Waterproof structure of printed circuit board

An improved waterproof structure of a printed circuit board, including:

• an upper layer membrane and a lower layer membrane, wherein conducting lines for transmitting signals are printed on the upper and the lower layer membranes, and the conducting lines contains line channels and contact points;
• an insulation layer, wherein a plurality of go-through holes are provided thereon corresponding to the positions of the contact points of the conducting lines;
• besides, a plurality of ventilation holes located correspondingly to one another are provided on the upper layer membrane, the lower layer membrane, and the insulation layer respectively;
• and
• a waterproof unit, which is provided between the ventilation holes and the conducting lines;
• besides, a first channel and a second channel are provided on the upper layer membrane and the lower layer membrane respectively and correspondingly;
• also, the first openings and the second openings are provided on the two ends of the first channel and the second channel respectively;
• the first openings are connected to the line channels of the conducting lines, whereas the second openings are connected to the ventilation holes;
• besides, a pressure-adjusting hole, whose diameter is larger than that of the first channel and that of the second channel, is provided on the insulation layer corresponding to positions of the first channel and the second channel;
• the waterproof unit is formed by conjoining the first channel, the second channel, and the pressure-adjusting hole of the insulation layer so that the air generated by the contact points of the upper and the lower layer membranes due to receiving press-down force can be discharged to the outside, whereas the waterproof unit can block the external moisture from permeating into the conducting lines.