Heat Sink Lapping
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As processors get more powerful they produce more and more heat as a byproduct of all the increased ability. As a response to this increased heat a number of advanced methods have been developed to combat this byproduct. Water-cooling, high tech thermal transfer pastes using exotic compounds like silver, and super powered fans have emerged as solutions to this heating problem. However, not always is the latest and greatest and newest technology going to be the only way to overcome your heat buildup blues.
A very basic method to increase the efficiency of the heat transfer from your processor to your heat sink is lapping it. Lapping is the process of gradually smoothing a surface until it is perfectly flat. The question is: why would I do this and how do I do it?
The reasons for heat sink lapping are varied and supported by a variety of claims and statistics throughout the internet. One of the most often repeated claims is that heat sink lapping can reduce the heat of your processor by up to 5 degrees Celsius.
How does it work?
Heat sinks are typically produced in a dye by a manufacturer and are shipped as a finished unit, sans fan and retaining clip. This casting process is done as a fast and fiscally efficient method of producing heat sinks for chip manufacturers. Naturally with the speed of the process and the volume associated with it certain manufacturing liberties are taken.
For example, the bottom of a typical aluminum heat sink is not flat. Rather, it is flat but not perfectly flat. It is because of this imperfection in flatness found in cheaper stock heat sinks that thermal grease is often applied before the product is shipped. Copper heat sinks, on the other hand, come prelapped and do not require lapping.
Thermal grease is meant to even out the contact between the processor and the heat sink for proper heat transfer. Additionally, heat sinks are often left with pits, grooves, and bumps in their surfaces from the casting processor. Thermal grease helps to fill in these small striations in the surface of the aluminum to allow near perfect heat transfer to occur.
Thermal grease, however, becomes less effective over time. The grease often has a tendency of drying out as the heat from the processor, especially processor’s that have been overclocked, accelerate the lifespan of the grease. This drying out greatly affects the efficiency of the heat transfer from the processor and over time can cause system instability and can cause processors to burn out as they start to overheat from the reduce cooling that dried out thermal grease causes.
Lapping the heat sink removes all these small imperfections in the heat sink to allow greater contact from the heat sink to the processor. If done properly and thoroughly the heat sink is often left as a shiny reflective mirror of polished aluminum that does not require the presence of thermal grease.
Next: How Do I Lap My Heat Sink? >>
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