The hardest problem here is driving six channels at 5A each, 30A in total, from a touchscreen that only speaks 3.3V logic. Gate-to-source threshold requirements rule out direct switching at that level, and the maker handled it with a Microchip MIC4416 low-side driver that translates the logic up to the gate voltages the MOSFETs need. That decision sits at the heart of the whole design.
The board, named Slim Sculpt PRO V3.0, is a two-layer PCB with 2oz copper, laid out in KiCad 5 as a 12V low-side switching controller. Routing that much current on two layers without an external bus bar strikes me as a bold call, and it will be interesting to see how it performs. Power comes from a Murata OKI-78SR switching regulator that drops 12V down to 5V for the LCD, which draws 0.5A. A linear part would have overheated at that drop, so the switching route makes sense to me.
What stands out most is the thermal homework. The ROHM RQ3E080BN MOSFETs, rated 30V and 15A with 15.2 mOhm maximum RDS(on), work out to 0.38W per channel at 5A. With a junction-to-ambient thermal resistance of 62.5 C/W that gives a 23.75 C rise, putting the junction near 48.75 C at 25 C ambient. The maker worked this through in a Word document and studied the datasheet characteristic curves during part selection, which is exactly the diligence I want to see in a shared project.
One open point: the exact circuit function of the rendered board is not spelled out yet. With the series only two parts in, there is still plenty left to explain about how the channels come together.
Project by MicroType Engineering. Watch it on their YouTube channel: