Laser welding tested as a lead-free alternative

According to an article in Innovations Report, laser welding shows promise as an alternative for printed circuit boards. The goal of new research from the German research organization, Laser Zentrum Hannbover e.V. (LZH), is to weld electronics components for TVs, cell phones and computers using a two-laser solution. The procedure uses a green laser with low output power, followed by an infrared laser with higher output power to actually weld the components. The process is designed for optimal and repeatable process conditions. Since solder is not used, leaded materials are not necessary.

With the two-laser process, the component is first irradiated with a low-power green laser before the actual welding takes place. The radiation of the green laser is absorbed more easily, so the negative influence of irregularities on the component surface is minimized. Subsequently, the welding process with the infrared laser can take place under consistent conditions.

LZH claims the two-laser process produces high-quality welds. To support industrial implementation, LZH and other project partners are working on the development of the necessary laser sources, circuit boards and optics.