Break-off tabs

The Panelization module supports two kinds of break-off tabs. Edge tabs are tabs placed along the edge of a board. Corner tabs are placed at the corner of a board.

Edge tabs may be removed by breaking, cutting or milling the tab. Milling is the safest method for removing tabs. Breaking or cutting a tab may lead to damaged solder joints, especially on surface mounted components near the break-off tab. When a corner tab is placed at the corner of all adjacent boards (i.e. not along the edge of a neighboring board) then it can be removed by drilling rather than by cutting the tab. See the Depanelization chapter for more info.

Tab length: This value specifies the length of the tabs. For edge tabs, this is the length of the narrowest point on the tab. For corner tabs, the width of the narrowest point is about 40% of the specified tab length.

Holes: A row of “mousebite” holes may be added to tabs. Diameter, spacing and offset of the holes may be specified. The number of holes is determined automatically. Mousebite holes are not added to corner tabs.

Remove soldermask: If checked, solder mask will be removed from around each break-off tab and its mousebite holes (if any). This helps prevent cracks in the solder mask when cutting the tabs. Note: Removing the solder mask may expose copper near tabs. Check all tabs carefully.

Autoplace: This function places tabs at the midpoints or corners of each board's outer contour. For boards with curved edges, the endpoints of arcs are treated as corners.

For boards with complex contours and for multi-product panels, autoplacement may give undesirable results.

Manual placement: To place tabs manually, click on the Place button (so that it is “down”).

When you click and drag the mouse pointer, a horizontal or vertical line appears. When you release the mouse button, tabs will be placed at each point where the line crosses a board edge.

Alternatively, tabs can be placed one at a time. Clicking on the edge of a board will place tabs at that position on each instance of that board in the panel. To place a tab on only one board, hold the Ctrl key down while clicking to place the tab.

For wave soldered panels, you should add at least one break-off tab to inner contours so that the material will not be removed during production.

Tab removal: To remove all tabs, click on the Clear all button.

To remove individual tabs, click on the Remove button (so that it is “down”). Left-click and draw a selection rectangle around the tab(s) to remove. All tabs at that position on all boards in the array will be removed. To remove a tab from only one board, hold the Ctrl key down while removing the tab.

Note: If a multi-product panel is specified without any tabs, the boards within the panel will be delivered as individual boards rather than as a panel. (A single-product panel may not be specified without tabs.)