Important PCB Manufacturing Process
No matter you’re a PCB designer, engineering, hobbyist, student, etc., you’re clearly know that the process followed for manufacturing PCB boards is very important. As PCBs are the very basis of all electronic circuits, they come into different types--rigid, flexible, rigid flex, high density interconnect (HDI), etc. The difference among them is mainly determined by which material is used to fabricate. In fact, the main stages in the PCB manufacturing process remain the same, irrespective of the nature of the PCB.
However, before coming to the manufacturing stage, the designer has to decide a few points like select the type of PCB required by the application, decide if the board will have single, double, or multiple layers, decide the mechanical layout, the stack-up, and the routing of tracks on different layers, as well as produce relevant documents and files for the manufacturing process.
The above steps are important for the success of the final product, and its stability and reliability when used in the application. For example, if the application requires a component moves back and forth during operation, such as the head of a printer does, a flexible circuit must supply it. Most wearables are shrinking in size, so HDI technology is most suitable for the rigid-flex boards. At this stage, designer choose the material for the PCB design. The complexity of the electrical circuit that goes into the design decides the number of layers on the PCB. With the area available on gadgets shrinking as they tend towards miniaturization, the density of PCBs also increases proportionately. The only option for the designer is to have multiple layers on the PCB to contain the design within the specified mechanical boundary.
Depending on the nature of the application, the designer has to decide on the stack-up, or the design of consecutive layers. For example, if the application has high frequency circuits, the impedance and minimize crosstalk have to be defined. In this case, power and ground layers are alternately needed with races carrying signals in between. At the same time, the width, spacing, and routing of traces, placing of vias and test pads, etc. need to be determined. Once completing the design process, the designer produces an output in the form of standard documentation, which helps the manufacturer fabricate the specified design. This documentation can follow either the Gerber X2 format or the IPC-2581 format.