A thermal fuse includes a first contact surface connected to a top surface of a sensor and a bottom surface connected to a bottom surface of the sensor. The sensor includes a mixture of Sn and Zn. The distance between the top surface and the bottom surface of the sensor is sized to substantially limit Zn depletion in a center region of the sensor when a temperature of the sensor is below a melting temperature of the sensor. The center region of the sensor prevents the first contact surface and the second contact surface from separating when the temperature of the sensor is below the melting temperature, and the first contact surface and the second contact surface are configured to separate when the temperature of the center region of the sensor exceeds the melting temperature of the sensor.