Via Grouping and Snapping in XML Control Files (ECAD Xplorer)

When importing a GDSII file through ECAD Xplorer, the XML control file can designate via layers. These layers may have options for materials, target layers, and where their vias start and stop. Via grouping and via snapping can also be configured in the XML so that those operations occur automatically during import.

<Vias> tags are child elements of the <ELayers> tag and define the via layers. The order of child tags and records in <ELayers> matters and must be in this order: <Dielectrics>, <Layers>, then <Vias>.

<ELayers> can contain an option to automatically snap primitives. Add the option MetalLayerSnappingTolerance to set the maximum distance for moving primitives when aligning them. Its value is a string in the form “#<unit>”.

<Vias> contain <Layer> tags that are similar to other <Layer> tags but with these differences:

StartLayer option is required. This is a string that names the reference (signal) layer where the via starts.
StopLayer option is required. This is a string that names the reference (signal) layer where the via ends. If string is empty, the layer is treated as a cut layer and vias are generated between all layers below the start layer with matching geometries on both the start and stop layers.
GDSDataType is permitted.
No GDSIIVia option.
No Type option.

<Layers> may have these child elements:

<CreateViaGroups> automatically creates groups of vias when the GDSII file is imported with this XML tag. Its options are:
- Method groups vias by considering their spacing or if they are within a tolerance distance. Acceptable values are proximity|range.
- Persistant is whether to keep the original primitives of a via group in the layout. Acceptable values are true|false.
- Tolerance is the maximum distance for grouping vias. A string value in the form “#<unit>”.
- CheckContainment is whether to detect and prevent electrical shorts. Acceptable values are true|false.
<SnapViaGroups> automatically aligns vias across layers when the GDSII file is imported with this XML tag. Its options are:
- Method is whether to align vias within a specified area or distance of a selected object. Acceptable values are areafactor|distance.
- Tolerance is the value used to determine the maximum amount via groups are snapped by. Enter a numerical value in quotes. See Snapping Vias for how the tolerance is used in different via snapping methods.
- RemoveUnconnected is whether to delete vias that have no connectivity or have connectivity only to a single layer. Acceptable values are true|false.

Example Control File

<?xml version="1.0" encoding="UTF-8" standalone="no" ?>

<c:Control xmlns:c="http://www.ansys.com/control" schemaVersion="1.0">

</Permittivity>

</DielectricLossTangent>

</ThermalConductivity>

</ThermalExpansionCoefficient>

</MassDensity>

</YoungsModulus>

</PoissonsRatio>

</Material>

</Permeability>

</Conductivity>

</ThermalConductivity>

</ThermalExpansionCoefficient>

</MassDensity>

</YoungsModulus>

</PoissonsRatio>

</Material>

</Materials>

</Dielectrics>

</Layers>

</ELayers>

</Stackup>

</c:Control>