Drum Coater with Reel-to-Reel Mode Enabled by Stick-Slip-Motion

A successful method for the fabrication of coated conductors is winding the tape helically around a drum and rotating it in vacuum between a deposition zone and an oxidation zone. This is a batch process, however, so that the conductor length is limited by the size of the drum. Scaling up then means ever larger vacuum systems. This problem can be overcome by using a continuous process with co-rotating reels where the tape is shifted along the drum surface. This shift can be easily accomplished by inducing a stick-slip motion. As a byproduct, the uniformity is increased because the conductor is subjected to the same conditions over its entire length. Here, an experimental model is described that has reached tape speeds of 2 m/min, enough for production. The corresponding theory indicates that the parameters can be optimized even further.