Handling robots for high-volume microassembly - an economic and technological comparison of different kinematic principles

High-volume microassembly on an industrial scale with a positioning accuracy better than ±5 ?m is currently achieved by either serial kinematic robots with stacked linear axes or parallel SCARA robots. Future microassembly applications will surpass the need for clean room laboratories and will for example also enhance car body parts in the automotive industry with new functionalities. In light of this, there is a need for the high accuracy used in microassembly to be applied to larger parts. Due to technical effects these microassembly robots cannot simply be scaled up. Therefore when excluding the technical issue of the sensor guiding system the question for the right choice of handling robot kinematic arises. The paper compares a gantry type microassembly robot with stacked linear axes and a new approach consisting of an articulated robot arm with a fine positioning unit at the tool tip. The existing systems and future scaled-up systems with similar kinematics are compared in terms of economic and technological benefits. Economic issues are acquisition cost and cost of ownership, but also the achievable cycle times for a given scenario. Furthermore, the ease of integration into existing manufacturing systems is compared. From the technical viewpoint, accuracy and repeatability are basic requirements for microassembly. The ease of control, the flexibility of the systems and the reliability are other technical issues considered