VTC in the Czech Republic
specialises in vacuum technology components 
ceramics, flanges, special parts, 
brazing, welding, plating, metalizing
VACUUM TECHNOLOGY will introduce innovations to you.



Vacuum is space that is devoid of matter. The word stems from the Latin adjective vacuus for "vacant" or "void". 

An approximation to such vacuum is a region with a gaseouspressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a perfect vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. The Latin term in vacuo is used to describe an object as being in what would otherwise be a vacuum.



has been part of Alumina Redwitz Holding
Our business unit LIKE creates innovations for you.






In vacuum technology, completely vacuum-tight seals are vital, coupled to the excellent  insulation offered by ceramics and high level of dielectric strength. LAPP Insulators Alumina offers a wide-ranging programme of standard vacuum feedthroughs to match your needs, whether that be controlling, measuring or directing energy. Alumina draws on long years of experience and high levels of know-how in this field. We are your most reliable partner for your special applications and requirements too – guaranteeing our customers quality, reproducibility and satisfaction.


Product capabilities

Alumina Systems offers a variety of conductive materials for the manufacture of vacuum feedthroughs such as non-magnetic copper (OFHC) or nickel. Feedthroughs are capable of working at temperatures of between -150°C and +450°C. By using high temperature braze, even higher operating temperatures of over 600°C can be achieved. Surface resistance of the glazed ceramic surface measured against a 5kV DC voltage exceeds 1x1012 ohms. Vacuum feedthroughs from Alumina are routinely tested to leak rates of 10-8 mbarL/s. On application we can test to 10-9 mbarL/s. The components’ electrical properties such as maximum voltage and current loading are measured in air; so considerably higher values apply under vacuum. Vacuum technology has been another application for FEM analysis at Alumina since 2013. This computer-aided design analysis offers our customers made-to-measure, intelligent solutions. The decisive advantage lies in reduced development times for the absolute optimum design at considerably lower cost, even at the prototype phase. Alumina develops components hand-in-glove with customers to series production launch, drawing on the considerable expertise of their in-house research and development department, “LIKE



Alongside standardised component ranges Alumina produces alternative solutions in ceramic-to-metal, carefully matched to individual customer concepts. To minimise the development period for new ceramic-to-metal components Alumina utilises the Finite Element Analysis development tool (FEM for short) to support new product design. Specially for the design of ceramic components, we have a state-of-the-art component break statistical predictive tool. This is capable of rapidly comparing component design variants so that the most robust mechanical design can be chosen before moving to the prototype build stage. Prototype quantities are minimised, resulting in cost savings and project development periods reduced by several weeks. In contrast, simulation testing requires one to two weeks.


Alumina develops components in tandem with their customers to series manufacture. We are also pleased to consider commissions from third parties. The costs for a simulation typically lie well below those of tooling for samples. Static and transient thermodynamic calculations are applied, while Alumina can draw on the resources of the group research team "LIKE" for magneto-electrical calculations.





Alumina ceramics

Alumina ceramics is characterised by its high mechanical strength, hardness, wear resistance, high insulation resistance, low dielectric losses, vacuum-tightness and chemical endurance. Alumina is used for highly stressed parts for applications in mechanical, electrical and chemical engineering, electronics, vacuum technologies, food industry and in the manufacture of grinding elements require a variety of grades. Major industrial applications: specials, rings, bushings, wire drawing dies, tubes, gauges, brazed joint metal-ceramic parts.


Metallized ceramics 

Metallized ceramic is a product that generally consists of a ceramic insulator and a metal conductive coating. The coating can be applied automatically or by hand. The item is then dried and fired at high temperatures in special furnaces. When the coating is applied it offers very little conductivity but after firing the coating is quite conductive. 



Invar, also known generically as FeNi36 (64FeNi in the US), is a nickel steel alloy notable for its uniquely low coefficient of thermal expansion (CTE or α). The name, Invar, comes from the word invariable, referring to its lack of expansion or contraction with temperature changes. FeNi42 (for example NILO alloy 42), has a nickel content of 42% and α ≈ 5.3 ppm/°C which matches that of silicon and therefore is widely used as lead frame material for electronic components, integrated circuits, etc. FeNiCo alloys—named Kovar or Dilver P—that have the same expansion behaviour as borosilicate glass, and because of that are used for optical parts in a wide range of temperatures and applications, such as satellites. 




E-shop for you.

As specialists in technical ceramics we supply a variety of standard and custom made solutions ranging from sintered alumina rings for vacuum, vacuum-tight joints, brazed insulators, bushings, metallised ceramic parts, to housings for power semiconductors, etc.

Please challenge us with your design and we will find a suitable solution. 



21/11/2017 14:06
Insulator 4020 - 75kV, ConFlat Voltage DC:                       >75kV Tube:...
21/08/2016 12:58
Voltage DC:                       >60kV Tube:          ...
20/10/2015 08:59
On 14.10.2015 we visited Vacuum Expo in Coventry to see the progress of the industry in the last few years. We came...
24/09/2015 08:04
                       Vacuum insulators consist of special ceramics...
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20/02/2015 15:12
  Vendor: LAPP Insulators Alumina s.r.o.     Insulator 4009 -...
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Alumina Systems s.r.o. Kladska 916/65
500 03 Hradec Kralove
Czech Republic
+420 603 828 173 jklejch@alumina.systems