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DETERMINATION OF Pd/Sn COLLOIDAL SEED ACTIVITY AND COMPONENT CONCENTRATION

IP.com Disclosure Number: IPCOM000057532D
Original Publication Date: 1988-May-01
Included in the Prior Art Database: 2005-Feb-15

Publishing Venue

IBM

Related People

Authors:
Bindra, P Egan, P Gilmore, M O'Sullivan, E White, J [+details]

Abstract

This is an electrochemical technique for determining, on line, the catalytic activity and composition of a typical Pd/Sn colloidal seeder bath that is commonly used today in the manufacture of electronic circuit cards or boards. A combination of palladium and stannous, called "Pd/Sn sols", is used as a colloidal seeder to form a conductive film on the electrically non-conductive cards or boards. While there are techniques already today for measuring the catalytic activity of a Pd/Sn sol, none is known that can perform this measurement in situ on a manufacturing line. To monitor Pn/Sn seed activity: A glassy carbon (GC) rotating disk electrode (RDE) is immersed for one minute in a solution of colloidal seeder, at nominal bath concentration, followed by a one-minute immersion in HCl (8 vol%).