process for plating lead frames

face portion of each of at least two electri­cally conductive workpieces using anelectrolyte, said apparatus comprising afirst tank having an interior defined in partby a wall having at least two aperturesformed therein and a drain; at least oneelectrode extending into the first tank;means mounted on the first tank for tem­porarily securing each of the workpiecesrelative to each of the apertures; sealingmeans disposed between each of the work­pieces and each of the apertures, such thatonly the first surface portions of the work­pieces are placed in fluid communicationwith the interior of the first tank; a secondtank for containing the electrolyte; meansfor directing the electrolyte from the sec­ond tank into the first tank, such that theelectrolyte bridges each of the workpiecesand the at least one electrode; and a powersupply for applying a current across theelectrolyte, where an electrolytic coating issimultaneously generated on the first sur­face portion of each of the workpieces.

Process for Plating LeadFramesu.s. Patent 5,750,016. May 12, 1998S-S. Moon, Pusan, Rep. of Korea

A process for plating palladium or apalladium alloy onto an iron-nickel alloysubstrate, which comprises plating a metalselected from the group consisting of cop­per, tin, a nickel-tin alloy, and a copper-tinalloy onto the substrate to form a firstprimer layer; plating nickel or a gold alloyonto the first primer layer to form a secondprimer layer; and plating palladium or apalladium alloy onto the second primerlayer to form a palladium or a palladiumalloy layer.

Tin Electroplating Processu.s. Patent 5,750,017. May 12, 1998Y. Zhang, assignor to Lucent Technologies Inc.,Murray Hill, N.J.

A process for electroplating tin or tinalloy onto a metal substrate comprisingplacing in an aqueous plating bath compris­ing a stannous sulfonate selected from thegroup consisting of stannous alkyl sul­fonate and stannous alkoyl sulfonate, a sul­fonic acid selected from the group consist­ing of alkyl sulfonic acid or alkoyl sulfonicacid, and at least one organic additive thatis an organic compound with at least oneheterocyclic moiety, wherein the sulfonic

acid in the bath has a concentration that issufficient to provide the bath with a pH ofabout I or less and the organic additive inthe bath has a concentration of 0.08 to 0.8gIL; introducing a pulsed current into thebath under conditions sufficient to providea tin or tin alloy coating on the substratewith well-polygonized grains having an av­erage grain size of 2 urn to 8 flm.

Cyanide-Free Copper PlatingSolutionu.s. Patent 5,750,018. May 12, 1998W.R. Brasch, assignor to LeaRonallnc., Freeport,N.Y

A method of plating copper onto a sub­strate, which comprises preparing a cya­nide-free monovalent copper plating solu­tion by mixing a source of copper ions, areducing agent capable of reducing diva­lent copper ions to monovalent copperions, an alkali material in an amount suffi­cient to maintain the solution in a pH rangeof 7 to 10, and a complexing agent of animide or hydantoin compound, wherein thecombined amount of complexing agent andreducing agent are sufficient to reduce di­valent copper ions to monovalent copper

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