PCBA Tech - Explain the principle of laser filler PCBA welding

Explain the principle of laser filler PCBA welding
Laser filler PCBA welding refers to the method of pre-filling specific PCBA welding materials in the welding seam and then melting it with laser irradiation or filling PCBA welding materials while laser irradiation to form a PCBA welding joint.

Compared with non-wire-filled PCBA welding, laser-filled-wire PCBA welding has the following advantages: (1) It avoids the problem of too strict requirements for workpiece processing and assembly; (2) It can realize thicker and larger welding with smaller power PCBA (3) The structure and performance of the weld area can be controlled by changing the filler wire composition.

Test conditions and content

1 Test conditions

The test uses a YAG pulsed laser with an average power of 200W, the laser output mode is low-order mode, the focal length of the focusing lens is f=100mm, and it is protected by nitrogen.

2 Test content

The test piece is made of stainless steel wire with a diameter of Φ=1mm by a special method. Figure 1(a) shows one of them. What laser filler PCBA welding needs to do is to fill the missing wing of the opening and weld the PCBA, so that the cut wing is closed to form a gap, and the other wing can move in this gap. The gap is about 4mm long, and the two wings can be opened and closed easily after the PCBA welding place.

The total length of the test piece is about 4cm, the filler wire is stainless steel wire of the same brand, and the diameter is Φ=0.4mm. Using nitrogen as the shielding gas, the PCBA welding test piece is protected by the side axis nozzle.

When PCBA welding, use a special fixture to fix the PCBA welding test piece in the gas protection area, and use manual laser triggering and manual wire feeding for PCBA welding. Because the test piece is small, the test piece processed by the laser-filled PCBA welding process often has more fillers melted and accumulated at the PCBA welding position. Therefore, the PCBA welding position needs to be polished and trimmed to make the PCBA welding part and the surrounding structure form Smooth transition.

When PCBA welding, choose different PCBA welding process conditions (laser power, laser action time, focus position, wire filling angle, wire filling speed, etc.) to test the samples. iPCB is happy to be your business partner. Our business goal is to become the most professional prototyping PCB manufacturer in the world. With more than ten years of experience in this field, we are committed to meeting the needs of customers from different industries in terms of quality, delivery, cost-effectiveness and any other demanding requirements. As one of the most experienced PCB manufacturers and SMT assemblers in China, we are proud to be your best business partner and good friend in all aspects of your PCB needs. We strive to make your research and development work easy and worry-free.