It’s not difficult to warm up your electronic project. The designed track is too small. If the battery input is accidentally shorted together, it may reverse to the voltage of MCU. We have cooked one or two dishes over the years. However, how to make a deliberately hot PCB? This is exactly what [Carl bugeja] did when revising the PCB hot plate for the second time, which is designed to reflow other PCBs.
[Carl] tried to make a hot plate for the first time, but it was neither hot nor cold. This plate is a bending mark on the top of the aluminum substrate, and it has indeed heated as expected. However, the thin substrate causes a large amount of warpage of the hot plate during heating, reducing the contact with the welded plate. Most importantly, the resistance is much greater than expected, resulting in lower heat output.
The new version of the circuit board is located on a thicker substrate and has thicker traces, reducing the resistance from 36 ohms previously designed to only 1 ohm. The thicker substrate, with newer design and fewer slots, makes the surface more firm and will not bend when heated.
We especially like the wiring scheme Paul designed for his new hot plate. Welding to a resistance heater can be a huge annoyance because the circuit board will act as a radiator. Although alligator clips work in the test, they always have the possibility of slipping and short circuiting each other. [Paul] decided to make a custom flexible PCB, connect it to the hot plate with nylon screws, and install it directly on his power connection point.
Unfortunately, this new amendment of the board of directors also has some problems. The biggest problem is that the communication with the circuit board manufacturer is wrong, and the solder mask used begins to degrade after several hours at the operating temperature. But for light work and intermittent use, it is the perfect tool.
You can read more about [Paul] the first PCB hot board in our previous report.