Laser welding tinning device and welding method

Abstract

The invention designs a laser welding tinning device and a welding method. The tinning device comprises a back plate, a laser position correcting device, a camera, a laser machining head, a pushing wheel pair, a connecting rod, a tin feeding nozzle, a displacement sensor, an angle sensor, a balance spring, a controller and a residue box, wherein the angle sensor detects a swing angle of the connecting rod, the displacement sensor detects the vertical movement position of the connecting rod, the controller calculates the movement speed and the acceleration of the detection head according to thedisplacement amount and an angle change value of the detection head, during laser welding, laser working height closed-loop control is carried out by utilizing the position of the detection head, tinwire feeding speed closed-loop control is carried out by utilizing stress of the detection head, and closed-loop control that laser follows the position of a tin wire is carried out by utilizing theangle of the detection head, influence of the welding spot height difference on the welding effect can be made up, the product machining fixing requirement is lowered, and the application range of laser welding is expanded. The tinning device is advantaged in that mechanical collision or burning of a processing base material can be prevented, the process is stable, and the qualified rate is improved.

Description

technical field [0001] The invention relates to a tinning device for laser welding and a welding method, in particular to a tinning device for laser tin wire welding and a welding method using the device, belonging to the technical field of laser tin wire welding. Background technique [0002] In the field of fine processing of laser tin wire welding, as the requirements of production technology become higher and higher, the conditions of use of processing equipment are becoming more and more stringent. Existing traditional equipment often cannot meet the requirements of emerging technologies. For example, when laser welding specific tiny solder joints, a slight deviation between the laser and the tin wire or the solder joints will cause the solder joints to burn or the substrate to be scrapped. The difference between laser soldering and traditional electric soldering iron welding is that there is no contact force directly acting on the solder joint during laser welding. If ...

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Problems solved by technology

[0003] The Chinese utility model patent "Laser soldering device for automatic calibration and tin feeding" (201820105083.4) uses a laser emitter and the first CCD component, etc., which are used to melt the tin wire for welding and obtain the image information of the tin wire; and then obtain the image information of the tin wire The protruding length, the deviation between the tin wire and the laser spot, and the appearance information of the tin wire; then use the control laser emitter and the tin feeding component to trim the tin wire to solve the problem of tin feeding amount control and automatic correction. The problem is that the device cannot accurately determine the contact force between the tin wire and the solder joint; the Chinese invention patent "A Tin Wire Precision Welding Device and Control Method" (201710413205.6) is based on two sets of vision systems that collect three-dimensional images of tin wire. By comparing the length, position and attitude of the tin wire at the initial and detection times and obtaining the deviation, and then using the laser tin cutting process, automatic tin scraping process and automatic tin wire pushing method, the solder ball, bending, and deformation at the top of the tin wire can be solved , length error accumulation, there is also the problem that the contact force between the tin wire and the solder joint cannot be accurately judged; the Chinese invention patent "An automatic tin wire feeding device for laser welding" (201811475586.1) only solves the problem of ensuring the wire feeding mechanism when the deflection angle The position of the wire is always consistent with the laser soldering point, avoiding stress and deformation of the tin wire during wire feeding, and preventing problems caused by wire jamming

[0004] In the prior art or published patents, the visual system is mainly used to correct the processing position or dynamically adjust the process. The devices or methods used cannot accurately judge the contact force between the tin wire and the solder joint, let alone adjust the device in real time according to the contact force. On the other hand, when laser welding pin devices, the inclination direction of the solder joint pins is a random amount. If tin wires are sent to a batch of pins (or pins) in a fixed posture, the tin wires will May be bent or deflected by some pins, resulting in improper soldering

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