minEdgeLength

Sets the minimum edge length for a shape on the layer.

minEdgeLength Quick Reference

Value Type

minEdgeLength constraints have a Value that represents the minimum edge length in user units.

Parameters

The minEdgeLength constraint has these optional parameters:

• lengthSum (Value) specifies that the constraint does not apply if the sum of consecutive edges that are shorter than the minimum edge length value is less than the value of this parameter.
• cutToMetalSpacing (Value) specifies that the constraint applies only when there is a cut shape (enclosedCut) on the layer above or below the metal layer that is less than or equal to this distance from the metal edge.
• enclosedCut (StringAsIntValue) specifies which cuts are considered with cutToMetalSpacing as given in the following table.
  
  enclosedCut Values

  String	Integer Value	Constraint applies when:
  cutIsAboveAndBelow	0	Cut shape on layer above or below
  cutIsBelow	1	Cut shape on layer below
  cutIsAbove	2	Cut shape on layer above

Examples

Example1—minEdgeLength without lengthSum

This example sets the minimum edge length for shapes on Metal1 to 1.0.

set_layer_constraint -layer Metal1 \
  -constraint minEdgeLength -Value 1.0 -hardness hard

MINSTEP 1.0 STEP ;

The following figure illustrates how the constraint setting affects three shapes.

Example2—minEdgeLength with lengthSum

This example sets the minimum edge length for shapes on Metal1 to 1.0 and excludes consecutive minimum steps whose total length is less than 1.1.

set_constraint_parameter -name lengthSum 1.1
set_layer_constraint -layer Metal1 \
  -constraint minEdgeLength -Value 1.0 -hardness hard

LAYER Metal1
  MINSTEP 1.0 STEP LENGTHSUM 1.1 ;

Using these settings for minEdgeLength and lengthSum, shapes b and c in the following figure are legal. For shape b, the consecutive edges that are shorter than minEdgeLength have a total length of 1.0, which is less than the lengthSum value, so the constraint is not applied. Shape a is a violation because the total length of the consecutive minimum length edges is greater than the lengthSum value.

Illustration of minEdgeLength with Cut Shape Dependency

This example sets the minimum edge length for shapes on Metal2 to 0.025 whenever there is a cut shape on the layer above the metal that is less than or equal to 0.04 from a Metal2 shape.

set_constraint_parameter -name cutToMetalSpacing -Value 0.04
set_constraint_parameter -name enclosedCut \
  -StringAsIntValue cutIsAbove\
set_layer_constraint -layer Metal2 -constraint minEdgeLength \
  -Value 0.025

Related Topics

Length and Width Constraints