TWI Knowledge Summary

The impact of environmental legislation on electronics and electrical product design and assembly

by Norman Stockham

Environmental legislation from around the globe is causing a total rethink of product design and manufacturing processes in a range of industrial sectors, including electronics, consumer products and automotive.

Traditionally, the manufacture of a product is a linear process, starting with manufacture and ending with disposal of the product when its useful life has expired.

This approach is resource-intensive, and leaves the problem of disposal of the product at the end of its life. Many such products are currently buried in landfill sites, but this activity is being strongly discouraged and 'take-back' legislation, such as the 'Waste Electrical and Electronic Equipment' legislation in the EU, requires that products are repossessed by the companies which manufactured them so that they can be recycled or disposed of appropriately.

The implication is that products will need to be designed with maintenance, refurbishment, re-use and recycling in mind. This is one aspect of a movement called 'sustainable development'. One possible view of future product manufacture and life-cycle management is shown in Fig 1.

Fig 1. Value curve for a typical consumer product showing the contribution of disassembly and recycling technology

The New technology indicated on the graph will include the means of disassembling some or all of the components, and the means of adding value to the components by sorting, testing, reusing, refurbishing and, if necessary, recycling the materials used to make components.

Product design

To accomplish the type of product life cycle envisaged in Fig.1, the design of the product must incorporate certain key features such as:

some facility to allow for upgrades or product evolution
the means of disassembling and inspecting the product thoroughly and in a cost-effective manner
the ability to disassemble and recycle as much of the product as possible.

This is a stringent set of criteria which suggests some degree of modularisation of component parts by function. In this way, product development and evolution can be handled one module at a time. Eventually, of course, a completely new product will probably be required and at this point the 'old' product will have to be refurbished or recycled.

In Japan, the concept of design for disassembly has been given a name, 'Inverse Manufacturing' ^[1] , and is being developed rapidly to minimise land-filling over a range of industrial sectors, such as automotive, electronics, textiles, building products, etc.

Material exclusions

A primary aim of the various elements of global environmental legislation is to minimise disposal of toxic materials in landfill sites. In the EU 'Restriction of Hazardous Substances' (RoHS) legislation, there are maximum limits for materials such as, lead, mercury, cadmium, hexavalent chromium, PBB and PBDE in electrical and electronic products. It is envisaged that the combination of legislation and rapidly increasing disposal costs will severely limit the use of many environmentally toxic materials in the next decade. An example of the implications of such material restrictions on an industrial sector is shown below for the PCB/solder assembly industry.

Impact on the soldering industry

The RoHS legislation, has had a major impact on all manufacturers using/producing solder systems, electronic components and PCBs, resulting in the following changes in production/assembly systems:

switch from the traditional tin/lead solder to lead-free solder
switch from tin/lead plating on PCBs to lead-free plating
switch from tin/lead plated components to lead-free plated components
modification of the soldering process, e.g. -

- higher temperature processing
management of all incoming parts in order to ensure and prove legislation compliance

General recommendations for manufacturing companies

Assess the relevance/impact of the approaching environmental legislation on your current products and assembly technology.
Wherever possible, avoid use of environmentally toxic materials. When their use is unavoidable, ensure that they are clearly marked and easy to separate.
Design new products for reuse, recycling and energy recovery.
Make products simple and inexpensive to take apart.
Where possible, always use the minimum number of different materials.
Consider the environmental legislation as a business opportunity.

Conclusions

Legislation is driving a change within manufacturing industry which will force companies to reassess the value-chain for products such that minimal or zero landfill is involved.

Joining, disassembly and recycling concepts will have to be developed before products embracing the 'zero-landfill' approach can be finally designed and manufactured.

TWI is in the process of developing certain key technologies and skills to help its Industrial Member companies meet the challenge of impending changes with the confidence to exploit the many opportunities which will be presented.

Reference

1 'Establishment of inverse manufacturing system technology', JETRO, March 1997.

Further information

Also, you can use the Weldasearch literature database to supplement what you find in JoinIT.