Maintenance

This section describes maintenance operations that should be performed by the NanoFrazor owners. Do not hesitate to contact SwissLitho for clarifications.

Warning

Normal NanoFrazor users should not perform the operation described below as mismanipulation might seriously damage the NanoFrazor. Contact your Facility NanoFrazor manager if you think that your NanoFrazor needs maintenance.

High Speed Piezo Controller Offset Adjustment

Offset of the high speed piezo controller affect the close loop control system and allow conpensating for mechanical stresses on the positioning system.

Offsets need to be checked when some new component is attached to the piezo stage, when the room temperature changes by more than 5 °C, and when the total range of motion appears to be reduced. This usually manifest itself to the NanoFrazor users has unexpected behaviour of the piezo scanner, like oscillations. In some cases this will produce error in the NanoFrazor.

Offsets are checked by measuring the voltage present on the HV/10 connectors on the front of the High Speed Piezo Controller when the stage is in the zero motion position. The stage can be set to the zero position by setting DAC channels X Piezo, Y Piezo and Z Piezo to 0 V from the Electronics utility of the NanoFrazor software.

The Measured voltage at the HV/10 connector should be between -1 V and -0.5 V for each of the axes when set at zero motion position. If the measured voltage is outside of this range, adjust the front panel screw labelled “offset” (clockwise increase the offset). Use the provided screwdriver to adjust the offset, if the provided screwdriver is missing, an equivalent flat screwdriver can be used. Make sure that the screwdriver is correctly inserted in the screw before turning the screwdriver.

maintenance_offsets

Check the offset with provided multimeter. When the axes are in zero motion position the HV/10 output should give a voltage between -0.5 and -1 V. If necessary adjust the offset by rotating the offset screw till the volgage falls in the correct range.

Series and Pre-Amplifier Resistors

The series resistors and the pre-amplifier resistors are on the pre-amplifier board. The pre-amplifier board is inside the pre-amplifier box attached below the granite stone. The frame barrier (frame_barrier) needs to be removed, and the pre-amplifier enclosure (preamp_box) opened, in order to access the pre-amplifier board.

nfe_frame_barrier

NanoFrazor Explorer storage compartment. Frame Barrier drawn in red.

nfe_preamp_box

Image showing the pre-amplifier enclosure below the granite stone.

The instructions below describe how to access the pre-amplifier board.

  • Switch off all the NanoFrazor controllers.

  • Remove the 12 screws that hold the frame barrier and remove the frame barrier and the acoustic adsorbing foam on top of it. Use caution when removing the frame barrier as it might get stuck and damage the tubes of the pneumatic feet.

  • Remove the 4 screw holding the pre-amplifier enclosure front panel and remove the front panel.

  • Slide out the bottom panel.

    The pre-amplifier board is now accessible. preamp_board shows the board with the connectors for the series resistors and the pre-amplifier gain resistors highlighted.

    The series resistor are in socket Rd-R and Wr-R, where Rd stands for reader and Wr for writer. The pre-amplifiers gains are set by the resistors in JP5 and JP6 for the reader and writer pre-amplifier respectively.

nfe_preamp_board

Picture of the pre-amplifier board PP7.5b with socket for writer and reader series resistors as well as the corresponding pre-amplifier resistors highlighted.

Standard through hole resistors can be inserted in the sockets. Pins 1 and 2, and pins 3 and 4 of each socket are connected together. The resistors can be inserted, for example, between pin 2 and pin 3.

After modifying the resistors, the new values need to be set into the IVCurveParams configuration file. The file can be found in C:\SwissLitho\nanofrazor-pkg\app\lib\cfg\”Serial Number and name of your NanoFrazor”.

# Reader series resistor value
readerRSeries = XXXX;

# Writer series resistor value
writerRSeries = XXXX;

# Reader Electronics Gain
readerElectronicsGain = X

# Writer Electronics Gain
writerElectronicsGain = X

The resistor values are in Ohm. The electronics gains are calculated as

\[Gain = 1 + \frac{6000}{R}\]

where R is the pre-amplifier resistance.