Research Of High-performance LTCC Material Applied For Millimeter-wave Frequencies And The Tape-casting Technics

With the increasing of application frequency in electronics field,there have more demanding electronic components.Electronic equipment is developing towards to high frequency,miniaturization,multi-function and high integration.Low-temperature Co-Fired ceramic（LTCC）technology,based on tape design,can not only meet the requirements of miniaturization,but also achieve multi-function characteristics,and in line with the development direction of electronic equipment.At present,LTCC technology has become one of the indispensable technologies in the electronic technology.The popularization of 5G communication promotes the development of LTCC technology.Researchers did a lot of research on materials with low cost,low sintering temperature,low dielectric constant,low loss and near zero frequency temperature coefficient.In this study,Li₂O-Mg O-Zn O-B₂O₃-Si O₂（LMZBS）ceramic materials were prepared and other ceramics was added.The production feasibility of the material was verified by Tape-casting Technics.The main contents are as follows.（1）The effects of the proportion and content of different components on the phase,microstructure and dielectric properties of LMZBS multiphase ceramics were studied.1).Different Mg O/B2O3 ratio mainly affects the phase of Mg₂B₂O₅and Mg₃B₂O₆.Excessive Mg O or B₂O₃will deteriorating the dielectric properties.2)Different Li₂O/Si O₂ratio mainly affects the Li₂Mg Si O₄phase.Excessive Li₂O or Si O₂will lead to the generation of Li Mg BO₃or Mg₂Si O₄in the sample,respectively,which will deteriorate the performance.3)As an additive,Zn O is added to LMZBS ceramics to decrease sintering temperature.Excess Zn O leads to excess Mg O and deteriorates ceramic properties.In summary,the optimal dielectric properties of LMZBS multiphase ceramic materials are:?_r=6.66,Q=1250（10GHz）.（2）The effect of second ceramic that is Mg₂Si O₄and Ti O₂content on the composite was studied.1)Mg₂Si O₄ceramic can improve the dielectric properties and decrease sintering temperature.The Mg₂Si O₄content between 10～20 wt%can be sintered densified at 900℃.the composite have the best performance which with 20 wt%Mg₂Si O₄.2)The addition of Ti O₂can adjust the frequency temperature coefficient.An additional 5 wt%Cu O can reduce the sintering temperature below 900℃.When the content of Ti O₂is 10wt%,the comprehensive performance of the material reaches the best,and the frequency temperature coefficient is nearly zero.（3）The Tape-casting Technics of Mg₂Si O₄/LMZBS composite ceramic powder was verified.When PVB is used as an adhesive,the hydroxyl content of PVB needs to be appropriate.The high hydroxyl content will increase the viscosity due to the cross-linking reaction.Low hydroxyl content results in low viscosity.In addition,Mg₂Si O₄/LMZBS composite were co-fired with Ag metal electrode,and there is no obvious diffusion or reaction between of them,the results show that the Ag metal and Mg₂Si O₄/LMZBS composite ceramic materials have good chemical compatibility.