A via is an object that extends in the z direction and connects two signal layers, allowing a signal to travel from one layer to another. Unlike cross-layer plates, vias have volume, can be electrically large, and vary in shape. For these reasons, vias also use greater computational resources than cross-layer plates.
Vias are created from two 2D objects. Each 2D object is located on a trace layer. The via is extruded between the 2D objects when a mesh is generated, thereby connecting the layers.
Vias can also be 2.5D, 3D, or created from primitives drawn on a padstack layer (i.e., circles, polygons, arc, or lines).
2.5D Vias
2.5D vias must have a circular cross-section and be strictly vertical. A 2.5D via has a finite radius and the current is assumed to be flowing along the surface of the via. The current flow is assumed to be strictly vertical; Electronics Desktop treats the via as a 1D wire connecting the two layers. All 2.5D vias have a default complex load impedance of zero.
3D Vias
3D vias can be any shape, but the 2D objects they connect must have the same number of edges. The current is assumed to be flowing on the surface of the via in all directions.
3D vias may contain voids. Voids in 3D vias can be placed entirely or partially in the outer contour. No attempt is made to geometrically align voids in upper polygons with those in lower polygons. Instead, the order in which voids on different layers are created is used to control their alignment.
Drawing a Cross-Layer Plate in the Layout Editor
After selecting two or more objects on different layers, navigate to Draw and select Create 3D Structure to connect the objects and create a single 2D or 3D object. The selected objects must possess the same number of points. If the selected objects contain open lines, the created structure will include a two-dimensional face (i.e., cross-layer plate) that spans the different layers. If the selected objects contain closed lines, the structure will include a three-dimensional solid (i.e., 3D Via) that spans the different layers. These 3D surfaces are included in the Planar EM model. 3D structures also possess material attributes.
Drawing a Hole in the Layout Editor
A hole is a placeholder created while drawing a via. To create a void, or remove material from an object, refer to Drawing a Void in the Layout Editor.