Few materials are ductile, electrically or thermally conductive, or have the shiny appearance of metals. Yet there are a growing number of fields (plastronics, packaging, intelligent textiles, cosmetics) where these specific properties are required on all or part of the surface of certain devices. Selective surface metallization makes it possible to reconcile these a priori antagonistic objectives. It consists of a set of techniques (mechanical, physical and/or chemical) that impart certain metal-specific properties to the surface of a metallic or non-metallic substrate. The economic advantage of these techniques is that, with a relatively small quantity of metal, it is possible to combine on the surface of the substrate properties that are a priori exclusive to the substrate and to the metal. This makes it possible to mechanically reinforce ultra-thin materials while retaining their flexibility, or to make the surfaces of insulating materials electrically conductive.
These techniques can also be used to protect against corrosion, and to create passive (RFID chips) or active (sensors) electrical devices. The physico-chemical compatibility of materials with the chosen technology will influence the deposit. This will be assessed in terms of adhesion, morphology, appearance and electrical properties. In addition to cost, the key parameters for industrial applications are precision, capacity and the environment to be used. The following is a review of surface metallization methods and techniques (physical, chemical, direct or indirect). The performance of each of the techniques presented is developed. This article can be used to guide users' technical choices, taking into account the method's potential, the constraints it implies and the intended application.
At the end of the article, readers will find a glossary of terms and a table of acronyms and symbols.