China’s total raw coal production accounted for 59.31% of the global coal production ranking in 2021, about 4.071 billion tons. Therefore, the number of coal mines in our country is too numerous to list. In order to ensure the safety of the lives and properties of coal miners, China’s coal mines are basically equipped with gas monitoring systems. Compared with traditional catalytic detector, a more mature monitoring system is being gradually introduced. It uses the laser emitted by the laser to measure the concentration of the gas and obtain relevant data information. In order to keep the laser operating normally in the constant operating temperature range, the NTC thermistor chip is generally added as a component of temperature control.
Although laser has various advantages, temperature has a greater impact on the performance and performance of laser. As:
First, the temperature will affect the output wavelength of the laser. When the current is constant, for every 1°C increase in temperature, the wavelength of the laser increases by about 0.1nm;
Second, the temperature will affect the output power of the laser. Temperature changes will cause the relationship between power and current to be nonlinear.
Third, the temperature will affect the life of the laser. A sharp change in temperature can affect the output power of the laser, affecting its lifetime.
Therefore, in the use of laser, TEC and NTC thermistor chip are generally linked to jointly control the temperature of the laser. In order to better ensure the work of the laser, the following requirements are also put forward for thermistor chip:
First, high accuracy, which can ensure that the laser works at a temperature closest to 25℃;
Second, high reliability, which can ensure that the laser has maintained high-precision performance in a long period of work;
Third, small size , this requirement is reflected in two aspects: now the device integration is getting higher and higher, and the small size of the NTC thermistor chip can be more space-saving when integrated in the laser module; The reaction speed is fast, the role of the thermistor chip is to help the laser constant at the operating temperature, its reaction speed must be fast enough, so as to assist TEC to perform heating/cooling work, otherwise it will cause the laser operating temperature to shift too much.
Fourth, suitable for the gold wire bonding process, the connection process of each component in the conventional laser is gold wire bonding process.
DT series gold electrode NTC thermal chip of EXSENSE Electronics Technology Co., Ltd. can be applied to laser, which is characterized by high accuracy (2%, 1%, 0.5% can be selected), high reliability (reliability rate of change <0.6%), high sensitivity. Its electrode material is gold electrode, which is suitable for gold wire bonding process. In order to cooperate with customers, it can also be used for silver glue (paste) curing process and eutectic bonding process.
