In the manufacture of industrial applications, more and more industry sectors are turning to a new technology as an alternative to classic PCBs.

The revolution is called 3-D MID (Moulded Interconnect Devices or Mecha-tronic Integrated Devices) – injection-moulded plastic parts with conduc-tive traces integrated by using laser direct structuring (LDS).

This technique adds power to the trend towards miniaturisation in the electronics industry and provides product developers with new design op-portunities.

The projects from Multiple Dimensions, illustrates the diversity of possible ap-plications for 3D-MID. They simplify the operation of household appliances, improve driver experience in power steering systems and open new ways of saving space — for example in sensing and industrial electronics.

These fine, golden traces on formed plastic are transforming industrial produc-tion. The basis of all 3D-MID applications is a thermoplastic material: Using injection- moulding, first manufacture the part to fit the customer’s application, using different types of thermoplastic, which contain an additive that can be activated by laser.

A laser ray then engraves the surface of the plastic and activates the additive. A copper bath then follows, which lets the conductive traces form directly on the thermoplastic. Depending on the type of application, the MID parts may have to be extremely robust or temperature-resistant.

Some even must be acid or sweat-resistant, for example applications for hear-ing aids or headphones. In a final step, a barrier layer of nickel is applied and then conditioned with a thin layer of gold to ensure good solderability.

What differentiates the company from the competition is that it produces trac-es in almost microscopically small dimensions. Their manufacturing expertise can compete with anyone in the world, especially their uniquely fine trace width and the narrow spacing between traces.

Most suppliers are currently working with 300 – 400 µm spacing between trac-es. At Multiple Dimensions however the technological limit for trace width is 80 µm. These fine structures are now often used in Point of Sales (POS) terminals as a protection from hacking attacks. The fine traces allow attacks on the data in the payment cards to be detected.

From washing machines to steering wheels
It is the trace width and spacing between the traces that differentiates the top players in the new 3D-MID technology from the rest of the pack. It is the main factor affecting the degree of miniaturisation and it is decisive in terms of the number of functions that can be integrated in a component.

There are already many concrete examples of applications using the technolo-gy: They manufacture for a range of very diverse industries, such as rotary switches for programme selection in washing machines. These switches are normally made of a whole kit of small mechanical parts – with 3D-MID tech-nology none of these are now needed.

The washing programme is selected using a capacitive switch, i.e. virtually touch-free. This has far-reaching consequences: Unlike with a mechanical solu-tion, there is no friction to wear out the parts. The operator control device has a much simpler design, costs less to produce and on top of that, it has a longer service life.

The Swiss company manufactures sensors for the automotive industry which are used to measure the torque and position of steering wheels. Depending on the position and the measured value, the drive of the power steering is in-creased or decreased. The more accurate the measurement, then the more directly the vehicle response is felt.

Just like in the example of the washing-machine, the conventional solution con-tains numerous mechanical parts. When all these parts work together, devia-tions and tolerances cumulate and impair the driving experience. The company can eliminate an entire chain of tolerances.

The technology not only saves components and costs, it also makes the applica-tion more precise and efficient. And last but not least, it increases the user’s driving pleasure

A maximum amount of functionality in minimal space
Exceptional functional integration in a minimum of space is demonstrated by a solution currently produced by Multiple Dimensions for a toy manufacturer. For enhanced player experience, an electronic circuit has been built into a tiny space in a plastic component – including a battery, a capacitive switch and an LED.

There simply would not have been enough space there for a printed circuit board. Here too, the operating control device, in this case a capacitive switch, is totally wear-free, and there is no mechanical contact.

In future, the new 3D-MID technology will also be used in human-like robots. In Biel currently, experts from Multiple Dimensions are equipping the fingertips of a robotic hand (in the size of a human hand) with conductive traces.

The surface of the robot’s tactile organ is covered with sensors, their pressure signals are routed centrally to a connector. “Thanks to our 3D technology, we can place the required electronics accurately despite the complexity of working with a curved surface.

The trend towards miniaturisation growing in importance in everyday life
Customers of Multiple Dimensions benefit from the potential of the new tech-nology at many levels, including financially. They don’t just offer state-of-the-art methodology and expertise that is unique in the world today; they also de-liver it at a lower cost than many of our competitors.

All production steps are fully automated and performed in-house at Multiple Dimensions. They cover the complete process chain, from the injection-moulding process to laser processing and galvanisation, and even go as far as populating the electronic components. This saves transport costs and, most of all, time; savings that they are happy to pass on to customers.

The Managing Director of Multiple Dimensions is convinced that as far as the development potential of 3D-MID technology is concerned, the end of the road is still a long way off. “Advances in miniaturisation which are being made in all areas of our industrial society, combined with the trend to intelligent connect-ors for Industry 4.0, ensure that 3D-MID technology will be used even more widely in future.”