How to identify the authenticity and authenticity of the chip? New authentic identification method

Date：2022-03-08 14:42:30Views：1903

With the advent of the electronic information age, there are a wide range of electronic products on the market, as well as various electronic components such as IC chips and diodes, which are difficult to distinguish between true and false. We not only need to buy genuine products, but also need to buy chips with matching models, so that we can use such chips normally and purchase quality guaranteed chips through formal channels. However, there are many products in the market. As a purchaser, how to identify the authenticity and authenticity of the chip? Share new authentic identification methods for reference only.

The main methods to distinguish the original goods from the new ones are as follows:

1. Check whether there are any polished marks on the chip surface

The polished chip surface will have fine lines or even micro marks of previous printing. Some are also coated with a thin layer of paint on the chip surface to cover up, which looks a little shiny and has no plastic texture.

2. Look at the printing

Now the vast majority of chips are printed by small character inkjet printer. The handwriting is clear, inconspicuous, fuzzy and difficult to erase. The refurbished chip either has a "sawtooth" feeling due to the corrosion of the writing edge by the cleaning agent, or the printing is fuzzy, different in depth, incorrect in position, easy to erase or too conspicuous. The silk screen printing process has long been eliminated by the current IC manufacturers, but many chip renovations still use the silk screen printing process due to cost reasons, which is also one of the judgment basis. The words printed on the silk screen will be slightly higher than the chip surface, and you can feel slight unevenness or astringency by touching with your hand.

3. Look at the pins

All tinned pins that are as bright as "new" must be refurbished goods. The vast majority of the pins of genuine IC should be so-called "silver powder feet", with dark color but uniform color, and there should be no oxidation trace or "flux" on the surface. In addition, the pins of dip and other plug-ins should not be scratched. Even if there is (only after re packaging), the scratches should be neat and in the same direction, and the metal exposure should be bright and clean without oxidation.

4. Look at the device production date and packaging factory label

The label of genuine goods, including the label on the bottom of the chip, shall be consistent, and the production time shall be consistent with the device products. The characters sprayed by the inkjet printer shall be clear and unified, while the label of the updated film of remark is chaotic, and the production time is different. Although the front label of the remark chip is consistent, sometimes the value is unreasonable (such as "lucky number") or the production date is inconsistent with the device product. If the code spraying characters on the bottom of the device are very chaotic, it also indicates that the device is remark.

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

Many of the original laser printing polished and renovated pieces (mostly power devices) must be polished deeply to remove the original mark. In this way, the overall thickness of the device will be significantly less than the normal size, but it is difficult for people with insufficient experience to distinguish without comparison or caliper measurement. However, there is an alternative way to see through, that is, to look at the front edge of the device. Because the plastic encapsulated device must be "demoulded" after injection molding, the edge angle of the device is round (R angle), but the size is small. It is easy to grind this fillet into a right angle during grinding. Therefore, once the front edge of the device is at a right angle, it can be judged as polished goods. In addition, another method is to see whether the merchant has a large number of original outer packaging materials, including cartons with consistent internal and external marks, anti-static plastic bags, etc. in the actual identification, multiple methods should be used together. If there is a problem, the quality of the device can be determined.

The best way to avoid the risk of counterfeit goods inflow is to try to buy components from authorized formal channels and take photos of each batch of purchased products for retention. The identification methods of brand-new genuine products are as follows:

(1) Appearance inspection: optical microscope is usually used for appearance inspection to check whether the coplanarity of the chip, the printing on the surface, the device body and pins meet the specific requirements.

(2) X-ray inspection: X-ray fluoroscopy is a nondestructive inspection method, which can observe the internal structure of the object from multiple angles. Through X-ray perspective, check whether there are physical defects in the grain, lead frame and gold wire inside the enclosure of the tested device.

(3) Acetone wipe test: acetone wipe is to regularly wipe the silk screen on the front surface of the chip with a certain concentration of acetone. The result is used to judge whether the chip surface is reprinted.

(4) Unsealing and capping test: unsealing and capping is a physical-chemical test, which dissolves the epoxy resin colloid on the outer surface of the chip and retains the complete grain or gold wire, so as to check the important marks, layout, process defects, etc. on the grain surface.

(5) Lead free detection: use SEM / EDS to detect the pins or terminals of parts to confirm whether they contain lead. Test data and reports can be provided.

(6) Electrical test / function test: use IV curve tracker and probe table to test the curve of IC pins and gold wires after unsealing, including mass production test, open and short circuit test and leakage current test.

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