Low Temperature Sintering Of CaZrO₃ Microwave Dielectric Ceramics With Bismuth Borate Ternary System

In recently years,with the rapid development of modern mobile communication technology, microwave dielectric ceramic as a new kind of functional ceramics, which has been strongly required that the related components tend to miniaturization and integration. In order to meet these requirements, low temperature co-fired ceramics(LTCC) technology get rapid development. But at present, commonly used microwave dielectric ceramic sintering temperature are mostly in more than 1300℃. From the view points of cost saving and environmental protection, request ceramics with low sintering temperature(below 900℃),in order to co-fired with base metal materials such as Ag(960℃) or Cu(1084℃) electrode. Add sintering aids use of liquid phase sintering was the most commonly for low temperature sintering.Ba O-Bi2O3-B2O3(BBB)and Bi2O3-Zn O-B2O3(BZB) are kinds of compound with low melting point.The glass softening point is low, which could be formed glass at lower temperature.It can be as sintering aids add to microwave dielectric ceramics for its low melting point, mixed with ceramic powder and sintering at lower temperature.Ca Zr O3 ceramics have a good practical value for its suitable dielectric constant and low dielectric loss as capacitors and dielectric resonator.However, its sintering temperature is particularly high, which increases the cost of production in the practical application. Therefore, this dissertation system study of BBB and BZB ternary compound,study its microwave dielectric properties after sintering at different temperature and reveal the sintering additives selection rule. Therefore, Ca Zr O3 microwave dielectric ceramics were selected as the investigate objects in this article. The BBB、BZB were added Ca Zr O3 ceramics by solid phase mix method, reveal the effects of different sintering aids on phase compositions, sintering characteristics, microstructures and dielectric properties. The main research results are as follows:1. The Ba O- Bi2O3- B2O3(BBB) ternary compound has excellent microwave dielectric properties:εr=17.9,Q×f=6720GHz,τf=29×10-6/℃ were obtained when Ba Bi10B6O25 sintered at 600°C for 3h.2. The Bi2O3-Zn O-B2O3(BZB) ternary compound has excellent microwave dielectric properties : εr=18.6, Q×f=6774GHz, τf=-18×10-6/ ℃ were obtained when Bi2 Zn B2O7 sintered at 650°C for 3h.3. Pure Ca Zr O3 ceramics in 1550 ℃ sintering densification 3 h, the microwave dielectric properties of εr=30, Q×f=15000GHz, τf=-26.5×10-6/℃. By adding the BBB and BZB sintering additives can effectively reduce the sintering temperature, and maintain good microwave dielectric properties, which can research of Ca Zr O3 ceramics sintering performance and the influence of microwave dielectric properties.(1) Add BBB Ca Zr O3 ceramics sintering temperature can be reduced from 1550 ℃ to 1000 oC. The excellent microwave dielectric properties of εr=28,Q×f =8872GHz,τf=21×10-6/℃ were obtained when w(Ba Bi10B6O25)=7.5% Ba Bi10B6O25-Ca Zr O3 ceramics sintered at 1000°C for 3h.(2) Add BZB Ca Zr O3 ceramics sintering temperature can be reduced from 1550 ℃ to 950 oC. The excellent microwave dielectric properties of εr=29,Q×f =8956GHz, τf=-16×10-6/ ℃ were obtained w(Bi2Zn B2O7)=6% Bi2 Zn B2O7-Ca Zr O3 ceramics sintered at 950°C for 3h.4. Add sintering aids BBB、BZB and LBS、ZBS glass all can reduce the sintering temperature of Ca Zr O3 ceramics, achieve Low temperature sintering. The 7 kinds of BBB sintering aids cooling effect are small, Ba Bi10B6O25 has optimum microwave dielectric properties after sintered. Cooling effect of BBB、BZB and LBS 、 ZBS glass are small, all can as sintering aids add in ceramics for low temperature sintering.