Counterfeit Components: A Practical Verification Routine

Counterfeit parts are rarely obvious fakes. Most are recycled, re-marked or out-of-spec units sold as new.

Visual inspection first. Check the laser marking against the datasheet font, look for sanding marks on the package top, and compare pin plating colour across the batch. Re-marked parts often have slightly different letter spacing.

X-ray fluorescence. A quick XRF scan of the pins detects the lead frame alloy. Genuine parts use consistent alloys; refurbished parts often show contamination.

Decapsulation. Destructive, but definitive. One unit per lot is enough to check the die marking and bond wires.

Electrical test at temperature. Room-temperature tests miss marginal parts. Test at the top of the operating range, where counterfeit and recycled parts fail first.

Supplier behaviour is a signal. A supplier who resists providing photos, date codes or a test report is telling you something. Good suppliers volunteer the information.