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Introduction

Image to Die Netlist is a set of programs designed to convert a "snapshot" of a die's surface into a die pad netlist. It is an extension of Artwork's Smart Die software which is used to identify die pads from a GDSII database. However, because the image is noisy, we had to add a number of algorithms to condition the data so that the netlist does not include noisy pad sizes or coordinate centers.

snapshot of die surface

Snapshot of die surface (grayscale bitmap)

This program was developed for an end-user who needs to design packages and the associated bond wire document for legacy chips; chips to which they don't have a GDSII or other CAD drawing.

So a high resolution images is taken of the device (say 0.5 um resolution) and this image is first processed (typically using Photoshop) into a high contrast black and white image. The new bitmap is converted into GDSII using Artwork's tiff2gds module. The resulting GDSII is still too "noisy" to be useful so a filtering program (GDSFILT) is used to remove polygons that are not die pads.

Finally, the irregular polygons that form the die pads are "cleaned" up, the size and centers extracted and the die pads numbered.

The results are saved as a text file that includes each die pad, its die pad number and its X,Y coordinate.


Platform

Windows 10/11 64 bit

requires:
AutoCAD 2018-2023

requires:
Photoshop or Equivalent



How it Works

image to die netlist flow

Image/Bitmap Processing

The starting point is a high resolution image of the die surface. The image can be in RGB color or grayscale. Because the pad openings are not covered by the passivation layer, the reflection from the openings should be "brighter" than the rest of the surface (except possibly for die logo) However because the passivation is so thin, the difference in "brightness" between pad openings and the rest of the surface is often quite small.

Photoshop is used to convert the incoming image into a black and white TIFF bitmap

TIFF2GDS converts the bitmap into a GDSII file; GDSFILT does polygon filtering to remove polygons that don't resemble pads; PadClean is used to remove noise in the die pads; Die Clean is used to produce the netlist from the cleaned up die pads.

Details ...