A high‐brightness LED is overheating, and it is proposed that a 1‐mm thick spacer of copper—selected for its high thermal conductivity— should be added between the LED and the ceramic substrate. Using...

A high‐brightness LED is overheating, and it is proposed that a 1‐mm

thick spacer of copper—selected for its high thermal conductivity—

should be added between the LED and the ceramic substrate. Using the

1D heat‐transfer model shown in Figure 8.19, what is the temperature

change with and without the copper spacer? Note that: (1) the LED dissipates 1W of heat; (2) without the copper spacer, the total thermal resistance from the LED to the heat sink at Ts

is Rt=10K/W; and (3) the

spacer is the same size as the LED (1mm×1mm). What is the optimum

thickness for such a spacer? Is there a way to modify the spacer to

improve the temperature change?