A kind of solid film capacitor with self-healing function and preparation method thereof

Abstract

The invention relates to a solid-state thin film capacitor having a self-repair function and a fabrication method of the solid-state thin film capacitor. The capacitor comprises a substrate (1), a lower-part electrode (2), an active glass doped aluminum oxide thin film (3) and an upper-part electrode (4), wherein the lower-part electrode (2) is coated on a surface of the substrate (1), and the active glass doped aluminum oxide thin film (3) is arranged between the upper-part electrode (4), and the lower-part electrode (2). Compared with the prior art, the solid-state thin film capacitor is simple in structure and fabrication process, good in dielectric performance and high in energy storage density, and self-repair can be achieved; and moreover, the solid-state thin film is used as an electrical medium, no electrolyte exists in the solid-state thin film capacitor, and thus, the solid-state thin film capacitor is safe and reliable to use.

Description

technical field [0001] The invention belongs to the technical field of capacitor preparation, and relates to a solid film capacitor with self-repair function and a preparation method thereof. Background technique [0002] During the manufacture and use of capacitors, various defects will inevitably appear in the dielectric film. One of the key technologies to realize the work of the dielectric film under a strong field is the defect self-healing or self-repairing of the dielectric. Traditional capacitors with self-healing functions include aluminum electrolytic capacitors, tantalum electrolytic capacitors, and metallized film capacitors. [0003] The aluminum electrolytic capacitor uses the electrolyte as the cathode. Under the action of the applied voltage, the O in the non-solid electrolyte 2- Al that is rapidly transported to the defect and ionized from the aluminum substrate 3+ Combined, the oxide film is re-formed at the damaged oxide film to restore the normal workin...

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Problems solved by technology

However, it is precisely because of the existence of these electrolytes that the safety and reliability of the capacitor are greatly affected, such as the leakage of the electrolyte; after the electrolytic capacitor has been working for a long time, the capacitor explosion caused by the electrolyte; in the electrolytic capacitor, the electrolytic The liquid and its protection device occupy a lot of space, which greatly limits the improvement of its energy storage density and other issues; as the electrolyte in the aluminum electrolytic capacitor dries up, the negative electrode area of ​​the aluminum electrolytic capacitor will be greatly reduced, and the distance between the positive and negative electrodes It also increases, and this increase is no longer alumina with a high dielectric constant, so the capacitance of the aluminum electrolytic capacitor will be greatly reduced and fail, causing the problem of short life of the aluminum electrolytic capacitor

Tantalum solid capacitors use solid MnO 2 As an electrolyte, its safety and stability are better than electrolytic capacitors, but its price is expensive, its capacitance is small, its application range is limited, and in tantalum capacitors MnO 2 The occupied volume is relatively large, which will limit the improvement of its own energy storage density

Metallized film capacitors also have their inherent defects: one is that metallized capacitors are prone to capacity loss in long-term working conditions and will cause capacity reduction after self-healing; another disadvantage is that they have poor ability to withstand large currents. The chemical film layer is much thinner than the metal foil, and the ability to carry large currents is weak

Unlike aluminum electrolytic capacitors, there is no liquid electrolyte in this capacitor, but an active alumina solid film with electrolyte function is used as the oxygen provider in anodic oxidation, which avoids the problems caused by the presence of electrolyte, but the capacitor needs A barrier-type oxide film is regenerated between the aluminum oxide film and the electrode for repair, thus limiting the need for the electrode to be a valve metal with anodic oxidation function, which greatly limits its application conditions

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