Patent ID: 9536828
Date: 2017-01-03
CPC Classifications: H01L

Claim:
1. A semiconductor device comprising: a semiconductor substrate; a first coil, a second coil, a third coil, a fourth coil, a first pad, a second pad, and a third pad formed on the semiconductor substrate through an insulation film; and a lead wiring for connecting the first coil and the third coil to the third pad, the lead wiring extending from a portion between the first coil and the third coil to the third pad, and a width of the lead wiring being greater than a wiring width of the first coil and the third coil, wherein the first coil and the third coil are electrically connected in series between the first pad and the second pad, the third pad is electrically connected between the first coil and the third coil, the second coil and the fourth coil are electrically connected in series, the first coil is arranged above the second coil, the third coil is arranged above the fourth coil, the first coil and the second coil are not connected by a conductor but are magnetically coupled to each other, the third coil and the fourth coil are not connected by a conductor but are magnetically coupled to each other, and, when a current is flowed in the second coil and the fourth coil connected in series, directions of induction currents flowing in the first coil and the third coil are opposed to each other in the first coil and the third coil.