Abstract This investigate is designated to the viewpoint that arrangement array of multichip modules are both staggered and in-line. Moreover, here we will discuss and compare the effects and differences of the relevantparameters caused by change Reynolds number (Re) in the experiment.In this experiment, I adopt ¡§transient heat transfer method with thermochromic liquid crystal¡¨ to research multichip modules array change to 3 ¡Ñ 5 and in-line or staggered multichip modules array to probe into the effects of over high density electronic multichip array space to length ratio to heat transfer effects when over high density electronic multichip array space to length ratio are S/L= 4/20,6/20,8/20 in the 8mm¡B12m¡B16mm respectively. The conditions are as following when every row center of chip convection heat transfer coefficient are measured: standard height to length ratio is H/L=10/20 and the height is 20mm. By observing the relationship of the varying parameters, as we can see in the analyze multichip of the experiment Re range form 1394 to 5025, we are able to improve thermal management. The experimentresule: (1) At higher values of Re the heat transfer effects are gain more,atteribute main flow field separation and reattachment is form behind the downstream modules. (2) In over high density multichip array 12S (S/L=6/20) proper are use for Re higher 4135 more than, at 8S (S/L=4/20)the lower Re can be thermocumulate in chip center. (3)When Re is 4135~5025,the heat transfer effects from staggered array is superior to in-line array. If Re range is 1394~3210,the thermal conduction is opposite. Therefore, Re is still the key that decides the efficacy of over high density electronic multichip array heat transfer effects.