PCB Board Design: A Step-by-Step Guide for Beginners

Printed Circuit Boards (PCBs) form the backbone of most modern electronic devices, providing a platform to connect electronic components. For beginners, PCB design can seem complex, but with the right approach, it becomes a manageable and rewarding task. This guide will walk you through the step-by-step process of designing a PCB, from planning to final checks.

Today, as an example we will go through a design process of a lithium-ion battery charging module. TP4056 is one of the most popular charging modules available, so it would be fantastic to create a version 2 of the famous TP4056 charging module. But to increase the current rating we replaced the circuit with a new IC named IP2312 keeping the PCB form factor similar to TP4056. Which has capabilities to drive up to 3A. To see the full fledged tutorial on the design see this post.

Design Steps for Printed Circuit Board:

Step 1: Understanding Your Circuit Requirements

Before diving into design software, it's important to have a clear understanding of the circuit you want to build. Begin by drafting a schematic on paper or using software like KiCad, Eagle or EasyEDA. Include all necessary components, such as resistors, capacitors, microcontrollers, and connectors. Make sure each component is properly connected to ensure functionality. Usually the circuit design starts from a pen paper with inspiration from real world problems. Here in our case the problem is the large charging time of TP4056.

Step 2: Choose a PCB Design Software

For beginners, PCB design software with user-friendly interfaces is essential. Popular choices include KiCad, Eagle, and EasyEDA. These programs allow you to create schematics, layout the components, and design the traces that connect them. You can also find libraries of standard components to simplify the process. In order to keep the process simple we are using EasyEDA because of its huge library and online database.

Step 3: Create the Schematic

Once you have chosen your software, start by creating the schematic diagram. A schematic is a blueprint of the electrical connections, showing how components are linked. The schematics for a PCB can be created by having a look at the IC datasheet and arranging all the components as per that.

Sometimes we need to change the component values, types depending upon use cases. There are a lot of other alternatives to a certain component. The example schematic of the IP2312 based charging module is attached above, the circuit is sectioned into different parts to increase the overall readability and to reduce R&D time.

Step 4: Define the PCB Layout

After completing your schematic, the next step is defining the physical layout of your PCB. Which includes the following steps:

• Set the dimensions of the board.
• Place components logically to minimize trace length and optimize performance.
• Ensure components with specific orientations, like LEDs or connectors, are properly aligned.
• Avoid overlapping components and ensure there's enough clearance for soldering.

Here in our design all the components are placed near to each other to minimize trace length. As we are using a very small form factor of TP4056 and packing IP2312 in that orientation of components plays an important role in routing.

Step 5: Route Traces

Now comes the process of connecting the components with traces. Traces are the copper paths that carry electrical signals between components. Use the following guidelines:

• Keep traces as short as possible to reduce resistance and interference.
• Route power and ground traces carefully, keeping them wider for better performance.
• Pay attention to design rules, such as trace spacing, to avoid short circuits.
• Use vias to connect traces on different layers if needed in multi-layer PCBs.
• Keep the current rating and power dissipation factor of a track in mind.

PCB trace current rating calculation can be done through any online available tool. Design rules should be fulfilled, autorouting can be implemented in order to reduce development time but it may not offer the same reliability.

Step 6: Add Power and Ground Planes

For most PCBs, especially those handling significant current, adding a power and ground plane is crucial. A power plane distributes power evenly across the board, while a ground plane reduces electrical noise. These planes are typically solid copper areas that cover entire layers of the PCB.

Because this is a two layer design, we added ground planes on both sides in order to reduce input voltage noises. This plane is pure copper poured onto the board and joins the GND plane tracks in our case.

Step 7: Place Silkscreen and Other Markings

Add silkscreen labels for component identifiers, pin numbers, logos, or regulatory markings. The silkscreen layer is a vital tool for assembly and troubleshooting, helping to identify components and their placement. Make sure it doesn’t interfere with pads or traces. For more see our full article on a comprehensive guide on PCB silkscreen.

Step 8: Verify with Design Rule Check (DRC)

Before finalizing your design, run a Design Rule Check (DRC) to catch any errors such as spacing issues or unconnected traces. Most PCB design software includes a DRC tool, which helps ensure the design meets the manufacturer’s specifications and is error-free.

Step 9: Generate Gerber Files

After your design is complete and verified, you need to export Gerber files. These files contain the necessary information for manufacturers to fabricate your PCB. Each layer of your PCB (e.g., copper layers, silkscreen, solder mask) will be represented in these files.

Advantages of Using EasyEDA:

EasyEDA is a versatile tool for electronic engineers, hobbyists, and students, enabling fast and efficient circuit design, testing, and validation. Its user-friendly interface and unique features have made it a popular choice.

• Integration with Other Tools: EasyEDA supports multiple file formats like Altium, Eagle, and KiCad, making design import/export seamless. It also integrates with cloud platforms like Dropbox and Google Drive for easy project sharing and backup.

• Low Cost: EasyEDA is cost-effective, offering free options for small projects and affordable premium plans for advanced features.

• 3D Visualization: With its 3D visualization feature, users can view PCB designs in real-time, helping with component placement and identifying potential design issues.

• Schematic Capture and PCB Design: Users can design both schematics and PCBs in the same platform, with tools for importing designs or creating new ones from scratch.

• Large Component Library: EasyEDA offers an extensive library of components, including resistors, capacitors, transistors, and ICs. Users can also create or import custom components.

Conclusion

Finally, once you have your Gerber files, you can submit them to a PCB manufacturer. Many manufacturers offer online quoting tools where you upload the files, choose board specifications (such as material and thickness), and place your order.

Designing a PCB may seem intimidating at first, but by following these steps, even beginners can create functional and well-designed circuit boards. Practice is key over time, you'll develop the skills to optimize layouts, minimize noise, and produce high-quality designs. Happy designing.