Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

High Quality and Process Stability for Welding Copper

19.04.2011
The Laser Zentrum Hannover e.V. (LZH) has developed a new process for micro-welding copper.

Using a short laser pre-pulse, the contacts are treated to provide 100 per cent good welds for the subsequent infrared welding.


Welded contacts on an IC (TSOP 0.5mm pitch) on a printed circuit board (Ilfa) using a laer pre-pulse and IR laser main pulse.

A newly developed "laser pre-pulse module" can be used to initiate the copper welding process and provide a 100% welding guarantee. The laser is small and inexpensive, the result of process developments at the Laser Zentrum Hannover e.V. (LZH). The pre-pulse is decisive for automating micro-processing, or for connecting surface mounted devices to printed circuit boards.

Copper alloys are often found in electronics, sensors and precision engineering applications. Here, high demands are placed on the heat and mechanical stress resistance of spot welds, and laser micro-welding has very good weld qualities. However, non-ferrous metals are difficult to weld, due to high reflectivity, and a sudden jump in energy absorption when the melting temperature is reached. It is difficult to repeat good welding results, and with low process stability, up to now lasers have only been used following complex surface treatment, or for manual applications.

Researchers at the Department of Production and System Technology at the LZH have developed a new process, which uses a laser pre-pulse with a peak output of no more than 1 MW and a pulse length of only a few nanoseconds to initiate the welding process. This short-pulsed, solid-state, frequency converted laser has a high degree of absorption, and provides stable conditions for the subssequent high-output welding using a conventional IR laser. The welding energy can be easily controlled after pre-pulsing.

Experiments using the pre-pulse prototype of the company neoLASE were carried out on an 80 µm thick, 2mm wide copper band. After 200 repetitions, the welding results were constant, implying that the welds were 100% good. "This result is already a great success," says engineer Anas Moalem, who is responsible for the development of the process. Apart from improved precision and quality, the process window for the laser parameters could be expanded considerably.

Depending on the weld spot diameter, the laser output power could be reduced by up to 40%, meaning that using the compact pre-pulse module (13 x 9 x 4 cm) could result in energy savings in the kilowatt range for the IR welding lasers.

Developments took place within the framework of the SME-innovation project "Supreme", which was financed by the BMBF (German Federal Ministry of Education and Research) under supervision of the PTKA-Project Management Agency Karlsruhe. Support was also given by the companies Arteos GmbH, Ilfa GmbH, neoLASE GmbH and Sill Optics GmbH & Co. KG.

Contact:
Laser Zentrum Hannover e.V.
Michael Botts
Hollerithallee 8
D-30419 Hannover
Germany
Tel.: +49 511 2788-151
Fax: +49 511 2788-100
E-Mail: m.botts@lzh.de
The Laser Zentrum Hannover e.V. (LZH) carries out research and development in the field of laser technology and is supported by the Ministry of Economic Affairs, Labour and Transport of the State of Lower Saxony (Niedersächsisches Ministerium für Wirtschaft, Arbeit und Verkehr).

Michael Botts | LZH
Further information:
http://www.lzh.de

Further reports about: LZH Stability Welding Distortion copper energy saving laser system welding process

More articles from Process Engineering:

nachricht Dresdner scientists print tomorrow’s world
08.02.2017 | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS

nachricht New technology for mass-production of complex molded composite components
23.01.2017 | Evonik Industries AG

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Microhotplates for a smart gas sensor

22.02.2017 | Power and Electrical Engineering

Scientists unlock ability to generate new sensory hair cells

22.02.2017 | Life Sciences

Prediction: More gas-giants will be found orbiting Sun-like stars

22.02.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>