Preparation method of high-reliability small-size high-energy hybrid tantalum capacitor

Abstract

According to the preparation method of the high-reliability small-size high-energy hybrid tantalum capacitor provided by the invention, tantalum powder is subjected to compression molding, sintering and energizing to obtain a tantalum core, and the tantalum core is packaged to obtain the tantalum capacitor. The method of changing the forming mode of the tantalum core, reducing the size of the tantalum core and improving the sintering temperature is adopted, so that the tantalum wire does not have brittle failure under the condition that the strength of the tantalum core is ensured, and through the design of the ultra-small-size anode tantalum core and the ultra-thin tantalum shell, the size of the anode tantalum core is increased, and the appearance size of the capacitor is reduced; therefore, sufficient capacitance of the tantalum core with small enough size is ensured, and the small-size high-energy hybrid tantalum capacitor with high reliability is obtained.

Description

Technical Field

[0001] The invention relates to a method for preparing a high-reliability, small-size, high-energy hybrid tantalum capacitor. Background Art

[0002] As the working environment of high-end equipment continues to change, high-energy hybrid tantalum capacitors are required to be miniaturized and lightweight while ensuring reliability. Therefore, in order to adapt to market changes, high-energy hybrid tantalum capacitors continue to develop and innovate with a variety of lead-out methods, multiple sizes and installation methods. Due to the limited installation space in high-precision equipment, conventional cylindrical high-energy hybrid tantalum capacitors are still relatively large for high-precision equipment. Therefore, while ensuring reliability, reducing the package size of high-energy hybrid tantalum capacitors is very important for the miniaturization of aviation flight equipment. For example, CN117995561B discloses an organic chip solid tantalum electrolytic capacitor and its preparation method, tantalum powder is pressed into tantalum blocks, sintered under vacuum conditions; the sintered blocks are impregnated with an energy forming liquid, washed in a high-temperature steam environment, and then vacuum annealed, and then impregnated with the original energy forming liquid and a DC voltage is applied to enable the tantalum core; but the voltage segment boosting enabling is not used, resulting in a relatively low efficiency of dielectric layer formation during the enabling process, thereby increasing the production cycle. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for preparing a high-reliability, small-size, high-energy hybrid tantalum capacitor.

[0004] The present invention is achieved through the following technical solutions.

[0005] The present invention provides a method for preparing a high-reliability, small-size, high-energy hybrid tantalum capacitor, the steps of which are:

[0006] 1) Put 1350±10 mg of tantalum powder with a specific volume of 21000 μF·V / g into a program mold for pressing and slowly demolding to obtain a tantalum block;

[0007] 2) Sinter at 1395±10℃, keep at temperature for (20±5)min, cool to 30℃ and take out of the furnace;

[0008] 3) Using phosphoric acid-ethylene glycol solution as the energy-enabling solution, placing the sintered tantalum block into the energy-enabling solution for voltage-stepping energy-enabling in different voltage segments;

[0009] 4) Assembling the tantalum core with Ta2O5 dielectric oxide film in the housing, and using laser welding to weld the cover plate and leads for packaging to obtain a tantalum capacitor;

[0010] 5) Perform aging on tantalum capacitors.

[0011] The forming mold is a cylindrical tube with a diameter of φ10.5, and the inner wall of the forming mold is coated with lubricating oil.

[0012] In step 1), the tantalum powder is shaken before pressing to make it evenly distributed in the molding die.

[0013] The specific capacitance of the tantalum block and tantalum powder after sintering in step 2) is 21000 μF·V / g.

[0014] The segment voltages in step 3) are:

[0015] The first voltage range is 40-80V, and the boost current density is 0.006mA / g;

[0016] The second stage is 80-120V, and the boost current density is 0.005mA / g;

[0017] When the voltage is boosted to 120V, the constant voltage is 4.0h±5min at 120V.

[0018] The shell is an ultra-thin tantalum shell of Φ12×9mm.

[0019] The cover plate is an insulator cover plate with a size of Φ11.4×9.7 mm.

[0020] The beneficial effects of the present invention are as follows: by changing the molding method of the tantalum core, reducing the size of the tantalum core, and increasing the sintering temperature, the strength of the tantalum core is guaranteed and the tantalum wire does not break brittlely; by designing an ultra-small anode tantalum core and an ultra-thin tantalum shell, the volume of the anode tantalum core is increased and the outer dimensions of the capacitor are reduced, thereby ensuring that the capacitance of the tantalum core of a sufficiently small size is sufficient, and a small-sized high-energy hybrid tantalum capacitor with high reliability is obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 Schematic diagram of the lead structure of the present invention

[0023] In the figure: 1-housing, 2-cover plate, 3-positive electrode lead, 4-negative electrode lead. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0025] 1) Weigh (1350±10) mg of tantalum powder with a specific volume of 21000 μF·V / g using an electronic analytical balance, and use a φ10.5 molding mold with a lubricant to mold. Shake the tantalum powder evenly before molding to ensure uniform compacting density, and slowly demold to obtain an anode tantalum block with a certain strength; use Ф0.5 mm straight tantalum wire and a chamfered mold for manual molding to avoid exposure of the tantalum wire and damage to the root of the tantalum core; use a high-temperature sintering method of (1395±10)℃ / (20±5)min for sintering to ensure the strength of the tantalum core and that the tantalum wire does not become brittle.

[0026] 2) Sintering is performed at a high temperature of (1395±10)°C, and maintained for (20±5) minutes after reaching the temperature. The furnace is then removed after cooling to 30°C to ensure that the specific capacitance of the tantalum core and tantalum powder after sintering is around 21000μF·V / g.

[0027] 3) Conventional phosphoric acid-ethylene glycol solution was used for voltage step-up formation, with a boost current density of 0.008 mA / g at (0-40) V, a boost current density of 0.006 mA / g at (40-80) V, and a boost current density of 0.005 mA / g at (80-120) V. When the voltage reached 120 V, the voltage was kept constant for 4.0 h ± 5 min, and a tantalum core with a good Ta2O5 dielectric oxide film was prepared.

[0028] 4) The tantalum core with the Ta2O5 dielectric oxide film is assembled according to conventional methods and laser welded using conventional packaging methods.

[0029] 5) Use conventional open aging and sealed aging procedures for aging.

[0030] By reducing the thickness of the tantalum shell from 0.5mm to an ultra-thin design of 0.35mm, the installation area occupied by this specification product on the printed circuit board is reduced from 200mm 2 Reduced to 113mm 2 , reducing the installation area by 43.5% compared to the existing level;

[0031] The appearance and lead-out method of the high-reliability, small-size, high-energy hybrid tantalum capacitor prepared in the above implementation are as follows: Figure 1 and 2 The detailed design comparison data of the capacitor is shown in Table 1. The capacitor designed by this method not only realizes small-size packaging production, but also has excellent electrical performance parameters.

[0032] The capacitor prepared by the method of the present invention not only has the advantage of small shell size, but also has high reliability and capacitance accuracy, small ESR and leakage current. The electrical performance data are shown in Table 1.

[0033] Table 1: Comparison of capacitor parameters

[0034]

[0035] As can be seen from Table 1, the method of the present invention not only successfully manufactures high-reliability, small-sized, high-energy hybrid tantalum capacitors, but also the capacitors manufactured by the method have high capacitance accuracy, low ESR, and small leakage current.

Claims

1. A method for preparing a high-reliability, small-size, high-energy hybrid tantalum capacitor, comprising the following steps: 1) Put 1350±10 mg of tantalum powder with a specific volume of 21000 μF·V / g into a program mold for pressing and slowly demolding to obtain a tantalum block; 2) Sinter at 1395±10℃, keep at temperature for (20±5)min, cool to 30℃ and take out of the furnace; 3) Using phosphoric acid-ethylene glycol solution as the energy-enabling solution, placing the sintered tantalum block into the energy-enabling solution for voltage-stepping energy-enabling in different voltage segments; 4) Assembling the tantalum core with Ta2O5 dielectric oxide film in the housing, and using laser welding to weld the cover plate and leads for packaging to obtain a tantalum capacitor; 5) Perform aging on tantalum capacitors.

2. The method for preparing a high-reliability, small-size, high-energy hybrid tantalum capacitor according to claim 1, characterized in that: The forming mold is a cylindrical tube with a diameter of φ10.5, and the inner wall of the forming mold is coated with lubricating oil.

3. The method for preparing a high-reliability, small-size, high-energy hybrid tantalum capacitor according to claim 1, characterized in that: In the step 1), the tantalum powder is evenly distributed in the molding die by shaking before pressing.

4. The method for preparing a high-reliability, small-size, high-energy hybrid tantalum capacitor according to claim 1, characterized in that: The specific capacitance of the tantalum block and tantalum powder after sintering in the step 2) is 21000 μF·V / g.

5. The method for preparing a high-reliability, small-size, high-energy hybrid tantalum capacitor according to claim 1, characterized in that: The segment voltages in step 3) are respectively: The first voltage range is 40-80V, and the boost current density is 0.006mA / g; The second stage is 80-120V, and the boost current density is 0.005mA / g; When the voltage is boosted to 120V, the constant voltage is 4.0h±5min at 120V.

6. The method for preparing a high-reliability, small-size, high-energy hybrid tantalum capacitor according to claim 1, characterized in that: The shell is an ultra-thin tantalum shell of Φ12×9mm.

7. The method for preparing a high-reliability, small-size, high-energy hybrid tantalum capacitor according to claim 1, characterized in that: The cover plate is an insulator cover plate with a size of Φ11.4×9.7 mm.

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