PROBLEM 4.31 KNOWN:Dimensions of chip array. Conductivity of substrate. Convection conditions. Contact esistance. Expression for resistance of spreader plate. Maximum chip temperature. rFIND:Maximum chip heat rate. SCHEMATIC:ASSUMPTIONS:(1) Steady-state, (2) Constant thermal conductivity, (3) Negligible radiation, (4) All heat transfer is by convection from the chip and the substrate surface (negligible heat transfer from ottom or sides of substrate). bANALYSIS:From the thermal circuit, ()hhhsph,cnvt,csp,cnvtspTTqq qRRRR∞∞−−=+=+++( )111222h,cnvs,hhRh AhL100W / mK 0.005m400K / W−−−⎡⎤===⋅=⎢⎥⎣⎦()357rrrrsubh1 1.410A0.344A0.043A0.034A1 0.353 0.005 00R0.408K / W4kL4 80 W / m K0.005m−+++−+++⋅=42hR0.5 10mK / WR2.000K / WL0.005m−′′×⋅=( )112sp,cnvsubs,hRh AA
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This note was uploaded on 12/07/2010 for the course MAE Heat Trans taught by Professor Lee,j.s. during the Spring '10 term at Seoul National.