Thermal Basic Theory
Conduction :
Factors : Material, Thermal Resistant and Quantity of Interface, DistanceˇK
Convection :
  Factors : System Impedance, CFM, Pressure , SpeedˇKˇK
Radiation :
  Factors : Surface Color, Dissipation Area, Surface Coating LayerˇK
 
Cooler Selection
Mechanical limitation on MLB keep out area of processor mounting.
According to processors mounting structure to select right cooler.
Low thermal resistance, high CFM and pressure and low noise.
PC system air flow direction vs. cooler air flow direction relation.
Cooler's mounting force and stable location on processor normal upper is
  need to be consider.
Clip mounting force must have reliability and easy installation.
Fan spec. (Voltage, Current and Connector housing) of cooler need
  compatible to MLB power connector.
Heat dissipation capability need to meet processor thermal design power and
  pc system internal environmental operation temperature.
Heat Sink bottom skin must be flat and finished.
Performance vs. Cost vs. Quality.