You are correct. A circuit design cannot be copyrighted. A PCB design can be, however. The PCB design is the actual layout of the copper traces on the board. I

You are correct. A circuit design cannot be copyrighted. A PCB design can be, however. The PCB design is the actual layout of the copper traces on the board. In the industry, it is referred to as "artwork" and is copyrightable as such.