Laser induced selective electroless plating

Claim 1

A method for selectively plating a metal onto a workpiece which consists essentially of the steps of (a) applying a sensitizing solution to said workpiece, thereby providing a sensitized workpiece, (b) describing a pattern on said workpiece by flash evaporating sensitizer from said workpiece by directing a laser beam onto the thus-sensitized workpiece in an area which is not to receive said metal plated thereon, and (c) contacting said workpiece with an electroless plating solution to achieve plating in areas wherein said sensitizer remains.

Claim 2

A method for selectively plating a metal onto a workpiece which consists essentially of the steps of (a) applying a sensitizing solution to said workpiece, thereby providing a sensitized workpiece, (b) describing a pattern on said workpiece by flash evaporating sensitizer from said workpiece by directing a laser beam onto the thus-sensitized workpiece in an area which is not to receive said metal plated thereon, and (c) contacting said workpiece with an electroless plating solution to achieve plating in areas wherein said sensitizer remains.

Claim 11

A method for selectively plating a metal onto a workpiece which consists essentially of the steps of (a) mounting a workpiece in a plating vessel comprising a housing, a cover which is transparent to laser radiation, inlet means for introducing a fluid into said vessel and outlet means for withdrawing a fluid from said vessel; (b) introducing a sensitizing solution into said vessel while withdrawing therefrom any residual fluid previously therein, to thereby coat said workpiece with a layer of said sensitizer solution; (c) introducing an inert liquid media into said vessel while withdrawing therefrom said sensitizer solution, thereby flushing excess sensitizer solution from said vessel; (d) describing a pattern on said workpiece by flash evaporating sensitizer from said workpiece by directing a laser beam through said transparent cover and said inert liquid and onto the thus-sensitized workpiece in an area which is not to receive said metal plated thereon; and (e) introducing an electroless plating solution into said vessel while withdrawing therefrom said inert liquid and maintaining said plating solution in contact with the thus-plated sensitized workpiece for a time sufficient to obtain a desired plating deposit.

Claim 12

A method for selectively plating a metal onto a workpiece which consists essentially of the steps of (a) mounting a workpiece in a plating vessel comprising a housing, a cover which is transparent to laser radiation, inlet means for introducing a fluid into said vessel and outlet means for withdrawing a fluid from said vessel; (b) introducing a sensitizing solution into said vessel while withdrawing therefrom any residual fluid previously therein, to thereby coat said workpiece with a layer of said sensitizer solution; (c) introducing an inert liquid media into said vessel while withdrawing therefrom said sensitizer solution, thereby flushing excess sensitizer solution from said vessel; (d) describing a pattern on said workpiece by flash evaporating sensitizer from said workpiece by directing a laser beam through said transparent cover and said inert liquid and onto the thus-sensitized workpiece in an area which is not to receive said metal plated thereon; and (e) introducing an electroless plating solution into said vessel while withdrawing therefrom said inert liquid and maintaining said plating solution in contact with the thus-plated sensitized workpiece for a time sufficient to obtain a desired plating deposit.

Claim 19

A method for continuously plating a metal onto a workpiece which consists essentially of the steps of coating a linearly moving flexible workpiece with a sensitizer, positioning a linearly moving photomask in contact with the thus-sensitized workpiece, moving said sensitized workpiece and said photomask through a laser beam positioned so that the said beam is directed onto said mask and through selected portions thereof onto said workpiece, whereby the portion of light passing through said selected portions flash evaporates said sensitizer from said sensitized workpiece, separating said photomask from the resulting pattern -sensitized workpiece, and contacting said pattern-sensitized workpiece with an electroless plating solution for a time sufficient to achieve a desired level of plating thereon.

Claim 20

A method for continuously plating a metal onto a workpiece which consists essentially of the steps of coating a linearly moving flexible workpiece with a sensitizer, positioning a linearly moving photomask in contact with the thus-sensitized workpiece, moving said sensitized workpiece and said photomask through a laser beam positioned so that the said beam is directed onto said mask and through selected portions thereof onto said workpiece, whereby the portion of light passing through said selected portions flash evaporates said sensitizer from said sensitized workpiece, separating said photomask from the resulting pattern -sensitized workpiece, and contacting said pattern-sensitized workpiece with an electroless plating solution for a time sufficient to achieve a desired level of plating thereon.