High voltage connector types

Posted on May 8, 2016 by Randy

There are primarily five different high voltage connectors that are used on surface analysis systems. This post will explain the differences between them and provide information on how to connect them.

The high voltage connector types are:

BNC

MHV

SHV

10kV SHV

20kV RF

BNC_connector

This connector is not really considered a high voltage connector as it is only rated to 600V DC, but it is found most surface analysis systems on the specimen stage as the target connector.

MHV_cable_connector

The MHV connector looks similar to a BNC but it is slightly deeper and it has slightly protruding insulation on the make plug. MHV stands for miniature high voltage and this connector type is rated for up to 5kV and 3 amps. The MHV connector is common on older surface analysis components but it is not considered safe by today’s standards as it is possible to touch the male pin with a finger and get shocked. It is also possible to force a BNC cable onto a MHV connector.

Newer surface analysis components use the SHV (safe high voltage connector) which is rated at 5kV and 5 amps.

SHV_connector

The SHV has a recessed male pin and so it is not possible to touch the pin with a finger. The dimensions of the SHV connector make it impossible to connect it to a BNC or MHV connector. It is also designed so that the HV contact is broken before the ground contact when removing the cable.

10kV_SHV_connector

For higher voltages on components such as ion pump controllers the next voltage rating is the 10kV SHV connector.

The 10kV SHV connector is considerably larger than the 5kV SHV connector but is shares features such as the recessed pins.

20kV_SHV_connector

Finally, the 20kV RF connector is used on components such at 15kV dual anode x-ray sources. It is very similar to the 10kV SHV connector only larger.

All of these connectors need special crimp tools to attach them to cables.

Below are useful links for each connector type that include dimensions and assembly instructions:

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04-202 SED detector flange

Posted on April 4, 2016 by Randy

The model 97 SED preamp which is used on PHI scanning auger surface analysis systems converts secondary electron current into a video signal. It is designed so that it can be mounted onto a vacuum flange which houses a Channeltron electron multiplier. The 97 SED preamp housing is made of aluminum and if extreme care is not taken when mounting or removing the preamp from the detector flange it is possible to crack one of the three electrical feedthroughs. The picture below shows a broken connector on a 04-202 SED detector flange.

broken-ceramic-feedthrough

One of the difficulties of mounting the 97 SED preamp to the detector flange is that you can’t really see what you are doing as you slide the preamp over the flange. There are three larger holes inside the 97 SED preamp mount which go over the electrical feedthroughs on the flange. It is important that the electrical feedthroughs clear the holes on the 97 SED preamp mount and that the preamp is flush on the flange before the mounting screws are tightened. The mouthing screws should be tightened finger tight while holding the 97 SED preamp firmly against the flange, and then a little bit tighter which a screwdriver.

One way to make sure that the feedthroughs are not touching the holes in the preamp mount is to take the cover off the 97 SED before you mount it, and then put the cover back on after the preamp has been mounted.

Or, you can replace the cover with a piece of Plexiglas. In the pictures below I have modified a 97 SED preamp by removing the cover and using the cover as a template to mark a piece of Plexiglas so that it is the same size as the original cover. I drilled holes in the Plexiglas and then mounted it on the 97 SED preamp.

With a clear Plexiglas cover on the 97 SED preamp it is very easy to install the preamp onto the 04-202 SED detector flange with less chance of breaking one of the feedthroughs. And the Plexiglas still provides user protection from the high voltage which is present during normal operation of the preamp.

So whether you remove the cover when mounting the 97 SED preamp and then re-install the cover, or replace the metal cover with a Plexiglas one, by being able to see the feedthroughs as you install the 97 SED preamp you can safely mount the preamp with less risk of damage to the 04-202 detector flange.

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CASAXPS Scofield RSFs

Posted on March 10, 2016 by Randy

Neal Fairley of CASA XPS has found that it is possible to quantify PHI (Physical Electronics) XPS data using Scofield cross-sections modified for escape depth and angular distribution. The Scofield-based library is then populated with universal RSFs applicable to PHI data. Videos on the CASAXPA website illustrate this point and how all XPS instruments can now use Scofield derived RSFs regardless of which instrument or manufacturer is involved.

Below you will find links to videos that show CASAXPS in action. CASAXPS can help you quantify your XPS data and achieve accurate interpretation of the data. For more information on CASAXPS in the U.S. please contact RBD Instruments at [email protected] or by calling 541 330 0723.

I hope that you enjoy the videos!

Simulating Spectra:

Start Video Click Here or Click Here for mp4 Mode

Quantification of XPS Spectra:

Transmission function, Escape Depth Correction and Relative Sensitivity Factors

Start Video Click Here or Click Here for mp4 Mode

Quantification and the Influence of Overlay Material on Substrate Information

Start Video Click Here or Click Here for mp4 Mode

Quantification of PHI Versa Probe Spectra

Start Video Click Here or Click Here for mp4 Mode

Thin Film Estimate by Hill Equation:

Start Video Click Here or Click Here for mp4 Mode