Low-temperature Sintering Of M-type Barium Ferrite High Frequency Soft Magnetic Properties And Applied Research

The rapidly developing of electronic and information technology calls for the circle components and modules being miniaturized integrated and high frequency all of this has become the crucial standard of the evaluating the development of this industry. Low Temperature Co-firing Ceramic (LTCC) technology being one of the best candidates to obtain these requirements so naturedly the study of the materials used in LTCC technology is important even to the whole electronic industry. And the M-style barium ferrite having the large coercive force magnetic energy produce and uniaxial magnetocrystalline anisotropy is widly studied in many fields including permanent magnetic material wave absorption material and microwave and millimeter wave devices. So in this article our work is largely focus on the application of M-style barium ferrite in LTCC technology is studied.In the materials aspect the performance of Ba-ferrite in microwave is taken in consideration. The Co and Ti substituted ferrite is fabricated by sol-gel process the measurement shows that the substitution increase the soft magnetic performance of this material in high-frequency. And the study of how the doping amount sintering temperature and sintering agent BBSZ effect the magnetic characteristics of M-style Ba-ferrite is carried out which shows that the sintering agent will benefit the growth of grain bring down the sintering temperature and the doping of Co and Ti will increase the initial permeability of the Ba-ferrite and also improve the soft magnetic behavior in high frequency. We have fabricated the M-style Ba-ferrite with initial permeability being 14 cut-off frequency being 800MHz which can be applied in high frequency multilayer chips inductor.In the multilayer chips components aspect we have studied tape casting process and confirmed the feasibility of M-style Ba-ferrite applicated in LTCC technology. Utilizing HFSS we obtained the optimized parameters of the multilayer chips inductors and filters. Then the samples of these inductors and filters were fabricated using the LTCC production line in UESTC. The measurements show that the inductance of the inductor sample is 1μH a little lower than the simulation one which is thought to be caused by the difference of permeability between the ferrite and standard sample. On the other hand the filter sample with cut-off frequency being 400MHz out band rejection larger than 25dB in the frequency 2GHz reason of the higher cut-off frequency is thought to be the processing parameters in LTCC are hard to be controlled.