Micro Cooling Fan must be installed securely in order to reduce noise

Imagine if the "Micro Cooling Fan" not very firmly fixed on the heat sink, but a very loose, so a fan in high-speed rotation process will produce what kind of phenomenon? Many people will certainly blurted, fans will certainly have a very strong noise, in fact, this was a very one-sided. Although the market many "Micro Cooling Fan" is the cooling fan is firmly fixed on the heat sink, but also a fan and did not secure the fan directly to the heat sink, but fixed in a plastic frame. We all know that one source of the noise of the fan is caused by resonance, in order to reduce the noise caused by such reasons, many "Micro Cooling Fan" by an elastic plastic frame has fixed so that it can play to prevent resonance effect.