Glossary

Terminology used in LinkCAD and IC/PCB layout design.

Alias: Name associated with an entity such as an instance or net name. Many formats do not support aliases.
Aperture: Opening in a stencil corresponding to a land area on a circuit board. Defined by shape, size, and position.
Aspect Ratio: Ratio of aperture opening to stencil thickness. Should be > 1.5 for chemically etched stencils, > 1.2 for laser-cut, > 1.1 for electroformed.
Attribute: Named property attached to an object — instance name, net name, or physical value.
Cell: A named container of shapes and references to other cells. Cells form a hierarchy. Also called structure (GDSII) or block (DXF).
Cell Reference: A placed instance of a cell within another cell, with optional transformation (translation, rotation, mirroring, scaling).
Chamfer: A corner with the sharp edge removed.
Co-Linear Points: Points on a straight path that are geometrically redundant and can be removed without altering the shape.
Database: The in-memory data model containing all cells, layers, and shapes. Backed by a high-performance C++ engine.
Database Units: The internal measurement unit of a file. Common values: mils, microns, millimeters, nanometers.
Display Units: The unit shown in the UI. Can differ from database units via a scale factor.
Endpoint: The first or last vertex of a polyline.
Fiducial: A mark used by machine vision for alignment. Can be global (board-level) or local (component-level).
Fill: Rendering a closed polygon with a solid or hatched color interior.
Flatten: Collapsing a cell hierarchy into a single cell by resolving all cell references into their constituent shapes.
Geometry: Any geometric entity: polygon, polyline, circle, arc, or text.
Grid: A matrix of reference points at regular intervals, used for snapping coordinates.
Land: A conductive area on a PCB to which components attach.
Layer: A named grouping of shapes, displayed with a specific color. Layers can be toggled visible/invisible.
Layer Map: A mapping table that renames, merges, or filters layers during file conversion.
Line Segment: A portion of a polyline between two adjacent vertices.
Origin: The point at coordinates (0, 0) in the drawing.
Path: A polyline with an associated width. Also called a wire.
Polygon: A closed figure defined by three or more vertices. In LinkCAD, all closed polylines are filled as polygons.
Polyline: A series of connected line segments. Can be open or closed. A closed polyline with zero width is equivalent to a polygon.
Re-entrant Boundary: A polyline that crosses or touches itself.
Session: A snapshot of LinkCAD's state: open files, conversion settings, layer visibility, and viewer configuration. Saved as a .lcs file.
SHX Font: AutoCAD's native vector font format, supported by LinkCAD for text rendering. TrueType fonts are not used.
Stencil: A sheet of metal (usually stainless steel) with etched or laser-cut apertures for depositing solder paste.
Text: Character data placed in the drawing, rendered using SHX fonts.
Top Cell: The topmost cell in a hierarchy — the cell that is not referenced by any other cell. Also called the main cell.
Vertex: A point on a polyline or polygon boundary.
Wire: See Path.