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Fancy some fishy-chips? Just order one of these sensors: Research shines light on suspect component sources

(2020/07/14)


If you're looking for cheap electronic sensors, the internet has lots of possibilities, but buyer beware: they aren't always exactly legit.

Since 2018, Christian Petrich, a researcher with Northern Research Institute in Narvik, Norway, has purchased more than 1,000 temperature sensor chips from more than 70 vendors via eBay, AliExpress, and other e-commerce websites.

Most of the digital thermometers not obtained directly from the manufacturer or authorized distributors turned out to be illegitimate, he found. According to Petrich: "All of the probes bought on eBay and AliExpress contained counterfeit DS18B20 sensors, and almost all sensors bought on those two sites were counterfeit."

Petrich has been publishing his findings [1]via GitHub since October last year, and updated them recently with additional details about the [2]DS18B20 temperature sensor chip, originally made by Dallas Semiconductor and right now made by Maxim Integrated

[3]datasheet PDF

.

Petrich says at least four companies appear to offer clones of the DS18B20, three of which he identified as China-based GXCAS, UMW, and Beijing 7Q Technology (7Q-Tek). The Register emailed the three manufacturers for comment, though given the time difference in China we don't expect an immediate response. We'll assume, however, that they deny any wrongdoing and dispute the findings.

Maxim Integrated declined to comment.

Among the sensor chips analyzed, Petrich speculates some were stolen from the Maxim production line, some are less accurate than they should be in their temperature calculations, and some lack features like support for using parasitic power – using power even if a device is turned off.

Fake fuse: Bloke admits selling counterfeit chips for use in B-1 bomber, other US military gear [4]READ MORE

Beyond the ethical issues involved with buying and selling unauthorized goods, Petrich says, this matters because "some of the counterfeit sensors actually do not work in parasitic power mode, have a high noise level, temperature offset outside the advertised ±0.5 °C band, do not contain an EEPROM, have bugs and unspecified failure rates, or differ in another unknown manner from the specifications in the Maxim datasheet."

Counterfeit chips – made or obtained without authorization or scavenged from recycled electronics then rebranded for resale as if new – have been a concern for years, as matters of both law and safety. The issue received significant attention in 2012 when the US Senate Armed Services Committee published a report about [5]counterfeit parts from China that had been found in US military hardware.

Last year, the US-based Semiconductor Industry Association, in Congressional [6]testimony [PDF], cited the case of Rogelio Vasquez, sentenced to 46 months in prison last year following a [7]guilty plea for selling fake chips destined for US military systems, to underscore the importance of addressing the issue.

According to the SIA, member companies regularly try to get online marketplaces to remove counterfeit semiconductors. One such firm, the SIA claims, asks for about 2,000 counterfeit chip listings to be removed every month, mainly from Chinese websites like Alibaba, HC360, China.makepolo, and Taobao.

One of the problems, the SIA points out, is that credit for stopping fake goods tends to be measured in monetary value, which disincentivizes hunting for cheap fake chips that nonetheless might cause costly disasters by making devices fail.

"Unfortunately, [Customs and Border Protection] metrics that track the number of shipments or the dollar value of counterfeits seized, underestimate the impact that seizures of counterfeit semiconductors have on health, safety, and national security," the trade group said.

Another issue, the SIA said, is that counterfeit chips are often imported without any markings, which prevents them from being seized for trademark violation. The group wants such shipments brought to the attention of Homeland Security Investigations more frequently so the legitimacy of the unmarked chips can be better evaluated.

The trade group also argues for tighter government procurement – to keep known counterfeiters away from government procurement – and more cooperation between the US, Canada, and Mexico to intercept fake semiconductors. ®

Get our [8]Tech Resources



[1] https://github.com/cpetrich/counterfeit_DS18B20

[2] https://www.maximintegrated.com/en/products/sensors/DS18B20.html

[3] https://datasheets.maximintegrated.com/en/ds/DS18B20.pdf

[4] https://www.theregister.com/2019/02/05/us_counterfeit_chips/

[5] https://www.armed-services.senate.gov/press-releases/senate-armed-services-committee-releases-report-on-counterfeit-electronic-parts

[6] https://www.semiconductors.org/wp-content/uploads/2019/07/SIA-Comments-84-FR-32861-Counterfeiting.pdf

[7] https://www.theregister.com/2019/02/05/us_counterfeit_chips/

[8] https://whitepapers.theregister.com/

"mainly from Chinese websites"

Pascal Monett

Well the solution appears to be simple : stop sourcing from Chinese websites.

You can't get the counterfeit stuff off ? Who cares ? Don't use their websites, and leave the Chinese to buy sub-par, inaccurate hardware.

One day, the Chinese themselves will be fed up with the situation, and that's when things will move.

In the mean time, just don't buy on Chinese websites.

Re: "mainly from Chinese websites"

Manolo

So if I just want a simple sensor for a home weather station, I should buy an Adafruit BME280 for $20 + $15 shipping, instead of getting one from Banggood for $5.23 + $2.50 shipping? For that price difference, I'll take my chances.

Re: "mainly from Chinese websites"

Antron Argaiv

Depends, I suppose, on what your accuracy/reliability/price tradeoff equation looks like.

In my (admittedly limited) experience with direct-from-China traders, I've not been happy with the quality, and consider it money wasted. Tag is for what they do, usually sooner rather than later.

Re: "mainly from Chinese websites"

Doctor Syntax

But how do you know the non-Chinese website you bought from didn't buy from a Chinese website?

Indeed

Anonymous Coward

Even some of the (very) large official distribution channels have been caught out in the past (no idea how that happened though).

Re: Indeed

ChrisMarshallNY

Amazon has been dealing with this (maybe not as aggressively as some would like) for years.

Their fakes tend to be manufactured goods, but you can also buy components from them, like AliExpress.

Not counterfeit, not stolen

Anonymous Coward

Not a trademark violation (searched on DS18B20 trademark shows nothing, and no 'tm' on the chip next to its designation)

Not a copyright violation (the dies are different)

Not a patent violation (ancient chip).

When I search Aliexpress for "DS18B20 temperature probe" there are plenty, but none of them claim it is the Maxim chip and DS18B20 is as generic as NE555 is to timing chips, or AA is to batteries. Is an AA battery a counterfeit? I don't know who owns the trademark even.

As for this: "Among the sensor chips analyzed, Petrich speculates some were stolen from the Maxim production line, some are less accurate than they should be in their temperature calculations"

Seconds are seconds. Nobody is going to break into a factory and steal chips worth pennies, and happen to only steal the sub-par chips that just happen to be lower spec ones!

A more usual thing: they test them, the out of spec ones are sold as seconds, sold off to crappy cheap temperature probe makes who knock out $0.83 temperature probes. You then buy those probes and spend a lot of time checking they don't meet Maxim's spec and then writing a lot of words.

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