Workpieces such as chips are removed from a receiving plane by a transfer unit, which carries them to a delivery plane. The workpieces are transported in two segments during two phases, each workpiece being deposited between the phases on an intermediate station arranged in the region of the feed path. The transfer unit has two working heads, which simultaneously transport one workpiece from the receiving plane to the intermediate station, and another workpiece from the intermediate station to the delivery plane. The workpiece can be pivoted or rotated at the intermediate station so that its lower surface can be grasped by the depositing head.
For encapsulating an electronic component, in particular a semiconductor chip the component (3) at a distance is fastened onto a flat substrate (2). For this on the substrate there is deposited an elastomer layer (4, 9) which compensates the differing thermal expansion coefficients between the substrate and the component. A buffer material and/or an adhesive in liquid or pasty form is deposited from a dispenser and the component at room temperature is placed onto the buffer material and/or the adhesive. Before the final curing the buffer material and/or the adhesive is firstly subjected to a precuring. Subsequently the component by way of electrical leads is connected to contact locations on the substrate and lastly there is effected an encasing of all remaining hollow spaces including the electrical leads, with a protective mass.
An apparatus for mounting semiconductors contains a bonding station, whereby the bonding station comprises a wafer table for presenting the semiconductor chips, a substrate table and a pick and place system with a bondhead with a chip gripper. Part of the wafer table is located underneath the substrate table. The pick and place system has a first linear motor that comprises a rigidly arranged stator and a shuttle that can be moved in a first direction guided by first guide elements, and a second linear motor that comprises a rigidly arranged stator and a shuttle that can be moved in a second direction. The shuttle of the first linear motor has second guide elements that guide the shuttle of the second linear motor. The bondhead with the chip gripper is arranged on the shuttle of the second linear motor.
When mounting semiconductor chips, the semiconductor chips are presented on a wafer table where they are picked one after the other by a pick and place system, transported and placed onto a substrate that rests on a supporting surface of a substrate table. The wafer table is aligned diagonally to the supporting surface of the substrate table whereby part of the wafer table is located under the substrate table. The pick and place system comprises a shuttle with a swivel arm carrying a bondhead. The swivel arm is swivelled back and forth between two predetermined swivel positions whereby in the first swivel position a longitudinal axis of the swivel arm embraces the angle .phi. with the perpendicular to the supporting surface of the substrate table and whereby in the second swivel position the longitudinal axis of the swivel arm runs orthogonally to the supporting surface of the substrate table.
