PCB design and manufacturing is a long, multi-step process requiring engineers with expertise in various fields. This is why many companies outsource it—it’s easier than setting up an internal team, plus this means that they don’t need to invest in related technology. In this article, we go through the whole PCB design and manufacturing process in more detail. Read on if you want to learn more!
What Is PCB Design and Manufacturing?
Let’s start with some general information.
PCB Design
PCB design is the process of designing the layout of a printed circuit board. It is especially important for businesses that need custom PCBs since these need to be created from scratch. However, it is also possible to skip this step and opt for ready designs.
Learn more: What Is PCB Design and What Is It Used for?
PCB Manufacturing
PCB manufacturing refers to the process of turning the design into a complete product. It involves all the steps, from creating a blank board to attaching the components, securing them, and testing the final PCB. While printed circuit board design mostly requires expertise, manufacturing is even more difficult since you need the equipment to etch, laminate, drill, and solder your PCBs—especially if you want to mass-produce them.
The PCB Design and Manufacturing Process Explained
PCB design and manufacturing are usually a part of the same process—first, you create a project, then you build a prototype, and finally, you build your line of printed circuit boards. The process can get quite complicated (especially with the more complex PCBs), so let’s look into all of the steps separately.
Design and Output
The process begins with designing the PCB layout using specialized software such as Eagle, Altium, or KiCAD. The design files include all the essential details: layer stack-up, copper traces, vias, and pads. These files are then prepared for production, ensuring the design meets manufacturing requirements.
What’s important is that you can create the design from scratch but also customize the existing designs—this is helpful if you just need small modifications.
Inner Layer Imaging
The design is transferred onto the inner copper layers of the PCB. This involves printing the layout using a light-sensitive photoresist material that hardens when exposed to UV light. The unhardened areas (unprotected by the design) are then washed away, leaving the intended circuit pattern on the copper layer.
Etching
PCB etching refers to removing unwanted copper using chemical processes. Only the copper protected by the photoresist remains, forming the required conductive traces. This step is critical for achieving clean and precise circuitry.
Photoresist Stripping
After etching, the hardened photoresist is stripped away to reveal the final copper pattern on the inner layers.
Inspection and Post-Etch Punch
The next PCB manufacturing step involves a thorough inspection with the aim of ensuring there are no defects like short circuits, open circuits, or etching errors. Post-etch punching aligns the layers accurately for lamination in later steps.
Brown Oxide Coating
After the inspection, a chemical treatment is applied to the inner layers to promote better adhesion between the layers during the lamination process. The brown oxide coating ensures the bonding is strong and reliable.
Lamination
If you manufacture a multi-layer printed circuit board, lamination is the step in which the individual layers (including inner copper layers and dielectric materials) are aligned and bonded together under high temperature and pressure.
Drilling
Holes are drilled through the laminated PCB stack to create vias and mounting holes. Vias are used for electrical connections between layers. High-precision drilling machines are used to ensure accuracy, as even slight misalignment can compromise the circuit.
Electroless Copper Deposition
The drilled holes are plated with a thin layer of copper through a chemical deposition process. This ensures that the holes can conduct electricity and form connections between layers.
Outer Layer Imaging
Like the inner layers, the outer layer circuitry design is transferred onto the PCB using photoresist and UV light. This step defines the conductive traces and pads on the outermost layers of the PCB.
Copper Plating
Once the outer layer image is applied, the PCB undergoes electroplating. Copper is deposited onto the exposed conductive areas and through the holes to ensure electrical connections’ efficiency throughout the layers.
Photoresist Stripping
After plating, the remaining photoresist on the outer layers is stripped away, exposing the final copper circuitry.
Final Etching
The unwanted copper on the outer layers is etched away, leaving only the desired conductive traces and pads.
Tin Stripping
The tin stripping PCB manufacturing step involves the removal of the protective tin applied in the earlier steps. The goal is to leave clean copper traces ready for the rest of the process.
Solder Mask Application
A solder mask (usually green) is applied to the board to protect the copper traces and prevent solder bridges during component soldering. Openings are left for pads where components will be mounted.
Surface Finish
After the solder mask is ready, you need to apply a surface finish to ensure a reliable and solderable surface. Common finishes include HASL (Hot Air Solder Leveling), ENIG (Electroless Nickel Immersion Gold), or OSP (Organic Solderability Preservative).
Silkscreen
Now it’s time for text and markings (component labels, logos, and instructions), which are printed onto the board using silkscreen. These markings help in the later steps (with component mounting) and make maintenance easier.
Electrical Testing
With all the above ready, the PCB undergoes electrical testing to verify that all circuits function as intended.
Profiling and V-Scoring
The final PCBs are cut or routed from the production panel. V-scoring or milling techniques are used to separate individual boards while leaving clean edges.
Conclusions
As you can see, the PCB design and manufacturing process is quite lengthy and complex. This is why it’s best to work with experts in the field who have the right knowledge and technology. Where to find them? At Conclusive! Contact us today, and let us help you with your PCB!
You may also read: What Are the Advantages of Custom PCB Manufacturing?