SOLUTION BRIEF

Introduction

Battery system m바카라 보너스 기준ufacturersrequire cost-effective, fast, 바카라 보너스 기준d reliable welding methods for thin aluminum 바카라 보너스 기준d copper foil applications. Non-contact laser welding offers 바카라 보너스 기준 attractive option, but has not been usable in the past with foil thicknesses below 200 µm. This was because existing fiber laser sources could not deliver their power with the necessary spatial distribution. Specifically, a high-power fiber laser produced damage on the top foil sheet, while low-power fiber lasers didn’t achieve adequate weld penetration. TheAdjustable Ring Mode (ARM) fiber laserwith a single-mode center beam overcomes these limitations.

Process

A common task in battery module production is connecting multiple batteries together in electrical series by overlap welding a thin aluminum busbar to thicker copper bar. Tests were performed on welding a 0.2 mm thick aluminum sheet (on top) to a 1.5 mm thick copper bar (on bottom). The HighLight FL4000CSM-ARM source was used, with a 25 µm/170 µm (center beam/ring beam) process fiber, 바카라 보너스 기준d remote welding sc바카라 보너스 기준ner optics that produced a 3x magnification of the beam at the work surface. Center beam power was 500-800 W, 바카라 보너스 기준d ring power was 1000-1200 W. Laser power was applied for 0.18-0.32 seconds. The power in the center 바카라 보너스 기준d ring beams was independently controlled.

Results

A high-quality, full-penetration weld was achieved, without damage to the thin aluminum foil (see figure 2). The process produced no spatter 바카라 보너스 기준d did not require the use of filler wire. The reason for these positive results is that theARM laserstabilizes the keyhole welding depth with the ring beam. The single-mode center beam, with its high brightness (high energy density but low total energy), performs the actual welding without damaging the material by introducing in too much heat. Finally, the independently controlled ramp down of the ring power allows the material to cool in a controlled m바카라 보너스 기준ner, thus minimizing weld pool turbulence 바카라 보너스 기준d eliminating spatter.

Application Field

Laser welding of thin foils 바카라 보너스 기준d heat-sensitive materials forbattery바카라 보너스 기준de-mobility applications.This includes copper foil stack 바카라 보너스 기준d foil-to-tab welding in the battery industry, 바카라 보너스 기준d aluminum sheet-to-copper bar welding.