Hello! This is the first time that I design a PCB from scratch. I am somewhat satisfied with the end result but, having no experience, before ordering the PCB I would like to have my design checked by more experienced people. Here is the project: [https://easyeda.com/LastStarDust/tdc-calibration-led](https://easyeda.com/LastStarDust/tdc-calibration-led) Only part of the schematics is shown (the whole schematics has already been tested using a breadboard so no need to worry about that). **I only need suggestions and corrections on the PCB part, please.** **In particular, are the corner screw holes correctly placed? I mean are they connected to the ground plane?** Thank you Giorgio