The metal block comprising the composite body obtained in the above-described step was cooled to room temperature, after which, cutting with a wet band saw was performed to take out a 120 mm×70 mm×5 mm tubular aluminum-silicon carbide composite body comprising a composited portion comprising an aluminum alloy and silicon carbide and hole-formation portions comprising an aluminum alloy and aluminum short fibers.

Impregnation for five blocks was performed as per the above-described method. Further, through holes having a diameter of 7.5 mm centered at positions of 7.5 mm from the periphery of the corner portions of the aluminum-silicon carbide composite were formed by machining. That is, the through holes were formed in the portions where the hole-formation portions were formed. Through the above-described steps, a heat-dissipating component having the shape of that illustrated in FIG. 2 was manufactured.

Concerning these heat-dissipating components, each was tightened and fixed to an aluminum plate having a size of 120 mm×70 mm×10 mm with holes of 7.5 mm in diameter at the four corners by using bolts and nuts. At this time, the tightening torque was set to 4, 8, 10, 12, and 15 Nm with a torque wrench.

Next, each of the heat-dissipating components was subjected to 300 cycles of thermal cycling in which one cycle was ?40 degrees Celsius for 30 minutes and 125 degrees Celsius for 30 minutes, then the attachment between the heat-dissipating component and the aluminum plate was released, and the four corners of the composite body were measured with an ultrasonic flaw detector (FS-Line manufactured by Hitachi Construction Machinery Co., Ltd.) in order to search for the presence or absence of flaws. The results thereof are displayed in Table 1.