A sensor includes a diaphragm having a bonding portion and a main boss separated from the bonding portion by at least one channel, the main boss having a first side face, a second side face and a chamfered corner face connecting the first side face to the second side face. A base of the sensor has a first contact area aligned with the main boss and separated from the main boss, wherein the bonding portion of the diaphragm is bonded to the base. At least one sensing element senses movement of the diaphragm.