Research On High Performance Phosphate And Borate LTCC Material And Its Application

With the help of the solid-state reaction experiment and the first principle calculation,theεr,Q×f,τf,and sintering property of Zn3B2O6 and LiZnPO4 ceramics have been modified.The matching co-firing model of heterogeneous ceramic with different dielectric constant has been proposed using the finite element simulation.The shrinkage,shrinkage rate,and shrinkage window of heterogeneous ceramic were matched.A common mode filter with excellent performance has been prepared based on the ceramic and the matching co-firing technology proposed in this work.The specific research content of this dissertation is as follows:The sintering and dielectric properties of Zn3B2O6 ceramic have been researched by ion substitution.Firstly,a large amount of Mg²⁺has been used to substitute the Zn²⁺of Zn3B2O6,and a composite material with Zn3B2O6,Mg2B2O5,and Zn O was obtained.Ion substitution happened in the crystal of Zn3B2O6 and Mg2B2O5 ceramics.The sintering,substitution,and phase formation properties have been researched based on the system energy parameter.The peak dielectric property has been obtained when x=0.20 and sintered at 950℃,that areεr=6.17,Q×f=89600 GHz,τf=-48.6 ppm/℃,and relative density=96.7%.Secondly,a small amount of Mn²⁺has been used to substitute the Zn²⁺of Zn3B2O6.The Zn3 site is most likely to be occupied.The dielectric and sintering properties of Zn3B2O6 ceramic have been improved,and the peak value has been obtained when x=0.04 and sintered at 900℃,that are Q×f=88100 GHz,εr=6.58,τf=-56.5 ppm/°C,and relative density=96.7%.Besides,the activation energy and densification temperature have decreased.Thirdly,a small amount of Ni²⁺has been used to substitute the Zn²⁺of Zn3B2O6.The Zn1 site has the priority to be occupied by nickel.The activation energy and densification temperature have decreased,and the sintering property has been modified.The densification level and dielectric property have been improved.The peak dielectric property has been obtained when x=0.05 and sintered at 900℃,that are Q×f=91000 GHz,εr=6.9,τf=-55.6 ppm/°C,and relative density=97.1%.Fourthly,using the Ti O2 to adjust theτf of（Zn0.96Mn0.04）3B2O6 and（Zn0.95Ni0.05）3B2O6 ceramics has been tried.The Ti O2 has reacted with the main phase and formed the Zn2Ti O4 and Zn4B6O13ceramics,leading to the failure ofτf adjusting.The manganese and nickel ions moved from Zn3B2O6 ceramic to Zn2Ti O4 ceramic with the addition of Ti O2.Besides,the Q×f of the ceramic has decreased,and the sintering temperature andεr have increased.The densest sample was obtained when x=0.32 and sintered at 925°C,that are relative density=96.2%,Q×f=28400 GHz,εr=8.07,τf=-55.3 ppm/°C for0.68（Zn0.96Mn0.04）3B2O6+0.32Ti O2 ceramic,and relative density=95.5%,Q×f=29200GHz,εr=8.12,τf=-53.7 ppm/°C for 0.68（Zn0.95Ni0.05）3B2O6+0.32Ti O2 ceramic.The sintering and dielectric properties of ion-substituted LiZnPO4 ceramic have been researched.Firstly,a small amount of Ni²⁺has been used to substitute the Zn²⁺of LiZnPO4 ceramic.The bond population of Zn O4 has decreased.The densification temperature decreased,and the densification level and dielectric property have been improved.The peak dielectric property has been obtained when x=0.04 and sintered at825℃,that areεr=5.57,Q×f=63951 GHz,τf=-79.5 ppm/°C,and relative density=97.27%.Secondly,a large amount of Mn²⁺has been used to substitute the Zn²⁺of LiZnPO4 ceramic,and a solid solution has formed with Mn²⁺-doped LiZnPO4 and Zn²⁺-doped Li Mn PO4.Besides,the densification temperature of it has decreased.The peak dielectric property has been obtained when x=0.3 and sintered at 800℃,that areεr=5.83,Q×f=71007 GHz,τf=-82.84 ppm/°C,and relative density=97.33%.Thirdly,a small amount of Mn²⁺has been used to substitute the Zn²⁺of LiZnPO4 ceramic.The sintering property of the ceramic has been modified,and the relative density and dielectric property have been improved.The peak dielectric property has been obtained when x=0.04 and sintered at825℃,that are relative density=97.8%,εr=5.57,Q×f=77900 GHz,andτf=-80.54 ppm/°C.Fourthly,theτf of Li Zn0.96Ni0.04PO4 and Li Zn0.96Mn0.04PO4 ceramics has been modified with the addition of Ti O2,and Ti O2 can co-exist with the main phase.The addition of Ti O2 enhanced the stiffness and elasticity of the ceramic,and the densification temperature andεr have increased.Besides,the Q×f of it has decreased,and a near zeroτf has obtained.When x=0.28 and sintered at 900°C,the dielectric property and relative density of 0.72Li Zn0.96Ni0.04PO4+0.28Ti O2 ceramic areτf=-3.66 ppm/°C,Q×f=34800GHz,εr=7.01,relative density=95.5%,and that of 0.72Li Zn0.96Mn0.04PO4+0.28Ti O2ceramic areτf=-2.16 ppm/°C,Q×f=29077 GHz,εr=7.04,relative density=95.1%.To realize the matching co-firing of 0.72Li Zn0.96Ni0.04PO4+0.28Ti O2 ceramic and0.2Ti O2+0.8Zn Ti O3 ceramic,the sintering property of these two ceramics has been modified by the addition of B2O3,and B2O3 can co-exist with the main phase.The sintering shrinkage and stress distribution characteristics of the heterogeneous model with the 0.72Li Zn0.96Ni0.04PO4+0.28Ti O2+xwt%B2O3 and 0.2Ti O2+0.8Zn Ti O3+xwt%B2O3ceramics have been researched using the finite element simulation,and the model with1.25wt%B2O3 has best matching co-firing performance.A common mode filter has been designed based on such ceramics and the matching co-firing technology of heterogeneous ceramic.It has high working frequency（>8 GHz）,simple geometry structure,wide suppression frequency,low insertion loss（<1.5 d B）,and the working frequency is easy to modify.Besides,such filter has been prepared through the low temperature co-fired ceramic technology.After sintering,the common mode filter has a compact heterogeneous interface and acceptable chemical compatibility,and no cracking nor element diffusion happened.The measured electrical property of the filter is similar with the designed one.This dissertation focused on the research of ceramic,realization of heterogeneous ceramic co-firing,and the preparation of common mode filter.It meets the requirements for materials and devices in the field of microwave and millimeter wave communication.Besides,this work provides a new method for the hybrid integration of functional modules.