共查询到19条相似文献,搜索用时 140 毫秒
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工艺因素对Ba_(6-3x)(Sm_(1-y)Nd_y)_(8+2x)Ti_(18)O_(54)陶瓷微波特性的影响 总被引:7,自引:2,他引:7
探讨了研磨时间,黏合剂浓度、用量,压力,保压时间,预烧温度,烧结温度,烧结时间等工艺因素对Ba6-3x(Sm1-yNdy)8+2xTi18O54陶瓷(x=0.6,y=0.2,0.3)微波性能的影响,试验结果表明,在其他工艺因素控制得当时,预烧温度和烧结温度对微波性能的影响最大。在预烧温度1050℃,烧结温度1200℃下,其微波特性参数εr=76.19,Q·f=10.2THz,(f=4.5GHz)。本系统陶瓷的烧结温度比一般文献低100℃左右,性能仍不错。进一步研究可为制备低温烧结微波陶瓷提供可能。 相似文献
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在肖特基半桥产品的部封装工艺,烧结是影响总和质量和主要工序,而在烧结过程中,烧结温度又是最主要的因素。 相似文献
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冯新环 《电子材料与电子技术》2004,31(4):5-6
本文研究了烧结工艺中800℃放气温度对烧结NdFeB磁体性能的影响。结果指出,随着放气平台温度的提高,可以提高生产效率,增强磁体的一致性,但同时导致磁体矫顽力的降低。研究结果表明选择合适的放气温度平台是烧结工艺中一个重要的因素。 相似文献
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研究了烧结温度对TiO2压敏陶瓷显微结构、晶界势垒结构和电学性能的影响。采用扫描电镜(SEM)测试了不同烧结温度对TiO2陶瓷的显微结构;根据热电子发射理论,采用电学性能数据计算了不同烧结温度的晶界势垒结构;讨论了显微结构和势垒结构对TiO2压敏陶瓷电学性能的影响。实验结果表明:烧结温度必须高于致密化的初始温度,但烧结温度过高会形成大量氧空位而在晶粒中形成气孔,影响显微结构的均匀性和致密性,较适合的烧结温度为1 350℃。随烧结温度的增加,TiO2压敏陶瓷的晶粒尺寸长大,Nb5 的固溶度增加,势垒高度与势垒宽度增加,压敏电压降低,而非线性系数和介电常数增加。 相似文献
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van Pelt J Wolters PS Corner MA Rutten WL Ramakers GJ 《IEEE transactions on bio-medical engineering》2004,51(11):2051-2062
Extracellular action potentials were recorded from developing dissociated rat neocortical networks continuously for up to 49 days in vitro using planar multielectrode arrays. Spontaneous neuronal activity emerged toward the end of the first week in vitro and from then on exhibited periods of elevated firing rates, lasting for a few days up to weeks, which were largely uncorrelated among different recording sites. On a time scale of seconds to minutes, network activity typically displayed an ongoing repetition of distinctive firing patterns, including short episodes of synchronous firing at many sites (network bursts). Network bursts were highly variable in their individual spatio-temporal firing patterns but showed a remarkably stable underlying probabilistic structure (obtained by summing consecutive bursts) on a time scale of hours. On still longer time scales, network bursts evolved gradually, with a significant broadening (to about 2 s) in the third week in vitro, followed by a drastic shortening after about one month in vitro. Bursts at this age were characterized by highly synchronized onsets reaching peak firing levels within less than ca. 60 ms. This pattern persisted for the rest of the culture period. Throughout the recording period, active sites showed highly persistent temporal relationships within network bursts. These longitudinal recordings of network firing have, thus, brought to light a reproducible pattern of complex changes in spontaneous firing dynamics of bursts during the development of isolated cortical neurons into synaptically interconnected networks. 相似文献
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The firing atmosphere (air, oxygen, and argon) was found to affect the electrical and mechanical properties of an air-fireable
electrically conductive glass-free silver-based thick film. For the optimum firing temperature of 930°C, air results in the
lowest resistivity, but a minor amount of pinholes; oxygen results in the largest thickness, the smoothest surface, and no
pinhole; and argon results in the highest resistivity, large pinholes, the smallest thickness, vanishing of macroscopic parts
of the film, and the poorest scratch resistance. Argon gives higher resistivity than air or oxygen at essentially all firing
temperatures. 相似文献
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高立影 《电子工业专用设备》2012,41(9):35-40
针对目前蓬勃发展的DBC技术,而专门研制的气氛网带烧结炉,可用于DBC的高温烧结及预氧化,同时,该气氛网带烧结炉关键点的氧含量均可控可调,充分满足了DBC的整个流程工艺。 相似文献
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V. I. Egorkin V. E. Zemlyakov A. V. Nezhentsev V. I. Garmash 《Russian Microelectronics》2017,46(4):272-276
This paper investigates ohmic contacts to n-GaAs layers of the heterobipolar nanoheterostructures obtained through electron-beam evaporation of Ge, Au, Ni, and Au layer-by-layer. The effect of the firing time and temperature on the contact resistance is considered. Based on the analysis of the characteristics of the ohmic contacts, a firing installation of a special design and a firing technique are developed. The technique ensures the minimum contact resistance for the minimum size of a transition layer, satisfactory morphology, and even edges of the contacts. 相似文献