00195982-03_SM_SWS_EN.pdf - 第270页
12 Wafer stretcher 12.2 Detailed description of "wafer stretching" procedure 270 Service Manual SIPLACE Wafer System (SWS) 11/2018 12.2 Detailed description of "wafer stretching" procedure Fig.367: ●…
12 Wafer stretcher
12.1 Explanation of the wafer stretcher
Service Manual SIPLACE Wafer System (SWS) 11/2018 269
Fig.365:
After the downholder plate (A) has moved up (R=retract) and the clamp has been opened, the
wafer foil sags (R). A wafer with an excessively sagging foil can not be moved back into the
magazine.
The IN19 sensors check how far the wafer is sagging. The maximum permissible wafer foil sag is
<9mm!
The setting for the IN19 sensors to the maximum permissible sag<9mm is described in a separ-
ate chapter.
Once the clamp and the downholder plate have been opened, the stretched wafer foil is warmed up
by the heater module (H). This shrinks (T=tension) the wafer foil (sag less than 9 mm) so that it is
tensioned and can be moved back into the magazine.
Fig.366: SIPLACE SWS wafer stretcher with stretched wafer foil
1. Stretched wafer foil in the SIPLACE SWS wafer stretcher
12 Wafer stretcher
12.2 Detailed description of "wafer stretching" procedure
270 Service Manual SIPLACE Wafer System (SWS) 11/2018
12.2 Detailed description of "wafer stretching" procedure
Fig.367:
●
The wafer frame (WR) is positioned on the support strip of the clamping plate (KB).
●
The base (BASE) with the clamping ring (R) and the heating (heater) has a spacing of more
than 9mm!
●
The camera (C) is unable to clearly recognize a single die (BAD), as the distance between
dies is nearly 0.
●
This makes is impossible to guarantee reliable pickup and ejection due to the friction between
the die edges.
Fig.368:
●
The wafer frame (WR) is now moved downwards until it is on the surface of the base (BASE).
●
The downwards movement of the clamping plate (KB) means that the wafer frame (WR) is no
longer on the support strip of the clamping plate but is instead pressed against the surface of
the basic unit (BASE) by the underside of the clamping plate, in other words, it is clamped!
12 Wafer stretcher
12.2 Detailed description of "wafer stretching" procedure
Service Manual SIPLACE Wafer System (SWS) 11/2018 271
Fig.369:
●
The clamping ring (R) is now moved upwards.
●
This "stretches" the wafer foil (stretch).
●
This stretching forces an expansion of the space between the dies (X).
●
The camera (C) can now clearly recognize the die (GOOD).
●
This space (X) guarantees a reliable ejection and pickup process as the dies no longer touch
and the die edges no longer rub against one another ("chipping").
Fig.370:
●
The die ejector moves upwards until the surface of the cap touches the wafer foil.