Judge whether the IC is good or bad, and how to judge the quality of the IC

Visual Inspection: View.

The baiic body has no cracks, blackening, lack of mouth and other obvious appearance DAO dysfunction.

Touch check: The internal circuit board is normally energized and capacitive.

In addition, if you touch the temperature of the IC body with your hands, the internal short-circuit temperature of some bad ICs will exceed 100 degrees.

Voltage resistance measurement: Use a multimeter to measure whether the voltage of the IC power supply, clock, reset and other output pins is normal according to the circuit diagram, and measure whether there is any difference between the resistance value of each corresponding pin to the ground and the normal circuit board.

ABA Switching Verification: Replace the suspicious IC with a new IC, and if the fault can be solved, install the old IC back to the original circuit board to see if the fault is re-displayed, so as to verify the quality of the IC.

Simple, see if the foot is broken, whether there is a breakdown, the focus universal meter to measure the simple voltage, whether the current is normal. This is what can be done at home, and the rest of the parameters require equipment for the internal wafer.

You can test it with a multimeter.

If you want to know the quality of the device, what kind of test should you choose? Generally in the DAO

IC test sockets can be used to detect ICs

IC test socket (test socket) is a standard test equipment that tests the electrical properties and electrical connections of IC devices to check for manufacturing defects and defective components.

The IC test socket is used for testing after IC packaging, which mainly consists of an upper cover plate and a base that are matched with each other. The inner capacity of the upper cover plate is provided with through holes, and plurality of test probes are arranged near the aforementioned through holes to contact the IC, and the internal capacity of each test probe is provided with test springs. The inside of the base accommodates at least one support seat, corresponding to the through hole of the upper cover, to carry the IC to be tested.

At least one support spring is arranged between the bearing seat and the base, and the distance between the through hole and the support seat is less than the thickness after IC packaging, and the elastic coefficient of the supporting spring is greater than the sum of the elastic coefficients of the plural test springs.

Benefits of using IC test sockets:

1) It can avoid the pressure loss of the IC to be tested due to the size of the test device.

2) It can avoid test failure caused by poor contact between the test device and the IC to be tested.

3) To improve the test yield and reduce the manufacturing cost.

1.There is professional IC testing equipment, which is very expensive, and generally only professional testing institutions or IC manufacturers will buy this kind of equipment.

2.If you are the end user of IC (electronics factory), there is no need to buy such equipment, the quality of IC is determined by the source of goods (** business), find a regular brand, regular * * business and control your * * business, design and use reference IC datasheet is good.

3.In most cases, a transistor diagram is used to test the characteristic curve of each pin of the IC for failure analysis, and the quality of the IC is judged by the characteristic curve.

There are many types of ICs, and there are different detection methods. For digital ICs, there are usually two tests. The first is to test the ICs on the wafers one by one, at the factory where the wafers are made, and mark the ICs that fail the test, and do not package them after the wafers are cut.

The other is to test the packaged IC, usually in a dedicated workshop in the packaging factory. On a general-purpose test bench, a specially designed beta version is used to digitally test each IC, and the test program is usually jointly designed by the IC design company and the test company, and the test time of each IC is billed in seconds.

The ratio of the number of ICs that pass the two tests to the number of dies after cutting is called "yield". This is an important metric that affects the cost of ICs. The yield rate of well-designed IC products is usually above 95%.

A new IC product also needs to undergo some physical characteristics tests and limit tests. These tests are not carried out on the production line, usually commissioned by the IC design company to carry out by a professional testing agency, and then the test results are written in the manual for the reference of the whole machine user.

First, although the quality of ** is good, but the quantity is too small and generally unwilling to take care of you, unless there is a spot and you come to pick up, if you order**, it may not be able to reach the minimum order quantity, and the delivery time may be too long for you to accept, it is not easy to apply for samples, unless you apply for the brand **. Brand information can be found at Antling Technologies**. Or go directly to the store to buy goods, the goods in the market are mixed, you must learn to distinguish the authenticity of IC.

A old chip: The chip is removed from the circuit board and then classified and processed, the pins obviously have traces of soldering, the spacing of the pins is obviously different, the size of the printed text and pattern on the surface, the font, the depth is different, the production batch number is generally different, and the origin identification on the back is more miscellaneous (not processed): the refurbished chip is a kind.

Much like a brand new film, there is basically no obvious difference in the size of the printed text and pattern on the surface, the font, the depth, and the batch number is also the same, but if you look closely at the surface of the chip, you will find that there are many tiny parallel scratches, and the origin identification on the back is not the same. Generally speaking, the grinding piece is mainly a new piece that is too long, or the batch number is more miscellaneous, and it is printed into a unified and relatively new production batch number and new packaging for the convenience of customers.

b.Scattered new chips: the size of the printed text and pattern on the surface of the chip, the font, the depth is different, the production batch number is generally not the same, the origin identification on the back is more miscellaneous, but there are no traces of use of the pins, but there are traces of oxidation, (there are also batch numbers consistent, no original packaging.)

Now there are manufacturers in the market who have re-packaged, and it is difficult to identify them if they are not professionals) Generally speaking, this kind of chip is the first business to collect the unused chips collected from various ways and re-flow them to the market!

c.Original chip: the size of the printed text and pattern on the surface of the chip, the font, the depth, the production batch number, the origin identification on the back is very consistent, the pins are very neat, there will be a bright hatred in the middle of the matte surface*, the tube word with the chip is very new, very transparent, not yellow.

The packaging is more formal. The label on the package generally has the manufacturer's verification information or the merchant's order code in it. (Sometimes according to the barcode of these labels, go to the manufacturer ** to check the authenticity) to summarize the above three chips:

The quality and stability of A is the worst, the quality and stability of B are second, and the quality and stability of C are your best choice! If your quality is the first and the cost is the second, you can buy directly from the **merchant. If it is required, it is discontinued, and there are no original stocks on the market.

Then you can only choose second!

The key points of electronic components long-term identification of original and non-original.

Xichuanghui original IC self-operated to teach you to find non-original vulnerabilities, because fake can't be real, there will always be many loopholes.