> Regarding their PCB design (visible on the bottom of the page, with additional details here [1], could someone explain why the optic part is separated from th

> Regarding their PCB design (visible on the bottom of the page, with additional details here [1], could someone explain why the optic part is separated from the rest of the board by a long, wavy connection? I think the pcb has to be slightly bent to accommodate the angled position of the track ball. Making it like that helps alleviate stresses on the pcb.