Importing GDSII (Stream/Calma)

Wirebond includes a GDSII importer that can handle the extremely large GDSII files from today’s chips. It does this by extracting only data on the specified pad ring layer (often known as the passivation layer) and flattening the data on-the-fly. The DieClean module then analyzes the pad ring layer and finds the centers of the pads. It automatically numbers the die pads and builds the required pad stacks. If net names are included as text under the pads, DieClean can pick these up and include them in the die netlist.

Very often the die designer supplies the package designer with a GDSII file that contains the pad openings. It is the package designer's job to somehow find the centers of the die pads and convert this data into a die netlist that can be used in a design software.

From the Wirebond pulldown select Import GDSII.

Use the Browse button to open a file section box and select the GDSII file you wish to process. Then press the Scan button to have the GDSII filter scan the file and determine what structures and layers are present.

After scanning the file the user can see the structures and layers available. Select the structure and layer to process using the drop down list boxes. (The die designer should have supplied you with the GDSII number of the pad ring layer.)

Then click OK.

The Imported GDSII Data

Below you can see the imported pad ring data. Each pad is a zero width closed polyline. The text and outline were already in the GDSII file. (they are there for example purposes only...normally you will have only the pad openings and possibly openings for alignment targets or die logo.