Large Area Coaters
For over one and half decades, HHV has been expending considerable efforts towards the development of large area vacuum coating equipment, adopting the latest thin film deposition techniques in its large area coaters and offering economical solutions along with recipes to attain the exact properties on the large area optics for a wide range of applications globally.
Large area coater with thermal and EB gun evaporation
HHV commissioned a large telescopic mirror coater in the world's highest Astronomical Observatory in the Himalayas at 14,800feet (4,517 meters) above sea level in Hanle, India. It’s meant to coat a large telescopic mirror of a size 2.1m in diameter and a weight of 1.0 tonne. The telescope mirors coater has been integrated with a combination of thermal and electron beam (EB) gun deposition tools to deposit Aluminium and dielectric layers. It has been demonstrated for its performance and consistency of the equipment with large area and heavy substrates.
Large area coater with magnetron sputtering
The large area substrate coater with a magnetron sputtering with a downward sputtering deposition was installed in the western part of India, at an altitude of 1000 meter above MSL. It is meant to coat a concave shaped, 2.2m diameter telescopic mirror of weight 2500Kgs. It was a technological breakthrough for HHV in developing a large sized magnetrons suitable to deposit aluminium with high reflectivity.
Large area sputter coater with Whiffletree" substrate holding mechanism
This large areas thin film deposition system to coat with a surface accuracy of 1/16th of 550 nanometres with 20.0kW water cooled rectangular magnetron fixed with an Aluminium target of size 89 mm (W) x 2000 mm (L), and 6.00mm thickness. Its design and manufacturing capability was to position the 3.7 m diameter, 4500 Kg weight mirror, with a thickness of 12 mm on a kinematic support mechanism known as a “Whiffletree” which ensures no stress and a sag of large substrate during the coating process.
Appropriate masks were designed for the magnetron and a thickness uniformity of ± 3 % was obtained over the 3.7 m diameter substrate. The system has been installed at Devasthal, Nainital, at an altitude of 2500 meters above MSL.
Large area sputter coater to depost Silver /Aluminium coating on telescopic mirror with protective layer
This was done with three 20 kW water cooled Rectangular Magnetrons suitable for coating a telescope mirror of size 2.55 m in diameter and a weigh of 3000 Kg and was installed in the Caucasus mountain observatory of the Sternberg Astronomical Institute of the Moscow State University. The instalation required the development of the process recipe for the deposition of silicon-dioxide protected Aluminum/Silver Coatings. In this equipment, the Chromium and Silver/Aluminium were deposited by DC sputtering, and the Silicon-di-oxide is deposited by reactive sputtering using a Silicon target.
Robotized sputter coater for irregular, large area substrates
HHV designed and developed a large size coater with a magnetron fitted on a robotic arm for deposition of uniform, conductive and transparent coatings on substrates with complex geometry like the canopy / windshield of an aircraft which is made out of polymers.
As the magnetron cathode has to uniformly cover the total area of the complex shape of the canopy and the windshield maintained at all times a predetermined distance, a need of a robot controlled sputter coating facility has been conceptualized.
The coating scheme consists of a highly transparent, highly conductive film which is then covered with a protective overcoat.
Dual magnetron sputtering system
The uniqueness of the large-area dual-magnetron sputter coater developed by HHV is that it can sputter two materials in sequence on a clean 1 sqm surface, and has the facility to sweep from one end to the other, automatically stopping on reaching the programmed thickness.
The system has a chamber size of 1.5m x 2.5m and the entire process is controlled by a Human Machine Interface (HMI) unit.
Process gases and target materials can be chosen based on user requirements.
In-line Horizontal Magnetron
HHV has designed and developed an In-line Horizontal Magnetron sputtering system for commercial applications to handle substrate of size 1.0 m x 1.0 m. The multi-chambered DC magnetron system consists of entry and exit load lock chambers, isolation chambers and process chambers.
The substrate is introduced into the process system horizontally through specially designed vacuum compatible conveyor belts, which minimises the sagging effect. A substrate heating mechanism is provided with radiative heaters and reflectors to effectively concentrate the heat energy on to the substrate surfaces, which ensures the minimum loss of energy.
The sputtering cathodes are provided on the top of the process chambers and are easily accessible for changing the targets. The system has is designed to have the flexibility to increase the number of sputtering cathodes by adding chambers, which will increase the through put or number of layers if required.
The entire system, and the various processes involved is controlled using SCADA based control platform.
Engineering and process advancement with rotary magnetron
HHV developed of a vertical in-line coating system fitted with a rotary magnetron cathode source for a high throughput industrial production of TCO coated glass substrate of size 1.1m x 1.4m.
The vertical design ensures a reduced footprint and at the same time avoids debris from the magnetron shield or mask from reaching the substrate during the coating. In order to make the process more industry friendly, the system has been developed with a rotary magnetron sputter cathode.
The continuously rotating surface yields more usage of the target material, therefore leading to longer production runs. Rotary magnetron usage result in much higher target material utilization of > 80%. Secondly, since the part of the target that gets eroded keeps changing continuously, much higher power densities can be used as the target gets sufficient time to cool down during the rotation. Both these aspects make rotary magnetrons highly suitable for industrial production.
The system uses a frame-less glass holding mechanism which facilitates the entire area of the substrate to be coated. For this purpose, the equipment has been designed with a suitable tilt with respect to the vertical so that the glass directly rests onto the conveyor mechanism. Such a position is ideal for the handling of large glass substrates as it prevents any localized sagging. A thickness uniformity of within ± 2% is obtained for coatings on these large glass substrates.
The in-line vertical magnetron sputtering system is a highly flexible platform, which can be optimized for variety of applications such as Mirror Coatings, TCO Coatings, Architectural Glass Coatings, Beam splitters for 3D imagining, etc.