How To Properly Apply Thermal Paste - Instructions and Troubleshooting

On: Monday, October 26, 2015 Comment: 0 Hit: 626

This blog describes the step by step process of applying thermal paste, and how to troubleshoot common issues.

PakDukaan is the official distributor of Arctic Silver in Pakistan. Arctic Silver is one of the most popular manufacturer of thermal paste and adhesives.

Arctic Silver Thermal Compound – Vertical Application

The Arctic Silver Thermal Compound used in heatsinks in high powered electronic components, such as CPUs, is imperative for the dissipation of heat from the processor into the surrounding area. The thermal compound in the processors may often need replacing in order to improve the system’s performance and provide stability to the machine. The Arctic Silver thermal compounds can be applied by following these easy steps:

Step 1: Heatsink preparation

Before applying the new thermal compound, the old thermal material/pad must be removed. Only the new thermal material should be between the heatsink and the metal cap of the CPU. Therefore, use plastic tools to scrape off thermal pads, so as to not scratch the heatsink. In addition, make use of a xylene based cleaner, followed by high purity isopropyl alcohol and a lint free cloth to remove the remaining material.

It is important to note that petroleum based cleaners should never be used for the purpose of removing the existing thermal compound. The oil particles do not evaporate and fill the microscopic wedges in the valleys which significantly reduce the efficacy of the new thermal compound. Furthermore, do not use heat or hot water to remove the material/pad as the wax may melt into the heatsink.

DO NOT touch the surface after it has been cleaned. Even the smallest impurities can affect the performance of the thermal interface.  Therefore avoid touching the heatsink and protect it from dust and other small particles.

Step 2: CPU Preparation

The metal cap protecting the quad or dual cores of the CPU may or may not be covered in thermal material. If it is not, then cleaning is not required, however, it is highly recommended. If the metal cap is covered in thermal material, clean the surface with xylene based cleaner, followed by high purity isopropoyl alcohol and a lint free cloth.

Again, it is imperative to keep the surface clean. Therefore, avoid touching the metal cap and keep it protected from dust and other small particles.

Step 3: Tinting the Heatsink and the Metal Cap

To achieve maximum levels of performance in minimum time, it is advised to tint the heatsink and metal cap. For this step, the Arctic Silver thermal compound, an old credit card (or other flat plastic with a straight edge) and a lens cleaning cloth will be required.

Identify the area on the base of the heatsink that will contact the CPU cores once the heatsink is mounted. Squeeze a small mound of the thermal compound onto the centre of this area and by using a flat edge of the plastic tool, work the paste back and forth in every direction to smooth out the compound. This process ensures that the microscopic crevices in the metal surface contacting the CPU are adequately filled.  

After the thermal compound has been thoroughly worked into the surface of the heatsink, remove the excess compound by wiping it away with a coffee filter or a lint free cloth. DO NOT use any solvent or fluid to clean the surface or the process will have been reversed.

Repeat the same procedure with the metal cap. Avoid touching the compound on the metal surfaces.

Step 4: Applying the thermal compound and attaching the heatsink

Apply a thin line of the thermal compound (approximately 1 mm) vertically across the quad or dual cores. As heat from the CPU cores travel directly through the metal cap through the compound to the heatsink, it is much more important to have a good interface directly above the cores than it is to have the metal cap covered with compound from corner to corner.  Do not spread the line of the thermal compound out. Follow manufacturer’s instructions to reattach the heatsink. Once the heatsink is placed on top of the metal cap, the compound will spread out on its own, with minimum air bubbles and maximum coverage.

Once the thermal compound has been applied and the heatsink properly mounted, you may turn on the computer. It is important to note that due to the shapes and sizes of the thermally conductive particles in the Arctic Silver thermal compound, it may multiple thermal cycles for the interface to reach achieve maximum conductivity. This break-in period may take from 25 to 200 hours. The break-in will occur over the normal use of the computer as long as it is turned off from time to time and the interface is allowed to cool down. The Actual internal core temperatures will also drop significantly during the course of the ‘break-in’.

Troubleshooting:  

When someone gets temperature results that are the opposite of the results achieved by hundreds of thousands of other users, the problem can usually be traced to one of 12 things listed below:

1. The heatsink was cleaned with an oil based cleaner which filled the microscopic gaps and contaminated the interface.

2. The existing thermal interface material was not completely removed. The compound should be the only material between the heatsink and the CPU.

3. The heatsink was not installed properly.

4. The thermal compound was applied too thick.

5. The measurement is being taken on the cold side of the thermal junction or on the side of the core where thermal compound squeezed from the junction contaminates the probe. (Better compound then transfers more heat to the probe so the temperature reads higher.)

6. The measurement probe moved when the chip was removed to clean off the previous compound.

7. The compound was not allowed to go through its break-in period. (Minimum 25 hours. Can be 400+ hours.) Temperatures will drop 1C to 5C over this time.

8. The application was contaminated with an eyelash, a bit of dirt, fingerprint or something else that spaced the heatsink away from the metal cap.

9. An unbalanced heatsink fan is causing excessive vibration and damaging the interface layer.

10. An improperly manufactured or bent shim is interfering with proper contact between the CPU core and the heatsink.

11. The heatsink fan was not plugged back in after the compound was changed.

12. The ambient temperature where the computer is located has changed. If the room temperature changes, the CPU temperature will also change. It is important to remember that cooling solutions keep the CPU X number of degrees above ambient. So if the ambient temperature increases 3 degrees, the CPU temperature will also increase 3 degrees.



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