Introduction

Wafer maps are used in the back end of the IC manufacturing industry to annotate the die on a wafer - the annotation may indicate the die's identity, whether the die is good or bad or the "grade" of the device.

WaferMap Convert has two functions: 1) as an aid to create the layout for bump redistribution circuitry that is added to the wafer after the regular manufacturing is completed; 2) to convert a map file in one format to another format.

 

SINF formatted wafer map


Many Different Formats and Syntax

While the basic data of a wafer map is fairly simple, foundries that provide mask data (and equipment that reads map data) do not adhere to a single standardized format. This means that any software utility designed to convert such files must support a number of different formats.

Supported Input Formats

The formats currently supported by Wafermap Convert are listed on this page: Supported Formats

If your format is not supported, please send us a sample and documentation (if needed) and we will determine whether it can be added.


Supported Output Formats

WaferMap Convert supports a number of different output formats:

SINF

3 DIGIT SINF

WWF

IBIS (XML)

SEMI E-142


Incomplete Data?

We have encountered wafer maps that lack essential data needed to create a physical layout -- for example, some maps are missing the step size of the die. This information must be manually entered in order to actually produce a layout. Fortunately the step size is fairly easy to obtain and enter manually.

Most wafer map formats do not provide physical offset information -- that is, if you find the center of the array and place that at the center of the wafer, you may find that a small offset is needed in order that the good die don't fall past the wafer's boundary (or the boundary - margin.)


Standard Formats for Wafer Maps

Over the years standard's groups have defined wafer map formats in order to help the industry exchange data more efficiently. These include:


The WMapConverter Utility

WMapConverter reads a number of different map file formats and produces any (or all) of the following outputs:

    Standard SINF ASCII Wafer Map

    DXF Layout

    GDSII Layout


WMapConverter main dialog


WMapConverter Die Dialog shows count and allows ID remapping


How it WMapConverter Works

The user loads the wafer map file and uses the pulldown to indicate what "flavor" of wafer map is to be converted. (See supported map formats ...) Once loaded the user presses the Scan ... button.

Input Parameters

After the input file is scanned, WMapConverter displays the critical input parameters in this section. If a particular flavor of map file is missing one or more parameters, the user needs to enter those values. This might be the stepping information, the units or the position of the wafer notch. Row and Column data can always be determined by the program for a valid wafer map file.

Output

The user selects the directory for the output file along with the "base" name. The output name will use the base name plus an extension: txt for sinf files, gds for GDSII stream and dxf for DXF file.

The user can also select the units of the output file.


Transformations

Rotation - The data can be rotated clockwise about the center in increments of 90 degrees. This is useful when the foundry provides the data with the notch in one position (say on the left side) but the RDL designer works with the notch in another position (say on the bottom.)

Move - since the wafer map has no positional information the entire array is intially centered about 0,0. However it is rarely the case that the array is actually centered 0,0 on the wafer. Therefore the program allows the user to add a shift to position the array exactly where it should be on the wafer.

Unfortunately, determining the correct value of shift is not always easy given the nature of the data provided by the wafer foundry. We'll discuss ways of determining that.


Die ID Remapping

The SINF map file format has strict requirements for the ID values of each die. Other map formats don't follow these restrictions so it becomes necessary to remap those into legal SINF values. The layer dialog not only provides the user a quantity for each Die ID, it allows the user to change the ID in the converted output.

For example:
Input Map  -->   SINF Map
   *       -->     __
   X       -->     01

Special Graphical Elements

The actual size of the wafer is not part of the wafer map specification. The user can enter the wafer diameter and margin and also have cross hairs drawn in the GDS and DXF Output. These additional items make it much easier to make measurements in the layout.




Download Revision History Video Tutorials Price




ARTWORK CONVERSION SOFTWARE, INC.                  Company Profile
417 Ingalls St.,     Santa Cruz, CA 95060         Tel (831) 426-6163     Fax 426-2824               email: info@artwork.com