Preparation method of high-temperature insulated wire and inductor

Abstract

The invention provides a preparation method of a high-temperature insulated wire and an inductor. The preparation method comprises the step of sequentially plating the Ni intermediate layer, the ZrO2 insulating layer and the Ta2O5 insulating layer on a pretreated copper wire to obtain the high-temperature insulated wire. The magnetron sputtering method is adopted, the copper wire is plated with Ni to serve as the middle layer, then the ZrO2 thin film and the Ta2O5 thin film are sequentially plated to serve as the insulating layers, and the prepared wire has good high-temperature insulating performance and good bending resistance; the problem that the performance of a traditional wire is reduced or fails when the temperature is higher than 260 DEG C and the problem that the performance of the traditional wire cannot be fully exerted when the traditional wire is annealed at high temperature are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic wires and relates to a preparation method of a high-temperature insulated wire and an inductor. Background Art

[0002] Electromagnetic wire is an insulated wire used to make coils or windings in electrical products. The structure of electromagnetic wire generally includes a conductive core and an electrical insulation layer covering the conductive core. Winding a coil on a ferrite can form a winding inductor. Coils are also used in fields such as one-piece molded inductors and thin-film inductors. In order to ensure good bending resistance, the commonly used coils at present often use an organic insulating layer coated on the surface of the core, which will cause the coil to be unable to withstand high temperatures. Generally, when the temperature exceeds 260°C, the performance will decline or even fail completely.

[0003] CN111883289A discloses an insulated wire, comprising a wire core and a metal oxide insulating layer coated on the outer periphery of the wire core; or comprising a wire core and an intermediate layer and a metal oxide insulating layer sequentially coated on the outer periphery of the wire core; the material of the wire core comprises Cu, Al, Ag or their alloys; the intermediate layer comprises Ni, Nb, Cr, Fe, Al, Zr, Ti, V, W, Mo, Cu simple substance or an alloy containing one or more of the above metal elements, and the intermediate layer is different from the material of the wire core; the metal oxide insulating layer comprises oxides of one or more metal elements among Ni, Nb, Cr, Fe, Al, Zr, Ti, V, W, Mo, Cu. However, the preparation method of the insulated wire prepared in the invention is relatively complicated.

[0004] CN112185628A discloses a semi-finished high-temperature insulated wire, comprising a wire core and a sol-gel composite coating coated on the periphery of the wire core, wherein the sol-gel composite coating comprises a gel matrix modified by polyvinyl alcohol and an inorganic filler dispersed in the gel matrix modified by polyvinyl alcohol, and the gel matrix modified by polyvinyl alcohol comprises a gel matrix body and polyvinyl alcohol connected to the gel matrix body, and the gel matrix body comprises a three-dimensional network structure repeatedly composed of -Si-O-Si- and / or -MOM-, wherein M is a metal atom. The semi-finished high-temperature insulated wire has good insulation performance and bending resistance by forming a sol-gel composite coating on the periphery of the wire core, and can meet the winding requirements of various coils and windings. However, the entire preparation process is relatively complicated, with many influencing factors, which is not conducive to controlling product uniformity, is time-consuming, and has low production efficiency. At the same time, this method designs multi-step chemical reactions and metal solutions, which are easy to pollute the environment.

[0005] CN103700469A discloses a coil for a chip inductor, wherein the coil in the patent includes: a coil layer containing a conductive metal, an insulating layer around the coil layer, and a bonding layer around the insulating layer. The coil of the patent invention can prevent deformation caused by high-temperature magnetic resin filling or high-temperature curing when the coil is applied to the inductor, but the polyimide layer between the insulating layer and the bonding layer in the patent will affect the high-temperature insulation performance of the entire coil.

[0006] Traditional one-piece molded inductors are made by hot pressing or cold pressing under high pressure, and need to be annealed at a high temperature to remove stress. Therefore, the preparation of a wire with high-temperature insulation and good bending resistance has gradually become the focus of research and application in recent years. Summary of the invention

[0007] In view of the shortcomings of the prior art, the object of the present invention is to provide a method for preparing a high-temperature insulated wire and an inductor.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] One of the purposes of the present invention is to provide a method for preparing a high-temperature insulated wire, the method comprising:

[0010] The high temperature insulated wire is obtained by sequentially plating a Ni intermediate layer, a ZrO2 insulating layer and a Ta2O5 insulating layer on the pretreated copper wire.

[0011] The present invention first plates a Ni film as an intermediate layer on the surface of the copper wire by magnetron sputtering, and then plates a ZrO2 film and a Ta2O5 film as an insulating layer in sequence on this basis. The Ni film as the intermediate layer has a lattice constant close to that of copper, so it can effectively regulate the expansion of the insulating layer as the temperature rises. The ZrO2 film on the insulating layer not only has a high melting point and good high-temperature chemical stability, but also can provide a good substrate for the outermost Ta2O5 film to facilitate the combination of the Ta2O5 film and the coil. The Ta2O5 film has a high dielectric constant, which can improve the dielectric strength of the entire coil and withstand a higher breakdown voltage.

[0012] As a preferred technical solution of the present invention, the pretreatment method comprises:

[0013] The copper wire is sequentially subjected to a first ultrasonic cleaning, an acid cleaning, a second ultrasonic cleaning and drying to complete the pretreatment of the copper wire.

[0014] As a preferred technical solution of the present invention, the first ultrasonic cleaning is carried out in acetone.

[0015] Preferably, the first ultrasonic cleaning time is 5 to 10 minutes, wherein the time may be 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] Preferably, the pickling is carried out in a sulfuric acid solution.

[0017] Preferably, the concentration of the sulfuric acid solution is 5-10%, wherein the concentration may be 5%, 6%, 7%, 8%, 9% or 10%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the pickling time is 5 to 8 minutes, wherein the time can be 5 minutes, 6 minutes, 7 minutes or 8 minutes, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] Preferably, the second ultrasonic cleaning comprises: sequentially performing deionized water ultrasonic cleaning and acetone ultrasonic cleaning.

[0020] Preferably, the time for ultrasonic cleaning with deionized water is 10 to 15 minutes, wherein the time can be 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes or 15 minutes, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the acetone ultrasonic cleaning time is 5 to 10 minutes, wherein the time can be 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes or 10 minutes, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] Preferably, the drying temperature is 60-100°C, wherein the temperature may be 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, 95°C or 100°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] As a preferred technical solution of the present invention, the method for plating the Ni intermediate layer includes: sputtering Ni on the pretreated copper wire.

[0024] Preferably, the Ni sputtering is performed in a sputtering chamber provided with a magnetron sputtering apparatus, and a Ni target is mounted on a magnetron sputtering target holder.

[0025] As a preferred technical solution of the present invention, the background vacuum degree of the sputtering chamber is 1×10 -3 ~3×10-3 Pa, wherein the vacuum degree may be 1×10 -3 Pa, 2×10 -3 Pa or 3×10 -3 Pa, etc., but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] Preferably, the Ni sputtering atmosphere includes argon.

[0027] Preferably, the pressure of the Ni sputtering is 0.3-0.6 Pa, wherein the pressure may be 0.3 Pa, 0.4 Pa, 0.5 Pa or 0.6 Pa, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the Ni sputtering time is 10 to 20 min, wherein the time can be 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min or 20 min, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] Preferably, the purity of the Ni target is ≥99%, wherein the purity may be 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] Preferably, the Ni sputtering power is 1.5-1.8 kW, wherein the power may be 1.5 kW, 1.6 kW, 1.7 kW or 1.8 kW, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] In the present invention, if the Ni sputtering power is too high, the deposition rate will be too fast, the surface roughness of the film will increase, and its bonding ability with the ZrO2 coating will be affected. If the sputtering power is too low, the energy of the sputtered atoms reaching the Cu wire will be low, so that Ni cannot be completely and evenly covered on the Cu wire, which will further weaken its ability to adjust the expansion with the increase of temperature.

[0032] Preferably, the Ni sputtering temperature is 150-200°C, wherein the temperature may be 150°C, 160°C, 170°C, 180°C, 190°C or 200°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0033] In the present invention, the Ni sputtering temperature is set between 150 and 200°C. If the Ni sputtering temperature is too high, the growth kinetic energy of the atoms will increase, especially for the metal atom Ni, which will make it more solution-crystallized and the grain volume will increase, and finally the roughness of the film surface will increase, affecting its bonding ability with the ZrO2 coating. If the Ni sputtering temperature is too low, the sputtered atoms will quickly lose kinetic energy and quickly condense on the surface, causing the film to easily form an amorphous structure and more defects.

[0034] As a preferred technical solution of the present invention, the method for plating the ZrO2 insulating layer includes: sputtering ZrO2 on the copper wire after plating the Ni intermediate layer.

[0035] Preferably, the ZrO2 sputtering is performed in a sputtering chamber provided with a magnetron sputtering apparatus, and the ZrO2 target is mounted on a magnetron sputtering target holder.

[0036] As a preferred technical solution of the present invention, the background vacuum degree of the sputtering chamber is 4×10 -4 ~6×10 -4 Pa, wherein the vacuum degree may be 4×10 -4 Pa, 5×10 -4 Pa or 6×10 -4 Pa, etc., but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] Preferably, the ZrO2 sputtering atmosphere includes argon.

[0038] Preferably, the ZrO2 sputtering pressure is 0.5-0.8 Pa, wherein the pressure may be 0.5 Pa, 0.6 Pa, 0.7 Pa or 0.8 Pa, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] Preferably, the ZrO2 sputtering time is 0.5 to 1.5 h, wherein the time may be 0.5 h, 0.6 h, 0.7 h, 0.8 h, 0.9 h, 1.0 h, 1.1 h, 1.2 h, 1.3 h, 1.4 h or 1.5 h, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] Preferably, the purity of the ZrO2 target material is ≥99.9%, wherein the purity may be 99.9%, 99.95%, 99.99% or 100%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] Preferably, the ZrO2 sputtering power is 80-120 W, wherein the power may be 80 W, 85 W, 90 W, 95 W, 100 W, 105 W, 110 W, 115 W or 120 W, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0042] In the present invention, if the power of ZrO2 sputtering is too high, the crystal structure of the ZrO2 film will be changed, and the original nanocrystalline structure film will be transformed into a columnar crystal structure film, and the latter has the disadvantages of poor elastic recovery and large plastic deformation compared with the former, so that the ZrO2 coating is easy to deform and break when subjected to external force. If the power of ZrO2 sputtering is too low, it will lead to the inability to form a dense and uniform ZrO2 coating, so that the Ta2O5 coating will directly contact the Ni layer, and the Ta2O5 coating will easily fall off.

[0043] Preferably, the ZrO2 sputtering temperature is 15-25°C, wherein the temperature may be 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C or 25°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0044] As a preferred technical solution of the present invention, the method for plating a Ta2O5 insulating layer includes: sputtering Ta2O5 on the copper wire after plating a ZrO2 insulating layer.

[0045] Preferably, the Ta2O5 sputtering is carried out in a sputtering chamber provided with a magnetron sputtering apparatus, and a Ta2O5 target is mounted on a magnetron sputtering target holder.

[0046] As a preferred technical solution of the present invention, the background vacuum degree of the sputtering chamber is 3×10 -5 ~6×10 -5 Pa, wherein the vacuum degree may be 3×10 -5 Pa, 4×10 -5 Pa, 5×10 -5 Pa or 6×10 -5 Pa, etc., but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0047] Preferably, the atmosphere for sputtering Ta2O5 includes argon and / or oxygen, preferably argon and oxygen.

[0048] Preferably, the flow ratio of argon and oxygen is 3:1 to 5:1, wherein the flow ratio may be 3:1, 4:1 or 5:1, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0049] Argon in the present invention is sputtering gas, and oxygen is reaction gas, Ta2O5 is easy to lose oxygen when sputtering and depositing on sample due to the property of its material itself, so it is necessary to pass through appropriate oxygen to make up for the lost oxygen during deposition, so as to keep the composition of coating in accordance with stoichiometric ratio. The flow rate of oxygen passed through simultaneously cannot be too high, if the flow rate ratio of argon and oxygen is too low, the probability of collision between oxygen molecules and high-energy argon particles in vacuum chamber increases, objectively can reduce incident particle energy, make the total energy of particles bombarding target material reduce, cause sputtering yield to reduce, deposition rate to reduce, finally cause Ta2O5 coating thickness and compactness not as expected, affect the insulation of sample. In a word, the flow rate ratio of argon and oxygen in the present invention is too high or too low and can affect the quality of Ta2O5 coating, and then cause the insulation performance of sample to decrease.

[0050] Preferably, the sputtering pressure of Ta2O5 is 0.5-0.8Pa, wherein the pressure may be 0.5Pa, 0.6Pa, 0.7Pa or 0.8Pa, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0051] Preferably, the Ta2O5 sputtering time is 0.5 to 2.5 h, wherein the time may be 0.5 h, 0.8 h, 1.0 h, 1.2 h, 1.4 h, 1.6 h, 1.8 h, 2.0 h, 2.2 h, 2.4 h or 2.5 h, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0052] Preferably, the purity of the Ta2O5 target material is ≥99.9%, wherein the purity may be 99.9%, 99.95%, 99.99% or 100%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0053] Preferably, the Ta2O5 sputtering power is 100-140W, wherein the power may be 100W, 105W, 110W, 115W, 120W, 125W, 130W, 135W or 140W, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0054] Preferably, the sputtering temperature of Ta2O5 is 15-25°C, wherein the temperature can be 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C or 25°C, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0055] A second object of the present invention is to provide an inductor, wherein the inductor comprises a high-temperature insulated wire, and the high-temperature insulated wire is prepared by the preparation method as described in the first object.

[0056] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] (1) The present invention adopts magnetron sputtering method to plate Ni as an intermediate layer on the copper wire, and then sequentially plate ZrO2 film and Ta2O5 film as insulating layers. The prepared wire has good high-temperature insulation performance and good bending resistance, which solves the problem that the performance of traditional wires decreases or fails when the temperature is higher than 260°C and the problem that the performance of traditional wires cannot be fully exerted due to annealing at high temperature;

[0059] (2) The magnetron sputtering method used in the wire preparation process of the present invention can effectively control the thickness of the coating, accelerate the deposition speed, and achieve a dense and uniform film formation effect;

[0060] (3) The magnetron sputtering method used in the preparation method of the present invention can be used for mass production of high-temperature insulated wires and is environmentally friendly. DETAILED DESCRIPTION

[0061] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0062] Example 1

[0063] The present embodiment provides a method for preparing a high-temperature insulated wire, the method comprising: sequentially plating a Ni intermediate layer, a ZrO2 insulating layer and a Ta2O5 insulating layer on a pretreated copper wire to obtain the high-temperature insulated wire.

[0064] The specific steps are as follows:

[0065] (1) Pretreatment of copper wire: A copper wire with a diameter of 0.9 mm was first ultrasonically cleaned in acetone for 8 min; then, it was pickled in a 7% sulfuric acid solution for 6 min; after pickling, it was ultrasonically cleaned with deionized water and acetone for 12 min and 8 min, respectively; after cleaning, it was quickly dried at 80°C;

[0066] (2) Ni plating intermediate layer: The pretreated copper wire is placed in the sputtering chamber of the magnetron sputtering instrument, and a Ni target with a purity of 99% is installed on the magnetron sputtering target holder; the sputtering chamber is closed and evacuated to a background vacuum of 2×10 -3 Pa, then argon gas is introduced into the sputtering chamber to make the internal pressure reach 0.4Pa; the copper wire is sputtered under the conditions of sputtering power of 1.6kW, sputtering temperature of 180℃ and sputtering time of 10min; after sputtering, the internal pressure of the sputtering chamber reaches one atmosphere, the sputtering chamber door is opened and the copper wire is taken out;

[0067] (3) Plating ZrO2 insulating layer: Place the copper wire after Ni plating into the sputtering chamber of the magnetron sputtering instrument, and install the ZrO2 target with a purity of 99.9% on the magnetron sputtering target holder; close the sputtering chamber and evacuate it so that the background vacuum degree of the sputtering chamber is 5×10 -4 Pa; then, argon gas is introduced into the sputtering chamber to make the internal pressure reach 0.7Pa; the sample is sputtered under the conditions of sputtering power of 100W, sputtering temperature of room temperature, and sputtering time of 1h; after the sputtering is completed, the internal pressure of the sputtering chamber reaches one atmosphere, the sputtering chamber door is opened, and the sample is taken out;

[0068] (4) Plating Ta2O5 insulating layer: Place the copper wire that has been plated with ZrO2 into the sputtering chamber of the magnetron sputtering instrument, and install the Ta2O5 target with a purity of 99.9% on the magnetron sputtering target holder; close the sputtering chamber and evacuate it so that the background vacuum degree of the sputtering chamber is 4×10 -5 Pa; introducing argon and oxygen into the sputtering chamber, the flow ratio of argon and oxygen is 4:1, and the internal air pressure reaches 0.6Pa; sputtering the sample under the conditions of a sputtering power of 110W and a sputtering temperature of room temperature; and a sputtering time of 1.5h. After the sputtering is completed, the internal air pressure of the sputtering chamber reaches one atmosphere, the sputtering chamber door is opened, and the sample is taken out to obtain the high-temperature insulated wire.

[0069] Example 2

[0070] In this embodiment, except that the sputtering power in step (3) is replaced by 80 W and the sputtering time is replaced by 0.5 h, other conditions are the same as those in embodiment 1.

[0071] Example 3

[0072] In this embodiment, except that the sputtering power in step (3) is replaced with 130 W, other conditions are the same as those in embodiment 1.

[0073] Example 4

[0074] In this embodiment, except that the sputtering time in step (3) is replaced with 2 hours, other conditions are the same as those in embodiment 1.

[0075] Example 5

[0076] In this embodiment, except that the sputtering time in step (4) is replaced with 2.5 hours, other conditions are the same as those in embodiment 1.

[0077] Example 6

[0078] In this embodiment, except that the sputtering time in step (4) is replaced with 3 hours, other conditions are the same as those in embodiment 1.

[0079] Example 7

[0080] In this embodiment, except that the flow ratio of argon to oxygen in step (4) is replaced with 5:1, other conditions are the same as those in embodiment 1.

[0081] Example 8

[0082] In this embodiment, except that the flow ratio of argon and oxygen in step (4) is replaced with 2:1, other conditions are the same as those in embodiment 1.

[0083] Example 9

[0084] In this embodiment, except that the flow ratio of argon to oxygen in step (4) is replaced with 6:1, other conditions are the same as those in embodiment 1.

[0085] Comparative Example 1

[0086] In this comparative example, except that the magnetron sputtering of Ni in the intermediate layer in step (2) is not performed, and the ZrO2 and Ta2O5 insulating layers are directly sputtered on the copper wire in sequence, other conditions are the same as those in Example 1.

[0087] Comparative Example 2

[0088] In this comparative example, except that the magnetron sputtering of ZrO2 as the insulating layer in step (3) is not performed, and the sputtering of Ta2O5 as the insulating layer is directly performed on the copper wire after Ni plating, other conditions are the same as those in Example 1.

[0089] Comparative Example 3

[0090] In this comparative example, except that the magnetron sputtering of Ta2O5 on the insulating layer in step (4) is not performed, other conditions are the same as those in Example 1.

[0091] The wires prepared in Examples 1-9 and Comparative Examples 1-3 were tested for breakdown strength and bending resistance. The test results are shown in Table 1.

[0092] The method for testing the breakdown strength includes: testing the breakdown voltage of the coil at room temperature and high temperature (500° C.) according to the national standard GB / T4074.5 for testing the performance of enameled wires.

[0093] Bending resistance test: bend the sample 90° and then return it to its original state. Repeat this process 30 times and then use 3M tape to conduct a qualitative test of the bonding strength to see if the coating has fallen off.

[0094] Table 1

[0095] Breakdown voltage at room temperature(V) High temperature breakdown voltage(V) Bending resistance results Example 1 120 80 Not falling off Example 2 100 60 Not falling off Example 3 -- -- Shedding Example 4 80 60 Not falling off Example 5 120 80 Not falling off Example 6 120 80 Not falling off Example 7 100 60 Not falling off Example 8 80 40 Not falling off Example 9 60 20 Not falling off Comparative Example 1 120 60 Not falling off Comparative Example 2 -- -- Shedding Comparative Example 3 80 40 Not falling off

[0096] It can be seen from the above table that the normal temperature breakdown voltage of the wires prepared in Examples 1, 2, 5 and 7 of the present invention is ≥100V, and the high temperature breakdown voltage is ≥60V, which proves that the conductor has good high temperature insulation ability. At the same time, from the results of the bending resistance test, the wire prepared by the present invention has good bending resistance.

[0097] By comparing Example 3 with Example 1, it can be seen that the sputtering power of Example 3 is too high, which will change the crystal structure of the ZrO2 film during the deposition process, transforming the original nanocrystalline structure film into a columnar crystal structure film. The columnar crystal structure film has the disadvantages of poor elastic recovery ability and large plastic deformation compared to the nanocrystalline structure film, which causes the sample prepared in Example 3 to have the problem of coating falling off after bending.

[0098] By comparing Example 4 with Example 1, it can be seen that the sputtering time of Example 4 is too long, resulting in the problem of increased surface roughness during the deposition process, which makes the bonding between the Ta2O5 coating and the ZrO2 coating not as tight as that in Example 1, thereby causing the sample prepared in Example 4 to have a decreased ability to withstand breakdown voltage.

[0099] Comparison between Example 6 and Example 1 shows that the sputtering time of Example 6 is too long, which will also lead to the problem of increased surface roughness during the deposition process, but since the Ta2O5 coating is the outermost layer, the impact on the breakdown voltage resistance of the sample is relatively small. On the other hand, according to the test results of its breakdown voltage, the breakdown voltage resistance of Example 6 is not better than that of Example 1, so from the perspective of saving cost and time, it is not necessary to increase the sputtering time to 3h.

[0100] Comparison between Examples 8-9 and Example 1 shows that the oxygen flow rate of Example 8 is increased relative to that of Example 1, which increases the probability of collision between oxygen molecules and high-energy argon particles in the vacuum chamber, objectively reduces the energy of the incident particles, reduces the total energy of the particles bombarding the target, and leads to a reduction in sputtering yield and deposition rate, which ultimately leads to the thickness and density of the Ta2O5 coating being not as expected, affecting the insulation of the final sample, and the ability of the sample to withstand breakdown voltage will also decrease. The flow rate ratio of argon and oxygen in Example 9 is increased relative to Example 1, that is, the flow rate of oxygen is reduced, which makes it impossible to increase enough oxygen elements in the deposition process to make up for the oxygen lost by Ta2O5 during the sputtering process, and it is impossible to keep the composition of the coating in accordance with the stoichiometric ratio, which ultimately reduces the insulation of the sample and deteriorates the ability to withstand breakdown voltage.

[0101] Compared with Example 1, Comparative Example 1 lacks the magnetron sputtering of Ni in the intermediate layer, so that the bonding tightness between the copper wire and the insulating layer is not high after high-temperature treatment, which leads to a decrease in the high-temperature breakdown voltage.

[0102] Comparative Example 2 does not have a ZrO2 layer between the intermediate Ni layer and the insulating Ta2O5 layer compared to Example 1. Since the wettability and bonding degree of Ta2O5 with Cu or Ni are relatively poor, it is very easy for Ta2O5 to be attached to the intermediate Ni layer and fall off due to external force.

[0103] Compared with Example 1, Comparative Example 3 does not have the outermost Ta2O5 insulating layer, so that the advantage of withstanding a higher breakdown voltage cannot be fully utilized, resulting in poor high-temperature insulation performance.

[0104] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a high-temperature insulated wire, characterized in that: The preparation method comprises: The high temperature insulated wire is obtained by sequentially plating a Ni intermediate layer, a ZrO2 insulating layer and a Ta2O5 insulating layer on the pretreated copper wire.

2. The preparation method according to claim 1, characterized in that: The pretreatment method comprises: The copper wire is sequentially subjected to a first ultrasonic cleaning, an acid cleaning, a second ultrasonic cleaning and drying to complete the pretreatment of the copper wire.

3. The preparation method according to claim 2, characterized in that: The first ultrasonic cleaning is carried out in acetone; Preferably, the first ultrasonic cleaning time is 5 to 10 minutes; Preferably, the pickling is carried out in a sulfuric acid solution; Preferably, the concentration of the sulfuric acid solution is 5-10%; Preferably, the pickling time is 5 to 8 minutes; Preferably, the second ultrasonic cleaning comprises: sequentially performing deionized water ultrasonic cleaning and acetone ultrasonic cleaning; Preferably, the deionized water ultrasonic cleaning time is 10 to 15 minutes; Preferably, the acetone ultrasonic cleaning time is 5 to 10 minutes; Preferably, the drying temperature is 60-100°C.

4. The preparation method according to any one of claims 1 to 3, characterized in that The method for plating the Ni intermediate layer comprises: performing Ni sputtering on the pretreated copper wire; Preferably, the Ni sputtering is performed in a sputtering chamber provided with a magnetron sputtering apparatus, and a Ni target is mounted on a magnetron sputtering target holder.

5. The preparation method according to claim 4, characterized in that: The background vacuum of the sputtering chamber is 1×10 -3 ~3×10 -3 Pa; Preferably, the Ni sputtering atmosphere includes argon; Preferably, the pressure of the Ni sputtering is 0.3-0.6 Pa; Preferably, the Ni sputtering time is 10 to 20 minutes; Preferably, the purity of the Ni target is ≥99%; Preferably, the Ni sputtering power is 1.5-1.8 kW; Preferably, the Ni sputtering temperature is 150-200°C.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The method for plating a ZrO2 insulating layer comprises: performing ZrO2 sputtering on the copper wire after plating a Ni intermediate layer; Preferably, the ZrO2 sputtering is performed in a sputtering chamber provided with a magnetron sputtering apparatus, and the ZrO2 target is mounted on a magnetron sputtering target holder.

7. The preparation method according to claim 6, characterized in that: The background vacuum of the sputtering chamber is 4×10 -4 ~6×10 -4 Pa; Preferably, the atmosphere for the ZrO2 sputtering includes argon; Preferably, the ZrO2 sputtering pressure is 0.5-0.8 Pa; Preferably, the ZrO2 sputtering time is 0.5 to 1.5 h; Preferably, the purity of the ZrO2 target material is ≥99.9%; Preferably, the power of the ZrO2 sputtering is 80 to 120 W; Preferably, the ZrO2 sputtering temperature is 15-25°C.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The method for coating a Ta2O5 insulating layer comprises: sputtering Ta2O5 on a copper wire coated with a ZrO2 insulating layer; Preferably, the Ta2O5 sputtering is carried out in a sputtering chamber provided with a magnetron sputtering apparatus, and a Ta2O5 target is mounted on a magnetron sputtering target holder.

9. The preparation method according to claim 8, characterized in that: The background vacuum of the sputtering chamber is 3×10 -5 ~6×10 -5 Pa; Preferably, the atmosphere for sputtering Ta2O5 comprises argon and / or oxygen, preferably argon and oxygen; Preferably, the flow ratio of argon to oxygen is 3:1 to 5:1; Preferably, the pressure of the Ta2O5 sputtering is 0.5-0.8 Pa; Preferably, the Ta2O5 sputtering time is 0.5 to 2.5 h; Preferably, the purity of the Ta2O5 target material is ≥99.9%; Preferably, the power of the Ta2O5 sputtering is 100-140W; Preferably, the Ta2O5 sputtering temperature is 15-25°C.

10. An inductor, characterized in that: The inductor comprises a high-temperature insulated wire, and the high-temperature insulated wire is prepared by the preparation method according to any one of claims 1 to 9.