A heat sink is an electronic gadget or a component of an electric circuit which disperses heat from other components like power transistors into the surrounding medium. Fundamentally, it’s responsible for cooling them down by improving the performance and reliability and alongside, avoids the premature failure of the components. For cooling purposes, either it has a fan or cooling device.
Heat sink principle:
The law of Fourier’s regarding heat conduction claims that if there is an availability of temperature gradient inside the body then the transfer of heat occurs from high-temperature region to low-temperature region and this can only be accomplished in three ways including convention, radiation, and convection.
If different objects collide with different temperatures, conduction occurs, which causes the fast-moving molecules of high-heat object contact with the slow-moving molecules of the cooler objects, and hence thermal energy is transferred to the cooler object. Similarly, heat sink transfers heat energy from the high-temperature components to a low-temperature medium like oil, water, air, etc.
The heat sinks are classified into several categories based on different criteria.
Some of them include
Active heat sinks: Typically, they have a fan type structure and utilize power for cooling purposes. The fans are further classified in ball bearing type and sleeve bearing type. The ball bearing fan has a longer working span and also it’s cost-effective.
Passive heat sinks: They are made of aluminum finned radiators and do not possess any type of mechanical components. They dissipate thermal energy by using the convection process. In comparison to active heat sinks, they are more reliable and for efficient operation, there is an immense need to maintain the continuous flow of air across their fins.
Swaged heat sinks: They have limited airflow management, medium performance and inexpensive.
Single fin assembly heat sinks: They are light in weight and can be easily installed in tight spaces. It can be used for a wide range of applications.
Forged heat sinks: Compressive forces along with aluminum/copper metals are used to form heat sinks.
Folded fin-heat sinks: Posses fold heat sink material and have an extremely large surface area. They have incredibly high-heat flux density and high performance. This is exorbitant because the cost of ducting and manufacturing is also involved.
Striking features of heat sinks:
- The heat sink is certainly a passive heat exchanger and the heat sink manufacturer has designed it in a manner that has a large surface area that comes in contact with the surrounding media like air. The electronic parts that are not enough to moderate the temperature require heat sink for cooling.
- It maintains the thermal stability of electronic components and the performance entirely depends on factors like velocity, surface treatment, protrusion design, and choice of material.
- The graphic processors and CPUs of computers are also cooled down by using the heat sinks. Heat sinks are also known as heat spreaders which are typically used as covers on a computer’s memory to spread the heat.
- Over-heating can be avoided.