Electrolytic process for producing lead sulfonate and tin sulfonate for solder plating use
US5618404A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1995 |
| Grant date | Apr 8, 1997 |
| Priority date | — |
| Expiry date | May 16, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC25D3/60
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
An electrolytic process for producing lead and tin sulfonates which comprises applying a DC voltage to an anode and a plurality of cathodes in an electrolytic cell and thereby dissolving lead or tin in an electrolytic solution. The electrolytic cell is partitioned by cation- and anion-exchange membranes into anode and cathode chambers. The electrolytic solution is a solution of an organic sulfonic acid, and the anode is lead or tin. The process reduces contents of radioisotopes such as uranium and thorium to a level of less than 50 ppb, and therefore the coatings formed by solder plating using the lead and tin salts in accordance with the invention show radioactive .alpha. particle counts of less than 0.1 CPH/cm.sup.2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.