The Development Of Multilayer Chip Emi Filter

The multilayer chip EMI filter that based on the low temperature Co-fired ferrit(LTCF) is a new type part.It is used in the EMC(Electro Magnetic Compatibility) environment.The filter is minitype,frivolity and broadband.It is abroad used in communications,communication,automobiled and fig-wiring equipment.The design of multilayer chip EMI(Electro Magnetic Interference)filter that based on the sutra filter theory set up a equivalent electocircuit model,via HFSS electromagnetism emulator account.In the design base of chip inductance and chip capacitance,we achieve the goal that manufacture a new type EMI filter.We design and analyze the 3D(three dimensional) structural model of LTCF EMI filter by HFSS(High Frequency Structure Simulater).The project has passed expertise appraisal, achieved the demand and gained good performance expected before.The important results and innovations are as follows:1.The design of multilayer LTCF EMI filter.In the paper,we introduce a new, high-efficient design means.With the design means and HFSS simulation emulator, we accomplish the EMI chip research and manufacture.A series of valuable laws for design have been obtained.It can be seen that muti-layer structure is smaller area and higher electrical performance.2.We respectively designed 0.2μH 3D helical inductors and 20nF VIC(Vertically Interdigitated Capacitor),and all of then had high quality factor.The emphasis of problem is how to get the helical inductors interconnect structure in ANSOFT—HFSS. With the theory of analysis above,three importance parameters is extracted and analysed.3.Combining the actual technics process of LTCF manufacture,we designed a Butterworth filter,which was made of 13 Electrocircuit layers.It had a size of 5.8×3.2×2.0mmWith the design of HFSS simulation emulator and LTCF process,we can speedy and efficient accieve the aim of design EMI chip filter.The capability voltage 200VDc/1min,insulation 1000MΩ,restrain degree(requency) 17.9dB(10MHz); 24.4dB(20MHz);47.5dB(100MHz)45.3dB(10MHz).current 2A.The measure of filter restrain degree is agree with the goal of emulator account.Now the LTCF having been the key technology in integration passive element such as chip inductance,filter and transfactor.on the hand,based on the LTCF technology.many new type component is designed.All kinds of chip components are tally with the development direction that digital and SMT of equipment,especially virtual load syst.As a result,with the design of HFSS simulation emulator and LTCF process,we can speedy and efficient aecieve the aim of designed EMI filter.