IIW White Paper

Portable power : In the Portable Power market, growth is being driven by high-drain wireless consumer devices. Primary portable power applications include consumer products, industrial and professional products, personal communication devices, portable computers, and military portable electronic devices. Rechargeable batteries and small engines will lead gains among established technologies. Solar cells are projected to remain niche items, while miniature and micro fuel cells become a major factor within this market by 2013. In the area of fuel cells, portable electric power is viewed as one of the earliest market applications. Much of the complexities related to hydrogen infrastructure are not an issue for portable electrical power applications, as is the case with many other fuel cell applications.

9.15 Microjoining sector

The involvement of microjoining in the electronics, instrument, actuator and sensors industries is as important and as extensive as that of welding in other manufacturing industries. The proper functioning of small mechanical devices and electronics systems, as employed in the aerospace, medical, telecommunications, computer, automotive, oil & gas and consumer industries, is critically dependent upon the use of efficient and reliable joining techniques. The increasing complexity and miniaturisation of micro and miniature devices are placing more stringent demands on assembly techniques for, and the performance of, microjoints.

Pressure sensor incorporating, laser, electron beam and thermosonic welding

The full range of welding, soldering and adhesive bonding techniques is being pushed to the limits to cope with increasing miniaturisation, process speeds and rapid changes in design. Additionally, the global drive to environmentally acceptable products is resulting in a review of assembly and disassembly techniques which is forcing a rethink in terms of the use of materials, joining and assembly processes. Although the term microjoining is widely used, it is difficult to define exactly. For the purpose of this review it is taken to include the joining of sheet and rod materials up to 1 mm in joint thickness.

Ball/wedge wire bonded die assembly

Welding is extensively used in microjoining applications such as silicon chip interconnect (e.g. wire bonding- thermosonic welding), package sealing (e.g. laser and resistance welding) and sensor/mechanical system assembly (e.g. EB, arc and resistance welding). There is the potential however to increase its use by exploiting its capabilities in terms of local/ low heat input, rapid processing capabilities and enabling more environmental assembly/design as illustrated.

Ultrasonic welded electrical terminations

Micro friction stir welded 0.5 mm thick Aluminium sheet

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Through Optimum Use and Innovation of Welding and Joining Technologies

Improving Global Quality of Life