Three-dimensional off-axis component placement and routing for electronics integration using solid freeform fabrication

Traditional placement of transistors in chips and components on printed circuit boards has been constrained in two dimensions. Routing of electrical signals in these devices has been extended to two and half dimensions by virtue of additional routing layers which are connected through vertical vias (i.e. four layer printed circuit boards or CMOS chips with seven layers of metal routing); however, truly three-dimensional off-axis component placement and routing have not yet been explored. Solid freeform fabrication provides the means of creating a dielectric substrate suitable for these electronics with sockets for components and channels for interconnect. Direct write dispensing of conductive inks or epoxies into these channels has been reported previously for electronics applications, but was generally confined to two dimensions in a fashion similar to traditional electronics. The current research describes a demonstration prototype in which components are placed off-axis to fulfill application requirements (for a three-dimensional magnetic flux sensor system) and where sections are routed off-axis as well – all of which provides new levels of design freedom for the implementation of electronics systems.