Pressure Drop Characteristics of Circuit Board with Arrays of LSI Packages

Experimental investigation was performed to study the pressure drop characteristics of parallel-plate channels where model packages of various sizes are mounted. The ratio of channel height to package height and placement pitch to package height are 1.3∼2.7 and 1.8∼5.6 for packages without fins, and 1.2∼2.0 and 2.1∼3.4 for finned packages, respectively. A new flow model is proposed which incorporates the three-dimensional nature of wakes behind the packages. The predicted values of pressure drop based on this model correlate with the experimental results within ±20∼30%.