Estimated reading time: 1 minute

EPTE Newsletter: Monocoque Printed Circuits—An Update

Editor’s Note: Dominique Numakura first covered monocoque printed circuits in a column from May 2019.

What would you think if electronic circuits could be built directly on a polyethylene terephthalate (PET) package of strawberries and birthday cakes? It was a dream for electronics engineers to draw 3D circuits directly on the surface of the housing or packages of products. The idea behind molded interconnect device (MIDs) was created about 30 years ago to satisfy this dream. Several new processes, such as laser engraving and inkjet printing, have been proposed to build electronic circuits on 3D-structured objects. Unfortunately, no one was very successful with it as a popular circuit technology because of the technical and economic difficulties.

Wiring with flexible circuits could be a practical solution. Nowadays, most mobile device manufacturers are consuming huge amounts of thin, flexible circuits to attach on the surface of the housing in limited spaces. However, the cost of flexible circuits and assembling them is another headache for device manufacturers because they are not negligible in the whole cost of the devices.

Now, a new idea has been created in Taiwan to build 3D printed circuits. It looks like an egg of Columbus, and the manufacturing process is very simple. Firstly, a silver-based thick-film circuit is printed on a thermoplastic sheet, such as PET. The baking temperature of the circuit must be lower than the melting temperature. It depends on the capability of the circuit manufacturer, but double-layer circuits with via holes are available.

To read this entire column, which appeared in the September 2019 Flex007 section of Design007 Magazine, click here.