Preparation method of chip polymer laminated aluminum electrolytic capacitor

Abstract

The invention relates to the technical field of preparation of electrolytic capacitors, in particular to a preparation method of a chip polymer laminated aluminum electrolytic capacitor, which comprises the following steps of: S1, removing an oxidation film on the surface of a core anode to obtain a first core; s2, the anode surface and the cathode surface of the first core are bonded through ACF adhesive tape, and a second core is obtained; s3, a plurality of second cores are stacked and then subjected to hot-pressing curing treatment, and a capacitor core package is obtained; s4, packaging, aging and forming treatment are conducted on the capacitor core package, and the solid aluminum electrolytic capacitor is obtained.According to the solid aluminum electrolytic capacitor, the anodic oxide film removing technology and the ACF adhesive tape bonding technology are adopted, and the hot pressing mode is combined; the problems of insufficient welding strength, welding slag phenomenon, silver paste bonding operation, uneven stress caused by a fan-shaped structure and the like in the prior art can be effectively solved, and the electrical performance and the reliability of the product are improved. And meanwhile, by using the ACF adhesive tape, the operation process is more stable and controllable, and industrial production can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolytic capacitor preparation, in particular to a method for preparing a chip-type polymer laminated aluminum electrolytic capacitor. Background Art

[0002] Aluminum electrolytic capacitors are capacitors constructed by using an anodic oxidation method to form a thin layer of aluminum oxide as the dielectric layer on the surface of valve metal aluminum, with an electrolyte as the cathode. Aluminum electrolytic capacitors are divided into liquid aluminum electrolytic capacitors and solid aluminum electrolytic capacitors according to the state of the electrolyte.

[0003] The conventional process for polymer laminated aluminum electrolytic capacitors uses resistance welding to weld the anodes, then hot-pressing and curing the silver paste to connect the cathodes, forming a parallel structure. However, this method presents the following problems: 1. Welding high-voltage aluminum foil can result in inconsistent weld strength, leading to anode detachment and low weld yields for more than five layers on a single side. Industrialized stable production is difficult, requiring laser welding or a combination of resistance welding and gasketing, increasing equipment and material costs. 2. Resistance welding machines produce significant slag during multi-layer welding, affecting airtightness after packaging. 3. The silver paste used is a slurry, which can lead to problems such as stringing, overflow, and difficulty in dimensional control during the manufacturing process. To address these issues, the present invention has developed a method for preparing chip-type polymer laminated aluminum electrolytic capacitors. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing a chip-type polymer laminated aluminum electrolytic capacitor to solve the problems of insufficient welding strength, welding slag, and silver paste bonding in the existing method.

[0005] To achieve the above objectives, the technical solution provided by the present invention is: A method for preparing a chip-type polymer laminated aluminum electrolytic capacitor comprises the following steps: S1, removing the oxide film on the surface of the core anode to obtain a first core; S2, using ACF tape to bond the anode surface and cathode surface of the first core respectively to obtain a second core; S3, stacking a plurality of second cores and performing a heat pressing and curing process to obtain a capacitor core package; S4. The capacitor core package is packaged, aged and formed to obtain a solid aluminum electrolytic capacitor.

[0006] Preferably, in step S1, the oxide film on the surface of the core anode is removed by laser removal or mechanical grinding.

[0007] Preferably, the specific process of hot pressing curing in step S3 is: S31, stacking a plurality of second cores in sequence and placing them into a hot pressing mold; S32, vacuuming the hot pressing mold to remove air from the hot pressing mold; S33, placing the hot pressing mold into an autoclave or hot press, applying high temperature and high pressure to solidify the material; S34. After curing is completed, maintain the pressure and gradually cool to room temperature, and finally take out the cured product.

[0008] Preferably, the temperature of the hot pressing curing is 60° C. to 260° C., and the time of the hot pressing curing is 3-30 seconds.

[0009] Preferably, in step S31 , after a plurality of second cores are stacked in sequence, the anode lead frame and the cathode lead frame are respectively inserted into the anode region and the cathode region of the second core, and then placed into a hot pressing mold.

[0010] Preferably, in step S31 , ACF tape or conductive polymer is evenly placed in the hot pressing mold corresponding to the cathode area of ​​the second core.

[0011] Preferably, in step S2, before bonding, the ACF tape is cut into a shape that matches the core anode and the core cathode.

[0012] Compared with the prior art, the present invention has the following beneficial effects: By combining an anodic oxide film removal process with ACF tape bonding technology, coupled with hot pressing, this invention effectively addresses existing issues such as insufficient welding strength, slag, silver paste bonding problems, and uneven force distribution caused by the fan-shaped structure, thereby improving the product's electrical performance and reliability. Furthermore, the use of ACF tape makes the process more stable and controllable, facilitating industrial production. DETAILED DESCRIPTION

[0013] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0014] One embodiment of the present invention is: A method for preparing a chip-type polymer laminated aluminum electrolytic capacitor comprises the following steps: S1. Remove the oxide film on the anode surface of the core to obtain the first core. Remove the oxide film on the anode surface so that the ACF tape can directly contact the aluminum foil surface to form a strong electrical connection and avoid poor connection caused by uneven thickness of the oxide film. S2, using ACF tape to bond the anode surface and cathode surface of the first core respectively to obtain a second core; S3. Stacking several second cores and performing a hot pressing and curing process to obtain a capacitor core pack. During the hot pressing process, the conductive particles in the ACF tape deform and fuse under the action of pressure and temperature, forming a stable electrical connection and enhancing the bonding strength between the ACF tape and the aluminum foil; S4. The capacitor core package is packaged, aged and formed to obtain a solid aluminum electrolytic capacitor.

[0015] Specifically, in step S1, the oxide film on the surface of the core anode is removed by laser removal or mechanical grinding.

[0016] Specifically, the specific process of hot pressing curing in step S3 is: S31, stacking a plurality of second cores in sequence and placing them into a hot pressing mold; S32, vacuuming the hot pressing mold to remove air inside the hot pressing mold to ensure that there are no bubbles in the material during the curing process; S33, placing the hot pressing mold into an autoclave or hot press, applying high temperature and high pressure to solidify the material; S34. After curing is completed, maintain the pressure and gradually cool to room temperature, and finally take out the cured product.

[0017] Specifically, the temperature of the hot pressing curing is 60° C. to 260° C., and the time of the hot pressing curing is 3 to 30 seconds.

[0018] Specifically, in step S31 , after a plurality of second cores are stacked in sequence, the anode lead frame and the cathode lead frame are respectively inserted into the anode region and the cathode region of the second core, and then placed into a hot pressing mold.

[0019] Specifically, in step S31 , ACF tape or conductive polymer is evenly placed in the hot pressing mold corresponding to the cathode area of ​​the second core.

[0020] Specifically, in step S2, before bonding, the ACF tape is cut into a shape that matches the core anode and the core cathode.

[0021] From the above description, it can be seen that by precisely controlling the shape, size (length, width, and height) of the ACF tape and the thickness of the anode and cathode ACF tapes, the force distribution between the anode and cathode can be better adjusted, thereby reducing the impact of the fan-out effect on capacitor performance.

[0022] Example 1: A method for preparing a chip-type polymer laminated aluminum electrolytic capacitor comprises the following steps: S1. Using laser removal to remove the oxide film on the anode surface of the core to obtain the first core. Removing the oxide film on the anode surface allows the ACF tape to directly contact the aluminum foil surface to form a strong electrical connection, avoiding poor connection problems caused by uneven thickness of the oxide film. S2. Adhere the anode surface and cathode surface of the first core respectively with ACF tape to obtain a second core. Before the ACF tape is adhered, cut the ACF tape into shapes that match the anode region and cathode region of the first core. S3. Stacking several second cores and performing a hot pressing and curing process to obtain a capacitor core pack. During the hot pressing process, the conductive particles in the ACF tape deform and fuse under the action of pressure and temperature, forming a stable electrical connection and enhancing the bonding strength between the ACF tape and the aluminum foil; Thermal curing is specifically as follows: S31, stacking a plurality of second cores in sequence, inserting lead frames into corresponding anode and cathode regions, and placing them into a hot pressing mold; S32, vacuuming the hot pressing mold to remove air inside the hot pressing mold to ensure that there are no bubbles in the material during the curing process; S33, placing the hot pressing mold into an autoclave or hot press, applying high temperature and high pressure to solidify the material, wherein the hot pressing curing temperature is 120° C. and the hot pressing curing time is 15 seconds; S34. After curing is completed, maintain the pressure and gradually cool to room temperature, and finally take out the cured product S4. The capacitor core package is packaged, aged and formed to obtain a solid aluminum electrolytic capacitor.

[0023] Compared with the existing preparation method, the present invention has the following significant advantages: Improved welding strength and stability: By completely removing the oxide film on the anode surface and using ACF tape for bonding, the welding strength and stability are significantly improved, and the anode shedding phenomenon is avoided.

[0024] Eliminate welding slag: The use of ACF tape replaces the traditional resistance welding process, thereby eliminating the welding slag phenomenon and improving the airtightness and product reliability after packaging.

[0025] Optimize the operation process: The solid form of ACF tape makes the operation process more stable and controllable, avoiding various problems in the bonding silver paste operation, and improving production efficiency and product quality.

[0026] Reduced fan-out effect: By precisely controlling the shape and size of the ACF tape and the thickness of the anode and cathode tapes, the impact of the fan-out effect on capacitor performance is effectively reduced, improving the product's electrical performance.

[0027] Reduce production costs: The use of ACF tape makes the operation process more automated and controllable, which is conducive to industrialized production, thereby reducing production costs and improving market competitiveness.

[0028] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a chip-type polymer laminated aluminum electrolytic capacitor, characterized by: The following steps are involved: S1, removing the oxide film on the surface of the core anode to obtain a first core; S2, using ACF tape to bond the anode surface and cathode surface of the first core respectively to obtain a second core; S3, stacking a plurality of second cores and performing a heat pressing and curing process to obtain a capacitor core package; S4. The capacitor core package is packaged, aged and formed to obtain a solid aluminum electrolytic capacitor.

2. The method for preparing a chip-type polymer laminated aluminum electrolytic capacitor according to claim 1, characterized in that: In step S1, the oxide film on the surface of the core anode is removed by laser removal or mechanical grinding.

3. The method for preparing a chip-type polymer laminated aluminum electrolytic capacitor according to claim 1, wherein: The specific process of hot pressing curing in step S3 is as follows: S31, stacking a plurality of second cores in sequence and placing them into a hot pressing mold; S32, vacuuming the hot pressing mold to remove air from the hot pressing mold; S33, placing the hot pressing mold into an autoclave or hot press, applying high temperature and high pressure to solidify the material; S34. After curing is completed, maintain the pressure and gradually cool to room temperature, and finally take out the cured product.

4. The method for preparing a chip-type polymer laminated aluminum electrolytic capacitor according to claim 3, characterized in that: The temperature of the hot pressing curing is 60° C. to 260° C., and the time of the hot pressing curing is 3 to 30 seconds.

5. The method for preparing a chip-type polymer laminated aluminum electrolytic capacitor according to claim 3, characterized in that: In step S31 , after a plurality of second cores are stacked in sequence, an anode lead frame and a cathode lead frame are respectively inserted into the anode region and cathode region of the second core, and then placed into a hot pressing mold.

6. The method for preparing a chip-type polymer laminated aluminum electrolytic capacitor according to claim 3, wherein: In the step S31 , ACF tape or conductive polymer is evenly placed in the hot pressing mold corresponding to the cathode area of ​​the second core.

7. The method for preparing a chip-type polymer laminated aluminum electrolytic capacitor according to claim 1, characterized in that: In the step S2, before bonding, the ACF tape is cut into a shape that matches the core anode and the core cathode.