Marking Permanency (Resistance to Solvents) Test:
The purpose of a Marking Permanency test is to verify that the component parts, when subjected to solvents, will maintain their correct markings. Counterfeit parts often have new markings which are not permanent; they will dissolve when the solvents are properly applied. Also, the solvents will reveal evidence of previous markings which have been sanded off or otherwise replaced by the false markings.
Various Military Standard procedures are used which incorporate processes of working with several chemicals mixed appropriately and in detail is in accordance with the specifications. These chemicals consist of Aliphatic alcohol, mineral spirits, ethyl-benzene, organic solvents, de-ionized water, propylene glycol monomethyl either, or monoethanloamine.
Once properly mixed the components are submerged in a three phase process and analyzed in accordance with MIL-HBK-130 to uncover evidence of damage to the device and any specified markings which are missing in whole or in part, faded, smeared, blurred, or shifted (dislodged) to the extent that they cannot be readily identified from a distance of at least 15.0cm (6 inches) with normal room lighting and without the aid of magnification or with a viewer having a magnification no greater than 3X. In some cases, a strategic acetone wash will be used to reveal sanding marks and facets of previous markings.
Blacktop marking is just one test in a multistep process used to discover counterfeit electronic components. Other tests include closely checking the physical dimensions and the packaging as well as the performance of the chips. Counterfeit electronic components are on the rise in both military and civilian products. As the counterfeiting gets more sophisticated, testing houses continue to develop finely tuned procedures to separate the fake goods from the real parts.