poking around in led forums etc, I came across this article. From my experience with high performance computers, TIM paste is the most effective thermal interface material anyway. Pads are simply easier to use. Now there is an even better reason NOT to use them:
Aluminum Coupled to Carbon Composite
Aluminum alloys are extremely vulnerable when they are coupled to a carbon composite. Figure 3 shows the anodic and cathodic polarization curves of aluminum alloys and carbon composites, respectively. It is clear that the rate of galvanic corrosion in seawater is controlled by the oxygen reduction reaction. What this means is that any condition that leads to an increase in the rate of oxygen reduction will cause an increase in the rate of galvanic corrosion. During the galvanic corrosion, a white, jelly corrosion product will be formed on the surface of the aluminum.
There is an assertion that the galvanic corrosion rate of aluminum could be mitigated by the anodization of aluminum and the formation of a thick, protective aluminum oxide layer on the surface. However, it has to be mentioned that in the case of a breach of the oxide layer by mechanical damage, the situation becomes much worse because of really high cathode-to-anode surface area ratio.
Aluminum Coupled to Carbon Composite
Aluminum alloys are extremely vulnerable when they are coupled to a carbon composite. Figure 3 shows the anodic and cathodic polarization curves of aluminum alloys and carbon composites, respectively. It is clear that the rate of galvanic corrosion in seawater is controlled by the oxygen reduction reaction. What this means is that any condition that leads to an increase in the rate of oxygen reduction will cause an increase in the rate of galvanic corrosion. During the galvanic corrosion, a white, jelly corrosion product will be formed on the surface of the aluminum.
There is an assertion that the galvanic corrosion rate of aluminum could be mitigated by the anodization of aluminum and the formation of a thick, protective aluminum oxide layer on the surface. However, it has to be mentioned that in the case of a breach of the oxide layer by mechanical damage, the situation becomes much worse because of really high cathode-to-anode surface area ratio.
