Additive adhesive based process for the manufacture of printed circuit boards

A method for producing a conductive pattern on predefined regions of at least first and second surfaces of a substrate, said method comprising the steps of:

• forming at least one hole in said substrate, wherein the hole extends from the predefined region on the first surface to the corresponding pre-defined region on the second surface;
• coating each of said pre-defined regions on said first and second surfaces with a seed layer in the shape of a desired conductive pattern of at least one trace and a pad to appear thereon, wherein the seed layer is comprised of conductive particles dispersed throughout a binder capable of adhering to said substrate;
• coating substantially all the surface area of the wall of said hole with said seed layer;
• attaching the substrate to a suitable electrode such that electrical contact is established between the electrode and the seed layer appearing on the first surface of the substrate, so that electric plating current is able to flow from said electrode, via the seed layer appearing thereon and comprising the pad appearing on the first surface and via the seed layer appearing on the wall of the hole, to the seed layer appearing on the second surface;
• immersing the electrode and the substrate attached thereto into a suitable electro-plating solution;
• and
• causing the electric plating current to flow for a predefined interval of time, from one surface of the substrate to the other while said substrate is immersed in said solution, whereby a conductive layer of appropriate thickness is electrolytically deposited both over the seed layer situated on the wall of the hole so as to form a plated through hole and over said second surface so as to produce the conductive pattern that is to appear thereon.

A method for producing a conductive pattern on predefined regions of at least first and second surfaces of a substrate, said method comprising the steps of:

• forming at least one hole in said substrate, wherein the hole extends from the predefined region on the first surface to the corresponding pre-defined region on the second surface;
• coating each of said pre-defined regions on said first and second surfaces with a seed layer in the shape of a desired conductive pattern of at least one trace and a pad to appear thereon, wherein the seed layer is comprised of conductive particles dispersed throughout a binder capable of adhering to said substrate;
• coating substantially all the surface area of the wall of said hole with said seed layer;
• exposing the substrate to an elevated temperature for a predetermined amount of time in order to cure the seed layer applied to said surfaces of the substrate and to the wall of the hole;
• attaching the substrate to a suitable electrode such that electrical contact is established between the electrode and the seed layer appearing on the first surface of the substrate, so that electric plating current is able to flow from said electrode, via the seed layer appearing thereon and comprising the pad appearing on the first surface and via the seed layer appearing on the wall of the hole, to the seed layer appearing on the second surface;
• immersing the electrode and the substrate attached thereto into a suitable electro-plating solution;
• and
• causing the electric plating current to flow for a predefined interval of time, from one surface of the substrate to the other while said substrate is immersed in said solution, whereby a conductive layer of appropriate thickness is electrolytically deposited both over the seed layer situated on the wall of the hole so as to form a plated through hole and over said second surface so as to produce the conductive pattern that is to appear thereon.