, 50. 1-10) mm-wave power handling,. bulk, (,,, ),. microelectronics device device digital GHz. transformer coil. core loss MnZn, NiZn 10 k m MnZn. GHz Z. MHz~GHz,, LC. Co 2Z 1300 900.. 1 GHz (natural resonance frequency), 1 GHz GHz.,,. 38
.,,. 2.1. NiZn (MgAl 2O 4) Fig. 1., 4 8, 8.3~8.7, NiZn Ni Zn 8.311~8.418, Zn. M 2+ O Fe 2O 3 MFe 2O 4 unit cell 8 MFe 2O 4. (fcc), unit cell 24 (5 B Fe 3+ M 2+ ) 32. 8 A (tetrahedral site) 16 B (octahedral site). A 4 4, B 6 8 M 2+ A (normal spinel), B (inversed spinel). NiZn Zn Ni (mixed ferrite). 11,12)., (Table 1),,., A-B., J AA, J BB J AB (negative),. AB A B A B., A B net moment. 11),,,. Table 1. Classification of Cations for Spinel Ferrite Solid Solutions Fig. 1. Unit cell structure of spinel ferrites (A : tetrahedral site, B : octahedral site). 39
., peak.,, Snoek., NiZn Ni ( Zn ). Fe 2O 3 NiZn, Fe 2O 3., NiZn (Ni yzn 1 yo) 1 w(fe 2O 3) 1 w y=0.3~0.4, w 0. NiZn. Fe 2O 3., Fe 2O 3. Fe 2 Fe 3 hopping.. Fe 2O 3 Fe Fe 3, Fe Fe 2 Fe 3 Fe 2 Fe 3.,,,.,.,. (Hysteresis Loop), (magnetic core materials). Power transformer magnetic field, magnetic field,,. i. (, I s :, K :, :, : ) i K 0,. (Fig. 2) ( = j ), H( ) B( ), H 90 B, / Fig. 2. Frequency dependence of permeability of soft ferrite materials. 40
... 12-15),,. hysteresis loop( )...,.,,.. (Snoek s limit),. NiZn. 10 MHz LC., 10 MHz.,, EMI. 13-17) NiZn CuZn MnZn (50 MHz )., NiZn 20 GHz (Table 2). Digital,. shield, monolith,.., NiCuZn. NiZn Table 2. Properties of NiZn Ferrites for Applications 41
Cu NiCuZn., Ag 960.5, Ag 950.. 2.2. (Hexagonal ferrite) ( -Fe 2O 3) 2 hexagonal.. a, b c Snoek s limit., GHz. c c Snoek s limit, MHz GHz. Fe, c a-b. Fe Ba( Sr, Pb, Ca), 2 (Ni, Mg, Co, Fe, Zn, Cu) (BaO-MeO-Fe 2O 3), BaFe 12O 19 (M)-Me 2Fe 4O 8(S) BaFe 12O 19(M)- Me 2BaFe 12O 22(Y) join. 14,19), S-block(Me 6O 8, Me Fe 3+ Co 2+ ), R-block(BaMe 6O 11), T-block(Ba 2Me 8O 14) M(BaFe 12O 19), W(MS/BaMe 2Fe 16O 27), X(M 2S /Ba 2Me 2Fe 28O 46), Y(Ba 2Me 2Fe 12O 22), U(M 2Y/ Ba 4 Me 2Fe 36O 60), Z(M 2Y 2/Ba 6Me 4Fe 48O 82) (Fig. 3,4). M BaFe 12O 19(BaM) W BaCo 2 Fe 16O 27 (Co 2W) c, Y Co 2Y(Ba 2Co 2Fe 12O 22) Z Co 2Z(Ba 3 Co 2Fe 24O 41) c (basal plane). Co 2Y Co 2Z.,. 300 MHz Z-type (Co 2Z) (3.7 GHz). Fig. 3. Phase diagram of hexagonal ferrites (M, W, Y, and Z / S : spinel). Fig. 4. Schematic diagram for crystal structure of M-type hexagonal ferrite (BaFe12O19). 42
Co 2Z ( 1250~1300 ),, 10 (300~700 MHz), Q-factor,., Ag 950. Co 2Y,,., Snoek s limit Co 2Z, Co 2Y, Ni 2Y mm. 14) 2.3. Garnet Garnet R 3Fe 5O 12 (R : Y, Gd) cubic system, Y 3 12, Fe 3 8 4 (Fig. 5). (sublattice point).,,, 0.1~500 GHz (eddy current loss) 10 7 m (ferromagnetic materials). microwave mm-wave. Fig. 5. Schematic diagram for crystal structure of YIG ferrite. 3.1. low noise amplifier, voltage-controlled oscillators, impedance matching networks inductive components., 1980 (Fig. 6).,, (core),,, LC filter, (MHD). (Surface Mount Technology) bulk Chip. 43
Fig. 6. Schematic diagram for multilayered chip ferrite and basic circuit for application. core magnetic flux., NiZn.., (magnetostriction) PZT 3 2, (magnetoelectric susceptibility).,., (BaTiO 3, Pb(Zr,Ti)O 3, Pb(Mg,Nb)O 3, PbTiO 3, (Sr, Ba) Nb 2O 5 ) (NiFe 2O 4, CoFe 2O 4, Y 3Fe 5O 12, Terfenol-D, metglass ) strain,,..,,.,.,, 3 (composite),.,., NiFe 2O 4/Pb(Zr,Ti)O 3 115 mv/cm Oe, 400 mv/cm Oe.,. power. power SMPS (switched-mode power supply), power signal, power. power 44
,. Power inductor(fig. 7) RF (Matching), Decoupling. 1 10~20 Pager, CLP, LAN. (eddy current), MnZn NiZn. 18,19), power, 80~100 140, MnZn Fe 2+. MnZn Fe 2+ (140 ). Fig. 7. Samples of chip inductor ; winding type (a, b) and multilayered type (c).[source for (b) : Murata Manufacturing Co. Ltd.].,, power circuit. 3.2. 100 GHz. skin-effect penetration. (domain wall),., defect, anisotropy field, (, Fe 2+ Fe 3+ hopping ). circulator, isolator, phase shifter, antenna circulator, mobile phone. (non-resonant absorption)..,, (Table 3). 0.1~500 GHz (eddy current loss) 10 7 m (ferromagnetic materials). ferrite microwave millimeter. Garnet,,,. (ferromagnetic resonance/fmr linewidth, H) 45
Table 3. Microwave Ferrites for Applications Table 4. Applications of NiZn Ferrite Materials Fig. 8. Schematic diagram for component structure of stripline Y-junction circulator., (spin-wave resonance linewidth, H k). Garnet 0.3~1.9 kg MHz~9 GHz. Fig. 8 circulator (permanent magnet) ferrite-loaded junction bias. 3.3. Electromagnetic Interference (EMI) Suppressor,,, IC (Table 4)., RFID (13.56 MHz) NiZn 100~300 m. NiZn, elastomer, m (100 MHz~1 GHz). film, SiP PCB (Fig. 9). 19-21) (complex permeability) Snoek, ( ). DC-DC convertor power inductor., core loss. PC,, EMI.,. (EMI). EMI suppressor. EMI suppressor 46
.,, EMI suppressor., Co 2Z Zn 2Y (10~30 ) Ni (2~3 ). Fig. 9. Microstructures and complex permeability(imaginary part, ") of composite-type noise suppression sheet and plated ferrite film.,, /, core-shell,. EMI suppressor,,,, clock. NiZn, 20~200 MHz. suppressor resistor,.,, resistor. EMI suppressor, ( )., 3.4. Near-Field Communication (NFC) 19) NiZn 13.56 MHz RFID. RFID. Fig. 10 RFID NiZn, 13.56 MHz ( ) ( ). (NFC). NFC. RFID/NFC Reader Transponder(Tag). LF(125 khz) HF(13.56 MHz) RFID (Eddy Current), Reader Transponder(Tag). 47
Fig. 10. Performance of permeability (a) and schematic diagram (b) of sintered flexible ferrite sheet (manufactured by Toda Kogyo Co. Ltd.).. 13.56 MHz NFC shield case,,. NFC/RFID. ( ). RFID.,. NiCuZn, 50~120 m. NFC/RFID Ferrite Sheet EMC TDK Maruwa. 13.56 MHz RFID Magnet Sheet TDK Maruwa EMI. NFC, NFC, flaky powder. NFC. 1930,., 10.,. NFC RFID,. 48
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