PCB Fabrication Process
PCB fabrication is the process that transforms the design of a circuit board design to a physical structure according to the specifications included in the design package. It is an outsourced activity and not a design activity that is supposed to be performed by a CM, i.e., a Contract Manufacturer. Fabrication is not a design activity. However, manufacturers do it in adherence to the client’s requirements to the CM. The contract manufacturer is usually not aware of your design intent or the objective of your performance. Hence, they are not aware of the choices of materials, layout, locations, trace parameters, or other factors set during fabrication that may impact the PCB’s manufacturability or production yield rate after deployment.
Manufacturability:
The manufacturability of the board depends on the number of design choices available. That includes ensuring the adequate clearness between the surface elements, board edge, and the selected material should be a high coefficient of thermal expansion to withstand the PCBA on PCB, especially for no lead soldering. If you choose to finalize the designs, that must be forethought.
Yield rate:
The board can still be fabricated successfully, even with fabrication issues.
Reliability:
The board’s construction must achieve three classification levels for rigid PCBs to offer a specified level of performance reliability. If the manufacturers build the board to meet a lesser classification than the application requires will result in an inconsistent operation or premature failure of the board.
Hence, it is crucial to understand the process of PCB fabrication as the design choices will be affected throughout the PCB development and operation. The best way to defend against the issues arising from the PCB fabricating process is to utilize the design for manufacturing rules and guidelines according to the capabilities of your CM.
Basic requirements of a PCB Fabrication
PCB Fabrication is the process that helps in building the raw board, which serves as the foundation for the final circuit board assembly.
Circuit board details:
Before beginning a PCB layout, the design team contacts the contract manufacturer to develop the physical board’s parameters and configuration. This information is vital for the layout of the design, and it helps in designing and deciding the PCB fabrication vendor that will be best for the job.
Completed PCB Design:
The initial design should be complete to ensure the accuracy of the manufacturing of PCB. A simple component that the design team might not update can lack synchronization between the schematic and layout.
Full Manufacturing Design Data:
With the complete design ready to be built, they generate a full set of fabrication and assembly data to submit to the contract manufacturer. The PCB contract manager will be using these files to conduct their designs and then send them to the vendor for fabrication to quote for the build of bare boards.
What Must you Include in the Checklist?
After preparing all the items in the checklist, the contract manufacturer will order the bare circuit boards required for the assembly. The contract manager will typically have a list of the preferred fabricators that can be worked with and will accordingly choose the vendor whose capabilities match the technical requirements of the circuit board. Another factor that they consider is whether or not the circuit board is a prototype. If it is, the fabrication vendor should have the ability to run a production line separate from the normal process.
In short, manufacturers have to follow the following techniques throughout the PCB fabrication process:
- Image the desired layout.
- Remove the excess copper from the inner layers.
- To create a PCB layer, stack up through laminating.
- Drill holes for mounting through vias and hole pins.
- Playing via holes and pinholes.
- Add a protective coating or solder masking.
- Add a finish to copper areas.
Many use printed circuit boards (PCBs) in the simplest of electronic products, such as passive switch boxes.
Benefits of PCB Fabrication Process
PCB can be single-sided, double-sided, or Multilayered as well. Multilayer PCB allows a much higher density for components as the circuit traces on the inner layers will take up the surface between the elements. The popularity of the multilayer PCB with more than four is concurrent. However, multilayer PCB analyses and helps in the field modification of circuits.
Whether you need a few boards to be fast or multiple boards are on schedule. There are products available of all kinds that will fit your needs.
Rigid PCB:
These are available in a wide variety ranging from simple single-sided boards to highly multilayered boards with buried vias. In addition, manufacturers achieve a higher degree of integration through PVA technology. They also integrate additional functionality by using edge metallization.
Flex PCB:
These offer a wide range of physical and electrical interconnect solutions that manufacturers will not achieve with a rigid PCB.
Rigid-Flex PCB:
Manufacturers laminate rigid-flex PCB with rigid and flexible boards with interconnected wires and cables. They can customize both the sizes and layers accordingly, which helps in increasing durability and flexibility.
Building a PCB is the main goal in the end. However, there might be much pressure facing the electronic market, and hence your contract manager will help you build the prototype.
Venture Electronics will help you with the following:
- Component sourcing as well as procurement.
- Design engineering and the layout capabilities of the PCV.
- Bill of reviews with recommended alternatives.
- Design the manufacturer’s ability review as well as the corrections required.
Conclusion
The PCB assembly must start with the highest quality of board fabrication. Hence, a group of established PCB fabricators deals with the same locally and overseas to ensure that they complete the project with utmost quality.