IIW White Paper

The electronic products industry sector includes both consumer electronics and electronic devices that are incorporated into other components, including medical devices, aerospace, automotive, and defence products. The market is divided into applications such as consumer, communications, computer, industrial, and automotive. The world electronic product market was $1.8 trillion in 2006 and was expected to increase at a compound annual growth rate of 9.5% over the next five years. Industrial products accounted for 39.6% of the sales in this market, and consumer electronics made up 13.4%. Industry reports break down the consumer electronics market into four categories, computer, personal communications, home media devices, and luxury devices. In a 2005 industry report published by In-Stat the top three devices in terms of growth were portable digital audio players (57%), LCD televisions (52.3%), and DVD recorders (51.4%).

Rapid advances in computer and associated electronic systems can only be sustained by advances in joining methods adapted to a miniature scale of operation. There are six basic joining operations in the assembly of electronic products: package fabrication, attachment and interconnection of active and passive components, package sealing, package attachment and other devices to PCBs and the mounting of electronics in a fabricated enclosure. The joining techniques commonly used for these operations are shown below.

Thermosonic wire bonded silicon chip

Welding is fundamental to the assembly and performance of electronic devices. For example, 25 µm- diameter wire welds (thermosonic/ultrasonic) are used to interconnect silicon chips per year in excess of 5 trillion. In harsh environments (e.g. medical implants, chemically active or high temperature) the quality of the package sealing weld (e.g. laser, electron beam) can directly influences the electronic device reliability and life.

Table 9.1 Joining processes used in the electronics sector

Activity Joining process

Metal/ceramic package fabrication

Brazing, Soldering, Resistance welding Laser, electron beam and arc welding, Glass fusion Soldering Adhesive bonding Thermosonic/Ultrasonic hot pressure welding Soldering Plastic encapsulation, Glass fusion Resistance brazing, Resistance, laser and EB welding Cold pressure welding, Soldering, Adhesive bonding Soldering, Adhesive bonding Resistance welding Mechanical fastenings, Adhesives, Plastic and metal welding

Attachment of active or passive components to substrate circuitry Interconnections to solid state circuits

Package sealing

Attachment of packaged and other devices to circuit boards Fabricated enclosure

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Through Optimum Use and Innovation of Welding and Joining Technologies

Improving Global Quality of Life