|State-of-the-art tester, Teradyne's Ultraflex-HD is used in-house by DPA Components for testing suspect ICs. Photo Copyright: Teradyne, Inc.
With an ever-growing number of counterfeit concerns, there are many analysis techniques available for rooting them out. It's important that trained experts use these tools to assure a company that its component inventory is authentic. Focus therefore must be dedicated to uncovering the counterfeit components, purging them from inventory and learning from these causes.
The Paper Chase
The best way to reduce the chance of counterfeit inventory: buy from the Original Component Manufacturer (OCM) or their franchised distributors only. With this purchase, these manufacturers deliver a certificate of compliance. Thus there is a direct transfer of this information to the end user. This also translates into a need to greatly reduce purchases from specialty vendors.
It is important to reduce the number of transactions against any given lot of material. Procure, process, test, certify and ship from the same company if possible. Reducing the processing and shipping reduces the likelihood of misprocessing or clerical error. Less outsourcing means fewer shipments, which each require individual certificates of compliance. The fewer certificates of compliance needed, thus the fewer shipments, the less opportunity there is for not having complete, accurate documentation
Furthermore, when buying larger quantities, the components benefit from economies of scale, both for the cost of the components and the cost of changing programs to meet such requirements as testing, burn-in, and environmental impact. This can help to keep project costs under control.
Every device has a true origin but the act of relocating the product further away from this source either by paper certifications and/or device processing will increase the probability for tampering, misrepresentation. The greater the imbalance between the documentation and the physical product authenticity, the higher the probability of counterfeits appearing.
Could the devices be stolen goods? This can happen if a shipment of semiconductors is "hijacked". Delivery trucks transporting freshly manufactured product have been known to be illegally boarded, diverted and robbed of massive shipments of freshly tested ICs. This unauthorized transfer of perfectly respectable components in itself classifies the components aboard the truck as "counterfeit". The product may merely be sold on the black market as the "same as original", losing only its resale certification; in such cases, the device's performance integrity remains intact. This is good product, but is undocumented because we are dealing with stolen goods. The product could continue to flourish in the supply chain until consumed in the manufacture of an end product.
However, that stolen shipment could take an alternative path containing a new and misleading identity. Specifically, the thief may only want to utilize certain selected component package types from the stolen shipment — items that he may already have orders for. The thieves will then remark other, unsalable packages, promoting them as other devices from the same family and manufacturer — in bona fide original packages from the OEM. All they have to do is match up the pin count and package, paint out the original device number, and print whatever they want on the topside and sell as new. They often leave the OEM logo intact and simply change the part number itself. With the lot number, date code and other subsequent marking information remaining as per the original manufacturer's production marking diagrams, it is difficult to detect the forgery by visual inspection alone. However, the documentation will be missing.
What's wrong here, is that while the device may be perfectly good, it is mislabeled and will therefore be used incorrectly. It is a forgery — a good product that have been relabeled with a different part number, and this can spell disaster for the end user. The sheer quantity of such illegitimate "promotional"
misrepresentations are vast and have repeatedly shown a large degree of criminal activity — the buyer must beware!
Part Number Comparisons
If the parts make it through the supply channels based on a part number comparison check alone, then the problem surely begins. On the back end, by the time the end customer tests them discovering the fake IC, the thief is long gone — with the customer's money. Discovering that the just-purchased IC batch — similar to, but not the same as the desired IC — often requires detailed electrical testing or screening to discover. Perhaps a die revision change alone could change or disable key parameters rendering the device non-functional in the intended application. The difference in these device parameters may further add risk to the complete system functions if the device is used to build a product. Beneath the freshly drying bogus marking, may lurk a ticking time bomb component. It may have just enough shared characteristics with the intended device to fool some incoming testing, but the rest of its characteristics will be seriously out of spec or missing, causing failure of the final, assembled product.
Regardless of the paperwork trail's purity, there are very few ways to be sure the paperwork indeed matches the exact batch of components being received. And how do we know that even the paperwork hasn't been forged? Purchasing "read and record" test data with a lot of parametrically dense ICs would be very desirable in order to "signature" the device's electrical contribution to detailed system performance.
|The complexity of today's digital ICs often makes testing them a challenge.
Without franchised protection for the transfer of the data and components together, there are no assurances that the data sold matches the devices in the lot as claimed. There is no way for buyers to make this determination themselves unless they have in-house time and capabilities including, characterization, equipment and a knowledgeable testing staff to perform the needed operations. This lack of adequate verification safeguards may result in these devices moving on towards the end equipment where they are installed and system tested. These system tests may or may not reveal the device's deficiencies. The counterfeits are in place, but tests may not reveal their presence — at least not right away. In the worst case scenario, the suspect components are installed in a flight-ready, mission critical project, pass the initial system checks yet are definitely not suitable for flight.
How then, is it possible to mitigate the risk of counterfeit or non-authentic components? There are many ways to reduce the risk of counterfeit components. After an initially solid procurement system, a good prevention plan consists of a number of value-added testing and analysis solutions used to detect and categorize the authenticity of suspect/counterfeit components.
The plan should span both the breadth of products purchased as well as the depth of test details required to properly investigate each product type.
SAE Standard "AS5553" contains detection and mitigation flows to assist in this classification. Qualified test laboratories perform the following services in order to support plan compliance. Suppliers/subcontractors must conform to the same quality system requirements governing the project and parties involved. Component authentication can involve one or several test procedures:
- Documentation and packaging inspection,
- Visual inspection.
- Remarking/resurfacing inspection.
- X-Ray inspection.
- X-Ray fluorescence.
- Destructive physical analysis (DPA).
- Thermal cycle testing.
- Electrical testing.
- Hermeticity verification.
- Other tests (acoustic microimaging), etc.).
Successful implementations of most or all of these services contribute to authenticity verification because positive results from these tests help remove worry over each individual risk factor affecting the component. Results can be valuable in partial form but taken as a whole, these sets of tests are most beneficial in resolving the true identity of a suspect device.
Visual inspection of a package can easily determine if the correct number of leads are available but how those leads are connected to the die or what die is inside for that matter are of critical importance also! Verification of construction integrity would be impossible without this confirmation. Accordingly, a Curve Tracer or ATE Electrical test might then be applied to further confirm that each lead receives the proper signal or response. Erratic behavior under test may elicit additional, more complicated electrical tests including opening of the package for full die microscopic inspection.
Tests should be conducted with proper consideration; obviously, destructive testing means the component is lost and can only provide a "spot-check" indication for a given batch. Non-destructive testing, on the other hand, means that the component can ultimately be used if it passes; but positive identification can be costly and time-consuming, as indicated by the many types of tests that can be performed. Many lot-dispositioning activities are affected by results of these investigative and preventive procedures, so the exact test flows should be carefully reviewed with your testing partner.
Contact: DPA Components International, 2251 Ward Avenue, Simi Valley, CA 93065 805-581-9200 fax: 805-581-9790 E-mail: Kirk@dpaci.com or email@example.com Web: http://www.dpaci.com