According to Wikipedia the world market for bare PCBs exceeded $60.2 billion in 2014 and in 2018, the Global Single Sided Printed Circuit Board Market Analysis Report estimated that the PCB market would reach $79 billion by 2024. At the same time the United Nations estimates that 40 million tons of e-waste are produced every year.
The traditional method of electronic product construction is the PCB — in essence, the permanent or semi-permanent attachment of electronic components or modules to thin metal tracks running over the surface of one or more layers of board. It is therefore productive to ask if this form of construction is the root cause of part of the mountain of electronic waste now causing a major world problem.
The Core Problem
The central problem which links PCB construction to electronic waste is that the permanent or semi-permanent soldering of components or sub-assemblies to a PCB makes repair, upgrade, disassembly or reuse difficult or impossible. Hence products are not repaired or upgraded and components and sub-assemblies are not disassembled or reused — they are simply chucked on the ever-growing and problematical waste mountain.
A further consideration relates to the Mean Time Before Failure (MTBF) and the Residual Value (RV) of the product or disassembled parts. Individual components have individual MTBFs, however the MTBF of a product often translates into the MTBF of the shortest-life component when the costs involved in skilled test and repair mean that it is uneconomic to diagnose faults.
The Direction of Travel
If we look at the bigger picture and see what has happened to the interconnection of individual electronic products we can start to see what may be on the horizon. In the not-so-distant past individual electronic products used to be connected by metal wires. CD players used to be connected by speaker wires. Computers used to be largely connected by network wiring systems. Disk drives used to be connected by means of multi-signal pathway BUS connections. Recently in all these examples the hard wire is being supplanted by new technologies centred on high speed serial connections — often over wireless or optical communications.
Technology is eroding the need for all the metal wires. Perhaps the same is about to happen inside the box.
We can envisage that all that may be necessary is that new components need to be supported on some form of modular frame replacing the support function of the traditional PCB. They can then discover each other and communicate by means of high speed serial wireless or optical communication.
Proposals
A review of these problems and trends indicates that the replacement of the custom designed PCB with a multi-purpose multi-product intelligent communications framework could substantially cut manufacturing costs and generate major society and consumer benefits:
- It is possible to design an intelligent two or three dimensional communications framework which would allow ICs, sub-assemblies and modules to be attached and then to identify each other and to configure themselves into a functional product. Software would sculpt the product.
- There would be major society and consumer benefits — it would:
- Facilitate the ability to upgrade, repair and re-designate use of electronic products
- Facilitate the ability to reuse functional electronic blocks into new products
- Provide an eco-friendly route to reduce the mountain of electronics waste
- Enable communication between ICs, sub-assemblies and modules internally and externally via high speed electrical, wireless or multi-spectral optical serial communication
INTERNATIONAL CONFERENCE ON CLEAN ELECTRONICS, Edinburgh, 9–11 Oct 1995, Conference Paper, 'A Novel Architecture to Facilitate Disassembly and Reuse of Electronic Components and Sub-Assemblies', Proced. 214–217, publ IEE & IEEE, co-author D.M. Holburn, D.S. Jordan, C.E. Hawkins (Cambridge University).