Reliability of molded interconnect devices (MID) protected by encapsulation methods overmolding, potting and coating

Because of the growing use in peripheral applications, the climatic, mechanical and chemical stress on electronic devices is increasing. Consequently, appropriate protection mechanisms have to be developed and evaluated. Focus of this research work are protection methods for molded interconnect devices (MID). Potting and coating are conventional processes in standard PCB production. Materials and processes for applying the casting compounds and conformal coatings can be transferred to MID. Overmolding with thermoplastic material is a completely new approach. This paper presents a comparison of MID samples protected by overmolding, potting or coating. The reliability tests include thermal shock tests, drop tests and analyses of the media tightness of the system.