Fastener assembly is one of the most important joining processes in manufacturing, including in the 3C industry (computers, communications, and consumer electronics). Many smartphone components and assemblies, such as multi-layer boards (MLBs), vibration motors, antenna modules and camera modules, are joined with fasteners in a process that is usually automated. A variety of threaded fasteners are used, including micro fasteners in sizes ranging from M0.8 to M2.
In the 3C industry, the demands in terms of assembly speed and quality are extremely rigorous. End-to-end quality monitoring is required for micro-fasteners, fastening tools, and bolted joints. Standard-compliant testing of threaded fasteners in accordance with ISO 16047 – from product development to production – is a recognized method of ensuring and demonstrating their quality. However, this standard only covers testing for threaded fasteners of size M3 or larger. This means that, at the moment, there are no standardized torque and clamp force tests for the micro-fasteners used in the 3C electronics industry.
Manufacturers are left to use their own testing methods based on a reduced number of control parameters, often only specifying the fasteners’ breaking torque. The risk of faulty design, complaints, recalls, and the costs incurred as a result is therefore great and practically unavoidable.