COMSOL 6.2 - Commands

Commands

Import of ECAD Files

Purpose

Import geometry objects from an ECAD file in 2D and 3D using the ECAD Import Module

Syntax

model.geom(<tag>).feature().create(<ftag>,"Import");

model.geom(<tag>).feature(<ftag>).set(property,<value>);

model.geom(<tag>).feature(<ftag>).getType(property);

model.geom(<tag>).feature(<ftag>).getStringMatrix("layerprop");

model.geom(<tag>).feature(<ftag>).importData();

Description

Use model.geom(<tag>).feature().create(<ftag>,"Import") to create a geometry import feature.

When the property filename is set to a file recognized as an ECAD file, the property ecadtype is automatically initialized to either gds, ipc2581, or odb++. The following properties are available:

Table 3-1: Valid Property/Value Pairs.
Property	Value	Default	Description
ecadtype	gds \| ipc2581 \| odb++ \| unknown	unknown	Type of ECAD file. A read only property that is automatically initialized from the property filename.
elevation	String[]	Empty	Z-position of layers.
filename	String	Empty	Filename.
fileunit	String	Empty	The length unit in file. Read only.
grouping	all \| layer \| none	layer	The grouping of the imported layers, where all returns one single object, and layer gives you one object per layer. For the import of GDS files the use of all is not recommended. In 2D, all is the same as layer.
height	String[]	Empty	Thickness of layers.
importlayer	String[]	Empty	The entries in the array govern if the corresponding layer is to be imported. Each entry value is either "on" or "off".
importtype	full3d \| shell	full3d	Determine if metal layers are imported as solid or faces in 3D.
intbnd	on \| off	off	Keep interior boundaries on layers.
layername	String[]	Empty	The user names for the layers. Empty string implies the name is taken from the ECAD file.
repairgeom	on \| off	on	Repair imported objects.
repairtol	double	1e-5 (for GDS) 1e-6 (for ODB++ and IPC-2581	Repair tolerance, relative to size of union of imported objects. Setting this property will automatically set repairtoltype to relative and repairgeom to on.
repairtoltype	auto \| relative	auto	Determine if repair tolerance is set automatically or manually by the repairtol property.
ignorecontvtx	on \| off	off	Ignore vertices with continuous tangent in layers. Only used when type is ecad.
contangletol	double	5 or 5[deg]	Continuous tangent tolerance. Only used if ignorecontvtx is on.
elimshortedg	on \| off	off	Eliminate short edges by ignoring vertices in layers. Only used when type is ecad.
maxedglen	double	0	Maximum edge length. Only used if elimshortedg is on.
selresult	on \| off	off	Create selections of all resulting objects.
selresultshow	all \| obj \| dom \| bnd \| edg \| pnt \| off	The highest available entity level except obj; usually dom.	Show selections of resulting objects in physics, materials, and so on, or in part instances. obj is not available in a component’s geometry. dom, bnd, and edg are not available in all features.
sellayer	on \| off	on	Create layer selections.
sellayershow	all \| dom \| bnd \| off	all	Show layer selections in physics, materials, and so on, and in part instances (when sellayer is on). This property is not available in a work plane’s Plane Geometry.
updategeomunit	Boolean	true or false	The default is true if the feature is the first in the geometry sequence, otherwise false. If true, the geometry sequence unit will be updated to the fileunit value when performing the import.
contributeto	String	none	Tag of cumulative selection to contribute to.
createselection	on \| off	off	Create selections.

The file specified by filename can be of any of the following formats:

Table 3-2: Supported File Formats.
File Format	File Extensions	ECADType
GDS	.gds	gds
IPC-2581	.cvg,.xml	ipc2581
ODB++®	.zip, .tar, .tgz, .tar.tgz	odb++

The imported objects are represented using COMSOL’s geometry modeler.

The property ecadtype determines which properties are available, see Table 3-2 for supported types. The property ecadtype is read only, and it is automatically initialized from the property filename, according to Table 3-2.

The property importlayer determines which layers to import. It is a string array of the same length as the number of layers, holding the strings on or off. The property is initialized with a valid default when setting the property filename.

To inspect available layers in a file, use the method

model.geom(<tag>).feature(<ftag>).getStringMatrix("layerprop");

It returns a String[][], with the same number of rows as the number of layers, that contains information about each layer.

The property height determines the height of all layers. It is a string array of the same length as the number of layers, holding string representations of the layer height, for example 1[mm]. The property is initialized with a valid default when setting the property filename.

The property elevation determines the Z-position of all layers. It is a string array of the same length as the number of layers, holding string representations of the layer elevation. Read more about how this property is initialized with a valid default for the supported formats in the following sections:

•

Import of GDS Files,

•

Import of ODB++ and IPC-2581 Files.

If selresult is set to on, a selection is created for all resulting entities of each type (object, domain, boundary, edge, and point), for use in the geometry sequence. To access the object selection, use model.geom(<tag>).selection(<ftag>), where <tag> is the geometry tag and <ftag> is the feature tag. To access the other selections, use model.geom(<tag>).selection(<ftag>.<lvl>), where <tag> is the geometry tag, <ftag> is the feature tag, and <lvl> is one of dom, bnd, edg, or pnt. If, in addition, selresultshow is set to a value other than off, all or some of these selections appear for use outside the geometry sequence. To access these selections, use model.selection(<tag>_<ftag>_<lvl>), where <tag> is the geometry tag, <ftag> is the feature tag, and <lvl> is one of dom, bnd, edg, or pnt.

If sellayer is set to on, a selection is created for all resulting entities of the types object, domain, and boundary, of each layer, for use in the geometry sequence. To access the object selections, use model.geom(<tag>).selection(<ftag>_<otag>), where <otag> is a tag derived from the name of the imported layer. <otag> is derived by replacing space and dot characters with underscore characters and removing other characters that are not numbers or uppercase or lowercase English characters (A–Z and a–z). Additionally, if required to make <otag> unique, _<m> is appended, where <m> is an integer. To access the other selections, use model.geom(<tag>).selection(<ftag>_<otag>.dom) or model.geom(<tag>).selection(<ftag>_<otag>.bnd), where <otag> is a tag derived from the name of the imported layer. If, in addition, sellayershow is set to a value other than off, all or some of these selections appear for use outside the geometry sequence.

To access these selections, use model.selection(<tag>_<ftag>_<otag>_dom) or model.selection(<tag>_<ftag>_<otag>_bnd), where <otag> is a tag derived from the name of the imported layer.

Import of GDS Files

If the file type is GDS, you can create additional selections for each imported cell by using the properties selcell and selcellshow.

Properties that are only available when ecadtype is gds.

Table 3-3: Valid Property/Value Pairs for GDS.
Property name	property Value	Default	Description
arcdistancetol	double	0.3	Tolerance for segment length deviation.
arcmaxangle	double	36	Maximum angle for segments.
arcminangle	double	3.6	Minimum angle for segments to part of an arc.
arcmaxcircledev	double	1e-3	Maximum allowed point deviation from a circle, relative to the circle radius.
arcradiustol	double	0.4	Tolerance for arc curvature.
cell	String	Empty	Name of cell to import. The top cell is imported by default.
cellfilter	String	Empty	Name of cell to include. Leave empty to include all cells below the cell selected by the cell property.
findarcs	auto \| manual \| off	auto	Control arc recognition.
findlines	on \| off	on	Turn on straight line recognition. Only available when findarcs is manual.
manualelevation	on \| off	off	Manual control of elevations.
selcell	on \| off	off	Create cell selections.
selcellshow	all \| dom \| bnd \| off	dom	Show cell selections in physics, materials, and so on, and in part instances (when selcell is on). This property is not available in a work plane’s Plane Geometry.
splitbydatatype	on \| off	off	Treat datatypes as separate layers

The property manualelevation controls how imported layers are positioned in the Z direction. When manualelevation is off, the imported layers are stacked on top of each other with no gaps, so the Z-positions are computed from the height property. When manualelevation is on and grouping is set to layer or none, the imported layers are positioned in the Z direction as specified by the elevation property. To switch to manual control of elevations it is recommended to first set manualelevation to on, then set the values for the height and elevation properties.

The property elevation is initialized with a valid default on these occasions:

•

when setting the property filename,

•

when setting the property manualelevation to off,

•

when manualelevation is off, and the value of the height property is changed,

•

when manualelevation is off, and the value of the importtype property is changed.

When findarcs is auto or manual, line segments are combined to form arcs. If findarcs is manual, the properties arcdistancetol, arcradiustol, arcminangle, arcmaxangle, and findlines can be used to tune the arc recognition algorithm, otherwise the algorithm tries to determine optimal parameters.

Import of ODB++ and IPC-2581 Files

Properties that are only available when ecadtype is ipc2581, odb++.

Table 3-4: Valid Property/Value Pairs for IPC-2581 and ODB++.
Property name	property Value	Default	Description
dielectric	on \| off	on	Import dielectric regions
elevationtype	metalabove \| metalbetween \| manual	metalabove	Select how elevations should be determined.
ignorelinewidth	on \| off	off	Import line symbols as curve objects by ignoring the line width during import
ignoreoffset	double	-0.1[mm]	Offset used when ignoreoutsideboard is on. The file unit is used if no unit is specified.
ignoreoutsideboard	on \| off	off	Ignore objects for which the defining points fall outside the board boundary incremented with the offset defined by ignoreoffset
ignoretext	on \| off	on	Ignore objects marked as text in the files
selnetkeepbnd	on \| off	false	Keep boundary net selections
selnetkeepdom	on \| off	false	Keep domain net selections
selnetnamebnd	String[]	Empty	Names of boundary net selections (read only)
selnetnamedom	String[]	Empty	Names of domain net selections (read only)
selnettagbnd	String[]	Empty	Tags of boundary net selections (read only, hidden in GUI)
selnettagdom	String[]	Empty	Tags of domain net selections (read only, hidden in GUI)
selnetcontributetobnd	String[]	Empty	Tags of cumulative selection to contribute to (or none to not contribute), for boundary net selections
selnetcontributetodom	String[]	Empty	Tags of cumulative selection to contribute to (or none to not contribute), for domain net selections
selnetshowbnd	on \| off	off	Show boundary net selections in physics, materials, and so on; in part instances; or in 3D from a plane geometry
selnetshowdom	on \| off	off	Show domain net selections in physics, materials, and so on; in part instances; or in 3D from a plane geometry

The property elevationtype controls how imported layers are positioned in the Z direction. When elevationtype is metalabove or metalbetween, the imported layers are stacked on top of each other with no gaps, so the Z-positions are computed from the height property. When elevationtype is manual and grouping is set to layer or none, the imported layers are positioned in the Z direction as specified by the elevation property. To switch to manual control of elevations it is recommended to first set elevationtype to manual, then set the values for the height and elevation properties.

The property elevation is initialized with a valid default on these occasions:

•

when setting the property filename,

•

when setting the property elevationtype to metalabove or metalbetween,

•

when setting the property elevationtype to manual,

•

when elevationtype is metalabove or metalbetween, and the value of the height property is changed,

•

when elevationtype is metalabove or metalbetween, and the value of the importtype property is changed.

You can use the net selection tag as a key when setting array elements in the other properties by using set(property,<ntag>, value), where <ntag> is a tag derived from the name of the net selection.

To access net selections, use model.selection(<tag>_<ftag>_<ntag>_dom) or model.selection(<tag>_<ftag>_<ntag>_bnd), where <ntag> is the tag of the net selection.