The lower elevation of a layer is the lowest point of the layer (e.g., if you create a layer with a lower elevation of 2 microns, the layer begins at 2 and extends upwards until it reaches the Upper Elevation value). A signal layer's Lower Elevation value indicates its elevation above zero. Lower elevation can only be changed on signal layers in non laminate stackups.
To set a layer’s lower elevation:
- From the Edit Layers window, in the Lower Elevation column, double-click a layer’s Lower Elevation field.
- Type a value and its units in the field. The value can be specified using a number (e.g., 0.5um), a variable (e.g., $H), or an expression (e.g., $H-0.5um+$W).
- Press Enter. The layer is assigned the lower elevation you entered.