What are the reasons for the damage of electronic chips? Method for measuring chip quality

Date：2022-03-02 17:18:00Views：2237

Chip is a way to miniaturize circuits in electronics, and is often manufactured on the surface of semiconductor wafers. In addition, chip has also been widely used in the fields of communication and network. So what is the general cause of chip damage?

(1) Supply voltage

You may laugh at this. The power supply of the chip on my system board is LDO output, which is very stable. How can I burn the chip. This is to start with two ways of chip burning program: On-board burning and seat burning.

For individual users or some specific industries, such as automotive electronics, most of them are used in board burning.

Another way is that factories use more for mass production, that is, block burning.

For many development boards or system boards designed by ourselves, the VCC of the debugging interface is generally pulled out directly from the chip power supply pin. If the power supply of the programmer is unstable, it is easy to cause overvoltage damage to the chip.

(2) Chip encryption

It is easy for ordinary developers to ignore this important function provided by the chip, but this function is particularly important when your product is going to sell. The encryption function can effectively prevent your product code from being copied.

(3) Programming high voltage

Some OTP (one-time programming) chips may need to program high voltage to write data. Although it is high voltage, in fact, many of them are about 6,7v, and even higher ones are tens of volts. This level of voltage is relatively safe for human body, but for many chips, it is already high voltage. Even some OTP chips that need this voltage to program cannot bear it for a long time, Therefore, some chips will specify the maximum time of high-voltage loading. Once this limit is exceeded, the OTP area may be permanently damaged.

In addition, there are many other factors that will damage your chip, such as whether the electrostatic protection can be done, whether the humidity and temperature of chip storage meet the requirements, and whether the temperature of chip welding is too high. In order to improve the yield of burning, we need to work from many aspects. However, the above details that are not easy to attract attention should not be ignored.

Method for measuring chip quality

The authenticity test is to test and identify whether the device is the device of the original semiconductor manufacturer by means of chemical corrosion and physical microscopic observation.

DC characteristic parameter test, through the special IC testing machine to measure and record the DC characteristic parameters of devices, and compare and analyze the performance parameters of devices, also known as static attitude test method.

Key function detection and verification: according to the description of the original device product or the application note or the application circuit of the end customer, evaluate and design the feasibility special test circuit, apply the corresponding effective excitation to the input pin pin through the peripheral circuit or port, and then use the general measuring instrument or indication form through the adjustment and control, signal amplification or conversion matching of the peripheral circuit, To test and verify whether the main functions of the device are normal.

Test all functions and characteristic parameters. According to the test vector provided by the original factory or the test vector written by your own simulation, use the IC test machine to test and verify the DC characteristic parameters of the device, all functions or working conditions of the device, but do not include the verification analysis of AC parameter characteristics. In other words, it completely covers the test items of level II and level III.

AC parameter test and analysis: after the successful completion of level V, and all test items meet the standards, the AC parameter test is carried out in order to further verify the characteristic parameters and edge characteristics of device signal transmission.

Measure the quality of the chip with a multimeter

If it is broken, the most common is breakdown damage. You can use a multimeter to measure the resistance or voltage of the power supply end of the chip to the ground. Generally, if it is within tens of ohms or the power supply voltage is lower than the normal value, most of it can be regarded as breakdown damage. You can disconnect the power supply end and measure whether the power supply is normal. If the measured resistance is large, it is likely that other ports are damaged. You can also measure other ports one by one. See if there is a port shorted to ground.

Special instruments for IC detection, but multimeter does not have this ability. Generally, the multimeter is used to detect the pin voltage when in use and make an approximate judgment, which is not reliable. And make judgment under the condition of being very familiar with this IC.