本文選題：微波介質陶瓷 + 低溫燒結��； 參考：《桂林理工大學》2016年碩士論文

【摘要】：隨著無線通訊設備不斷向小尺寸、集成化方向發(fā)展,微波介質陶瓷材料不僅需要適當?shù)慕殡姵?shù)(εr),高的品質因素(Q×f)以及較低的諧振頻率溫度系數(shù)(τf),同時也需要有較低的燒結溫度,以便與低熔點的電極共燒,滿足LTCC(低溫共燒陶瓷)技術的要求。本文通過傳統(tǒng)的固相反應法制備了5Mg_O-3Li2_O-4W_O_3、Li_4xMg_(3(1-x))Al_(6(1-x))Ti_5O_(12)、Li_4Ti_5O_(12)等新型低溫燒結微波介質陶瓷,系統(tǒng)研究了LiZnNbO_4陶瓷的低溫化燒結、工藝優(yōu)化、燒結特性及性能調節(jié),并對上述陶瓷與Ag電極的低溫共燒進行了初步探討。(1)采用傳統(tǒng)的固相反應法制備了5MgO-3Li_2O-4WO_3新型低燒微波介質陶瓷,通過XRD、SEM以及微波網(wǎng)絡分析儀研究了該陶瓷的相結構、原子占位、燒結性能及微波介電性能。5Mg O-3Li_2O-4WO_3陶瓷不僅具有低的燒結溫度(≤840 oC),而且還具有低介電常數(shù)~10.3,高品質因素~20,537 GHz(在~11GHz頻率下)。該材料能與Ag共燒兼容,表明其可作為LTCC器件的備選材料。(2)對比研究了不同原材料處理方式對Li Zn Nb O4陶瓷相轉變、顯微結構、燒結特性及微波介電性能的影響,恰當?shù)脑牧咸幚硎沟肔i Zn Nb O4陶瓷在一個較低的溫度區(qū)間(950~1070 oC)獲得高的品質因數(shù)(Q×f),改善了Li Zn Nb O4陶瓷的燒結特性,并降低其燒結溫度。加入一定量的Ca Ti O_3來調節(jié)Li Zn Nb O_4陶瓷的τf,1070 oC燒結的0.9Li Zn Nb O_（4-0.1）Ca Ti O_3陶瓷具有優(yōu)異的微波介電性能:εr=22.9,Q×f=10,583 GHz(諧振頻率f~7.4 GHz),τf=-27.5 ppm/oC。(3)研究了Li_4xMg_(3(1-x))Al_(6(1-x))Ti_(5x) O_(12)(0.2≤x≤0.8)微波介質陶瓷體系的相結構、微觀形貌及微波介電性能。Li_(4x)Mg_(3(1-x))Al_(6(1-x))Ti_(5x) O_(12)(0.2≤x≤0.8)陶瓷表現(xiàn)出良好的綜合性能:εr=11.5~26.5,Q×f=7,102~30,191 GHz,τf=-55.4~+5.7 ppm/°C,燒結溫度可以從1280 oC降低至925°C。值得注意的是,Li_(4x)Mg_(3(1-x))Al_(6(1-x))Ti_(5x) O_(12)(x=0.6)陶瓷在1075°C時燒結顯示出中等的εr~18.8,高Q×f~12,429 GHz(諧振頻率f~8 GHz),近零的τf~-6.0 ppm/°C。(4)通過傳統(tǒng)的固相法制備了新型Li4Ti5O12低燒微波介質陶瓷,并對其相結構、燒結特性、微觀晶粒形貌以及微波介電性能進行了較為系統(tǒng)的研究。XRD分析表明其具有立方尖晶石結構(JCPDS file No.00-049-0207)。該陶瓷在925°C燒結時,獲得最佳的微波介電性能:中等介電常數(shù)~31.5,高品質因數(shù)(Q×f)~29,530 GHz(諧振頻率f~7GHz),以及小的諧振頻率溫度系數(shù)(τf)~-15.0 ppm/°C。當燒結溫度上升到1025°C以上,析出的Ti O2相使得混和相的諧振頻率溫度系數(shù)調節(jié)近零。
[Abstract]:With the development of wireless communication equipment to the direction of small size and integration, Microwave dielectric ceramic materials need not only proper dielectric constant (蔚 r),) high quality factor (Q 脳 f) and lower resonant frequency temperature coefficient (蟿 f), but also lower sintering temperature to co-burn with low melting point electrode. Meet the requirements of LTCC (low temperature co-fired ceramics) technology. In this paper, a new type of low-temperature sintering microwave dielectric ceramics, such as 5MgO-3Li2SnO-4WSP, Li4xMg3 (1-x) Al6 (1-x) Ti5O12 / Li4Ti5O12, has been prepared by traditional solid state reaction method. The low temperature sintering, process optimization, sintering characteristics and performance adjustment of LiZnNbO4 ceramics have been systematically studied. The low temperature co-firing of the above ceramics with Ag electrode was discussed. (1) 5MgO-3Li2O-4WO3 microwave dielectric ceramics were prepared by conventional solid state reaction. The phase structure and atomic occupation of the ceramics were studied by XRDX SEM and microwave network analyzer. Sintered and microwave dielectric properties. 5mg O-3Li2O-4WOS3 ceramics not only have low sintering temperature (鈮，

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