Equipment and method for preparing high-quality spherical welding powder

Abstract

Provided are equipment and method for preparing high-quality spherical welding powder. The equipment comprises a hopper-shaped atomizing tank (1), a supply device arranged on one side of the top of the atomizing tank, a rotary ultrasonic atomizing device (2) arranged in the center of the top of the atomizing tank, a cooling airflow disc (8) arranged in the atomizing tank and located on the lower portion of the ultrasonic atomizing device, an infrared radiation heater (21), a fluidifying sorting airflow disc (2), an atomizing area cooling device, a fluidifying sorting device, an ultrasonic screening machine (24) or a circulation tank (25). The infrared radiation heater (21) and the fluidifying sorting airflow disc (2) are located below the cooling airflow disc, the atomizing area cooling device and the fluidifying sorting device are arranged outside the atomizing tank, and the ultrasonic screening machine (24) or the circulation tank (25) are arranged at the bottom of the atomizing tank. The equipment is high in atomization efficiency and control precision and easy to operate, the prepared spherical welding powder is good in sphericity degree, the surface of the powder is smooth andfree of defects, and the crystal structure meets the high-quality requirement of tin cream.

Description

technical field [0001] The invention relates to the technical field of welding powder production equipment and production methods. Background technique [0002] Solder material is an indispensable connection material in the electronics industry. The application of surface mount technology (STM) with solder paste as the main connection material makes the electronic assembly process more efficient and miniaturized. SMT technology has become the mainstream of electronic assembly technology. Solder paste is mainly composed of solder powder and solder paste, of which the weight ratio of solder powder accounts for about 88-90%. Solder powder is one of the most important materials for preparing solder paste. [0003] At present, the methods of producing spherical solder powder include airflow atomization, centrifugal atomization and ultrasonic atomization. The solder powder produced by gas atomization has poor sphericity and more satellite spheres. The surface structure of centrifu...

AI Technical Summary

Problems solved by technology

[0003] At present, the methods of producing spherical solder powder include airflow atomization, centrifugal atomization and ultrasonic atomization. The solder powder produced by gas atomization has poor sphericity and more satellite spheres. The surface structure of centrifugal atomized tin powder is not easy to control the sphericity. The sphericity of tin powder is good, but the ordinary ultrasonic atomization process equipment adopts fixed-angle atomization, and the atomization vibration working area is small, resulting in low atomized metal flow rate and low atomization efficiency

Since the ultrasonic atomization device is designed in the atomization chamber, a sealed ultrasonic transducer cooling part needs to be designed separately, and the installation and maintenance are more complicated.

In addition, the atomization area needs to control the cooling rate of the alloy droplets. The usual atomization equipment adopts the water-cooled design of the atomization chamber jacket, which indirectly controls the temperature of the atomization area. The control accuracy is not high and uneven, and the temperature gradient is large. Major and other issues

In addition, during the spheroidization process of alloy droplets, it is necessary to control the low-oxygen atmosphere in the atomization area to adjust and control the surface tension of the droplets to achieve the spherical shape of the powder. Usually, the atomization chamber is first evacuated and flushed with nitrogen or Other inert gases, supplemented with air to achieve a low-oxygen atomizing atmosphere, have the problem of large and uneven oxygen concentration gradients

In addition, there is a certain amount of fine powder (<5um) in the atomized powder, which is difficult to sieve and remove with an ordinary ultrasonic sieving machine, and complex airflow classification is required

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