Using X-ray to crack the case of the counterfeit components
11 March 2011
Finding counterfeit parts is no easy task, but a strategy involving both visual and x-ray inspection will catch most of the fakes.
The first time a component distributor called Steve Zweig, vice-president of sales for Glenbrook Technologies, to ask about using the company's x-ray inspection equipment to detect counterfeit components, Zweig thought it was an isolated incident. Little did he realise that, four years later, the problem would have grown to such epidemic proportions that he'd embark on an investigation, going directly to the source and purchasing components from a Chinese market, then subjecting them to visual and x-ray inspection to discover what each technique would reveal.
Both the U.S. Department of Homeland Security and the U.S. Chamber of Commerce have reported that the incidence of counterfeit components has increased dramatically over the past decade, continuing right through the global economic slowdown. One estimate values the worldwide market for counterfeit electronics at up to $10 billion annually and names China, particularly the Shenzhen area, as the source of approximately 70 percent of those counterfeits.
The issue even attracted the interest of television’s Sixty Minutes. The program aired a segment highlighting two areas of concern: the potential economic cost to manufacturers who use counterfeit parts unwittingly and have to deal with product failures, as well as the health hazards associated with workers’ handling toxic materials and the impact of their improper disposal on the environment.
While the ideal solution would be to use only parts from Original Component Manufacturers, this is not always feasible, especially if the part is in short supply or is no longer manufactured. On the open market, parts are sourced through electronic component distributors, brokers or resellers — of which there are thousands in the U.S. alone.
“Since the counterfeit parts mix openly with other products, it doesn’t take long for them to slip into the inventory of even reputable firms,” Zweig explained. And many assemblers look for the lowest bids, even for critical applications such as military or commercial aircraft. It is in just such instances that counterfeit parts can be introduced into the supply chain.
Zweig’s interest in the counterfeit issue grew as component distributors began purchasing and using Glenbrook’s x-ray inspection equipment to build image libraries of known good parts against which they could verify images of incoming parts that have shown a history of being counterfeited. Glenbrook’s customers range in size from large firms that maintain more than 100,000 line items in stock and make thousands of component sales each month to hundreds of small companies, each employing fewer than 15 people.
Whether they are large, small or mid-size, all distributors share one concern: verifying the authenticity of the components they buy and sell is critical to maintaining customer bases that include Fortune 500 firms in the high-tech, military and medical sectors. No company wants to develop a reputation for passing on counterfeit parts, even unwittingly. Yet, industry-wide, relatively few distributors are using what appear to be all the necessary inspection techniques to identify counterfeits.
Many distributors rely on only two verification steps: checking the components’ documentation and conducting visual inspection, sometimes with minimal magnification. Some companies also select sample parts for decapsulation, a destructive technique, to inspect the internal die.
“I’ve visited some very large component distributors that did not use greater than 5x magnification,” Zweig said. “Yet many of the smaller distributors were using up to 1000x magnification.” A number of courses are offered in visual inspection of components, he notes, and they are quite comprehensive. One offered by the IDEA (Independent Distributors of Electronics Association) provides attendees with a hefty volume of reference images.
But without sufficient magnification, verification of questionable components cannot be assured. “With the use of a metallurgical microscope, generally up to 1000x, the inspector can see the entire die with its markings and logo as well as the bond wires,” Zweig explains.
Adding x-ray inspection to the process enables the inspector to compare the components’ internal features non-destructively, within a lot and with known good samples. Ideally, the distributor builds a library of part numbers and compares each new x-ray image to a known good image. Among the problems that can be identified through x-ray inspection are broken or damaged wire bonds, totally missing internal features, variations in die size and sometimes parts that are marked backwards.
The x-ray images can be used to demonstrate to a component provider why parts are being rejected, and to verify to the distributor’s customer that the parts are authentic. Assemblers may even require x-ray images along with written documentation. Indeed, the more assemblers insist on such verification, the more difficult it will be for counterfeit components to make their way into the distribution channel and ultimately into cell phones, video games, aerospace instruments or medical devices.
How do these counterfeit parts make their way into the inventories of reputable companies? And how can they be identified before being assembled into everything from consumer electronics to critical military or medical devices? Zweig decided to track the suspects back to their source to see how easily counterfeit or bad product can be acquired and circulated into the component distributor channel.
With the aid of several Glenbrook customers, he developed a list of parts that have shown a history of being identified as counterfeit. He learned that recycled parts tend to come from the ever-increasing quantities of electronic scrap that provide a tremendous amount of raw material to counterfeiters, many of whom operate in the Shenzhen area of China.
“In these facilities,” Zweig reported, “board sorting can take place almost anywhere, in large warehouses or small shops. Workers remove parts from the boards with their bare hands or basic tools, with no protection from contamination and no ESD precautions.” As a result, parts that are labeled “recycled” are not always guaranteed to work properly. The sorting process involves nothing more than placing the parts into cups or jars. Generally, they are separated by package type and later by manufacturer or part number. At this point the refinishing or recycling process starts.
The parts are sanded to remove the original marking and then blacktopped and remarked. Blacktopping involves applying a black filler to the top surface of the part, then it may be marked with a different company name, logo and part number. An original Xilinx part may be remarked as a Motorola part. If the part is used in a critical application, the end result could be catastrophic.
“It used to be possible to identify blacktopping by rubbing the top of the part with a solvent,” said Zweig. “But newer blacktopping materials are proving more resistant to standard detection techniques. Clearly, counterfeiters are continuing to improve their techniques to prevent detection.” They also seem to have quick access to information regarding poplar part numbers, how to blacktop and repackage them, then insert them into distribution channels through the large number of huge electronic shopping marts devoted exclusively to selling components in the Shenzhen area.
Zweig’s next step in his detecting venture was to enlist the aid of an associate. Working with Glenbrook’s Hong Kong office, he dispatched one of the office’s Chinese engineers to the Shenzhen market with the list supplied by Glenbrook’s customers. At the market, components were marked as new or recycled, with the recycled parts priced as much as 80 percent less than the new parts. Glenbrook’s engineer bought five to ten of each lot of components, selecting both new and recycled parts on the list.
The investigation then entered its forensic stage, with the evidence subjected to a variety of inspection techniques. First, Zweig used Glenbrook’s JewelBox 70T real-time x-ray inspection system, with up to 1,200x magnification, to inspect and capture images of each part. Then, because Glenbrook has less knowledge of the visual inspection process, he called on a distributor, Chase Components in New Smyrna Beach, Florida, for assistance. Chase, a Glenbrook customer, uses both x-ray and visual inspection as part of its extensive quality control process.
“They were very generous in sharing their expertise in visual inspection with us,” Zweig said. He traveled to their facility to conduct solvent tests for blacktopping, using two different solutions: 30 percent alcohol and 70 percent mineral spirits, and 25 percent alcohol and 75 percent acetone. Since newer blacktopping is resistant to the first solution, both techniques were used.
The study strongly emphasised the importance of experience in terms of visual inspection, knowing the correct techniques and current situation, as well as having the ability to use x-ray inspection to check components internally. While some defects can be spotted visually, others are not revealed until x-ray inspection provides an internal image.
It is only through the interaction of both techniques that a distributor can be assured of providing good components to its customer base — and assemblers can have greater confidence in the authenticity of the components they purchase. At the same time, it’s easy to see how such defective parts can be re-introduced into the distribution channel without any history of the results. “Good documentation and thorough inspection is absolutely critical to monitoring and, hopefully, reducing the problems posed by counterfeit electronic components,” Zweig concluded.
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