Organic solderability preservative compositions
AssigneeNational Research Council of Canada
InventorsKenneth C. Cole, Eric Pellerin
Life of this patent
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Abstract
Known organic solderability preservatives (OSP) contain an azole compound and are applied on a copper surface from an acidic solution. The OSPs are not visible to the naked eye when applied. A number of dyes compatible with the OSP solution and not interfering with solderability has been identified. The composition containing such a dye can produce a layer which is visible to the naked eye when applied even in a thin layer. The suitable dyes contain a cationic imine group having the general formula ##STR1## where X.sup.- is an anion such as chloride, iodide, sulphate, etc., or an organically bonded anionic group such as sulphonate.
Claims6
A composition for preserving solderability of a metal surface, the composition comprising
- an azole compound effective to provide a solderability protective layer on a metal surface, and
- a dye containing a cationic imine group having the general formula ##STR66## where X.sup.- is an anion or an anionic group, the anion or anionic group selected to afford a solubility of the dye in the azole compound, the deposition of the azole compound on the metal surface, and solderability of the metal surface.
Dependencies are inferred from the claim text.