High Purity Acids / Electronics

Hi,

I am involved with a variety of ultra high purity acids for electronic etching applications. The most common acids I deal with are sulfuric acid, hydrochloric acid and HF.

My problem trying to maintain the purity of these acids to ppb levels. Any metals typically contaminate these ultra high purity acids as the ions leach into the solution. Will the Ultra-Metal tantalum surface have this same problem.

Dan

Hello Dan,

The Ultramet tantalum surface should greatly protect the purity of your acids with the exception of HF (tantalum is not corrosion resistant to HF). The reason is, most metals like nickel, titanium, steel etc. will have some form of a corrosion rate in concentrated acids like HCl or H2SO4 even at ambient temperatures. When dealing with ultra high purity acids this corrosion rate, although small, will effect the purity of your acids.

Conversely in the case of tantalum metal, it does not have a corrosion rate especially at ambient conditions. Because of the extremely tough oxide layer that protects it, a tantalum surface is unlikely to contaminate your acids.