Ulvac EGO-40M Instruction Manual page 46

MULTI-HEARTH ELECTRON BEAM SOURCE ～EGO-４０M～
Trouble symptom
3. The beam spot is not visible in
the hearth. High voltage and
beam current are normal.
4. The beam spot sometimes
moves.
5. The beam spot moves toward
the filament with increase of
power.
6. The magnet indicator does not
light.
The deflection coil current is
normal.
7. The magnet indicator does not
light.
The deflection current does not
flow.
8. The anode plate is red heated or
melts.
9. Evaporant adheres to the hearth
or the hearth is gouged on the
filament side.
Possible cause
A. Poor adjustment of the EB power supply. a. Adjust the deflection coil current in accordance with the power supply
B. Incorrect wiring of the deflection coils.
C. Layer short or short of the deflection
coil.
A. Unstable focus current of EB power
supply.
A. High voltage drops with increase of
power.
A. The deflection coil or lead is shorted.
A. The deflection coil or lead is broken.
A. Incorrect dimensions of the emitter
assembly.
A. Insufficient cooling of the hearth
B. The beam spot is deflected.
Corrective action
instruction manual. The beam spot can be nearly centered by adjusting
the deflection coil current to 1.2A and both of X-axis and Y-axis current
to zero when the high voltage is 10 kV.
a. Check the wiring referring to Figure 3.4.
a. Check the resistance of the deflection coil.
The normal resistance is 2.6
a. Check the deflection coil lead for contact and insulation.
b. Failure of E/B power supply
a. The EB power supply appears defective. See the power supply
instruction manual.
b. Check the 3-phase input voltage to see if phase is open.
a. Check if the deflection coil lead is shorted to ground.
b. Check the resistance of the deflection coil.
( 2.6 10% at 20 C )
a. Check if the deflection coil lead is disconnected at the connection.
b. Check the resistance of the deflection coil.
a. Correct the dimensions as shown in Fig. 5.1.
Replace deformed parts.
a. Check the water flow rate.
b. Check the water temperature, which must be 25 C or lower.
c. Check water for purity.
Water resistivity of 5 -cm or more is recommended.
a. Position the beam spot at the center of the crucible so that heat is
dissipated uniformly in the radial direction.
39
7．TROUBLESHOOTING
10% at 20 C.
(See its instruction manual.)