A wireless power supply includes a multi-layer shim assembly. Each shim aids in alignment of coils and routing of conductors in a multi-layer coil array. A shield or PCB can be used as part of the multi-layer shim assembly. Wires can be routed through channels to the edge of the shim assembly or wires can protrude through a portion of the multi-layer shim assembly. Traces can be used to route current through the multi-layer shim assembly. Plastic shims can be created by over-molding coils with plastic.