Notes on the use of heat sink

1. In the calculation can not take the device data in the comparative power consumption value, but according to the actual conditions to calculate; data in the comparative junction temperature is generally 150 ℃, in the design of the margin to take 125 ℃, the ambient temperature can not take 25 ℃ (to consider the summer and the actual temperature of the chassis).

2. The installation of the heat sink should consider the direction conducive to heat dissipation, and to open the corresponding location on the chassis or case heat sink hole (so that the cold air from the bottom to enter, hot air from the top to dissipate).

3. If the housing of the device is an electrode, the mounting surface is not insulated (not insulated from the internal circuit). Mica gaskets must be used to insulate the mounting to prevent short circuit.

4. The pins of the device should pass through the heat sink and holes should be drilled in the heat sink. To prevent the pins from touching the wall of the hole, a PTFE sleeve should be applied.

5. In addition, different models of heat sinks have different thermal resistance under different heat dissipation conditions, which can be used for design reference, i.e., in the actual application can be calculated with reference to the thermal resistance of these heat sinks, and can use similar structural shape (cross-sectional area, perimeter) of the profile composed of the heat sink to substitute.

6. In the above calculation, some parameters are set, and the actual value may be different, the size of the substitute model is not exactly the same, so in mass production should be made to simulate the test to confirm whether the choice of heat sink is appropriate, if necessary to make some corrections (such as the length of the profile size or change the profile model, etc.) before mass production.