Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

LIMBO: Innovative joining technology for temperature-sensitive components

04.11.2015

This November, the Experts of the Fraunhofer Institute for Laser Technology ILT will be presentinga pioneering novelty at productronica 2015, the world's leading trade fair for electronics development and production.They are focusing on a totally new laser-based joining technique that will provide plenty of momentum to the electronics production industry.

The five letters stand for a development from Aachen that is meant to inspire specialists from the electronics manufacturing sector: they are talking about another kind of “LIMBO,” the acronym for “Laser Impulse Metal Bonding.”


A 200 µm thick copper ribbon on a PCB joined via the LIMBO process.

© Fraunhofer ILT, Aachen, Germany.


Cross-section of a LIMBO joint between a 200 µm copper interconnector and a printed circuit board.

© Fraunhofer ILT, Aachen, Germany.

“This laser process expands the process limits of conventional welding and soldering processes considerably," explains Dipl.-Ing. Simon Britten, head of the LIMBO project.

“It opens up completely new fields of applications for the joining of temperature-sensitive components.” Within three years, the researchers have developed a thermal joining process that overcomes the limitations of conventional methods and deposits only a minimum of energy in the components.

This enables the unprecedented joining of components such as thick ribbon interconnectors in power electronics with sensitive, fast-switching chips (e.g. for wind turbines or electric vehicles). In contrast to soldering, the contacts have a high temperature stability and show, in comparison to conventional welding or bonding, a minimal effect on the component.

Joined cool

“Thanks to LIMBO, we can now also thermally join thick ribbons that have a thickness of 200 µm or more with thin metallization layers,” says the expert on micro joining. “The secret is in breaking up the classical welding process into the separate phases of heating and joining.”

In contrast to typical electrical connecting processes, here a relatively large gap is used, in which a thermally isolated weld pool forms. Britten: “We control the process – which lasts a total of less than 20 milliseconds – so that the connection is essentially made solely by the energy in the melt, and not by the laser beam. This leads to a minimal energy input.”

In a process where embossment or isolation material is used to create gaps of more than 50 µm, the LIMBO process can be applied when the metallization layer has a thickness in a two-digit micrometer range. At productronica, Fraunhofer ILT will demonstrate the process using a fiber laser (wavelength: 1070 nm).

“All laser sources that can be modulated in the range of milliseconds to microseconds can be used,” explains the scientist. “What is needed for the short exposure time is a laser power of about two kilowatts, but with the fiber laser around 500 watts are also sufficient.”

Experts will be showing possible applications of LIMBO at the productronica

Now that Fraunhofer ILT has laid the basic groundwork, the project manager and his team are certain how LIMBO works and that it is reliable. “This process can be considered – thanks to its low penetration depth of less than 20 microns – for many applications with heat-sensitive components,” says Britten.

The range of possible applications for LIMBO is very broad: it extends from inserts in control technology for alternative energy (keyword: power electronics for inverters of wind turbines) to electro mobility.

“We are helping prospective customers adapt the process to their applications by means of functional models.” Interested parties can find out more about LIMBO and its potential applications at the productronica in Munich from November 10 to 13 at the Fraunhofer Joint Booth 2017 in Hall B3.

Contact

Dipl.-Ing. Simon Britten
Micro Joining Group
Telephone +49 241 8906-322
simon.britten@ilt.fraunhofer.de

Dr. Alexander Olowinsky
Head of the Micro Joining Group
Telephone +49 241 8906-491
alexander.olowinsky@ilt.fraunhofer.de

Fraunhofer Institute for Laser Technology ILT
Steinbachstraße 15
52047Aachen, Germany

Weitere Informationen:

http://www.ilt.fraunhofer.de

Petra Nolis | Fraunhofer-Institut für Lasertechnik ILT

More articles from Process Engineering:

nachricht New manufacturing process for SiC power devices opens market to more competition
14.09.2017 | North Carolina State University

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

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Antarctic landscape insights keep ice loss forecasts on the radar

20.11.2017 | Earth Sciences

Filling the gap: High-latitude volcanic eruptions also have global impact

20.11.2017 | Earth Sciences

Water world

20.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>