It seems that every time there is a component shortage, the issues of brokers hoarding components and distributing counterfeits become major problems again. Counterfeit components are not a new problem, but counterfeits combined with hoarding of components by brokers create a perfect storm of risk for OEMs and EMS companies. When companies get desperate for parts and start looking to non-authorized distributors, they put themselves at risk of procuring fake parts.
Therefore, it’s important for companies to know what steps they can take to:
- Identify fake components in a parts kit
- Identify reputable brokers if needed
There are some inspection methods that can help identify fake components, or at least signal some deeper inspection level is required. Inspection of components involves looking at the packaging, as well as internally with destructive or non-destructive methods. There are also testing methods that can be used to determine whether parts are genuine as described in product literature and documentation.
Counterfeit Component Inspection Methods
Some of the most common attempts at counterfeiting do not involve forging components. Instead they involve misrepresenting a component. This can involve one or more of the following:
- Removing the part number from a component
- Replacing the part number with a different part number
- Modifying the part number so that the part appears to be a more expensive variant
- Sending the correct component, but the part was used and pulled from an old assembly
- Removing the die from a component
The first place to start is with a visual inspection as this can eliminate many components from a list of possible counterfeits. Other components that are high-risk or high-expense may need a more thorough examination under a microscope.
Some of the most obvious faked components can be spotted easily with a visual inspection. Sometimes a simple chemical test may be needed as part of a visual inspection if a part is initially suspected to be faked. The table below outlines some of the counterfeiting methods that can be identified during a visual inspection.
These visual checks can help identify some of the most obvious counterfeiting measures. Portions of these checks could also be automated with a vision system, although commercially available systems specifically built for component authentication are not available; everything would have to be coded from scratch.
In addition, it is certainly not the case that every component in a shipment needs to be inspected or tested. Some parts come in reels with manufacturer’s markings; an inspection of the reels and packaging should be sufficient to determine authenticity. Loose components, or repackaged components in a tray, can be a red flag as these were likely handled manually before being shipped to an assembler or customer. In that case, it’s possible that some or all of the components are mislabeled or fake.
High-quality forgeries may slip through the cracks with these checks, but those more expensive components will typically be targets for more sophisticated forgeries. These components, and any suspected counterfeits identified from visual checks, can be brought into more extensive testing processes. The next step for these more advanced parts is some electrical testing.
Simpler components like passives can be tested with a multimeter or LCR meter just to check that component values are authentic. Some components will exhibit specific behavior when powered on or when placed into a test circuit. If you look in the datasheets for some ASICs, you may see a recommended test circuit and expected outputs from the component.
Example test circuit and expected waveforms for a Texas Instruments power switch (part number TPS2020/21/22/23/24)
MCUs and other digital processors typically don’t have a specific test circuit, but they can be placed in a fixture and tested with an automated test program. A test board would need to be created and one of the MCUs would need to be placed onto the test fixture. The component could then be flashed with firmware and a test script could be run on the device while monitoring I/Os.
For some components, this kind of automated testing is intractable. Consider a large FPGA; these devices could have hundreds of pins on a BGA package, and any test board used for these parts would have to be very sophisticated. These components could also be very expensive, and it is difficult to justify sacrificing multiples of these components for quality control. More advanced inspection of these components is more cost effective and requires less time to authenticate a component.
The most common non-destructive testing method for authenticating electronic components is X-ray inspection. Those who understand PCB assembly with BGAs will know that these components are inspected for assembly defects using X-ray imaging. These same systems can be used to inspect components for authenticity.
When you look at an X-ray image of an integrated circuit at a controlled depth, what exactly should you be looking for? Generally, you will see an image of the die, leadframe, bonding wires, or any other components embedded in the package . An example of a damaged component is shown below.
Damaged component being inspected in an X-ray image. [Source]
X-ray imaging allows immediate inspection of the die inside the package and can eliminate two common forms of counterfeiting:
- Selling damaged components that will likely be non-functional in an assembly
- Selling components with the die removed from the package
The presence of a die, intact lead frame and bond wires, and no other damage to the component can be quickly qualified from a visual inspection of the die in an X-ray image.
If a die is present, how can it be verified to be authentic? This is where you would want to compare the shape and lead frame arrangement around the die to another component that is known to be authentic. Some components have unique die shape and embedded component arrangement, and the arrangements in a suspect component can be compared to the authentic component in an X-ray image.
Counterfeit Parts in an Assembly
One of the worst cases of counterfeiting might not come from brokers, but instead from a PCB assembly house. If you are consigning components to an assembly house, the assembly house might use different parts than were supplied for the assembly job. They will then take your parts and resell them at a higher price. The replacement parts could be of lower quality (e.g., lower power rating), and of course they will come at a lower price. This is more likely to happen overseas where you will have a much more difficult time proving counterfeiting and obtaining compensation.
The parts assembled on the PCB should also be inspected if there is suspicion of fraud. There are a few signs of fraud in an assembled PCB:
- Assembled parts match the package, but markings were scrubbed
- Parts were encapsulated in epoxy, even if encapsulation was not requested
For low volume assembly orders, this is more likely to occur with integrated circuits. For higher volume orders, it could happen with reels of SMD parts, which will be much more difficult to inspect without desoldering the parts from the assembly.
An integrated circuit encapsulated in an epoxy compound. [Source: Anata]
Can You Avoid Counterfeits?
Authorized distributors of components get their stocks directly from component manufacturers, so they are not going to be the ones providing you with fake components. Brokers are the groups that are most likely to supply fake components for a PCBA. Taking some caution before ordering from brokers and implementing some qualification practices are the best ways to avoid counterfeits.
Finally, if you must rely on brokers and want to speed up test and inspection, consider building out test lab capabilities for your component orders. Some of the inspections listed above can be semi-automated through the use of computer vision systems and custom test fixtures. If you’re an OEM consigning components for high-volume manufacturing orders, or if you’re an EMS company, the additional investment provides insurance that assemblies will be functional and will not fail early.
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