Thermal head and bonding connection method therefor

2 2A thermal head includes a head substrate having a common electrode and individual electrodes connected to exothermic bodies and a driving IC substrate having driving ICs controlling electrification of the individual electrodes and IC electrode pads arranged substantially in parallel with and at a smaller pitch (at most 60 μm) than the exothermic bodies. The individual electrodes and the corresponding IC electrode pads are bonded together with connection wire having a diameter of at most 23 μm. The connection wire includes a connection portion with a width larger than the wire diameter that is connected to the individual electrodes or the IC electrode pads and an upstanding portion raised from the connection portion at a predetermined angle. The surface area of the connection portion is not less than 0.0015 mmand the sectional area of the upstanding portion is not less than 0.00025 mm.