低介電常數(shù)、溫度補(bǔ)償型MLCC材料介電性能研究
發(fā)布時間：2019-02-22 15:03
【摘要】：Multi-layers Ceramic Capacitor(縮寫為MLCC)片式疊層陶瓷電容器以其優(yōu)良的性能、成熟的制作工藝、相對低的生產(chǎn)成本,逐漸成為電容器市場的主要產(chǎn)品,因而MLCC材料也是近年來的研究熱點。而低介電常數(shù)的微波介電材料,既能滿足MLCC高精度、高頻率的實際應(yīng)用需求,又具有高品質(zhì)因素(Q)、超低的串聯(lián)等效電阻(ESR),正逐漸被市場所重視。本文應(yīng)風(fēng)華高科一研究課題需求,探索研制能與Ni電極在還原性氣氛中共燒依然具有良好性能的低介電MLCC材料。綜合考慮生產(chǎn)成本與材料性能,選定Mg2SiO4體系陶瓷為研究對象,通過摻雜取代等一系列改性方法,調(diào)試其各項介電性能指標(biāo),并運用XRD、SEM、阻抗分析、鐵電性能測試以及諧振腔測試方法,探究各項試驗方案對材料介電性能的影響規(guī)律,并最終制得滿足性能需求的介電陶瓷材料。1.選取Mg2SiO4體系陶瓷為研究對象,采用固相法合成,通過制備工藝的改進(jìn),例如分散劑的選取、球磨時間的設(shè)定以及配料中Mg/Si化學(xué)計量數(shù)之比的改變,來抑制雜相MgSiO3的產(chǎn)生從而提高材料的介電性能。最終確定以去離子水作分散劑、球磨5h、Mg/Si=2.075時,陶瓷經(jīng)1400°C燒結(jié)后具有良好的微波介電性能:εr=7.5,Q×f=85346 GHz,τf=-60ppm/°C。2.通過Zn取代Mg改性的方式,進(jìn)一步提高陶瓷材料的介電性能,并降低燒結(jié)溫度。以(ZnxMg1-x)2SiO4體系為研究對象,通過不同的取代比例(x=0.2、0.4、0.6、0.8、0.9)對比試驗,最終確定(Zn0.9Mg0.1)2SiO4(x=0.9)為該體系中最佳的成分比例,經(jīng)1350°C燒結(jié)3h后獲得致密結(jié)構(gòu)、低頻介電性能:εr=7.3,tanδ≈10-5,τε≈100ppm/°C(f=1MHz)以及微波介電性能:εr=6.7,Q×f=71,955 GHz,τf=-52ppm/°C。3.為改善(Zn0.9Mg0.1)2SiO4陶瓷的介電常數(shù)溫度特性以便更好地應(yīng)用于實際電路中,本文通過添加Ba取代Zn進(jìn)行調(diào)節(jié)。添加Ba取代Zn以制備(Zn0.9-xMg0.1Bax)2SiO4(x=0.025、0.05、0.1、0.2)陶瓷,隨著Ba的添加,體系中出現(xiàn)BaZn2Si2O7第二相,經(jīng)過一系列的性能測試,發(fā)現(xiàn)該相具有鐵電性,(Zn0.9-xMg0.1Bax)2SiO4陶瓷在40°C左右出現(xiàn)居里溫度點,隨著Ba含量的增加,BaZn2Si2O7成分逐漸增加,使得燒結(jié)溫度降低,提高介電常數(shù),并能有效的調(diào)節(jié)介電常數(shù)溫度系數(shù)τε。并且,當(dāng)x=0.05時,1230°C燒結(jié)可以獲得近零的τε= 10.5 ppm/°C以及較好的致密性和介電性能:ρ=4.14g/cm3εr=9.97,tanδ=8.7×10-4(f=1MHz)。由于該體系中元素價態(tài)穩(wěn)定,在還原性氣氛中燒結(jié)測試后也能獲得較好的性能。制備中出現(xiàn)的新相BaZn2Si2O7具有較大的負(fù)τε值,并且價態(tài)穩(wěn)定,有希望應(yīng)用于BME-MLCC陶瓷材料需要補(bǔ)償介電溫度特性情況中。而最終制備的(Zn0.85Mg0.1Ba0.05)2SiO4陶瓷材料以其合適的性能指標(biāo),穩(wěn)定的結(jié)構(gòu)以及價態(tài),有潛力應(yīng)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 擄C had good microwave dielectric properties: 蔚 rn 7.5 Q 脳 FU 85346 GHz, 蟿 f=-60ppm/ 擄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 擄C for 3 h, the compact structure was obtained. The low frequency dielectric properties were 蔚 rn 7.3n 未 鈮，
本文編號：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 擄C had good microwave dielectric properties: 蔚 rn 7.5 Q 脳 FU 85346 GHz, 蟿 f=-60ppm/ 擄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 擄C for 3 h, the compact structure was obtained. The low frequency dielectric properties were 蔚 rn 7.3n 未 鈮，
本文編號：2428341
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