Method of manufacturing a multilayer circuit board

A method of making a multilayer circuit comprising the steps of:

• providing first and second circuit boards, each comprising a substrate of a non-fusing, polymer-based dielectric material and a conductive circuit formed thereon;
• providing a sheet of fusible dielectric material;
• forming a plug of fusible conductive material in said sheet of fusible conductive material;
• stacking said first and second circuit boards with said sheet of fusible dielectric material sandwiched therebetween so that said plug of fusible conductive material aligns with a selected location on each of said circuits;
• and
• laminating said stacked circuit boards under heat and pressure effective to adhere said fusible dielectric material to said non-fusing, polymer-based dielectric material and to fuse said fusible conductive material so as to form a cohesive multilayer circuit having a solid conductive interconnect between said circuits, said solid conductive interconnect being defined by said fusible conductive material.

A method of making a multilayer circuit comprising the steps of:

• providing at least one first circuit board comprising a substrate of fusible dielectric material having opposing first and second surfaces, said first circuit board further comprising a first conductive circuit formed on said first surface, said first circuit having conductive material provided on at lest one selected location thereof, said conductive material being exposed at said second surface, said conductive material at said second surface having a layer of a noble metal disposed thereon;
• providing at least one second circuit board comprising a substrate of a non-fusing, polymer-based dielectric material and a second conductive circuit formed thereon, said second conductive circuit including a layer of noble metal material on at least one selected location thereof;
• stacking said first and second circuit boards one on top of the other so that said selected location of noble metal on said first circuit board aligns with said selected location of noble metal on said second circuit board;
• and
• laminating said stacked circuit boards under heat and pressure effective to adhere said fusible dielectric material to diffuse said noble metal so as to form a cohesive multilayer circuit having a solid conductive interconnect between said first and second circuits, said solid conductive interconnect being defined by said noble metal.

A method of making a multilayer circuit comprising the steps of:

• providing first and second circuit boards, each comprising a substrate of a non-fusing, polymer-based dielectric material and a conductive circuit formed thereon, said conductive circuit including a layer of a noble metal material on at least one selected location thereof;
• providing a sheet of fusible dielectric material having at least one opening therethrough;
• stacking said first and second circuit boards with said sheet of fusible dielectric material sandwiched therebetween so that said noble metal on each of said first and second circuit boards align within said opening of said fusible dielectric material;
• and
• laminating said stacked circuit boards under heat and Pressure effective to adhere said fusible dielectric material to said a non-fusing, polymer-based dielectric material and to diffuse said noble metal so as to form a cohesive multilayer circuit having a solid conductive interconnect between said first and second circuits, said solid conductive interconnect being defined by said noble metal.