Fundamental investigation of cutting, forming and assembly injection moulding and their interdependence for manufacturing durable tight electronic systems

• Applicants: Professor Dr.-Ing. Dietmar Drummer; Professorin Dr.-Ing. Marion Merklein
• Subject Area: Plastics Engineering ; Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2012 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 217557128

The overall objective of the project is manufacturing media-tight plastic metal hybrids for electronic applications in a short process chain, taking into account the interdependence of the individual processes for metal and plastic processing. Based on the findings of the first project phase new fundamental research aspects can be derived which can be analyzed with the established testing facilities.Since a distinct deformation of metal inserts with embossed grooves during encapsulation was observed, the possibilities and limits of controlling material flow and material distribution by a multi-stage embossing process will be studied. The objective is to improve the rigidity of the insert while preserving its integrity and to achhieve a high forming accuracy of the embossed structures.Furthermore, the influence and the manufacturing of secondary surface structures will be studied. Those secondary structures will be applied in order to increase the bond strength in certain areas of the metal inserts. Such a hierarchical surface structure can be created by additionally structured embossing tools (e. g. by blasting or by µEDM) or etching technology. Furthermore the effect of a labyrinth seal or an extended sealing path with an increase in the bond strength of the interfaces will be combined and examined using pre-heated inserts.The second phase of the project focuses on the differentiated analysis of the characteristics of the polymer metal hybrids in regard to interactions between material and geometry in response to environmental stress. Previous investigations proved that different varieties of specimens are similarly tight shortly after the injection molding if ideal process parameters were chosen. However it is expected that significant differences between the differently treated workpieces will occur for increasing stressing and aging. Based on this information, the study of the long-term behavior of the plastic metal hybrid components, their property profile and the identification of failure mechanisms is also object of the project. In particular, the occurrence of thermo-mechanical stresses as a result of creep and relaxation as a function of the filler system under climatic and mechanical stress will be investigated. Conclusively, the findings of the two project phases will be united in a multidisciplinary, FE based methodology for load-adapted design of plastic metal hybrid components.

• DFG Programme: Research Grants