The development of automotive technology makes more and more ECUs are applied (such as engine ECU, ABS ECU, ESP ECU, fan cooling module). Therefore, the normal operation of the ECU is more and more related to the performance of the entire system. The function of the engine ECU is to receive signals from various sensors, complete the processing of this information, and issue corresponding instructions to each actuator, so that the engine performance, fuel consumption and exhaust emissions are in an optimal state. For ECUs, the increasing speed of their microprocessors is a contradiction between sensitivity and narrow housing. The improvement of the performance of the microprocessor generally brings the increase of temperature and pressure, which requires more and more space to release heat and reduce pressure. The excellent breathability of protective products solves this problem very well. It guarantees the sealing of the casing while maintaining the air circulation inside and outside the casing. Thus, the microprocessor in the housing is prevented from being polluted by water, oil, moisture and solid pollutants, thereby improving the reliability of the ECU and extending the life of the ECU. At the same time, it reduces the requirements for seals and shortens the design and assembly time, thereby saving the overall cost of the ECU.