DefSpace contains the definitions of template objects and more complex design objects. One can think of it as a library area where items that will be referenced or used later are contained.

(DefSpace
 (Pad)
 (PackageDef)
)

PAD

A Pad is simply a named shape. It forms the building blocks of Pins, PinDefs and Buffers. The Pad requires a unique name and should have a shape associated with it.

(Pad  
 (Name SQ_50)
 (Shape)
)

Shape

The Shape object is used universally throughout the AIF format to define any regular geometrical or polygonal shape.

(Shape
 (Type CIRCLE)
 (Width 50)
)

(Shape
 (Type SQUARE)
 (Width 50)
)

(Shape
 (Type RECTANGLE)
 (Width 200)
 (Height 50)
)

(Shape
 (Type OBLONG)
 (Width 200)
 (Height 50)
)

(Shape
 (Type POLYGON)
 (Polygon
  50 -25 
  -50 -25 ARC -1
  -50 25 
  50 25 ARC -1
 )
)

Notice how the polygon definition defines an oblong by specifying arc segments with the AutoCAD bulge value after the ARC keyword. Arc support was not included in AIF v2.0, but AIF v3.0 does support arcs. The polygon definition (unlike GDSII) assumes that the last coordinate point returns to the first point.

The Shape object also supports the following properties:

(Shape
 (Chamfer 5)
 (BasePoint 0 0)
 (Rotation 0)
 (Scratch NO)
)

The chamfer property is as defined in AIF v2.0 and can only be attached to SQUARE and RECTANGLE shapes. Any shape can use a BasePoint and Rotation property. The Scratch keyword, which can be YES or NO, is used with Metal objects to define whether a particular shape is a piece of metal or a hole in the metal.