Third party testing company specialized in failure analysis of electronic components

Date：2021-08-09 15:01:30 Views：2181

Electronic information technology is the core of today's new technological revolution, and electronic components are the basis for the development of electronic information technology. Understanding the factors causing component failure in order to improve reliability is a necessary guarantee for the application of electronic information technology. The main failure modes of electronic components include but are not limited to open circuit, short circuit, burning, explosion, electric leakage, function failure, electrical parameter drift, unstable failure, etc. In order to promote the further development of electronic information technology, it is necessary to improve the reliability of electronic components, so we must understand the failure mechanism, mode and analysis technology of electronic components.

1. Meaning of failure

Failure refers to the failure of electronic components. The important components of various electronic systems or electronic circuits are generally different types of components. When it needs more components, it indicates that the complexity of its equipment is higher; On the contrary, it is low. Generally, circuit failure is defined as the loss of specified functions of the circuit system.

2. Classification of failures

According to different standards, the classification of failure generally includes the following classification methods.

Taking the failure cause as the standard: it is mainly divided into essential failure, misuse failure, accidental failure, natural failure, etc.

Take the failure degree as the standard: it is mainly divided into partial failure and complete failure.

Take failure mode as the standard: mainly divided into no function, short circuit, open circuit, etc.

Based on the severity of failure consequences: it is mainly divided into mild failure, serious failure and fatal failure.

In addition to the above, there are a variety of classification standards, such as taking the failure occasion and external performance of failure as the standard.

3. Failure mechanism

The failure mechanisms of electronic components also have different classifications, usually based on their causes, which can be divided into the following failure mechanisms.

① Surface deterioration: sodium ions of components are polluted, resulting in leakage in the channel γ Radiation damage, surface creep or breakdown, etc; ② Deterioration caused by design problems: refers to the design problems in the circuit, layout and structure of single components; ③ Internal deterioration: refers to instantaneous power overload and structural performance degradation caused by CMOS locking effect, secondary breakdown, heavy metal contamination, neutron radiation damage and material problems; ④ Damage caused by improper use: refers to electrical surge damage, electrostatic damage, damage caused by excessive temperature, fault caused by interference signal, etc; ⑤ Deterioration of metallization system: refers to aluminum electromigration, aluminum corrosion, aluminum notch, etc. in electronic components; ⑥ Package deterioration: it refers to corrosion of pipe legs, air leakage or short circuit or electric leakage caused by foreign objects in the shell.

4. Common methods of failure analysis

There are many techniques for failure analysis of electronic components, but the commonly used ones are mainly as follows. The details are as follows.

(1) Pull out insertion method. Pull out and insert method refers to monitoring the process of pulling out and inserting the component board or plug-in board, and judging whether the connection interface pulled out and inserted is the place where the fault occurs. It should be noted that when the pull-out and insertion method is used for failure analysis, there will be special conditions in the process of pulling out and inserting the component board or plug-in board, that is, the place where the state changes is sometimes not only the connection interface, but also other parts. Therefore, when applying the pull-out insertion method, we should pay attention to observe each part and subtle changes in order to make a correct judgment.

(2) Sensory discrimination. The sensory discrimination method is to judge whether there is abnormality by observing the shape of parts, sensing the temperature and hardness of parts by hand touch, nose smell and smell, and ear hearing sound. Sensory discrimination method is simple and economical, but the content that can be distinguished will be restricted by sensory ability.

(3) Power pull bias method. The power supply pull bias method refers to pulling the normal power supply and voltage to make it in an abnormal state, and then exposing weak links or faults, which can reflect the components and components that are faulty or on the verge of failure. This method is generally used in the case of fault caused by long working time or preliminary judgment that the fault is caused by power grid fluctuation. It is worth reminding that the power pull bias method is destructive. Before using this method, you must check the insurance coefficient or other factors. Remember not to use it casually.

(4) Replace the spare parts method. By monitoring the removed suspicious components or parts, and then replacing the qualified spare parts, compare and analyze the fault phenomena. If the fault phenomenon disappears, finally determine whether the fault source point is in the removed parts. This method is the method of replacing the spare parts.

The above describes several methods with high application frequency for failure analysis of electronic components. In addition, there are static and dynamic measurement methods; Raise and lower temperature method; Knock and pinch positioning method, etc.

5. Ideas of failure analysis

In order to effectively analyze the failure of electronic components, a clear idea must be formed. Generally, the failure analysis of electronic components is mainly carried out step by step according to this idea: ① determine whether it is failure; ② Define the ultimate purpose of failure analysis; ③ Starting from the failure phenomenon, list all doubts about the failure position; ④ Draw up a plan to eliminate doubts; Analyze the failure position level by level; ⑤ Envisage and list all possible causes of failure parts; ⑥ Test assumptions with experiments; ⑦ Propose and review the failure prevention scheme; ⑧ Test the effectiveness of the failure prevention scheme with facts; ⑨ Truly implement the plan to prevent failure.

6. Principles of failure analysis

The failure analysis of electronic components should follow relevant principles. Some commonly used principles are as follows.

(1) The principle of first primary and then secondary. Generally, the primary and secondary are judged by the degree to which the fault affects the function. After defining the primary and secondary problems, first solve the primary problems and then solve the secondary problems.

(2) The principle of scheme before operation. When conducting failure analysis, analysts must calm down first, come up with solutions in their minds, and then operate. Do not operate blindly, and then cause the failure of other larger components.

(3) The principle of general before special. First check the positions where failures often occur, and then check the positions where failures rarely occur.

(4) The principle of weak current before strong current. Generally, when testing the performance or judging the fault position of the failed whole machine or failed samples, the input signal and power supply power should be from weak to strong according to the specific situation. It is worth reminding that in the whole change from weak to strong, we must closely observe and record abnormal phenomena. In addition, it is also necessary to prevent sudden startup and shutdown caused by over full power, resulting in power impact, and finally disturbing the failure state, and then increasing the difficulty of failure analysis [5].

In addition, there are the principles of simplicity before complexity, security before power on, macro before micro, peripherals before host, static before dynamic, power off before replacement, public before special, etc.

To sum up, through the relevant research on the failure analysis technology of electronic components, we can understand the failure causes, failure modes, failure mechanism and some common analysis methods of electronic components. Electronic components are the source of complete electronic products. In order for electronic equipment or electronic system to operate normally and reliably, it is necessary to ensure the reliability of electronic components. Therefore, it is very necessary to master the technology of failure analysis of electronic components.