Many times we forget about it, but it is a fundamental component. The thermal paste is used in any personal computer at present, as well as in many other devices that use any processor.
Today we are going to dedicate a special with everything you need to know about thermal paste. What it is used for, what it is made of and why it is necessary to take care of it and renew it periodically. A vital putty for our computers to stay alive for many years.
What is thermal paste?
The thermal paste is a putty that can be presented in multiple formats, where the most common is a very dense and thick liquid. It usually has a metallic color due to its components, although other variants have a white hue.
The main characteristic of the thermal paste is to offer a high thermal conductivity, reason for its use: it is applied between the upper surface of the processor and the contact surface of the dissipator. Its purpose is to “move” the heat of the first component to the second. Still, also, since we usually talk about metal surfaces, some irregularities are covered by the paste to achieve better contact between both parties.
In short, the purpose of the thermal paste is to serve as a physical intermediary between the processor (usually CPU, but also other chips) and the dissipator, so that the heat generated by the first can move along the thermal paste and get to the second that, through its fans, will send it abroad.
Thermal paste components
Although this section is more a chemical than electronics or hardware, we will give a few small brushstrokes on what is the composition of the thermal paste.
First of all, it is necessary to discriminate between the different types of thermal paste, among which we could say that two of them are the most common: those based on ceramic components and those based on metallic elements.
The first, thermal ceramic pastes, are characterized by having a whitish color. Its composition is based on ceramic powder suspended in a mixture of liquid, usually a kind of silicone. It is a cheap and basic thermal paste that is generally available for sale in stores specializing in electronics. However, I would not recommend its use in computer components because the temperatures that collect the hardware components of a computer are usually exaggeratedly high.
Because of this, something else is needed, and here comes into play the second type: the metallic thermal paste. Like the ceramic, it starts from a base of a kind of silicone to which metals such as aluminum or silver are added, which offer much higher thermal conductivity than ceramics. They are more expensive, but ideal to withstand the high temperatures of a computer chip.
There are many other types of thermal paste, although these two are the most common here. It is also possible to find the thermal paste of any of the two models with glue; nothing recommended to serve next to the heatsink and a computer processor.
Reasons to take care of the thermal paste of your computer.
Any desktop computer or current laptop uses thermal paste, which, although we have never seen it, is hidden behind the CPU cooler. The same goes for the graphics card, where the GPU (Graphics Processor Unit, similar to the CPU but on the graphics card) needs this vicious element to conduct the heat to the fan and dissipator. And I do not forget some chipsets that in specific models of motherboards also use a small heatsink (active, i.,e. with fan, or passive) to extract heat.
CPU, GPU, and chipset, these are the three elements of a home computer that usually use thermal paste that, having a liquid base (somewhat viscous, as I said above), have a small part of the water that can evaporate with the step of time and lead to a solid mass. Generally, it usually happens after several years of use, although depending on the circumstances and the quality of the thermal paste, it can also be something before.
This solid mass completely breaks the purpose of the thermal paste, which is to fill in the gaps between the processor and the dissipator and that appear over time, due for example, to the expansion and contraction of the materials with the changes of temperature. It is, therefore, important that the thermal paste is in perfect condition throughout its life.
If a thermal paste is in good condition, it will provide good thermal conductivity between the processor and heatsink, causing the heat to move correctly to the second. If it is in poor condition, the weather will remain in the processor, causing overheating that sometimes limit the malfunction of the chip and even its physical deterioration. For example, the physical limits of a CPU are between 95 and 110 degrees Celsius, at which time the manufacturer does not guarantee what can happen to the chip from a physical point of view. The most usual is that the internal circuits will burn due to intense heat, having to throw the component away.
How to apply the thermal paste in the processor
Now that we know what the thermal paste is and its use. Let’s now understand how to use it in the best way to assemble our processor or graphics card.
We will start by warning that it is not necessary to be a professional to assemble a computer. However, basic knowledge is required because the bad connection between components can damage or leave the equipment in malfunction, but with our steps, you will not have any problem.
As we have already mentioned, the thermal paste will be used to control the heat that may exist between two components, that is, that will optimize the heat inside the equipment, dissipating the “high” temperatures that can be generated when turning on our computer. That is why we must select the pasta that will help us meet our goals.
There are different types of pasta classified according to their material:
- Metal thermal paste: they are the most expensive. However, they provide better heat conductivity. Usually, its components include silver, gold, and copper … this would be our best option.
- Thermal silicone paste: it is of lower quality, and its price is lower than metal paste. Ideal for graphics cards.
- Ceramic thermal paste: it is even cheaper, but they lose their functionality in a shorter period than silicone or metal.
- Liquid thermal paste: It has become quite famous when used to make delidded in the Intel Mainstream processors (Skylake, Haswell, Ivy Bridge …), and when removing, it is difficult to clean.
We recommend the use of non-conductive thermal paste. Why do you use non-conductive? They are delicious and avoid any problem with the equipment. For the application, two steps are required, prepare the surface, and apply the thermal paste. Now we will explain it to you in more detail.
1) Prepare the surface of the components:
Clean the surface of the parts, using isopropyl alcohol. Do the task with a little cotton, and with gentle movements, be patient that you will have your reward.
Optional (Not advisable when losing the warranty): Some users appear the surface with sandpaper of fewer than 180 grains, and as with cotton and alcohol, this process must be with smooth movements; this technique will also allow having uniform surfaces that they contribute in the dissipation of heat. However, this option is not recommended, because we can lose the warranty of the processor, by dropping the batch and screen printing of it.
2) Apply the paste:
There are two places where we can apply the thermal paste, one of them is on the heat sink and the second on top of the processor. Still, the most effective is the second option. The way to apply it is by drawing two lines in the form of “X” (Recommended for the socket X99 or LGA 2011-3) or a straight line “|” (For socket LGA 1151 or Z170), since this way you will have more surface covered by this paste and will reduce the air bubbles between the components.
Then we begin to join the pieces, for this, we must stick the heat sink making pressure simultaneously on all sides of the component to expand the paste on the entire surface leaving a thin layer, it is essential to know that once the parts are glued, we can pick them up because the work would be lost. We would have to prepare the surfaces again as in point one.
Once done these two simple steps, we will mount the fans and the cable of each fan to the motherboard. Regularly the processors usually work with an average temperature of 30ºC at rest and a maximum of about 60ºC. Everything will depend on the socket, heat sink, and cooling of your box. Doubts? Ask us.
It is essential to know that many thermal pastes need a “cure” time, that is, the Arctic Silver 5 needs up to 200 hours (several days) to get the most out of it. While the MX4 its instant effect and is the pasta we most recommend.
How to know if the thermal paste is in good condition and how to change it?
Difficult question if we do not want to get our hands dirty. The simplest thing we can do is monitor the temperatures of our computer, taking into account the ambient temperature and studying the increases produced overtime under the same circumstances: the laptop turned on for half an hour and without running any process, for example, with the fans running at minimum revolutions and with a fixed ambient temperature.
However, this is usually a somewhat tedious task that requires us to be attentive for many months to take temperatures, store, and organize them. It is much easier to replace the thermal paste every so often, for which you only need a screwdriver (usually a star, almost all the screws of a computer have the same head), some patience, and a bit of skill.
The method or process for a central processor or CPU is as follows:
- The computer’s side cover opens. It has no loss, although be careful with some models of boxes that have a fan that carries a cable inside the box.
- The heatsink is removed. This point is one of the most delicate since the dissipator may use screws or flaps under pressure. In any case, if you have no experience, it is advisable to go to the official website of the dissipator manufacturer to study the method to follow.
- Once the heatsink has been removed, we will have separated it from the motherboard. You can also remove the processor, removing it from the motherboard with care (some models have pins that bend with the look).
- With the processor and the heatsink on the table, we rest them on a padded surface like a dry cloth or a towel. It is not advisable to use hard surfaces to avoid possible problems due to an unexpected blow.
- Now, carefully, all traces of the thermal paste of both the CPU and the dissipator are cleaned. For this, alcohol and toilet paper can be used, always taking care not to hit or modify the structure of both components and eliminating the remaining thermal paste of any nook.
- Once both components are cleaned, they are thoroughly dried (again, carefully), and a new thermal paste is applied. For this, it is necessary to cover the contact part of the dissipater with a thin layer of thermal paste, usually one millimeter or less. It is essential to mold the dough until it is regular, for example, with the help of a wooden stick or a small piece of paper, using it as a spatula.
- Once the new thermal paste is applied, it is necessary to reassemble all the parts. Note that the processor has only one possible position in the socket (usually marked in one of its corners) and has to enter without any pressure. If we have reinstalled the CPU on the motherboard, we must be careful not to move the processor to avoid spilling thermal paste on other areas of the motherboard.
It is always advisable to replace the thermal paste in case of removing the dissipator since when moving it, we will be changing the position of the previous dough, and this can lead to areas that are not entirely covered by the material. I should also mention that the method described above is not unique or universal and that each teacher has his booklet here. For example, some people apply a layer of paste to the heatsink and another to the processor. However, I prefer to give only one so that when the heatsink is placed (usually under pressure), it does not overflow to the motherboard.
Regarding the time of replacement of the thermal paste, everything will depend on the quality of the same, the ambient temperature, the operating time of the computer, the percentage of CPU utilization, and some other reason. I recommend replacing the thermal paste every year, although the manufacturers of the suitable adhesives usually guarantee proper operation in periods of between three and five years.
Finally, although we have focused on the central processor or CPU, both GPU and chipset (and it is possible that other components) use thermal paste and it is advisable to replace it. For this, we will follow a process similar to the one described above for the CPU: we will separate the chip from the metallic dissipater, we will clean the existing remains, we will apply the new paste, and we will reassemble it.
Conclusions
Computers are heat stoves produced by their chips, and that heat has to be removed in some way. For this, the heatsinks are very helpful and, together with the fans, extract the hot air to the outside of the box.
But between the chips and the dissipators is the thermal paste, a somewhat thick and viscous liquid component that is generally one of the forgotten ones in our computer. It is of great importance that the thermal paste is in good working order since it is in charge of “moving” the heat towards the heatsink, which, in turn, is the one that takes it outside. I recommend replacing the thermal paste every year in a generally straightforward process, but in which we will be dealing with fragile components with which we must take the utmost care.
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