DocID025706 Rev 1

11/18

AN4428

Quality assurance

18

Figure 7. 3 x 4 new design nozzle

This design ensures that the holes for the vacuum and the air blow are always away from

the porthole of the device (4 vacuum ports at the corner of the device). Additionally, the new

design has also a recess, in the form of a cross, allowing the porthole to be left always at

atmospheric pressure. Under these conditions, the membrane will not suffer any sudden air

disturbances during the picking or placing of the device in the tape and reel. Figure 8 shows

the detailed mechanical dimensions of the new picker, the positioning of the vacuum holes

and the width of the recess.

Figure 8. Picker mechanical details for HLGA 3 x 4 microphones

The safe areas of the 4 x 5 and 3 x 4 microphones are identical and differ only in the

dimensions. The safe area of the 4 x 5 microphones includes the safe area of the 3 x 4

microphones; hence, despite this difference, the 4 vacuum port nozzle can be used for both

microphone packages. The following figure shows the usage of the 4-hole picker in the ST

production line (finishing).