TECHNOLOGY THURSDAY: Finished Slot Size Tolerances

In the last TechThursday  we explained why there are always certain manufacturing tolerances in the holes of a PCB and why these tolerances have to be taken into account in the PCB design. A variant of the through-hole, which can also have a metallisation, is the slot. It is needed, for example, to attach components to the PCB. The slot can be thought of as two semicircles that are pulled apart in the middle. To produce this shape, the PCB manufacturer either drills several holes very close together until the slot hole has the required length, or mills out the shape.