Joining processes in the automotive industry using high-power laser diodes

• Research unit: EU RFP
• Project number: 96.0341

Key words (English)

Joining; brazing; preactivation; soldering; high power laser diodes; focusing optics; process control; heat transfer interaction mechanism

Alternative project number (English)

EU project number: BRPR-CT97-0419

Research programs (English)

EU-programme: 4. Frame Research Programme - 2.1 Industrial and materials technologies

Short description (English)

See abstract

Partners and International Organizations (English)

Centro Ricerche Fiat CRF, Orbassano (I), Thomson-CSF LD, Paris (F), R.Bosch GmbH, Schwieberdingen (D), Daimler, Sindelfingen (D), Institut für Strahlwerkzeuge IFSW, Stuttgart (D), Centro Laser, Bari (I)

Abstract (English)

The project addressed two important joining procedures in the automotive industry by using high power laser diodes. The first process is the pre-activation of adhesives for joining different car body materials such as zinc-coated steel, aluminium, and composites. The second process envisaged in the project, using the same laser technology, is soldering and brazing of electrical contacts in cars, where reliability demands are extremely high, under conditions which are demanding mechanically and concerning temperature changes. Soldering using high power laser diodes is expected to meet quality and automation requirements as well as economical restrictions. Soldering as well as adhesive preactivation require a laser source which is cheap and reliable, while intensity demands are not too strong.
The project has been successfully finalized with major achievements for the different partners. The power available with the final diode laser prototype (260 W) and with very tight focusing (ø< 0.8 mm) is an ideal basis for product development on one side and for industrial investigations in different applications on the other side. FISBA OPTIK AG integrated a new micro-optical collimation scheme based on the idea of higher power available at higher integration of the laser diode bars. With the application of this project oriented to joining technology, the rapid industrial reaction of the project partners has to be emphasized with different applications which have been transferred to an industrial process already. The application of adhesive pre-activation with high power diode laser bears however no commercially attractive potential and is therefore not exploitable for industrialization within the near future. The emerging applications of selective soldering and plastics welding and the increasing acceptance of the diode laser as an automated tool in the automotive industry gives rise to the best expectations for the future developments.

References in databases (English)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 96.0341