Physical quantity sensor and inertial measurement unit

A physical quantity sensor comprising:

• three directions orthogonal to one another being defined as a first direction, a second direction, and a third direction;
• a substrate that is quadrangular-shaped, the substrate having first, second, third, and fourth sides, the first and third sides facing each other, the second and fourth sides facing each other;
• a first fixed electrode portion provided at a substrate, the first fixed electrode portion extending along the second direction, the first fixed electrode portion being fixed to the substrate via an electrode fixed portion, the electrode fixed portion being an end of the first fixed electrode portion;
• a movable body, the movable body being fixed to the substrate via a first body fixed portion, the movable body being configured with:
• a first movable electrode portion provided such that a movable electrode of the first movable electrode portion faces a fixed electrode of the first fixed electrode portion;
• a first support beam having one end coupled to the first body fixed portion;
• a second support beam having one end coupled to the first body fixed portion;
• and
• a first coupling portion coupling the other end of the first support beam and the other end of the second support beam to the first movable electrode portion, wherein
• when viewed in the third direction orthogonal to the substrate, the first movable electrode portion and the first body fixed portion are arranged along the first direction,
• the first support beam and the second support beam extend along the second direction,
• the first coupling portion includes:
• a first portion disposed along the second direction side by side with the first support beam and the second support beam;
• and
• a second portion coupled to the first portion and the first movable electrode portion and disposed along the first direction,
• an end part of the first fixed electrode portion having the electrode fixed portion extends toward the first side of the substrate along the second direction from any part of the movable body,
• the end part of the first fixed electrode portion is located closer to the first side of the substrate than the any part of the movable body,
• the first body fixed portion is located directly adjacent to the third side of the substrate without any structure intervening between the first body fixed portion and the third side of the substrate,
• when the movable body moves in the third direction or in a direction opposite to the third direction with respect to the substrate, the first movable electrode portion and the first fixed electrode portion detect a physical quantity,
• the first movable electrode portion includes a first base movable electrode, a first movable electrode extending from the first base movable electrode in the first direction, and a second movable electrode extending from the first base movable electrode in a direction opposite the first direction, and
• the first fixed electrode portion includes a first fixed electrode facing the first movable electrode and a second fixed electrode facing the second movable electrode.