Card contour cutting line:
Unfortunately, we use a line to draw the outline of the design without considering the width of the strokes used, if the cutting process is performed on the outside of the line and we start from the center or inside her. Depending on the width of the production line, if the cards are designed to be very precise, these cards may not be completely correctly assembled into the box or chassis once the circuit is assembled, resulting in an additional mechanical adjustment process after the card is manufactured.
One way to avoid this confusion is to draw the external cutting line with very thin lines to minimize the impact of the way the manufacturer cuts the circuit. In addition, it must have the following characteristics:
The trace width used for the cutting line should be 0.01mm.
It must be a continuous line that surrounds the entire final periphery of the printed circuit, and its most terminal must coincide with its initial end.
The strokes should not overlap on the same line.
You should not play any copper pads, railroad tracks or airplanes.
Ideally, the distance between them should be at least 2mm. In order to avoid affecting the performance of the pad when the circuit is assembled in the form of a cutting panel.
The start and end points of the cutting line must coincide at the same grid point.
Manufacturers usually use a 2.4 mm diameter tool to cut the printed circuit through the wiring method, which will pass through the outer edge of the cutting line designed by the user. The above recommendations allow cutting with an accuracy of +/- 0.01 mm plus the manufacturer's tolerance. Designing the cutting line to be so thin (0.01 mm) will ensure that this size will not affect the final size of the card.
Slot and internal card slot cutting line:
The previous considerations are valid for any type of cutting implemented within a printed circuit board, such as in the case of slots. The distance to its edges, traces, pads, and copper planes should all be considered as the external cutouts of the card, which is crucial because the manufacturer will use the same steps in both cases.
