding layout. Along the axis, 3 - 5 annular anodes are evenly arranged outside the micro-hole. Each annular anode is composed of multiple independently controlled anode units. The annular anode refers to the anode electrode distributed in a ring around the micro-hole. The inner diameter of each annular anode is slightly larger than the diameter of the micro-hole, usually set to 1.2 - 1.5 times the diameter of the micro-hole. For a micro-hole with a diameter of 50μm, the inner diameter of the annular anode is about 60 - 75μm, the thickness is 0.5mm, and the distance between adjacent annular anodes is 50 - 100μm. The annular anode array is fixed above the micro-hole through a precision positioning system, and the distance between the lowermost annular anode and the plane of the micro-hole opening is controlled within the range of 30 - 50μm. Each annular anode is connected to a multi-channel power supply system, and the potentials are set respectively as follows: the potential of the annular anode closest to the micro-hole opening is 1.0V (relative to the reference electrode), the potential of the annular anode in the middle position is 1.2V, and the potential of the annular anode farthest from the micro-hole opening is 1.5V. Through this increasing potential difference setting, an axial electric field gradient is formed in the micro-hole. The axial electric field gradient refers to the rate of change of the electric field strength along the axial direction of the micro-hole, and the electric field gradually increases from the orifice to the bottom. This electric field distribution pattern generates a directional driving force on the positively charged precious metal ions, making them preferentially migrate from the near-orifice region to the bottom region. For a micro-hole with a length-to-diameter ratio of 6:1, this electric field gradient design can increase the current density in the bottom region by about 50%, effectively overcoming the problem of weak plating at the bottom in traditional electroplating.

[0060] The alternating magnetic field is applied by a precisely controlled magnetic field generating device. First, the inherent resonance frequency of the Fe-Ga-Cu ternary eutectic nanomagnetic layer is determined by frequency sweeping test. The inherent resonance frequency refers to the frequency of natural vibration of the material without external force. For a Fe-Ga-Cu layer with a thickness of 15nm, its inherent resonance frequency is usually in the range of 20-25kHz. The output frequency of the magnetic field generator is precisely adjusted to the measured inherent resonance frequency, and the magnetic field intensity is controlled in the range of 10-15mT. The application direction of the alternating magnetic field is along the axial direction of the micropore, and is generated by the Helmholtz coils set at the upper and lower ends of the micropore. For a micropore with a diameter of 50μm and a depth of 300μm, a Helmholtz coil with a diameter of 5mm is configured, and the center of the coil coincides with the axis of the micropore. The phase of the alternating magnetic field leads the plating current pulse by 90°. This phase relationship is achieved by a phase locking circuit to ensure that the magnetostrictive vibration reaches the maximum value just before each plating current pulse arrives. Phase advance means that the time change of the alternating magnetic field leads the time change of the current pulse, which is manifested as an advance in the waveform timing. The alternating magnetic field induces a standing wave acoustic field in the micropore. The standing wave acoustic field refers to a stable waveform formed by the superposition of the incident wave and the reflected wave, characterized by the presence of fixed nodes (points with zero amplitude) and antinodes (points with the largest amplitude). Since the geometric shape of the micropore serves as an acoustic boundary condition, the standing wave acoustic field forms a specific spatial distribution pattern in the micropore, causing periodic pressure changes in the liquid medium, thereby affecting the migration and deposition behavior of ions.

[0061] Precious metal ions are distributed periodically under the action of standing wave acoustic field. The pressure gradient in the acoustic field causes ions to gather at the antinode position and become sparse at the node position, forming concentration nodes. Concentration nodes refer to the distribution structure in which the ion concentration changes periodically with space, and its spatial period is equal to half of the wavelength of the sound wave. For ultrasonic waves with a frequency of 20kHz, the wavelength in aqueous solution is about 7.5cm, and the half wavelength is about 3.75cm, which is greater than the micropore depth. Therefore, a single complete node-antinode structure is usually formed in the micropore. The node position of the standing wave acoustic field can be adjusted by precisely controlling the frequency of the alternating magnetic field. When the frequency increases, the wavelength shortens and the node position moves toward the bottom of the micropore; when the frequency decreases, the wavelength increases and the node position moves toward the mouth of the micropore. According to the position of the weak area of ​​the coating determined by the previous thickness distribution cloud map, the frequency of the alternating magnetic field is adjusted so that the concentration antinode (ion-enriched area) coincides with the weak area. For example, for the weak plating area in the middle of the micropore, the alternating magnetic field frequency can be set to 22-24kHz; for the weak plating area in the bottom of the hole, the frequency can be increased to 25-27kHz. Through this acoustic field control method, the enrichment and preferential deposition of precious metal ions in specific areas can be achieved, forming a targeted local re-plating effect. The re-plating current adopts a pulse waveform synchronized with the alternating magnetic field, and the peak current density is 5-8mA / cm 2, the pulse width is 5 - 10 ms. This sound field-assisted precise repair plating technology significantly improves the electroplating uniformity deep in the micro-holes, reducing the effect of thick plating at the hole mouth and thin plating in the middle section, which is common in blind holes.

[0062] The coating thickness monitoring uses real-time magnetostrictive response analysis technology. During the repair plating process, a detection signal is continuously applied to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer. The frequency of the detection signal is offset from the frequency of the alternating magnetic field used for repair plating, usually set at the repair plating frequency ±2 kHz to avoid signal interference. The magnetostrictive response signals at different depth positions are collected by a high-sensitivity piezoelectric sensor array. After pre-amplification and band-pass filtering, the signals are sent to the signal processing system. The frequency characteristics of the magnetostrictive response signals change with the increase in coating thickness, specifically manifested as a decrease in resonance frequency and a decrease in response amplitude. Setting the preset value is a key control parameter in the repair plating process. The preset value refers to the target thickness value that the weak areas of each coating need to reach, usually set at 90 - 95% of the thickness of the surrounding normal area. For the typical requirements of signal connectors, the preset value is usually 0.8 - 1.2 μm. The system calculates the frequency displacement value of each monitoring point in real time and converts the frequency displacement into a thickness increment through the calibration curve established in advance. When it is detected that the coating thickness in a certain area reaches the preset value, the system automatically adjusts the frequency of the alternating magnetic field to move the concentration wave belly to the next area that needs to be repaired. If the coating thickness of all weak areas reaches the preset value, the repair plating process automatically terminates. This closed-loop control mechanism ensures the accuracy and efficiency of the repair plating process, avoiding over-deposition and waste of resources.

[0063] In an embodiment of the present invention, after the coating thickness in the weak area of the coating reaches the preset value, the method for manufacturing the signal connector further includes: Introducing hydrogen plasma into the micro-hole under a vacuum of 1 Pa. The hydrogen plasma selectively reacts with the amino ligand sites on the surface of the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer, causing Fe atoms and Ga atoms to be gradually peeled off from the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer; Moving the peeled Fe atoms and Ga atoms to the initial coating through grain boundary diffusion. The Fe atoms and Ga atoms form nano-scale alloy points at the grain boundaries of the initial coating, and the size of the nano-scale alloy points is less than 10 nm; During the formation of the nano-scale alloy points, applying a continuous frequency-sweeping signal to the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer to obtain a resonance spectrum diagram during the attenuation process; Comparing the frequency displacement and attenuation coefficient in the resonance spectrum diagram with the original spectrum diagram to generate a stress distribution diagram and a structural integrity evaluation result of the coating on the inner wall of the micro-hole.

[0064] The following specifically describes the steps involved in the above embodiments: The hydrogen plasma treatment is implemented using a low-temperature plasma reaction system. First, the signal connector that has completed electroplating is placed in a vacuum chamber, and the chamber vacuum is reduced to 1 Pa through a pumping system composed of a mechanical pump and a molecular pump. Vacuum degree refers to the measurement of gas pressure in a vacuum system. 1 Pa is approximately 1 / 100000 of the atmospheric pressure. In this low-pressure environment, the mean free path of gas molecules increases significantly, which is beneficial to the formation and maintenance of plasma. Hydrogen with a purity of 99.999% is introduced into the vacuum chamber, and the flow rate is controlled at 5 - 10 sccm (standard cubic centimeters per minute). Hydrogen plasma is generated in the chamber through a radio-frequency power supply. The radio-frequency power is set at 50 - 100 W, and the frequency is 13.56 MHz. Hydrogen plasma is a mixed gas containing electrons, protons, and hydrogen radicals formed by the ionization of hydrogen gas under the action of an electric field, presenting a pink glow. In the plasma, active hydrogen atoms selectively react with the amino ligand sites on the surface of the Fe-Ga-Cu ternary eutectic nanomagnetic layer. Amino ligand sites refer to the active sites containing -NH- groups formed by sodium melamine sulfonate molecules on the surface of the Fe-Ga-Cu layer, which form coordination bonds with metal atoms. Active hydrogen atoms preferentially react with the nitrogen atoms in the amino ligand sites to form N-H bonds, breaking the original nitrogen-metal coordination bonds, and causing Fe atoms and Ga atoms to be gradually peeled off from the Fe-Ga-Cu ternary eutectic nanomagnetic layer layer by layer. The treatment time is controlled within the range of 30 - 60 seconds. For the micro-hole structure of the signal connector (such as a blind hole with a diameter of 50 μm and a depth of 300 μm), hydrogen plasma can enter the micro-holes through plasma diffusion and gas molecule collision, achieving uniform treatment of the entire inner wall surface. The advantage of this low-temperature plasma treatment is that the reaction process temperature is low (not exceeding 80 °C), which will not affect the mechanical properties of the coating and the substrate material, and at the same time has high selectivity, only acting on specific chemical bonds.

[0065] The migration process of the stripped Fe atoms and Ga atoms is realized by means of solid-state diffusion mechanism. After hydrogen plasma treatment, the signal connector is subjected to low-temperature annealing treatment, with the temperature controlled at 120 - 150 °C and the time being 20 - 30 minutes. This temperature range is lower than the tempering temperature of the substrate material, but is sufficient to provide the thermal activation energy required for the diffusion of Fe and Ga atoms. The stripped Fe atoms and Ga atoms migrate into the initial coating through the grain boundary diffusion mechanism. Grain boundary diffusion refers to the process in which atoms migrate along the interfaces between crystal grains, and the diffusion activation energy is lower than that of intragranular diffusion, which can occur at lower temperatures. The initial coating refers to the noble metal layer deposited on the inner wall of the micropores in the early stage, with a thickness of about 0.8 - 1.2 μm. The Fe and Ga atoms migrate along the grain boundary network of the noble metal coating and aggregate at the grain boundary intersections to form nano-scale alloy points. Nano-scale alloy points refer to the mixed-phase regions formed by Fe, Ga atoms and noble metal atoms, which are spherical or ellipsoidal in shape, with the size controlled below 10 nm. These alloy points are distributed at the grain boundaries of the coating, with an average spacing of 50 - 100 nm. The size less than 10 nm is the result of optimization. Overly large alloy points will reduce the conductivity and corrosion resistance of the coating, while overly small ones are difficult to effectively strengthen the grain boundary structure. For the application scenario of signal connectors, this dispersed distribution of nano-scale alloy points can pin the grain boundary dislocations, improve the mechanical strength and thermal stability of the coating, and at the same time, due to the small volume of individual alloy points, it will not significantly affect the conductivity. Transmission electron microscope observations show that these nano-scale alloy points are mainly distributed at the grain boundary triple points of the coating, forming a network strengthening structure, effectively improving the stability of the coating under thermal cycling and mechanical stress.

[0066] The monitoring of the formation process of nanoscale alloy dots uses real-time swept-frequency analysis technology. A continuous swept-frequency signal is applied to the Fe-Ga-Cu ternary eutectic nanomagnetostrictive layer by using Helmholtz coils. The swept-frequency range is 10 - 50 kHz, the swept-frequency rate is 1 kHz / s, and the swept-frequency cycle interval is 5 seconds. The continuous swept-frequency signal refers to an alternating magnetic field signal whose frequency changes continuously with time and is used to excite the magnetostrictive response of the material at different frequencies. As Fe and Ga atoms are gradually peeled off and migrate, the magnetostrictive performance of the Fe-Ga-Cu layer gradually decays, manifested as the displacement of the resonant peak frequency and the decrease in amplitude. The resonance spectrum diagram refers to the response amplitude curve of the material under different frequency excitations, and its main characteristics include the resonant frequency (the frequency point where the amplitude reaches the peak) and the quality factor (the sharpness of the resonant peak). The change of the resonance spectrum diagram of the Fe-Ga-Cu layer during the attenuation process is collected by a high-sensitivity piezoelectric sensor array, and a complete frequency response curve is recorded every 5 seconds. For the micro-hole structure of the signal connector, the response signals of the near-orifice region, the middle section region, and the bottom region of the hole are collected respectively, and a three-dimensional resonance spectrum evolution diagram is drawn to visually display the dynamic changes of the material properties during the formation process of nanoscale alloy dots. The gradual broadening and displacement of the resonant peak reflect the degree of transformation of the Fe-Ga-Cu layer into the noble metal coating. When the amplitude of the resonant peak decreases to less than 20% of the initial value, it indicates that the peeling and migration process is basically completed, and at this time, the annealing treatment is terminated. This non-contact real-time monitoring method avoids the disadvantages of the traditional method that requires multiple interruptions of the processing process for detection, and improves the continuity and efficiency of the process.

[0067] The evaluation of the coating quality is achieved through comparative analysis of resonance spectra. The final resonance spectrogram during the attenuation process is compared with the original spectrogram before treatment to extract two key parameters: frequency shift and attenuation coefficient. The frequency shift refers to the offset of the resonance peak frequency after treatment relative to the original frequency, reflecting the degree of change in the material structure; the attenuation coefficient refers to the attenuation ratio of the resonance peak amplitude after treatment relative to the original amplitude, reflecting the integrity of the transformation of the Fe-Ga-Cu layer. By performing spatial interpolation on the frequency shift data at different positions within each micropore, a coating stress distribution map is generated. The stress distribution map is a chart that visualizes the internal stress state of the coating on the inner wall of the micropore in the form of a color gradient, where red represents high tensile stress areas, blue represents high compressive stress areas, and green represents stress equilibrium areas. Similarly, based on the attenuation coefficient data, a structural integrity evaluation result is generated. The structural integrity evaluation result is a comprehensive judgment on whether there are defects such as microcracks and pores in the coating, usually expressed as a percentage of the integrity level. Gaussian weighted algorithm is used for data processing to smooth the original data, and then bivariate spline interpolation is applied to generate a continuous spatial distribution map. For the quality control of signal connectors, the stress distribution should be uniform without obvious stress concentration areas, and the structural integrity evaluation result should not be lower than 90%. This evaluation method transforms the Fe-Ga-Cu ternary eutectic nano-magnetostrictive layer from a simple detection means into a quality index for the entire product life cycle, achieving both precise control of the manufacturing process and providing benchmark data for performance monitoring during subsequent service processes.

[0068] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A signal connector, characterized in that: include: A contact substrate, wherein the contact substrate is provided with a microporous structure; An Fe-Ga-Cu ternary eutectic nanomagnetic layer is arranged on the surface of the contact substrate, the thickness of the Fe-Ga-Cu ternary eutectic nanomagnetic layer is 12-18nm, and the Fe-Ga-Cu ternary eutectic nanomagnetic layer is used to generate mechanical vibration and generate an acoustic signal under the excitation of an external alternating magnetic field, and the frequency characteristics of the acoustic signal shift as the thickness of the coating changes; A noble metal coating is disposed on the surface of the Fe-Ga-Cu ternary eutectic nanomagnetic layer, the thickness of the noble metal coating is uniformly distributed along the axial and radial directions of the microporous structure, and the noble metal coating is used to ensure the conductivity and contact reliability of signal transmission; The Fe-Ga-Cu ternary eutectic nanomagnetic layer and the contact substrate are metallurgically bonded through an atomic-level interdiffusion interface, and nanoscale alloy dots with a size less than 10 nm are formed at the grain boundaries between the Fe-Ga-Cu ternary eutectic nanomagnetic layer and the precious metal coating.

2. A method for preparing a signal connector, characterized in that: The preparation process of the signal connector according to claim 1 adopts the preparation method of the signal connector, and the preparation method of the signal connector comprises: Performing electrochemical activation treatment on the surface of the contact substrate to remove oxides to form nucleation sites, and electrochemically co-depositing a Fe-Ga-Cu ternary eutectic nanomagnetic layer on the nucleation sites, so that the thickness of the Fe-Ga-Cu ternary eutectic nanomagnetic layer is 12-18 nm; A rectangular pulse sequence is used to deposit noble metals on the Fe-Ga-Cu ternary eutectic nanomagnetic layer, and a bipolar micropulse is superimposed to adjust the local ion mobility to obtain an initial coating; After the initial coating is formed, a continuous frequency sweep excitation signal in the range of 10-150kHz is applied to the Fe-Ga-Cu ternary eutectic nanomagnetic layer, a frequency response characteristic curve is obtained through the acoustic signal generated by the Fe-Ga-Cu ternary eutectic nanomagnetic layer, a thickness distribution cloud map of the initial coating is calculated based on the frequency response characteristic curve, the mean square deviation of the thickness of each radial section in the thickness distribution cloud map is analyzed, and the uniformity of the initial coating is determined.

3. The method for preparing a signal connector according to claim 2, characterized in that: The electrochemical activation treatment is performed on the surface of the contact substrate to remove oxides to form nucleation sites, and the Fe-Ga-Cu ternary eutectic nanomagnetic layer is electrochemically co-deposited on the nucleation sites, including: A mixed solution of citric acid and ascorbic acid is used as a first electrolyte and passed into a first electrolytic cell, and a periodic reverse pulse current is used to perform electrochemical activation treatment on the surface of the contact substrate to remove surface oxides and form uniformly distributed nucleation sites with a spacing of 20-30 nm; Auxiliary cathodes parallel to the surface of the contact substrate are arranged on both sides of the second electrolytic cell, and an alternating magnetic field is applied to make the Fe 2+ , Ga 3+ , Cu 2+ The ions move along the direction of the magnetic field lines and deposit on the nucleation sites to form a Fe-Ga-Cu ternary eutectic nanomagnetic layer with {100}-{110} crystal planes; A sodium melamine sulfonate solution is introduced into the surface of the Fe-Ga-Cu ternary eutectic nanomagnetic layer to form a coordination density of 0.8-1.2 per nm on the surface of the Fe-Ga-Cu ternary eutectic nanomagnetic layer. 2 The amino coordination site.

4. The method for preparing a signal connector according to claim 3, characterized in that: Auxiliary cathodes parallel to the surface of the contact substrate are arranged on both sides of the second electrolytic cell, and an alternating magnetic field is applied to make the Fe 2+ , Ga 3 + , Cu 2+ The ions move along the direction of the magnetic field lines and deposit on the nucleation sites to form a Fe-Ga-Cu ternary eutectic nanomagnetic layer having a {100}-{110} crystal plane, comprising: A plurality of graphite auxiliary cathodes are evenly arranged on both side walls of the second electrolytic cell in a vertical direction, the surface of each graphite auxiliary cathode is covered with a conductive polymer layer, and a periodic micro-groove structure is formed on the surface of the conductive polymer layer; The second electrolytic cell was charged with Fe in a molar ratio of 2:1:

1. 2+ , Ga 3+ , Cu 2+ A second electrolyte containing ions, and adding sodium carboxymethyl cellulose to the second electrolyte, wherein the sodium carboxymethyl cellulose forms an ordered molecular brush layer on the surface of the conductive polymer layer; A sinusoidally modulated alternating magnetic field is applied to the graphite auxiliary cathode, and the sinusoidally modulated alternating magnetic field interacts with the micro-groove structure and the ordered molecular brush layer to form an ion-enriched region, wherein the Fe 2+ , Ga 3+ , Cu 2 + Ions migrate to the surface of the nucleation site along the periodic arrangement direction of the micro-groove structure; A pulsed ultrasonic field is introduced on the surface of the nucleation site, and the pulsed ultrasonic field forms acoustic cavitation bubbles in the ion-enriched area. The shock waves generated by the periodic collapse of the acoustic cavitation bubbles regulate the Fe 2+ , Ga 3+ , Cu 2+ The deposition orientation of the ions makes the Fe 2+ , Ga 3+ , Cu 2+ Ions grow preferentially along {100} and {110} crystal planes; A phase-locked amplifier detection circuit is used to monitor the collapse frequency of the acoustic cavitation bubbles in real time, and the modulation period of the alternating magnetic field is adjusted according to the collapse frequency to control the alternating growth of the {100} crystal plane and the {110} crystal plane to form a Fe-Ga-Cu ternary eutectic nanomagnetic layer with an orientation degree greater than 95%.

5. The method for preparing a signal connector according to claim 2, characterized in that: The method of using a rectangular pulse sequence to deposit noble metals on the Fe-Ga-Cu ternary eutectic nanomagnetic layer and superimposing a bipolar micropulse to adjust the local ion mobility to obtain an initial coating includes: Based on the adsorption of noble metal ions by the amino coordination sites on the surface of the Fe-Ga-Cu ternary eutectic nanomagnetic layer, a rectangular pulse sequence is used to perform the first stage deposition to form noble metal nuclei; Applying bipolar micro-pulses to the noble metal nuclei to guide the noble metal ions to preferentially grow along the {100}-{110} crystal planes of the Fe-Ga-Cu ternary eutectic nanomagnetic layer to form an oriented coating; A partitioned cathode shielding structure is used to form an ion concentration gradient field on the surface of the oriented coating, and noble metal ions are guided to fill and grow along the grain boundary direction of the Fe-Ga-Cu ternary eutectic nanomagnetic layer to form an initial coating.

6. The method for preparing a signal connector according to claim 5, characterized in that: The step of applying bipolar micro-pulses to the noble metal nuclei to guide the noble metal ions to preferentially grow along the {100}-{110} crystal planes of the Fe-Ga-Cu ternary eutectic nanomagnetic layer to form an oriented coating comprises: Dividing the region where the noble metal nuclei are located into a plurality of pairs of deposition units, each pair of the deposition units being located on the {100} crystal plane and the {110} crystal plane of the Fe-Ga-Cu ternary eutectic nanomagnetic layer respectively; Applying reverse bipolar micro-pulses to each pair of the deposition units, when a positive pulse is applied to the deposition unit of the {100} crystal plane, a negative pulse is applied to the deposition unit of the {110} crystal plane, so as to form a noble metal ion concentration difference; The duty cycle of the bipolar micropulse is adjusted according to the concentration difference of the noble metal ions, and the alternating deposition rate of the noble metal ions on the {100} crystal plane and the {110} crystal plane is controlled to form a noble metal thin layer with a grain size of 50-80 nm; A surfactant solution is introduced into the precious metal thin layer, and the surfactant solution forms an ordered assembly film on the surface of the precious metal thin layer. The ordered assembly film induces the precious metal ions to continue to grow along the {100} crystal plane and the {110} crystal plane to form an oriented coating.

7. The method for preparing a signal connector according to claim 2, characterized in that: After the initial coating is formed, a continuous frequency sweep excitation signal in the range of 10-150kHz is applied to the Fe-Ga-Cu ternary eutectic nanomagnetic layer, a frequency response characteristic curve is obtained through the acoustic signal generated by the Fe-Ga-Cu ternary eutectic nanomagnetic layer, a thickness distribution cloud map of the initial coating is calculated based on the frequency response characteristic curve, and the thickness mean square deviation of each radial section in the thickness distribution cloud map is analyzed to determine the uniformity of the initial coating, including: The Fe-Ga-Cu ternary eutectic nanomagnetostrictive layer is excited by using four groups of orthogonal sweep frequency signals with base frequencies of 17 kHz, 23 kHz, 29 kHz and 37 kHz, respectively, to obtain magnetostrictive response signals at different depths; Calculating the mechanical vibration characteristics of the Fe-Ga-Cu ternary eutectic nanomagnetostrictive layer at different depths according to the phase difference and amplitude change of the magnetostrictive response signal, and generating a frequency response characteristic curve; According to the corresponding relationship between the frequency displacement in the frequency response characteristic curve and the coating thickness, a depth-frequency shift calibration curve is established to calculate the thickness distribution cloud map of the initial coating; The thickness distribution cloud map is divided into a plurality of radial regions with equal angular intervals, and the thickness mean square deviation in each radial region is calculated to generate a coating uniformity distribution map.

8. The method for preparing a signal connector according to claim 7, characterized in that: The method of calculating the mechanical vibration characteristics of the Fe-Ga-Cu ternary eutectic nanomagnetic layer at different depths according to the phase difference and amplitude change of the magnetostrictive response signal to generate a frequency response characteristic curve includes: Performing time-series acquisition of the magnetostrictive response signal of the Fe-Ga-Cu ternary eutectic nanomagnetostrictive layer in the depth direction, and extracting phase difference information and amplitude information at each acquisition moment; Calculate the propagation delay of the acoustic wave at different depths of the Fe-Ga-Cu ternary eutectic nanomagnetic layer according to the phase difference information, and calculate the energy attenuation coefficient of the acoustic wave at different depths of the Fe-Ga-Cu ternary eutectic nanomagnetic layer according to the amplitude information; The propagation delay and the energy attenuation coefficient are combined with the lattice strain coupling coefficients of Fe atoms, Ga atoms and Cu atoms in the Fe-Ga-Cu ternary eutectic nanomagnetic layer, the vibration difference of the Fe-Ga-Cu ternary eutectic nanomagnetic layer on the {100} crystal plane and the {110} crystal plane is calculated, the mass load contribution and stress coupling contribution of the initial coating to the Fe-Ga-Cu ternary eutectic nanomagnetic layer are separated, and the mechanical vibration characteristics of the Fe-Ga-Cu ternary eutectic nanomagnetic layer are obtained; The mechanical vibration characteristics are subjected to Fourier transformation according to the frequency to obtain a frequency response characteristic curve of the Fe-Ga-Cu ternary eutectic nanomagnetic layer.

9. The method for preparing a signal connector according to any one of claims 2 to 8, characterized in that: After determining the uniformity of the initial plating layer, the method for preparing the signal connector further comprises: Determine the weak coating area inside the microhole according to the thickness mean square deviation of each radial section in the thickness distribution cloud map, and divide the weak coating area into a near-hole mouth area, a middle section area, and a hole bottom area according to the depth position of the microhole; An annular anode array is arranged outside the micropore, and an axial electric field gradient is formed in the micropore by adjusting the potential difference of each annular anode, and the axial electric field gradient drives the noble metal ions to migrate from the near-pore-mouth region to the pore-bottom region; Applying an alternating magnetic field along the axial direction of the micropore to the Fe-Ga-Cu ternary eutectic nanomagnetic layer, wherein the frequency of the alternating magnetic field matches the inherent resonance frequency of the Fe-Ga-Cu ternary eutectic nanomagnetic layer, and the phase is 90° ahead of the plating current pulse, and the alternating magnetic field induces a standing wave acoustic field in the micropore; Under the action of the standing wave acoustic field, the noble metal ions form periodically distributed concentration nodes in the micropores, and according to the positional relationship between the concentration nodes and the weak areas of the coating, the frequency of the alternating magnetic field is adjusted to control the deposition of the noble metal ions in the weak areas of the coating; By monitoring the magnetostrictive response signal of the Fe-Ga-Cu ternary eutectic nanomagnetostrictive layer at different depths, it is determined whether the coating thickness in the weak coating area reaches a preset value.

10. The method for preparing a signal connector according to claim 9, characterized in that: After the coating thickness in the weak coating area reaches a preset value, the method for preparing the signal connector further includes: Introducing hydrogen plasma into the micropores at a vacuum degree of 1 Pa, wherein the hydrogen plasma selectively reacts with the amino coordination sites on the surface of the Fe-Ga-Cu ternary eutectic nanomagnetic layer, so that Fe atoms and Ga atoms are peeled off layer by layer from the Fe-Ga-Cu ternary eutectic nanomagnetic layer; Migrating the stripped Fe atoms and Ga atoms into the initial coating through grain boundary diffusion, wherein the Fe atoms and Ga atoms form nano-scale alloy dots at the grain boundaries of the initial coating, and the size of the nano-scale alloy dots is less than 10 nm; During the formation of the nano-scale alloy dots, a continuous frequency sweep signal is applied to the Fe-Ga-Cu ternary eutectic nanomagnetic layer to obtain a resonance spectrum during the attenuation process; The frequency shift and attenuation coefficient in the resonance spectrum are compared with the original spectrum to generate a stress distribution diagram of the micropore inner wall coating and a structural integrity evaluation result.

Images