The economic impact of counterfeit goods in our society is staggering. The world trade of counterfeit goods is estimated at over $600 billion dollars annually1. As consumers, we often buy counterfeit goods in the form of clothing, handbags, watches, golf clubs etc, either willingly or naively since we are not particularly concerned with the long term quality of such items.
No one wants to buy counterfeit food or medication, yet we often purchase those from uncontrolled sources, becoming targets for unscrupulous sellers of less-than-perfect products. Counterfeit cereal is so widespread that Kellogg's has developed a hi-tech method to stamp out imitations by laser branding individual flakes in Corn Flakes cereal with the company logo2. If melamine can find its way in brand name baby formula or pet food, what lurks in deliberately counterfeit food products?
The purchase of electronic components is a business-to-business transaction, since few of us have needs to acquire reels of thousands of integrated circuits, resistors or capacitors in our daily lives. Business transactions have checks and balances regarding quality, such as procurement specifications, ISO certifications, terms and conditions. Yet counterfeit electronic components proliferate within the supply chain. As reported by IHS, there has been "a 140% increase of counterfeit incidents in three years, but that's only what the U.S. Department of Commerce has been able to document. The problem is unquestionably bigger than this. That figure only accounts for the incidents reported, and the majority of incidents go unreported."
Who falls prey to counterfeit components?
Why would you be a target for counterfeit components? Do you have a need for obsolete components, a need for leaded components in a lead-free world, a need for lead-free older components, for repairs or for special applications? Caveat emptor! (Let the buyer beware). What can you do to ensure that counterfeits do not find their way into your product?
Although counterfeiters get better all the time, when the intention is to deceive, quality monitoring is not too strict and there are often tell-tales signs to look for. Scratches, poor markings and evidence of prior use are often present and easily detectable to the naked eye or a low power microscope. Such defects are not to be ignored. If you do dismiss these indications, you may be the next victim of a sly forger.
Not every counterfeit component is a clone. In our experience at MuAnalysis, we have seen only a few cloned ICs but several instances of cloned capacitors and some cloned diodes. Many counterfeit parts are not clones, they are genuine older parts, sometimes used, sometimes known to be defective, that have been rebranded, often cleaned of lead plating, and sold as new parts. The uniformity of manufacturing expected in a date or lot code is absent when parts from various dates and sources are grouped together.
Counterfeits are often re-branded
A common counterfeit is a BGA chip, originally leaded, now rebranded and sold as lead-free. Sometimes the counterfeiter will not even bother to replace the balls. It's easy to spot lead balls, if you know what to look for, and if you bother to look. If your lead-free BGA has shiny balls, a check with an X-Ray Fluorescence (XRF) instrument is called for. If the balls have been replaced, it could have been done well, or very badly. Remember that this seller is trying to deceive you. Have ESD precautions been adhered to? Most likely there will be more than one date code in the "lot". Were the parts fully functional before reballing? Were they whole? Were they new parts or have they been reclaimed from recycled boards? Assuming that there are no obvious defects, you have a part with lead-free balls in-hand that was never meant to be. It is probably not RoHS compliant. It has received two additional reflow cycles already, one to remove the lead balls and one to attach the lead-free balls. The die attach was not designed for the higher temperatures of lead free soldering and its glass transition temperature has possibly been exceeded already. The good parts in the lot may work, for a while.
The worst case scenario is a part that looks brand new. It can be from a defective wafer batch, targeted for destruction, but that somehow survived and was assembled as a genuine part. It can be from a reclaimed second-hand part. The reclaiming "plant" is certainly not ISO registered. It's likely to be a bonfire by the side of the dump. The process of refurbishing second-hand parts is called black topping and consists of applying a thin coat of new encapsulant on an old part. Only certain chemical etches can reveal that the part has been black topped.
X-Ray may not detect anything unusual
What lies inside the new exterior is a defective die. X-Ray may not detect anything unusual, acoustic microscopy might detect a reclaimed part, if the die has cracked or the part is badly delaminated. Parts assembled from bad wafers look pristine if the counterfeiter is skilled. Opening the part and looking at the die may not reveal anything amiss unless the defects are gross. We have seen a part that was missing a mask level. If a reference part had not been available the deception would not have been detected.
Passive components are easier to clone than ICs. Cloned capacitors are unfortunately very common. Usually the electrical performance of the cloned components does not match the datasheet. Bench testing a few components from the lot is quick and simple. If the mean value of any parameter is off, including the exterior dimensions, further analysis may be desirable. The consequence of installing a counterfeit capacitor or resistor in a product is a shorter than expected lifetime which may result, among other things, in tarnishing of the product's and company's reputations. Other easy to clone items include diodes, resistors and hybrids.
Some parts look suspicious and are easy to spot. Most parts are small, but what is missed by the naked eye is obvious under a microscope. If the package thickness is less than specified, this is a tell-tale sign of rebranding. Pay attention to cleanliness, fonts and logos. Do not ignore the subtle signs. If the quality looks questionable, it probably is.
X-Ray Fluorescence can detect residual tin-lead plating or lead balls. If the part is sold as lead-free, you have a counterfeit in-hand. X-Ray imaging can easily pick up differences in die size or configuration, and detects die attach voiding, which is never a good thing, particularly if the part has high power consumption. Acoustic microscopy reveals previous use by detecting delamination or cracked die. Mask revisions and die level defects, which can affect functionality, are much harder to spot.
New standards aim to mitigate problem
Standards such as AS5553 and AS6081 are being developed to mitigate the proliferation of counterfeit components by defining practices and methods related to parts management, supplier management, procurement, inspection, test/evaluation and response strategies when suspected or confirmed counterfeit parts are discovered.3
Tests are available to spot counterfeits, some you can do yourself, some that require specialized equipment. However tests are useless if you are not aware that you are a target and ignore the evidence before your eyes. Be vigilant and avoid falling into the counterfeit trap.