Electronic radiator is used to control the junction temperature of semiconductor devices less than the maximum junction temperature. The radiator is generally made of materials with high heat conductivity. At present, the materials used for radiators in electronic products at home and abroad are generally aluminum, copper and iron. The most widely used is aluminum (heat conductivity 2.12w / cm ·℃). Copper has a high thermal conductivity (3.85w / cm ·℃), but it is not as low as aluminum. In some small electronic products, some radiators are made of steel. Although the thermal conductivity of steel is poor (0.46w / cm ·℃), its cost is low and it can be used in products with low requirements. Generally, the thicker the radiator material is and the larger the surface area is, the better the heat dissipation effect is. However, when the actual junction temperature is lower than the maximum junction temperature in the normal working state of semiconductor power devices, the varieties with small volume and few materials should be selected as far as possible
Radiator selection
1. The effect of radiator is closely related to the installation process. During installation, the contact area between power device and radiator should be increased as much as possible, the contact thermal resistance should be reduced, and the heat transfer effect should be improved.
2. It is recommended to use low thermal resistance materials, such as copper platinum, aluminum platinum or thin mica, polyester film, when heat conduction or insulation gasket is needed between the device and radiator.
3. When a device is installed, its mounting hole (or group hole) is placed at the center (L / 2) of the radiator base; when two or more spiral plate heat exchangers are installed, its mounting hole (or group hole) is evenly distributed (L / 2n) on the center line of the radiator base.
4. Ensure that the screw torque is the same when tightening the device.
5. After the power devices and radiators are installed, they should not be machined or reconditioned, otherwise they will produce stress and increase contact thermal resistance.
6. The single-sided fin radiator is suitable for natural air cooling outside the equipment (such as installed outside the case), which is not only conducive to the ventilation and heat dissipation of power devices, but also can reduce the temperature rise inside the machine.
7. During natural cooling, the cross section of radiator shall be parallel to the direction of horizontal plane; during forced air cooling, the flow direction of air flow shall be parallel to the direction of fins of radiator.
