A heat radiation structure of an electric parts assembly, a heat conduction sheet, and a method of manufacturing an electric parts assembly are provided that are capable of reducing a gap between neighboring separate sheets after sheet compression while minimizing an unintentional increase in sheet reaction force. A heat conduction sheet (101A) disposed between a cooler and a heat generating element includes a plurality of separate sheets (102), each of the separate sheets (102) includes a plurality of convex sections protruding circumferentially outward from the sheet and a plurality of concave section recessed circumferentially inward on an outer circumferential edge of a shape when seen in a plan view in a state before being pinched between a cooler and a heat generating element, and the convex sections and the concave sections are disposed to be arranged alternately in a circumferential direction of the separate sheets (102) in a shape when seen in a plan view. When the plurality of separate sheets (102) are pinched between the cooler and the heat generating element, the gap between the neighboring separate sheets (102) is reduced by changing a shape of the outer circumferential edge of the plurality of separate sheets (102) to fill the neighboring concave sections.