Low friction solder electrodeposits
AssigneeHandy & Harman
InventorsTherese R. Souza, Allen E. Molvar
Life of this patent
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Abstract
The present invention relates to a solution and method for plating tin, lead, or tin-lead alloy deposits which contain a co-deposit of fluorocarbon particles to provide a lower-friction solder-type deposit which reduces insertion force and fretting corrosion in separable electronic connectors. The fluorocarbon particles have a size between about 0.1 to 1 .mu.m in diameter, and reduce the coefficient of friction of the resultant deposit to 0.8 or less. Also, the deposit has excellent mechanical properties and can be successfully soldered.
Claims3
A method for providing a substrate with a deposit having a reduced coefficient of friction which comprises:.
- immersing the substrate into a solution comprising an alkane sulfonic acid in an amount sufficient to impart a pH below about 2 to the solution;
- at least one of a solution soluble tin compound or solution soluble lead compound in an amount sufficient to deposit tin metal, lead metal or both;
- a substantially non-foaming, non-ionic surfactant in an amount sufficient to assist in depositing a smooth, adherent, uniform deposit;
- and fluorocarbon particles having a diameter of about 0.1 .mu.m to less than 0.5 .mu.m;
- and
- electroplating thereon a reduced-friction tin, lead or tin-lead alloy deposit having a contact resistance that does not exceed about 3.5 milliohms over at least about 4,000 cycles.
Dependencies are inferred from the claim text.