The SynJet is a method of cooling semiconductor products. This synthetic jet moves air back and forth through an opening bordering a small cavity. To do this, an electromagnetic driver causes a diaphragm built into one of the cavity’s walls to oscillate at a certain rate, causing air to move into and out of the cavity. The rapid cycling of air into and out of the housing generates turbulent, pulsating air jets that can be directed to precise locations where cooling is needed. The turbulent airflow acts like a scrub brush as it rolls down the heated surface, extracting heat and moving it to the mean flow of the channel. The vortex action continues down the length of the surface or channel being cooled, pulling hot air and replacing it with cooler, ambient air.
Synthetic jets are “zero-mass-flux” in nature comprised entirely of ambient fluid. They produce a fluid flow with finite momentum that adds no mass to the system. Also, unlike conventional jets, they generate the airflow at the nozzle, so they do not need complex plumbing.
The Synjet requires less airflow to cool the heat load, which lowers the acoustics. Since it does not use bearings, brushes, or other frictional parts, it also eliminates acoustic problems. This makes it suitable in noise sensitive applications.
A diaphragm built into the cavity wall oscillates causing ambient air to periodically move in and out of the cavity. During the ejection phase (the first three frames left to right), a vortex and jet form and transfer downstream. Once the vortex flow has extended well downstream, the cavity draws in ambient air surrounding the opening.
Filed Under: Semiconductor, Electronics • electrical