I had two of my PCs captured by the Empire last session. Now I need a couple of good maps for a prison break mission.

http://cards.boardwars.eu/Skirmish-Maps/

You could probably slice these maps up and use their tiles up to make something that’ll work. Just ignore the grid lines when playing.

And, a quick google scored this.

Check out the WEG Death Star Technical Companion . Included in it is a layout of a typical Imperial detention block.