The problem of heat conduction and heat dissipation is an important part of the current lighting design. It can also be said that if the heat conduction and heat dissipation problems are not solved during the design process, this product is a waste product! Moreover, the heat conduction problem is not solved, the heat sink is made. It is useless.
As a particularly important thermal conductive material, aluminum substrates have special requirements in the wiring process. The following is a discussion of the most common high-power LEDs in the industry to discuss the use of copper foil for heat conduction.
In the industry, the very common wiring method is as follows:
The heat generated by the LED is only transmitted to the aluminum PCB substrate by the same copper foil surface as the LED heat sink. The cross-sectional view is as follows:
If so, the thermal path can be interpreted like this:
LED heat sink-----thermal grease------- copper foil as large as heat sink ------ aluminum substrate insulation layer ------ aluminum plate ------- heat sink
It can be seen from the figure that the heat conduction path of the LED to the aluminum substrate is only the same as the heat sink of the LED.
If we change our mindset, we will design the aluminum substrate as follows, as shown below:
We all know that the thermal conductivity of copper is much larger than that of aluminum. We designed it so that the copper foil layer of the LED heat sink is as large as possible, and the heat conducted by the LED heat sink is fast on the copper foil layer. Conducted open, and then conducted to the lower aluminum plate, artificially increase the heat conduction path, will greatly reduce the temperature of the LED heat sink, as long as possible to extend the working life of the LED.