低介电常数、温度补偿型MLCC材料介电性能研究
发布时间：2019-02-22 15:03
【摘要】：Multi-layers Ceramic Capacitor(缩写为MLCC)片式叠层陶瓷电容器以其优良的性能、成熟的制作工艺、相对低的生产成本,逐渐成为电容器市场的主要产品,因而MLCC材料也是近年来的研究热点。而低介电常数的微波介电材料,既能满足MLCC高精度、高频率的实际应用需求,又具有高品质因素(Q)、超低的串联等效电阻(ESR),正逐渐被市场所重视。本文应风华高科一研究课题需求,探索研制能与Ni电极在还原性气氛中共烧依然具有良好性能的低介电MLCC材料。综合考虑生产成本与材料性能,选定Mg2SiO4体系陶瓷为研究对象,通过掺杂取代等一系列改性方法,调试其各项介电性能指标,并运用XRD、SEM、阻抗分析、铁电性能测试以及谐振腔测试方法,探究各项试验方案对材料介电性能的影响规律,并最终制得满足性能需求的介电陶瓷材料。1.选取Mg2SiO4体系陶瓷为研究对象,采用固相法合成,通过制备工艺的改进,例如分散剂的选取、球磨时间的设定以及配料中Mg/Si化学计量数之比的改变,来抑制杂相MgSiO3的产生从而提高材料的介电性能。最终确定以去离子水作分散剂、球磨5h、Mg/Si=2.075时,陶瓷经1400°C烧结后具有良好的微波介电性能:εr=7.5,Q×f=85346 GHz,τf=-60ppm/°C。2.通过Zn取代Mg改性的方式,进一步提高陶瓷材料的介电性能,并降低烧结温度。以(ZnxMg1-x)2SiO4体系为研究对象,通过不同的取代比例(x=0.2、0.4、0.6、0.8、0.9)对比试验,最终确定(Zn0.9Mg0.1)2SiO4(x=0.9)为该体系中最佳的成分比例,经1350°C烧结3h后获得致密结构、低频介电性能:εr=7.3,tanδ≈10-5,τε≈100ppm/°C(f=1MHz)以及微波介电性能:εr=6.7,Q×f=71,955 GHz,τf=-52ppm/°C。3.为改善(Zn0.9Mg0.1)2SiO4陶瓷的介电常数温度特性以便更好地应用于实际电路中,本文通过添加Ba取代Zn进行调节。添加Ba取代Zn以制备(Zn0.9-xMg0.1Bax)2SiO4(x=0.025、0.05、0.1、0.2)陶瓷,随着Ba的添加,体系中出现BaZn2Si2O7第二相,经过一系列的性能测试,发现该相具有铁电性,(Zn0.9-xMg0.1Bax)2SiO4陶瓷在40°C左右出现居里温度点,随着Ba含量的增加,BaZn2Si2O7成分逐渐增加,使得烧结温度降低,提高介电常数,并能有效的调节介电常数温度系数τε。并且,当x=0.05时,1230°C烧结可以获得近零的τε= 10.5 ppm/°C以及较好的致密性和介电性能:ρ=4.14g/cm3εr=9.97,tanδ=8.7×10-4(f=1MHz)。由于该体系中元素价态稳定,在还原性气氛中烧结测试后也能获得较好的性能。制备中出现的新相BaZn2Si2O7具有较大的负τε值,并且价态稳定,有希望应用于BME-MLCC陶瓷材料需要补偿介电温度特性情况中。而最终制备的(Zn0.85Mg0.1Ba0.05)2SiO4陶瓷材料以其合适的性能指标,稳定的结构以及价态,有潜力应用于BME-MLCC陶瓷材料中。
[Abstract]:Multi-layers Ceramic Capacitor (MLCC) laminated ceramic capacitors have become the main products in capacitor market for their excellent performance, mature manufacturing process and relatively low production cost. Therefore, MLCC materials have been a hot research topic in recent years. Microwave dielectric materials with low dielectric constant can meet the practical application demand of high precision and high frequency of MLCC, and the series equivalent resistance (ESR), with high quality factor (Q), is being paid more and more attention by the market. In this paper, according to the demand of Fenghua Hi-Tech, we have explored the development of low dielectric MLCC material which can be co-fired with Ni electrode in reducing atmosphere. Considering the production cost and material properties, the ceramics of Mg2SiO4 system were selected as the research object. The dielectric properties of the ceramics were tested by a series of modification methods, such as doping and substitution, and the XRD,SEM, impedance analysis was used. The methods of ferroelectric property test and resonant cavity test were used to investigate the influence of each test scheme on the dielectric properties of the materials. Finally, the dielectric ceramic materials satisfying the performance requirements were prepared. 1. The ceramics of Mg2SiO4 system were selected as the research object and synthesized by solid phase method. Through the improvement of preparation process, such as the selection of dispersant, the setting of ball milling time and the change of the ratio of Mg/Si stoichiometry in the mixture, In order to inhibit the generation of heterogenous MgSiO3 and improve the dielectric properties of the materials. When deionized water was used as dispersant and mg / Si = 2.075 was milled for 5 h, the ceramics sintered at 1400 掳C had good microwave dielectric properties: 蔚 rn 7.5 Q 脳 FU 85346 GHz, 蟿 f=-60ppm/ 掳C. 2. The dielectric properties and sintering temperature of ceramic materials were further improved by replacing Mg with Zn. The (ZnxMg1-x) 2SiO4 system was used as the research object, and the best component ratio of (Zn0.9Mg0.1) 2SiO4 (x0. 9) was determined by the contrast test of the different substitution ratio (x0. 2 ~ 0. 4 ~ 0. 6 ~ 0. 6 ~ 0. 8 ~ 0. 9), and the results showed that (Zn0.9Mg0.1) 2SiO4 (x-0. 9) was the best component in the system. After sintering at 1350 掳C for 3 h, the compact structure was obtained. The low frequency dielectric properties were 蔚 rn 7.3n 未 鈮，
本文编号：2428341
[Abstract]:Multi-layers Ceramic Capacitor (MLCC) laminated ceramic capacitors have become the main products in capacitor market for their excellent performance, mature manufacturing process and relatively low production cost. Therefore, MLCC materials have been a hot research topic in recent years. Microwave dielectric materials with low dielectric constant can meet the practical application demand of high precision and high frequency of MLCC, and the series equivalent resistance (ESR), with high quality factor (Q), is being paid more and more attention by the market. In this paper, according to the demand of Fenghua Hi-Tech, we have explored the development of low dielectric MLCC material which can be co-fired with Ni electrode in reducing atmosphere. Considering the production cost and material properties, the ceramics of Mg2SiO4 system were selected as the research object. The dielectric properties of the ceramics were tested by a series of modification methods, such as doping and substitution, and the XRD,SEM, impedance analysis was used. The methods of ferroelectric property test and resonant cavity test were used to investigate the influence of each test scheme on the dielectric properties of the materials. Finally, the dielectric ceramic materials satisfying the performance requirements were prepared. 1. The ceramics of Mg2SiO4 system were selected as the research object and synthesized by solid phase method. Through the improvement of preparation process, such as the selection of dispersant, the setting of ball milling time and the change of the ratio of Mg/Si stoichiometry in the mixture, In order to inhibit the generation of heterogenous MgSiO3 and improve the dielectric properties of the materials. When deionized water was used as dispersant and mg / Si = 2.075 was milled for 5 h, the ceramics sintered at 1400 掳C had good microwave dielectric properties: 蔚 rn 7.5 Q 脳 FU 85346 GHz, 蟿 f=-60ppm/ 掳C. 2. The dielectric properties and sintering temperature of ceramic materials were further improved by replacing Mg with Zn. The (ZnxMg1-x) 2SiO4 system was used as the research object, and the best component ratio of (Zn0.9Mg0.1) 2SiO4 (x0. 9) was determined by the contrast test of the different substitution ratio (x0. 2 ~ 0. 4 ~ 0. 6 ~ 0. 6 ~ 0. 8 ~ 0. 9), and the results showed that (Zn0.9Mg0.1) 2SiO4 (x-0. 9) was the best component in the system. After sintering at 1350 掳C for 3 h, the compact structure was obtained. The low frequency dielectric properties were 蔚 rn 7.3n 未 鈮，
本文编号：2428341
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