1. A circuit assembly comprising:a substrate with an electrically conducting path;
a plurality of plate-shaped busbars that each have a connection portion connected to the electrically conducting path of the substrate, and are arranged in an orientation in which plate surfaces of the plate-shaped busbars intersect with a surface of the substrate;
a heat discharge member that is laid on a side of the substrate opposite to the busbars, and is configured to discharge heat of the substrate; and
a resin frame that extends along the plurality of busbars, and holds the plurality of busbars while being in intimate contact with the plurality of busbars,
wherein the frame includes an outer frame portion that holds the busbars while being in intimate contact with the busbars, and an inner frame portion that is coupled to the inner side of the outer frame portion, and holds another busbar different from the busbars held by the outer frame portion while being in intimate contact with the other busbar, and
the outer frame portion includes a mounting portion mounted on at least either the substrate or the heat discharge member.