Composite, prepreg, laminated plate clad with metal foil, material for connecting circuit board, and multilayer printed wiring board and method for manufacture thereof

Abstract

It is an object of the invention to provide a composite with sufficiently reliable bonding and adequately minimized generation of fluff from flaking resin dust and fibers. This object is achieved by the composite ( 100 ) of the invention that comprises a fiber sheet ( 101 ) impregnated with a resin composition ( 102 ), wherein the 20° C. storage elastic modulus of the cured resin composition ( 102 ) is 100-2000 MPa. The composite ( 100 ) optionally contains perforations ( 103 ).

1 . A composite comprising a resin composition and a fiber sheet disposed in the resin composition,
 wherein the resin composition has a cured storage elastic modulus of 100-2000 MPa at 20° C.   
   
   
       2 . A composite according to  claim 1 , wherein the resin composition contains a viscoelastic resin. 
   
   
       3 . A composite according to  claim 1  or  2 , wherein the resin composition contains an acrylic polymer with a weight-average molecular weight of 30,000 or greater, and the acrylic polymer contains 2-20 wt % glycidyl acrylate as a polymerizing component and has an epoxy value of 2-36. 
   
   
       4 . A composite according to any one of  claims 1  to  3 , wherein the fiber sheet is a glass cloth with a thickness of 10-200 μm. 
   
   
       5 . A composite according to any one of  claims 1  to  4 , wherein the total thickness is no greater than 200 μm. 
   
   
       6 . A composite according to any one of  claims 1  to  5 , wherein the total thickness is no greater than 100 μm. 
   
   
       7 . A composite according to any one of  claims 1  to  6 , which possesses a perforation. 
   
   
       8 . A prepreg obtained by semi-curing of the resin composition in a composite according to any one of  claims 1  to  6 . 
   
   
       9 . A prepreg according to  claim 8 , which possesses a perforation. 
   
   
       10 . A metal foil-clad laminate obtained by heating and pressing a composite according to  claim 7  wherein the perforation has been filled with an electric conductor and a metal foil is situated on at least one side of the composite. 
   
   
       11 . A metal foil-clad laminate obtained by heating and pressing a prepreg according to  claim 9  wherein the perforation has been filled with an electric conductor and a metal foil is situated on at least one side of the prepreg. 
   
   
       12 . A circuit board connection material having a perforation formed at prescribed location of a prepreg according to  claim 8  bearing a releasable film on both sides thereof, and having a conductive resin composition filling the perforation up to the surface of the releasable film. 
   
   
       13 . A circuit board connection material having perforation formed at prescribed location of a prepreg according to  claim 8  bearing a releasable film on both sides thereof and having a conductive resin composition filling the perforation up to the surface of the releasable film, wherein the conductive resin composition protrudes from the surface of the prepreg when the releasable film is subsequently peeled off. 
   
   
       14 . A process for production of a multilayer printed circuit board, wherein a circuit board connection material according to  claim 13  is situated between a circuit board having at least a two-layer conductor pattern and a circuit board having at least a one-layer conductor pattern, and the stack is heated and pressed. 
   
   
       15 . A process for production of a multilayer printed circuit board wherein a circuit board connection material according to  claim 13  is placed on both sides of a circuit board having at least a two-layer conductor pattern, a metal foil is further placed on the outer sides of the circuit board connection material, the stack is heated and pressed, and the metal foil is worked to form a conductor pattern. 
   
   
       16 . A multilayer printed circuit board which is obtained by forming a multilayer board by alternate lamination of an insulating sheet obtained by forming first perforation on a prepreg according to  claim 8  or a prepreg laminate comprising a plurality of laminated prepregs according to  claim 8  and filling or coating the first perforation with a conductive paste and an inner layer printed circuit board having a conductor pattern formed on its surface, forming a laminated sheet by lamination of a copper foil on both sides of the multilayer board, forming second perforation running through both sides of the laminated sheet, forming a conductive layer on the walls of the perforation, and forming an outer layer conductor pattern on one or both sides of the laminated sheet. 
   
   
       17 . A process for production of a multilayer printed circuit board which comprises
 a step of bonding films onto both sides of a prepreg according to  claim 8  or a prepreg laminate comprising a plurality of the prepregs according to  claim 8  and then forming first perforation for communication between the surfaces of both films,   a step of filling or coating the first perforation with a conductive paste and then peeling the films from the prepreg or prepreg laminate to form an insulating sheet,   a step of bonding copper foils to both sides of the insulating sheet and then etching portions of the copper foils for removal to form an inner layer conductor pattern, in order to obtain an inner layer printed circuit board,   a step of alternately laminating the insulating sheet and the inner layer printed circuit board to form a multilayer board and laminating copper foils onto both sides of the multilayer board to form a laminated sheet, and subsequently or simultaneously compressing the laminated sheet to a compressibility ratio of 0-10% in the direction of lamination to form a copper-clad insulating substrate, and   a step of forming second perforation in the copper-clad insulating substrate, and then forming conductive layers by copper plating on the surface including the second perforation and etching portions of the conductive layers and the copper foils on the copper-clad insulating substrate surface for removal to form an outer layer conductor pattern.   
   
   
       18 . A process for production of a multilayer printed circuit board which comprises
 a step of bonding first films onto both sides of a prepreg according to  claim 8  or a prepreg laminate comprising a plurality of the prepregs according to  claim 8  and then forming first perforation for communication between the surfaces of the first films,   a step of filling or coating the first perforation with a conductive paste and then peeling off the first films from the prepreg or prepreg laminate to form an insulating sheet,   a step of bonding second films to both sides of the insulating sheet having an inner layer conductor pattern formed on the surface thereof and then forming second perforation for communication between the surfaces of the second films,   a step of filling or coating the second perforation with a conductive paste and then peeling off the second films to form an inner layer printed circuit board,   a step of alternately laminating the insulating sheet and the inner layer printed circuit board to form a multilayer board, laminating copper foils onto both sides of the multilayer board to form a laminated sheet, and subsequently or simultaneously compressing the laminated sheet to a compressibility ratio of 0-10% in the direction of lamination to form a copper-clad insulating substrate, and   a step of forming third perforation in the copper-clad insulating substrate, and then forming conductive layers by copper plating on the surface including the third perforation and etching portions of the conductive layers and the copper foils on the copper-clad insulating substrate surface for removal to form an outer layer conductor pattern.   
   
   
       19 . A process for production of a multilayer printed circuit board which comprises
 a step of bonding first films onto both sides of a prepreg according to  claim 8  or a prepreg laminate comprising a plurality of the prepregs according to  claim 8  and then forming first perforation for communication between the surfaces of the first films,   a step of filling or coating the first perforation with a conductive paste and then peeling off the first films from the prepreg or prepreg laminate to form an inner layer insulating sheet,   a step of attaching copper foils to both sides of the inner layer insulating sheet and then etching portions of the copper foil on one of the copper foil sides for removal, to form a conductor pattern in order to obtain an outer layer printed circuit board,   a step of laminating the inner layer insulating sheet and two outer layer printed circuit boards in such a manner that the outer layer printed circuit boards sandwich the inner layer insulating sheet and that the conductor pattern is on the back, to form a laminated sheet, and subsequently or simultaneously compressing the laminated sheet to a compressibility ratio of 0-10% in the direction of lamination to form a copper-clad insulating substrate, and   a step of forming second perforation in the copper-clad insulating substrate and then forming a conductive layer by copper plating on the surface including the second perforation and etching a portion of the conductive layer and the copper foil on the copper-clad insulating substrate surface for removal to form an outer layer conductor pattern.