Printed circuit boards, or PCBs, are the foundation of most electronic devices. They are made by layering thin sheets of copper onto a non-conductive substrate, and then etching away the excess copper to create the desired circuit pattern.
PCBs can be very simple, with just a few copper traces, or extremely complex, with several layers of interconnecting circuitry, effectively forming a 3D mesh. The manufacturing process must be carefully controlled to ensure that the finished PCB meets the desired specifications without missing or intermittent contact.
There are several methods that can be used to create the circuit pattern on a PCB. The choice of method will depend on the complexity of the desired pattern. The most common methods, used also in the 2 videos below, for creating circuit patterns on PCBs are photolithography and etching:
- Photolithography is a process of using light to create the desired circuit pattern on the PCB. A light-sensitive material called a photoresist is used to coat the PCB. The desired pattern is then transferred onto the photoresist using a mask. The exposed areas of the photoresist are then developed, which leaves behind a negative image of the desired pattern.
- Etching: this next step is to etch away the exposed copper to create the desired circuit pattern. There are many different etching chemicals that can be used, depending on the type of copper being used and the desired results.
Once the etching is complete, the remaining photoresist is removed, leaving behind the desired circuit pattern on the PCB, ready for the next steps, such as surface treatment, coating, piercing, and vias.
These steps are shown in much more detail and explanations in the two PCB manufacturing factories hereafter, from order intake to control and packaging, achieving the impressive KPIs of
- total delivery time from order intake to shipping: 2 to 4 days
- 5000+ orders per day!
and this for unit orders, not necessarily returning customers, for pros and non-pros -meaning potential errors in the demand-, and some design and quality checks along the process. Be inspired!
And then how its competitor does it, JLCPCB
For further electronic vocabulary, PCB types, and components footprints, refer to the PCB and electronic reference detailed Post.