idw – Informationsdienst Wissenschaft

Nachrichten, Termine, Experten

Grafik: idw-Logo
Science Video Project
idw-Abo

idw-News App:

AppStore

Google Play Store



Instance:
Share on: 
10/29/2009 10:33

High Speed Laser Soldering for Flexible Interconnection of Self-Bonding Copper Wires

Dipl.-Phys. Axel Bauer Marketing und Kommunikation
Fraunhofer-Institut für Lasertechnik ILT

    For manufacturing processes with small and medium quantities in the sectors of electrical, medical and sensor engineering, the Fraunhofer Institute for Laser Technology ILT has established an automated laser soldering process that significantly increases the flexibility as well as the process speed of production. In view of the progressing miniaturization of building groups, this process has great potential.

    Manufacturing highly integrated, electro-engineering components in Europe primarily demands, in addition to high quality, a high amount of flexibility to remain competitive against the cost advantages found in low-wage countries. Manufacturing facilities have to be transferable to a wide variety of products, preferably without retooling. In addition, quick, highly automated manufacturing procedures are necessary for largely unmanned manufacturing. Exposed to these requirements are small and medium-sized enterprises who occupy market segments for highly integrated electrical engineering components in small and medium quantities; such segments cannot be served by mass production facilities. Examples are innovative products from medical or sensor technology for which a significant production step is the interconnection of enamel-insulated coil wires to connection pads on a circuit board.

    Currently, the interconnection is soldered manually for these products due to a lack of automation facilities. Since the process and the geometry of the component are complicated, the manufacturing process can only be reproduced with difficulty. The quality of the solder connection, thus, strongly depends upon the person conducting it. So that the insulating enamel layer is removed from the wire, the hot soldering iron has to be guided over the individual wire several times with a certain contact pressure - this way the insulating enamel melts and the bare wire surface contacts the liquid solder immediately. This method is not only time consuming, but also harbors a danger: the section of wire to be connected can tear when very thin self-bonding wires, e.g. < 100 µm, are used, or a sound electrical interconnection cannot be established. As an alternative, the stripping of the wire can be conducted chemically or mechanically. Both processes are, however, insufficient - they contain complex process chains and cannot be applied if the subassemblies are miniaturized or if an absolutely necessary process, enamel removal of the wire (e.g. for stripping directly on the subassembly), is integrated into the joining process.

    To increase the process speed and reproducibility, the Fraunhofer ILT has developed an automated laser soldering process that not only enhances the manufacturing flexibility, but also offers great potential for further miniaturization. With this process, the enamel removal and the interconnection take place in one single process step. On the one hand, the reproducibility is significantly increased via integrated process monitoring and control based on pyrometric sensors used in the laser-beam soldering process. On the other, the contactless laser soldering process offers significant potential for miniaturization in comparison to competing processes, since the dimensions of the connecting pads can be reduced down to several hundred micrometers.
    This automated soldering process allows not only a nearly free choice of connection geometries, but also makes manufacturing so flexible that any number of quantities - even individual parts - can be produced without increasing reaction time, as a particular product requires. Medium-sized companies in the sector of electronic manufacturing can clearly fall back on the expertise of the Fraunhofer ILT.

    Contact Partners at Fraunhofer ILT
    Our experts would be glad to answer any questions you may have:

    Dipl.-Ing. Felix Schmitt
    Department of Microtechnology
    Telephone +49 241 8906-322
    felix.schmitt@ilt.fraunhofer.de

    Dr. Arnold Gillner
    Head, Department of Microtechnology
    Telephone +49 241 8906-148
    arnold.gillner@ilt.fraunhofer.de

    Fraunhofer Institute for Laser Technology ILT
    Steinbachstraße 15
    52074 Aachen
    Germany
    Tel. +49 241 8906-0
    Fax. +49 241 8906-121
    http://www.ilt.fraunhofer.de


    More information:

    http://www.ilt.fraunhofer.de/eng/100000.html


    Images

    Demonstrator component to solder self-bonding wires on circuit boards.
    Demonstrator component to solder self-bonding wires on circuit boards.
    Source: Source: Fraunhofer ILT.


    Criteria of this press release:
    Electrical engineering, Physics / astronomy
    transregional, national
    Research results, Transfer of Science or Research
    English


     

    Demonstrator component to solder self-bonding wires on circuit boards.


    For download

    x

    Help

    Search / advanced search of the idw archives
    Combination of search terms

    You can combine search terms with and, or and/or not, e.g. Philo not logy.

    Brackets

    You can use brackets to separate combinations from each other, e.g. (Philo not logy) or (Psycho and logy).

    Phrases

    Coherent groups of words will be located as complete phrases if you put them into quotation marks, e.g. “Federal Republic of Germany”.

    Selection criteria

    You can also use the advanced search without entering search terms. It will then follow the criteria you have selected (e.g. country or subject area).

    If you have not selected any criteria in a given category, the entire category will be searched (e.g. all subject areas or all countries).