Add a silkscreen Logo


#1

Create a Logo

The below describes the image processing pipeline we successfully used for adding a silkscreen logo to our PCB. There are lots of parameters and settings that influence what the final file
looks like and we had many false starts. The below is surely not the only way, and hopefully
others can comment on other/better ways to do this. Our platform is MacOS, but the below
tools are multi-platform and only the menus may vary.

Root .svg file

To create a logo, best is to start out producing a Scaleable Vector Graphics (.svg) file, using
e.g. (free) Inkscape. For inspiration you can take a photography or other image and trace paths.
Avoid thin lines, since they may not reproduce properly when size is scaled down.
Also consider whether text should be part of the logo, or can be added independently (text
has lots of thin lines that may need to be adjusted after some lossy image conversion steps.
The logo can be drawn at any size. In our case the .svg was drawn using paths and didn’t have text.

For use as a PCB silkscreen logo, only use a single color, and let the background be transparent.
Upverter has a peculiarity that it uses the color of the top leftmost pixel as the background color,
so if your logo foreground normally occupies this pixel, adjust the page size
(File->Document_Properties->Page. In the Custom size field choose “Resize page to content…” and
add 1px to each margin.)

Convert to .png

Use a raster file editor such as (free) Gimp to import the .svg file.
Set the image size to the desired size of the logo and choose a resolution so that no
jagged lines are visible. We used 80px/mm when producing a 5mm high logo and chose to
retain paths during import.
If result looks good, consider saving the intermediate result in Gimp native format
before doing rest of the steps.

Next need to convert to an image with a single bit color.
(Image->Mode->Indexed. Select option "black and white (1 pixel).
This should result in your logo being (solid black) with white background.
Check that there isn’t any “Alpha channel” (transparency) by looking at the right-hand side toolbar.
If there is, you can either delete this channel from toolbar, or
(Image->Flatten Image)

Next, save the file in .png format.
(File->Export As… ) At bottom of popup expand “Select File Type (By Extension)” and choose .png
Enter a descriptive file name incl image height and other options so that you can distinguish different attempts if first one doesn’t work.

Import into Upverter

On the PCB layout view, choose Art from the right side toolbar. In the popup, browse for the
just created .png and upload it. It will display on the right side of the popup and you can
choose which layer to place it on.
If you make several attempts, multiple files will be displayed and you need to pay attention
to file name, since Upverter doesn’t automatically select the latest one.
Upverter can display many image formats at this stage (including .svg and colored .png),
but that is not a good indicator if it will actually display on your PCB.
The list of imported files grows with each attempt, and there doesn’t appear to be a way to
remove old unused files.

If everything goes well, your logo should pop up on PCB just below origin and can thereafter be moved.
If you see a filled rectangle, something is wrong with image format. Go back and experiment with GIMP image settings.

If logo is inverse, the problem is likely you ndeed to add a 1px image border (see above)

The logo can be resized in Upverter, however this is not a very reliable method, since it appears the aspect ratio isn’t locked. Multiple attempts may also degrade the final image quality since .png is a lossy format. Zoom in to check that lines don’t look jagged (too low resolution
in rasterization step.)

There is currently no way to infer which file an imported logo relates to if you have attempted several, so keep notes of which one works and the exact steps and options
you chose.


#2

Thank for writing this up! we are working on a way to better show imported files


#3

umm i was able to import a png, but unable to move it . what could i be doing wrong? is there a hotkey to move the png?


#4

I will try importing a PNG to reproduce this.

the only thing I can think of off the top of my head is that you are have a different layer active … try pressing ` to deactivate a specific layer


#5

I had a chance to play with some imported PNGs, I cannot reproduce not being able to move them. Give the layer thing a try and let me know if it work.

Thanks,

Michael