(Solved): Problem: Chips of width \( \mathrm{L}=20 \mathrm{~mm} \) on a side are mounted to a substrate that ...

Problem: Chips of width \( \mathrm{L}=20 \mathrm{~mm} \) on a side are mounted to a substrate that is installed in an enclosure whose walls and air are maintained at a temperature of \( T_{\text {sur }}=20^{\circ} \mathrm{C} \). The chips have an emissivity of \( \varepsilon=0.80 \) and a maximum allowable temperature of \( T_{5}=75^{\circ} \mathrm{C} \). If heat is rejected from the chips by radiation and convection, what is the maximum operating power of each chip? a fan is used to maintain airflow through the enclosure with \( \mathrm{h}=250 \mathrm{~W} / \mathrm{m}^{2} \cdot \mathrm{K} \). You may assume that \( \mathrm{T}_{\mathrm{f}} \) \( =25^{\circ} \mathrm{C} . \)