Mutual diffusion at heterogeneous interfaces in co-fired composite MLCCs

Interdiffusion at the heterogeneous interfaces in composite multilayer cera mic capacitors (MLCCs) was investigated by scanning electron microscopy (SE M) and energy dispersive X-ray analysis (EDX). The results show that the mo vement of silver at the interface only involves physical migration, which c an be controlled mainly by the sintering characteristic of the ceramic. Bef ore the open pores in the ceramic change into closed pores, the silver migr ates by vapourisation. In addition, interdiffusion between different dielec tric layers may be affected by the sintering temperature and time and parti cularly by compositional gradients. So by lowering the sintering temperatur e and designing the elemental compositions of neighbouring dielectric layer s, interdiffusion can be suppressed and reliable processing of composite ML CCs achieved.