Copper clad plate — also known as substrate.The reinforcing material is soaked in resin, and one or both sides are covered with copper foil.
It is the basic material of PCB, often called base material.When it is used in multilayer production, it is also called CORE.
A. According to the mechanical rigidity of copper-clad plate, it is divided into rigid copper-clad plate and flexible copper-clad plate;
B. According to the insulation materials and structures of copper-clad panels, it can be divided into organic resin copper-clad panels, metal core PCB and ceramic-based copper-clad panels;
C. According to the thickness of copper-clad plate, it is divided into thick plate (the thickness range is 0.8 ~ 3.2mm (including Cu)) and thin plate (the thickness range is less than 0.78mm (excluding Cu));
D. According to the reinforcing materials of copper clad plates, they are divided into glass cloth copper clad plates, paper copper clad plates and composite copper clad plates (cme-1 and cme-2).
E. Classified into flame retardant board and non-flame retardant board according to flame retardant grade.
F. According to some properties of copper clad plate, it can be divided into high Tg plate (Tg≥170℃), high dielectric property plate, high CTI plate (CTI≥600V), environment-friendly copper clad plate (halogen-free, antimony-free), and ultraviolet shaded copper clad plate.
Copper clad plate is the basic material of electronic industry, mainly used for processing and manufacturing printed circuit board (PCB), widely used in television, radio, computer, computer, mobile communication and other electronic products.
The surface of the power device is mounted on the circuit layer, and the heat generated during the operation of the device is rapidly transmitted to the metal base layer through the insulation layer, and then the metal base layer transfers the heat out, so as to realize the heat dissipation of the device.
Compared with the traditional fr-4, the aluminum substrate can reduce the thermal resistance to the minimum, so that the aluminum substrate has excellent thermal conductivity.Compared with the thick film ceramic circuit, its mechanical properties are excellent.
In addition, aluminum substrate has the following unique advantages:
Meet RoHs requirements;
More suitable for SMT process;
In the circuit design scheme, heat diffusion is treated effectively to reduce the module operating temperature, prolong the service life, and improve the power density and reliability.
Reduce the assembly of radiators and other hardware (including thermal interface materials), reduce the volume of products, and reduce the cost of hardware and assembly;Optimize power circuit and control circuit;
Replace fragile ceramic substrate for better mechanical endurance.
The circuit layer (usually electrolytic copper foil) is etched to form a printed circuit, which is used to realize the assembly and connection of devices.Compared with the traditional fr-4, the aluminum substrate can carry higher current with the same thickness and line width.
Insulation layer is the core technology of aluminum substrate, which mainly plays the functions of bonding, insulation and heat conduction.Aluminum substrate insulation layer is the largest thermal conductivity barrier in power module structure.The better the heat conduction performance of the insulation layer is, the more conducive it is to the diffusion of heat generated during the operation of the device, and the more conducive it is to reducing the operating temperature of the device, so as to increase the power load of the module, reduce the volume, prolong the life and increase the power output.
The type of metal used for insulating metal substrate depends on the thermal expansion coefficient, thermal conductivity, strength, hardness, weight, surface condition and cost of the substrate.
In general, from the cost and technical performance and other conditions to consider, aluminum plate is the ideal choice.The available aluminum plates are 6061,5052,1060, etc.Copper plate, stainless steel plate, iron plate and silicon steel plate can also be used if higher thermal conductivity, mechanical properties, electrical properties and other special properties are required.
Heat dissipation of aluminum PCB is higher than that of copper composite plate, heat dissipation of aluminum substrate and its insulation layer density and thermal conductivity, the thinner the insulation layer, the higher the thermal conductivity coefficient.
Compared with copper clad plate, aluminum PCB is better than copper clad plate.Aluminum PCB has high mechanical strength and tolerance, so it can be printed on aluminum PCB.
Aluminum PCB can be used as shielding plate to shield electromagnetic wave effect, but better than copper clad plate.
Because of the general thermal expansion of copper cladding, it is easy to affect the quality of metal holes and wires.The thermal expansion coefficient of aluminum PCB is lower than that of copper composite plate, which helps to ensure the quality and reliability of printed circuit board.