Additive printed circuit boards with flat surface and indented primary wiring conductors

Claim 3

The method of claim 1 including the steps of forming the photopolymer layer with a thickness of about 0.006 inch, and forming the channels with a width of about 0.003 inch.

Claim 4

The method of claim 1 including the step of treating the surface of the substrate with the pattern therein with a catalytic material for enhancing electroless copper deposition and depositing said conductor as an electroless copper layer thereover.

Claim 5

The products produced by claim 1.

Claim 6

In an additive method of printing primary wiring patterns onto insulating substrates, the improvement comprising the steps of: establishing a desired printed wiring pattern on an insulating panel by forming a substantially flat surface over the panel by depositing thereon a layer of liquid photopolymer insulating material, defining by photographically forming and developing in said layer patterns of a plurality of conductor lines indented from said flat surface with insulation barriers of hardened photopolymer dispersed between adjacent conductor lines of the patterns, with the conductor lines patterns comprising indented channels in the hardened photopolymer layer presenting substantially perpendicular to the panel adjacent sidewalls of substantially the thickness of the patterned layer, forming simultaneously thin film metallic conductors in the channel bottoms, on the flat top surface, and on the opposing channel sidewalls above the metallic conductors in the bottoms thereby extending the conductor with available between adjacent conductors by substantially twice the thickness of the photopolymer layer, and, removing any conductive material on the substantially flat top surface of the patterned layer thereby to define by photographic exposure and development of the photopolymer layer an insulation gap of known dimensions between adjacent conductors and to form a primary wiring pattern of conductors indented in the photopolymer layer.

Claim 7

In an additive method of printing primary wiring patterns onto insulating substrates, the improvement comprising the steps of: establishing a desired printed wiring pattern on an insulating panel by forming a substantially flat surface over the panel by depositing thereon a layer of liquid photopolymer insulating material, defining by photographically forming and developing in said layer patterns of a plurality of conductor lines indented from said flat surface with insulation barriers of hardened photopolymer dispersed between adjacent conductor lines of the patterns, with the conductor lines patterns comprising indented channels in the hardened photopolymer layer presenting substantially perpendicular to the panel adjacent sidewalls of substantially the thickness of the patterned layer, forming simultaneously thin film metallic conductors in the channel bottoms, on the flat top surface, and on the opposing channel sidewalls above the metallic conductors in the bottoms thereby extending the conductor with available between adjacent conductors by substantially twice the thickness of the photopolymer layer, and, removing any conductive material on the substantially flat top surface of the patterned layer thereby to define by photographic exposure and development of the photopolymer layer an insulation gap of known dimensions between adjacent conductors and to form a primary wiring pattern of conductors indented in the photopolymer layer.

Claim 8

The products produced by claim 5.

Claim 9

The additive method of processing printed wiring boards to produce primary circuit patterns thereon, comprising the steps of: providing a basic substrate panel with a substantially flat surface subject to irregularities from flatness of the order of at least 0.001 inch, depositing thereover a layer of liquid photopolymer of pastelike consistency having a thickness of greater than 0.002 inch, photoprinting with a flat glass plate image bearing body in contact with the liquid polymer to produce a flat surface thereon and a surface contour having said flat surface and a wiring pattern disposed in the layer of polymer on the substrate panel defined by channels indented downwardly from the flat surface into the polymer layer to have sidewalls substantially perpendicular to the substrate panel, simultaneously depositing in the bottoms of the channels and extending upwardly on the sidewalls above the deposits in the bottoms a thin film layer of metallic conductor to form the wiring patterns whereby the width of the conductors is effectively increased by the heights of the two sidewalls, and machining off any residue conductor on the top flat surface to assure a predetermined width of insulation barrier between adjacent conductors.

Claim 10

The additive method of processing printed wiring boards to produce primary circuit patterns thereon, comprising the steps of: providing a basic substrate panel with a substantially flat surface subject to irregularities from flatness of the order of at least 0.001 inch, depositing thereover a layer of liquid photopolymer of pastelike consistency having a thickness of greater than 0.002 inch, photoprinting with a flat glass plate image bearing body in contact with the liquid polymer to produce a flat surface thereon and a surface contour having said flat surface and a wiring pattern disposed in the layer of polymer on the substrate panel defined by channels indented downwardly from the flat surface into the polymer layer to have sidewalls substantially perpendicular to the substrate panel, simultaneously depositing in the bottoms of the channels and extending upwardly on the sidewalls above the deposits in the bottoms a thin film layer of metallic conductor to form the wiring patterns whereby the width of the conductors is effectively increased by the heights of the two sidewalls, and machining off any residue conductor on the top flat surface to assure a predetermined width of insulation barrier between adjacent conductors.

Claim 11

The method of claim 7 including the steps of applying a catalytic layer to the contoured surface over the flat surface and in the indented channel portions thereof, and electroless depositing conductor onto the catalytic layer before the flat surface is machined, leaving the panel surface and the polymer layer sidewalls defining the channels covered with conductor.

Claim 12

The method of claim 7 including the steps of roller coating the flat surface with an insulation material and electroplating the exposed electroless deposit in the channels only, before removing the conductor from the top flat surface.

Claim 13

The method of claim 7 including the steps of providing the photopolymer layer in a thickness greater than 0.005 inch and channel widths of about 0.002 inch thereby to achieve a polymer layer thickness to line width ratio substantially greater than one.

Claim 14

The method of claim 7 wherein the mechanical step of removing conductor from the flat surface comprises sanding the surface.

Claim 15

The method of claim 7 wherein said catalytic layer is machined from said flat surface prior to the deposition of electroless conductor, thereby limiting the build up of conductor to the indented channels.

Claim 16

The method of claim 12 including the step of confining the residue of said machining step so as to facilitate the recovery of the precious metal therein.

Claim 17

The products produced by claim 7.