PCB Board Fabrication
The circuit board serves as the foundation for an electrical device, so it’s important that it’s built properly. To ensure quality and functionality, the PCB fabrication process follows a set of standards and procedures. These processes begin with the initial design of the printed circuit board. PCB designers use a variety of PCB design software to create the layout and indicate where the components will go, route traces, and add capacitors and more. Once the PCB layout is complete, the designer exports it into a file format that their contract manufacturer (CM) supports. Ideally, both the OEM and CM use the same version of pcb board fabrication design software to avoid any discrepancies in file formats.
After the CAD/CAM design is complete, it moves to the fabrication stage. The bare copper layer is laid on the base material, which can be fiberglass-reinforced epoxy resin (FR4) or another material such as phenolic glass or polyimide. The conductive copper is then etched away, leaving behind the characteristic thin lines that carry current from one component to the next. The copper can be etched with various chemical solutions, but the most common is ferric chloride. To prevent damage to the underlying layer, the etching solution is kept at the right strength and is mixed with the copper at just the right time.
Once the conductive copper is etched, technicians apply a photosensitive coating to it. This is known as a solder mask, and it helps protect the exposed copper from damage during the soldering step of the fabrication process. Once the solder mask is applied, an automated optical inspection system (AOI) checks each inner layer pair of the circuit board for defects.
What is PCB Board Fabrication?
The plated-through holes (PTH) are the connecting points for the individual layers of the circuit board. The hole walls are plated with copper, and they are also used for soldering components to the boards. These connections are vital for ensuring that the traces in the patterned copper layer match up correctly with the components they connect to.
A legend, or silkscreen, is often added to the PCB to identify components and provide useful information for assembling, testing, and servicing the product. This is typically done with an etching process, but it can also be achieved through other means such as printing epoxy ink or using an AOI.
PCB (Printed Circuit Board) fabrication is a crucial process in the electronics industry, where circuit boards are created to mechanically support and electrically connect electronic components. These boards serve as the foundation for virtually all electronic devices, ranging from smartphones and computers to medical devices and industrial equipment. PCB fabrication involves a series of steps that transform a raw design into a physical board capable of supporting complex circuitry.
Once all the traces are connected, the remaining areas of the circuit board are covered with an epoxy solder mask. The bare copper is then cleaned to remove any contaminants, and the panels are placed in an oven to cure the mask. Finally, the panels are inspected again for any defects. The finished circuit board is then ready for assembly.
