A counterfeit semiconductor is a component that has been remarked or black-topped, so its marking no longer reflects what is inside. In aerospace and defence, where a single faulty part can put a system at risk, catching these components before they reach a board is essential. Force Technologies Applications Manager Ben Savage recently sat down with Eder, our Quality Manager to go into more detail as poart of our latest Tech Talk. This article is a result of what we learnt and hopefully will help you learn more about counterfeit semiconductors and be able to identify them.
What is a counterfeit semiconductor?
A counterfeit semiconductor is a remarked or black-topped component. A counterfeiter removes the original marking and applies a new one to change the part’s speed rating, temperature rating or qualification level, then sells it as a different or more expensive device.
Why are counterfeit chips so hard to spot?
Counterfeit chips are hard to spot because semiconductor packages are made to industry-standard dimensions. A 28-pin DIP from one manufacturer looks almost identical to a 28-pin DIP from another, and plastic packages are nearly indistinguishable by eye. Without advanced detection, a remarked part will not be caught until it is on a board and causing problems.
How are counterfeit semiconductors detected?
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Counterfeit semiconductors are detected through a sequence of physical and electrical tests set out in the AS6081 and AS6171 standards. The main checks are:
- Visual and dimensional inspection against the original drawing, confirming the component’s thickness, width, height and length.
- Chemical testing of the top surface, using strong acids to detect a black-top epoxy layer applied over the original marking.
- X-ray inspection to check uniformity across a batch and examine the internal lead frame, structure and die size.
- Decapsulation of a small sample, usually three pieces, removing the lid to inspect the die. Most OEM dies carry a logo or marking tied to the part number, which acts as an authentication check.
- Electrical testing, which AS6171 includes as DC, or a combination of DC and AC, even at its moderate level.
The clearest sign of a counterfeit is sanding marks, where the top of the component has been sanded down, material removed, new material applied and a fresh marking added over the top.
How is the level of testing decided?
The level of testing is decided by risk, which AS6171 defines within the standard, and the customer sets the risk level for their application. The standard scales from low through moderate to high risk.
Risk level
What it adds
Moderate
AS6081 inspection plus added electrical testing. The level most of the industry uses.
High
Adds burn-in, infant mortality testing and destructive testing, for critical applications such as aerospace.
Why does this matter for aerospace and defence?
A counterfeit component that reaches the supply chain can be dangerous in service, for example in an aircraft, which is why approved suppliers and rigorous incoming checks matter. In practice, genuine counterfeits are rare where these controls are in place. Over 40 years at Force Technologies, most flagged parts have turned out to be byproduct issues such as heavily oxidised leads or slightly out-of-spec dimensions caused by poor manufacturer documentation, not deliberate counterfeiting.
Force Technologies, have unrivalled experience in this area and are currently growing to be able to support more and more requests for testing and quality. If you think you have an issue, we can help, get in otuch with us via our contact form or pick up the phone. One of our team will be happy to get discussions going.