Q:  Why is copper based heat sink better than aluminum based solution?
A:  The short answer to the question is the fact that copper conducts heat better than aluminum. Engineers utilize thermal conductivity (W/m*K) value to measure the effectiveness of a material. In this case, copper has a thermal conductivity of ~401 W/m*K and aluminum is ~237 W/m*K. To put it in perspective, wood has a thermal conductivity value of 0.04 ~ 0.4 W/m*K and concrete is 1.7 W/m*K, that is why wood does not get quiet as hot as concrete on a hot sunny day.