Method for producing solid sheet type electrolytic capacitor

Abstract

A manufacturing method for a solid plate electrolytic capacitor is to weld a strip Al foil to a stainless steel technical bar, the Al foil is coated with silicon resin or F resin to be divided into cathode and anode. The cathode part is immersed into a solution containing oxalamine and ammonium biphosphate plus 6-35v voltage, then again immersed in KMno4 solution to be dipped in a solution with Py and sulfosalt to form a pre-conductive layer on its surface as the anode, a stainless steel as the cathode to carry out constant current electrolyte in a mixed solution with Py and sulfosalt. The Al foil cathode is immersed in a solution containing oxalamine, ammonium biphosphate and sulfosalt plus 5-25v voltage to be coated with graphite and Ag to get single chip cores to be laminated, the anode is welded at that of an alloy lead frame, the cathode to the cathode to form a capacitor core to be molded and packaged with epoxy resin.

Description

technical field [0001] The invention relates to a method for manufacturing an electrolytic capacitor, in particular to a method for manufacturing a solid chip electrolytic capacitor with a conductive polymer solid electrolyte with high conductivity. Background technique [0002] In recent years, with the development of high-frequency computer and communication technology, newer and higher requirements have been put forward for the performance of electronic components. Specifically for capacitors, it is required that capacitors have small volume and large capacity, low equivalent series resistance (ESR), small loss tangent (tgδ), high upper limit operating frequency (about 1MHz), and wide operating temperature range (-55 ℃-+125℃), with chip structure and other performance characteristics; in addition, due to the rapid development of surface mount technology (SMT), the demand for chip electrolytic capacitors is increasing. [0003] Because the traditional aluminum electrolyti...

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Problems solved by technology

[0003] Because the traditional aluminum electrolytic capacitor uses liquid electrolyte as the cathode, the conductivity of the liquid electrolyte is generally less than 10mS / cm. The equivalent series resistance formed by the electrolyte cathode is the main part of the equivalent series resistance of the traditional aluminum electrolytic capacitor. Therefore, the traditional aluminum The loss tangent of electrolytic capacitors is difficult to be less than 5%

In addition, because the properties of the liquid change greatly with temperature, there are obvious deficiencies in the temperature characteristics, frequency characteristics, and reliability of traditional aluminum electrolytic capacitors. The sealing of the liquid electrolyte is also the biggest obstacle to the miniaturization and chip type of capacitors.

While traditional tantalum electrolytic capacitors use MnO 2 The solid electrolyte is used as the cathode, which greatly improves the temperature characteristics of the liquid aluminum electrolytic capacitor, and also solves the problem of miniaturization and chip type, but due to the MnO 2 The conductivity of the capacitor is generally less than 1S / cm. Compared with the liquid aluminum electrolytic capacitor, although the frequency characteristic is greatly improved, it is still insufficient.

Furthermore, MnO 2 Solid electrolytes are generally prepared by high-temperature thermal decomposition, and the dielectric insulation properties are likely to deteriorate during the preparation process; in addition, when the "self-healing" process of tantalum electrolytic capacitors occurs, due to local overheating and high temperature, MnO 2 Thermal decomposition occurs to release oxygen atoms or oxygen, which sometimes causes the burning of the epoxy encapsulant of tantalum capacitors, resulting in the destruction of the circuit board or even the entire electronic device