Circuit layer
The circuit layer (generally using electrolytic copper foil) is etched to form a printed circuit, which is used to assemble and connect the devices. Compared with the traditional FR-4, with the same thickness and the same line width, the aluminum substrate can carry higher current.
Insulation
The insulating layer is the core technology of the aluminum substrate, which mainly plays the role of bonding, insulation and heat conduction. The aluminum substrate insulation layer is the largest thermal barrier in the power module structure. The better the thermal conductivity of the insulating layer, the more beneficial it is to the diffusion of heat generated during the operation of the device, and the more beneficial it is to reduce the operating temperature of the device, so as to increase the power load of the module, reduce the volume, extend the life, increase the power output .
A typical motor controller module uses a large number of heat sinks, thermal interface materials and other accessories. The module is bulky, complex in structure and high in assembly cost; and because of the use of aluminum substrate with high thermal conductivity, it is highly automated For surface-mount products, the entire product has been reduced from 130 to 18 parts, the power load has increased by 30%, and the module size has been greatly reduced. Such high-power-density modules can only be qualified with aluminum substrates with high thermal conductivity.
Metal base
What kind of metal is used for the insulated metal substrate depends on the comprehensive consideration of the thermal expansion coefficient, thermal conductivity, strength, hardness, weight, surface condition and cost of the metal substrate.
In general, considering the cost and technical performance, aluminum plate is an ideal choice. The available aluminum plates are 6061, 5052, 1060, etc. If there are requirements for higher thermal conductivity, mechanical properties, electrical properties and other special properties, copper plates, stainless steel plates, iron plates and silicon steel plates can also be used.
