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Microdot Coaxial Feedthroughs and Components

Grounded-shield Microdot and Microdot-BNC CF feedthrough Show CF Feedthroughs for Grounded-shield Microdot and Microdot-BNC CF feedthrough
CF Feedthroughs
Grounded-shield Microdot and Microdot-BNC ISO feedthrough Show ISO KF Feedthroughs for Grounded-shield Microdot and Microdot-BNC ISO feedthrough
ISO KF Feedthroughs
Male and female Microdot S-50 connector to cable Show UHV Cables for Male and female Microdot S-50 connector to cable
UHV Cables

UHV Microdot Feedthroughs

The Microdot coaxial interface, developed for aerospace and instrumentation applications, is a small circular connector, which is sometimes mistaken for the slightly larger SMA coaxial connection.  In its most common configuration, the S-50 series (the vacuum microdot feedthroughs offered on this site), it uses a No. 10-32 UNF (.190-32) thread.  Male connectors are fitted with a 0.030/.033 diameter pin and jacks have the female mating socket receptacle.  It is commonly used in conjunction with high-frequency, low noise, 50-Ohm instrumentation signal lines in accelerometers, and various transducer applications.

Microdot Feedthrough Construction

Accu-Glass Products' Microdot and "between-series" BNC-Microdot coaxial feedthroughs are constructed with grounded shields, where the feedthrough shield and flange are electrically common. 

Microdot Feedthrough BNC-Microdot "between-series"

Microdot-BNC feedthroughs offer a simple means of transitioning between BNC and Microdot wired applications, or vise versa.  The BNC-Microdot feedthrough is often used in conjunction with crystal sensors to monitor deposition thicknesses of in-vacuum coating applications.  Microdot cable assemblies, connectors, and wiring accessories are also offered on this site.  Rated for High Vacuum (HV) and Ultrahigh Vacuum (UHV) applications.

Warning — SMAs, with .250-36 thread and .035/.037 pin diameter, are often mistaken for Microdot  S-93, connectors with .250-32 threads and .030/.033 pins. To avoid possible damage to one or both connector interfaces, these connectors should never be cross-mated. Compare Microdot ® and SMA differences below...

Microdot, SMA Interface ComparisonGlow Discharge Graph

Features

  • Microdot® and BNC Coaxial Interfaces
  • Single and 'Between Series' Configurations
  • Kapton® insulated, 50-Ohm cables
  • High temperature rated to 250°C
  • UHV compatible construction
  • Conflat® and ISO KF compatible mounts
  • Air service cables / connectors
  • Custom solutions on request

     

Specifications

Electrical 
Voltage 1, Maximum500 VDC
Current, Max @ 20°C2 A
Material 
Shell304 Ss
Pin, Ni-PlatedSs / Mo
Insulation, CeramicAlumina
Connector, Vacuum 2 
   BNC, Ni-PlatedBrass / PEEK
   Microdot, Au-PlatedBrass / PEEK
   Cable InsulationKapton®
Connector, AirComposite
Vacuum Range 
UHV, Ultrahigh vacuum1x10E-10 Torr
HV, High vacuum1x10E-8 Torr
Temperature Range3 
Feedthrough, Single Ended250°C
Flange, Conflat®450°C
Flange, ISO150°C
Connector / Cable, Air165°C
Connector / Cable, UHV250°C
Thermal Gradient, Maximum25°C/minute
Notes 
  1. Electrical ratings are maximum test values, with feedthrough's vacuum side at ≤ 1x10-4 Torr. Feedthroughs are intended for instrumentation applications carrying low level signal voltage/current.
  2. PEEK is a polyether ether ketone thermoplastic.
  3. Overall assembly ratings must be adjusted to that of its lowest rated component. For cryogenic service, the lowest recommended temperature is -200°C