5. Electronics production¶

Group Assignment¶

This week, we had to document these parts:

Characterize the design rules for your in-house PCB production process: document feeds, speeds, plunge rate, depth of cut (traces and outline) and tooling.

The workflow for sending a PCB to a board house

Here is the link to our group assignment page.

Individual Assignment¶

This week I worked on making and testing my desgin circuit board with seeed studio XIAO-RP2040.

1. Milling my design circuit board¶

a. Preparing¶

I used ProtoMat S103 milling machine from LPKF Laser & Electronics.

machine name

First, I experted my pcb file into gerbers (.gbr) which will have 1 F_Cu file and 1 Egde_Cuts file, in order to milling my board and cut my board from a big FR4 plate. After I copy those files from my laptop to the computer connected with the machine, I started with setup the machine.

b. Setup and processing¶

1.Start process planning wizard

I choosed: Process PCBs -> Single-sided top -> FR4/FR5 First step Type of the process Layers of the board Kind of subtrate

2.Import data from a non-native format

At this step at import two gerber files from computer to the applicant. Then, two files will be shown with 2D view Step 2 2D view of the Edge Cuts file 2D view of the Front Cu file Combination of two files

3.Create an area where all unnecessary copper is removed

4.Create fiducials in the CAM view

These two steps were skipped in my design because i do not need these but I still consider later for my next milling. Step 3 Step 4

5.Generate isolation and contour routing toolpath

At this step, I will isolate paths and pins from the GND, and choose how to cut the Edge_Cuts path. Step 5

There are two recommended choices for isolation: Basic and Pads Double Basic Isolation Pads Double Isolation

Next, Contour routing. There are six different ways to choose, but i chose Vertical Gaps. Vertical Gaps Contour Routing

After finish this fifth step, the software showed how my circuit board was milled, cut and required tools for the process. Milling and Cutting

6.Open the dialog to edit the contents of the tool magazine

In the step, the software show about the required tools for my design is still able to mill and cut or need a new replacement. Step 6 The remaining durability of all tools

7.Start the Board Production Wizard

There are many stages for this step:

Mount material Small stages in this step Material settings and Location Material settings and choosing Location

Processing with XYZ-positioning Buttons to move milling hand I move it to find a good location for my design

I had chosen a good corner for my design First corner Then I adjust the location to get another corner Next location Second corner

Lastly, I moved my board to a position that I wanted it to mill and cut The position for my circuit board

After this, the machine started milling and then cutting my circuit board. While this process occurs, I paid attention for the tools if there is a problem with changing tools in the process. Then I should stop the machine.

Last step: Vacuum the dust and remove the circuit board from the machine.

Result: Unluckily, there is a problem with my first design that the clearance between paths and GND was not clear enough so it made some short circuits at some points. First result

Then I changed the clearance from 0.2 mm to 0.25 mm and it worked well this time. After that, I used scouring pad to clean copper oxide layer on the top for electrical conductance.

2. Soldering components into my circuit board¶

Soldering microcontroler XIAO RP2040 with pins¶

This is the first step for me to be able to connect the microcontroller to my circuit board. The trick for this part that I used a trick tool that allign all pins to able to connect with different boards with a same microcontroller. We also can use prototype board for more common. XIAO RP2040 with pins Soldered microcontroller

There are many techniques that can help you to solder components to the circuit board. I used pre-soldering on the connection, then I reheated that to connect them. Soldering Components

With LED, I need to measure before soldering because it is a diode. Also be careful with Ohrom twitch not to make short circuit. Here is the final result for my design.

3. Testing my circuit board¶

Using multimeter¶

I used multimeter to check all my connect is good or any of them is short circuit

Using Arduino IDE¶

I uploaded some example codes to test the microcontroller. With Arduino IDE, I need to setup the software for the board recognization. You can find the details how to connect the XIAO RP2040 to your laptop or computer. Links

Files¶

Gerber F_Cu file Gerber Edge_Cuts file

Conclusion¶

This individual assignment demonstrated on how I milling my design circuit board, soldering components, and testing it with different ways.