MLA150 - Large Image GDS Generation

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Instructions on how to take a regular rasterized image (eg. JPG, BMP, PNG etc.) and convert it into a vectorized format compatible with the MLA150. This produces a much smaller file than a raw BMP image, because large-area polygons are created, as opposed to defining each pixel across a 150mm wafer (which hits the RAM limit on the computer).

In this example, we convert the image into simple 1-bit black-and-white image using the free software GIMP, and then convert to a Vector format using the free software InkScape. Then we correct the scale and convert to GDS using the free software KLayout.

Procedure

GIMP: (can also do in another image editor, such as Paint.exe)

open the Image (JPG, PNG, BMP etc.),

Image > Mode > Indexed > 1-bit

Optional: Dither to handle grey values, haven't tried this.

Can edit by painting etc.

Save as any JPG, PNG, BMP format

Inkscape:

Open the Image file, default options

Click on the Image with the Arrow tool, to select it.

Path > Trace Bitmap (options affect curves/resolution)

- Use the “Update” button to show a Preview of the Path that will be created.

- Options: Trace BitMap > Single-Scan > AutoTrace (dropdown menu).  

- [OK] to create the Path, then Close the “Trace Bitmap” window.

- Creates a new Path object that outlines the image

Use the Arrow select tool to select the Image

- bottom bar shows what object is selected

- Option/Alt-Click to select obscured objects

- Make sure PATH is Not selected

Delete the Image.  File should have only the Path object in it.

File > Save a Copy… > DXF (Autocad R14)

> UNCHECK "Robo" and "LWPOLYLINE" - important, or the lines won’t be connected as a single object.

Klayout:

Open the DXF in Klayout

Use Cell Instance to scale up to desired size:

  • Create a new Cell
  • Instance the original Cell into that.
  • Edit Cell Instance properties to adjust scaling

Use Move tool to Center image at 0,0

Save as GDS

  • Change file extension to lower case “gds” important, or MLA convert software won’t see the file.

Take note of which Cell & Layer should be printed

MLA:

[Convert Design] and Import the GDS,

Choose correct Cell from dropdown

Set correct Layer: set 1st line to correct layer & uncheck the others

[Viewer] to make sure scale is correct

Ready to expose the pattern as normal.