Additive plasma metallization of spatial ceramic injection molded components

The molded interconnect device (MID)-technology offers many advantages as material saving or miniaturization by a high level of functional integration. However, the area of applications is limited because actually base materials largely consist of plastic materials that are produced by injection molding processes. Due to its high temperature and chemical resistance, ceramic materials have many benefits. Therefore, the production of ceramic circuit carriers by injection molding technology provides a high degree of freedom of design. Thus, injection molded spatial alumina substrates made of different ceramic feedstock materials were metallized by using a plasma-coating-technology. Analysis of the surface roughness indicated a strong correlation between feedstock particle size and the resulting surface structure. In addition, an increasing surface roughness alongside the flow path has been observed, which could influence the bond strength of the metallization. After application to the conductor tracks several passivation types protecting the copper layers were analyzed. To achieve a functional electrical circuit, electric components were installed by soldering paste and conductive adhesive. In environmental tests, the sample circuits built on a ceramic base were reviewed and assessed.