US 5,326,453 A · Method and solution for electrodeposition of a dense, reflective tin or tin-lead alloy

Abstract

New formulations for the electrodeposition of a dense, reflective tin or tin-lead alloy on a cathode have been developed. Such electrodeposition solutions are partially comprised of an additive which is comprised of at least one nonionic surfactant which is electrolyzed prior to starting the electrodeposition process. The electrodeposition solution is also comprised of an amount of an aliphatic dialdehyde kept low enough so that the solder deposits contain no more than 500 ppm of co-electrodeposited carbon. The additive and the aliphatic dialdehyde is mixed with a solution comprised of an alkane or alkanol sulfonic acid and a tin alkane or alkanol sulfonate or a mixture of a tin and lead alkane or alkanol sulfonate to form an electrodeposition solution. A dense, reflective finish is then electrodeposited on a cathode by using such an electrodeposition solution.

Claims23

Dependent claims

An electrodeposition solution for electrodepositing a tin or tin-lead alloy on a cathode, comprising:

an alkane or alkanol sulfonic acid and a tin alkane or alkanol sulfonate or a mixture of a tin and lead alkane or alkanol sulfonate;
a modified additive comprised of at least one nonionic surfactant, wherein an additive is electrolyzed prior to electrodepositing a tin or tin-lead alloy on a cathode to form the modified additive;
and
an aliphatic dialdehyde.

1 more element

A method of forming a tin or tin-lead alloy electrodeposition solution, comprising the steps of:

providing an additive comprised of a nonionic surfactant;
electrolyzing the additive to form a modified additive;
and
mixing the modified additive with an aliphatic dialdehyde, an alkane or alkanol sulfonic acid, and a tin alkane or alkanol sulfonate or a mixture of a tin and lead alkane or alkanol sulfonate to form the electrodeposition solution.

1 more element

A method of electrodepositing a tin or tin-lead alloy on a cathode, comprising the steps of:

electrolyzing an additive comprised of a nonionic surfactant to form a modified additive;
providing a solution comprised of an alkane or alkanol sulfonic acid and a tin alkane or alkanol sulfonate or a mixture of a tin and lead alkane or alkanol sulfonate;
providing an aliphatic dialdehyde;
forming an electrodeposition solution by mixing the modified additive with the solution comprised of the alkane or alkanol sulfonic acid and the tin alkane or alkanol sulfonate or the mixture of a tin and lead alkane or alkanol sulfonate and the aliphatic dialdehyde;
and
using the electrodeposition solution comprised of the modified additive to electrodeposit the tin or tin-lead alloy on the cathode.

3 more elements

Dependencies are inferred from the claim text.

Method and solution for electrodeposition of a dense, reflective tin or tin-lead alloy

Life of this patent

Method and solution for electrodeposition of a dense, reflective tin or tin-lead alloy

Life of this patent

Abstract

Claims23