Laser soldering device and welding method based on fpc gold finger

Abstract

The invention discloses a laser tin soldering device based on an FPC (flexible printed circuit) golden finger. The laser tin soldering device comprises a first wavelength laser device, a second wavelength laser device and a controller, wherein the second wavelength laser device is different from the first wavelength laser device; the controller is used for controlling the first wavelength laser device and the second wavelength laser device to sequentially emit light; the first wavelength laser device is used for radiating a soldering area and preheating to reach the setting temperature, and then the second wavelength laser device is used for soldering and heating; in the soldering process, the first wavelength laser device is used for preheating a soldering area of the FPC golden finger to reach the preset temperature, the second wavelength laser device is used for soldering and heating the preheating area, and soldering tin is melted to connect a PCB (printed circuit board) and the golden finger. The laser soldering device has the advantages that the golden finger area is preheated by two types of laser with different wavelengths according to material properties, and the reflection of laser is reduced; when the setting temperature is reached, the second wavelength laser device is used for soldering and heating, and the soldering tin is melted to solder; the problem of part of material is destroyed while part of material just reaches the soldering temperature due to different temperature rise property in the soldering part of the PCB is avoided, and the soldering efficiency and soldering quality are improved.

Description

technical field [0001] The invention relates to the technical field of laser welding, in particular to an FPC gold finger laser soldering device and a welding method. Background technique [0002] FPC (Flexible Printed Circuit Board, flexible printed circuit board), has the advantages of free bending, folding, winding and so on. When assembling products, FPC can be arbitrarily arranged according to the layout of the product's internal space like wires, so that components can be arbitrarily arranged in three-dimensional space, so it is widely used in miniaturized electronic products, such as smart hands and tablet computers Wait. FPC mainly uses polyimide (PI) or polyester (PET) as the substrate on which copper clad laminate (FCCL) is used. There are two types of flexible copper clad laminate (FCCL) for FPC circuit boards, one is adhesive, and the other is One without glue, the one with glue is coated with glue on the PI film and then bonded with copper foil. There are two...

AI Technical Summary

Problems solved by technology

However, when the laser is used to weld parts composed of various materials, it is easy to cause uneven heating to damage some base materials or unstable solder joints.

That is, due to the particularity of the FPC base material, the gold finger area has a high reflectivity to the laser during laser welding, so it takes a long time to irradiate to ensure that the tin used as the solder melts, while the FPC base material in the gold finger area has a high reflectivity to the laser. The reflectivity of the laser is not high, increasing the laser irradiation time is also easy to cause the substrate to be damaged due to the increase in temperature

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