Ultrashort Pulse Laser Bending

Accurate positioning of smallest components represents an up-to-date key assignment in micromanufacturing. It has proven to be most time and cost efficient to initially assemble the components with widened tolerances before precisely micro-adjusting them in a second step. The use of laser induced contact-free deformations for micro-adjustment of functional components such as recording heads or sensors has already been established for several industrial applications. The fact, however, that laser bending or shrinking processes normally rest upon thermal tensions has been found unfavorable. To overcome the drawbacks of thermal laser bending, such as time consuming cooling periods or thermally induced damage, a new laser micro-adjustment method, based on a fundamentally different mechanism is currently being researched and qualified. Instead of temperature gradients, specific effects achievable by surface structuring with ultrafast laser systems are utilized to achieve highly accurate micro-deformations. To explain the background of this novel technique, fundamental particularities of ultrashort-pulse laser material interactions are discussed using both theoretical models and practical observations. Results from extensive experimental studies are presented, revealing the potential of micro-adjustment with ultrafast lasers, concerning its precision, range and positioning speed.