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Week 8. Electronics Production

This week we completed both group and individual assignments.

Group Assignment

Electronic Components

This week, our instructor Onik Babajanyan introduced the main electronic components and explained their roles in electronic circuits. These included resistors, capacitors, LEDs, diodes, MOSFETs, voltage regulators, and transistors.

Inductor

An inductor is an electronic component that stores energy in the form of a magnetic field. It is usually made from a coil of wire and is commonly used in filters, power supplies, and various electronic circuits.

Diode

A diode is a semiconductor component that allows current to flow in only one direction. It is widely used for rectification and for protecting circuits from reverse polarity.

MOSFET

A MOSFET is a type of transistor that acts as an electronic switch or amplifier. It is voltage-controlled and allows switching large currents using a small control signal.

LDO (Low Dropout Regulator)

An LDO is a type of voltage regulator that provides a stable output voltage even when the input voltage is only slightly higher than the output voltage. It is commonly used to power microcontrollers and other sensitive electronics.

Voltage Regulator

A voltage regulator is a component or circuit that maintains a constant output voltage regardless of variations in input voltage or load conditions. It is essential for the reliable operation of electronic systems.

During the group assignment, I worked with my teammates Gevorg Malkhasyan, Mariam Daghbashyan, and Hrach Barseghyan.

Our main goal was to study and define the design rules used for PCB milling in our lab.

We:

  • studied the limits of trace widths and clearances,
  • tested different tools and parameters,
  • determined the acceptable ranges for reliable production.

Milling Process

To fabricate a test PCB sample, we followed these steps:

  • Configured VPanel to control the CNC machine,
  • Fixed the PCB board into an MDF base,
  • Set the zero positions for the X, Y, and Z axes,
  • Generated G-code and verified the toolpaths.

During the testing process, we used two different milling tools:

  • a 0.1 mm V-bit for fine traces,
  • a 0.4 mm flat endmill for more stable and precise results.

The goal of this experiment was to compare the effect of different tools on PCB milling quality and determine which one is more suitable for precise work.

Tool Comparison

The tests were performed using two different tools: a 0.1 mm V-bit and a 0.4 mm flat endmill.

Observations

The 0.4 mm flat endmill provided:

  • clean and sharp traces,
  • consistent width,
  • good separation in fine areas.

The 0.1 mm V-bit provided:

  • variable width (depending on depth),
  • rougher edges,
  • less precise results.

Conclusion

This experiment showed that the flat endmill is more reliable and precise for PCB milling, while the V-bit is highly dependent on Z-depth and produces less consistent results.

Learning Outcomes

During the experiments, we used the Mods software to generate G-code from design files, which allowed us to precisely control the milling process and adapt the toolpaths to our machine parameters.

Additionally, as part of the assignment, we sent a PCB design to an external board house to study the external manufacturing process and compare it with our in-house workflow.

This group work provided us with practical experience in PCB design and milling, and helped us better understand manufacturing constraints and their impact on the final result.

Details on the Group Assignments page.

Individual assignment

In my individual task, I decided to mill the board that I designed during Electronics Design week. The goal was to create a functional system combining sensors and output devices to interact with the environment.

After preparing the file for export, I navigated to File → Fabrication Outputs → Gerbers (.gbr). In the opened window, I changed the plot format from Gerber to SVG to match the required output format for further processing.

I then exported the PCB design in SVG format, as it is vector-based and ensures high precision. At this stage, I selected only the necessary layers — F.Cu and Edge.Cuts — since the board is single-sided and does not require the use of the *B.Cu layer. This helps avoid unnecessary data and reduces the risk of errors during the fabrication process.

Before that, I opened the exported SVG file in Inkscape to verify that the dimensions of the PCB had not changed during the export process.

Next, I proceeded to generate the G-code. I accessed MODS Project through the browser and, from the available options, selected Mill 2D PCB in the G-code section. This step allowed me to prepare the toolpaths and generate the final file required for the milling process.

At this stage, I applied the invert operation, since in the milling process the black areas are interpreted as material to be removed. This ensures that the copper traces are preserved while the surrounding material is milled away.

In the next step, I defined the milling parameters, including the tool diameter and cutting depth. These values were selected based on the required precision of the traces as well as the capabilities of the machine, ensuring accurate and reliable milling results.

After defining the milling parameters, I first activated the on/off switch (1) to enable the automatic workflow. This means that after pressing calculate, the result would be immediately passed through the modules and prepared for saving.

Then, I clicked the calculate button (2), and the program generated the toolpath and automatically forwarded it to the next modules.

I reviewed the generated toolpath in the preview (3), where the milling paths on the PCB were clearly visible. The red lines represent the tool movements between different areas.

In addition, I checked the 3D view, which allowed me to visualize how the material would be removed during the milling process. This step helped me better understand the depth and overall result of the machining.

Since the on/off option was already enabled, the toolpath was directly sent to the path to G-code module, where it was converted into machine-readable G-code for the CNC machine.

Finally, the file was saved as a .nc file, ready to be used for the milling process.