How the Unique Properties of Soluboard Can Steer Innovation for In-Mould Electronics

(Photograph: CCI Eurolam)

There are two types of plastic substances in the world – thermoset and thermoplastic. Thermoplastic materials can be reused and recycled, but thermosets will not break down as the chemical reaction which produced the plastic cannot be reversed.

The polymer used by Jiva in Soluboard is thermoplastic, differentiating the substrate from the thermoset epoxy-based market leading substrates such as FR-4. When fully cured under one application of heat and pressure, the epoxy in existing PCB laminates can no longer be changed.

Whilst Jiva has been predominantly targeting the rigid PCB market until this point, Soluboard is unique in that it can be heated to become flexible and moulded topographically before hardening upon cooling. This process can also be repeated due to the thermoplastic nature of the material.

Consumer products typically have an outer casing, commonly made from plastics, with rigid PCBs inside connected together with flexible PCB substrates. Not only is this an inefficient use of precious materials, it means that products are being engineered to allow for rigid PCBs to be placed within.

An increasing consumer desire for products with smaller form factors means that internal space is now a luxury, prompting the question ‘what if the product casing itself could also act as the PCB substrate?’

During recycling, the casing of a product has to be removed in order to recover the PCB which houses many precious metals. If the casing is produced from plastic, there is very little value in the material at end-of-life which means it is often sent to landfill. The dielectric nature of Soluboard combined with its thermoplastic properties could be a solution to this.

The Soluboard constituents can be combined into pellet form in order to act as a feedstock for existing injection moulding and overmoulding processes. This means that the raw materials can be engineered to produce mechanically sound, electrically insulating and fully biodegradable product casings which also contain the electronic components and circuitry traces.

Developments in the world of printed electronics which are compatible with Soluboard means that it is an ideal material to be introduced to the in-mould electronics (IME) market segment. In-mould electronics is the design principle of combining electronics with the product outer shell.

Described as the ideal synergy between form and function, IME is expected to decrease the weight of products by 70% with a 30% cost saving and a 40% saving in part assembly time (Source: DuPont). An IDTechEx Research report suggests that the IME market will surpass €215 million by 2024, with a large amount of innovation and interest from the automotive industry contributing towards this due to the growth of the Electric Vehicle industry.

A scenario can be imagined whereby Soluboard is used to produce the PCB for a computer mouse with an ergonomic contoured form factor for example. The Soluboard raw materials would then be overmoulded on top of the electronics using injection moulding in order to create a substrate-casing hybrid. This would further improve upon the existing plastic saving of Soluboard compared to FR-4 of 620 grams per square metre. The entire product would then be fully recyclable and soluble in hot water, enabling the recovery of the electronic components containing the precious metals and the repurpose or composting of the natural fibre structure.

Jiva is actively searching for partners to investigate how Soluboard can be integrated into the in-mould electronics market. Combining the reduced carbon footprint of Soluboard with the removal of plastic casings would drastically improve the green credentials of a product. If you believe you can contribute to our journey, please do not hesitate to reach out at [email protected].