When I worked as an engineer for a manufacturer of semiconductor production equipment, purchasing would often ask us to provide second sources for various ICs. For those parts that had second sources, we would test the parts to verify that second-source parts met expected specs before deciding if the parts would work for us.
Parts such as 74xxxx series logic devices and common op amps have long had such second sources available from authorized manufacturers and distributors. Fake parts—those removed from scrap boards and sold as new—have been a common problem for many years. In recent years, however, a new class of fakes—cloned parts—has appeared in the supply chain. In some cases, these clones have been found to have some specs that are better than those of authentic parts.
On December 12, Tom Sharpe, VP of SMT Corp., spoke to a gathering of the Boston, New Hampshire, and Providence chapters of the IEEE Reliability Society about cloned parts. Sharpe gave an even more detailed presentation to the National Security Agency (NSA) the previous week.
Sharpe opened by showing what SMT was seeing in 2012 and followed by what's coming out of China today. The presentation was based on tests performed at SMTs labs. SMT is a distributor specializing in obsolete parts, stocking nearly 500 million parts, much of which is sold into the defense sector.
"We saw first cloned devices appear in 2012, said Sharpe, "starting with the MAX232. At that time, we had only heard about cloned parts and they were slipping into the supply chain undetected. That year, SMT found nineteen different cloned parts affecting eight original component manufacturers (OCMs), all major manufacturers. Today, we see over 150 cloned parts representing 31 OCMs."
Sharpe clarified the difference between a clone and what was originally called a counterfeit part. "Prior to 2012, we were seeing reworked parts that had been removed from e-waste circuit boards being sold as new, but they were generally authentic parts (EBN's sister publication EDN reported on such activities in 2011). A clone, however, is made entirely by the counterfeiter, from the ground up. The counterfeiter has complete control of the cloned parts design and manufacture. "Many IC companies are fabless," he continued. "They may not even be aware that the fabs making their parts are also making clones." Sharpe added that he was not aware of any "ghost fabs" making cloned parts.
In 2012, SMT started seeing what Sharpe called "Functional die emulation" where the cloned part functioned well at room temperature. Upon investigation, SMT found that the die inside the package was completely different from that of an authentic device (Figure 1).
Figure 1. A cloned device (right) had a completely different die than an authentic device, yet was functionally equivalent. Click image to enlarge.
While functional equivalents are one thing, Sharpe noted that later in 2012, SMT began to see cloned parts where even the mask of the authentic part had been copied. "They even did a one-third die shrink," he noted.