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BIA-Brukerstyrt innovasjonsarena

Sensor Technology for Green and Safe Jet-Engines (STEGS)

Alternative title: Sensor Technology for Green and Safe Jet-Engines (STEGS)

Awarded: NOK 12.0 mill.

Project Number:

269672

Project Period:

2017 - 2020

Funding received from:

Organisation:

Memscap has the target to develop a new pressure sensor family for pressure measurements up till 70 bar. These pressure sensors shall be developed with the regard to the requirements set forth by the aerospace industry for motor control on Jet-engines, FADEC ( Full Authority Digital Engine Control). To face the stringent requirements for pollution from jet-engines and safety requirements, new technology must be used to a greater extent. When now the company wants to move towards the engine control market, it is necessary to provide pressure sensors up to 70 Bar. The existing technology the Company possesses has to be further developed. In the STEGS project, it has first of all been focus on how to manufacture sensors that can withstand far higher loads / forces (pressure) from the environment than the present technology can handle. The sensor family to be developed will be absolute pressure sensor. Memscap has thus focused on four work packages in the project. All pressure ranges, 5, 30 and 70 Bar sensor dices has be processed on SOI. Also, the SINTEF fusion-bonding process has also been developed further. The project has also brought forward a new design of the silicon support-die that supports the sensor die. By using simulations, a mechanical design that will isolate stress forces generated on support-die to the sensor die has been developed. It was also necessary to develop a good and solid process for soldering the die stack structure to the sensor capsule/header. At the final stage in the project, test results have shown a good bonding strength on Fusion bonding. The company will continue with expanded testing and qualification beyond in the project to ensure the best possible reliability and stress isolation from package assembly. This will be done in the new NRC granted project ( No.309362 ). In the project, the company has developed new sensor dies for higher pressure, 5 bar up till 70 bar absolute pressure with circular membranes. In collaboration with SINTEF, the project has come forward with design solutions that seems to be of satisfactory with respect to get good solutions to the design and processes for this new sensor family. In discussions with SINTEF, it was decided that SINTEF's new Fusion-boning process should be put forward for lamination of the sensor die to the support die. This has successfully been done, and this is also a much more preferred lamination process than the originally planned anodic-bonding process. The tasks in the project's work package 1 has been substantially expanded to ensure the best possible process optimization in the work package 2 where the sensor chip should be processed. This caused in the beginning that the actual sensor dies was some months delayed, but today, it shows that it was a good decision. SINTEF has successfully developed the Fusion-bonding process further with the sensor wafer and the support wafer. Three-layer "Cavity" fusion-bonded wafers have been laminated with very good results. The three stack wafer was thus moved further on to the processes for ion- implantation of both leads and piezo-resistive resistors and finally put forward for epi-layer passivation. All these processes where successfully achieved. Further, in the projects work Package 3, encapsulation of the sensor stack. Metal alloy for the soldering process has been defined but not fully qualified. There are some activities left to find the right supplier of equipment. It also remains more qualification and testing on whether the chosen alloy process will be of satisfactory with good enough strength. Also, the package design is established and is now provided by the subcontractor. Preliminary tests of encapsulated dummy sensors have been performed successfully, but in order to proceed, a proper equipment supplier must be determined. Some delay due to the COVID-19 situation. It has previously been mentioned that Fusion bonding and buried conductors have resulted in heavier activities in work packages 1 and 2 and therefore to some extent delayed the project. Those processes were not taken into account in the project planning, but came active early in the project phase. Both processes have successfully been achieved and after initial testing of few sensors, the project management team is quite pleased with the decision taken. The project can now put forward the sensor family to the next stage, the STEGS-2 project which will take the sensor family / technology to TRL-8 level.

The target for the STEGS project was to develop a new Pressure Sensor family in the range of 5 bar up to 70 bar for FADEC ( jet-engine control computers) applications. The project had to overcome the challenges of achieving the high performance of long term stability as well as a high degree of hermetically packaging. To achieve the performance of stability, it was decided to develop a wafer level fusion bonding on the silicon wafers as well as anodic bonding on the reference glass wafer. Both processes were successfully achieved in the project. Also, the target for an hermetically packaging by soldering the sensor stack into a header were successfully achieved together with an international partner, PINK in Germany. The outcome of the project will be the input for a new granted NRC project No.309362. The final results so far in the project, has also triggered an eager of potential customers like Honeywell and BAE systems to get samples for testing.

The primary target of STEGS is to make a significant contribution to a future green and safe air transport funded on creation of national values through a strong competence in using microsystem technology and manufacturing. STEGS targets to deliver best-in-class integrated transducer modules to the technical solution generally known as Full Authority Digital Engine Control (FADEC) for aircraft jet-engines. In this application, ultra high precision pressure sensors are the KEY for reduced fuel consumption; they enable optimized use of the engine that reduces wear over time, and they monitor the condition of the engine and give early warnings about potentially fatal failures. STEGS will place MEMSCAP in a good position in the aircraft industry value chain to provide cost-efficient transducer modules that are particularly robust in use, reliable in all kinds of weather conditions, have accuracy and long-term stability in the 100-ppm range, thereby answering exactly to the future needs of the avionics industry. A silicon-based microsystem technology platform for fabricating pressure sensors with best in class measurement accuracy and reliability will be the outcome of STEGS. The US companies AMETEK, BAE Systems, SpaceX and Nasa/JPL are pilot customers in the project and will all take part in testing the quality of the outcoming sensors. Estimated total opportunity for MEMSCAP to create national values by export of transducer modules is in the range 5700 mill. kr over a product lifetime of 20 years. STEGS is highly focused and partners in the project are MEMSCAP AS and SINTEF ICT. The general aspects of the microsystem technology platform from STEGS will also benefit the microtechnology industry in Norway as a whole and all customers of SINTEF ICT in the domains of enabling microsystem technologies, reliability physics and silicon wafer processing at MiNaLab.

Funding scheme:

BIA-Brukerstyrt innovasjonsarena