How to distinguish true and false chips

There are all kinds of chips on the market now, so do you know how to identify fake chips? The focus of this article is still on the identification of original goods and new loose goods; but the other situation is more serious, that is, many low-end brand counterfeit products , directly printed with the logo of the high-end brand, and sold as original goods.

When it comes to the authenticity of components, it is nothing more than the need to identify whether the components are original or new. The loose new goods mentioned here are refurbished parts or dismantled parts. They are components that have been processed and reprocessed, so people in the industry generally call them loose new goods. At the same price, everyone wants to buy new devices with brand-new functions, so this requires some common sense to distinguish which ones are original new products and which ones are what we call new parts.

1. Check whether there are any traces of polishing on the surface of the integrated circuit chip. There will be fine lines and even traces of previous printing on the surface of polished chips. In some cases, a thin layer of paint is applied to the surface of the chip to cover it up. It looks a bit shiny and has no plastic texture.

2Look at the printing. Most of today's chips are marked with lasers or printed with special chip printers. The writing is clear, not conspicuous, not blurry, and difficult to erase. The refurbished chips either have edges that are corroded by cleaning agents and have a "jagged" feel, or the printing is blurry, different shades, incorrectly positioned, easy to erase, or too conspicuous. In addition, the screen printing process has long been eliminated by major IC manufacturers, but many chip refurbishments still use the silk screen process due to cost reasons. This is also one of the basis for judgment. The silk screen characters will be slightly higher than the surface of the chip, and you can feel the slight unevenness by touching it with your hands. Or feel astringent.

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. Some new ICs will also use this method to change the word mark or simply re-mark to improve the quality of the chip. Grade, this requires special attention, and the method of distinguishing is more difficult, so you need to develop a "fierce eye". The main method is to look at the overall coordination. If the handwriting does not match the background or the pins, if the word mark is too new or too clear, there is a greater possibility of problems. However, many small factories, especially some small domestic IC companies, The chips are born like this, which adds a lot of trouble to the identification, but this method is still very meaningful for judging chips from mainstream manufacturers. In addition, recently, there are more and more cases where laser marking machines are used to modify chip marks, especially in memory and some high-end chips. Once it is found that individual letters are uneven in the laser printing position and the thickness of the pen is uneven, it can be determined that It's Remark's.

3Look at the pins. All tin-plated pins that are as bright as "new" must be refurbished products. Most of the pins of genuine ICs should be so-called silver-pink pins, which are darker in color but uniform in color, and there should be no traces of oxidation on the surface. In addition, the pins of DIP and other plug-ins should not have scratches. Even if there are scratches (which will only occur after repackaging), they should be neat and in the same direction, and the exposed metal parts should be smooth and non-oxidized.

4. Look at the device production date and packaging factory number. The markings of genuine products, including the markings on the bottom of the chip, should be consistent and the production time should be consistent with the device. However, the markings of unremarked refurbished pieces are confusing and the production time is different. Although Remark's chips have the same markings on the front, sometimes the values ​​are unreasonable (such as what "auspicious number" is marked) or the production date does not match the device. If the markings on the bottom of the device are confusing, it also means that the device is Remark.

5. Measure the thickness of the device and look at the edge of the device. Many polished and refurbished pieces of original laser printing (mostly power devices) must be polished deeply to remove the original marks. In this way, the overall thickness of the device will be significantly smaller than the normal size. However, without comparison or measurement with calipers, generally inexperienced people still can. It's difficult to tell, but there is a way to see through it, which is to look at the front edge of the device. Because the plastic package device must be "demoulded" after injection molding, the edge corner of the device is rounded (R-angle), but the size is not large. It is easy to grind the rounded corner into a right angle during grinding, so the front edge of the device is once right-angled. , can be judged as polished goods. In addition, another method is to check whether the merchant has a large number of original outer packaging, including cartons with consistent internal and external markings, anti-static plastic bags, etc. In actual identification, multiple methods should be used. If there is a problem in one place, it can be identified The quality of the device. If there is a chip that we cannot judge with the naked eye and experience, we can use a writing tool, such as a magnifying glass and a digital magnifying glass to polish the refurbished chip table. If there are tiny holes that are difficult to see with the naked eye, we must use Equipment to observe! There are several key points:

1). Look at the typing. Generally, refurbished and re-typed (white characters) can be erased with chemical thinner. The original ones cannot be erased.

2) Look at the lead angles. The original leads are very neat and straight like a straight line, while the refurbished ones have uneven leads and are a little crooked.

3) Look at the positioning holes. Observe that the positioning holes of the original products are relatively consistent. Some of the refurbished ones have different shades or are completely polished. In some cases, if you look carefully, you can see traces of the original positioning holes. In actual work, you must carefully observe and observe. Some counterfeiting techniques are quite high, so you must be particularly cautious when purchasing! The above is the method for distinguishing true and false chips. I hope it will be helpful to everyone when purchasing.