Method of manufacture of multilayer circuit board

Claim 1

A method of manufacturing a multilayer circuit board for mounting ICs comprising the steps of: forming required circuit wiring patterns on the inner conductive circuit layers except outer conductive circuit layers; boring holes for conduction in inner and outer conductive circuit layers at portions where these conductive layers are to be connected together, the holes for conduction having diameters that gradually increase; laminating the inner and outer conductive circuit layers one upon another via insulating base members and joining them together; boring stepped holes by removing the insulating base members from portions where the conductive layers are to be electrically connected to each other in a manner that the conductive layers are exposed stepwisely; patterning said outer conductive circuit layers to form a required circuit wiring after an interlayer conductive members has been formed in said stepped holes; and forming electrically conductive bump members for connection to IC pads on the interlayer conductive members so as to outwardly protrude from the circuit board.

Claim 2

A method of manufacturing a multilayer circuit board for mounting ICs comprising the steps of: forming required circuit wiring patterns on the inner conductive circuit layers except outer conductive circuit layers; boring holes for conduction in inner and outer conductive circuit layers at portions where these conductive layers are to be connected together, the holes for conduction having diameters that gradually increase; laminating the inner and outer conductive circuit layers one upon another via insulating base members and joining them together; boring stepped holes by removing the insulating base members from portions where the conductive layers are to be electrically connected to each other in a manner that the conductive layers are exposed stepwisely; patterning said outer conductive circuit layers to form a required circuit wiring after an interlayer conductive members has been formed in said stepped holes; and forming electrically conductive bump members for connection to IC pads on the interlayer conductive members so as to outwardly protrude from the circuit board.

Claim 10

A method of manufacturing a multilayer circuit board for mounting ICs comprising the steps of: forming required circuit wiring patterns on the inner conductive circuit layers except outer conductive circuit layers; boring holes for conduction in said inner and outer conductive circuit layers at portions where these conductive layers are to be connected together, the holes for conduction having diameters that gradually increase; laminating the inner and outer conductive circuit layers one upon another via insulating base members and joining them together; boring stepped holes by removing the insulating base members from portions where the conductive layers are to be electrically connected to each other in a manner that the conductive layers are exposed stepwisely; effecting solder plating on said stepped holes in order to electrically connect said conductive layers to each other, parts of the solder-plated members outwardly protruding from the circuit board thereby to form electrically conductive bump members for connection to IC pads; and subjecting said outer conductive circuit layers to predetermined circuit wiring patterning.

Claim 11

A method of manufacturing a multilayer circuit board for mounting ICs comprising the steps of: forming required circuit wiring patterns on the inner conductive circuit layers except outer conductive circuit layers; boring holes for conduction in said inner and outer conductive circuit layers at portions where these conductive layers are to be connected together, the holes for conduction having diameters that gradually increase; laminating the inner and outer conductive circuit layers one upon another via insulating base members and joining them together; boring stepped holes by removing the insulating base members from portions where the conductive layers are to be electrically connected to each other in a manner that the conductive layers are exposed stepwisely; effecting solder plating on said stepped holes in order to electrically connect said conductive layers to each other, parts of the solder-plated members outwardly protruding from the circuit board thereby to form electrically conductive bump members for connection to IC pads; and subjecting said outer conductive circuit layers to predetermined circuit wiring patterning.

Claim 14

A method of manufacturing a multilayer circuit board for mounting ICs comprising the steps of: forming required circuit wiring patterns on the inner conductive circuit layers except outer conductive circuit layers; removing the conductive circuit layers from portions where electric connection is to be made to a particular conductive circuit layer among said inner and outer conductive circuit layers in a size that does not affect the electric conduction; laminating said inner and outer conductive circuit layers one upon another via insulating base members and joining them together; removing said insulating base members from the portions where the electric connection is to be made thereby to form holes for conduction in which said particular conductive circuit layer is exposed; forming an electrically conductive members in said hole followed by a predetermined circuit wiring patterning treatment for said outer conductive circuit layer; and forming electrically conductive bump members for connection to IC pads on said interlayer conductive members in a manner to protrude outwardly from the circuit board.

Claim 15

A method of manufacturing a multilayer circuit board for mounting ICs comprising the steps of: forming required circuit wiring patterns on the inner conductive circuit layers except outer conductive circuit layers; removing the conductive circuit layers from portions where electric connection is to be made to a particular conductive circuit layer among said inner and outer conductive circuit layers in a size that does not affect the electric conduction; laminating said inner and outer conductive circuit layers one upon another via insulating base members and joining them together; removing said insulating base members from the portions where the electric connection is to be made thereby to form holes for conduction in which said particular conductive circuit layer is exposed; forming an electrically conductive members in said hole followed by a predetermined circuit wiring patterning treatment for said outer conductive circuit layer; and forming electrically conductive bump members for connection to IC pads on said interlayer conductive members in a manner to protrude outwardly from the circuit board.

Claim 16

A method of manufacturing a multilayer circuit board for mounting ICs comprising the steps of: forming a required circuit wiring pattern on the inner conductive circuit layers except outer conductive circuit layers; removing the conductive circuit layers from portions where electric connection is to be made to a particular conductive circuit layer among said inner and outer conductive circuit layers in a size that does not affect the electric conduction; laminating said inner and outer conductive circuit layers one upon another via insulating base members and joining them together; removing said insulating base members from the portions where the electric connection is to be made thereby to form holes for connection in which said particular conductive circuit layer is exposed; effecting solder plating for said holes so that part of the solder-plating material electrically connected to said particular conductive circuit layer protrudes outwardly from the circuit board to form electrically conductive bump members for connection to IC pads; and subjecting said outer conductive circuit layer to a predetermined circuit wiring patterning treatment.

Claim 17

A method of manufacturing a multilayer circuit board for mounting ICs comprising the steps of: forming a required circuit wiring pattern on the inner conductive circuit layers except outer conductive circuit layers; removing the conductive circuit layers from portions where electric connection is to be made to a particular conductive circuit layer among said inner and outer conductive circuit layers in a size that does not affect the electric conduction; laminating said inner and outer conductive circuit layers one upon another via insulating base members and joining them together; removing said insulating base members from the portions where the electric connection is to be made thereby to form holes for connection in which said particular conductive circuit layer is exposed; effecting solder plating for said holes so that part of the solder-plating material electrically connected to said particular conductive circuit layer protrudes outwardly from the circuit board to form electrically conductive bump members for connection to IC pads; and subjecting said outer conductive circuit layer to a predetermined circuit wiring patterning treatment.