  We describe the implementation of a three-dimensional Paul ion trap
fabricated from a stack of precision-machined silica glass wafers, which
incorporates a pair of junctions for 2-dimensional ion transport. The trap has
142 dedicated electrodes which can be used to define multiple potential wells
in which strings of ions can be held. By supplying time-varying potentials,
this also allows for transport and re-configuration of ion strings. We describe
the design, simulation, fabrication and packaging of the trap, including
explorations of different parameter regimes and possible optimizations and
design choices. We give results of initial testing of the trap, including
measurements of heating rates and junction transport.
