We know that the PCBA production process needs to go through several storage stages. It is often necessary to store for a certain period of time before the SMT chip processing is completed and the DIP plug-in processing is completed. After the PCBA board test is completed or the finished product is assembled, there is often a period of storage time, but different stages of storage The conditions and requirements are also different, the following Sanjing let everyone know:

(1) SMT is stored after processing. Under normal circumstances, after the SMT patch processing is completed, it will be placed in the DIP workshop for 1 to 3 days, sometimes even longer. For common types of boards, the temperature and humidity should be controlled between 22~30℃ and 30~60%RH, and the board can be placed on an anti-static rack. But for the PCB board of OSP process, the temperature and humidity requirements are relatively strict, and it needs to be stored in a constant temperature and humidity cabinet, and the soldering needs to be completed within 24 hours, otherwise the pads are very easy to oxidize.

(2) Store after PCBA test is completed. Generally, after the PCBA test is completed, the finished product will be assembled relatively quickly, so there is not much requirement for temperature and humidity control. But if it needs to be stored for a long time, it can be coated with three-proof paint and vacuum-packed. The ambient temperature is controlled at 22~28℃, and the humidity is controlled at 30~60%RH.

Generally speaking, the shelf life of PCBA processed products is 2~10 years, which is mainly affected by the following factors:

①Environment: A humid and dusty environment is not conducive to PCBA preservation, and will accelerate PCBA oxidation and dirt, thereby shortening the PCBA shelf life. Generally, it is recommended to store PCBA in a constant temperature of 25°C and dry and dust-free environment.

②Reliability of components: The reliability of components on different PCBAs also determines the shelf life of PCBA to a large extent. Components with high-quality materials and processes have the ability to withstand harsh environments. The wider the range of capabilities, the ability to resist oxidation. The stronger it is, it can provide a guarantee for the stability of PCBA to a certain extent.

③The material and surface treatment process of the circuit board. The material of the circuit board itself is not easily affected by the environment, but its surface treatment process is greatly affected by air oxidation. A good surface treatment process can extend the shelf life of PCBA.

④PCBA board operation load. PCBA operating load is the most important factor in its shelf life. The operation of high frequency and high load will cause continuous and high impact on circuit board circuits and components, and will be more susceptible to oxidation when heated, causing short circuits and short circuits during long-term operation. Open circuit phenomenon. Therefore, the operating parameters of the PCBA board should preferably be in the middle value range of the components and avoid near the peak value. This can effectively protect the PCBA and extend the shelf life.

In short, the shelf life of PCBA processed products is a comprehensive work, which needs to follow scientific design specifications, manufacturing process specifications, and operation specifications, so that the shelf life can be extended to the greatest extent.

The above is about the storage conditions and requirements of PCBA at different stages, I hope it can be helpful to everyone!