Ulvac RFP-N - Adding a Fixed Capacitor

RF POWER SUPPLY and MATCHINGBOX
6. Matching Adjustment
75
TUNE(C1)
MATCH(C2)Coil(L)
RF-IN
RF-OUT
Adding①
Adding②
Load
6-2-3. Adding a fixed capacitor
When Pr is at minimum, it will be necessary to add a fixed capacitor if the position of the MATCH
variable capacitor is within 0% to 99% and the TUNE variable capacitor is near 0% or 99%. In this
case, add the following types of capacitors, and after doing so, ensure that the screws are not loose.
 When the TUNE variable capacitor is 99% and Pr is the minimum value, add the fixed capacitor
to "Add location ①".
* The fixed capacitor plate in the MBX is an option.
 When the TUNE variable capacitor is 0% and Pr is the minimum value, add the fixed capacitor
to "Add location ②".
* Add the fixed capacitor between the output section to the equipment side intermediate box and
the ground.
* When the fixed capacitor is added to "Add location ②", the capacitor will become the load and
matching may occur without discharge occurring, so please confirm that discharge is occurring
without problems.
* Damage, etc., due to the occurrence of abnormal current or abnormal voltage due to matching
without ignition such as that above is outside the scope of the warranty.
Warning
Be careful of withstand voltage and withstand current when inserting a capacitor in
parallel to the load. A fixed capacitor is a precision device, so shocks from falls or
excessive stress may damage it. When installing it, please do so without excessive stress
such as bending or twist it. Excessive tightening torque may also damage it. Please
tighten to a tightening torque of 147 N∙cm or lower. A vacuum variable capacitor is a
precision device that may be damaged from falls and vibrations, so use extreme care
when handling the matching box.
Figure 6-5 Locations to add the fixed capacitor