Connecting member of a circuit substrate and method of manufacturing multilayer circuit substrates by using the same

Abstract

A connecting member of circuit substrates includes an organic porous base material provided with tackfree films on both sides, through-holes disposed at requested places which are filled with conductive resin compound up to the surface of the tackfree films. This structure enables inner-via-hole connection and can therefore attain a connecting member of circuit substrates and an electrical connector of high reliability and high quality. By using a connecting member of circuit substrates including the organic porous base material provided with tackfree films on both sides and through-holes disposed at requested places which are filled with conductive resin compound up to the surface of the tackfree films, it is possible to form a high-multilayer substrate easily from double sided boards or four-layer substrates which can be manufactured rather stably. In addition to that, since the conductive paste is filled up to the surface of the tackfree films, the conductive paste sticks out from the surface of the organic porous base material when the tackfree films are separated. As a result, the filled amount of the conductive substance increases after the lamination, and thus, the connection resistance is reduced considerably.

What is claimed is:  
     
         1 . A connecting member of a circuit substrate comprising an organic porous base material provided with tackfree films on both sides, wherein said connecting member of circuit substrates has through-holes, and said through-holes are filled with conductive resin compound up to the surface of said tackfree films.  
     
     
         2 . The connecting member of circuit substrates as in    claim 1   , wherein said organic porous base material is a composite material which comprises a nonwoven heat-resisting synthetic fiber fabric impregnated with an uncured thermosetting resin.  
     
     
         3 . The connecting member of a circuit substrate as in    claim 2   , wherein said nonwoven heat-resisting synthetic fiber fabrics comprise aramid resin, while said uncured thermosetting resin is epoxy resin.  
     
     
         4 . The connecting member of a circuit substrate as in    claim 2   , wherein said nonwoven heat-resisting synthetic fiber fabric comprises paper, and said uncured thermosetting resin is selected from the group consisting of phenol resin and epoxy resin.  
     
     
         5 . The connecting member of circuit substrates as in    claim 1   , wherein a conductive substance contained in said conductive resin compound is at least one metallic powder selected from the group consisting of silver, nickel, copper, silver alloy, nickel alloy, and copper alloy.  
     
     
         6 . The connecting member of circuit substrates as in    claim 2   , wherein a resin component contained in said conductive resin compound is the same as the thermosetting resin in said organic porous base material.  
     
     
         7 . The connecting member of circuit substrates as in    claim 1   , wherein said through-holes are formed by laser irradiation.  
     
     
         8 . The connecting member of a circuit substrate as in    claim 1   , wherein said through-holes filled with the conductive resin compound have a diameter of 50 μm to 1 mm.  
     
     
         9 . The connecting member of a circuit substrate as in    claim 1   , wherein said through-holes filled with the conductive resin compound have a pitch of 50 μm or more.  
     
     
         10 . The connecting member of circuit substrates as in    claim 1   , wherein said through-holes filled with the conductive resin compound have an electrical resistance of 0.05 to 5.0 mΩ.  
     
     
         11 . The connecting member of circuit substrates as in    claim 1   , wherein said porous base material has a porosity of from 2 to 35%.  
     
     
         12 . A method of manufacturing a multilayer circuit substrate comprising the steps of: 
 (a) providing a multilayer circuit substrate having at least two layers of circuit patterns, a circuit substrate having at least one layer of circuit pattern, and said connecting member for circuit substrates consisting of an organic porous base material provided with tackfree films on both sides which is disposed with through-holes filled with conductive resin compound up to the surface of said tackfree films;    (b) separating said tackfree films from said connecting member of circuit substrates;    (c) positioning said connecting member of circuit substrates between the multilayer circuit substrate and the circuit substrate; and    (d) heating and pressurizing.    
     
     
         13 . The method of manufacturing a multilayer circuit substrate as in    claim 12   , wherein said organic porous base material is a composite material which comprises a nonwoven heat- resisting synthetic fiber fabric impregnated with uncured thermosetting resin.  
     
     
         14 . The method of manufacturing a multilayer circuit substrate as in    claim 13   , wherein said nonwoven heat-resisting synthetic fiber fabric comprises aramid resin, and said uncured thermosetting resin is epoxy resin.  
     
     
         15 . The method of manufacturing a multilayer circuit substrate in    claim 12   , wherein said nonwoven heat-resisting synthetic fiber fabric comprises paper, and said uncured thermosetting resin is selected from the group consisting of phenol resin and epoxy resin.  
     
     
         16 . The method of manufacturing a multilayer circuit substrate as in    claim 12   , wherein a conductive substance contained in said conductive resin compound is at least one metallic powder selected from the group consisting of silver, nickel, copper, silver alloy, nickel alloy, and copper alloy.  
     
     
         17 . The method of manufacturing a multilayer circuit substrate as in    claim 12   , wherein a resin component contained in said conductive resin compound is the same as the thermosetting resin in said organic porous base material.  
     
     
         18 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 12   , wherein said multilayer circuit substrate having at least two layers of circuit patterns and said circuit substrate having at least one layer of circuit pattern comprise glass-epoxy substrates having copper foil wirings and copper-plated through-holes.  
     
     
         19 . The method of manufacturing a multilayer circuit substrate as in    claim 12   , wherein said multilayer circuit substrate having at least two layers of circuit patterns and said circuit substrate having at least one layer of circuit pattern comprise aramid nonwoven fabrics and thermosetting epoxy resin.  
     
     
         20 . The method of manufacturing a multilayer circuit substrate as in    claim 12   , wherein said through-holes are formed by laser irradiation.  
     
     
         21 . The method of manufacturing a multilayer circuit substrate as in    claim 12   , wherein said through-holes filled with the conductive resin compound have a diameter of 50 μm to 1 mm.  
     
     
         22 . The method of manufacturing a multilayer circuit substrate by using the connecting member of a circuit substrate as in    claim 12   , wherein said through-holes filled with the conductive resin compound have a pitch of 50 μm or more.  
     
     
         23 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 12   , wherein said through-holes filled with the conductive resin compound have an electrical resistance of 0.05 to 5.0 mΩ.  
     
     
         24 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 12   , wherein said porous base material has a porosity of from 2 to 35%.  
     
     
         25 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 12   , wherein the heating is carried out at a temperature of from 170 to 260° C.  
     
     
         26 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 12   , wherein the pressurization is carried out at a pressure of from 20 to 80 kg/cm 2 .  
     
     
         27 . A method of manufacturing a multilayer circuit substrate comprising the steps of: 
 (a) providing a multilayer circuit substrate having at least two layers of circuit patterns and two pieces of said connecting member of a circuit substrate consisting of an organic porous base material provided with tackfree films on both sides which is disposed with through-holes filled with conductive resin compound up to the surface of said tackfree films;    (b) separating said tackfree films from said connecting members of circuit substrates;    (c) positioning said multilayer circuit substrate between the two connecting members of circuit substrates;    (d) applying a metal foil on both sides; and    (e) heating and pressurizing, and forming circuit patterns on said metal foils.    
     
     
         28 . The method of manufacturing a multilayer circuit substrate as in    claim 27   , wherein said organic porous base material is a composite material which comprises a nonwoven heat-resisting synthetic fiber fabric impregnated with an uncured thermosetting resin.  
     
     
         29 . The method of manufacturing a multilayer circuit substrate by using the connecting member of a circuit substrate as in    claim 28   , wherein said nonwoven heat-resisting synthetic fiber fabrics comprise aramid resin, and said uncured thermosetting resin is epoxy resin.  
     
     
         30 . The method of manufacturing a multilayer circuit substrate as in    claim 28   , wherein said nonwoven heat-resisting synthetic fiber fabric comprises paper, and said uncured thermosetting resin is selected from the group consisting of phenol resin and epoxy resin.  
     
     
         31 . The method of manufacturing a multilayer circuit substrate as in    claim 27   , wherein a conductive substance contained in said conductive resin compound is at least one metallic powder selected from the group consisting of silver, nickel, copper, silver alloy, nickel alloy, and copper alloy.  
     
     
         32 . The method of manufacturing a multilayer circuit substrate as in    claim 27   , wherein a resin component contained in said conductive resin compound is the same as the thermosetting resin in said organic porous base material.  
     
     
         33 . The method of manufacturing a multilayer circuit substrate as in    claim 27   , wherein said multilayer circuit substrate having at least two layers of circuit patterns comprises glass-epoxy multilayer circuit substrates having copper foil wirings and copper-plated through-holes.  
     
     
         34 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 27   , wherein said multilayer circuit substrate having at least two layers of circuit patterns comprises an aramid nonwoven fabric and a thermosetting epoxy resin.  
     
     
         35 . The method of manufacturing a multilayer circuit substrate as in    claim 27   , wherein said through-holes are formed by laser irradiation.  
     
     
         36 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 27   , wherein said through-holes filled with the conductive resin compound have a diameter of 50 μm to 1 mm.  
     
     
         37 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 27   , wherein said through-holes filled with the conductive resin compound have a pitch of 50 μg m or more.  
     
     
         38 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 27   , wherein said through-holes filled with the conductive resin compound have an electrical resistance of 0.05 to 5.0 mΩ.  
     
     
         39 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 27   , wherein said porous base material has a porosity of from 2 to 35%.  
     
     
         40 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 27   , wherein the heating is carried out at a temperature of from 170 to 260°C.  
     
     
         41 . The method of manufacturing a multilayer circuit substrate by using the connecting member of circuit substrates as in    claim 27   , wherein the pressurization is carried out at a pressure of from 20 to 80 kg/cm 2 .