00195982-03_SM_SWS_EN.pdf - 第321页
12 Wafer stretcher 12.8 Setting the sag sensor IN 19 Service Manual SIPLACE Wafer System (SWS) 11/2018 321 12.8.1.2 Sag sensor assembly function The transmitter S emits a light beam which is received by the receiver R. T…
12 Wafer stretcher
12.8 Setting the sag sensor IN 19
320 Service Manual SIPLACE Wafer System (SWS) 11/2018
12.8 Setting the sag sensor IN 19
12.8.1 General information about the sag sensor
12.8.1.1 Sag sensor assembly structure
Fig.451:
The sag sensor assembly consists of:
1. Transmitter S
2. Receiver R
3. Sensick WLL180T analysis unit
12 Wafer stretcher
12.8 Setting the sag sensor IN 19
Service Manual SIPLACE Wafer System (SWS) 11/2018 321
12.8.1.2 Sag sensor assembly function
The transmitter S emits a light beam which is received by the receiver R.
The value shown on the analysis unit depends on the intensity of the light beam sent by the trans-
mitter S to the receiver R.
The following functions are on the analysis unit Sensick WLL180T:
Fig.452:
1. Fiber optic cable from transmitter S and receiver R
2. Fiber optic cable lock
3. Selection button (+ / -)
4. Mode button
5. Teach button
6. Set switching threshold value (green)
This value must be taught.
If the light intensity received is under this switching threshold value, no signal will be emitted.
7. Light intensity display at receiver (red)
This value shows how much light intensity sent by the transmitter S actually arrives at the
receiver R.
It is assumed that the transmitter S and receiver R are optimally set for the installation condi-
tions, so that these values can be taken as absolute.
8. OUT signal
Fig.453:
If the light intensity value at the receiver R (red display (2)) is greater than the set switching
threshold value (green display (1)), then the following applies:
●
The light beam has not yet been interrupted properly and there is no risk that the wafer foil will
be tensioned on the base unit.
●
A signal (OUT shines orange (3)) will be emitted and the wafer may be pulled into the wafer
lift by the gripper.
12 Wafer stretcher
12.8 Setting the sag sensor IN 19
322 Service Manual SIPLACE Wafer System (SWS) 11/2018
Fig.454:
If the light intensity value at the receiver R (red display (2)) is less than the set switching threshold
value (green display (1)), then the following applies:
●
The light beam has been interrupted and there is a risk that the wafer foil will be tensioned on
the base unit.
●
No signal (OUT does not shine orange (3)) will be emitted and the wafer may not be pulled
into the wafer lift by the gripper.
12.8.1.3 Explanation of light intensity in connection with foil sag
Light beam not interrupted
Fig.455:
●
The transmitter S (1) and the receiver R (2) are fitted just above the expansion ring (ring).
●
The light beam from transmitter S (1) is not totally emitted as the clearance height for the
wafer change means the transmitter S (1) may not be too high.
●
For this reason, the whole light beam is not emitted from the transmitter and is deflected or
blocked by the expansion ring.
●
Due to the dispersion of the light beam, the receiver R (2) only receives a certain percentage
of the light intensity (I) compared to the amount of light emitted.
●
When the setting and alignment between the transmitter S (1) and receiver R (2) is optimal,
the light intensity value displayed on the analysis unit is maximum (absolute).
●
The aim when mechanically aligning the transmitter S to the receiver R is to achieve the
highest possible light intensity value.
●
This value is seen as 100%.