Ulvac EGL-206M Instruction Manual page 48

1. Make functional check of the flow switch in the following way before starting
the coater. Close the cooling water valve temporarily to check that the GUN
WATER indicator goes out. Then slowly open the valve to feed water and
check that the indicator lights when the flow rate exceeds the necessary
minimum value mentioned in the electron beam gun instruction manual. If the
flow switch does not operate properly, adjust the operating point.
The minimum flow rate is 10 L/min.
2. The life of the insulator and filament largely depends on the
conditions of the electron beam gun. This section describes the frequency for
checking the insulator and filament so that the life expectancy under user's
operating conditions can be known.
3. The filament lead, made of copper, tends to be worn by ionized gas particles in
sputtering. A worn lead may be heated and broken if the electron beam gun is
operated at high power. Loose connection causes an unstable filament current
because of the contact resistance and will result in an unstable beam current.
In that event, the connection will be heated. The lead is subject
sputtering. Replace it when the thickness of the sputtered portion has become
80 of the initial size.
4. If the lead of the X-axis or Y-axis for the deflecting coil is within 20 mm from
the filament lead, discharge will take place between the two wires and may
break down the magnet control circuit. Make sure the lead is not in a state
susceptible to short with ground or to breakage at the joint with the deflecting
coil feed-through or terminal. Use care especially after change of filament or
cleaning of the crucible area.
5. The high voltage feedthrough is heated with heat from the electron beam gun.
This temperature cyclic makes screws easily loosened and periodical
retightening necessary.
6. The emitter assembly gets very hot during operation. The temperature cycle
tends to loosen screws and the screws must be retightened periodically.
7. Imperfect grounding can be very dangerous. Check the connections of the
ground cable and avoid use of an unnecessarily long ground cable.
grounding requirements, see the E/B gun power supply instruction manual.
8. It is recommended to use distilled water for cooling maintain cooling efficiency.
Generally, city water or well water can be used as it is, but its quality must be
less than 100 ppm (hard water of which salts contents in one liter are 100 mg as
converted to calcium carbonate). Water of poor quality tends to deposit fur on
SECTION 6
NOTES
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