PCB aluminum-based copper clad board is a metal circuit board material composed of copper foil, thermally conductive insulation layer and metal substrate. Its structure is divided into three layers:
Cireuitl. Layer circuit layer: It is equivalent to the copper-clad board of ordinary PCB.
Insulating layer: Insulating layer is a kind of low thermal resistance thermally conductive insulating material. Thickness: 0.003 "~ 0.006" inches is the core calculation method of aluminum-based copper clad laminates, which has been recognized by UL.
Base layer: It is a metal substrate, usually aluminum or copper. Aluminum-based copper-clad laminates and traditional epoxy glass cloth laminates. The PCB aluminum substrate is composed of a circuit layer, a thermally conductive insulating layer, and a metal base layer. The circuit layer (ie copper foil) is usually etched into a printed circuit to connect the various components of the module. In general, the circuit layer needs a large current carrying capacity, so a thick copper foil should be used, and the thickness is usually 35 μm to 280 μm. The thermal insulation layer is the core technology of the PCB aluminum substrate. It is usually filled with a special ceramic made of a special polymer. Low thermal resistance, good viscoelasticity, resistance to thermal aging, can withstand mechanical and thermal stress. High-performance PCB aluminum substrates such as IMS-H01, IMS-H02, and LED-0601 use this technology to make them have good thermal conductivity and high-strength electrical insulation; a metal substrate is an aluminum substrate, and its supporting members require High thermal conductivity, generally aluminum plate, but also copper plate (copper plate can provide better thermal conductivity), which is suitable for conventional machining such as drilling, punching and cutting.
PCB materials have advantages that other materials cannot match. Suitable for surface mount SMT technology of power components. No radiator is needed, the volume is greatly reduced, the heat dissipation effect is good, the heat insulation performance is good, and the mechanical performance is good. No radiator is needed, the volume is greatly reduced, the heat dissipation effect is good, the heat insulation performance is good, and the mechanical performance is good.
Thermal conductivity: Thermal conductivity is also called thermal conductivity, thermal conductivity, thermal conductivity. It represents the physical quantity of the material's thermal conductivity. When the vertical distance of the isothermal surface is 1m and the temperature difference is 1 ° C, the heat (kcal) passes through the 1m2 area due to heat conduction within 1h. Its unit is kilowatt / meter. hour. [kw / (m.h.. ° C)] If the substrate material is required to have greater heat dissipation capacity, the substrate material used must have a higher thermal conductivity (thermal conductivity). If it is necessary to achieve thermal insulation through the substrate, the lower the thermal conductivity of the substrate used, the better the effect.
Thermal resistance of aluminum substrate: A quantitative description of the thermal conductivity of an object, which can be expressed by thermal conductivity or another characteristic parameter, "thermal resistance". Related monographs suggest that thermal conductivity is suitable for characterizing the thermal conductivity of homogeneous materials. As a base material composed of multiple materials, its thermal conductivity is more suitable for quantitative description of thermal resistance. In heat conduction mode, the difference in surface temperature on both sides of the object (called the temperature difference) is the driving force for heat transfer. The thermal resistance (Rr) is equal to this temperature difference (T1-T2) divided by the heat flux (P). Therefore, the smaller the thermal resistance of the substrate material, the higher its thermal conductivity.
Models and parameters of aluminum substrates: Aluminum substrates on the market are divided into three thicknesses of 1.0mm, 1.5mm and 2.0mm. The basic parameters are ordinary type and high thermal conductivity type. General type The general thermal conductivity is 1.0 or more (the base thermal conductivity of an aluminum-based substrate). High conductivity types add a layer of thermal conductivity. This material is more expensive and the process is more complicated. (To 3.0 or above). Another important parameter is the withstand voltage. Generally, the ordinary version is between 500V-2500V (depending on the quality of the plate).