technology for recovering silver and palladium from multilayer ceramic capacitors (MLCC) scraps was studied. 91% silver and 98% palladium are respectively leached from scraps (200 mesh) under the conditions of 4 mol/L...technology for recovering silver and palladium from multilayer ceramic capacitors (MLCC) scraps was studied. 91% silver and 98% palladium are respectively leached from scraps (200 mesh) under the conditions of 4 mol/L HNO_3, 80℃, 2 h (s/l=1∶3). Silver can be precipitated with hydrochloric acid from leaching solutions. Purity of coarse silver bullion obtained from melting silver chloride is 98%. Silver recovery is 88%. Palladium can be reduced and precipitated respectively from silver raffinate and leaching residue scrub solutions by iron powders and butyl xanthate. Purity of palladium is 99.95% by traditional refining method. Palladium recovery is 95%.展开更多
The glass-ceramic dielectrics and internal electrode structures are investigated for improving the general energy storage density of capacitors. Calculation indicates that glass-ceramics acquired from glass matrix ann...The glass-ceramic dielectrics and internal electrode structures are investigated for improving the general energy storage density of capacitors. Calculation indicates that glass-ceramics acquired from glass matrix annealing at 850℃ for 3 hours can be approximately up to 17 J/cm3 in energy storage density. They are appropriately chosen as the dielectrics for preparing high energy storage density capacitors (HESDCs). A series multilayer structure of internal electrode is developed for the HESDCs, in which each layer is a combination of gold film and silver paste. This electrode structure promises the capacitor immune from the residual porosity defects inevitably brought by electrode paste sintering process, and specifically improves the electrical breakdown strength of the capacitor. Based on this new electrode structure, the energy storage densities of capacitors are increased by more than one order of magnitude compared with those traditional ones with only single layer of internal electrode. Thus, HESDCs based on the optimized glass-ceramic dielectrics can potentially achieve 7.5 J/cm3 in energy storage density, even taking into consideration the enlargement of total capacitor volumes while encapsulating practicable capacitors from dielectrics media.展开更多
多层陶瓷电容器(MLCCs)体现了电子元器件小型化、复合化、低成本、高可靠性的发展趋势。BME(BaseMetal Electrode)技术的发展促进了 Ni 内电极 MLCCs 的生产和应用。为了适应贱金属 Ni 内电极 MLCCs 还原气氛烧结需要,对介质瓷料提出了...多层陶瓷电容器(MLCCs)体现了电子元器件小型化、复合化、低成本、高可靠性的发展趋势。BME(BaseMetal Electrode)技术的发展促进了 Ni 内电极 MLCCs 的生产和应用。为了适应贱金属 Ni 内电极 MLCCs 还原气氛烧结需要,对介质瓷料提出了抗还原性要求,使其具有高的绝缘电阻率和长的工作寿命。综述了 BaTiO_3 基介质瓷料的抗还原性措施,涉及电子缺陷浓度的降低以及氧空位缺陷迁移的抑制,并利用缺陷化学阐述了其 A 位施主和 B 位受主掺杂的改性机理。展开更多
近年来,随着技术逐渐成熟,在欧美等国,BME MLCC已经逐渐进入宇航应用领域。相对传统的PME MLCC,BM E M LCC具有缓慢老化失效模式、介质减薄等特性,也存在可靠性风险。从"初步评估、详细评估、鉴定检验"宇航鉴定思路出发,结合...近年来,随着技术逐渐成熟,在欧美等国,BME MLCC已经逐渐进入宇航应用领域。相对传统的PME MLCC,BM E M LCC具有缓慢老化失效模式、介质减薄等特性,也存在可靠性风险。从"初步评估、详细评估、鉴定检验"宇航鉴定思路出发,结合电容器失效模式和失效机理,分析AEC-Q200、MIL-PRF-32535、NASA S-311-P-838等标准试验项目,对比PME MLCC与BME MLCC通用规范要求。在鉴定范围和材料结构要求、结构分析和生产一致性、长寿命可靠性、环境适应性等方面,提出了面向方案设计的BME MLCC宇航鉴定关键技术。展开更多
文摘technology for recovering silver and palladium from multilayer ceramic capacitors (MLCC) scraps was studied. 91% silver and 98% palladium are respectively leached from scraps (200 mesh) under the conditions of 4 mol/L HNO_3, 80℃, 2 h (s/l=1∶3). Silver can be precipitated with hydrochloric acid from leaching solutions. Purity of coarse silver bullion obtained from melting silver chloride is 98%. Silver recovery is 88%. Palladium can be reduced and precipitated respectively from silver raffinate and leaching residue scrub solutions by iron powders and butyl xanthate. Purity of palladium is 99.95% by traditional refining method. Palladium recovery is 95%.
文摘The glass-ceramic dielectrics and internal electrode structures are investigated for improving the general energy storage density of capacitors. Calculation indicates that glass-ceramics acquired from glass matrix annealing at 850℃ for 3 hours can be approximately up to 17 J/cm3 in energy storage density. They are appropriately chosen as the dielectrics for preparing high energy storage density capacitors (HESDCs). A series multilayer structure of internal electrode is developed for the HESDCs, in which each layer is a combination of gold film and silver paste. This electrode structure promises the capacitor immune from the residual porosity defects inevitably brought by electrode paste sintering process, and specifically improves the electrical breakdown strength of the capacitor. Based on this new electrode structure, the energy storage densities of capacitors are increased by more than one order of magnitude compared with those traditional ones with only single layer of internal electrode. Thus, HESDCs based on the optimized glass-ceramic dielectrics can potentially achieve 7.5 J/cm3 in energy storage density, even taking into consideration the enlargement of total capacitor volumes while encapsulating practicable capacitors from dielectrics media.
文摘多层陶瓷电容器(MLCCs)体现了电子元器件小型化、复合化、低成本、高可靠性的发展趋势。BME(BaseMetal Electrode)技术的发展促进了 Ni 内电极 MLCCs 的生产和应用。为了适应贱金属 Ni 内电极 MLCCs 还原气氛烧结需要,对介质瓷料提出了抗还原性要求,使其具有高的绝缘电阻率和长的工作寿命。综述了 BaTiO_3 基介质瓷料的抗还原性措施,涉及电子缺陷浓度的降低以及氧空位缺陷迁移的抑制,并利用缺陷化学阐述了其 A 位施主和 B 位受主掺杂的改性机理。
文摘近年来,随着技术逐渐成熟,在欧美等国,BME MLCC已经逐渐进入宇航应用领域。相对传统的PME MLCC,BM E M LCC具有缓慢老化失效模式、介质减薄等特性,也存在可靠性风险。从"初步评估、详细评估、鉴定检验"宇航鉴定思路出发,结合电容器失效模式和失效机理,分析AEC-Q200、MIL-PRF-32535、NASA S-311-P-838等标准试验项目,对比PME MLCC与BME MLCC通用规范要求。在鉴定范围和材料结构要求、结构分析和生产一致性、长寿命可靠性、环境适应性等方面,提出了面向方案设计的BME MLCC宇航鉴定关键技术。
