| 摘要 |
The purpose of the present invention is to provide a heat sink for an in-vehicle LED lamp, which is capable of efficient heat dissipation by radiation. The heat sink includes a substrate to which an LED element is attached, and a plate-shaped heat dissipating surface integrally and continuously formed with the substrate around the LED element. The substrate and the plate-shaped heat dissipating surface are formed of aluminum or an aluminum alloy having a specific thermal conductivity λ and a specific surface emissivity ε. When the plate thickness of the substrate and the plate-shaped heat dissipating surface is specified in a range from 0.8 to 6 mm, a total projected area of all the heat dissipating surfaces of the heat sink is specified in a range from 19000 to 60000 mm^2 so as to obtain a heat resistance R of 4.0 (K/W) or smaller. Projected areas (P0, P1) of two plate-shaped heat dissipating surfaces (10, 11) of the heat sink in two different directions are sufficiently increased with respect to corresponding sectional areas of the substrate (2) so as to increase of efficiency of heat dissipation by radiation to the surrounding closed space therearound. |
