Week 6

PCB Milling and Fabrication

Introduction

This week, we explored the process of PCB milling and fabrication using the Bantam Tools Desktop PCB Milling Machine. My goal was to design and create a functional PCB for a simple electronic circuit, specifically a distance sensor using the VL53L1X Time-of-Flight sensor. The project involved several steps, including designing the schematic and PCB layout in Autodesk Eagle, milling the PCB, soldering components, and testing the final product.

Recitation

  • Using the OTHERMILL milling machine, you can switch out the tool bits for different tasks:
    • Small tool bit: 1/64 inch (for fine details)
    • Large tool bit: 1/32 inch (for larger cuts)
  • Cut the outline after completing all the small machining for better stability.
  • Tightening the tool bit when it is not fully in the shaft is less effective; tools are stored in the red box.
  • The machine verifies the tool position by touching the bed first (default moves to the top right, so boards are left-justified on the bottom edge).
  • Copper boards are 1.6mm thick, the standard thickness of copper stock (1 oz per square foot).
  • Safe jobs: You don't need to stay near the bed during operation.
  • Engraving bits have variable cut widths based on cut depth.
  • No overlapping tape on the back side of the board.
  • Minimum trace width the machine can cut: 0.009mm.
How to Make a Double-Sided Board
  • Use a rivet (tiny red piece with a circle on the end) to connect the two copper plates by smashing it into a hole.
  • For double-sided boards, use the fixture and locate feature:
    • The fixture is a U-shaped bracket you screw in to locate the board.

Software

  • Using Bantam software for PCB milling.
  • Three types of milling: holes, outline, and traces (set the tool for each type).
  • 1/32 inch tool for holes and outline.
  • 1/64 inch tool for traces.
UI Notes
  • Red areas on the design indicate parts the selected tool cannot cut.
  • White lines in the traces visualize the path of the selected tool.

Group Assignment Notes

  • Input to Bantam software: Gerber file or .brd (Fusion 360).
  • Input settings: Plated Through Holes, Front & Bottom Copper, Etched Cuts.
  • Sending a board to a board house: JLCPCB.

Individual Assignment

I designed a PCB for a distance + light sensor using the VL53L1X Time-of-Flight sensor. This is the first step of one of my final project ideas, making a

hydration detector

The design process involved creating a schematic and PCB layout in Autodesk Fusion, ensuring proper connections and component placements.

After milling the PCB using the Bantam Tools machine, I soldered the components onto the board, including the VL53L1X sensor, resistors, capacitors, and headers for connectivity.

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