Infrared laser welding method for nonferrous metals

Abstract

The invention relates to an infrared laser welding method for nonferrous metals, and belongs to the technical field of laser machining and soldering. The infrared laser welding method comprises the steps that precise positioning is conducted through a visual alignment technology; electroplated pin feet on a connector are subjected to texturing pretreatment through lower-frequency laser; and then high-frequency laser is used for heating textured areas of the pin feet. The infrared laser welding method for the nonferrous metals has the characteristics of small reflection, local and rapid heating, rapid cooling and the like, and heat damage to the pin foot elements can be effectively lowered; and in addition, tin wicking can be avoided, and the welding percent of pass is greatly increased.

Description

technical field [0001] The invention relates to the technical field of laser processing soldering, in particular to an infrared laser welding method for non-ferrous metals. Background technique [0002] With the improvement of product design level and manufacturing technology in the electronics industry, laser soldering technology has been continuously developed and has been widely used in the electronics industry. In recent years, with the development of electronic products towards multi-function and miniaturization, the processing technology of PCBA (assembling various electronic devices on circuit boards through surface packaging technology) and the assembly density of electronic devices have been continuously improved. With the emergence of high-density and miniaturized electronic components with ultra-fine pin spacing, the size of interconnection solder joints is continuously reduced, and the reliability of interconnection solder joints is also required to be higher and...

AI Technical Summary

Problems solved by technology

When traditional wave soldering, infrared reflow soldering and other methods solder such fine-pitch pins, it is very easy to "bridge" the solder joints of adjacent pins, and it is difficult to achieve a stable yield rate.

Now there is also a processing method similar to laser soldering. The patent number is a laser soldering method of 200910189069. There is no obvious defect in processing PCBA insertion pins, welding wires and PCBA, but for PCBA and electroplating pins The laser soldering of the pins will cause unstable welding. Since the laser soldering adopts continuous or high repetition frequency laser welding, the electroplated pins are in close contact with the pre-tinned pads on the PCBA, and the electroplated pins are generally made of copper. Gold-plated parts and alloy nickel-plated parts are highly reflective to the above two lasers, and the pin foot absorbs laser energy unstable, resulting in inconsistent heat conduction to the pre-tin pad, which affects the welding yield.

Images