00195982-03_SM_SWS_EN.pdf - 第499页
18 Appendix 18.5 Touch-down sensor rev. 1 Service Manual SIPLACE Wafer System (SWS) 11/2018 499 18.5.3 Function 18.5.3.1 Height measurement of nozzle 1 or 2 in Z lift. When taking the machine into operation and before fi…
18 Appendix
18.5 Touch-down sensor rev. 1
498 Service Manual SIPLACE Wafer System (SWS) 11/2018
18.5 Touch-down sensor rev. 1
18.5.1 Function description
The touch-down sensor (Hall sensor Micronas type:815K) is a universal magnetic and program-
mable field sensor.
There is a magnet positioned at approx. 400µm distance from the sensor, which is aligned with its
plus pole towards the sensor.
When the sensor has a distance of 400µm to the magnet, the sensor issues voltage of approx.
4.0V. The basic output voltage should be between 3.0V and 4.2V.
When the voltage is over 4.75 V, the sensor is saturated and will not issue any more changes in
voltage.
The touch-down movement sees the nozzle and the magnet being pressed upwards against a
spring. The distance of the magnet to the sensor increases and the output voltage of the Hall
sensor decreases, linear to the distance.
A change in distance of 100µm produces a change in voltage of 0.25V. This produces a change
in analog-digital conversion of 100 count.
18.5.2 Electrical connections
The two touch-down sensors are supplied via a special high-flex round cable (4 pin) through the
hollow shaft (torsion 180°) to the distributor board AD-HC.
The two flat-flex cables run from the AD-HC board to the AD-HCS sensor boards, placed with the
Hall sensor 815K (placement variant left and right). The flat-flex cable is integrated into the Z move-
ment (pickup) of the two nozzles.
Since the cable is subject to high stress (lift 7-8mm, 6,000cycles/h), it is important to avoid any
damage or folding of the flex cable.
The electrical connection of the touch-down sensors on the USB-IO board (cable 4 pin) is as fol-
lows:
●
Brown = terminal 5V
●
Green = terminal AI4 (analog input touch-down sensor nozzle 1)
●
Black = terminal AI5 (analog input touch-down sensor nozzle 2)
●
Blue = terminal AGND
The supply voltage for the sensors us 5 V against AGND.
The voltage output for the sensors can be picked off at the terminals A14 (nozzle 1) or A15 (nozzle
2) against the terminal AGND.
Since the analog evaluation of the sensors takes place at the USB-IO board and the motor move-
ment takes place at the Galil motor controller, there is a digital output signal from the USB-IO board
to the motor controller, directly to the latch inputs, IN4 = die ejector, IN10 = flip Z, IN12 = flip X. This
output signal is made available through a hardware modification to the USB-IO board.
This means that we bypass the communication times for the USB interface and have a direct signal
for the encoder value storage.
18 Appendix
18.5 Touch-down sensor rev. 1
Service Manual SIPLACE Wafer System (SWS) 11/2018 499
18.5.3 Function
18.5.3.1 Height measurement of nozzle 1 or 2 in Z lift.
When taking the machine into operation and before first pickup of a die, you need to calibrate the
height of the two nozzles.
This calibration is also performed during a nozzle change.
The measurement sensitivity in µm can be specified via the menu and is then sent to the USB IO
board when you give the measurement/star command.
Measurement sensitivity setting in the menu = 10 to 30 µm.
The output voltage for the touch-down sensor must be in an output measurement window. The
minimum value is 1100 count, the maximum value is 1850 count.
If this is not the case, an error message will be sent to the control computer. The measurement will
then not be started. The output signal will remain at "1".
Before beginning height measurement, the relevant measurement program (nozzle 1 or 2) needs to
be started at the USB IO board. The USB IO sets the output signal for the latch inputs (IN4, IN10,
IN12) to "0". This is the release for the motor start.
The die ejector vacuum will be switched on.
The motor tool Z then moves slowly downwards from a safe starting measurement position. This
starting position must be at least 3 mm under the tool Z rotation height, as the optical component
check (component sensor) switches the same output signal for the latch input. The optimum start-
ing position for the nozzle is approx. 1 to 1.5mm above the chip surface. The motor will start with
4000count (2mm) downwards.
The maximum tool position is around the same in all machines and is therefore not exceeded.
When the nozzle touches the chip for the first time, the analog input changes (A14 or A15).
If the change in voltage (measurement sensitivity approx. 10-30µm) is large enough, the output
signals (USB-IO) will immediately switch the latch inputs (IN4, IN10, IN12) to "1". The latch input
immediately freezes the Z axis encoder value.
The Z motor will immediately receive a stop command.
The calculated offset upwards gives the exact Z height.
If the measurement-travel speed is "SPF=5000", the motor braking distance after the stop com-
mand will be approx. 90µm.
If the measurement-travel speed is "SPF=2500", the motor braking distance after the stop com-
mand will be approx. 50µm.
If the USB-IO output does not switch in the required travel route, an error message will then be is-
sued. A command at the USB-IO will then reset the output signal for the latch input to "1".
18.5.3.2 Distance measurement - nozzle 1 in X lift:
When measuring the X lift (motor 8) to the nozzle of the die attach rotor, the component sensor is
switched off (OUT12). This means that the output signal for the USB-IO board is free for height
measurement. The measurement with nozzle 1 is performed with a chip attached by suction. Meas-
urement will be started at a safe distance (1‑2mm) to the die attach nozzle. The procedure is
the same as that for the Z direction.
The component sensor will be switched on again after the distance measurement.
The light beam from the component sensor may not be interrupted by the nozzle in the Z axis. The
component sensor will calibrate the laser beam during the switch-on procedure.
18 Appendix
18.5 Touch-down sensor rev. 1
500 Service Manual SIPLACE Wafer System (SWS) 11/2018
18.5.3.3 Height measurement needle - die ejector:
To measure the height of the needle, you need to start measurement 2x. The first measurement
will be performed with the motor flip Z.
The die ejector vacuum will be switched on.
The position of the chip surface is approached with the nozzle and measured (see description:
"height measurement - nozzle 1 or 2 in Z lift").
The nozzle spring has then compressed by approx. 50-100µm. A new measurement is then star-
ted in the USB-IO. The USB-IO sets the output for the latch inputs (IN4, IN10, IN12) to "0". This is
the release for the motor start. The die ejector motor starts from the home-index position. The max-
imum starting lift is 2000count (2000µm).
If the change in voltage (measurement sensitivity approx. 10-30µm) is large enough, the output
signal = "1" will immediately switch the latch inputs (IN4, IN10, IN12). The latch input immediately
freezes the die ejector axis encoder value. The die ejector motor will immediately receive a stop
command.
The calculated offset downwards gives the exact needle height.
18.5.4 Function procedure - USB-IO program
The USB-IO control receives the start signal for the measurement program nozzle 1 or 2 from the
control computer.
After this, the output value for the sensor is read 10x within 1ms to form an average value. The two
highest and the two lowest values are not included in this calculation. The smoothed values are
then saved for the final comparative calculation. The analog values must be in the measurement
window between 1100count and 1850count. If this is not the case, an error message will be is-
sued at the control computer.
If the analog value is valid, the USB-IO sets the output signal for the latch inputs to "0" and meas-
urement can begin. The latch input signal "0" (IN4, IN10, IN12) is the release for the motor start.
When measurement starts, the analog values for the touch-down sensor are constantly read in.
One read-in process takes approx. 60 us. The last three measurements are added after each read-
in process and divided by three. The value currently calculated is then subtracted from the saved
value.
If the result is greater than 10count (measurement sensitivity = 10µm), the output for the latch in-
puts (IN4, IN10, IN12) will be immediately switched to "1".