03.22.2005

The House of Franck Muller draws on new technologies for the manufacture of certain micro-components of its complicated movements

The engineers of the Franck Muller Watchland R&D department, who are always attentive to the latest inventions in the sphere of micro-technology, followed the development of the photo-manufacturing technique[1] with interest. Given the amazing results that this method of manufacture offers as compared to traditional methods, they chose it for the production of certain micro-components of their complicated movements. Today, thanks to this revolutionary technique, the Franck Muller Watchland engineers have managed to produce parts of shapes and dimensions unimaginable until now.

The photo-manufacturing technique

This method of manufacturing micro-components consists in an association of photo-lithography and electro-forming.

The photo-lithography phase

A computerized drawing of the part is reproduced on a photo-mask in a layer of chromium engraved by an ultra-precise laser beam. The photo-mask is then laid on a substrate covered with a substance called photo-resist (a plastic which reacts to UV, from which comes the name photo-plastic). The photo-resist is irradiated with UV rays which solidify the photo-plastic and, after developing the non-irradiated photo-resist there remains a cavity which is the print of the part.

Electroforming phase

The material of which the part will be made is deposited by electrolysis in the imprint left in the photo-plastic. After the photo-plastic has been dissolved, the final part remains.

Principal advantages of photo-manufacturing

• This technique permits total freedom in the design of flat micro-components. It can be used to add decorations or inscriptions, it also allows for the production of skeletons and it is even possible to produce two-level parts.
• This technique guarantees better dimensional accuracy than does traditional machining.
• The part emerging from this technique does not require any finishing or heat treatment. As the part is made of a stainless material, it is not likely to rust and so does not need polishing. By using photo-manufacturing properly, assemblies can also be avoided.

A manufacturing method which meets the creativity and mechanical excellence requirements of the Franck Muller Watchland workshops

The parts used in Franck Muller great complications, made with the photo-manufacturing method according to instructions from the Franck Muller Watchland R&D department show the following characteristics. They are more precise and more perfect in form than micro-components made by a traditional method. They are also more resistant to wear and corrosion, they do not require any lubrication and they are non-magnetic.

[1] The photo-manufacturing technique was first developed by Dr. Hubert Lorenz as part of his doctorate at the Lausanne Institute of Technology.