3 minimizing noise pickup from external cabling – INFICON IC/5 Thin Film Deposition Controller User Manual

Page 239

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IC/5 Operating Manual

In many cases, a braided ground strap is sufficient. However, there are cases when
a solid copper strap (0.030" thick x 1" wide) is required because of its lower RF
impedance.

Figure 11-3 System Grounding Diagram

11.2.3 Minimizing Noise Pickup From External Cabling

When a controller is fully integrated into a deposition system, there are many wire
connections, each a potential path for noise to reach the inside of the control unit.
The likelihood of these wires causing a problem can be greatly diminished by
adhering to the following guidelines.

Use shielded coax cable or twisted pairs for all connections.

Minimize cable lengths.

Avoid routing cables near areas that have the potential to generate high levels
of interference. For example, large power supplies such as those used for
electron beam guns or sputtering sources can be a source of large, rapidly
changing electromagnetic fields. Placing cables as little as one foot away from
these problem areas can significantly reduce noise pickup.

Be sure that a good ground system and straps are in place per the
recommendations in

section 11.2.2 on page 11-6

.

Ensure that all instrument covers and option panels are in place and tightly
secured with the provided fasteners.

NOTE: Always use shielded cables when making connections to the IC/5 rear

panel to minimize electrical noise pickup.

Back Panel

Ground

Stud

Earth

Ground

Transducer
Feedthrough

Vacuum System

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