浅谈防水防潮温度传感器

Talking about waterproof and moisture-proof temperature sensor

Number of Views:41232022-02-15 09:05:18

NTC thermistors and NTC temperature sensors, which are composed of thermal chips as the core components and in different packaging forms, are widely used in various temperature detection, temperature compensation, and temperature control circuits. The core role of electronic signals. With the development of electronic technology, various electronic devices are further multi-functional and intelligent, and the application of thermal chips in various occasions such as temperature detection, control and compensation is increasing. Since the NTC temperature sensor needs to work in a humid environment, the requirements for waterproof and moisture-proof are getting higher and higher, so it is necessary to strengthen the package sealing and waterproof and moisture-proof performance of the NTC temperature sensor.

At present, the NTC temperature sensor includes a heat-sensitive chip arranged in a housing, and two sets of leads are arranged on the heat-sensitive chip. The leads are encapsulated with an epoxy encapsulating compound, and the epoxy encapsulating compound is encapsulated in the housing for curing the thermal-sensitive chip. The poor bonding between the temperature sensor encapsulation material and the lead leads to a loose structure. For example, in water or a high-humidity environment, moisture enters the gap between the lead and the encapsulation layer, and then gradually enters the thermal chip. When there is moisture in the core of the thermal chip , the resistance value will drop or be unstable, resulting in the temperature sensor not working properly and abnormal.

Therefore, a waterproof and moisture-proof temperature sensor has appeared, which has good waterproof and moisture-proof performance, stable resistance value without instability or sudden change, and has high mechanical strength.

The waterproof and moisture-proof temperature sensor includes a casing, at least one thermistor arranged in the casing, and connected to the electronic wire of the thermistor; the thermistor is encapsulated with a first encapsulation layer, which covers the thermistor and the thermistor and the thermistor. The connection point of the electronic wire; a potting layer is encapsulated between the casing and the thermistor; the tail of the electronic wire exposed to the casing is encapsulated with a second encapsulating layer, and the wire core of the electronic wire is exposed. The waterproof and moisture-proof temperature sensor is encapsulated with a second encapsulation layer at the tail to prevent moisture from entering the temperature sensor from the tail and prevent moisture from entering the temperature sensor. It has good waterproof and moisture-proof performance, and the temperature sensor has good resistance stability and high reliability.

The preparation method of the waterproof and moisture-proof temperature sensor comprises the following steps:

(1) Welding and connecting the thermistor and the electronic wire, then encapsulating the encapsulating material, wrapping and sealing the thermistor and the welding point, and sintering at high temperature;

(2) The encapsulated thermistor is placed in the housing, and the electronic wire is exposed, and the potting compound is injected or potted between the thermistor and the housing and sintered at high temperature;

(3) encapsulating the encapsulating material with the tail of the electronic wire exposed in the casing, exposing the wire core of the electronic wire, and sintering the encapsulating material at high temperature;

(4) The temperature sensor prepared in step (3) is placed in a pressure pump with oil, and the oil pressure of the breathing effect is carried out by means of circulating pressure and decompression, so that the oil can fully enter between the various gaps of the temperature sensor.

The waterproof and moisture-proof temperature sensor is encapsulated with a second encapsulation layer at the tail to prevent moisture from entering the temperature sensor from the tail; the temperature sensor is placed in a pressure pump with oil, and the breathing effect is carried out by circulating pressure and decompression. The oil pressure can make the oil fully enter between the various gaps of the temperature sensor, and isolate the water from entering the temperature sensor. It has good waterproof and moisture-proof performance, and the temperature sensor has good resistance stability and high reliability.

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