A dress made of circuits

MID technology manufacturing process

With Moulded Interconnect Device technology – MID for short – visible, three-dimensional conductive paths can be applied to the surface of injection-moulded components. This enables mechanical and electronic functions to be integrated on a single shaped part in a unique way.

The products can therefore be designed much more freely in terms of space and made much smaller and lighter – an important step towards further miniaturization. In addition, MID components often do not require any cables, which makes them much easier to mount. Unlike classic, primarily two-dimensional printed circuit boards, MID technology uses a three-dimensional shaped part as a circuit board, such as the housing for example. There are various ways to produce MIDs. In the case of the frequently used Laser Direct Structuring (LDS), a special metallic compound is added to the injection-moulding plastic. As a first step, this material is used to mould the required component.

Injection-moulded parts with structured conductive pattern

The areas that need to have conductive paths are then exposed with a laser beam. The additive is activated and immersed in a copper bath during the subsequent metallization process, which shows up the conductive paths in a sharp outline. Various coatings, for example nickel, gold, silver or soldering tin, can be applied one after the other. Electric circuits can be soldered onto these conductive areas.

Laser processing circuit boards and PCBS

Laser processing of circuit boards and printed circuit boards (photo credit: LPKF/LDS)

Photo credit: LPKF/LDS

BionicANTs – MID technology in miniature ant robots

For Festo, 3D-MID technology offers great potential for the future of automation technology and for use in future production systems. The BionicANTs are the first miniature robots that Festo has produced using this technology. This bionic technology platform is modelled on a real ant. It demonstrates how autonomous decision-making and cooperative behaviour facilitates efficient teamwork.

Thanks to 3D-MID technology, all the mechanical and electronic functions could be housed in the smallest of spaces on the ant, which measures just 13.5 cm, and precisely coordinated – function integration at its best!

MID in practice

The small-sized MID technology has already proven itself in many everyday applications. MIDs can for example be found in cars. A compact MID pressure sensor in the ESP brake control system converts the hydraulic braking pressure into an electrical signal. MIDs are also used in mobile telephones. The three-dimensional circuit boards on the plastic housing inside the mobile phone act as an integrated antenna. Applications can also be found in, among others, medical, air-conditioning and safety technology.