Widespread concern is increasing for the need to secure your supply chain and protect yourself against counterfeit products. In the first instance, the key is to use suppliers with full trace-ability all the way back to the manufacturer. When you have no alternative to go to the gray market there are a whole host of tools that you can use to ensure that you are not purchasing counterfeit products as they get more and more sophisticated. If you do not have direct access to these tools then use a reputable company to do it for you.
Counterfeit detection tools include:
Visual Inspection The first step is a simple visual inspection by a trained specialist. In the past counterfeits were crude and basic, things such as label markings and logos being nothing like the original were easy to spot if you are familiar with the brand. You should also inspect all of the packaging and product documentation including shipping information such as language used.
Acetone Testing Previously an acetone test would have been sufficient to pick up black-topped counterfeits. This is a simple rub test with a cotton bud and soaked in acetone where if the cotton bud turns black the device has failed. Nowadays counterfeiters are getting smarter with the black-topping they are using to cover the top surface of the component. The test now involves using a variety of different solvents to break down different black-top materials.
De-capsulation is a process that etches away, using a harmful combination of chemicals, the compound that encapsulates the silicon inside of an integrated circuit. This allows inspection of the internal components of the package such as the die (silicon chip) and interconnects (wire bonds). A magnified image of the silicon will usually show the manufacturers mark or logo along with information that pertains to the manufacturers part number. The die may also indicate when it was made. This information can be checked against the information on the top surface of the chip and any packaging that is available.
Curve trace testing - Retronix
Curve tracing techniques allow us to confirm basic facts about a suspect device. The basic concept is that each pin possesses a characteristic Voltage-Current relationship unique to the electrical structure and manufacturing process used to make the device. Curve traces can be compared to other unknown and known device signatures and evaluated for a match (http://www.retronix.co.uk).
Scanning Electron Microscopy (SEM)
It is important to rely on more than a basic visual inspection. Differences in the surface texture from a known good device would suggest tampering. It is also often useful to compare top and bottom surfaces as the counterfeiters are normally altering just the top surface. According to Susan Swapp at the University of Wyoming:
"SEM uses a focused beam of high-energy electrons to generate a variety of signals at the surface of solid specimens revealing information about the sample including external morphology (texture), chemical composition, and crystalline structure and orientation of materials making up the sample."
Energy Dispersive X-Ray Spectroscopy (EDS) inspection This allows an elemental and chemical analysis of a sample breaking down all of the elements.
Over and above the conventional counterfeit detection techniques already discussed new practices are now being introduced as a way of keeping one step ahead of the counterfeiters.
Chemical fingerprints (Lutracore) have been developed by Infra Trac and Cardinal Components. Source: http://www.lutracore.com/#about.
"The chemical fingerprint is composed of several commodity chemicals grouped together to create a code, that can be detected in seconds anywhere in the supply chain by a technician with less than an hour of training. The test is a non-destructive procedure that provides verification without destroying the product being tested."
Plant DNA which is being developed by Applied DNA Sciences and LMI provides a forensic chain of evidence. Click here for more information.
Staff training is also vital to ensure that those handling the electronic components in the warehouse are familiar with brands. Staff should be knowledgeable on how to detect counterfeits and capable of completing all necessary testing on the products. Essentially you should not only inspect and test all electronic components but you should scrutinise your supply chain too. Anne-Liese Heinichen from ERAI, Inc published a blog article "Enhancing Your Supplier Verification Process" on 4 December 2017:
With the release of DFARS 252.246.7008, supplier qualification requirements remain front and center in the US Government’s efforts to prevent counterfeit parts from entering the military supply chain. Of importance, not only to government contractors, is the topic of supplier assessment as a key element in every organization’s documented mitigation program/control plan.
We are an approved supplier to the US Military: Cage Code Number U0PN5. Component Sense also offers a consultancy service and training on counterfeit detection. Contact us today to discuss your counterfeit detection requirements in more detail.