Ex parte HASEGAWA et al. - Page 2

          Appeal No. 1997-2046                                       Page 2           
          Application No. 08/059,350                                                  

          inductor for such a choke coil achieves miniaturization, it                 
          suffers several drawbacks.  Because the inductor uses an                    
          amorphous alloy ribbon                                                      
          having a high permeability as a ferromagnetic ribbon, the                   
          inadequate magnetic characteristics of the ribbon produce poor              
          DC superposition characteristics.  In turn, the poor DC                     
          superposition characteristics reduce inductance, making                     
          control difficult and lowering the efficiency of a DC-to-DC                 
          converter to which the planar inductor is applied.  Even if                 
          the DC superposition characteristics can be improved, a high-               
          frequency loss of the ferromagnetic ribbon limits the                       
          efficiency of the applied DC-to-DC converter.                               

               In practice, the planar inductor is coated with a mold                 
          resin.  If the amorphous alloy ribbon has a positive                        
          saturation magnetostriction, when the surface of the planar                 
          inductor is coated with a liquid mold resin and the resin is                
          hardened, contraction of the mold resin applies a compressive               
          stress to the ferromagnetic ribbon.  An inverse                             
          magnetostrictive effect decreases effective permeability, thus              
          reducing an inductance.                                                     

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