Preliminary Work of Circuit Board Design
Schematic Design:
- Use schematic design tools to create schematic diagrams and generate network tables.
- If network tables already exist for simple circuits, schematic design can be skipped.
Manual Network Table Adjustments:
- Manually adjust the network table by:
- Defining pads not on the schematic, such as fixed pins, and connecting them correctly.
- Matching device pin names with the PCB package library.
- Assigning physically unconnected pins to ground or protection ground.
Drawing the Package Library of Non-Standard Devices
- Create a separate design file for custom components within the PCB library.
Setting up PCB Design Environment and Drawing the Frame
PCB Design Environment Setup:
- Configure parameters like grid size, cursor type, layout, and wiring settings.
- Default parameter values can be used, based on personal preferences.
Circuit Board Planning:
- Plan the board border, including size and placement of mounting holes.
- Before drawing the border, set the current layer to Keep Out to prevent wiring.
Opening Required PCB Library Files and Loading Netlist
- Access necessary PCB library files.
- Load the netlist file and adjust part packages if necessary.
- The netlist is essential for automatic routing and serves as the link between schematic design and PCB layout.
Arranging Part Package Positions (Part Layout)
- Use Protel99 for automatic or manual layout arrangements.
- Consider mechanical structure, heat dissipation, and electromagnetic interference in part layout.
- Utilize interactive layout options for efficient positioning.
Making Adjustments and Locking Devices
- Make necessary adjustments to layout considering mechanical, heat, and electromagnetic aspects.
- Include fixing screw holes, test pads, and adjust via hole sizes.
- Secure all devices after adjustments.
- Use the VIEW3D function to review the actual impact and save the design.