Automotive Design Robert
Chamberlain looks at how to ensure the long-term functionality of electronic parts in vehicles.
Venting protects electronics against environmental impacts
I
n vehicles, mechanical parts are increasingly replaced by electronic components. Driver assistance systems such as adaptive cruise control or lane-assist become more and more common, and the number of electronic components built into vehicles is constantly rising.
That is why today, more than ever, car manufacturers and their suppliers have to look for effective ways to protect in-vehicle electronics against environmental impacts and failures.
All electronic components – whether part of compressors, pumps, motors, control units or sensors for increasingly popular active security systems – are subjected to huge temperature fluctuations throughout their service life. These can arise when the component’s housing heats up in operation and then comes
into contact with cold spray from the road or at the carwash. These fluctuations in temperature can cause a significant vacuum to develop inside the electronics housing. The resulting pressure differential can be so strong that the seals and sealing components protecting the sensitive electronics can be seriously compromised, letting in dirt particles and liquids that can corrode the component and shorten service life.
One major challenge facing the automotive industry is the thermal management of high-performance electronics and batteries in electric vehicles, since these components need to operate in a certain temperature range in order to achieve optimum performance. They get very hot when running and need to be cooled using fluids. This can cause such huge temperature differentials within the electronic unit itself
Fig. 1. The graph shows the continuous buildup of negative pressure within a hermetically sealed housing.
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Fig. 2. Venting components requires greater airflow per membrane surface area, resulting in a lower water entry pressure.
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