Board assembly, board, and electronic device

A board assembly comprising:

• a first board including a first signal line group including a plurality of signal lines extended in a first direction and lined up in a direction orthogonal to the first direction;
• a second board including a second signal line group including a plurality of signal lines extended in a second direction and lined up in a direction orthogonal to the second direction,
• wherein the first board and the second board are fixed such that the signal lines included in the first signal line group and the second signal line group are connected in line, and
• wherein the second board includes an additional signal line separated from the second signal line group in a thickness direction of the second board and extended across a second connection terminal group including a plurality of connection terminals connected to the second signal line group or the first signal line group;
• and
• an anisotropic conductive film containing a thermosetting resin between the first board and the second board,
• wherein the first board and the second board are fixed by being heated and pressed at a crimp section that includes the anisotropic conductive film, and
• wherein the second board includes at least one additional signal line at a position including the crimp section.

An electronic device comprising:

• a board assembly including:
• a first board including a first signal line group including a plurality of signal lines extended in a first direction and lined up in a direction orthogonal to the first direction, and
• a second board including a second signal line group including a plurality of signal lines extended in a second direction and lined up in a direction orthogonal to the second direction,
• wherein the first board and the second board are fixed such that the signal lines included in the first signal line group and the second signal line group are connected in line, and
• wherein the first board includes an additional signal line separated from the first signal line group in a thickness direction of the first board and extended across a first connection terminal group including a plurality of connection terminals connected to the first signal line group or the second signal line group.