PC board design contains specification pertaining to the circuit, such as:
placement of components
electrical connections
routing
vias
Bulk manufacturing of PC boards involves computer-aided designs for ease of use and accuracy.
Steps Involved in PC Board Design
The PCB designing process involves:
Schematic capture: It is the process of creating an electronic diagram of the designed electronic circuit. Steps include:
Firstly, a rough circuit diagram is prepared on the paper and populated with circuit details.
A computer-generated copy of the electronic circuit diagram is developed using a schematic editor.
Availability of CAD software has added to the precision and visual representation of the circuit diagrams.
Size: Circuit board dimensions are decided based on:
the number of components to be mounted
design complexity
size of the equipment where the PCB is meant to be placed such as in the case of fans, where flexible PCBs are used to cover lesser space.
Deciding layers: Multiplicity of layers depends on the complexity of the circuit and the number of components. Factors to consider are:
Four to 12 layers are compatible for an average size circuit.
The ground and the power planes are also determined at this stage.
Ground planes act as a base non-conductive plate and power planes facilitate the flow of charge..
Quantifying impedance: The level of impedance is measured in term of:
thickness of the dielectric (insulated coating on copper base)
copper routes and their width.
Placement: While deciding on the placement of components, thermal behavior and geometry are considered. Vials are also marked.
Routing signals: The flow of the signals through copper traces is highlighted in the design. To ensure high conductivity, higher frequency signals are routed through internal layers of the circuit.
Gerber file creation: PCB manufacturing machines use a special file format called as Gerber File. This format supports:
detailing of minute components such as traces, soldering and vias.
These files are generated through specialized software.
The software facilitates computer-generated manufacturing.
Steps, their process in particular, varies with particular circuit requirements and complexities.
