Fabricating Aluminum PCBs:

Fabricating methods for Aluminum PCBs are like those manufacturers follow for regular PCBs. The design process is the same and uses the same CAD tools. The only exception is the designer must use only SMCs and place them only on one side. Although single-sided Aluminum PCBs have no vias, some manufacturers make double- and multi-layer Aluminum PCBs, with the design and manufacturing process sharing many similarities with that for FR-4 PCBs. However, some aspects of the manufacturing process call for rigorous and effective control and management.

Etching: Designers typically use Aluminum PCBs for power devices with heavy copper for the foil. For copper foil with thickness of 3 ounces or more, etching requires appropriate compensation for achieving the necessary trace width, which the designer must design appropriately. Additionally, it is necessary for the operator to control etching factors and agent parameters rigorously.

Printing Solder Mask: With thick copper foil on Aluminum PCBs, the top surface is not entirely flat, and there is a large step between trace edges and the base. This makes it difficult to print the solder mask. Some manufacturers get around this problem by printing the solder mask two times, susing an epoxy of high quality. Others use resin filling before printing the solder mask.

Mechanical Manufacturing: Aluminum PCBs often require to undergo mechanical manufacturing processes before they can be useful. This may include drilling, milling, V-scoring, and more. To preserve the high quality of the board, most manufacturers resort to electric milling with professional cutters for low-volume production, and die molding patterns with necessary controls for high-volume production. Drilling requires proper adjustments and controls on heavy copper Aluminum PCBs to prevent generation of burrs.