Glossary

Terminology used in LinkCAD and IC/PCB layout design.

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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.