Because of its long cycle life, small size, light weight and no pollution, lithium batteries are widely used in mobile phones, notebook computers, electric vehicles, street lamp backup power supply, small household appliances, etc. In lithium battery, thermistor with negative temperature coefficient (NTC) is usually installed. NTC thermistor can prevent the battery from charging at too high or too low temperature, so as to avoid lithium battery overheating and cause accidents.
The use of SMT NTC thermistor has the advantages of high assembly density, small volume and light weight. The volume and weight of SMT NTC thermistor are only about 1 / 10 of that of plug-in thermistor. With SMD NTC thermistor, the volume and weight of electronic products can be reduced by 40% ~ 60% and 60% ~ 80% respectively. The chip NTC thermistor has high reliability, strong anti vibration ability, low solder joint defect rate, good high frequency characteristics, reducing electromagnetic and radio frequency interference, easy to realize automation and improve production efficiency. As a result, the cost can be reduced by 30% ~ 50% and materials, energy, equipment, manpower and time can be saved.
The use of NTC thermistor has the following advantages:
1. Save production and processing time. The traditional manual welding is simplified and the production time is shortened.
2. Avoid the contact displacement of plug-in NTC thermistor. If the contact of NTC thermistor moves to or around the heating device, the detection temperature of power management IC will deviate greatly.
3. Avoid short circuit. When NTC thermistor is damaged or exposed copper when it is supplied or processed, it is easy to short-circuit connect with some devices on PCB board, thus damaging PCB board or cell, and even causing safety accidents.
4. Avoid displacement and fracture, reduce the probability of human damage. The use of chip type NTC thermistor can effectively prevent NTC thermistor from breaking when it is supplied or processed, and prevent the temperature detection error of power management IC.