A method of wide applicability for cleaning and etching electronic materials

At the 1956 PGED meeting, D. E. Koontz and D. O. Feder discussed several methods for removing organic contaminants from electronic devices. This paper describes a simple chemical process which greatly reduces the effort required to produce components which are free of hydrophobic organic contaminants. The simplified method requires treatment of the component in an aqueous mixture of formic acid and hydrogen peroxide followed by a thorough rinsing with ultra pure water. In addition to removing organic contaminants, the bath is useful for etching certain metals. Metals such as copper, nickel, iron, and Kovar can be etched to varying degrees. Certain other metals such as titanium, tantalum, and zirconium are not etched.