At present, most of the NTC thermistor products on the market are independent single components, the manufacturing process is usually the thermistor chips and leads put into the solder pot for welding processing, and then encapsulated and tested. NTC thermistor products prepared through this manufacturing process often lack the ability to protect against overvoltage. In the process of use, if encountering phenomenon of voltage leap or voltage flow backward, which is easy to damage and thus affect the normal operation of the circuit.
In order to overcome the shortcomings of the existing technology, EXSENSE Electronics introduce a resistance-composite NTC chip, this chip is a capacitor chip connected in parallel to a thermistor chip, thus effectively preventing voltage leap, which can absorb the overvoltage in the peak state and avoid the damage caused by the device in parallel with it. This new resistance-composite NTC chip includes NTC thermistor chip, capacitive chip, two leads, and a protective layer (glass protective layer). The thermistor chip is connected in parallel with the capacitor chip, and the two leads are set in parallel and connected to the both side electrodes of the thermistor chip, encapsulating the thermistor chip and the capacitor chip with protective layer. The manufacturing method includes the following steps:
First, according to the required resistance value to calculate the size, NTC thermistor chips are cut into the required size of the strips;
Second, according to the certain width to cut the capacitive chips into strips;
Third, the thermistor chips and capacitive chips which are cut into strips are be bonded;
Fourth, according to the required resistance value to calculate the size again, the bonded composite chips are cut into the required size of NTC chips;
Fifth, weld the two electrodes of the thermistor chip and capacitor chip of the NTC chip obtained in step four with the two parallel leads respectively, and the chip is inserted between the two leads. The thermistor chip and capacitive chip in the composite NTC chip are placed together in the solder pot, so that the composite NTC chip and the leads are connected with the welding;
Sixth, encapsulating the welded chip with a protective layer, which is encapsulated outside of the thermistor chip and the capacitive chip.
The resistance-composite NTC chip can effectively prevent chip damage or resistance leap by paralleling the capacitor chip on the thermistor chip. The high-accuracy NTC chip (accuracy can up to ±0.5%, ±1%, ±2%, ±3%) researched and produced by EXSENSE Electronic Technology Co., Ltd., which is small size, the minimum size can be 0.3*0.3mm, special specifications can be customized according to customer requirements.