Multilayer substrate including insulating layers, signal conductive layers and ground layers and having through holes extending along intersecting directions

A multilayer substrate comprising:

• a multilayer body;
• a plurality of layers stacked on each other in an up-down direction of the multilayer body;
• wherein
• the plurality of layers include:
• at least one insulating layer;
• a first spacer;
• a first ground conductive layer located above the first spacer in the up-down direction of the multilayer body;
• and
• a signal conductive layer overlapping the first ground conductive layer and located below the first spacer, as viewed in the up-down direction of the multilayer body;
• a plurality of first through-holes passing through the first spacer in the up-down direction of the multilayer body are provided in the first spacer;
• a first direction that is parallel or substantially parallel with a first straight line extends along the first spacer, as viewed in the up-down direction of the multilayer body;
• a second direction that is parallel or substantially parallel with a second straight line, which is not parallel with the first straight line, extends along the first spacer, as viewed in the up-down direction of the multilayer body;
• at least two of the plurality of the first through-holes are adjacent to each other and arranged along the first direction as viewed in the up-down direction of the multilayer body;
• a distance between centroids of the at least two of the plurality of first through-holes that are adjacent to each other and arranged along the first direction is uniform or substantially uniform as viewed in the up-down direction of the multilayer body;
• the plurality of the first through-holes include a first plurality of sets of first through-holes in the first spacer;
• the plurality of the first through-holes include a second plurality of sets of first through-holes arranged along the second direction;
• at least three of the plurality of the first through-holes are adjacent to each other and arranged along the second direction as viewed in the up-down direction of the multilayer body;
• a distance between centroids of the at least three of the plurality of first through-holes that are adjacent to each other and arranged along the second direction is uniform or substantially uniform as viewed in the up-down direction of the multilayer body;
• and
• at least one of the plurality of first through-holes is a first hollow through-hole overlapping the signal conductive layer as viewed in the up-down direction of the multilayer body.