Defining Plated and Non-Plated Slots Unambiguously

A slot drawn as a line on a mechanical layer may communicate an idea without defining the hole that manufacturing must produce. Distinguish plated connector slots from non-plated openings and provide the actual machine-readable geometry. The two features may look similar in a viewer but require different fabrication handling.

Use the correct CAD feature

Altium’s pad and via documentation describes slot-shaped holes and separate drill outputs for hole kinds and plating status. It also notes limitations in how nominal rectangular holes are represented in manufacturing formats. Review the generated result rather than assuming a rectangular drawing becomes a sharp-cornered machined hole. Altium: pad holes, slots, and drill outputs.

Define the slot in the appropriate pad or fabrication feature, including plating status. State width, length, position, orientation, and the applicable finished tolerance. Clarify whether the length refers to the overall opening or another construction dimension. Identify the copper land required around a plated slot and the clearances required around a non-plated opening.

Check the actual component or mating feature

• Use the connector or mechanical-part drawing for the selected part number.
• Compare the tab’s limiting dimensions with the finished slot requirement.
• Include positional tolerance across an array of slots.
• Review internal corner or end-radius compatibility.
• Check the soldering or mechanical-retention requirement separately from simple fit.

For example, a flat connector tab may pass through a nominal slot while its rounded ends or tolerance stack leave insufficient assembly clearance at the limits. Enlarging the slot without checking the surrounding land can then create a solder-joint problem. Review both interfaces together.

Inspect the exported data

Load drill or route outputs with the copper and profile. Confirm that the slot appears as one intended operation, not as an unexplained series of overlapping holes or a decorative line. Verify that plated and non-plated files remain distinguishable and that the drill map agrees with them. If the fabricator requests a different representation, regenerate and inspect the agreed output.

Close fabrication questions explicitly

Ask the supplier to confirm the finished geometry and process when the slot is unusual or near its capability limit. Record the response with the drawing revision. Avoid duplicating contradictory slot outlines across several layers. A clear package contains one authoritative digital definition, supported by dimensions and notes that explain the functional requirement. This prevents a mechanically plausible opening from arriving without the plating or geometry the circuit actually needs.

Measure the slot end-to-end and across its width in the viewer; a toolpath centerline alone does not show its finished opening.