Counterfeit Component Detection and Avoidance

A counterfeit component is a part that is not what its label says. It can be a different grade of the same part, a rejected part that has been re-marked, a used part removed from a scrapped assembly, or a genuine die in a package that does not meet the specification. All four reach the line looking normal.

Why the Problem Persists

Counterfeiting follows scarcity and price. When a part is on allocation, an offered delivery that is better than the authorised lead time is a commercial signal rather than a technical one, and the pressure to accept it is strongest exactly when the risk is highest.

The detection methods work, and they work on the incoming inspection rather than on the production line. A part that is discovered after it has been built into an assembly costs the assembly as well as the part. Our component selection notes describe the part of the decision that happens before the order is placed.

What Can Be Checked Without Damage

Documentation, packaging, labelling and appearance are checked first, and they are the cheapest checks. A label with the wrong font, a reel with the wrong hub, a date code that is inconsistent with the lead time and a bag that has been resealed are all visible.

The physical checks that follow are marking permanence, X-ray of the internal construction, and a comparison of the lead finish with the specification. Neither requires the part to be destroyed, so they can be applied to a sample from every lot.

Marking and Blacktopping

Re-marking usually involves removing the original marking, which leaves a surface that is slightly different from the rest of the package. A solvent test, an abrasion test and a look at the surface under magnification all detect it, and the three together are more reliable than any one.

Marking that is in the wrong position, in the wrong font or inconsistent between parts in the same lot is the same signal. A genuine lot has a marking that is identical across the reel because it was applied by one machine in one pass.

Electrical and Functional Screening

Electrical testing detects the part that is a different grade or a different die, and it does not detect a used part that still meets its specification. Where the risk is used material, the test has to look for the evidence of previous use rather than for a functional difference.

Full parametric testing on a sample is expensive and it is the only way to catch a part that is close to the specification. Where the part is critical, the test is worth its cost; where it is not, the incoming checks are the reasonable limit. Our board quality notes describe how the sample result is recorded.

Evidence of Previous Use

A part that has been removed from an assembly carries solder on its terminations, a reflowed finish, a different lead coplanarity and often a package that has been through a thermal excursion. Under magnification the terminations show a finish that has been melted, which a new part does not.

The evidence is destroyed by any re-tinning, so the inspection has to happen before the part is handled. That is the reason the incoming inspection is a defined procedure rather than an experienced eye.

Supplier and Channel Controls

The most effective control is the channel. Buying from the manufacturer or from an authorised distributor removes most of the risk, and buying from an open market removes none of it. Where the open market has to be used, the risk is managed by testing rather than by trust.

Recording the channel for every lot makes the investigation possible later. Where a suspect part is found, the record identifies the other products that used the same lot. Our first pass yield notes describe how that traceability is used.

Quarantine and Response

A suspect lot is quarantined rather than returned, because the evidence is needed for the investigation. Returning it immediately removes the material that would show what the failure was.

The response to a confirmed counterfeit is a containment of everything from the same source, not only of the parts that failed. A supplier who re-marked one reel may have supplied several.

Records and Reporting

The record that matters is the lot, the channel, the checks that were applied and the result. Where a part is reported to a manufacturer or to an industry body, that record is the evidence that the report is based on.

Documenting the assumption is part of the purchasing work, and a short note on the specification of what will be accepted prevents a substitution that would otherwise arrive without a decision. Our fabrication notes describe how that specification is carried through to the build.

Process Control and Verification

Documenting the assumption is part of the design work, and a short note on the drawing prevents a question that would otherwise arrive a day later and cost a day of schedule. The process window is set by the narrowest step in the flow, so an improvement anywhere else shows up as margin rather than as yield until that step is addressed.

A short note on the drawing about handling, storage or packaging is often worth more than an extra decimal place on a tolerance.

FAQ

Is a cheaper part always a risk? No, and an unusually cheap price from an unauthorised source with a short lead time is the pattern that carries the risk.

Can X-ray detect a counterfeit? It detects a die that is the wrong size, a wire bond that is wrong or an internal construction that differs. It does not detect a used part that is otherwise correct.

What does gopcb provide for counterfeit avoidance? We provide channel controls with the source recorded per lot, incoming checks covering documentation and marking, X-ray and finish comparison on a sample, functional screening where the part is critical, quarantine with the evidence retained, and traceability to everything else from the same lot.