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 Quick, Precise, but not Cold
17.05.2017 | Fraunhofer-Institut für Lasertechnik ILT

nachricht A laser for divers
03.05.2017 | Laser Zentrum Hannover e.V.

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

New photocatalyst speeds up the conversion of carbon dioxide into chemical resources

29.05.2017 | Life Sciences

NASA's SDO sees partial eclipse in space

29.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>