Investigation of Multilayer PCB Manufacturing Technology for Flip-Chip Mounting of Microwave Chip

The results of multilayer PCB manufacturing are presented. The presented technology allows obtaining a multilayer PCB with opened areas to inner layer, which can be used for further mounting of high frequency chips. As a commutation layer thin copper foil was used. Opened areas are obtained by mechanical milling of copper foil, which later be used as a top commutative or screen layer. As a dielectric layer high frequency prepreg RO4450B was considered. Commutation between layers of PCB obtained by through metallized holes. Inner layer was coated by electrodeposited gold, to improve further soldering quality. Pressure bonding was used to assembly multilayer package into one board. Electrical test result has shown that application of methods such as mechanical milling, pressure bonding and chosen materials can be used for manufacturing of multilayer PCB's with opened areas for component mounting.