Chip buyers must see! 9 ways to distinguish the authenticity of the chip

1. Check the outer box, labels, and packaging.

Authentic packaging is usually neat and orderly, with proper labels that are traceable.

Some may come wrapped in anti-static bags, but not all manufacturers provide this. If the anti-static packaging is unopened, the tubes or discs inside should be clean. If there are plastic foam or shockproof plastic bags, it's difficult for domestic manufacturers to imitate these accessories from foreign major factories, and differences can be observed through comparison.

1. Check the reel and film.

The original packaging reels are usually very neat and flawless, while loose ones may have defects. Careful observation may reveal that the reels and films are not very tidy.

1. Look for signs of polishing on the surface of the chip.

Any chip that has been polished will have fine lines or even faint traces of previous printing. Some chips may also have a thin layer of coating on the surface to cover it up, giving it a slightly glossy appearance without the plastic texture.

1. Examine the printing.

Most chips nowadays are either laser-marked or printed using specialized chip printers, resulting in clear and durable markings. Refurbished chips may have markings that are either corroded along the edges due to cleaning agents or blurry, inconsistent in depth, position, or easily erasable, or overly conspicuous. Additionally, while silk-screen printing technology has been phased out by major IC manufacturers, many refurbished chips still use it due to cost reasons. This is also one of the criteria for judgment, as the printed characters will be slightly higher than the chip surface and can be felt to be uneven or slightly rough when touched.

However, it is worth noting that due to the recent significant decrease in the price of small laser marking machines, more and more refurbished ICs are using laser marking. Some refurbished chips may also use this method to change or re-mark the characters to improve the chip's grade. This requires extra attention, and the differentiation method is relatively difficult, requiring the development of a discerning eye.

The main method is to observe the overall coordination, such as whether the characters match the background, whether the new and old levels of the pins match. If the characters are too new or too clear, there may be a problem, but many small factories, especially some small IC companies in China, produce chips like this naturally, which adds a lot of trouble to identification. However, this method is still meaningful for judging mainstream chips from major manufacturers.

1. Check the pins.

Brightly tinned pins like "new" are usually refurbished, while genuine IC pins should mostly have a so-called "silver powder foot", with a darker but even color, and the surface should not have oxidation traces or "solder flux". In addition, the pins of DIP and other plugins should not have scratched traces. Even if there are scratches (only after repackaging), they should be neat, in the same direction, and the exposed metal should be clean and without oxidation. Also, the pins of original products are very neat and straight, while those that have been refurbished may have uneven pins and some may be crooked.

1. Look at the production date and packaging factory code of the device.

The markings of genuine products, including the markings on the bottom of the chip, should be consistent, and the production time should match the device grade. The markings of unre-marked refurbished chips are chaotic, with inconsistent production times. Although the markings on the front of re-marked chips are consistent, sometimes the values are unreasonable (such as marking "lucky numbers") or the production date does not match the device grade. Chaotic markings on the bottom of the device also indicate that the device is re-marked.

1. Measure the thickness of the device and look at the edge of the device.

Many refurbished chips with original laser-marked printing (mostly power devices) need to be polished deeply to remove the original markings. As a result, the overall thickness of the device will be significantly smaller than the normal size. However, without comparison or measurement with a caliper, it is still difficult for people with limited experience to distinguish. However, there is a trick to identify them: look at the edge of the device.

Since plastic-packaged devices need to be "demolded" after injection molding, the edges of the devices are rounded (with a radius). However, the size is not large, and it is easy to grind this rounded edge into a right angle during polishing. Therefore, once the edge of the device is a right angle, it can be judged as polished goods.

1. Look at the positioning holes.

Observing the positioning holes of original products is relatively consistent, while refurbished products may have varying depths or may have been completely polished. Some of them, if carefully observed, may show traces of the original positioning holes. In actual work, careful observation is required, as some counterfeit processes are quite sophisticated, and extra caution is required in procurement!

1. Evaluate the chip through technical personnel and professional testing equipment.

If there are some chips that cannot be judged by naked eyes and experience, we can use some tools, such as magnifying glasses and digital magnifiers. It is difficult for us to see the slight pores on the polished and refurbished chip surface with naked eyes, so we must use equipment for observation. The main testing methods are as follows:

(1) Visual inspection: Visual inspection usually uses an optical microscope to check the coplanarity of the chip, the printing on the surface, the main body of the device, and the pins to see if they meet specific requirements.

(2) X-ray inspection: X-Ray penetration inspection is a non-destructive inspection method that can observe the internal structure of objects from multiple angles. Through X-Ray penetration and inspection, the physical defects of grains, lead frames, and wires inside the sealed body of the tested device can be checked.

(3) Acetone wiping test: Acetone wiping is to wipe the regular printing on the surface of the chip with a certain concentration of acetone regularly, and the result is used to determine whether the surface of the chip is reprinted.

(4) Decapsulation test: Decapsulation is a physical and chemical combined test, which dissolves the epoxy resin gel on the outer surface of the chip, retains intact grains or gold wires, and facilitates the inspection of important marks on the surface of the grains, layout of maps, process defects, etc.

(5) Solderability test: It is used to judge whether the component can be normally mounted and whether the solderability of the component pins or solder joints meets the specified requirements, and to judge whether the ability to solder to the board is stable and reliable.

(6) Electrical test/functional test: Use an IV curve tracer and a probe station to perform curve tests on various pins of the IC and various gold wires after decapsulation, including mass production tests, open/short circuit tests, and leakage current tests.

In summary, the best way to avoid the risk of counterfeit components entering the market is to purchase components through as formal channels as possible and take photos of each batch of purchased products for retention.