Creative core testing teaches you how to test IC chips

Date：2021-10-20 15:22:19Views：1287

Chip is the core of intelligent equipment. Just like the engine of automobile, it plays a key role in the whole product. Therefore, the quality of IC chip plays a very important role in the whole electronic products, and it affects the quality problems of the whole products after they go on the market. For more precise electronic components, the required electronic components (transistors, diodes, resistors, capacitors, inductors and other components) are encapsulated in a tube shell to become the functional micro structure required by the circuit. The more precise the structure is, the more difficult the detection is. In order to ensure whether there are quality problems in IC chips, general enterprises usually detect IC chips. Creative core testing teaches you how to test IC chips.

1. Off road detection

This method is carried out when the IC is not welded into the circuit. Generally, the forward and reverse resistance values between each pin corresponding to the grounding pin can be measured with a multimeter, and compared with a intact IC.

2. On road detection

This is a method to detect the DC resistance of IC pins in the circuit (IC in the circuit), AC / DC voltage to ground and total working current through a multimeter. This method overcomes the limitation of substituting IC and the trouble of disassembling IC. It is the most common and practical method to detect IC.

3. DC working voltage measurement

This is a method to measure the DC power supply voltage and the working voltage of peripheral components with the DC voltage gear of multimeter when powered on; Detect the DC voltage value of each IC pin to the ground and compare it with the normal value, so as to compress the fault range and find out the damaged components. Pay attention to the following eight points during measurement:

(1) The multimeter should have enough internal resistance, which should be at least 10 times greater than the resistance of the measured circuit, so as not to cause large measurement error.

(2) Usually turn each potentiometer to the middle position. If it is a TV, the signal source should adopt a standard color bar signal generator.

(3) Anti skid measures shall be taken for the probe or probe. IC is easily damaged due to any instantaneous short circuit. The following methods can be adopted to prevent the probe from sliding: take a section of bicycle valve core and cover it on the probe tip, and grow the probe tip by about 0.5mm, which can not only make the probe tip in good contact with the tested point, but also effectively prevent slipping, and there will be no short circuit even if it touches the adjacent point.

(4) When the measured voltage of a pin is inconsistent with the normal value, it shall be analyzed according to whether the pin voltage has an important impact on the normal operation of the IC and the corresponding changes of other pin voltages, so as to judge the quality of the IC.

(5) IC pin voltage will be affected by peripheral components. In case of leakage, short circuit, open circuit or variable value of peripheral components, or a potentiometer with variable resistance is connected to the peripheral circuit, the pin voltage will change due to the different position of the sliding arm of the potentiometer.

(6) If the voltage of each IC pin is normal, the IC is generally considered normal; If the pin voltage of IC part is abnormal, start from the maximum deviation from the normal value to check whether the peripheral components are faulty. If there is no fault, the IC is likely to be damaged.

(7) For dynamic receiving devices, such as TV sets, the voltage of each pin of IC is different when there is no signal. If it is found that the pin voltage should not change, but does not change with the signal size and different positions of adjustable components, it can be determined that the IC is damaged.

(8) For devices with multiple working modes, such as video recorders, the voltage of each IC pin is also different under different working modes.

The above is the related content of "IC chip detection" brought by the core creation test. I hope it can be helpful to you. We will bring more wonderful content in the later stage. The company's testing services cover: electronic component testing and verification, IC authenticity identification, product design and material selection, failure analysis, function testing, factory incoming material inspection, tape braiding and other testing items. Welcome to call Chuangxin testing, we will serve you wholeheartedly.