X-Ray Inspection for Counterfeits: When You Need It (and When You Don’t)

When people talk about counterfeits, they often picture fake watches and handbags. In practice, the electronics industry uses the term in a broader way. We consider a counterfeit to be any part that is not new and original.

• New - the device has never been attached to a board or powered up, and has never been altered to appear new by, for example, re-marking, lead plating, chemical cleaning.
• Original - means the device truly came from the manufacturer printed on the package, and on the part, and contains the correct die for that part number and lot.

So the counterfeit inspection process is all about deciding if a part is new & original.

Short answer: probably not you.

Most hardware teams do not run counterfeit inspections themselves. Contract manufacturers usually do not either. In practice, inspections usually happen in one of two places.

Broker-operated labs. Many component brokers run their own inspection labs. If you buy parts through a broker, they may perform some or all of the inspection steps before the parts ever reach you. That can be extremely useful, but it also means the fox is guarding the chicken coop. Nothing inherently wrong with that. It just means you need to pay a little more attention to what you're committing to, in particular, the acceptance criteria.

Independent third-party labs. Some buyers prefer to send the parts directly to an outside inspection lab. These companies specialize in counterfeit detection and failure analysis. They are not involved in the sale of the components, so their reports tend to be viewed as more neutral.

Cofactr offers a unique third option. Counterfeit inspection is conducted on-site at Cofactr warehouses, giving you the equivalent of in-house inspection expertise.

The lab runs the tests. You make the call.

Inspection reports can be very clear sometimes. Other times, it’s less black-and-white. Maybe the internal structure looks a little different than expected. Maybe the label format looks unusual, but not obviously wrong. Maybe the surface finish raises an eyebrow, but nothing outright fails. This happens more often than people expect.

In those situations, the inspection lab will usually give an opinion in the report. Most buyers follow that recommendation. The lab does this work all day and they have seen a lot of parts.

Still, the final acceptance decision belongs to the buyer. You are the one deciding whether the level of risk makes sense for your product. Some buyers walk away from anything questionable. Others may accept a small amount of uncertainty if the parts are difficult to source or the application risk is low.

Pro Tip: Watch the purchase terms when buying from a broker. Specify “new & original” or “new & original as verified by [you’re preferred lab]”. If your source resists these terms, that’s a huge red flag.

Most inspection labs follow a standard called AS6081 when inspecting electronic components for counterfeits. Think of it as a structured inspection stack. Each step gathers a different kind of evidence about whether the parts are truly new and original.

The tests start simple and inexpensive, then gradually move toward more detailed or destructive analysis. If a lot clearly fails early in the process, the lab usually stops there because the answer is already clear.

Here’s a simplified version of the AS6081 inspection flow and what each step is primarily inspecting for.

Notice the first steps are external tests to verify new. The next steps are internal tests to verify the original.

Sometimes these tests produce clear pass or fail results. Other times the outcome depends on interpretation by the technician reviewing the evidence.

Think of it this way. First evaluate for new, it’s cheap and (mostly) non-destructive. If obviously not new, stop testing and reject the parts. Then, if the part is new, evaluate for original.

Let’s look quickly at the inspections for new. Inspectors look for answers to these three questions:

1. Is the documentation satisfactory?
2. Were the external visual inspection (EVI) results satisfactory?
3. Was the marking permanency test satisfactory?

If the answer to all three is clearly yes, using X-ray to inspect for original may not be necessary. If any of them raise questions, X-ray is the next step.

1. Is the Documentation Satisfactory?

The first question is whether the paperwork and labeling associated with the lot make sense.

Sometimes a shipment will include a Certificate of Conformance traceable to an authorized distributor. In this relatively rare instance, you may want to just accept the parts and not invest in further inspection.

More commonly, document inspection focuses on the labels on the shipment itself. Manufacturers tend to use very consistent labeling formats. Font styles, barcode formats, and lot code structures are often specific to each manufacturer.

The inspector checks whether the labeling appears legitimate and whether all labels agree with each other. The outer box label should match the labels on sealed moisture barrier bags, reels, or trays inside the shipment.

Here’s a breakdown of Texas Instruments labels:

Here’s an example of subtly mis-matching labels:

Can you spot the differences? Look carefully at the Lot Number, and at the BOX X OF 21. These are discrepancies a factory wouldn’t make.

When these labels don’t match known manufacturer practices or conflict with each other, that inconsistency alone can trigger rejection. More often, it is a red flag justifying further investigation.

Why just a red flag? Because manufacturer label practices can vary between manufacturing sites and they can change. Keeping track is quite difficult.

Pro Tip: In practice, most labs place relatively little emphasis on labeling as more than a contributing data point. If you really want labels verified, best practice is to provide an image of a known good label.

2. Were the External Visual Inspection (EVI) Results Satisfactory?

External visual inspection, often called EVI, looks at the physical condition of the component under magnification.

Inspectors typically examine parts under 10x to 90x magnification. They look for signs that the part may have been removed from a board and recycled, and/or the part has been re-marked. Here are common EVI inspections:

Part Marking

Part on left is original B grade, part on right re-marked as A grade. Re-marking is often done after blacktopping (discussed below) to make the part more valuable by marking as a more expensive version or refreshing the date code.

In this example the Pin 1 marking on the left is a dimple, on the right it is screen printed. This can be the result of blacktopping.

Exposed copper on leads

This is a big one. At the factory copper leads are plated, often with tin, then trimmed to final length. This results in exposed copper easily visible under magnification. If a part is later replated to hide signs of prior use, the exposed copper is covered over. Failing this test is an almost certain reason for rejection.

Stress marks from forming

At the factory leads are formed after plating, leaving obvious stress marks visible under magnification. Re-plating covers these stress marks, another very obvious sign the parts are not new.

3. Was the Marking Permanency Test Satisfactory?

Marking permanency testing evaluates whether the top marking on the device is original or has been reapplied, commonly called blacktopping.

When the coating or markings smear, fade, or reveal underlying text during these tests, the part is almost certainly remarked and will be rejected as not new.

Scrape Test

Also called a mechanical test, this involves scraping the top of a part, usually a corner, with an Exacto knife to see if the top coating can be easily scraped off, and if it reveals a covered layer. This test is very common, but relies heavily on the skill and judgement of the operator so is generally not considered definitive proof the part is not new.

Chemical Test

This test involves using chemical solvents to attempt to dissolve blacktopping. A lab might start with acetone, but the more serious chemical test is called a Heated Chemical Test (HCT) using Dynasolve750 or N-Methyl-2-Pyrrolidinone heated to ~100C for 5-10 minutes.

XRF Testing

In the counterfeit detection context, XRF is primarily used to detect the presence of lead. If a part is labeled lead-free and XRF detects lead, it has almost certainly been replated and is therefore not new.

There are two points of view on XRF testing. It is very fast (seconds) but the equipment costs $20,000 to $120,000 and almost never rejects a part that has passed the prior tests. While it is common in labs because labs usually do more than counterfeit detection, deploying solely for counterfeit detection is not really necessary.

Summary

If a part clearly fails any of these tests and is determined to be clearly not new, inspection usually stops and the parts are rejected.

If the parts are unequivocally new, most labs prefer to conduct some tests for originality as outlined in AS6081. Do you really need to? Not really. The chances of a part passing this gauntlet of tests with flying colors and yet containing a non-original die are vanishingly small.

But it is very common for the newness tests to have some uncertainty, making additional testing necessary. The practical, real-world decision tree looks like this:

• Definitely not new: stop testing and reject the parts.
• Definitely new: can stop and accept the parts, or test for original to provide additional assurance at relatively low cost.
• Uncertain: must proceed to testing for original

X-ray inspection is the gateway to validating originality. Why? Because it is inexpensive (usually around $50) and non-destructive.

X‑ray inspection produces an image of the internal structure of a component without cutting it open. Dense materials absorb more radiation and appear darker. Less dense materials appear lighter. That contrast reveals features inside the package.

Is X-ray inspection a definitive test for originality? Well, it depends.

The Golden Sample

The most powerful use of X‑ray inspection is direct comparison against a known authentic component. Labs aren’t going to find known authentic parts themselves, too much liability. So you need to provide one, we call this the ‘golden sample’.

When a lab has a golden sample, the inspector can compare the internal structure of the inspected device against the known-good reference. This comparison focuses on construction details that tend to remain consistent across production.

Common comparison points include:

• Die size and shape
• Die placement inside the package
• Bond wire count and routing pattern
• Lead frame geometry

Even small differences can be meaningful. If the golden sample shows a specific die size and bond wire layout, and the suspect part contains a smaller die or a completely different wire pattern, that inconsistency is a strong signal that the device may not be original.

In this example, notice the differences in the lead frame, geometry, and wire bonds. The fake part is clearly not original and should be rejected.

If a golden sample is provided and the evaluated parts clearly match the golden sample, it is reasonable to consider the parts original.

When No Golden Sample Is Available

Very often no golden sample is provided to the lab. In that situation, X‑ray analysis focuses less on comparison and more on looking for anomalies inside the component.

Inspectors examine the internal structure of the package to identify problems such as:

• Inconsistant internal structure
• Voids inside the encapsulation
• Die that appears unusually small for the package
• Abnormal die placement
• Broken or missing bond wires
• Missing die

These observations do not always prove that a component is not original, but they can reveal internal conditions that would be highly unusual for a legitimate device.

These two parts were presented as the same part from the same lot. Without knowing if either one is original, clearly one of them is wrong, and the lot should be rejected as not original.

Evidence of Prior Use or Damage

Some suspect parts started life as used components pulled from scrap circuit boards. X‑ray can sometimes reveal internal evidence of prior stress such as cracked die, broken bond wires, or displaced internal structures. While possible, in practice this finding is rare.

By now, it should be clear X‑ray inspection is powerful, but it answers internal structural questions related to originality only. X-ray can’t tell you anything about the external features of the part, and there are some internal features it cannot identify either.

It Cannot Confirm the Silicon Identity

Two dies can have identical shapes but contain completely different circuitry. X‑ray shows geometry, not transistor layouts.

If the wrong chip was packaged in the correct housing, X‑ray alone will not detect it. Labs typically resolve that uncertainty with electrical testing or decapsulation.

It Cannot Verify Markings on the Die

Manufacturers often place logos or mask markings on the silicon surface. Those markings help confirm origin.

X‑ray cannot read them because the technique shows density differences, not surface text. Decapsulation is required if that level of verification is needed.

Given those limitations, you might wonder why X‑ray inspection appears in nearly every counterfeit detection workflow.

The reasons are efficiency, cost, and non-destructiveness.

A single X‑ray scan can quickly expose problems that would otherwise require destructive analysis to discover. Missing dies, incorrect die sizes, or abnormal wire patterns stand out immediately. When those problems appear, the inspection process can stop early.

That saves time, money, and good components from unnecessary destruction.

Read More: Counterfeit Electronic Components

When deciding whether X‑ray inspection is worth the cost, focus on the questions you are trying to answer.

X‑ray is well-suited for questions like:

• Does this package actually contain a die?
• Does the die size match known authentic samples?
• Do the bond wires follow the expected pattern?
• Is the internal structure consistent with the manufacturer’s design?

X‑ray is not suited for questions like:

• Is the silicon functionally correct?
• Is the lead plating composition legitimate?
• Were the external markings altered?

Those require electrical testing, XRF analysis, or decapsulation.

X‑ray inspection is a highly effective and efficient checkpoint in counterfeit component detection. When combined with a golden sample, it provides near-certain verification of originality at low cost and without destroying the test part.

Ready to let Cofactr handle sourcing, negotiations, storage, kitting, and delivery while your team focuses on building products? It’s free to get started with Cofactr today.

What is counterfeit inspection in electronics?

Counterfeit inspection determines whether a component is truly new and original, meaning unused, unaltered, and manufactured by the stated source with the correct internal die and specifications.

How to decide if X-ray inspection is needed?

Use X-ray inspection when earlier tests raise uncertainty about a component’s originality. If documentation, visual inspection, and marking tests are clearly satisfactory, X-ray may not be necessary.

Why does X-ray inspection matter in counterfeit detection?

X-ray inspection reveals internal structures like die size and wire bonding patterns, helping identify inconsistencies or anomalies quickly without destroying the component, saving time and reducing unnecessary testing costs.

Can I rely only on X-ray inspection to verify authenticity?

No, X-ray cannot confirm silicon functionality or exact chip identity. It only shows structural details, so electrical testing or decapsulation may be required for complete verification.

What is a golden sample in X-ray inspection?

A golden sample is a verified authentic component used as a reference. Comparing suspect parts against it helps inspectors detect subtle structural differences that may indicate counterfeit or non-original devices.

Who performs counterfeit inspections?

Inspections are typically conducted by broker-operated labs, independent third-party labs, or specialized providers. Most hardware teams rely on external experts rather than performing inspections internally.

When does the inspection process stop early?

Inspection stops early when a component clearly fails initial “newness” tests, such as visual inspection or marking permanency, since further testing becomes unnecessary once non-new status is confirmed.

Is it safe to accept parts without full inspection?

It can be acceptable if parts have strong documentation, like traceable certificates from authorized distributors. However, risk tolerance and application criticality should guide whether additional inspection is needed.

What are the best indicators a part is not new?

Signs include replated leads, missing stress marks, exposed copper inconsistencies, or altered markings. These often indicate prior use, rework, or remarking, leading to likely rejection.

Do I always need advanced tests like decapsulation?

No, advanced tests are only necessary when uncertainty remains after earlier inspections. Most counterfeit detection decisions are made using simpler, non-destructive methods before escalating to destructive analysis.