Technology of welding sensor

As the core component of modern electronic equipment and automation system, sensor welding quality directly affects its performance and life. Welding a sensor refers to the process of connecting a sensor to its leads, electrodes or substrate. Different types of sensors require the use of different welding techniques to ensure stable transmission of electrical signals and reliable mechanical connections.

1. Type of welding sensor

There are a wide range of sensors, including temperature sensors, pressure sensors, accelerometers, humidity sensors and photoelectric sensors. Due to the different structure, materials and application environment of different sensors, the requirements for welding processes are also different:

Temperature sensors, such as thermocouples and RTDS, require welding materials with good high temperature tolerance and excellent electrical conductivity.
Pressure sensors: Metal film or ceramic materials are usually used, and the welding process needs to ensure tightness and mechanical strength.
Photoelectric sensors: Sophisticated microwelding techniques are often required to ensure that the welding points do not affect the function of the photoelectric element.

2. Common methods of sensor welding

The common technologies for welding sensors mainly include traditional tin welding, ultrasonic welding, laser welding and so on. Depending on the material and sensor type, selecting the right welding method can ensure the stability and reliability of the solder joint.

Tin welding: Commonly used in electronic sensors, especially small electronic components welding. By melting the solder, the pin of the sensor is connected to the circuit board, which has excellent electrical conductivity and relatively simple process.
Ultrasonic welding: Ultrasonic welding is suitable for welding metal film sensors or plastic substrate sensors, ultrasonic waves through the friction heat generated by mechanical vibration to bind the material without high temperature. The advantages are that it is suitable for heat sensitive materials, no pollution, and fast welding speed.
Laser welding: Laser welding is suitable for precision components and small sensors, the laser beam can accurately locate the welding point, and the energy is concentrated, suitable for high-precision welding of the sensor.

3. Precautions for sensor welding

In the process of welding sensors, there are several key elements that must be considered:

Welding temperature: Many sensor internal components are extremely sensitive to temperature, and the appropriate temperature must be selected when welding to avoid high temperature damage to the sensor function.
Solder selection: When welding sensors, lead-free, low-temperature, good conductivity solder should be selected to reduce the impact on the environment and improve welding quality.
Welding strength and tightness: For equipment such as pressure sensors, welding not only needs to ensure electrical connections, but also must provide sufficient mechanical strength and air tightness to prevent interference from external environmental factors (such as liquids and gases).