The Cadence® import is initiated in Cadence Allegro® itself via the CST Allegro Plug-In. This allows the user to select an area, a net or an object in the layout or the full layout itself. Due to the potentially immense scale and complexity of circuit layouts it is important for the user to be able to control the size of the layout imported into CST MICROWAVE STUDIO® (CST MWS). An example of an import is shown in Figure 1.
An overview of the process and the supported features of the Cadence Allegro link is shown in Figure 2.
Before the full layout, area or net is exported from Cadence Allegro the cross-sectional package information can be checked and adjusted. Figure 3 shows the cross-section configuration table where the layer material, type, thickness, elevation and electromagnetic properties are set. Specific layers can be selectively included or excluded from the export....
In a similar manner, the package information can also be edited as shown in Figure 4 where BGA, die and bond wire components' properties can be checked. The parameters for the component types such as solder ball radii, height, elevation etc. can be specified.
Figure 5 shows the full layout, area and net import possibilities for the structure import. All component names and material properties are included as a result of the cross-section and package setups. All components are editable and can also be deleted or modified.
Finally, Figure 6 shows the feature where the structure can be automatically cleaned and healed. Since the PERFECT BOUNDARY APPROXIMATION, (PBA®) allows the efficient handling of rounded geometries, a facetted representation of these surfaces is not necessary. During the import process the user can control the level to which the healing is applied.
This article has only skimmed the surface of the very powerful import facilities available for Cadence Allegro structures which enable, with minimal user-interaction, the seamless importing of complicated multilayer and packaging structures.