Multilayer substrate connecting body and transmission line device

A multilayer substrate connecting body comprising:

• a first multilayer substrate that includes:
• a plurality of first insulating base material layers that are stacked on one another;
• and
• a first conductor pattern provided on each of at least two of the plurality of first insulating base material layers;
• a second multilayer substrate that includes:
• a plurality of second insulating base material layers that are stacked on one another;
• and
• a second conductor pattern provided on each of at least two of the plurality of second insulating base material layers;
• and
• an anisotropic conductive film;
• wherein
• each of the first multilayer substrate and the second multilayer substrate includes a step portion that is provided due to a difference of a number of stacked layers of the plurality of first and second insulating base material layers and exposes a portion of a plurality of the first and the second conductor patterns;
• the plurality of first conductor patterns that are exposed to the step portion of the first multilayer substrate are disposed at respective different positions in a stacking direction in which the plurality of first insulating base material layers are stacked;
• the plurality of second conductor patterns that are exposed to the step portion of the second multilayer substrate disposed at respective different positions in the stacking direction;
• the anisotropic conductive film is disposed between the step portion of the first multilayer substrate and the step portion of the second multilayer substrate, and causes portions of the plurality of first and second conductor patterns that are respectively exposed to the step portion of the first multilayer substrate and the step portion of the second multilayer substrate to be electrically connected to each other at a plurality of positions of the anisotropic conductive film;
• the step portion of at least one of the first and second multilayer substrates includes a plurality of steps;
• the anisotropic conductive film includes a single anisotropic conductive film that covers the plurality of steps of the step portion of the at least one of the first and second multilayer substrates;
• a distance in the stacking direction between the step portion of the first multilayer substrate and the step portion of the second multilayer substrate is constant or substantially constant;
• and
• a resist film is provided on a portion of at least one of the first conductor pattern and the second conductor pattern.