Lapping Guide
Have you ever heard of the term "lapping"? Lapping is the process of making a heatsink flat to achieve better metal-to-metal contact between the heatsink and the CPU die or chip, resulting in improved cooling performance. The goal is to reduce the size of microscopic valleys on the surface of the heatsink, allowing thermal compounds to work more efficiently.
In this guide, I will walk you through the straightforward process of lapping a heatsink of any kind.
Here's what you'll need:
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800 grit wet or dry sandpaper
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1500 grit wet or dry sandpaper
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A piece of glass
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Metal polish with a soft cloth
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Your heatsink (CPU, NB, etc.)
Metal Polish on the left...MOTHERS brand
This was before lapping...Since then the thermal compound is spread evenly
Step 1: Gather all the necessary materials and have them within reach.
Step 2: Place the 800 grit sandpaper on the piece of glass.
See how concave the heatsink is? It looks ugly
Step 3: Pour a small amount of warm water on the sandpaper. Take hold of your heatsink, apply consistent pressure, and start sanding in a figure-eight motion. Repeat this process or find a method that works best for you. The direction and technique are not critical.
During the lapping process, make sure to rinse the sandpaper and heatsink regularly. You'll notice that the base of the heatsink is concave, and paint may come off from different areas, indicating unevenness. Use your judgment to determine when to finish using the 800 grit sandpaper.
Finished with 800grit, bring on the 1500grit baby!
Step 4: Repeat the previous steps using the 1500 grit sandpaper. Continue sanding until you feel that the bottom of the heatsink is completely flat. Rinse the heatsink with water and simultaneously dry it. Be cautious not to touch the bottom of the heatsink with your fingers, as the oils from your skin can degrade performance.
After 1500grit
Step 5: This step is optional, but if you desire a mirror finish, apply some metal polish and rub it onto the heatsink.
Congratulations! You have successfully completed the lapping process. Enjoy improved performance and temperature decreases from your CPU or other components. Remember to apply thermal compound between the chip and heatsink.
After lapping, you may experience a temperature drop of around 1-5 degrees Celsius, although results may vary depending on your specific setup. If you touch the heatsink and it feels warm, it indicates that the heatsink is effectively absorbing and dissipating heat. Lapping is a worthwhile effort to maximize performance and cooling capabilities, and it's well worth the time and energy invested.
I hope this guide has been helpful. Happy lapping and enjoy the benefits of your newly lapped heatsink!
Here are some images of the mirror finish of my northbridge heatsink:
Say cheese!
Meet the top of my monitor.
