[carteman]

The plastic sealing and packing is becoming a standard way when the electronics component develops toward the direction of smaller and cheaper. But the damp air would seal into the inner part of the component and it causes that the internal electric circuit is oxidized and decayed, on the other hand, the high temperature in the process of welding would make the damp air inside the IC inflate and produce enough pressure when the absorbing humidity rate of the SMD is to 0.1wt% per hour so as to make the plastic take off from the chip, the connection between the lines is damaged, the chip to hurt, etc. The more important is that those unseen and latent blemishes would dissolve into the products.
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