The La-Co substituted Sr1–xLaxFe12–xCoxO19 (x=0–0.5) ferrites with appropriate Bi2O3 additive were prepared by conventional sintering method and microwave sintering method at low sintering temperatures compatible w...The La-Co substituted Sr1–xLaxFe12–xCoxO19 (x=0–0.5) ferrites with appropriate Bi2O3 additive were prepared by conventional sintering method and microwave sintering method at low sintering temperatures compatible with LTCC (low temperature co-fired ceramics) systems, and their sintering behavior was chiefly investigated, including the crystal structure, saturation magnetizationMs, magnetic anisotropy fieldHa, intrinsic coercivityHci, and Curie temperatureTC. Experiment results clearly showed that the pure M-type crystal phase was successfully obtained when the La-Co substitution amountx did not exceed 0.3. However, the single M-type phase structure transformed to multiphase structure with further increased x, where the M-type phase coexisted with the non-magnetic phase such asα-Fe2O3 phase, La2O3 phase, and LaCoO3 phase. Appropriate La-Co substitution improved theMs (>62 emu/g),Ha (>1400 kA/m), andHci (>320 kA/m) for the ferrites withx varying from 0.1 to 0.3, but theTC decreased with increasing substitution amount. More-over, the microwave sintered ferrites could provide largerHci and similarMs compared with the conventional sintered ferrites.展开更多
在集成散热微流道的低温共烧陶瓷(low-temperature co-fired ceramics,LTCC)封装基板中引入内嵌金属柱(embedded metal columns,EMCs)作为导热增强结构,是提升封装体散热性能的重要改进措施。基于已有的理论分析与试验研究结果,结合工...在集成散热微流道的低温共烧陶瓷(low-temperature co-fired ceramics,LTCC)封装基板中引入内嵌金属柱(embedded metal columns,EMCs)作为导热增强结构,是提升封装体散热性能的重要改进措施。基于已有的理论分析与试验研究结果,结合工艺条件,分析内嵌金属柱截面形状、长度、直径和流体入口流速对其散热性能的影响。通过正交试验设计,在有限元仿真软件中建立带有内嵌金属柱的LTCC微流道基板的热仿真模型,并对得到的热仿真数据进行极差与方差分析。研究结果表明,影响内嵌金属柱散热性能的因素由大到小依次为流体流速、内嵌金属柱截面形状、内嵌金属柱直径以及内嵌金属柱长度;在置信度为90%的情况下,流体入口流速、内嵌金属柱截面形状和直径均对其散热性能有显著影响,内嵌金属柱长度对其散热性能无显著影响。展开更多
低温共烧陶瓷(Low Temperature Co-fired Ceramics,LTCC)技术是最具潜力的三维立体封装技术之一,随着其导体浆料由金浆料向银、铜浆料发展,为防止基板内导线在烧成后因氧化或电迁移失效,化学镀镍钯金已成为LTCC基板制造中的重要步骤。...低温共烧陶瓷(Low Temperature Co-fired Ceramics,LTCC)技术是最具潜力的三维立体封装技术之一,随着其导体浆料由金浆料向银、铜浆料发展,为防止基板内导线在烧成后因氧化或电迁移失效,化学镀镍钯金已成为LTCC基板制造中的重要步骤。为减轻化学镀工艺中酸、碱、水溶液对LTCC材料的侵蚀,确保器件的可靠性,低成本、高可靠的LTCC基板材料必须具备优异的耐化学腐蚀能力。基于化学镀工艺背景,本文对LTCC基板材料在酸碱环境中的腐蚀问题展开综述,分析LTCC基板材料的典型腐蚀行为与失效案例,并揭示其共性规律,系统总结LTCC用烧结助剂玻璃在不同酸碱腐蚀环境下成分-结构-耐蚀性之间的内在关联,进一步探讨了可化学镀LTCC基板材料用烧结助剂玻璃材料的设计思路,为低成本、高可靠LTCC材料的开发提供了理论支撑。展开更多
The implementation and characteristics of a compact lumped-element three-order low pass filter are presented in this paper. The filter with 120 MHz cut off frequency, as well as more than 20 dB of the attenuation abov...The implementation and characteristics of a compact lumped-element three-order low pass filter are presented in this paper. The filter with 120 MHz cut off frequency, as well as more than 20 dB of the attenuation above 360 MHz frequency band is successfully manufactured in an LTCC substrate with 40 pm layer thickness. The overall size of the filter is 2.0 mm×1.2 mm×0.9 mm. A good coincidence between the measured results and the full-wave electromagnetic designed responses is observed.展开更多
具有多层异质结构(金属布线层与陶瓷层等)的低温共烧陶瓷(low temperature co-fired ceramic, LTCC)基板是一种重要的集成封装部件,对其力学性能进行深入研究具有重要科学意义。针对6种具有不同异质集成结构的LTCC基板断裂行为进行了测...具有多层异质结构(金属布线层与陶瓷层等)的低温共烧陶瓷(low temperature co-fired ceramic, LTCC)基板是一种重要的集成封装部件,对其力学性能进行深入研究具有重要科学意义。针对6种具有不同异质集成结构的LTCC基板断裂行为进行了测试,获得了其极限弯曲强度。在此基础上,通过有限元仿真方法对其变形模式进行了探讨,并确定了最大主应力位置以及最先发生断裂行为的应力分布规律。研究结果表明,仿真结果与实测数据相对误差均在5%以内,具有良好一致性;当压载荷存在时,多层异质集成LTCC基板的裂纹扩展位置不同,其中,空腔四角处应力最大,具有该结构的基板极限弯曲强度最差。该研究为多层异质集成LTCC基板机械强度的提升提供了有效的实验和理论基础。展开更多
基金supported by the National Public Welfare Fund Industry Research(201410026)Scientific Research Foundation of Education Office of Sichuan Province(13Z198)the Young and Middle-aged Academic Leaders of Scientific Research Funds of Chengdu University of Information Technology(J201222)
文摘The La-Co substituted Sr1–xLaxFe12–xCoxO19 (x=0–0.5) ferrites with appropriate Bi2O3 additive were prepared by conventional sintering method and microwave sintering method at low sintering temperatures compatible with LTCC (low temperature co-fired ceramics) systems, and their sintering behavior was chiefly investigated, including the crystal structure, saturation magnetizationMs, magnetic anisotropy fieldHa, intrinsic coercivityHci, and Curie temperatureTC. Experiment results clearly showed that the pure M-type crystal phase was successfully obtained when the La-Co substitution amountx did not exceed 0.3. However, the single M-type phase structure transformed to multiphase structure with further increased x, where the M-type phase coexisted with the non-magnetic phase such asα-Fe2O3 phase, La2O3 phase, and LaCoO3 phase. Appropriate La-Co substitution improved theMs (>62 emu/g),Ha (>1400 kA/m), andHci (>320 kA/m) for the ferrites withx varying from 0.1 to 0.3, but theTC decreased with increasing substitution amount. More-over, the microwave sintered ferrites could provide largerHci and similarMs compared with the conventional sintered ferrites.
文摘在集成散热微流道的低温共烧陶瓷(low-temperature co-fired ceramics,LTCC)封装基板中引入内嵌金属柱(embedded metal columns,EMCs)作为导热增强结构,是提升封装体散热性能的重要改进措施。基于已有的理论分析与试验研究结果,结合工艺条件,分析内嵌金属柱截面形状、长度、直径和流体入口流速对其散热性能的影响。通过正交试验设计,在有限元仿真软件中建立带有内嵌金属柱的LTCC微流道基板的热仿真模型,并对得到的热仿真数据进行极差与方差分析。研究结果表明,影响内嵌金属柱散热性能的因素由大到小依次为流体流速、内嵌金属柱截面形状、内嵌金属柱直径以及内嵌金属柱长度;在置信度为90%的情况下,流体入口流速、内嵌金属柱截面形状和直径均对其散热性能有显著影响,内嵌金属柱长度对其散热性能无显著影响。
文摘低温共烧陶瓷(Low Temperature Co-fired Ceramics,LTCC)技术是最具潜力的三维立体封装技术之一,随着其导体浆料由金浆料向银、铜浆料发展,为防止基板内导线在烧成后因氧化或电迁移失效,化学镀镍钯金已成为LTCC基板制造中的重要步骤。为减轻化学镀工艺中酸、碱、水溶液对LTCC材料的侵蚀,确保器件的可靠性,低成本、高可靠的LTCC基板材料必须具备优异的耐化学腐蚀能力。基于化学镀工艺背景,本文对LTCC基板材料在酸碱环境中的腐蚀问题展开综述,分析LTCC基板材料的典型腐蚀行为与失效案例,并揭示其共性规律,系统总结LTCC用烧结助剂玻璃在不同酸碱腐蚀环境下成分-结构-耐蚀性之间的内在关联,进一步探讨了可化学镀LTCC基板材料用烧结助剂玻璃材料的设计思路,为低成本、高可靠LTCC材料的开发提供了理论支撑。
基金This work was supported by the National Nature Science Foundation of China under Grant No. 60425102.
文摘The implementation and characteristics of a compact lumped-element three-order low pass filter are presented in this paper. The filter with 120 MHz cut off frequency, as well as more than 20 dB of the attenuation above 360 MHz frequency band is successfully manufactured in an LTCC substrate with 40 pm layer thickness. The overall size of the filter is 2.0 mm×1.2 mm×0.9 mm. A good coincidence between the measured results and the full-wave electromagnetic designed responses is observed.
文摘具有多层异质结构(金属布线层与陶瓷层等)的低温共烧陶瓷(low temperature co-fired ceramic, LTCC)基板是一种重要的集成封装部件,对其力学性能进行深入研究具有重要科学意义。针对6种具有不同异质集成结构的LTCC基板断裂行为进行了测试,获得了其极限弯曲强度。在此基础上,通过有限元仿真方法对其变形模式进行了探讨,并确定了最大主应力位置以及最先发生断裂行为的应力分布规律。研究结果表明,仿真结果与实测数据相对误差均在5%以内,具有良好一致性;当压载荷存在时,多层异质集成LTCC基板的裂纹扩展位置不同,其中,空腔四角处应力最大,具有该结构的基板极限弯曲强度最差。该研究为多层异质集成LTCC基板机械强度的提升提供了有效的实验和理论基础。
