Automated workpiece carrier

FIGURE 4.20 Automated workpiece carrier in an SMD pick piace machine... 

TABLE 4.7 Properties of the Kinematics of the Automated Workpiece Carrier... 

FIGURE 4.21 Automated workpiece carrier in SMD pick place machine Siplace HF... 

Carrier thermal mass or, more accurately, capacity becomes important when work-piece carriers (Fig. 4.22) are used along the entire production line. The soldering proces s in particular is very much affected by this thermal capacity. The temperature profile has to be adapted to ensure dependable electrical and mechanical interconnecting that will also result in the requisite reliability. If the choice is going to be in favor of an automated workpiece carrier, it is important to bear in mind that the integrated drives and the electronics are not suitable for the soldering process. 

It may well be necessary to adapt an optical inspection system to accommodate the three-dimensional layout of MID process surfaces. Class 2l D MID can be inspected without additional kinematics and adaptation of the optical inspection system. This holds true only if the process surfaces are plane-parallel in the inspection plane of the sensor array. Classes n x 2D and 3D call for changes to the AOI system if the electronic components are widely spaced. This could well mean integrating an extra handling and positioning unit for MID, for example an automated workpiece carrier. 

Automated production requires a workpiece carrier that can be used all the way along the production line. Consequently, the design is such that the carrier can be conveyed by the printed-circuit board conveyor to all the machines in the process chain. The appropriate number of workpiece carriers is required if production is to be continuous. An interface for energy supply and communication between the automatic machines and the workpiece carrier is necessary, particularly for the dispensing unit and the automatic placement machines. The electronics built into the workpiece carrier render it unsuitable for reflow soldering, so a handling step has to be included so that the MID can be lifted on to a separate, passive workpiece carrier for this process. This transfer can be manual or by means of an industrial robot such as the Scara robot. 

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