SMT SMD processing before the PCB must be baked? First of all, this issue can not be generalized, like the PCB board for the unpacking, and with desiccant and vacuum treatment, do not need. As the baking is for high-precision boards, or aircraft standards, military standards, must be baked, then refer to IPC standards!

       The primary intention of the PCB baking in the dehumidification moisture, remove PCB contained within or absorbed from the outside world of water, because some of the PCB itself is used in the material is simple to constitute a water molecule.

       In addition, PCB production out of a period of time will be absorbed into the environment of water, and water is the formation of PCB burst board (popcorn) or delamination (delamination) of one of the primary murderer.

       Because when the PCB is placed in a temperature of more than 100 ° C environment, such as back to the soldering furnace, wave soldering furnace, hot air flat or hand soldering and other processes, the water will become water vapor, and then rapid expansion, its volume is likely to expand the PCB, the circuit board between the layer and the layer of the conductive holes to pull off, and sometimes may be the formation of the PCB interlayer separation, the more serious and even the surface of the circuit board can be seen to be blistering, expanding the tortoise, Explode the board and other phenomena.

       Sometimes even if the PCB surface can not see the above phenomenon, but in fact, has been injured, followed by the passage of time and aging will form the function of electrical products is not stable, and ultimately the formation of product failure.