Abstract: Under the global semiconductor shortage market, fake chips began to circulate in the supply chain. The global chip shortage creates a golden window for fake chips to enter the market, brings quality risks to more electronic products, and damages the interests of machine manufacturers and end consumers.
Today, the author will show you what fake chips are there, and how are fake chips made? How should we distinguish between genuine and fake chips?
- MOS tube
Compared with other components, MOS tubes are easier to counterfeit. Different from common chips, general-purpose MOS, the appearance of the same package is not very different, but the MOS of the same model of different brands is still different, the same specifications and models, some standard test environments DS internal resistance hundreds of milliohms, some a few euros.
What the above-mentioned netizen got was not the model he needed to purchase, but the model with similar parameters and higher compatibility, which was marked with a genuine silk-screen “deck” and sold as a genuine product.
This kind of fake may not be able to detect the difference in the third-party functional test. The problem cannot be found until the fake product reaches the end customer and is officially launched. The loss at this point is not just a matter of payment for counterfeit products.
According to the announcement on the official website of the General Administration of Customs of China in early January 2021, on December 26, 2020, a Wuxi Electronic Technology Co., Ltd. declared to the Hong Kong-Zhuhai-Macao Bridge Customs affiliated to Gongbei Customs for the export of a batch of goods such as integrated circuits. When the on-site customs officers unpacked and inspected, they found that the batch of integrated circuits had the “ANALOG DEVICES” logo, a total of 17,500 pieces, and the value of the goods was 7,461,200 yuan. The owner could not provide a legal authorization certificate. (Related Reading)
It is reported that ANALOG DEVICES (Analog Semiconductor) is an American sensor manufacturer. After verification, this batch of goods is suspected of infringing the exclusive right to use the “ANALOG DEVICES” trademark registered with the General Administration of Customs.
According to industry insiders, the cost of MCU counterfeiting is relatively high, but under the soaring market, MCU also has the phenomenon of counterfeit chips.
21IC forum netizen imdx once posted at the end of 2020 that the “brand new and original” GD32F103C8T6 bought by a treasure, the pins look neat, the silk screen is also very clear, and the mark points are somewhat different from the previous ones. The actual test and debugging tool recognizes that it is indeed GD32F103C8T6, and it can also burn the program and run normally.
However, some chips (about 10%-40%) have low resistance to ground when the 3.3V power supply is powered on, resulting in a large standby current ranging from 10mA to 300mA. IMDX said that for a normal chip, before the program is flashed, the 3.3V input current is very small, lower than 2mA. Such a large current must be disassembled and polished. Looking at the UIDs of the chips, the UIDs of the same batch are very confusing. The UIDs of the chips from other suppliers are very similar behind the same batch.
It can be seen from the above “fake chip” cases that the current semiconductor industry fraud not only designs many types of semiconductors, but also covers a wider range of brands. There are both domestic semiconductor manufacturers and international semiconductor giants, both in the domestic market and overseas. market.
Now those who are engaged in electronics dare not use STM32 microcontroller, the price is really outrageous!
- How to produce fake chips?
There are hundreds of chips on a wafer. After the wafer is produced, it must be tested and marked with bad marks; the wafer that passes the test is cut and packaged. Chips that are marked as bad at the packaging stage are also discarded. Wafers that fail the test are recycled by the manufacturer who bought the bare chips, cut and bonded by themselves, but chips marked as bad are also discarded.
Usually the formal testing process is time-consuming and expensive, so some fabs will sell untested wafers to manufacturers that need bare chips, and the latter will test them themselves. However, the latter usually do not have good test equipment, and at the same time reduce test items to save money, so that some chips that could not pass in the semiconductor factory are used in the final product, resulting in unstable product quality.
Conscientious people took advantage of these loopholes and developed professional counterfeiting companies. It is undeniable that fake components have become a cancer of the supply chain.
In recent years, many contractors have stopped adding new suppliers once they have established a list of authorized suppliers. There is now a consensus among company purchasing departments that it does happen that production lines have to stop; however, when parts are unavailable from OEMs, OCMs and authorized dealers, purchasing personnel face few options. They can slow down or even stop production by not sourcing components, or buy from suppliers who have not been audited by their own organization or evaluated by any authorized third-party.
As a result, independent distributors, agents, and traders may supply them with components that are original, new, refurbished and used. The one-stop delivery of spot goods according to the BOM is called a distributor in the industry. It is common that they will represent several product lines themselves. For product lines that they do not have, they will buy/or transfer goods from other suppliers.
Almost all people in Huaqiangbei know that some people buy some electrical waste (commonly known as electronic waste) abroad for a long time, and then dismantle, sort, sort, refurbish, pack, and sell them in the electronic market after returning them.
- Various forms of counterfeiting
The primary counterfeiters are refurbished, with a place in Guangdong as a typical representative. It is to refurbish the old film (usually a disassembled film), and the pins can be turned to be the same as the new one if the pins are crooked.
A higher level of counterfeiting is polishing, making films with similar functions and sizes into more valuable films, and re-branding the logo, so commercial grades become industrial grades, industrial grades become military grades, military grades become 883 grades, and low speed becomes high speed. Low frequency to high frequency and so on.
Thanks to the price of small laser marking machines getting lower and lower, it is easy to use laser marking for refurbished ICs. Some traders will polish them themselves, and some will entrust professional polishing “counterfeiting lines”.
There is also a kind of counterfeiting that is at its peak. I personally suspect that a packaging factory is directly involved in it. This is not just as simple as polishing the logo, but it will directly turn dies of different sizes into another package.
The last kind of fraud, to the extreme, seems to be close to whitewashing. For example, sometimes when you go to Huaqiangbei to buy an MCU, the other party will ask you whether you want the original factory or the Taiwan version. There are two situations in the Taiwan version. One is a direct counterfeit product, and the other may be a Taiwanese version. It is produced, but it has also been tested and authorized by the original factory, but it may be a little worse in some indicators, so this kind of goods can not be regarded as fake.
Generally, the focus of system manufacturers’ incoming inspection is to check supply, labels, etc., and the ability to distinguish fake chips is really not enough. If you really want to measure the performance of the chip, you may need the original professional fixture.
So many people buy chips in Huaqiangbei
In addition, the material department and the R&D department are usually managed separately. Under normal circumstances, the sample engineer may find problems during the debugging process, but after the design is completed, it will not be tested again in the batch stage.
In addition, the level of counterfeiting is so high now that even the original engineer said that in many cases, it is impossible to distinguish the appearance by the naked eye. It came out weird, but to really determine whether it was a fake chip, you had to rely on advanced laboratory instruments.
- There are many kinds of fake chips
The chips we buy mainly include the following:
- Original original packaging
Products with original packaging.
If you order from the market, you still need to pay attention. Common problems include:
- Impersonation of domestic packaged goods: it is difficult to identify, only through comparison, there are still some differences in the outer box, label and packaging.
- Fake original packaging: Compare whether the label is different from the original label. The batch number on the label and the batch number on the chip should be the same.
The original packaging is very regular, and some will be wrapped in anti-static bags, but not all manufacturers’ products will have anti-static bags.
In the case of unopened antistatic packaging, the tube or tray inside should be clean after opening. If there are plastic foam or shock-proof plastic bags, these accessories from large foreign manufacturers are difficult to imitate in China, and the difference can be seen by comparison.
Take several films from a tube or plate and place them side by side. The content of the original product typing must be the same. The positions of typing, positioning holes and feet are relatively neat, and the content of the positioning holes is also the same. Of course, it is not excluded that some manufacturers do not have fixed positioning holes and typing positions, such as AVAGO.
The original packaging has been disassembled or there is no original packaging, but it is the original original product. Now many products in the electronic market are such original products. Belongs to bulk new goods.
Three, scattered new
According to the market situation, Sanxin can be divided into the following situations:
- The true meaning of scattered new
(1) The customer demand is lower than a whole package. Due to the price drive, the original whole package is disassembled, and a part of the number of chips is sold at a high price, while the remaining part of the film does not have the original package.
(2) For transportation reasons, the supplier disassembles the original packaged goods to facilitate transportation. Like the original goods from Hong Kong, they have to be shipped to Shenzhen and other places. In order to reduce customs duties, the original packaging has been dismantled, and multiple people have been brought into the customs.
(3) Old and new goods: Most of these goods are those that have been placed for a long time and have a bad appearance, which can only be used as loose new ones.
- The shoddy new sub-chips are the chips that have been eliminated from the IC assembly line due to internal quality problems and have not passed the test of the design manufacturer. Or chips that are also eliminated due to damage to the appearance of the chip due to improper packaging.
During the inspection process, because of the manual and computer inspection, the assembly line passes through the computer. Sometimes the film is not really a problem, but when it is just stuck, the staff would rather kill a thousand by mistake than let go of one. Bad films, so a lot of them are lost, then these become so-called loose new ones.
- Fake bulk new (ie refurbished goods) Many merchants in the electronics market often refer to refurbished goods as loose new goods.
Summary: There are various types of new bulk cargoes on the market. The first type of new bulk cargo (real new bulk cargo) can be assured in quality, while the second type of new bulk cargo (defective products) will be less likely to be scrapped in terms of rate and stability. Different from the original goods, these two types of products are very difficult to identify because they are both new. The third category of refurbished goods is even more harmful. It may be selling dog meat with the same appearance, but in fact, the functions are completely different. Therefore, it is best to avoid bulk new goods unless they are purchased on the basis of certain guarantees.
- One kind of refurbished goods in the true sense is the refurbishment of used goods. After the product is produced from the original factory, after use, there is a certain degree of wear and tear, and the performance is different from that when the original factory was just produced. After special processing, its appearance or performance is restored to close to the original factory just produced. status.
- The other is because the pins have not been oxidized for a long time or the pins are bumped, resulting in crooked feet, and the appearance of the film is repaired by re-adjusting the feet or plating the feet. Many years old and new bulk goods have actually undergone such processing, but the market is accustomed to defining this kind of goods as “bulk new”.
Summary: It is really a refurbishment of old films, and the quality is definitely better than the so-called loose new ones, even better than the quality of the original factory. Of course, there are also some one-off chips, such as one-time programming chips, with non-erasable programs, they can hardly be used again. The old bulk and new goods may have welding problems due to problems such as oxidation or crooked feet, resulting in problems with scrap rate and stability.
- How to identify genuine and fake chips
- See if there are any scratches on the surface of the chip
The surface of the polished chip will have fine lines and even the micro-marks of the previous printing, and some are coated with a thin layer of paint on the surface of the chip to cover it up, which looks a little shiny and has no plastic texture.
- Look at the print
The vast majority of chips are now laser marked or printed with a dedicated chip printer. The handwriting is clear, neither conspicuous nor blurred and difficult to erase. The refurbished chips have either the edge of the writing corroded by the cleaning agent and have a “jaggy” feeling, or the printing is blurred, different in shades, misplaced, easy to erase or too conspicuous.
In addition, the screen printing process has been eliminated by the current IC manufacturers, but many chip refurbishments still use the screen printing process due to cost reasons. This is also one of the basis for judgment. The words printed on the silk screen will be slightly higher than the surface of the chip, and you can feel the slight unevenness when you touch it with your hand. or a tingling feeling.
However, it should be noted that because the price of small laser marking machines has dropped significantly recently, more and more refurbished ICs are using laser marking, and some new chips will also use this method to change the wordmark or simply re-mark to “improve” the chip. This requires special attention, and it is difficult to distinguish the method, and it is necessary to practice “sharp eyes”.
The main method is to look at the overall coordination. The handwriting does not match the background and the newness of the pins. For example, if the wordmark is too new or too clear, there is a greater possibility of problems. However, many small factories, especially some small domestic IC companies. However, this method is very meaningful for judging the chips of mainstream manufacturers.
In addition, the phenomenon of using laser marking machines to modify chip marks has become more and more recently, especially in memory and some high-end chips. Once it is found that there are individual letters and stroke thickness in the position of laser printing, it can be identified as Remark. .
- Look at the pins
All tin-plated pins that are as bright as “new” must be refurbished. Most of the pins of genuine ICs should be so-called “silver powder pins”, which are dark in color but uniform in color, and there should be no oxidation marks or “flux” on the surface. “. In addition, the pins of DIP and other plug-ins should not have scratches. Even if there are scratches (only if they are packaged again), the scratches should be neat, in the same direction, and the exposed metal parts should be clean and free of oxidation.
- Look at the production date of the device and the label of the packaging factory
The label of the genuine product, including the label on the bottom of the chip, should be consistent and the production time should be consistent with the device, while the label of the unremarked refurbished chip is confusing and the production time is different. Although the label on the front of the Remark chip is the same, sometimes the value is unreasonable (such as what is marked with “auspicious number”) or the production date does not match the product of the device. If the label on the bottom of the device is confusing, it means that the device is Remark.
- Measure the thickness of the device and see the edge of the device
Many original laser-printed grinding and refurbished sheets (most of which are power devices) must be ground deeper to remove the original marks, so the overall thickness of the device will be significantly smaller than the normal size, but do not compare or measure with calipers, generally inexperienced people still It’s hard to tell, but a workaround is to look at the front edge of the device. Because the plastic-encapsulated device must be “released” after injection molding, the edge of the device is rounded (R angle), but the size is not large. It is easy to grind the rounded corner to a right angle during grinding, so the front edge of the device is right-angled once , can be judged as polished goods.
In addition, another method is to see whether the merchant has a large amount of original packaging, including cartons with consistent inside and outside labels, anti-static plastic bags, etc. In actual identification, multiple methods should be used, and if there is a problem, it can be determined quality of the device.