Test Substrates

© Fraunhofer ISIT / photocompany, Itzehoe

Fraunhofer ISITs wafer portfolio is complemented by corresponding FR4 substrates. Each substrate contains 24 chip positions divided in three groups. Chips can be placed either on the front or back side of the substrate depending on the desired pad configuration. The “FC 475 DDC” test board for example, features contacts for flip-chip connections on the front side and wire bonding on the back side.

Each chip position is surrounded by measurement pads, enabling easy continuity checks. In case of faults, the defective chip area can be located.

Detailed measurements of the electrical connections can be performed with the measurement board developed by Fraunhofer ISIT. In manual standalone mode visual feedback is used to mark connected daisy chains. In combination with a computerized measurement card, the resistances of each daisy chain as well as the contact resistance of selected interconnects can be measured. A graphic user interface is used to visualize the measurement results.