Marking Permanency




Authenticate the chip top surface and marking.


Refurbished electronic components usually have been sanded to remove the original marking, and then blacktopped - covered with a black material to hide the evidence of Sanding.


Finally, parts are remarked with a fake MFG logo and new marking including P/N and D/C, different from original.


By using Chemicals and Scrape correctly, evidence of blacktopping material, Sanding marks, and fake marking can be found.




The Threats: 


  1. Refurbished parts may not work at all, or worse, partially work for limited time or limited functions.
  2. The real D/C is different from the D/C appears on the parts marking
  3. The real P/N could be different from the P/N appears on the chip marking. For example, it can be a SMALLER capacity device, SLOWER device, LOWER temperature device, REDUCED function device, DIFFERENT Manufacturer, or a completely different device.





          Marking Permanency at GreenTree Electronics















Step 1:

Blacktopping material can been identified by a solvent swab of pure acetone, a mixture of mineral spirits and alcohol. If the parts are blacktopped, the solvents will dissolve the blacktop coating and will expose the sanding marks below it (which is exactly what the counterfeiters were trying to hide), or even expose the original marking of the Manufacturer.


Step 2:

More complex counterfeit methods can only be found while using Heated Solvents at 105° C, such as DynaSolve 750 / 711, and 1-Methyl 2-pyrrolidone. This test is performed at SMT Lab.


Step 3:

By Scraping the top surface of the device with a sharp blade, an experienced tester will be able to remove residue of blacktop material and reveal the original surface below it.




Parts will be considered suspected if: 

the fake marking is removed by Chemicals  

The original surface is revealed

Blacktop material is found on the blade edge during Scrape



Our Quality Inspection:


Microscopy Inspection

Electrical Measurement

Marking Permanency

Dimensions Measurement

Compliance to Order and Datasheet

Storing and Packaging