The Impact of Production Environment on the Reliability of Power Supply Products
In today’s society, AC/DC conversion and DC/DC conversion have gradually become a modular industry, and have gradually become an important part of various electronic equipment and automatic control equipment, and the quality and reliability of AC/DC power modules and DC/DC power modules also affect the reliability, failure rate and maintenance rate of the entire equipment to a large extent.
There are factors that affect the reliability of power supply products, such as design, process, management, testing and means, and incoming materials, which are the aspects that manufacturers of power modules pay attention to. In fact, the reliability of the power module should not only ensure the optimization of various performance indicators, but also ensure that the production environment of the power module is clean and orderly, with good electrostatic protection measures, appropriate temperature and humidity, and only under such conditions can the power module produced under such conditions be truly called a power supply product with high reliability.
With the continuous progress of society, electronic equipment plays an increasingly important role in industrial production, transportation, communications and other fields, the reliability of electronic equipment also determines the effective operation of various economic activities to a certain extent, and although the cost of power module in electronic equipment is very low, it can be called the “heart” of electronic equipment, and the failure of power module may directly lead to the paralysis of electronic equipment, resulting in irreparable losses.
- Electrostatic protection:
In the process of manufacturing, storage, transportation and assembly of components, due to the relative movement of instruments and equipment, materials and operators, electrostatic voltage may be generated due to friction, and when the device is in contact with these charged bodies, the charged bodies will be discharged through the device, causing the device to fail.
Most modern integrated circuits use MOS circuits, and most of the power modules also use MOS tubes and integrated circuit chips. In the production of power modules, if you do not pay attention to electrostatic protection, it often leads to a high component failure rate. Even if the product has passed the test, it may cause slight damage to the MOS tube and integrated circuit chip due to static electricity during the manufacturing process, which will affect the life and reliability of the power module. After the introduction of electrostatic protection system in the production environment (using human body anti-static grounding, floor anti-static grounding and anti-static grounding of operating devices and instruments, etc.), the damage caused to MOS tubes and integrated circuit chips can be effectively avoided. Anti-static damage of electronic components is a complex system engineering, which runs through the whole process of system or equipment development and production. From component procurement, packaging, transportation, inventory, installation, commissioning, testing to user use, the whole process, all-round, and all employees should follow a series of relevant measures to prevent static loss. Protection is a systematic project, which requires the investment of equipment, personnel, and effective management and system. It can be seen that the quality of an electrostatic protection system directly reflects the quality management level of an enterprise and is a demonstration of the strength of an enterprise.
- Humidity:
Moisture can penetrate into the porous material, causing a leakage path between the conductors, generating oxygen, and reducing the insulation resistance and isolation withstand voltage due to moisture absorption of parts. However, excessive drying can also make some materials brittle, rough surfaces, and even static electricity. Therefore, the production environment will also have a certain impact on the reliability of the power supply.
Most power modules are produced by soldering components onto small pieces of PCB (printed circuit boards) and then potting the small pieces of PCBs with resin into the housing. In the production process, if the humidity of the production environment is high, especially in the rainy season in the south, the moisture in the air will condense on the PCB board and components, even if the bubbles are removed by the vacuum defoaming process when the resin is potted, the moisture on the PCB board and components cannot be removed. When the power module works at a high ambient temperature, the moisture on the PCB board and components vaporizes and expands, causing cracks in the power module, pulling off the internal transformer wires, or introducing moisture from the outside world, corroding the components inside the power module or causing a short circuit in the circuit inside the module. For occasions with high isolation voltage requirements, moisture on the PCB board and components will also reduce the isolation ability of the power module, and even cause the breakdown between the initial stages, which will have serious consequences.
Too low humidity will also cause too much dust to float in the air, which will affect the quality of the power module. Too low humidity can also generate electrostatic charges due to the movement of personnel, and even if protected by electrostatic protection systems, it may cause electrostatic damage or soft breakdown of components, causing the same consequences as described above
The introduction of air conditioning system and dehumidification system in the production environment can keep the humidity of the production environment at an appropriate level and avoid adverse effects on the reliability of the power module due to water condensation or excessive drying of air.