# FR-1 Trace lengths

## The experiment
For the experiment, I used FR-1 that has a thickness of 35µm. On there I will mill 4 trace sizes (0.4 mm, 0,6 mm, 0,8 mm and 1 mm) and they all have the same length of 7.5 cm’s. The traces are seperated by 1 Cm.

![alt text](FR-1-Traces.jpg)

In this experiment I will measure the temperature of the traces with a multimeter and a thermal laser. I will also watch the board closely for any damage. Since it is FR-1 I expect it to shows signs of damage under heat

## Results

the power. So I grabbed an old robot with 4 stepper motors attached but I could not get them to draw more than 30 watts. So that is why the maximum in this test is 30 watts. I also had a hard time finding a way to measure the temperature of the traces because we only had a heat gun here and the laser was not the place it was actually measuring. So 0,4 mm is not measured properly.

| Trace Width Trace | Resistance | Maximum safe wattage | Burn out wattage |
| :---------------- | ---------- | -------------------- | ---------------- |
| 0,4mm             | 3,1Ω       | 15                   | 20               |
| 0,6mm 2           | 2Ω         | 22                   | 26               |
| 0,8mm             | 2Ω         | 27                   | ??               |
| 1mm               | 1,85Ω      | ??                   | ??               |
|                   |            |                      |                  |


 * The 0,4 mm trace was the first one I tested. I started with 15 watts. After that I increased the wattage to 20 watts and the trace instantly exploded and burned so I could not get temperature readings there. 

 * The 0,6 mm trace it held up well up to 27 watts where it started getting burn marks within a 5-10 seconds. The temperature rose to 45 degrees celsius. At 29 watts the pcb burned out at 68 degrees celsius.
 *  When testing the 0,8 mm trace I hit a roof with how much power I could consume with the robot. I could only get up to 30 watts and I did not manage to break the trace. The maximum I found before it started discoloring was 24 watts at 54 degrees celsius. This was measured after it was left on for 2 minutes.  
 * I could not get to the 1mm trace because the robot could not draw more than 30 watts. So thats why these are not filled in the table.

## Recommendations for next time
Make bigger pads to hookup the power easier to the pcb and maybe remove all the excess copper but that takes a super long time.

![alt text](image.jpg)
![alt text](image-1.jpg)

## Files
* [KiCad](TraceThicknesTest.zip)