Sensor fixing structure, wearable device, and hot melt apparatus

A sensor fixing structure, comprising:

• a bracket on which a connecting arm is projectingly provided, wherein the connecting arm is a hot melt stake;
• and
• a sensor structure covered by the bracket, wherein the connecting arm comprises a connecting section and a holding section, one end of the connecting section is connected to the bracket, the other end of the connecting section is connected to the holding section, the holding section is located at a side of the sensor structure that faces away from the bracket, and hold the sensor structure to the bracket, and the connecting arm forms the holding section by hot melt processing,
• the sensor structure is an infrared sensor structure, and infrared rays emitted by the infrared sensor structure can pass through the bracket and exit,
• wherein the sensor structure comprises a circuit board assembly and an infrared sensor mounted on and electrically connected to the circuit board assembly;
• the bracket comprises a mounting portion and a penetration portion, the holding section holds a side of the circuit board assembly that is away from the infrared sensor, and the infrared sensor is held to the penetration portion.