There are many and varied ic chips on the market, and it is sometimes difficult to see the difference between different materials without paying attention to the distinction. Now let’s look at some key points that distinguish original and new chips.
1. See if there are any polished marks on the surface of the chip
Every polished chip surface will have fine lines or even micro-marks printed previously, and some of them are covered with a thin coating on the chip surface, which looks a little shiny and has no plastic texture.
2. Look at printing
The vast majority of current chips are marked by laser or printed by special chip printing machines. The handwriting is clear, inconspicuous, indistinct and difficult to erase. The refurbished chip either has a “sawtooth” feeling due to the corrosion of the edge of the handwriting by the cleaning agent, or has blurred printing, different shades, incorrect position, easy erasure or too conspicuous.
Silk-screen printing technology has long been eliminated in large ic factories, but silk-screen printing technology is still used in many chip renovations due to cost reasons, which is also one of the judgment bases. The silk-screen printed words will be slightly higher than the chip surface, and slight unevenness or astringency can be felt by hand. However, the phenomenon of using laser marking machines to modify chip marks is increasing recently, especially in the memory and some high-end chips. Once individual letters and uneven strokes are found in the laser printing position, it can be considered as a renovation.
The main method is to look at the overall coordination. The handwriting is inconsistent with the background and the old and new level of the pins. For example, the handwriting is too new and too clear. However, many small factories, especially some small ic companies in China, have born this way chips. This has added a lot of trouble to the identification. However, it is still meaningful to judge the chips of mainstream large factories.
3.Check the pin
Tinned pins that are as bright as “new” must be refurbished. The majority of pins of positive ic should be so-called “silver powder pins”, with dark color but uniform color. There should be no oxidation marks or “flux” on the surface. In addition, pins of dip and other plug-ins should not have scratches. Even if there are (only if they are repackaged), the scratches should be neat, in the same direction, and the metal exposed areas should be bright and clean without oxidation.
4. look at the device production date and packaging factory label
The label of positive products includes the label of the bottom surface of the chip should be consistent and the production time should be consistent with the product of the device, while the label of remark is confused and the production time is different. Remark’s chip has the same label on the front, but sometimes the value is irrational (such as “lucky number”) or the date of manufacture is inconsistent with the product of the device. If the label on the bottom of the device is very confusing, it means that the device is remark.
5. Measure the thickness of the device and look at the edge of the device.
Many original laser-printed polishing and refurbishing plates (mostly power devices) must be polished deeper to remove the original marks, so the overall thickness of the devices will be significantly smaller than the normal size, but it is still difficult for the inexperienced people to distinguish without comparison or measurement with calipers, but there is an alternative method of detection, i.e. looking at the front edge of the devices.
Because plastic encapsulated devices must be “demoulded” after injection molding, the edge angle of the device is round (R angle), but the size is not large. It is easy to grind the rounded corner into a right angle during polishing. Therefore, once the front edge of the device is right angle, it can be judged as polished goods.
6. Look at the package
In addition, another method is to see if the merchant has a large number of original packaging materials, including cartons with consistent marks inside and outside, antistatic plastic bags, etc., which should be used together in actual identification. If there is a problem, the quality of the device can be determined.