Solenoidal micro coils manufactured with a wire bonder

We present for the first time the development of 3-D solenoidal micro coils using an automatic wire bonder. By developing a stable and repeatable bond process with insulated wire, micro coils with sub-millimeter diameter have been manufactured. The winding process for a single coil takes about 200 ms, whereas the manufacture of a 100-coil-array takes less than a minute. Micro coils with 4 windings and a diameter of 690 mum exhibit an inductance of 12.7 nH and a resistance of 580 muOmega at 300 MHz. These values correspond to a quality factor of 41 and compare favorably lo state-of-the-art micro coil manufacturing technologies.