Like a car engine, your computer sometimes gets hot, especially during heavy use. Just like a car, your PC has a built-in feature that protects it against overheating, and a thermal paste is one of those components. Keep reading to know what it does and how long the thermal paste lasts.
How long does thermal paste last in the tube?
The shelf life of whatever thermal paste you buy depends on the compound type and its storage conditions. Most market types will have an average shelf life of two years if the paste is stored in a cool, dry place and out of direct sunlight with its cap appropriately covered. To recognize a thermal compound that’s gone bad – it’s either going to be completely dried out, hard, or flaky.
So how long does thermal paste last in the CPU? Generally, thermal pastes have a lifespan of about 3 to 5 years under normal conditions. Usage heavily determines how much thermal paste lasts.
What is a thermal paste?
A thermal paste, also known as thermal grease, thermal interface material, or CPU grease, is a heat-conductive (but usually electrically insulated) chemical compound applied between a heat sink and the surface of the CPU (or whatever the heat source is).
The heat sink is the component that draws heat away from the CPU by conduction. It doesn’t have a microscopically smooth surface, with dents and gaps. These tiny gaps and dents trap air, making heat transfer between CPU and heat sink inefficient. The thermal paste creates an even, smooth point of contact between the heat sink and the heat source, filling in the dents and gaps that trap air, ensuring heat is drawn away from the CPU and dissipated more efficiently.
What is a thermal paste made of?
Thermal pastes are usually made of a polymerizable liquid matrix with a considerable volume of thermally conductive but electrically insulating filler.
A typical material for the matrices are epoxies, urethanes, silicone grease, acrylates like solvent-based systems, pressure-sensitive adhesive tapes, or hot-melt adhesives. Fillers for the adhesives are usually aluminum oxide, zinc oxide, and boron nitride, and aluminum nitride has been used more recently.
The metal oxides or nitrides act as the conducting materials, and the adhesives act as the carrying medium. As a result, silver thermal pastes have a higher conductivity rating. They are made of tiny micronized silver particles suspended in a ceramic or silicone medium. However, metal-based thermal pastes risk damaging the system if they flow into circuits since they are electrically conductive and capacitive.
How often should I replace the thermal paste on the CPU?
You should bear in mind that not all thermal pastes maintain the same level of effectiveness.
Most market options would last for two to three years, while higher-end thermal pastes can last up to seven years. Replacing it every two to three years is a good option and will keep your CPU at its optimum performance. The amount of usage will determine how long your thermal paste last.
How To Apply Thermal Paste – Step-By-Step
The most straightforward application method is to place a little pea-sized drop on the processor’s surface. Then gently attach the heat sink to the processor plate, equally applying pressure on the four corners. This ensures the thermal paste is spread evenly across the surface. If your thermal paste comes with an applicator, you can use it to spread the paste evenly. Some people prefer this method to ensure the paste is applied perfectly before clamping the processor’s heat sink.
There are even more intricate ways to apply the paste and the areas that span the processor’s cores. This would require knowledge of where the cores are, so this isn’t for everyone. However, if you’re still willing to get a more efficient thermal paste spread, follow the steps below:
There are four methods of application: Vertical Line, Horizontal line, Surface Spread, and Middle Dot.
For the Vertical Line method, these are the processors it works for:
2nd, 3rd, 4th, 5th, 6th, and 7th Generation Intel® Core™ i3, i5, i7, and i7 Extreme with Metal Cap · Previous Generation Intel® Core™ i3, i5, i7, vPro, and Extreme with Metal Cap · Previous Generation Intel® Core™ 2 Duo with Metal Cap · Celeron® Dual Core with Metal Cap · Xeon® Series: 5500, 5200, 5100, 5000, 3500 and 3000 with Metal Cap · Xeon ® Series: E7: 8800, 4800 and 2800 and E3: 1200, L3406 with Metal Cap.
For the Horizontal Method:
Core™ 2 Quad with Metal Cap · Core™ 2 Quad Extreme with Metal Cap · Pentium® Dual Core with Metal Cap · Pentium® D with Metal Cap · Xeon® Series: 7000, 5400, and 5300 with Metal Cap
For the Middle Dot method:
· Pentium® 4 Or Legacy Single Core with Metal Cap · Celeron® D or Legacy Single Core with Metal Cap · Xeon® Series: Legacy Core with Metal Cap
For the Surface Spread method:
· Any Intel® Mobile or Notebook CPU. · Any Intel® CPU without a Metal Cap.
Application Methods
Precautions
If your heatsink has thermal material or a thermal pad on it, the existing material or pad must be removed before applying the new thermal compound.
Only the new paste should be between the CPU plate and the heat sink. Do not use any petroleum-based cleaners or automotive degreasers on the CPU base cap or heat sink surface. Automotive oil is designed not to evaporate. It will fill the microscopic dents and gaps in the metal, significantly reducing the effectiveness of any subsequently applied thermal compound.
How to remove old thermal paste
Thermal pads are mostly paraffin wax that melts once it gets hot. As it melts, the wax fills the microscopic dents and gaps in the heatsink and plate of the CPU. Therefore, to prevent permanent contamination of the heatsink and CPU plate, the thermal pad should be removed from the heatsink before turning ON the computer.
Using heat or hot water to remove the pad is wrong, as the heat can melt the wax into the heatsink. Also, take care not to scratch the surface of the heat sink when removing the pad.
A plastic tool like a credit card can scrape OFF the thermal pad without scratching the metal surface. The remnants of the wax could then be easily removed with high-purity isopropyl alcohol or carburetor cleaner and a lint-free cloth (a lens cleaning cloth or a coffee filter).
If you use a xylene-based cleaner, always follow up by cleaning high-purity isopropyl alcohol.
Protect the surface from foreign materials and do not touch the surface after as hair, pieces of lint, dead skin cells, or oils can significantly affect the thermal conduction performance. For example, oils from fingerprints can be as thick as 0.005″ and can severely hinder performance by preventing the thermal conducting matrix or filler from directly touching the metal surfaces.
Vertical Line method
Applying Thermal Compound:
Place the nozzle of the plunger pointing down the midline of the CPU cap, and to the left, apply a 1 mm wide line of thermal paste approximately 3 mm from the borders on each side. The line crosses over the dual or quad cores of the processor. It is more effective to have the compound line over the cords of the processor than to have it all over the surface of the plate from end to end as heat passes directly over the chords. Below all the methods are procedures for attaching the heatsink.
Horizontal Line method
Place the nozzle of the plunger pointing down the midline of the CPU cap, and from top to bottom, apply a 1 mm wide line of thermal paste approximately 3 mm from the borders on the top and bottom sides. The line crosses over the dual or quad cores of the processor line in the vertical method.
Middle Dot method
In the middle of the CPU plate, apply a dot of thermal paste. Apply about 5 cubic millimeters of thermal paste (the size of 1 uncooked grain of white rice). The dot of thermal paste is directly above the middle of the core(s), and the same principles as the other methods apply.
Surface Spread method
Apply a blob of thermal paste to a corner of the CPU plate. The amount of thermal compound to apply depends on the surface area of your plate. For a small single-core CPU, use about 1-2 cubic millimeters, which is approx. 1/2 uncooked grain of white rice, and for a large single or multiple core CPU, use 4-5 cubic millimeters, which is approx. a raw grain of white rice.
Spread the thermal paste using the thin edge of a credit card or a single-edge razor blade as an application tool. You can use whatever tool you desire as long as it is clean and gives you control over the application thickness and area.
A flatter surface would require a thinner layer of thermal paste. Processors directly from the manufacturer sometimes have surface irregularities that will need about 0.003″ to 0.005″ of thickness to fill the microscopic gaps and dents. This is equal to about one sheet of standard weight paper. A properly spread thermal pate would have a translucent haze.
Attaching the Heatsink:
Don’t spread the line to dissipate the thermal paste after using the methods above, except for the surface spread method. Instead, gently place your heatsink on the plate and apply a little pressure. This would make sure the paste spreads evenly, with no bubbles underneath. Then, twist the heatsink sideways about one or two degrees to properly apply the paste. Note that some heatsinks can’t be rotated once attached.
Once you’re done, turn ON your computer to see how well it functions.
Read also: How Long Does A Gaming PC Last?
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