Statically Determined Gripper Construction

The current approach to reducing impact forces during component placement in micro-assembly is to couple the gripper with 5 Degrees Of Freedom (DOF) to the drive unit of the placement device, wherein the mass of the gripper has been reduced maximally. At the end of the placement motion the drive unit will move relatively to the gripper, as linear as possible given the limitations of the construction. During this motion generally stress builds up in the gripper and it becomes over-constrained due to the extra constraints added by the contact between gripper/component and the substrate. Due to this tension the gripper will start vibrating when the gripper rebounces or when the component is released, resulting in significant placement inaccuracies. A solution has been found to prevent the gripper from becoming over-constrained by adding an extra tilting member to the gripper, leading to a reduction of the placement inaccuracies.