Method of Manufacturing Multilayer Wiring Board

Abstract

A multilayer wiring board with a high degree of heat resistance, which is capable of low temperature fusion without the occurrence of resin flow, enables high precision, finely detailed conductive wiring. can be ideally applied to low volume high mix manufacturing configurations, and also has little impact on the environment is provided, together with a semiconductor device mounting board using such a multilayer wiring board, and a method of manufacturing such a multilayer wiring board. In the multilayer wiring board, grooves for forming a wiring circuit and via holes are formed in an insulating substrate formed from a thermoplastic resin composition comprising a polyarylketone resin with a crystalline melting peak temperature of at least 260° C. and an amorphous polyetherimide resin as the primary constituents, a metallic foil is embedded within the grooves so that the surface of the foil protrudes to the surface of the insulating substrate, and a conductive material formed by curing a conductive paste is used for filling the via holes.

1 . A method of manufacturing a multilayer wiring board comprising the steps of:
 positioning an impressing jig on one surface of an insulating substrate formed from a thermoplastic resin composition comprising a polyarylketone resin with a crystalline melting peak temperature of at least 260° C. and an amorphous polyetherimide resin as primary constituents, with a metallic foil disposed therebetween, and positioning an elastic film, which displays a lower modulus of elasticity than said insulating substrate at temperatures lower than a glass transition temperature of said insulating substrate, on another surface of said insulating substrate,   subsequently using said impressing jig for performing thermal molding at a temperature which is higher than a glass transition temperature of said elastic film but lower than a crystallization start temperature of said insulating substrate, and   subsequently peeling off said metallic foil, so that only sections of said metallic foil in positions corresponding with convex sections of said impressing jib are fused to said insulating substrate.   
   
   
       2 . The method of  claim 1  wherein the insulating substrate has a thickness of about 100 μm or less. 
   
   
       3 . The method of  claim 1  wherein the insulating substrate is formed from an amorphous film produced by molten mixing and rapid cooling of the thermoplastic resin composition. 
   
   
       4 . The method of  claim 1  wherein the thermoplastic resin composition further comprises an inorganic filler. 
   
   
       5 . The method of  claim 4  wherein the inorganic filler is about 15 to 35% by weight of the thermoplastic resin composition. 
   
   
       6 . The method of  claim 4  wherein the inorganic filler has an average particle diameter of about 15 μm or less and an aspect ratio of about 30 or greater. 
   
   
       7 . The method of  claim 4  wherein the thermoplastic resin composition is formed by mixing about 100 parts by weight of a composition comprising the polyarylketone resin and the amorphous polyetherimide resin with about 20 to 50 parts by weight of the inorganic filler. 
   
   
       8 . The method of  claim 7  wherein the composition comprising the polyarylketone resin and the amorphous polyetherimide resin is formed from about 25 to 70% by weight of the polyarylketone resin. 
   
   
       9 . The method of  claim 8  wherein the composition comprising the polyarylketone resin and the amorphous polyetherimide resin is formed from about 30 to 75% by weight of the amorphous polyetherimide resin. 
   
   
       10 . The method of  claim 1  wherein the polyarylketone resin is selected from the group consisting of: a polyetherketone resin, a polyetheretherketone resin and a polyetherketoneketone resin. 
   
   
       11 . The method of  claim 1  wherein the glass transition temperature of the insulating substrate, the glass transition temperature of the elastic film, and the crystallization start temperature of the insulating substrate are measured using differential scanning calorimetry (DSC). 
   
   
       12 . The method of  claim 1  wherein the elastic film is formed from a syndiotactic polystyrene. 
   
   
       13 . The method of  claim 1  wherein the thermal molding is performed at a temperature lower than the glass transition temperature of the insulating substrate. 
   
   
       14 . The method of  claim 1  wherein the thermal molding is performed at a pressure of 0.5 to 10 kg/cm 2 . 
   
   
       15 . The method of  claim 1  wherein the thickness of the metallic foil is less than the height difference of the texture of the impressing jig. 
   
   
       16 . The method of  claim 1 , further comprising forming a wiring substrate on said insulating substrate by forming via holes within the insulating substrate, filling the via holes with a conductive paste, and heating the conductive paste to form a conductive material. 
   
   
       17 . The method of  claim 16 , further comprising laminating a plurality of said wiring substrates together, bonding and crystallizing the insulating substrates of said wiring substrates by thermal fusion at a temperature higher than said crystallization start temperature. 
   
   
       18 . The method of  claim 17  wherein the thermal fusion is performed at a temperature of about 200 to 260° C. and a pressure of about 20 to 60 kg/cm 2 .