Posted: 29 July 2019
A Professor of Material Science at a Boston area leading university was introduced to Applied Thermal Control by Mantis Deposition Systems, who had supplied specialist bespoke Vacuum Deposition System.
The purpose built system is now installed in the University, having been designed from scratch. Due to the unusual and innovative nature of the system, ATC worked in conjunction with Mantis to create an optimised solution. At one stage there was a choice between using liquid nitrogen or a chiller, but ultimately the ATC K3 chiller was selected as it came with less of a burden on infrastructure.
The ATC chiller was selected due to the excellent performance specifications and the quality of pre-sales communication provided. ATC are proud to take time to understand our customers’ requirements, provide best advice and a suitable chiller for the customers’ needs. Our customers feedback that it feels a bespoke service and that they are not just picking the closest option from a catalogue.
Research work in the department includes using an established technique for growing very thin film for semiconductors. These are used in industry for making high speed devices such as, mobile phone antennas, radio transmitters and lasers but also used in research settings for exploring new materials, and new combinations of atoms.
The department tries to make ultra-thin films of very new materials; mainly sulphide and selenide semiconductors. These materials contain the elements sulphide and/or selenium. Their research focuses on trying to make new materials and new combinations of atoms by using Molecular Beam Epitaxy (MBE) technique.
MBE equipment is extremely bulky, with multiple modules and subsystems attached to it. An important part of the MBE system is the Cryo panels and Internal Cryo systems. The MBE is under very high vacuum at all times and it is important to maintain a good vacuum to keep as many gas vapours out as possible. Cold surfaces inside the chamber’s cold panels are called Cryo panels which maintain the temperature by recirculating Hexid heat exchange fluid. There are two sets of Cryo panels in the system that are both connected to the ATC chiller in parallel.
The ATC chiller improves the quality of the work the department carry out. Whilst without the chiller the group would still be able to make films, they would have frequent issues with contamination.
The Professor said of his experience: “ATC offered a high level of expertise and we found it easy to engage with ATC on what was required. They develop high end equipment for applications and it was easy to talk through details on this application and get good advice.
“Although it was a standard chiller which was ultimately specified I had confidence that our needs had been understood and applied to the solution provided.”
He went on to say, “I would gladly use ATC chillers again and would be happy to recommend ATC to my peers and colleagues.”
There was an unusual issue with the system in use. ATC Technical Manager Mitchell Howard and IES Technical, the local agent and representative worked with the customer to find a suitable solution.
The chiller and MBE system are located in different rooms, insulated lines for supply and return are built into the lab to connect the two rooms from ankle height to eight to ten feet high, from the ATC chiller which is located on the floor. The lines go through the divider between the two rooms and come back down to the system eight to ten feet of head on those lines. The customer encountered an issue when they switched the system off, the back pressure caused the fluid to leak out of the reservoir on the ATC chiller side.
ATC technical support worked with the University to locate the issue and provide the solution. ATC supplied a solenoid valve which was installed but this didn’t initially solve the issue. Mitchell Howard suggested a replacement for the reservoir, but instead of using a plastic reservoir with a screw cap, ATC designed and supplied a steel reservoir with a more secure closure, which resulted in the system working effectively.
They have found it very useful to their operation that the system be can heated. Ninety nine percent of the time the requirement is to chill the temperature but, when venting the system, they want it to be hot and drive off all the vapours that have condensed, this is a very convenient feature.
As the system is water cooled with building dust issues it is one less problem to worry about, as there is a construction company building right outside the windows creating a dust issue with the laboratory.
See more details on the K3 chiller here.