A chip is embedded in a substrate where there is cooling from above only. The bo

Question

A chip is embedded in a substrate where there is cooling from above only. The bottom of the substrate may be considered a perfect insulator. The terminals shown provide electric power to the chip via two connecting (+) and (-) conductor traces. The generation of heat within the chip is known to be 0.225 Watts. Cooling of the chip takes place via convection from the chip to a fluid (which resides just above the chip). The ambient temperature of the fluid is 20 degree C. The operating temperature of the connecting (+) and (-) conductor traces is the same as the chip. The heat transfer coefficient for convection between the chip and the coolant is 150 W/m2 - degree K. Assuming there is no heat transfer between the bottom of the chip and the substrate, what is the surface temperature of the chip in degree C? Surface AREA of chip ,4 mm (H),5 mm(w), 15 mm(D)

Explanation / Answer

for steady state we can balance
heat generated = heat lost by convection to fluid

therefore
0.225 = h*A*(Ts - 20)

A has to be calculated for all the five exposed surfaces

A = (5*15)+(2*15*4) +(2*5*4) = 235 mm2 = 235 * 10-6 m2

now

0.225 = 150 * 235*10-6 *(Ts - 20)

From here Ts = 26.38 0C

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.