Skip to content

3. Activity of Day 3

PCB Milling Techniques & Fabrication Process

Overview

Day 3 focused on PCB design for fabrication, specifically the creation of a single-sided microcontroller PCB using KiCad. The main objective was to understand the complete workflow from schematic design to PCB layout and preparation for milling and soldering.

Kicad Software

Kicad is a free and open-source PCB design software that supports the entire PCB development cycle, from schematic capture to generating fabrication-ready files.

KiCad Workflow

Each step builds on the previous one to ensure a robust and functional final product:

1. Schematic Creation - Define electrical connections.
2. Footprint Assignment - Link logical symbols to physical layouts.
3. PCB Layout - Arrange components and route traces.
4. Design Rule Check - Validate against manufacturing constraints.
5. Fabrication Files - Generate outputs for manufacturing.

Activity - Single-Sided Microcontroller PCB Design (KiCad)

Objective

Designing a single-sided PCB using KiCad that: - Uses an ATtiny45 microcontroller - Controls an LED using a push button - Can be programmed via a 6-pin ISP header - Is suitable for PCB milling and hand soldering

Block Diagram (Conceptual)

Components Specification

Design Workflow (KiCad)

The schematic was created in KiCad by placing all components and connecting them correctly according to the circuit design specification.

Each component in the schematic was assigned a suitable physical footprint to match the actual components used during fabrication.

  • Converted the schematic to PCB layout
  • Arranged components for a single-sided board

  • Routed tracks manually to avoid overlaps
  • Ensured the design was suitable for PCB milling
  • Verified there were no errors
    • No unconnected nets
    • No trace overlap

The final routing was reviewed to confirm all connections were correct and ready for fabrication.

Reflection

  • Challenges: Routing the PCB was challenging because once a trace occupies a path, another trace cannot cross it. This became especially difficult in areas with many connections, and had to change position of routes or change route width.

  • What I learned:

    • Component placement is critical in single-sided PCB design
    • Good planning reduces routing complexity
    • Designing for fabrication requires thinking ahead, not just connecting nets

Download Reference

Download Microcontroller PCB Design (KiCad zipped Folder)