KiCad Applications

In this section, we will explore the individual applications within the KiCad software suite. Each application has a distinct role in the PCB design process, and mastering these tools is key to developing high-quality, professional-grade printed circuit boards. In this documentation, we’ll take a guided tour through the Schematic Editor, PCB Editor, Symbol Editor, Footprint Editor, and several additional tools within KiCad. We’ll also highlight best practices and advanced tips for each tool.

1. Schematic Editor Overview

The Schematic Editor is the starting point for most PCB projects in KiCad. It allows you to create the logical representation of your circuit, which includes components and their connections. Though KiCad is flexible and allows users to create a PCB without first designing a schematic, it is highly recommended to always start with the schematic editor, as it captures all necessary data required by the PCB layout.

Key Features of the Schematic Editor:

  • Component Placement: Place components such as resistors, capacitors, and integrated circuits (ICs) using predefined symbols.
  • Connections: Connect components with wires or labels to indicate electrical connections.
  • Power Nets and Buses: Define power and ground connections (e.g., VCC, GND) and use buses to group signals for better organization.
  • Net Labels: Instead of drawing wires, you can use labels to connect pins by name, ensuring they are logically and electrically connected.

Example Workflow:

In the schematic editor, you’ll add symbols like resistors (R1, R2) and microcontroller units (U1, U2). Connections between components are made with wires or by assigning net labels (e.g., GND, VCC). This diagram forms the blueprint for your PCB layout.

2. PCB Editor Overview

The PCB Editor is where you physically design the PCB after completing the schematic. Once the schematic is finished, you can import the components and begin arranging them on the board, routing traces, and setting up the layers.

Key Features of the PCB Editor:

  • Component Placement: Import components from the schematic and place them on the board. Each component has an associated footprint that defines its physical size and pad configuration.
  • Trace Routing: Connect components by drawing traces (wires) that follow the signal paths between components.
  • Layers: Work with multiple layers, including front copper, back copper, silkscreen, and ground planes.
  • Design Rule Checks (DRC): Ensure that your board follows manufacturing guidelines, such as spacing between traces and pad sizes.

Example Workflow:

In the PCB Editor, once components are imported from the schematic, you place them on the board in the desired locations. Then, you route the signal paths using traces, ensuring all electrical connections are completed. KiCad provides visual indicators if there are any conflicts or errors, making it easier to adjust your design.

3. 3D Viewer

One of the standout features of KiCad is the 3D Viewer, which allows you to visualize your PCB in three dimensions. This feature is particularly useful for spotting mechanical issues, verifying component placement, and checking silkscreen alignment.

Key Features of the 3D Viewer:

  • Visual Inspection: Get a 3D representation of your board, including components, traces, and silkscreen.
  • Error Detection: Identify potential errors in component placement, such as misaligned headers or connectors.
  • Customization: You can adjust the view, rotate the board, and zoom in to inspect specific areas closely.

Best Practice:

Before submitting your board for manufacturing, always check it in the 3D Viewer to catch any mistakes that are hard to spot in 2D, like silkscreen overlap or component clearance issues.

4. Symbol Editor

The Symbol Editor allows you to modify existing symbols or create new ones from scratch. While KiCad comes with a large library of symbols, you may encounter cases where you need a custom symbol for a specific component.

Key Features of the Symbol Editor:

  • Editing Existing Symbols: Modify built-in symbols to suit your project’s needs and save them as new versions.
  • Creating New Symbols: Design symbols from scratch for components not available in the default libraries.
  • Customization: Symbols can be resized, pins repositioned, and additional attributes added to match the specifications of your component.

Example Workflow:

If your project includes a unique IC that doesn’t have a symbol in the standard library, you can create one by defining the pins, assigning labels, and adding custom attributes.

5. Footprint Editor

Similar to the Symbol Editor, the Footprint Editor allows you to modify or create footprints. Footprints represent the physical layout of components on the PCB, including the pads, holes, and outlines.

Key Features of the Footprint Editor:

  • Custom Footprints: Create footprints for components that don’t exist in the standard libraries.
  • Footprint Wizard: Use predefined templates to quickly generate footprints for common package types, such as QFN, BGA, or SOIC.
  • Layer Management: Define which layers the component pads will appear on and adjust pad sizes and shapes.

Best Practice:

Use the Footprint Wizard to speed up the creation of common footprints and ensure your custom footprints meet manufacturing standards.

6. Gerber Viewer

The Gerber Viewer is used for the final inspection of Gerber files before sending them to a manufacturer. Gerber files represent each layer of the PCB, including copper, silkscreen, and drill holes.

Key Features of the Gerber Viewer:

  • Layer Inspection: Visualize each layer of your PCB to ensure it meets design specifications.
  • Error Detection: Look for any potential issues, such as missing traces or incorrectly placed drill holes.
  • File Management: Load multiple layers simultaneously to get a full picture of your design.

Best Practice:

Always inspect your Gerber files using the Gerber Viewer before submitting them for manufacturing. This helps to catch any potential problems that may have been overlooked during the design process.

7. Image Converter

The Image Converter allows you to convert bitmap images into PCB graphics. This tool is especially useful for adding custom logos or graphics to your PCB design.

Key Features of the Image Converter:

  • Image to Footprint: Convert bitmap images into footprints that can be placed on your PCB.
  • Silkscreen and Copper Layer Graphics: Add decorative elements to your board, such as logos or text.

Example Workflow:

To add a custom logo to your PCB, convert a bitmap image using the Image Converter and place it on the silkscreen or copper layer using the Footprint Editor.

8. Calculator Tools

KiCad includes a set of Calculator Tools that help with common PCB design calculations, such as determining the appropriate trace width for current capacity.

Key Calculators:

  • Track Width Calculator: Calculate the necessary width for a PCB trace based on current, temperature rise, and trace length.
  • Impedance Calculator: Estimate the impedance of traces for high-speed designs.
  • Via Size Calculator: Determine the appropriate via size for signal and power routing.

Best Practice:

Use the Track Width Calculator when designing power traces to ensure that they can handle the expected current without overheating or causing voltage drops.

9. Drawing Sheet Editor

The Drawing Sheet Editor allows you to customize the size, layout, and content of the schematic sheets. You can add company logos, project titles, and other details to the title block or border.

Key Features of the Drawing Sheet Editor:

  • Custom Sheet Sizes: Define the size and orientation of the schematic sheet.
  • Title Block Customization: Add project-specific information like revision numbers, author details, and dates.

Best Practice:

Create a custom sheet template for your projects that includes all necessary information, such as company details and project descriptions. This ensures consistency across multiple designs.

10. Plugin and Content Manager

The Plugin and Content Manager allows you to extend the functionality of KiCad by installing external plugins. These plugins can add new features or improve existing ones, such as automated routing or design rule checks.

Key Plugins:

  • FreeRouting: Automatically route traces on your PCB, saving time in the layout process.
  • DFM (Design for Manufacturing): Checks your design for manufacturability issues, such as incorrect pad sizes or drill hole placements.
  • Interactive HTML BOM: Generate a clickable Bill of Materials (BOM) that helps with component placement and ordering.

Best Practice:

Explore third-party plugins and repositories to enhance your KiCad workflow. Popular plugins like FreeRouting and DFM tools can save time and improve the overall quality of your designs.

Conclusion

This section covered an overview of KiCad’s individual applications and tools, each playing a crucial role in the PCB design process. As you continue through the course, you'll gain deeper insight into each tool and learn how to apply them effectively in your projects. By mastering these tools, you'll be able to create professional, reliable PCB designs with KiCad.