High-frequency core and inductance component using the same

Abstract

A high-frequency core is a molded body obtained by molding a mixture of a soft magnetic metallic glass powder and a binder in an amount of 10% or less in mass ratio. The powder has an alloy composition represented by (Fe 1-a Co a ) 100-x-y-z-q-r (M 1-p M′ p ) x T y B z C q Al r (0<a<0.50, 0<p<0.5, 2 atomic %<x<5 atomic %, 8 atomic %<y<12 atomic %, 12 atomic %<z<17 atomic %, 0.1 atomic %<q<1.0 atomic %, 0.2 atomic %<r<2.0 atomic % and 25<(x+y+z+q+r)<30, M being at least one selected from Zr, Nb, Ta, Hf, Mo, Ti, V, Cr, and W, M′ being at least one selected from Zn, Sn, and R (R being at least one element selected from rare earth metals including Y), T being at least one selected from Si and P). An inductance component is formed by the core and a winding.

1 . A high-frequency core comprising a molded body obtained by molding a mixture of a soft magnetic metallic glass powder and a binder in an amount of 10% or less in mass ratio with respect to the soft magnetic metallic glass powder, said soft magnetic metallic glass powder having an alloy composition represented by (Fe 1-a Co a ) 100-x-y-z-q-r (M 1- M′ p ) x T y B z C q Al r , where 0<a<0.50, 0<p<0.5, 2 atomic %<x<5 atomic %, 8 atomic %<y<12 atomic %, 12 atomic %<z<17 atomic %, 0.1 atomic %<q<1.0 atomic %, 0.2 atomic %<r<2.0 atomic % and 25<(x+y+z+q+r)<30, M being at least one element selected from the group consisting of Zr, Nb, Ta, Hf, Mo, Ti, V, Cr and W, M′ being at least one element selected from the group consisting of Zn, Sn and R, R being at least one rare earth metal element selected from the group consisting of a lanthanum series element and Y, T being at least one element selected from the group consisting of Si and P.  
   
   
       2 . The high frequency core according to  claim 1 , wherein the molded body has a powder filling rate of 50% or more, a magnetic flux density of 0.5 tesla or more when a magnetic field of 1.6×10 4  A/m is applied, and a specific resistance of 1×10 4  Ωcm or more.  
   
   
       3 . The high-frequency core according to  claim 1 , wherein the molded body is obtained by preparing the mixture of the soft magnetic metallic glass powder and the binder in an amount of 5% or less in mass ratio with respect to the soft magnetic metallic glass powder, and compression-molding the mixture using a die, the molded body having a powder filling rate of 70% or more, a magnetic flux density of 0.70 tesla or more when a magnetic field of 1.6×10 4  A/m is applied, and a specific resistance of 1 Ωcm or more.  
   
   
       4 . The high frequency core according to  claim 1 , wherein the molded body is obtained by preparing the mixture of the soft magnetic metallic glass powder and the binder in an amount of 3% or less in mass ratio with respect to the soft magnetic metallic glass powder, and compression-molding the mixture using a die under a temperature condition not lower than a softening point of the binder, the molded body having a powder filling rate of 80% or more, a magnetic flux density of 0.9 tesla or more when a magnetic field of 1.6×10 4  A/m is applied, and a specific resistance of 0.1 Ωcm or more.  
   
   
       5 . The high-frequency core according to  claim 1 , wherein the molded body is obtained by preparing the mixture of the soft magnetic metallic glass powder and the binder in an amount of 1% or less in mass ratio with respect to the soft magnetic metallic glass powder, and compression-molding the mixture at a temperature within a supercooled liquid temperature range of the soft magnetic metallic glass powder, the molded body having a powder filling rate of 90% or more, a magnetic flux density of 1.0 tesla or more when a magnetic field of 1.6×10 4  A/m is applied, and a specific resistance of 0.01 Ωcm or more.  
   
   
       6 . The high-frequency core according to  claim 1 , wherein the soft magnetic metallic glass powder is produced by water atomization or gas atomization and at least 50% of powder particles have a size not smaller than 10 μm.  
   
   
       7 . The high-frequency core according to  claim 1 , wherein a soft magnetic alloy powder having an average diameter smaller than that of the soft magnetic metallic glass powder and a low hardness is added in an amount of 5-50% in volume ratio.  
   
   
       8 . The high-frequency core according to  claim 1 , wherein the soft magnetic metallic glass powder has an aspect ratio (long axis/short axis) substantially within a range between 1 and 2.  
   
   
       9 . The high-frequency core according to  claim 1 , wherein the molded body is heat treated at a temperature not lower than a Curie point of the alloy powder after molding, SiO 2  being contained at least in a part of an intermediate material between powder particles of the alloy powder.  
   
   
       10 . An inductance component comprising the high-frequency core claimed in  claim 1  and at least one turn of winding wound around the core.  
   
   
       11 . The inductance component according to  claim 10 , wherein a gap is formed at a part of a magnetic path of the high-frequency core.  
   
   
       12 . The high frequency core according to  claim 1 , wherein the soft magnetic metallic glass powder has a maximum particle size of 45 μm or less in mesh size and an average diameter of 30 μm or less.  
   
   
       13 . The high frequency core according to  claim 12 , wherein a soft magnetic alloy powder having an average diameter smaller than that of the soft magnetic metallic glass powder and a low hardness is added in an amount of 5-50% in volume ratio.  
   
   
       14 . The high-frequency core according to  claim 12 , wherein the soft magnetic metallic glass powder has an aspect ratio (long axis/short axis) substantially within a range between 1 and 2.  
   
   
       15 . The high-frequency core according to  claim 12 , wherein the powder filling rate is 50% or more and a peak value of Q is 40 or more at 500 kHz or more.  
   
   
       16 . The high frequency core according to  claim 12 , wherein the soft magnetic metallic glass powder has a maximum powder particle size of 45 μm or less in mesh size and an average diameter of 20 μm or less and a peak value of Q of the high frequency core is 50 or more at 1 MHz or more.  
   
   
       17 . An inductance component comprising the high-frequency core claimed in  claim 12  and at least one turn of winding coil wound around the core.  
   
   
       18 . The inductance component according to  claim 17 , wherein the winding coil is embedded in a magnetic body and formed by press-molding into an integral structure.  
   
   
       19 . The inductance component according to  claim 17 , wherein the molded body forms at least one turn of winding coil, the winding coil being embedded in a magnetic body and formed by press-molding into an integral structure.  
   
   
       20 . The inductance component according to  claim 17 , wherein a heat treatment at a temperature not higher than 600° C. is performed.  
   
   
       21 . The high-frequency core according to  claim 1 , wherein Fe and/or Co is in an amount of not less than 70 atomic % and not greater than 75 atomic %; M is in an amount of not less than 2 atomic % and not greater than 5 atomic %; Si is in an amount of not less than 8 atomic % and not greater than 12 atomic %; and B is in an amount of not less than 12 atomic % and not greater than 12 atomic %.  
   
   
       22 . The high-frequency core according to  claim 1 , wherein the alloy has a composition selected from the group consisting of 
 Fe 72 Si 9 B 14.5 Nb 3 Al 1.0 C 0.5 ,    Fe 71  Si 9 B 14.5 Nb 4 Al 1.0 C 0.5 ,    Fe 70 Si 9 B 14.5 Nb 5 Al 1.0 C 0.5 ,    Fe 74 Si 8 B 13.5 Nb 3 Al 1.0 C 0.5 ,    Fe 72 Si 10 B 13.5 Nb 3 Al 1.0 C 0.5 ,    Fe 70 Si 12 B 13.5 Nb 3 Al 1.0 C 0.5 ,    Fe 75.5 Si 8.5 B 12 Nb 3 Al 1.0 C 0.5 ,    Fe 72 Si 8.5 B 15 Nb 3 Al 1.0 C 0.5 ,    Fe 70 Si 8.5 B 17 Nb 3 Al 1.0 C 0.5 ,    (Fe 0.9 Co 0.1 ) 73 Si 9 B 14.5 Nb 2 Al 1.0 C 0.5 ,    (Fe 0.7 Co 0.3 ) 73 Si 9 B 14.5 Nb 2 Al 1.0 C 0.5 ,    (Fe 0.5 Co 0.5 ) 73 Si 9 B 14.5 Nb 2 Al 1.0 C 0.5 ,    (Fe 0.7 Co 0.3 ) 73 Si 9 B 14.5 Ta 2 Al 1.0 C 0.5 ,    (Fe 0.7 Co 0.3 ) 73 Si 9 B 14.5 Mo 2 Al 1.0 C 0.5 ,    Fe 73 Si 8 B 14.5 Nb 2.0 Zn 1.0 Al 1.0 C 0.5 ,    Fe 73 Si 8 B 14.5 Nb 1.5 Zn 1.5 Al 1.0 C 0.5 ,    Fe 73.5 Si 8 B 14.5 Nb 2 Zn 0.5 Al 1.0 C 0.5 ,    Fe 71  Si 8 B 14.5 Nb 4.5 Zn 0.5 Al 1.0 C 0.5 ,    Fe 74 Si 8 B 14.5 Nb 1.5 (misch metal) 0.5 ,    Al 1.0 C 0.5 ,    (Fe 0.7 Co 0.3 ) 74 Si 8 B 14.5 Nb 1.5 Zn 0.6 Al 1.0 C 0.5 ,    (Fe 0.7 Co 0.3 ) 74 Si 8 B 14.5 Ta 1.6 Zn 0.5 Al 1.0 C 0.5 ,    (Fe 0.7 Co 0.3 ) 74 Si 8 B 14.5 Mo 1.5 Zn 0.5 Al 1.0 C 0.5 ,    Fe 71.5 Si 9 B 14.5 Nb 3 Al 1.0 C 1.0 ,    Fe 71.5 Si 9 B 14.5 Nb 3 Al 1.5 C 1.0 ,    Fe 71 Si 9 B 14.5 Nb 3 Al 2.0 C 1.0 ,    (Fe 0.8 Co 0.2 ) 73 Si 9 B 14.5 Nb 2 Al 1.0 C 0.5 ,    Fe 72 Si 9 B 14.5 Nb 3 Al 1.0 C 0.5 ,    Fe 71.3 Si 9 B 14.5 Nb 3 C 0.7 Al 1.5 ,    Fe 71.5 Si 9 B 14.5 Nb 3 C 0.5 Al 1.5 ,    Fe 72.0 Si 9 B 14.5 Nb 3 C 0.5 Al 1.0 , and    Fe 73.2 Si 9 B 14.5 Nb 3 C 0.1 Al 0.2 .