SECTION 7
43
Trouble symptom
Possible cause
Corrective action
9. Evaporant adheres to the
hearth. Or the hearth is
gouged on the filament side.
A. Insufficient cooling of the hearth
a. Check the water flow rate, which must be 10 /min or more.
b. Check the water temperature, which must be 25 C or lower.
c. Check the water flowing direction in the hearth.
See Fig. 3.3.
d. Check water for purity.
Water resistivity of 5 -cm or more is recommended.
B. The beam spot is deflected.
a. Position the beam spot at the center of the crucible so that heat
is dissipated uniformly in the radial direction.
10. Water leak The vacuum
gauge needle deflects in the
pressure range of 10
-4
when the hearth is rotated.
A. Defective seal for the hearth shaft. a. Replace the O-ring.
b. Check the surface of the shaft seal for scar. If it is severely
scarred, replace the part.
B. Defective cooling pipe seal for the
coils
a. Replace the O-ring.
b. Check the surface of the shaft seal for scar. If it is severely
scarred, replace the parts.
C. The hearth is perforated.
a. Replace the hearth.
11. Frequent abnormal
discharge.
Frequency of abnormal
discharge increases when
power is applied above a
certain level.
A. The gun shield is not provided.
a. Provide a gun shield referring to Figure 3.2.
B. Abnormal discharge due to gas
emitted from evaporant.
a. Use a high purity evaporant that emits less gas.
b. Decrease power and carry out degassing sufficiently.
C. Insulation film is formed on the
filament cable and causes charge
up.
a. Remove the filament cable and scrape off the film from the
cable or replace the cable. Check the high voltage feed-through
terminal to see if it is contaminated with eva-porant.
12. The high voltage meter
indication does not increase
when high voltage is turned
ON.
A. See Item 2.
a. See item 2.
B. Glow discharge due to high
pressure in the vacuum chamber.
a. Check the vacuum level, which must be 5 10
-2
Pa or lower.
C. Failure of EB power supply.
a. See the power supply instruction manual.
13. Evaporant splashes.
A. Excessive input power
a. Decrease the power to a level at which evaporation can be
performed smoothly.
B. Evaporant is powder.
a. Use a hot-pressed evaporant.
C. Excessively high beam power
density.
a. Decrease the power.
Summary of Contents for EGL-206M
Page 2: ...EB0007 03e...
Page 3: ...EB0007 03e...
Page 10: ......
Page 13: ...SECTION 1 3 Fig 1 1 Dimensional Drawing for EGL 206M EGL 406M...
Page 24: ...SECTION 3 14 Fig 3 1 Installation of two or more electron beam guns...
Page 26: ...SECTION 3 16 Fig 3 3 Typical water cooling piping arrangement...
Page 27: ...SECTION 3 17 Fig 3 4 Wiring arrangement in vacuum chamber...
Page 38: ...SECTION 5 28 Fig 5 1 Exploded view of emitter assembly and dimensional drawing for electrode...
Page 42: ...SECTION 5 32 Fig 5 2 Exploded view of EGL 206M EGL 406M...