Mini and Sub-Mini Multi-CF Vacuum Chamber Systems and Accessories

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Introduction

Kimball Physics Miniature (Mini) and Sub-Miniature (Sub-Mini) Multi-CF^TM Conflat (CF) sealing surface UHV Vacuum System Components bring unique advantages to your research and development projects or commercial products. Chambers with minimized external size and weight provide unique opportunities for integration into your equipment and systems.

These components include small vacuum chambers and instrument housings, with optimized usable internal volume, which reduces vacuum volume pumping load and conserves the external volume footprint and weight, especially when these constraints can add significant costs (such as launching your device into space).

We also have a large selection of flange multiplexers, flange adapters, flange feedthroughs, and other mini and sub-mini flange components to make it easy to build your system. For most research scientists and engineers, the challenge is finding (or creating with significant costs) the vacuum infrastructure components to create your mini (1.33” CF ports) or sub-mini (0.95” CF ports) UHV system.

Please reach out to Kimball Physics to engage our specialists if you need a custom system for your specific application.

In the sections below, we will cover the details of each of these component categories, including the most recent parts that have been introduced to our mini and sub-mini systems.

Kimball Physics provides the components for Miniature and Sub-Miniature Systems, including:

• Multi-CF^TM sealing surface UHV Vacuum Chambers and Housings with 1.33” and 0.95” CF sealing surface ports included (with some exceptions).
• Multi-CF^TM Multiplexers, with 2.75” CF base and either five (5) 1.33” CF ports or five (5) 0.95” CF ports. Other configurations are also available.
• 95” Conflat Flange (CF) Feedthroughs to provide high voltage, high current electrical connections for powering, controlling, or acquiring the data from your system or device
• CF Flanges, including flange blanks, flange adapters, and extended flanges
• 95” CF Viewports with UV Grade Sapphire
• Internal Mounting System (internal grooves, mounting clamps, and eV Parts) for internally mounting components and creating prototypes to be placed inside the vacuum space (when a 2.75” CF port or larger is incorporated into the system)
• External mounting options

Multi-CF^TM Port CF Sealing Surface UHV Mini and Sub-Mini Vacuum Chambers

Kimball Physics UHV (Ultra-high Vacuum) Vacuum Chambers are precise, modular, multi-port fittings and housings that utilize integrated ConFlat^® (CF) sealing surfaces at each port. We refer to them as MCF^TM or Multi-CF^TM vacuum chambers (also referred to as fittings or housings) and they are available in several sizes and configurations. These compact designs are generally compatible with most other vacuum fittings in the industry with the bottom line of facilitating the efficient creation of clean reliable vacuum environments.

Several miniature “Mini” MCF^TM Multi-CF sealing surface UHV Vacuum Chamber configurations have been available from Kimball Physics for nearly two decades in miniature sizes that include main or primary 1.33” CF ports, such as our 1.33” Spherical Cubes and Triangles.  Most of our other larger vacuum chambers include 1.33” CF secondary ports in their design.

 

 

Examples of 1.33” CF Spherical Cube and Triangle miniature vacuum chambers.

In addition, we have several MCF^TM chambers that are based on 2.75” CF main sealing surfaces, in the form of spherical triangles, cubes, hexagons, and octagon geometries that we also consider as miniature chambers, with many of them also including 1.33” CF secondary ports.  The 2.75” CF port enables them to be compatible with our flange multiplexers, which cost-efficiently increase the number of ports available.

The 2.75” CF ports also include annular channels, or Grabber Grooves, that provide the convenient capability for internal mounting of your devices and that are compatible with Kimball Physics Groove Grabber Clamps and our eV Part set for prototyping your concepts or connecting and mounting your devices within the chamber or housing.

Examples of various 2.75” CF Spherical Cubes, Spherical Hexagons, and Spherical Triangle UHV miniature vacuum chambers

We continue to evolve our MCF^TM designs and have recently introduced chambers with main or primary 0.95” CF ports as well as chambers with 3.38” CF and 2.75” CF main port designs with multiple 0.95” CF secondary ports. MCF^TM chambers are available in our versatile and popular design configurations (Spherical Cubes, Spherical Hexagons, and Spherical Octagons) and we provide more detail in the section below.

Examples of 0.95” CF Spherical Cube, 2.75” CF Spherical Hexagon and 3.38” CF Spherical Octagon UHV sub-miniature vacuum chambers with 0.95” CF ports.

Kimball Physics’ Multi-CF^TM UHV fittings are designed as both instrument housings and as vacuum chambers, with the specific design intent to:

• Conveniently support a diversity of internal apparatus
• Permit complex port arrangements
• Maximize interior functional volume while remaining compact to minimize their external footprint
• Provide convenient internal access
• Improve pumping efficiency
• Follow a modular dimensioning system
• Cluster together in proximity

The Multi-CF^TM chambers are typically precision CNC fabricated from a monolithic (single piece) of 316L stainless steel with the CF sealing surfaces directly machined into this global structure. Custom chambers of similar configurations can also be fabricated from various grades of titanium.  This design approach optimizes 1) weight to structure (with high stiffness and resonant frequency), 2) the functional internal volume with minimized internal surface area and outgassing in high vacuum experiments, and 3) reduced external dimension for a given functional internal volume.

Titanium chambers, although more expensive, add significant additional benefits including very low magnetic permeability and minimized outgassing of hydrogen when pumping to extreme vacuum (XHV) levels. With titanium about half the density of stainless steel and similar in structural properties, these systems are also significantly reduced in weight.

This efficient use of volume to surface area (a spherical form) minimizes unusable internal space and allows more efficient pumping, while also minimizing the components external dimension footprint.

As previously noted, the ConFlat^® flange (CF) sealing surfaces are machined directly into the single global structure. This sealing surface, which utilizes a knife-edge geometry, is used with an interposed malleable copper gasket and provides both a seal and a stable structural connection between the flanges of various components.  Predictable seals for ultra-high vacuums (UHV) and even extremely high vacuums (XHV) that accompany very low pressure (< 10^-11 torr) applications can be reliably obtained over a broad range of temperatures.

Other features of our vacuum chambers that optimize UHV and XHV applications include highly polished mirror-like surfaces, with smooth rounded contour surfaces to minimize internal surface area and with few or no welds within the vacuum space (any welds, if present, are welded from the inner surface).

In the tables below, explore further information about the mini and sub-mini vacuum chambers that are available.

Table of various miniature and subminiature Multi-CF Vacuum chambers with port configurations.

 

Table with images of various miniature and subminiature Multi-CF Vacuum chambers with port configurations.

Please reach out to Kimball Physics to engage our specialists if you need a custom system for your specific application.

MCF^TM Flange Multiplexers

The basic goal of the multiplexer is to cost-effectively increase the number of ports available to interface the vacuum system.

Examples of Flange Multiplexers available from Kimball Physics.

Kimball Physics multiplexers have evolved since their original introduction (not patented) in 1983, to now include:

• rigid unitary stainless steel 316L precision CNC construction with reduction in the number of welds from eight to only one (the rotatable flange)
• the ability to use arbitrary bolt lengths (two sets of bolt holes, either threaded or clear provide user flexibility in the mode of attachment)
• inclusion of internal mounting annular grooves (Grabber Grooves) on the 2.75” CF port for internal mounting capability
• better ultra-high vacuum (UHV) cleanliness

 

The bolt ring is confined such that it cannot slide axially back from the sealing surface. Thus, the 2.75” CF sealing surface is not exposed to potential damage (as is the normal with ordinary rotatable flanges). These design features are included in all our multiplexer designs.

Useable interior space has been greatly increased over previous designs. Each 2.75” CF sealing surface has one pair of   Grabber Grooves for internal mounting capability.

Our most recent design, the MCF275-FlgMplxr-Cr1X5, includes a rotatable 2.75” CF (C) base port, with five (5) secondary sub-mini 0.95” CF ports to enable an increase from one to five ports.  The 0.95” CF (X) ports are compatible with Kimball Physics sub-miniature feedthroughs, flanges, and Viewports.

Flange Multiplexer MCF275-FlgMlplxr-Cr1X5 with 2.75” (C) CF rotatable base and five (5) 0.95” (X) CF secondary ports.

Our other MCF^TM multiplexers are based on a 2.75” (C) CF rotatable base that then may include various combinations of additional 2.75” CF ports and multiple 1.33” (A) CF secondary ports.

The 2.75” CF ports will also have internal mounting channels or grabber grooves that enable use of our extensive system for internal mounting of your apparatus, device or interfacing to our eV Part System that provides a diverse toolkit for concept prototyping and making custom mounting fixtures for your devices.

In the tables below, we provide more details about our various flange multiplexer components.

Multi-CF^TM Feedthrough Flanges:  Sub-Mini 0.95” CF

Kimball Physics Multi-CF^TM 0.95” Sub-mini UHV Flange Feedthroughs enable reliable high voltage and high current electrical connection to your apparatus inside the vacuum chamber or instrument housing.

The 0.95” CF flange is precision CNC fabricated from 316L stainless steel with options for various pin materials (Cu, Moly) and pin numbers (1, 2, 4), with a BNC and SMA connection also an option.

Pin diameter and spacing allow for high voltage and current capabilities (5kV and 55 Amps with the single copper pin and 2kV and 8.5 Amps with the two (2) and four (4) pin Moly connectors).  The BNC connector option allows up to 500 V and 3 Amps.

All Feedthroughs are UHV compatible with Bakeout temperatures up to 450^oC.

 

 

Multi-CF^TM UHV Flange Adapters:  2.75” to 0.95” CF Ports

The MCF275-FlgAdptr-C1X2 and MCF275-FlgAdptr-C1X3 Flange Adapters enable a single 2.75” CF port to provide either two (2) or three (3) 0.95” CF sub-miniature ports.   The flange adapters also provide an external outside diameter OD channel that can be used for external mounting.

The flange adapters are precision CNC fabricated from a single piece of stainless steel and are UHV compatible.  The axis of the sub-mini ports is slightly angled radially outward to provide more clearance for any attachments, such as electrical connectors to our 0.95” CF sub-mini feedthroughs.

 

Flange Adapters MCF275-FlgAdptr-C1X3 and MCF275-FlgAdptr-C1X2 (left and right) with 2.75” CF base and with either three or two 0.95” CF sub-mini ports.

 

Multi-CF^TM UHV Flange Adapters: 2.75” to 1.33” CF Ports

The MCF275-FlgAdptr-C1A1 Flange Adapter enables a single 2.75” CF port to be converted to a 1.33” CF port.   The flange adapter also provides an external channel that can be used for external mounting.  The 2.75” CF flange includes alternating clear and tapped holes (1/4-28 bolts) with annular grabber grooves along the port bore to enable use of Kimball Physics internal mounting clamps and eV Parts.

The 1.33” CF port has twelve (12) tapped holes that accept #8-32 bolts with a depth of 0.24”. No annular grabber grooves are present.

The flange adapters are precision CNC fabricated from a single piece of stainless steel and are UHV compatible.

Flange Adapter MCF275-FlgAdptr-C1A1

 

Multi-CF^TM UHV Sub-Mini Flanges:

0.95” CF Port Flange Extensions

Kimball Physics has several variations of Multi-CF^TM 0.95” Sub-Mini Flanges, including various lengths, combinations of clear and tapped holes, and the option to weld cylindrical eV Parts components to the flanges with a weldlip option.

These flanges are precision fabricated from 316L stainless steel.  Please refer to the table below for the various options available.

Sub-Mini Flange Extension : MCF095-FlgExt-X1/ Xc1-L1500

Multi-CF^TM UHV Sub-Mini and Mini Flanges:

0.95” and 1.33” CF Port Flange Blanks and Thin Flanges

The Kimball Physics Multi-CF^TM 0.95” Sub-Mini UHV Flange Blanks can be used to terminate (seal off) a CF port.  They have one CF sealing surface.

The 1.33” Mini UHV Thin Flanges can be used to seal a CF port, but with sealing surfaces on both sides, can optionally provide structure within the port diameter for creating custom apertures or mounting additional experimental apparatus on this metallic infrastructure.

Please refer to the table below for addition information.

Sub-Mini 0.95” CF Flanges, Flange Blank

 

Multi-CF^TM Viewport Flanges:

Sub-Mini 0.95” CF and Mini 2.75” CF

The Kimball Physics Multi-CF^TM 0.95” Sub-mini UHV Flange Viewport MCF095-SapphVP-X1 enables visual observation and measurement (e.g., pyrometer) inside the vacuum chamber or instrument housing.

The flange is precision CNC fabricated from 316L stainless steel, with the optical window for the 0.95” CF Viewport made from UV Grade Sapphire.   It has twelve (12) #4-40 alternating tapped and clear holes.

The larger 2.75” CF MCF275-MtgFlg-C1VP Mounting Flange Viewport is CNC precision machined from stainless steel with a Corning Type 7056 glass.  It also includes an outside diameter OD mounting groove for external mounting brackets. The flange has six (6) clear holes to accept 1/4-28 bolts for mounting to 2.75” CF flanges. Grabber grooves are not available on viewports.

Note: Caution should be used when handling viewports as they are susceptible to scratching and weak under stress points.

The Viewports are UHV compatible with Bakeout temperatures up to 450^oC, with a bake-out rate ramp rate of 20^oC per minute max.

Viewport Sub-Mini 0.95” CF Flange: MCF095-MtgFlg-X1VP

Viewport 2.75” CF Mounting Flange :MCF275-MtgFlg-C1VP

 

Summary

Kimball Physics Miniature (Mini) and Sub-Miniature (Sub-Mini) Multi-CF^TM UHV Vacuum System Components bring unique and important advantages to your research and development projects and commercial products.

Dimensioned drawings, for most of the parts presented, are available on the Kimball Physics website to further assist you in selecting your best solution. References are also provided below for additional documentation.

3D CAD Model STEP files are also available for most products presented and can be accessed from the Kimball Physics website.  These models add an additional resource to planning your system, enabling you to virtually assemble and evaluate the various design options in your CAD Software.

To LEARN more about External and Internal Mounting (Grrove Grabbers) Systems, please visit External Mounting, Internal Mounting 

To LEARN more about our eV Parts  Modular Components for Vacuum and Electron/Ion Beam System Prototyping and Apparatus, please visit our eV Parts overview in the Learning Center.

Please reach out to Kimball Physics with any questions or to speak with our engineers and physicists about custom designs and applications.

 

References

For more information about Multi-Port CF (MCF^TM) Vacuum Chambers and Accessories, visit our website at:  MCF^TM Vacuum Chambers

Other References (PDF)

Multi-CF^TM UHV Vacuum Chambers OVERVIEW

Multi-CF^TM Fittings Flange Multiplexers

Multi-CF^TM Thin Flanges

Multi-CF^TM Flange Adapters

Multi-CF^TM Fittings Groove Grabbers (Internal Mounting System)

Multi-CF^TM External Mounting System Overview

 

Notes:

1. Cautions for Multi-CF^TM Chambers

-Silver Plated Bolts or Equivalent Lubrication must be used.

-Please measure the hole depth and other flange / copper ring /part thicknesses

-Choose a correct bolt length such that the bolt doesn’t bottom in the tapped hole

prior to tightening the structure.

2. Specifications Subject to Change Without Notice.
3. Images are not to scale unless noted.
4. DE Altobelli 03/11/2024

Document MCF_Mini_SubMini_Overview_2025_0818

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