A packaged integrated circuit (IC) device includes a first set of stacked die having a first IC die, a first inductor in the first IC die, an isolation layer over the first IC die, a second IC die over the isolation layer, and a second inductor in the second IC die aligned to communicate with the first inductor, and a second set of stacked die having a third IC die, a third inductor in the third IC die, a second isolation layer over the third IC die, a fourth IC die over the second isolation layer, and a fourth inductor in the fourth IC die aligned to communicate with the third inductor. The isolation layer extends a prespecified distance beyond a first edge of the second IC die, and the second isolation layer extends a second prespecified distance beyond a first edge of the fourth IC die.