Preparation method of high-quality connection terminal based on single crystal

Abstract

The invention relates to the technical field of connection terminals, and discloses a preparation method of a high-quality connection terminal based on a single crystal. Single crystal materials such as single crystal copper, single crystal silver and single crystal alloy (such as single crystal gold and silver) are used as main raw materials of the connection terminal for production and manufacturing, and after the materials are processed, precious metal electroplating protection is further carried out according to the use purpose and the practical application of transmitted signals. And finally, the whole finished terminal is subjected to liquid nitrogen subzero treatment, so that the electrical performance of the terminal is further improved, the use requirements of connection terminals for military industry, aerospace, audio and the like are met, and the purposes of optimizing the quality of transmitted audio signals and reducing the transmission distortion of the terminal are achieved. As a scheme for improving the transmission signal quality, the technology can be migrated to more plug terminals for improving the signal quality.

Description

Technical Field

[0001] The invention relates to the technical field of connecting terminals, and in particular to a method for preparing high-quality connecting terminals based on single crystals. Background Art

[0002] In recent years, the purity of single crystal materials has been continuously improved due to the rapid iteration of smelting technology (the current purification technology can reach a purity of more than 99.999998%). At the same time, the number of cross-sectional end grains in the single crystal structure is controlled less and less, and its low distortion and quality advantages as a medium for transmitting signals are becoming more and more obvious. At present, it has been widely used in the field of semiconductors and signal transmission, especially in the military, aerospace and audio fields with strict requirements on signal quality, and has received more and more attention.

[0003] Single crystals have been used as raw materials for wires in many applications in signal transmission. However, the materials used for connecting terminals at both ends of wires in the fields of military, aerospace, audio, etc. are still in the early stage of using polycrystalline or low-purity conventional metals such as silver, phosphor copper, and zinc alloy. The short board effect of connecting wire terminals in signal transmission seriously restricts the upper limit of the quality of the transmitted signal. Therefore, a method for preparing high-quality connecting terminals based on single crystals is proposed. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method for preparing a high-quality connection terminal based on a single crystal to solve the background technical problems.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing a high-quality connection terminal based on a single crystal, comprising the following steps:

[0006] Step 1: Select single crystal copper, single crystal silver or single crystal alloy as the main raw material of the connection terminal, and select the material, purity and number of end grains of the single crystal according to the terminal's demand standard for signal transmission.

[0007] Step 2: Store the high-purity single crystals separately. If the storage time is long, place them on a nylon board or a tempered glass board.

[0008] Step three, cut the single crystal processing raw material into pieces along the plane perpendicular to the crystallization direction, mark the single crystal direction, and obtain a rough round bar of suitable height.

[0009] Step 4: Select the corresponding processing machine according to the shape, length and thickness of the terminal. Before processing, confirm the conduction direction of the core structure and the crystallization direction of the raw material to ensure that the conduction direction of the finished terminal structure is consistent with the crystallization direction of the raw material. Perform precision processing on the single crystal raw material to form the basic shape of the connecting terminal.

[0010] Step 5: During the processing, use impurity-free circulating cooling oil to spray and cool the processed body to avoid oxidation and degeneration of the single crystal and maintain the smoothness of the surface.

[0011] Step six, electroplating the processed connection terminals, mirror polishing before electroplating to ensure that the surface before electroplating is smooth enough and the electroplating is uniform, and the electroplating material can be selected from precious metal materials such as platinum and palladium.

[0012] Step seven: Use nylon material to perform shielding injection molding between the machined single crystal metal parts to ensure stable isolation between the transmission conductors to produce finished connection terminals.

[0013] Preferably, during the processing in step 4, nitrogen is filled to form a moderate anti-oxidation environment, delay the oxidation of the single crystal surface, and reduce the thickness of the oxide film on the conductor surface;

[0014] Preferably, in step five, the surface processing temperature of the connecting terminal is controlled by circulating cooling oil so that the air test around the entire core is within 70 degrees Celsius (the air temperature test at a distance less than 1 mm around the processing body) and the cutting point temperature is within 170 degrees Celsius, ensuring that the temperature of the cutting point and the surrounding area of ​​the processing body does not exceed the set range.

[0015] Preferably, the preparation method further comprises step eight, performing a liquid nitrogen cryogenic treatment on the entire core of the finished terminal to optimize the internal grain boundary arrangement and further improve the electrical performance of the terminal.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention uses single crystal materials such as single crystal copper, single crystal silver, and single crystal alloy (such as single crystal gold and silver) as the main raw materials for the connection terminal for production and manufacturing, and after the material processing is completed, further precious metal electroplating protection is performed depending on the purpose of use and the actual application of the transmitted signal. Finally, the entire finished terminal is subjected to liquid nitrogen deep freezing treatment to further improve its electrical performance, meet the use requirements of connection terminals such as military, aerospace, and audio, and achieve the purpose of optimizing the quality of transmitted audio signals and reducing terminal transmission distortion; as a solution to improve the quality of transmitted signals, this technology can also be migrated to more plug terminals for improving signal quality.

[0018] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1The present invention is a flowchart of the steps of the method for preparing a high-quality connection terminal based on a single crystal;

[0020] Figure 2 This is a schematic diagram of the pin core of a universal LEMO two-pin aviation plug;

[0021] Figure 3 for Figure 2 Schematic diagram of the disassembly diagram;

[0022] Figure 4 This is a schematic diagram of the pin core of the new material single crystal copper gold-plated LEMO double-pin aviation plug;

[0023] Figure 5 This is a schematic diagram of the 4.4mm plug and the core in the audio field. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this technical field without creative work are within the scope of protection of the present invention.

[0025] See also Figure 1-5 The present invention provides a method for preparing a high-quality connection terminal based on a single crystal, which specifically includes the following implementation steps:

[0026] Step 1:

[0027] Material selection: According to the requirements, single crystal materials such as single crystal copper, single crystal silver, single crystal alloy (such as single crystal gold and silver) are selected as the main raw materials for the connecting terminals; this embodiment selects high-purity single crystal copper as the main raw material.

[0028] Purity and telomere control: Select the material, purity and telomere number of the single crystal according to the terminal's signal transmission requirements.

[0029] Step 2:

[0030] Storage and isolation: High-purity single-crystal copper should be stored separately from other metal products to avoid atomic exchange at the contact surface between metals that affects the purity of the material.

[0031] Storage platform selection: When storing for a long time, use non-metallic materials such as nylon plates and tempered glass as storage platforms to reduce contamination of the single crystal.

[0032] Step 3:

[0033] Cutting direction: Cut the whole material along the plane perpendicular to the crystallization direction to ensure that the crystallization direction of the round bar blank after cutting is consistent with the conduction direction of the final terminal.

[0034] Marking and recording: Mark the single crystal direction on the rough round bar after cutting for reference in subsequent processing.

[0035] Step 4:

[0036] Machine selection: Select the appropriate processing machine for precision processing based on factors such as the shape, length, and thickness of the terminal.

[0037] Confirmation of conduction direction: Before processing, confirm that the conduction direction of the conductor structure is consistent with the crystallization direction of the raw material to ensure the conduction performance of the finished terminal structure.

[0038] Precision machining: Through precision machining, the basic shape of the connection terminal is formed, such as BNC / LEMO aviation plug, 3.5mm / 4.4mm / 6.35mm / Lotus plug / xlr and headphone pin core, etc.

[0039] Nitrogen filling: During the processing, nitrogen is filled appropriately to form a moderate anti-oxidation environment to delay the oxidation of the single crystal surface.

[0040] Oxide film control: By controlling the amount of nitrogen charged, the thickness of the oxide film on the conductor surface can be reduced and the conductivity of the terminal can be improved.

[0041] Step 5:

[0042] Cooling oil selection: Use brand new circulating cooling oil to spray and cool the processing body to avoid the cooling oil from contaminating the processing single crystal consumables.

[0043] Temperature control: Ensure that the temperature during the cooling process is controlled within an appropriate range to avoid adverse effects on the performance of the single crystal.

[0044] Smoothness maintenance: Through appropriate processing parameters and processes, the smoothness of the surface is maintained to improve the contact performance and stability of the terminal.

[0045] Step 6:

[0046] Polishing: Before electroplating, the finished connecting terminals are mirror polished to ensure that the surface is smooth enough before electroplating.

[0047] Selection of electroplating materials: Select precious metal materials such as platinum and palladium for electroplating to improve the conductivity and corrosion resistance of the terminals.

[0048] Electroplating uniformity: Ensure that the electroplating process is uniform to avoid problems such as uneven thickness or shedding of the electroplating layer.

[0049] Step 7:

[0050] Injection molding material selection: Use nylon and other materials to perform shielding injection molding between machined single crystal metal parts to ensure stable isolation between transmission cores.

[0051] Injection molding process: Control parameters such as temperature, pressure and speed during the injection molding process to ensure the injection molding quality and terminal stability.

[0052] Step 8: Liquid nitrogen cryogenic treatment: The finished terminal is subjected to liquid nitrogen cryogenic treatment to optimize the internal grain boundary arrangement and further improve the electrical performance of the terminal. Specific embodiment one:

[0054] Taking the specific LEMO double-pin aviation plug as an example, the technical solution is further described in detail. Figure 2-4 As shown, the reference numeral 1 is the nylon injection-molded isolation part, the reference numeral 2 is the pin guide core, and the reference numeral 3 is the single crystal copper raw material to be processed of the pin guide core. Figure 4 The single crystal direction of the positive pin in the middle is downward, and the single crystal direction of the negative terminal pin is upward.

[0055] Step 1:

[0056] Based on the LEMO two-pin aviation plug, considering the maximum diameter of the finished pin core section is 1.60mm, for pin processing;

[0057] The rough diameter of the raw material to be processed usually maintains a cutting margin of 0.1mm or more with the finished core of the needle-shaped structure, so the raw material to be processed can be a single crystal copper raw material with a diameter of 1.80mm or more;

[0058] In addition, considering the transmission distortion standard requirements and the actual processing budget, single crystal copper with a cross-sectional end grain number of 4-6, a diameter of 1.80mm, and a purity of 99.99998% was finally selected as the raw material for processing. The crystallization direction of the single crystal copper raw material was marked before processing.

[0059] Step 2:

[0060] The directional issues that need to be considered for the needle core made of single crystal copper are: Figure 4 Taking the finished product of the single crystal pin as an example, according to the division of labor of positive and negative pole conduction that the needle core is responsible for, the core guide needle for the positive end is processed into the finished product by a Swiss machine according to the crystallization direction in the figure, and the core guide needle for the negative end is processed into the finished product by a Swiss machine according to the crystallization example direction of the negative end in the figure; it can be seen in the figure that the crystallization directions of the two core guide needles responsible for different electrodes injected in the same needle core are opposite.

[0061] Step 3:

[0062] After the core guide pin is processed by the Swiss machine, remove the rough blank of the pin and polish it with a wool wheel and 500 mesh polishing hard wax (polish lightly to avoid deformation, and do not over-polish to make it thinner and increase manufacturing errors). After wiping it clean, prepare for electroplating immediately to prevent the formation of an oxide film again due to being left for too long.

[0063] Step 4:

[0064] The electroplating uses electrolytic gold plating. Considering durability and transmission signal quality, the electroplating thickness of the conductor is designed to be around 10μ gold layer. After the gold plating is completed, the conductor needle part is completed (the surface layer can also be plated with a combination of silver and rhodium according to the electroplating thickness suitable for plug-in).

[0065] Step 5:

[0066] Finally, place the core guide pin into the pin injection mold for the final shielding injection molding process. Nylon is preferred as the injection molding material. After the injection molding is completed, the finished product is fully manufactured and can be put into use.

[0067] Step 6:

[0068] According to the performance standards and budget, the finished terminals are further subjected to liquid nitrogen cryogenic treatment as needed. It is advisable to directly put the connected terminal parts into the liquid nitrogen tank for 10-15 minutes to optimize the internal grain boundary arrangement and further improve the electrical performance of the terminals.

[0069] Embodiment 2:

[0070] For terminals with different electrode transmission structure paths (such as digital / analog positive and negative electrodes of coaxial terminals, usually with thin inner needles and special outer shapes), it is possible to consider using single crystal materials of the same material but different purities on the same transmission plug for matching, or to use single crystal materials of different materials for assembly configuration for balance, such as Figure 5 The 4.4mm audio plug and the center core are shown. In this plug, the center transmission core has the longest and thinnest structure, resulting in the longest signal transmission path. Therefore, the guide core of the innermost transmission needle can be replaced with a 7n single crystal copper-silver alloy mixture (with faster signal transmission speed), while the other three levels use a combination of single crystal copper materials to achieve relatively balanced signal transmission conditions.

Claims

1. A method for preparing a high-quality connection terminal based on a single crystal, characterized in that: The following steps are involved: Step 1: Select single crystal copper, single crystal silver or single crystal alloy as the main raw material of the connection terminal, and select the material, purity and number of end grains of the single crystal according to the terminal's demand standard for signal transmission. Step 2: Store the high-purity single crystals separately. If the storage time is long, place them on a nylon board or a tempered glass board. Step three, cut the single crystal processing raw material into pieces along the plane perpendicular to the crystallization direction, mark the single crystal direction, and obtain a rough round bar of suitable height. Step 4: Select the corresponding processing machine according to the shape, length and thickness of the terminal. Before processing, confirm the conduction direction of the core structure and the crystallization direction of the raw material to ensure that the conduction direction of the finished terminal structure is consistent with the crystallization direction of the raw material. Perform precision processing on the single crystal raw material to form the basic shape of the connecting terminal. Step 5: During the processing, use impurity-free circulating cooling oil to spray and cool the processed body to avoid oxidation and degeneration of the single crystal and maintain the smoothness of the surface. Step six, electroplating the processed connection terminals, mirror polishing before electroplating to ensure that the surface before electroplating is smooth enough and the electroplating is uniform, and the electroplating material can be selected from precious metal materials such as platinum and palladium. Step seven: Use nylon material to perform shielding injection molding between the machined single crystal metal parts to ensure stable isolation between the transmission conductors to produce finished connection terminals.

2. A method for preparing a high-quality connection terminal based on a single crystal according to claim 1, characterized in that: During the processing in step 4, nitrogen is filled to form a moderate anti-oxidation environment, delay the oxidation of the single crystal surface, and reduce the thickness of the oxide film on the conductor surface.

3. The method for preparing a high-quality connection terminal based on a single crystal according to claim 1, characterized in that: In step five, the surface processing temperature of the connecting terminal is controlled by circulating cooling oil to be within 70 degrees Celsius in the air test around the entire core (air temperature test less than 1mm around the processing body) and the cutting point temperature is within 170 degrees Celsius to ensure that the cutting point and the surrounding temperature of the processing body do not exceed the set range.

4. The method for preparing a high-quality connection terminal based on a single crystal according to claim 1, characterized in that: The preparation method also includes step eight, performing a liquid nitrogen deep cryogenic treatment on the entire core of the finished terminal to optimize the internal grain boundary arrangement and further improve the electrical performance of the terminal.

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