We usually at the time of an electronic product development, will naturally use many types of electronic components, however, the market of electronic components are not the latest batch, have a plenty of within 3 years, have a plenty of within five years, have a plenty of within 10 years, and we put the components within is not the last 2 years, called inventories,  And these inventory materials are not all can not be used, which is closely related to the structure of the components themselves, preservation environment, temperature, humidity, sealing or not.  

These components that have been in stock for a long time are naturally cheaper than the latest batch of components. When we buy components, how can we judge, identify the batch of components and determine which years of components are suitable for our use?  I would like to consider it from the following aspects:  

1, according to the stability of the component itself, such as we use more led lights WS2812B this lamp, it is need to be very strict to save, we suggest is to use a whole plate of material, with the latest batch, but like some resistance capacitance itself is stable, we can extend the time of some batches, basic can be within 3 to 5 years,  We also need to do the first sample test.  

2. We can also determine the real batch of the components by checking the silk screen of the components and the label on the package  

3. The first sample test should be carried out for all the patch components, and 3-5 patches should be affixed first to check the functional stability of PCBA  

4. Select well-known or reliable component suppliers to ensure the authenticity and reliability of the batch of components  

5. Carefully study the specification of the components, such as whether the temperature curve of reflow welding is consistent with the requirements of the components, so as to ensure that the components will not be damaged due to high reflow temperature  

Through the above inspection and process grasp, we can better ensure the stability of our PCBA products