Step-by-Step Guide to Create Custom PCB Footprints

If you need a PCB footprint, but it does not exist in EasyEDA's component library, then you can create it yourself. And creating a device also requires a footprint library to complete. The usage method of the footprint library tool is the same as that of the PCB tool under PCB, but there are some unnecessary functions in the toolbar.

The footprint library is the various parameters of electronic components, chips, etc. (such as the size of components, length and width, in-line, patch, pad size, length and width of pins, spacing between pins, etc.) in a graphical way. Manifested so that it can be called when drawing the PCB. Creating a footprint library is almost identical to creating a symbol library. EasyEDA, a popular online PCB design tool, simplifies the process of creating custom footprints with its intuitive interface. In this guide, we’ll walk you through the step-by-step process of creating custom PCB footprints in EasyEDA. See more detail about electrical schematics design, from our latest blog.

PCB Pad Design and Development of Footprint?

PCB design and development involve creating the board’s layout, selecting the appropriate components, and designing the interconnections between them. Different components come with different pin configurations, numbers and package types. The uncovered metal area on an electrical circuit board where the factor lead has been soldered is known as the PCB pad. Aligning these pads together creates the component footmark PCB design model. The pad design involves two main factors:

1. Symbol design
2. Footprint design

We are using EasyEDA for the design because of its open source library and online environment.

Symbol Design:

Launch EasyEDA and go to the Schematic Editor. Open the Symbol Editor on the top menu, click on Libraries > Create Symbol.

• Use the drawing tools like Rectangle, Line, and Pin from the left toolbar to create the visual representation of your component.
• Add pins by selecting the "Pin" tool and placing them on your symbol. Make sure to number them according to your component’s datasheet.
• Label the pins with pin numbers and names to match the component’s specifications.
• Right-click the symbol and choose Properties. Here, you can enter the name, description, and other properties like reference designators (e.g., R for resistors, C for capacitors).
• Once your symbol is complete, click on Save and name your symbol appropriately. It will be saved to your personal library.

Footprint Design:

Step 1: Gather Component Data

Before you begin, collect the following data for the component:

• Datasheet: This provides the pin layout, dimensions, and other critical details.
• Mechanical Drawing: Look for the package type (e.g., SOIC, QFN, or TO-220).
• Pin Configuration: Verify the pin count and numbering.
• Recommended Footprint: Most datasheets include a recommended PCB layout.

Step 2: Open EasyEDA and Start a New Footprint

1. Log in to your EasyEDA account and navigate to the "Library" section.
2. Click “Create New Footprint” to open the footprint editor. This is where you’ll design the layout.

Step 3: Define the Basic Settings

• Name Your Footprint: Assign a descriptive name that corresponds to the component (e.g., “Custom-TO-220”).
• Unit Settings: Set the unit to millimeters (mm) or inches, depending on the datasheet.
• Grid Size: Adjust the grid size to match your design requirements. Smaller grids (e.g., 0.1 mm) are ideal for precise placement.

Step 4: Draw the Pad Layout

1. Add Pads: Use the “Pad” tool to place pins on the editor canvas.
2. Position Pads Accurately: Refer to the datasheet for exact coordinates and spacing. Adjust the pad size and shape (circular, rectangular, or oval) as specified.
3. Number the Pads: Double-click each pad to assign the corresponding pin number from the datasheet.

Step 5: Define the Silkscreen Outline

The silkscreen layer provides visual cues for assembly.

1. Use the “Line” tool on the silkscreen layer to draw the component outline.
2. Include alignment markers or notches to indicate pin 1 or orientation.
3. Add labels such as the part number or other identifying information.

Step 6: Add Courtyard and Assembly Layers

The courtyard defines the space the component occupies, ensuring no overlap with neighboring parts.

1. Switch to the Courtyard Layer and draw a rectangle around the pads and outline.
2. Ensure the courtyard is slightly larger than the component dimensions.

Step 7: Validate and Save the Footprint

1. Use the “Design Rule Check (DRC)” tool to verify that your footprint adheres to standard PCB design rules.
2. Save the footprint to your personal library with a unique name.

Step 8: Test the Footprint in a PCB Design

1. Open or create a schematic in EasyEDA.
2. Associate your custom footprint with the corresponding component.
3. Place the component in the PCB layout to ensure proper fit and alignment.

Tips for Accurate Custom Footprints

• Double-Check Measurements: Verify all dimensions against the datasheet before finalizing.

• Follow IPC Standards: Use IPC-7351 guidelines for footprint design when in doubt.

• Test with a Prototype: Print the footprint on paper to check against the actual component.

Conclusion

Creating custom PCB footprints in EasyEDA is a straightforward process once you understand the basics. With the right datasheet and careful attention to detail, you can design footprints that ensure accurate and reliable PCB designs. Mastering this skill opens the door to handling a wide range of components, from common to custom-made parts, enhancing your PCB design capabilities.

Start designing today and unlock the full potential of your EasyEDA projects!