What is the necessity of applying thermal double-sided adhesive on aluminum substrates?

A：
Of course, the aluminum substrate has already handled the connection from the LED to the circuit using the aluminum plate as the substrate. The heat can be transferred to the aluminum plate, but unfortunately, this aluminum plate is often not the final heat sink. Usually, this aluminum plate must be connected to The simplest door diameter is to connect the radiator with a rivet or screw. However, this door diameter often forms an air gap, and the thermal resistance established by a small air gap will be dozens of times greater than the other. .Because the thermal conductivity of air is 0.023W / m · k. Therefore, thermal conductive glue must be applied to fill the gaps. The thermal conductivity of ordinary thermal silica gel is roughly 1-2W / m · k. But the thermal paste must be flowable, Otherwise, an air gap will still be set due to uneven application, which may be worse than not necessary. Another disadvantage of thermal paste is that its own viscosity is not enough to fix the aluminum substrate to the aluminum heat sink.

Therefore, another door diameter is a double-sided film with strong adhesion and thermal conductivity. This thermally conductive film is made of acrylic series materials with a sticky heat conductive sheet, which is a sticky and low heat resistant heat dissipation material What's more, it has thermal conductivity and flexibility, which can abut the uneven parts on the parts, thereby avoiding the retention of air gaps. The thermal conductivity of thermally conductive silicone sheets is usually between 2-3W / m · k. Its tensile strength can be Up to 8kg / cm2. Enough to bond aluminum substrate and aluminum heat sink. Withstand voltage up to 4KV / mm