I am currently working with the AD8233 chip for the acquisition of ECG signals, I have previously used the AD8232. In order to improve the product and decrease the size of the PCB, I have chosen to use the AD8233. The problem I have is the following: The pitch between the balls of the AD8233 is 0.4mm, this means that there can be no tracks between its pins, therefore I must use vias in pad.
I plan to use vias whose diameter is 8 mil. Now my PCB is 4 layers, my question is if I can use these vias in pad from the top layer to the bottom layer?
I am not very clear if this can be done, I have read a lot of the subject, but some recommend using blind vias that go from the top layer to the closest plane.
I would appreciate if you can give me information on how to solve this problem with the layout of the AD8233.