High frequency circuit chip and method of producing the same

Abstract

In the production of a high frequency circuit chip in which a wiring pattern is disposed on a substrate having a through-hole, a connecting electrode of the through-hole is formed by filling electrically conductive paste into a perforation and firing it, and the wiring pattern is formed by a lift-off method. Moreover, at least the surface of the substrate for the wiring pattern to be formed thereon is mirror-polished, and thereafter, the wiring pattern is formed on the mirror-polished surface by the lift-off method.

1 - 8 . (canceled)  
   
   
       9 : A high frequency circuit chip comprising: 
 a substrate containing as a major component a ceramic with a high dielectric constant;    a wiring pattern disposed on one main surface of the substrate;    a conductor layer disposed on substantially the entire other main surface of the substrate;    a through-hole provided in the substrate; and    a connecting electrode disposed in the through-hole for connecting the wiring pattern and the electric conductor layer; wherein    at least the one main surface of the substrate on which the wiring pattern is disposed and the connecting electrode disposed in the through-hole are mirror-polished before the wiring pattern is disposed thereon; and    the wiring pattern includes an adhesion layer disposed on the substrate, a major conductor layer disposed on the adhesion layer, a buffer layer disposed on the major conductor layer, and a wire bonding layer disposed on the buffer layer.    
   
   
       10  (canceled).  
   
   
       11 : A high frequency circuit chip comprising: 
 a substrate containing as a major component a ceramic with a high dielectric constant;    a wiring pattern provided on each of front and back main surfaces of the substrate by the lift-off method;    a through-hole provided in the substrate; and    a connecting electrode disposed in the through-hole for connecting the wiring patterns provided on the front and back surfaces of the substrate; wherein    the front and back surfaces of the substrate on which the wiring pattern is disposed and the connecting electrode disposed in the through-hole are mirror-polished before the wiring patterns are disposed thereon; and    each of the wiring patterns includes an adhesion layer disposed on the substrate, a major conductor layer disposed on the adhesion layer, a buffer layer disposed on the major conductor layer, and a wire bonding layer disposed on the buffer layer.    
   
   
       12 - 13 . (canceled)  
   
   
       14 : A high frequency circuit chip according to  claim 11 , wherein the substrate has a relative dielectric constant of at least about 10.  
   
   
       15 : A high frequency circuit chip according to  claim 9 , wherein the wiring pattern disposed on the one main surface of the substrate and the electric conductor layer provided on substantially the entire other main surface include at least one metal selected from the group consisting of Ag, Cu, and Al as a major component, and have a thickness of at least about 2 μm.  
   
   
       16 : A high frequency circuit chip according to  claim 11 , wherein the wiring patterns disposed on each of the front and back main surfaces of the substrate include at least one metal selected from the group consisting of Ag, Cu, and Al as a major component, and have a thickness of at least about 2 μm.  
   
   
       17 : A high frequency circuit chip according to  claim 11 , wherein the connecting electrode of the through-hole includes at least one metal selected from the group consisting of Ag, Cu, and Al as a major component.  
   
   
       18 : A high frequency circuit chip according to  claim 9 , further comprising at least one thin film resistor disposed on the one main surface of the substrate.  
   
   
       19 : A high frequency circuit chip according to  claim 18 , wherein the thin film resistor includes tantalum nitride.  
   
   
       20 : A high frequency circuit chip according to  claim 11 , further comprising at least one thin film resistor disposed on at least one of the front and back surfaces of the substrate.  
   
   
       21 : A high frequency circuit chip according to  claim 20 , wherein the thin film resistor includes tantalum nitride.