National Physical Laboratory

Solvent Extract Conductivity (SEC) / Ionic Extraction Testing

Solvent Extract Conductivity 

Solvent Extract Conductivity (SEC) uses a mixture of isopropanol (IPA) and DI water to remove soluble contaminants from a sample PCB or PCA. The change in the conductivity of the solution used to wash the assembly provides a measure of the average ionic contamination present on the board.

SEC testing does not show the distribution of contamination, or the effects of any non-ionic residue and the result can be dependent on the components density of board and extraction efficiency.

The sensitivity of this technique can be improved by using a one-hour extraction at 80°C, increasing the sensitivity of measurement several-fold.

Using the SIR measurement technique is recommended for a more detailed investigation than SEC testing.

Common applications:

  • Testing cleanliness to MIL-Spec, IPC and other standards
  • Process control for cleaning lines
  • Cost-effective assessment technique for ranking cleaning processes


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Last Updated: 25 Mar 2010
Created: 29 Jul 2009


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