The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 11, 1995
Filed:
Sep. 08, 1993
Hugh W Richardson, Sumter, SC (US);
Charles F Jordan, Sumter, SC (US);
Phibro-Tech, Inc., Ft. Lee, NJ (US);
Abstract
Copper etchant solution additives for use with an aqueous alkaline ammoniacal cupric chloride etching bath include several compounds, each of which is shown to stabilize the copper(I) state. The compounds discovered by the present invention include iodide ions such as potassium iodide, ammonium iodide, sodium iodide, calcium iodide and magnesium iodide. Other copper(I) stabilizers discovered by the present invention include certain water soluble salts containing sulfur such as a thiocyanate ion (e.g. ammonium thiocyanate, potassium thiocyanate, sodium thiocyanate, magnesium thiocyanate, and calcium thiocyanate) and a thiosulfate ion (e.g. ammonium thiosulfate, potassium thiosulfate, sodium thiosulfate, magnesium thiosulfate, and calcium thiosulfate). Etching rates for alkaline ammoniacal cupric chloride with different concentrations of potassium iodide, ammonium thiocyanate, and sodium thiosulfate were studied. The results of controlled experiments revealed that adding concentrations up to approximately 1200 mg/L of any one of these compounds to the alkaline ammoniacal cupric chloride etchant resulted in a 20-130% increase in etch rate.