Printed circuit boards (PCB) are structures connecting electronic components via copper conductors, providing both electrical pathways and mechanical support. They consist of alternating conductive copper and insulating layers, with features such as traces and pads.
The first process in PCB fabrication involves creating the mechanical structure, which consists of a substrate, copper layers, and prepreg. The substrate, typically made of insulating materials like fiberglass or epoxy resin, forms the foundation of the PCB. It provides mechanical strength and electrical isolation between the conductive layers. The copper layers are thin sheets of copper foil laminated onto the substrate. These layers are patterned to form conductive traces, pads, and planes. The prepreg is a thin layer of insulating material placed between the copper layers to prevent electrical shorts and provide mechanical support. Other additional features in creating the mechanical structure are vias, solder mask, and silkscreen. Vias are holes drilled through the PCB layers to connect different copper layers, allowing for vertical electrical connections. Solder mask is a protective coating applied to the PCB to prevent solders from adhering to unwanted areas, ensuring reliable connections.
The silkscreen is a layer of ink printed on the solder mask to provide component identification and assembly guidance, An electrical diagram is used to create electrical pathways for the circuit board features, including copper traces, pads, and conductors.
