This topic describes the use of the Positive/Negative layer to make an internal layer multi-power design. The internal layer power/ground design can be executed using the Powerplane layer or the Positive/Negative layer.
Powerplane layer
The Powerplane layer refers to a conductor layer for which the whole area fill is set as one net. The Powerplane layer is used as a ground or power area fill in general use, and handled as a negative image layer in terms of manufacturing. Only thermal and clearance lands can be generated on the Powerplane layer.
Positive/Negative layer
The Positive/Negative layer is used to make a multi-power design, and is also used to route track patterns of another net on the power/ground layer. When the packaging density is lower, or the number of layers is sufficient, the Powerplane design can be used. However, with the high board density and advanced high-level functionality, the Positive/Negative mix design is more effective for routing track patterns on the internal layer, and to create a multi-power design. On the Positive/Negative layer, when a via that passes through the layer encounters an area fill pattern, the land is automatically set to a thermal or clearance land which is defined in the padstack definition.
