Al-CCL is an Aluminum-based copper clad laminates with good heat dissipation function. Generally, Single layered Al-CCL panel is composed of a three-layer structure, which is a circuit layer (copper foil), an insulating layer and a metal of aluminum base layer. For high-end use, it is also designed as a double-sided board, and the structure is circuit layer, insulating layer, aluminum base, insulating layer, and circuit layer. Very few applications are multi-layer boards, which can be formed by bonding ordinary multi-layer PCB with insulating layers and aluminum bases.
China has mature production for Al-CCL sheets; factories practiced in below many kinds ways operation:
1, Screen Printed insulating glue Aluminum sheets + copper foil laminates.
2, Aluminum sheets + prepreg + copper foil laminates.
3, Aluminum sheets + polymer film + copper foil laminates.
4, Aluminum sheets + commercial insulating glued copper foil laminates.
Here are two factors:
1, Thermal conductivity for insulating media.
In Al-CCL sheets, Thermal conductivity ratio is subject to above insulating glue, polymer film, prepreg or insulating glued copper. For high grade Al-CCL, is made by prepreg, printed glue Aluminum or polymer film; for normal and led lighting purpose, commercial glued copper foil is widely adopted.
From view of factory production.
Screen printed insulating glue aluminum way, it needs many times repeating glue printing can then go up to expected insulating thickness, this process may increase defective ratio. In china, much few factories arrange process in this way.
Prepreg lamination, it will give much epoxy glue onto press-plates, thus the designed production circulation, should consider of press plate auto-cleaning and reversing connection with non-stop production requirement.
Polymer film can achieve high grade thermal conductivity ratio, its finishing is mainly for high grade Al-CCL sheets.
In china, the most popular process is commercial insulating glued copper foil laminates, sky lifting system is adopted for raw loading stage. Sheets polymer film can also be applied aside of loading if the order is for high grades of Al-CCL sheets.
2, Aluminum plate heating dissipation.
This is dependent of Aluminum thickness, aluminum purity and circuit thermal heating dissipator conducting shape.