Importing IDF Files 

Icepak and HFSS 3D Layout can import Intermediate Data Format (IDF) files that have been exported from an ECAD package. The IDF is a neutral file format that is supported by many ECAD packages (for example, Allegro from Cadence, Board Station from Mentor Graphics, and Visula from Zuken) and some mechanical CAD packages (for example, PTC Creo, SDRC/I-deas, and Unigraphics). You can import IDF 2.0 and IDF 3.0 files into Icepak or HFSS 3D Layout. Note that IDF 4.0 files cannot be read by either Icepak or HFSS 3D Layout. This is because, currently, ECAD and CAD packages do not export to the IDF 4.0 format, due to the changes from IDF 3.0 to IDF 4.0.

Overview of Importing IDF Files

IDF 2.0 consists of two files, a board file and a library file. IDF 3.0 may consist of two or three files: a board file, a library file, and (in some cases) a control file. The board file contains information about the outline of the board, its thickness, and the positions (but not the sizes) of the components on the board. The library file contains information about the components of the board: their sizes, and their thermal and electrical properties. Icepak and HFSS 3D Layout needs both of these files to obtain complete thermal information about the board and the components. The control file contains information about the placement of boards in a rack.

Note that IDF 2.0 is a simpler format than IDF 3.0. For example, information such as junction-to-case thermal resistances and operating power information can be found only in an IDF 3.0 file.

When importing an IDF file, you can choose to filter out devices by height, power, or type, while optionally choosing to retain the filtered devices as non-model objects. Board conductivity properties, such as board thickness and materials assignment, can be specified and are used to calculate the orthotropic conductivity for the board. The IDF import workflow also allows you to specify a cut-off height for devices when the default height in the IDF file is large. And, if desired, you can select to import the board and devices as simple rectangular objects.