The basic structure of the two sheets is different in main features.
The main characteristics: The heat dissipation of aluminum and FR-4 is compared with the heat resistance of the substrate: the aluminum is aluminum basis, and the FR-4 is a transistor. Due to the different heat dissipation of the basis, the testing data for temperature rise is different.
Performance:
From the comparison of the Aluminum pcb and the FR-4 pcb, due to the high heat dissipation of the metal substrate, the wires are significantly improved, which illustrates the high heat dissipation characteristics of the Aluminum from another perspective. The heat dissipation of the Aluminum is related to the thickness of its insulating layer and thermal conductivity. The thinner the insulating layer, the higher the thermal conductivity(but the lower the voltage resistance).
Machinability:
Aluminum has higher mechanical strength and toughness, which is better than FR-4.So large-area printed boards can be made on Aluminum substrates, on which large components can be mounted.
Electromagnetic shielding:
In order to ensure the performance of the circuit, certain components in electronic products need to be protected from radiation and interference of electromagnetic waves. The Aluminum can be used to shield electromagnetic waves.
Thermal expansion coefficient:
Due to the thermal expansion of FR-4, and particularly the thickness of the board, the quality of the metallized holes and wires will be affected. The main reason is that the thermal expansion coefficient of copper in the raw material is 17106cm/cm-C, and the FR-4 sheet is 110106cm/cm-C, the difference is large, and it is easy to cause heated substrate expansion and change copper wire as well as Detrimental effect of metal hole rupture on product reliability. The thermal expansion coefficient of the Aluminum is 50×106cm/cm-C, which is smaller than that of the ordinary FR-4 board and close to the thermal expansion coefficient of the copper foil. This helps to ensure the quality and reliability of the printed circuit board.
The application circuit is different, the application field is different, the FR-4 board is suitable for general circuit and general electronic products.
