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Research On Firing Process Of Strontium Barium Titanate-based Materials For Pulsed Multilayer Ceramic Capacitors

Posted on:2024-04-01Degree:MasterType:Thesis
Country:ChinaCandidate:H XuFull Text:PDF
GTID:2531307073465834Subject:Materials Science and Engineering
Abstract/Summary:PDF Full Text Request
With the rapid development of electronic information industry and surface mount technology,pulsed multilayer ceramic capacitors(MLCC),as the core energy storage components of pulsed power systems,are developing toward miniaturization,high capacity and high energy storage,and the sintering temperature of ceramics is required to be lower and lower due to the upgrading of process technology and energy saving and consumption reduction.In addition,since the ceramic dielectric needs to be co-fired with the inner electrode in the MLCC preparation process,the sintering temperature of the ceramic is required to be lowered so that the inner electrode has more selectivity.Therefore,the investigation of ceramic materials with high energy storage density and low sintering temperature has become a hot research topic in pulsed multilayer ceramic capacitors.In this paper,a 0.8Ba0.2Sr0.8Ti O3-0.2Bi(Mg0.5Zr0.5)O3(BST-BMZ)dielectric ceramic with excellent performance is selected as the substrate to reduce the sintering temperature and improve the electrical properties by adding oxide or glass.Cu O was added to the BST-BMZ ceramics as a sintering aid to lower the sintering temperature of the ceramics by the appearance of the liquid phase during the sintering process.The introduction of Cu O reduced the sintering temperature of BST-BMZ from 1300°C to 1150°C.the energy storage density Wrec and energy storage efficiencyηof BST-BMZ-1 wt%Cu O ceramics at a field strength of 240 k V/cm were 1.77 J/cm3 and 88.02%,respectively.Mn O2was added to the BST-BMZ as a sintering aid.After adding 0.3 wt%Mn O2,the sintering temperature was reduced from 1300℃to 1200℃,and the sintering temperature was reduced by about 100℃.In the temperature range of-55~125℃,the change in capacitance was maintained at about 10%,and the temperature stability of the dielectric ceramics was improved.When the addition amount of Mn O2 is 0.3 wt%,the breakdown strength can reach 200 k V/cm,the energy storage density Wrec is 1.16 J/cm3,and the energy storage efficiencyηis 92.8%.Sr O-B2O3-Zn O(SBZ)glass was added to BST-BMZ ceramics to investigate the sintering process and performance.After the addition of glass,during the sintering process,the glass will melt first and form a liquid phase,which has a good wetting effect on the ceramic particles and reduces the sintering temperature of the ceramics.The effects of glass content on the sintering temperature,crystal structure,microstructure,dielectric properties and energy storage properties of BST-BMZ ceramics were investigated.Due to the good wetting effect of SBZ glass melt on BST-BMZ ceramics,the addition of SBZ glass to the BST-BMZ matrix is more favorable to achieve low-temperature sintering,and the sintering temperature of BST-BMZ+2 wt%SBZ ceramics is reduced from 1300°C to 1100°C.The average grain size is reduced and the densification is higher,which is beneficial to enhance the energy storage performance of the dielectric material.BST-BMZ+2 wt%SBZ ceramics have the best overall performance with energy storage density of 2.13 J/cm3 and energy storage efficiency of 94.1%.The results indicate that BST-BMZ+2 wt%SBZ ceramics are a promising dielectric material for pulsed multilayer ceramic capacitors,and the study of ceramic low-temperature sintering provides a certain basis for future practical applications.
Keywords/Search Tags:SrTiO3, Dielectric properties, Energy storage characteristics, Low temperature sintering
PDF Full Text Request
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