A component carrier includes (a) a first stack with at least one first electrically conductive layer structure and/or at least one first electrically insulating layer structure; (b) a hole formed within the first stack; and (c) a non-deformable solid body closing a portion of the hole and being spaced with respect to side walls of the hole by a gap. A component carrier assembly includes (a) a component carrier as described above; (b) a second stack having at least one second electrically conductive layer structure and/or at least one second electrically insulating layer structure; and (c) a connection piece connecting the first stack with the second stack. Further described are methods for manufacturing such a component carrier and such a component carrier assembly.