I am trying to wrap my head around the structure of a multilayer PCB, and while I can understand many things, I am not able to grasp the concept of "prepreg" and "core". What do they exactly do? I have attached a reference stackup below.
Only thing I understand about them is that they are used to glue the layers together. But why both, why not only "prepreg" or "core"? How do they differentiate from each other?
Could you please demystify these things for me?
Any good reference to understand this and how the layer stackup is determined is also appreciated.