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What's in an AIF File?

This format is intended to describe the bond shell area of BGA, Flex, uBGA and other types of integrated circuit packages. It is also used by chip designers to define the pad locations, nets and size of their die. As a simple ASCII format it should be readable and writable by a variety of software. It enables companies to use in house programmers to generate custom manufacturing software.



AIF uses syntax similar to Microsoft Windows' INI files since reading and writing such files is something most programmers know how to do well.

A properly written parser will skip over any section that it does not recognize. This enables companies to extend the AIF format for their own use and not break properly designed AIF readers.

AIF Main Sections

The AIF file format is broken into multiple sections:

[DATABASE] - Identifies the file format,version and database units enabling programs that read AIF to be sure that they are loading an AIF file and that the version they are reading is compatible. REQUIRED

[DIE] - Describes the die outline size, and die name. The actual die pad information is located in the NETLIST section. REQUIRED

[PADS] - This section defines as many pad types as needed: pads for die openings, bond fingers and ball pads. Think of these as padstack definitions you would encounter in a EDA database except that there is no vertical layer information. REQUIRED

[NETLIST] - This section is the actual netlist. Each net is listed along with the associated die pads, fingers, balls and coordinates. REQUIRED.

[RINGS] - This section lists ring names and associates each ring name with a net. These are actually polygon definitions that support both dark and clear polygons. OPTIONAL

[BONDABLE_RING_AREA] - A specialized section that results from taking the intersection of the rings, fingers and alignment marks on the top metal layer with the solder mask. It is meant to better represent the areas that can be bonded as they are "exposed by the solder mask. OPTIONAL

[BGA] - describes the extents of the package, and itís name or reference designator. OPTIONAL

[WIRE] - this section defines the wire diameter. OPTIONAL

[FIDUCIALS] - This section describes the location of the fiducials and defines their shape and location. OPTIONAL

[DIE_LOGO] Used to place a die logo or id on the die. It is a polygon or series of polygons that can be used to form text, or other shapes used to identify the die. OPTIONAL

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