Selecting the attachment technique that is used to assemble and disassemble your electrical and electronic products requires careful consideration.
The choice of attachment type is likely to depend on assembly cost and required performance parameters during the product's lifetime. For example, you'll need to decide whether the attachment is permanent during the product's lifetime or if it needs to be reversible for servicing, repair or upgrade. Your choice will affect the purity of recycled materials and hence their value. Reversible attachments need to be accessible, easy to remove and durable, and will give purer materials after disassembly.
Where fasteners are used, you should consider:
- making fastening points accessible, visible and clearly marked
- using a simple component orientation
- using screws in place of rivets for easier disassembly at the end of the product's life
- standardising screw heads to aid assembly and disassembly
- avoiding assemblies that require power tools
- using fasteners of the same material as the parts to be joined to optimise recycling opportunities at the end of the product's life
You can design snap-fits to allow rapid and efficient disassembly of the product, eg by ensuring that the tines are easily accessible. However, in some cases they may not provide adequate pressure on connecting parts, for example to ensure adequate conductive continuity in products requiring shielding from electromagnetic interference, and in areas with high levels of vibration.
You should avoid joining dissimilar materials using adhesives or welding. Staking techniques for joining thermoplastic parts to other materials can provide a low-cost approach, but reduce opportunities for end-of-life materials and component recycling.