I am new to Kicad (the project I am working on is only my 3rd board). My current project involves designing a custom PCB for use with very small GMR (giant magnetoresistance) sensors, and in my specific case I require a trench (or hole between specific layers) in a 4 layer PCB. The sensors are placed on the back of the PCB (4th layer), while there is also a current trace passing beneath them on the same layer.
I require a trench or hole between the front layer and the 3rd one (such as only the back layer and corresponding insulation layer) remains. From my understanding, my problem will be solved easily If I can define a custom shape blind via (square or rectangular) or NPTH passing between those specific layers but I haven’t been able to find how you can define that in Kicad (in the footprint editor or PCB layout).
Can you guide me through a step by step process on how I would be able to do so?
Thank you in advance.
P.S. Let me know if more details are required.
P.P.S. I am using the latest version of Kicad (5.1.5.)