Design and technology of 3D MMICs using multilayer structures

Multilayer monolithic microwave integrated circuit (MMIC) structures using polyimide as insulating dielectric layer has been utilised to demonstrate a range of MMICs. The polyimide layer formation, curing and dry etching processes have been investigated in an attempt to obtain high quality dielectric layers suitable for MMICs applications. By employing this technique, MMIC design and circuit routings become much easier and conventional microstrip transmission lines and lumped passive components can be realised with effective use of the substrate material.