When considering the cooling of electronic components we can simplify the objectives as follows;

• Reduce the overall electronic function cost,
• Reduce the application’s required component rating,
• Increase the commutated power,
• Improved long term reliability.

To illustrate this, we consider the following example. An Electronic surface mount component is placed on the cooling device, as seen in previous schematic. If we define a coefficient of exchange, Heq, and a thermal resistance of the cooling device, Rhs as follows:

Heq =	P	(W/m2 °C)	Rhs = 1/Heq (°Cm2/W)
	----------------
	S(Tp-Ts)

To summarize: The higher the Heq the more efficient the cooling device. A higher Heq can bring success in reaching the objectives.

Table on the right shows a relative comparison of the HS Marston Solutions applying the Heq values. Also see each specific data sheet which indicates relative Heq characteristics.