Saturday, October 1, 2016
VOLUME -23 NUMBER 12
Publication Date: 12/1/2008
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Archive >  December 2008 Issue >  Special Feature: Test and Measurement > 

Guarding Against Counterfeit Components
Optical image of the termination of good and counterfeit ultra-fast diodes, and x-ray images of aluminum wire connections at the leg of the good and counterfeit ultra-fast diodes.

There are counterfeit components out there — lots of them — and every one of them is booby-trapped to ruin somebody's otherwise well-designed product. With electronic components becoming more expensive, obsolete, scarce or hard to find,this unfortunate reality is being exploited by unscrupulous individuals who deal in bogus components. And they can creep into your supply chain no matter what.

How does this happen? Even though your supply chain is managed very carefully, the realities of providing customers with on-time delivery, combined with the ease of internet searches, can lead you or your suppliers into the "gray" market. Counterfeiting issues are not just limited to expensive or exotic components, where relatively high unit cost would appear to be highly attractive to the criminal element. Counterfeiting often exists for long lead-time or obsolete devices with unit values below $10. These low-value devices are arguably far more dangerous to the production quality of board level assemblers, with tremendous risk and negative impact on their business reputation, in addition to the cost of identifying assembly problems and doing the follow-on rework and repair.

As with every aspect of supply and demand, the opportunity for a counterfeiter increases as the need for a given item increases. The reasons for counterfeiting in the PC board assembly market include limited availability of specialty components, general supply shortages for standard devices, sourcing of obsolete or end-of-life components, sole-sourced components with long lead times, limited availability of new components for a new product introduction (NPI) build, pressure from customers to decrease time to market, or the necessity of purchasing components from the gray market to satisfy customer demands.

Although it is always best practice to obtain components from trusted and reputable sources, the reality of these day-to-day market pressures means that trusted suppliers cannot always provide what is needed in a timely fashion. Under these conditions the PC board assembler is often forced to turn to the web to source what is needed. Unfortunately, this is what counterfeiters are waiting for. When you have no choice but to look outside the known supply chain, suspicion must become the watchword. This is the case even when obtaining gray market items from regular suppliers. With expensive components of a few hundred dollars each, their high value calls for extra vigilance. It is quite normal to run additional tests and quality assurance steps to guarantee the quality of these items before they are used. Unfortunately, much lower value devices are also being counterfeited, items that have unit values of $10 or less.

Lower-Cost Counterfeits
With such inexpensive devices being counterfeited, these can be the most dangerous to your business and your company's reputation. This is because the crafty counterfeiter can supply a small quantity of genuine items for quality verification or sometimes include a small number of real components at the beginning of a reel. Reel-based SMT components are not always checked prior to placement, so a simple trick is for the counterfeiter to re-label the entire reel. Since many plastic devices are moisture sensitive, if the items arrive in a moisture-proof bag, most PC board assemblers do not check inside the package for fear of exposing the components to moisture. As a result, as long as the external label has the correct information, then this is often sufficient to accept the counterfeit components into production.

Even after analytical checks on a few components at the beginning of a reel appear to be good, it is generally not practical to check additional samples further within every reel at incoming inspection — especially when the unit cost is low. Because of this, inexpensive counterfeit components can readily get onto the production floor. The same is true for items purchased through the legitimate supply chain, since a supplier cannot always guarantee checking every low-value item they obtain on your behalf through the gray market without dramatically increasing costs. As before, when the component unit value is small, it does not raise suspicion. In many cases the plastic molding and exterior markings of good and counterfeit components look very similar. Often a detailed optical examination can reveal a difference in the termination of a counterfeit item. Again because these components are less then $10 they often only merit a cursory inspection. However further x-ray inspection of these two items shows that in addition to the differences mentioned above, the aluminum wire count and bonding can also vary.

Because of the relatively low unit cost and the cost of verification, such low-value counterfeit components are the most difficult to detect once they enter into production. Once they are assembled onto a board the presence of a low-value counterfeit is not the first, or the easiest item, that is considered to be the root cause of a product failure.

Quick Visual Not Enough
With a quick visual inspection often being the main acceptance test for low-value components, especially without using a microscope, counterfeit components can easily pass since the serial number and other printed information appears to be correct. This is because it is relatively easy for a counterfeiter to "black top" or paint the device and re-print other markings over it.

The route from component manufacturer to PC board assembler is often very long and can go through many hands legitimately which means there are many opportunities for a counterfeiter to get fake devices into the system. A certificate of conformance is no guarantee because externally the counterfeit devices look like a real item and a swap could easily have been made at some point within the supply chain. It should be remembered that if the counterfeiter is capable of reprinting details on the devices themselves, then forging a certificate of conformance to pass visual inspection is also relatively easy.
X-ray image of good and counterfeit DAC showing variation inside two identical packages.


If everything appears to be correct on the outside of a device, then the question remains what opportunities are there for inspecting the inside of components. It is possible to remove the lid from some packages or to dissolve away the plastic molding compound from others. However, such tests are destructive and even if the tested components in a mixed batch are fine then they are unable to be used in production. With a mixed batch of items it is impossible to test every item. Therefore, non-destructive tests are required, ideally tests that are quick and simple to perform.

X-ray Inspection
With the use of a good quality digital x-ray inspection system that provides high magnification at oblique views and with large grayscale sensitivity, it is possible to quickly and easily non-destructively see inside the suspect packages. By taking images of known good samples that clearly indicate the correct wiring and sub-assembly alignment within the packages then production operators and incoming inspectors can quickly compare these to suspect devices. If all is well, then these items can be passed on for production use. However, if something is wrong, then not only have these counterfeits been prevented from contaminating production, but these tests provide a digital record when the devices are within their original packaging and without breaking any security seals. In this way, these suspect items can be rejected and compensation received from the supplier.

Other Inspection Techniques
X-ray fluorescence, or XRF, allows components to be checked non-destructively for their chemical composition, in particular detecting the presence of lead in what may have been supplied as a lead-free device. Infrared microscopy allows selected surfaces of die and bond sites to be examined without removing the molding compound and exposing the top surface of the die. This leaves the bond sites intact for possible electrical test but preparation of the component requires grinding so that access is available to the surface of the silicon die.
X-ray image of counterfeit device that has no die or wire bonding contained inside.


Solvent body softening, component de-lidding and jet or plasma etching can also be used to carefully remove the surface material of the component so that further optical examination can be performed against a known good component. However, a quick check with x-ray inspection can achieve the same results by exposing the insides of the good and counterfeit packages.

Therefore, x-ray inspection can non-destructively discriminate between good devices and counterfeit components without labor-intensive and time-consuming testing.

The presence of counterfeit components within the supply chain is a real issue. Unfortunately, they are not just being targeted at expensive devices but, more insidiously at low-value items as well. It is difficult to quantify how big a problem counterfeiting is, but it has been suggested its impact could be as much as $10 billion annually.

Adding x-ray inspection and other analytical techniques into acceptance procedures does require personnel, time and money. But if screening is not done, it can result in counterfeit components being used on production boards where the real cost of fixing the problem — repair, reputation and potential lost future business — can be enormous.

Contact: Dage Precision Industries, Inc., 48065 Fremont Blvd., Fremont, CA 94538-6541 510-683-3930 Web:
http://www.dage-group.com

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