Why pre-bake PCBA before processing?

 PCB board and electronic components need to be baked before PCBA processing, among which, the board baking temperature is relatively fixed, generally at 120 ° C ±5 ° C, and the baking time is determined according to the board or electronic components stored time, the longer the storage time of the board, the longer the baking time is required. So why bake the board before PCBA processing?


The main purpose of pre-baking before PCBA processing is to remove the excess water in the PCB board, we all know that the PCB substrate is mainly based on glass fiber board, paper substrate and metal plate, and like glass fiber board and paper substrate board quality not only does not moisture-proof, but also absorbs moisture in the air if it is exposed to the air for a long time. If the PCB board is not pre-baked before processing, then the water vapor inside the PCB board will be quickly converted to water vapor at high temperature during processing, and the corresponding volume will also expand rapidly, resulting in the phenomenon of PCB bursting or bubbles. It is necessary to pre-bake the board before PCBA processing to remove excess moisture inside the board;

As for the baking time of PCB, it is determined according to the storage time of the board, in general, the storage time is less than a week of PCB only need to bake for 1 hour, the storage time is within 1 month to 6 months of PCB needs to bake for about 2 hours, and the storage time in half a year to a year of PCB needs to bake for at least 4 hours. As for the storage time of more than one year PCB board is generally not recommended to use and do scrap treatment; If you have to use it, you need to bake it for at least 6 hours.

And usually we can extend the storage time of PCB by the following points, one is the surface treatment of the board when the board is made, the second is the vacuum sealed packaging when the board is stored, and finally, it is necessary to ensure that the temperature and humidity of the PCB storage space are at a normal level, through these methods can effectively extend the storage time of PCB.

If you’re interested in PCB&PCBA products, pls kindly email to Sandy: sales9@hitechpcb.com


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