A surface mounted tantalum insulator shell and preparation method thereof

Abstract

The present invention relates to the technical field of insulators, and specifically provides a surface-mounted tantalum insulator shell and a preparation method thereof. The preparation method specifically comprises: obtaining a tantalum-nickel composite plate by explosively compounding a tantalum plate and a nickel plate, performing multiple rolling and vacuum annealing treatments; contacting the tantalum-nickel composite plate with the nickel layer and the tantalum layer with the punch, and performing stamping and punching a small hole at the bottom to obtain a shell; assembling the glass, the composite tantalum wire and the shell and then performing high-temperature sintering to obtain an insulator shell; inserting a nickel tube onto the composite tantalum wire below the bottom of the shell, and fixing the nickel tube and the composite tantalum wire by laser welding to obtain an insulator shell with a nickel tube; immersing the shell bottom of the insulator shell with a nickel tube into a lead-tin solder to obtain a surface-mounted tantalum insulator shell. The surface-mounted insulator shell can not only reduce the weight of the tantalum capacitor, save costs, improve production efficiency, and improve assembly reliability and long-term stability.

Description

Technical Field

[0001] The invention relates to the technical field of insulators, and specifically provides a surface mounted tantalum insulator shell and a preparation method thereof. Background Art

[0002] Insulators are key accessories for components installed between conductors at different potentials or between conductors and ground potential. They can protect the inside of components from damage, provide insulation for the two poles of components, and reduce or lower the voltage and mechanical stress on components. They are key components of components and can play an important role in the operation and use of components. Insulators should not fail due to various components caused by changes in environmental and electrical load conditions, otherwise the insulators will not play an important role and will damage the use and operation life of the entire equipment.

[0003] At present, the shell and cover of tantalum capacitors are made of pure tantalum. There are three difficulties in the current processing process that have not been effectively solved: (1) Tantalum is a powder metallurgy material. During the plastic deformation process such as stamping and stretching, its grain size will increase, resulting in a rapid increase in the surface hardness of the material and a much more serious hardening phenomenon than other materials, which reduces the product yield and makes it difficult to ensure the consistency of product size; (2) Tantalum has a face-centered hexagonal structure, and not only is it easy to lose particles during processing, but tantalum also has adhesion problems with the mold material, resulting in scratches, pits and other defects on the surface after stretching is completed; (3) The electrical connection method between tantalum and the outside is to weld nickel wire on tantalum. Due to the difference in expansion coefficient and melting point between nickel wire and tantalum, the nickel wire often detaches from the tantalum insulator, thus affecting the reliability of the entire machine. Tantalum material has poor wettability with lead-tin alloy, resulting in poor solderability of tantalum, which means that capacitors processed with tantalum cannot be directly soldered to circuit boards: (4) When using capacitors equipped with tantalum insulators, bolt installation is usually used to solve the problem of capacitor fixation and installation. This requires the addition of auxiliary components such as fixing brackets, bolts, nickel tubes, etc. This not only increases costs and reduces reliability, but is also very unfavorable for the space application of the entire machine, especially in the aerospace field. Summary of the invention

[0004] In view of the above problems existing in the prior art, the present invention uses tantalum-nickel explosion composite plate to be stamped into an insulator shell, and after high-temperature sintering the glass, composite tantalum wire and the shell, a nickel tube is sleeved under the bottom of the shell and welded and fixed, and a lead-tin welding layer is plated on the bottom of the shell and the nickel tube to obtain a surface-mounted insulator shell with stable performance and long-term reliability.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides a method for preparing a surface mounted tantalum insulator shell, and the preparation method specifically comprises:

[0006] The tantalum plate and the nickel plate are subjected to explosive cladding, multi-pass rolling and vacuum annealing to obtain a tantalum-nickel composite plate;

[0007] The tantalum-nickel composite plate is placed in a stamping mold, the nickel layer is in contact with the concave mold, and the tantalum layer is in contact with the convex mold, and stamping is performed and a small hole is punched at the bottom to obtain a shell;

[0008] The glass, the composite tantalum wire and the shell are assembled in a graphite mold and then sintered at high temperature to obtain an insulator shell;

[0009] The nickel tube is inserted onto the composite tantalum wire below the bottom of the shell, and the nickel tube and the composite tantalum wire are fixed by laser welding to obtain an insulator shell with a nickel tube;

[0010] The shell bottom of the insulator shell with the nickel tube is immersed in lead-tin solder to obtain a surface-mounted tantalum insulator shell in which the nickel tube and the shell bottom are uniformly plated with lead-tin solder.

[0011] Furthermore, the steps of obtaining a tantalum-nickel composite plate by explosively cladding a tantalum plate and a nickel plate, performing multiple rolling processes and vacuum annealing treatment specifically include:

[0012] The tantalum plate and the nickel plate are polished to remove oil stains, impurities and oxide layers on the surface to obtain treated tantalum plates and nickel plates;

[0013] Placing the treated nickel plate on a platform and evenly arranging a plurality of support frames, placing the treated tantalum plate on the support frames, and performing explosive composite with explosives to obtain a tantalum-nickel explosive composite plate;

[0014] The tantalum-nickel explosion composite plate is subjected to multiple rolling and vacuum annealing, and then to precision rolling and high vacuum annealing, and then naturally cooled to obtain the tantalum-nickel composite plate.

[0015] Furthermore, the explosives are expanded ammonium nitrate, No. 2 rock ammonium nitrate explosive, 94.5% porous ammonium nitrate and 5.5% diesel, powdered emulsion explosive and salt or TNT explosive, the amount of the explosives is 2-5g / cm3, and the detonation velocity is 2600-3200m / s.

[0016] Furthermore, the tantalum-nickel explosion composite plate is subjected to multiple rolling and vacuum annealing, and then to precision rolling and high vacuum annealing steps, which specifically include:

[0017] The deformation rate of each rolling process during the multi-pass rolling process is 35-65%;

[0018] The vacuum annealing temperature is 1000-1350°C, and the annealing time is 30-120min;

[0019] The deformation rate of the precision rolling is 10-20%; the temperature of the high vacuum annealing is 850-1150° C., and the time is 0.5-12 hours.

[0020] Furthermore, the composite tantalum wire is composited by an inner copper wire and an outer tantalum layer.

[0021] Furthermore, the process parameters of the high temperature sintering are:

[0022] The sintering temperature is 950-1050℃ and the holding time is 20-60min.

[0023] Based on the same inventive concept, an embodiment of the present invention further provides a surface-mounted tantalum insulator shell, wherein the surface-mounted tantalum insulator shell is prepared by the above-mentioned preparation method;

[0024] The surface mounted tantalum insulator shell comprises a shell, a nickel tube, a glass body and a composite tantalum wire;

[0025] The shell is an open cylinder, the shell is made of a tantalum-nickel composite plate, and a lead-tin solder layer is provided on the bottom surface of the shell;

[0026] One or more glass bodies are arranged on the bottom surface of the shell, and a composite tantalum wire is arranged through the glass body and perpendicular to the bottom surface;

[0027] A nickel tube is welded to the outside of the tantalum wire below the glass body, and a lead-tin solder layer is arranged outside the nickel tube.

[0028] Furthermore, the tantalum-nickel composite plate is chamfered at the shell opening.

[0029] Furthermore, the bottom surface of the glass body is flush with the bottom surface of the shell, forming a bulge inwardly.

[0030] Furthermore, the length of the composite tantalum wire is greater than the height of the shell.

[0031] Beneficial effects:

[0032] (1) The present invention uses a tantalum-nickel composite plate as the capacitor shell, and its bonding surface is flat and has no wave shape, stable performance, smooth surface, no scratches, pits and convex spots, and high yield rate. The tantalum layer is used as the inner surface of the shell, which can ensure the long-term stability of the liquid tantalum electrolytic capacitor. The nickel layer is used as the outer surface, which has good wettability with the lead-tin alloy, allowing the shell to be directly welded to the circuit board, which not only improves the long-term stability of the welding between the negative electrode and the tantalum, but also simplifies the structure of the insulator shell.

[0033] (2) The composite tantalum wire in the present invention is composed of an inner copper wire and an outer tantalum layer, which can increase the conductivity of the positive electrode, thereby avoiding the loss of electrical signals or the increase in heat of the tantalum wire after excessive current, which affects the sealing performance of the glass.

[0034] (3) In the present invention, the nickel tube and the composite tantalum wire are integrated by mechanical welding, which not only solves the problem that the nickel tube is easy to fall off in the traditional crimping method, but also avoids the influence of the contact resistance between the nickel tube and the tantalum in the traditional crimping method on the electrical signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A schematic diagram of a surface mounted tantalum insulator shell provided in an embodiment of the present invention;

[0036] Figure 2 For invention Figure 1 A partial enlarged view of area A.

[0037] [Description of Reference Numerals]

[0038] 1. Shell; 2. Composite tantalum wire; 3. Glass body; 4. Lead-tin solder layer; 5. Nickel tube; 6. Tantalum layer; 7. Nickel layer. DETAILED DESCRIPTION

[0039] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, they will be described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

[0040] Unless otherwise defined, all professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0041] Unless otherwise specified, various raw materials, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0042] The invention is further described below with reference to specific examples.

[0043] like Figure 1 , 2As shown, an embodiment of the present invention provides a schematic diagram and a partial enlarged diagram of a surface-mounted tantalum insulator shell, wherein the surface-mounted tantalum insulator shell comprises a shell (1), a nickel tube (5), a glass body (3), and a composite tantalum wire (2); the shell (1) is an open cylinder, and is obtained by pressing a double-layer composite metal material, wherein the double-layer composite metal material is a tantalum-nickel composite plate, and the tantalum-nickel composite plate is placed in a stamping die, wherein the nickel layer (7) of the composite plate contacts the concave die, and the tantalum layer (6) contacts the convex die, and a shell having an outer surface of a nickel layer (7) and an inner surface of a tantalum layer (6) is obtained by stamping; the shell replaces the traditional tantalum plate with the tantalum-nickel composite plate, which can not only reduce the weight of the tantalum capacitor and save costs, but also the tantalum layer on the inner surface can ensure the long-term working stability of the liquid tantalum electrolytic capacitor, and the nickel layer on the outer surface has good wettability with the tin-lead alloy, so that the shell can be directly welded to the circuit board, thereby improving the long-term stability of the enrichment and tantalum welding. The shell mouth is chamfered at an angle of 27°, which is convenient for laser welding and prevents the influence of the nickel layer on the welding, and at the same time enables a good welding surface to be formed after welding. The composite tantalum wire (2) is a composite tantalum wire with an outer layer of tantalum and an inner layer of copper, which is used to increase the conductivity of the positive electrode, thereby avoiding the loss of electrical signals, or the heat of the tantalum wire increases the sealing performance of the negative glass body after the current is too large. After the shell (1) is stamped and formed, a small hole is punched in the center of the bottom of the shell. The glass, the composite tantalum wire and the stamped shell are assembled in a graphite mold and then sintered at high temperature to form an insulator shell with insulation, sealing and acid resistance. The glass body (3) is arranged at the center of the bottom of the shell. The bottom surface of the glass body (3) is flush with the bottom surface of the shell, forming a bulge inwardly; the composite tantalum wire (2) penetrates the glass body (3) and is arranged along the axis of the cylinder. Its length is greater than the height of the cylindrical shell. The composite tantalum wire (2) below the bottom of the shell is provided with a nickel tube (5), and the composite tantalum wire (2) and the nickel tube (5) are fixed by laser welding. The shell bottom of the insulator shell obtained above is immersed in lead-tin solder, and the nickel tube and the bottom of the shell are evenly coated with a lead-tin solder layer (4) to obtain a surface-mounted insulator shell. It should be understood that one or more glass bodies can be arranged at any position on the bottom of the shell, and corresponding composite tantalum wires are arranged through the glass body and perpendicular to the bottom.

[0044] The following is a specific example to further illustrate the method for preparing the surface mount insulator housing.

[0045] Example 1

[0046] The 10 mm tantalum plate and the 12 mm nickel plate are polished to remove the oil, impurities and oxide layer on the surface to obtain the treated tantalum plate and the nickel plate; the treated nickel plate is placed on a platform, and a plurality of copper support frames are evenly arranged, the treated tantalum plate is placed on the support frame, and explosives are laid, the explosives are expanded ammonium nitrate, No. 2 rock ammonium nitrate explosive, 94.5% porous ammonium nitrate and 5.5% diesel, powdered emulsion explosive and salt or TNT explosive, and the laying amount of explosives is 3 g / cm 3 , detonate from the middle of the explosive, and perform explosion composite at a detonation speed of 2600-2800m / s to obtain a tantalum-nickel explosion composite plate; the tantalum-nickel explosion composite plate is rolled 3 times with a deformation rate of 30% each time, and vacuum annealed at 1000°C for 50min, and then precision rolled with a deformation rate of 15%, and high vacuum annealed at 950°C for 6h, and naturally cooled to obtain a tantalum-nickel composite plate.

[0047] The tantalum-nickel composite plate is placed in a stamping mold, the nickel layer is in contact with the concave die, and the tantalum layer is in contact with the convex die, and stamping is performed and a small hole is punched at the bottom to obtain a shell; glass, composite tantalum wire and the shell are placed in a graphite mold for assembly and then sintered at a high temperature of 1000° C. for 30 minutes to obtain an insulator shell; a nickel tube is sleeved onto the composite tantalum wire below the bottom of the shell, and the nickel tube and the composite tantalum wire are fixed by laser welding to obtain an insulator shell with a nickel tube; the shell bottom of the insulator shell with a nickel tube is immersed in lead-tin solder to obtain a surface-mounted tantalum insulator shell in which the nickel tube and the bottom of the shell are uniformly plated with lead-tin solder.

[0048] Example 2

[0049] The 15 mm tantalum plate and the 15 mm nickel plate are polished to remove the oil, impurities and oxide layer on the surface to obtain the treated tantalum plate and the nickel plate; the treated nickel plate is placed on the platform, and a plurality of copper support frames are evenly arranged, the treated tantalum plate is placed on the support frame, and explosives are laid, the explosives are expanded ammonium nitrate, No. 2 rock ammonium nitrate explosive, 94.5% porous ammonium nitrate and 5.5% diesel, powdered emulsion explosive and salt or TNT explosive, and the laying amount of explosives is 4 g / cm 3 , detonate from the middle of the explosive, and perform explosion composite at a detonation speed of 3000-3200m / s to obtain a tantalum-nickel explosion composite plate; the tantalum-nickel explosion composite plate is rolled 3 times with a deformation rate of 45% each time, and vacuum annealed at 1200°C for 100min, and then precision rolled with a deformation rate of 10%, and high vacuum annealed at 850°C for 10h, and naturally cooled to obtain a tantalum-nickel composite plate.

[0050] The tantalum-nickel composite plate is placed in a stamping mold, the nickel layer is in contact with the concave die, and the tantalum layer is in contact with the convex die, and stamping is performed to punch a small hole at the bottom to obtain a shell; the glass, the composite tantalum wire and the shell are placed in a graphite mold for assembly and then sintered at a high temperature of 950° C. for 55 minutes to obtain an insulator shell; a nickel tube is sleeved onto the composite tantalum wire below the bottom of the shell, and the nickel tube and the composite tantalum wire are fixed by a laser welding method to obtain an insulator shell with a nickel tube; the shell bottom of the insulator shell with a nickel tube is immersed in lead-tin solder to obtain a surface-mounted tantalum insulator shell in which the nickel tube and the bottom of the shell are uniformly plated with lead-tin solder.

[0051] Example 3

[0052] The 18 mm tantalum plate and the 20 mm nickel plate are polished to remove the oil, impurities and oxide layer on the surface to obtain the treated tantalum plate and the nickel plate; the treated nickel plate is placed on the platform, and a plurality of copper support frames are evenly arranged, the treated tantalum plate is placed on the support frame, and explosives are laid, the explosives are expanded ammonium nitrate, No. 2 rock ammonium nitrate explosive, 94.5% porous ammonium nitrate and 5.5% diesel, powdered emulsion explosive and salt or TNT explosive, and the laying amount of explosives is 5 g / cm 3 , detonate from the middle of the explosive, and perform explosion composite at a detonation speed of 2800-3000m / s to obtain a tantalum-nickel explosion composite plate; the tantalum-nickel explosion composite plate is rolled 4 times at a deformation rate of 55% each time, and vacuum annealed at 1350°C for 30min, and then precision rolled at a deformation rate of 10%, and high vacuum annealed at 1150°C for 1.0h, and the tantalum-nickel composite plate is obtained after natural cooling.

[0053] The tantalum-nickel composite plate is placed in a stamping mold, the nickel layer is in contact with the concave die, and the tantalum layer is in contact with the convex die, and stamping is performed to punch a small hole at the bottom to obtain a shell; the glass, the composite tantalum wire and the shell are placed in a graphite mold for assembly and then sintered at a high temperature of 1050° C. for 20 minutes to obtain an insulator shell; a nickel tube is sleeved onto the composite tantalum wire below the bottom of the shell, and the nickel tube and the composite tantalum wire are fixed by a laser welding method to obtain an insulator shell with a nickel tube; the shell bottom of the insulator shell with a nickel tube is immersed in lead-tin solder to obtain a surface-mounted tantalum insulator shell in which the nickel tube and the bottom of the shell are uniformly plated with lead-tin solder.

[0054] The embodiments described above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the technical scope of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing a surface mounted tantalum insulator shell, characterized in that: The preparation method specifically comprises: The tantalum plate and the nickel plate are subjected to explosive cladding, multi-pass rolling and vacuum annealing to obtain a tantalum-nickel composite plate; The tantalum-nickel composite plate is placed in a stamping mold, the nickel layer is in contact with the concave mold, and the tantalum layer is in contact with the convex mold, and stamping is performed and a small hole is punched at the bottom to obtain a shell; The glass, the composite tantalum wire and the shell are assembled in a graphite mold and then sintered at high temperature to obtain an insulator shell; The nickel tube is inserted onto the composite tantalum wire below the bottom of the shell, and the nickel tube and the composite tantalum wire are fixed by laser welding to obtain an insulator shell with a nickel tube; The bottom of the insulator shell with the nickel tube is immersed in lead-tin solder to obtain a surface-mounted tantalum insulator shell in which the nickel tube and the bottom of the shell are uniformly plated with lead-tin solder; The steps of obtaining a tantalum-nickel composite plate by explosively cladding a tantalum plate and a nickel plate, performing multiple rolling and vacuum annealing treatment specifically include: The tantalum plate and the nickel plate are polished to remove oil stains, impurities and oxide layers on the surface to obtain treated tantalum plates and nickel plates; Placing the treated nickel plate on a platform and evenly arranging a plurality of support frames, placing the treated tantalum plate on the support frames, and performing explosive composite with explosives to obtain a tantalum-nickel explosive composite plate; The tantalum-nickel explosion composite plate is subjected to multiple rolling and vacuum annealing, and then precision rolling and high vacuum annealing, and the tantalum-nickel composite plate is obtained after natural cooling; The tantalum-nickel explosion composite plate is subjected to multiple rolling and vacuum annealing, and then subjected to precision rolling and high vacuum annealing steps, which specifically include: The deformation rate of each rolling process during the multi-pass rolling process is 35-65%; The vacuum annealing temperature is 1000-1350°C, and the annealing time is 30-120min; The deformation rate of the precision rolling is 10-20%; the temperature of the high vacuum annealing is 850-1150° C., and the time is 0.5-12 hours.

2. The method for preparing a surface mounted tantalum insulator shell according to claim 1, characterized in that: The explosives are expanded ammonium nitrate, No. 2 rock ammonium nitrate explosive, 94.5% porous ammonium nitrate and 5.5% diesel, powdered emulsion explosive and salt or TNT explosive, and the amount of the explosives is 2-5g / cm 3 , the explosion speed is 2600-3200m / s.

3. The method for preparing a surface mounted tantalum insulator shell according to claim 1, characterized in that: The composite tantalum wire is composited by an inner copper wire and an outer tantalum layer.

4. The method for preparing a surface mounted tantalum insulator shell according to claim 1, characterized in that: The process parameters of the high temperature sintering are: The sintering temperature is 950-1050℃ and the holding time is 20-60min.

5. A surface mounted tantalum insulator shell, characterized in that: The surface mounted tantalum insulator shell is prepared by the preparation method according to any one of claims 1 to 4; The surface mounted tantalum insulator shell comprises a shell, a nickel tube, a glass body and a composite tantalum wire; The shell is an open cylinder, the shell is made of a tantalum-nickel composite plate, and a lead-tin solder layer is provided on the bottom surface of the shell; One or more glass bodies are arranged on the bottom surface of the shell, and a composite tantalum wire is arranged through the glass body and perpendicular to the bottom surface; A nickel tube is welded to the outside of the tantalum wire below the glass body, and a lead-tin solder layer is arranged outside the nickel tube.

6. The surface mounted tantalum insulator shell according to claim 5, characterized in that: The tantalum-nickel composite plate is chamfered at the shell opening.

7. The surface mounted tantalum insulator shell according to claim 5, characterized in that: The bottom surface of the glass body is flush with the bottom surface of the shell, forming a bulge inwardly.

8. The surface mounted tantalum insulator shell according to claim 5, characterized in that: The length of the composite tantalum wire is greater than the height of the shell.

Images