Preparation Technology Explore For Dielectric Oxide Film Of High Voltage Hybrid Tantalum Capacitors

As a newcapacitor, hybrid tantalum capacitor has the energy density like an electrochemical capacitor and the AC character as the electrolytic capacitor. Thus hybrid tantalum capacitors has caused concern of field with application of tantalum or aluminum electrolytic capacitors.The main purpose of this subject is to searching the preparation process for dielectric oxide film of high voltage hybrid capacitors(representative value of 125V-1100μF).Firstly, based on traditional non-solid electrolytic tantalum capacitor production line and process, we have analyzed several key process, including anode design, pressing, and sintering, and key materials,including tantalum powder, tantalum wire and binder according to the construction and performance of tantalum capacitors. Uniform, compact and high mechanical stress resistance sintered pellets have been found through test, comparison and research.Secondly, with the instruction of dielectric oxide film growth mechanism, crystallization mechanism, self healing mechanism, we have deeply analyzed and researched the process parameters(including formation temperature, formation current density, constant voltage time, formation solution formula) affected dielectric oxide film, formation process parameter has been confirmed based on multi-factor and multi-level orthogonal test.Finally, representative hybrid tantalum capacitors with values 125V-1100μF was trail produced with relative process parameters, the products’ character at room temperature and character at low and high temperature were measured following assembly, soldering, acid filled, burn in and aging. Then 2000 hours life test were performed at 85℃ and 125℃. The measured value at room temperature and low and high temperature have significant improvement. The electrical parameter drift has been improved efficiently. The expected target has been achieved.Through the subject research, the preparation process for dielectric oxide film of high voltage hybrid tantalum capacitor has been grasped primarily. Based on traditional process,new material, process and technology of organics as binder, pressed cover sintered pellets and twice formation have been proposed for the first time. This provides ideas and instruction for manufacturing high reliable, high stable and long life high voltage series hybrid tantalum capacitors and improving input-output ration.