Practice "Fire Eye" to distinguish between true and false IC

IC is the collective name for semiconductor device products. With the development of the IC industry, many industry players engaged in IC sales are trying their best to sell their IC products. However, most products in the current IC market are mixed and difficult to distinguish. In the following, Xiao Bian has summarized some “predecessors” methods for your reference.

Fake IC chip of the type <br> <br> first, disassemble the IC chip. This kind of IC chip is removed from the used circuit board. When you get your hand, it is obvious that there are traces of welding and the yellow area around the feet. If you have a large purchase volume, you must pay attention to the production lot number on the chip. It is certainly not uniform. This kind of chip is called disassemble IC chip.

Second, refurbish the re-typing chip. This type of IC chip has a beautiful appearance, each foot is also very beautiful, and the lot number is also uniform. For example, the most commonly used chips for multimedia speakers, some of these refurbished chips will have detailed models and batch numbers on the laser printing will sometimes include addresses, and the refurbished printing will be more vague, often only models and batch numbers.

The third kind, scattered new IC chips. One type of IC chip is not sold directly by the manufacturer QC. This kind of, and the original is no big difference, but the pass rate is relatively low, buy back, the current meeting, there are some, there are quality problems.

Buy chip to find agent

Generally, if the chip is purchased from the last 30 to 50 pieces, it is better to find the agent company or its distributor instead of going to the general “Taiwan” counter to get the goods. Generally, the spot on the counter (the so-called “Taiwan”) is basically Refurbished goods or old goods, and they look at people's quotes, experts or acquaintances, most of them dare not go too far, but ordinary people are still able to get into Mongolia, can deceive people and lie to them. This is indeed a relatively common phenomenon. Watch out. Even if you take goods at such a counter, you must make it clear that there are bad ones, and remember to "shop around." In addition, the transaction price should be much lower than the normal price, otherwise it is still looking for a formal agent. To know that a lot of processed old chips purchase price is only about 10% -20% of the market price of new films!

The main ways to distinguish between genuine and refurbished goods are:

1. See if the surface of the chip has been polished.

The polished surface of the chip will have fine lines or even micro marks previously printed on it. Some cover the surface of the chip with a thin layer of paint that looks a bit shiny and has no plastic texture.

2, see printing.

The vast majority of today's chips are laser-marked or printed on dedicated chip printers. They are clearly legible, unobtrusive, unambiguous, and difficult to erase. The refurbished chip either has a “sawtooth” etched by the cleaning agent on the edge of the writing, or has a blurred print, a different shade, a malposition, an easy erase or an overt eye. In addition, the screen printing process of the current IC manufacturers have long been eliminated, but many chip renewal because of cost reasons still use screen printing process, which is also one of the basis for judgment, silk screen printing words will be slightly higher than the chip surface, touch can feel the slightest uneven Or feel astringent. However, it should be noted that due to the recent sharp reduction in the price of small laser marking machines, more and more refurbished ICs adopt laser marking, and some new films will also use this method to change the word mark or simply replay to “enhance”. The grade of the chip, which requires special attention, and the method of differentiation is more difficult, need to train on the "eye of the eye." The main method is to look at the overall coordination, the handwriting and the background, the oldness of the pin is not the same as the possibility of new, too clear and problematic, but many small factories, especially domestic certain small IC companies The chip is born of this, which adds a lot of trouble for the identification, but the judgment of the mainstream manufacturers chip is still very meaningful. In addition, the use of laser marking machines to modify chip marks has become more and more frequent, especially in memory and some high-end chips. Once it is found that there are individual letters in the location of laser printing, and the thickness of strokes is uneven, it can be considered as Remark. of.

3, see the pin.

Where bright as the "new" tinned pins must be refurbished goods, most of the pins of the goods IC should be the so-called "silver powder feet", the color is dark but uniform color, the surface should not have oxidation marks or "flux In addition, the pins of DIP and Other plug-ins should not have any traces of scratches. Even if they are (re-packaging), the scratches should also be neat, in the same direction, and the metal exposed should be clean and free from oxidation.

4, see the device production date and packaging plant label.

The label of the genuine goods includes that the labels on the bottom surface of the chips should be consistent and the production time is consistent with the device's quality, while the labels of the refurbishment chips without Remark are confusing and the production time is not the same. Although Remark's chip has the same positive label, it may sometimes be numerically unreasonable (such as the "giry number") or the date of manufacture does not match the device's specifications. The label on the underside of the device is also confusing and indicates that the device is Remark.

5, measure the thickness of the device and see the edge of the device.

Many of the original laser-printed burnished fins (most power devices) must be polished deeper because the original mark must be removed, so that the overall thickness of the device will be significantly smaller than the normal size. However, people who are generally inexperienced are not compared or measured by calipers. It is difficult to distinguish, but there is a change in the general knowledge of the law, that is, to see the front edge of the device. Because the plastic sealing device must be "released" after injection molding, the edge angle of the device is rounded (R angle), but the size is not large. It is easy to grind this fillet to a right angle when grinding, so the front edge of the device is right angle once Can be judged as polished goods.

The above points of experience, I hope we all pay more attention to the reference comparison. Through careful observation, we can understand the truth of the IC chip.