1. Aluminum square fins (0.5 mm x 0.5 mm) of 10 mm length are provided on the surface of an electronic device to carry 45 mW of energy generated by the device. The temperature at the surface of the...

1. Aluminum square fins (0.5 mm x 0.5 mm) of 10 mm length are provided on the surface of an electronic device to

carry 45 mW of energy generated by the device. The temperature at the surface of the device should not exceed

80°C, while temperature of the surrounding medium is 40°C. Assume
k
for aluminium = 190 W/(mK),
h
= 12W/

(m2K). Find the number of fins required, neglecting heat loss from the end of the fin.

2. An aluminum fin, 0.5 mm square and 1cm long, is attached to a semiconductor device to provide additional

cooling. The base of the fin can be assumed to be at the inside temperature of 80°C. Find the cooling capacity

provided by the fin. Ambient temperature = 40°C,
k
= 177 W/(mK),
h
= 12.44 W/(m2K).