What is a power module?
The power module is called the energy supply station in the circuit. It converts the required current into the direct current or alternating current required by the user through voltage conversion.
The power module can provide stable AC and DC power output for instruments or control devices in related systems. And stable current can bring isolation, protection, voltage conversion, voltage stabilization, noise reduction and other functions to the circuit.
The main components of the power module include electrolytic capacitors, optocouplers, printed circuit boards, semiconductor devices, switch transformers, potentiometers, fuses, etc. The modular structure brings the advantages of high adaptability, high reliability, high power, easy maintenance, and wide application.
Due to the many advantages of modular structures, modular power supplies are widely used in communication, automotive electronics, aerospace, and other fields.
Failure of power module
The failure of a power module is usually caused by internal and external factors that result in the degradation of its internal components.
Internal factors are mainly caused by non compliant design or application of production materials, board design, assembly, and packaging.
External factors mainly include electrical stress, electrostatic discharge, and overload. The most common external factor is that when the temperature is high, the power module is prone to aging and degradation, which can lead to failure and serious consequences.
The common failure modes of power modules are as follows:
|
Failure Mode |
Reason |
|
open circuit |
There are different reasons for power module products at different stages: one of the common causes of open circuit failure in new power modules is defects in the solder joints during the manufacturing process, resulting in loose connections; The common causes of open circuit failure during use are vibration leading to electrical connection failure, or degradation of internal components. |
|
short circuit |
When a short circuit fault occurs in the power module, it can cause damage to the internal components, thereby damaging the power module. Instantaneous high voltage, aging of components, and loss of insulation medium can all lead to short circuits in power modules. |
|
Unstable output value |
The unstable output value to some extent implies that some components inside the power module have aged, degraded or damaged, such as capacitors, transistors, etc., or that the voltage regulator is damaged. |
|
Output is too high |
The reasons for the high output of the power module include internal capacitors, aging and degradation of diodes, open circuit of one or more rectifier diodes, and inter turn short circuit of the primary coil of the transformer. |
|
Low output |
When the load carried by the power supply exceeds its own capacity, there will be a phenomenon of low power output. |
|
Ripple too high |
When the output of the power module exceeds the tolerance and is accompanied by high amplitude power frequency or harmonic ripple, it indicates that the main filtering capacitor has aged and failed. |
Any of the above reasons may lead to the overall failure of the power module, resulting in instability or failure of the entire circuit, causing significant losses in daily life or production.
Screening power modules can eliminate power modules that have aged and failed in the early stages. Therefore, it is extremely important to screen qualified power module products before delivery for use.
The service capability of GRGTEST
A qualified power module must have input and output electrical parameters within the qualified range, so electrical parameter testing of the power module is an important part of power module screening.
To this end, GRGTEST has introduced the CHEMA 8000 power module testing system, which quickly, accurately, and comprehensively tests the electrical parameters of various models and specifications of power modules.
GRGTEST usually conducts the following routine electrical parameter tests on power modules to evaluate their performance:
- Output accuracy test
- Ripple test
- Efficiency testing
- Dynamic response testing
- Overcurrent protection test (short circuit protection)
Chroma 8000 Power Module Testing System
Test interface