Electroless plating of through-holes using pressure differential

Claim 1

A process for electrolessly plating flat articles having apertures defined therethrough comprising the steps of: (a) treating the surface of the article to be plated by immersing said article into a solution containing a stannous salt; (b) catalyzing said article by immersing it in solution for providing catalytic nucleating centers on the surface thereof; (c) treating the catalyzed surface of said article by immersing it in an electroless solution including a salt of the metal and a reducing agent; (d) creating a pressure difference within said electroless solution such that said solution impinges against a first surface of said article and is sucked away from the opposing surface of said article; and whereby said electroless solution flows through said apertures for providing intimate contact and exposure of the walls of said apertures to said electroless solution.

Claim 14

A method for treating an article with an electroless plating solution comprising: (a) at least partially immersing the article in the solution; and (b) creating a pressure difference within the solution, wherein the solution impinges onto a first surface of the article and is sucked away from a second surface of the article opposite the first surface, wherein the step of creating the pressure difference comprises: (i) from a first preselected distance away from the first surface, directing the solution toward the first surface; and (ii) at a second preselected distance away from the second surface, sucking the solution away from the second surface, whereby the first and second surfaces are thoroughly subjected to the solution.

Claim 15

A method for treating an article with an electroless plating solution comprising: (a) at least partially immersing the article in the solution; and (b) creating a pressure difference within the solution, wherein the solution impinges onto a first surface of the article and is sucked away from a second surface of the article opposite the first surface, wherein the step of creating the pressure difference comprises: (i) from a first preselected distance away from the first surface, directing the solution toward the first surface; and (ii) at a second preselected distance away from the second surface, sucking the solution away from the second surface, whereby the first and second surfaces are thoroughly subjected to the solution.

Claim 26

A method for treating an article using a solution, by electroless plating, comprising: (a) at least partially immersing the article in the solution; and (b) creating a pressure difference within the solution, wherein the solution impinges onto a first surface of the article and is sucked away from a second surface of the article opposite the first surface, wherein the step of creating the pressure difference comprises: (i) from a first preselected distance away from the first surface, directing the solution toward the first surface; and (ii) at a second preselected distance away from the second surface, sucking the solution away from the second surface, whereby the first and second surfaces are thoroughly subjected to the solution.

Claim 27

A method for treating an article using a solution, by electroless plating, comprising: (a) at least partially immersing the article in the solution; and (b) creating a pressure difference within the solution, wherein the solution impinges onto a first surface of the article and is sucked away from a second surface of the article opposite the first surface, wherein the step of creating the pressure difference comprises: (i) from a first preselected distance away from the first surface, directing the solution toward the first surface; and (ii) at a second preselected distance away from the second surface, sucking the solution away from the second surface, whereby the first and second surfaces are thoroughly subjected to the solution.

Claim 28

A method for treating an article having apertures defined therethrough with an electroless plating solution comprising: (a) at least partially immersing the article in the solution; (b) supporting the article such that first and second planar surfaces of said article are substantially parallel to and between a pair of first and second facingly disposed manifolds, whereby each manifold has a matrix of closely spaced holes defined through the inward facing surface thereof, and whereby the first and second manifolds, respectively, are a preselected distance away from the first and second planar surfaces of said article; and (c) creating a pressure difference within said solution, wherein the solution impinges onto the first surface of the article and is sucked away from the second surface of the article opposite the first surface, wherein the step of creating the pressure difference comprises: (i) directing the solution through the matrix of holes of said first manifold such that the solution impinges against the first surface of said article; and (ii) sucking the solution through said apertures defined through said article such that the solution is sucked away from the second surface of said article and toward the second manifold, whereby the first and second surfaces and apertures of said article are thoroughly subjected to the solution.

Claim 29

A method for treating an article having apertures defined therethrough with an electroless plating solution comprising: (a) at least partially immersing the article in the solution; (b) supporting the article such that first and second planar surfaces of said article are substantially parallel to and between a pair of first and second facingly disposed manifolds, whereby each manifold has a matrix of closely spaced holes defined through the inward facing surface thereof, and whereby the first and second manifolds, respectively, are a preselected distance away from the first and second planar surfaces of said article; and (c) creating a pressure difference within said solution, wherein the solution impinges onto the first surface of the article and is sucked away from the second surface of the article opposite the first surface, wherein the step of creating the pressure difference comprises: (i) directing the solution through the matrix of holes of said first manifold such that the solution impinges against the first surface of said article; and (ii) sucking the solution through said apertures defined through said article such that the solution is sucked away from the second surface of said article and toward the second manifold, whereby the first and second surfaces and apertures of said article are thoroughly subjected to the solution.

Claim 39

A method for treating a substantially planar article having apertures defined therethrough with an electroless plating solution comprising: (a) at least partially immersing the article in the solution; (b) supporting the article such that first and second planar surfaces of said article are substantially parallel to and between a pair of first and second facingly disposed manifolds, whereby each manifold has a matrix of closely spaced holes defined through the inward facing surface thereof, and whereby first and second manifolds, respectively, are a preselected distance away from the first and second planar surfaces of said article; (c) creating a pressure difference within said solution, wherein the solution impinges onto the first surface of the article and is sucked away from the second surface of the article opposite the first surface, wherein the step of creating the pressure difference comprises: (i) directing the solution through the matrix of holes of said first manifold such that the solution impinges against the first surface of said article; (ii) sucking the solution through said apertures defined through said article such that the solution is sucked away from the second surface of said article and toward the second manifold, whereby the first and second surfaces and apertures of said article are thoroughly subjected to the solution; (d) periodically reversing the direction of said pressure difference within said solution such that said impingement and suction of said solution alternately operate on said first surface and said opposing second surface of said article, whereby said flow of solution correspondingly reverses direction; (e) injecting air into said solution; (f) pumping said solution between said first manifold and said second manifold by means of a pair of oppositely directed centrifugal pumps each independently interconnecting said first manifold and said second manifold; (g) pumping said solution through a filter such that particulates are removed from said solution; and (h) directing a bracket supporting said article back and forth along a track, whereby the article is oscillated substantially perpendicularly to the line of force of said pressure difference.

Claim 40

A method for treating a substantially planar article having apertures defined therethrough with an electroless plating solution comprising: (a) at least partially immersing the article in the solution; (b) supporting the article such that first and second planar surfaces of said article are substantially parallel to and between a pair of first and second facingly disposed manifolds, whereby each manifold has a matrix of closely spaced holes defined through the inward facing surface thereof, and whereby first and second manifolds, respectively, are a preselected distance away from the first and second planar surfaces of said article; (c) creating a pressure difference within said solution, wherein the solution impinges onto the first surface of the article and is sucked away from the second surface of the article opposite the first surface, wherein the step of creating the pressure difference comprises: (i) directing the solution through the matrix of holes of said first manifold such that the solution impinges against the first surface of said article; (ii) sucking the solution through said apertures defined through said article such that the solution is sucked away from the second surface of said article and toward the second manifold, whereby the first and second surfaces and apertures of said article are thoroughly subjected to the solution; (d) periodically reversing the direction of said pressure difference within said solution such that said impingement and suction of said solution alternately operate on said first surface and said opposing second surface of said article, whereby said flow of solution correspondingly reverses direction; (e) injecting air into said solution; (f) pumping said solution between said first manifold and said second manifold by means of a pair of oppositely directed centrifugal pumps each independently interconnecting said first manifold and said second manifold; (g) pumping said solution through a filter such that particulates are removed from said solution; and (h) directing a bracket supporting said article back and forth along a track, whereby the article is oscillated substantially perpendicularly to the line of force of said pressure difference.