Heat is the enemy to beat . The “coconut” of integrated circuits in general. And of the microprocessors in particular . If it increases in excess it can cause the stability and performance of a computer to plummet, but the worst is not this. The most serious thing is that an excessive temperature can trigger physicochemical processes capable of permanently damaging a microprocessor.
Fortunately, we have tools designed to prevent these unwanted effects from occurring. Cooling by fans is the most used and usually gives very good results, but there are other options that users are familiar with , such as, for example, steam chambers or liquid cooling systems . The latter are the protagonists of this article. Installing one of them on a PC is relatively simple, and, in addition, its price has been greatly reduced in recent years, so it is worth knowing what impact they can have on the performance and life of our computer.
In order to understand why it is important to properly cool the components of a computer and what mechanisms are involved in this process, it does not even appear to briefly review the effects of convection and heat conduction . A part of the electrical energy that an integrated circuit requires to carry out its function is dissipated in the form of heat, and that thermal energy must necessarily be transported outside the core of the integrated circuit to prevent the transistors it contains from exceeding its maximum threshold Of temperature.
A part of the electrical energy that requires an integrated circuit to carry out its function dissipates in the form of heat and must be evacuated to prevent its temperature from increasing excessively
The power that dissipates a microprocessor in the form of heat depends on several factors , but the most relevant are the voltage it requires, the number of transistors that it incorporates, the clock frequency at which it works and the integration technology that has been used in its manufacture It is easy to intuit that if it contains more transistors it will need more energy to work, and this increase in the electrical energy it receives will also cause an increase in the energy that dissipates in the form of heat. In addition, increasing the clock frequency means that the microprocessor carries out more operations at the same time, so that the transistors will change state more frequently, consume more energy and dissipate more heat.
The impact of the number of transistors and the clock frequency on heat that dissipate such complex components as a microprocessor or a graphics processor is enormous. But the real challenge lies in the need to prevent its temperature from rising to the point of causing the chip to stop working properly or even end up damaged. The first symptom of overheating usually takes the form of equipment crashes, unexpected restarts and, ultimately, an abnormal behavior of both the operating system and applications. And if the heating persists the processor can be irreparably damaged.
Fortunately, the development of integration technology is a very valuable tool that allows us to introduce more transistors in the core of integrated circuits. And this is possible because, roughly, it helps us reduce both the size of the transistors and the distance that separates them. This reduction in size has a beneficial effect on the amount of energy they need to work, which helps us keep the semiconductor temperature under control. But, at the same time, it can also cause the appearance of electromigration . And this is one of the factors that explain why if the temperature of a microprocessor increases beyond its maximum threshold it can be damaged.
Electromigration is a physicochemical phenomenon that causes material degradation.of the semiconductor as a result of the working temperature it reaches and the current density that circulates through it. A priori, as we have seen, that the structures of a microprocessor are smaller is beneficial because it allows us to introduce more transistors. This improvement has a positive impact on performance and is a useful tool in keeping the chip consumption and temperature under control. But, at the same time, the proximity of these structures and their minimum size leads to the appearance of electromigration, especially when reaching high temperatures, which explains why semiconductor manufacturers currently devote many resources to the design of technologies capable of mitigating this effect.
The most effective strategy in preventing the overheating of a complex integrated circuit is to transport the energy that dissipates in the form of heat to other solid or gaseous objects that are in contact with it. To optimize this process, microprocessor manufacturers place a metal heatsink on the surface of the chip, which is precisely responsible for extracting the heat dissipated by the semiconductor core. The problem is that that heat must be transported somewhere. And, in addition, with the necessary efficiency to avoid that the temperature increases more of the account. This is where convection and conduction mechanisms come into playof which I have spoken in the first lines of this section, which are essential to help us understand the role of our computer’s cooling systems.