Sprecher der ceramitec conference

Auf der ceramitec conference wurden unter anderem folgende Sprecher und Themen vorgestellt. Bitte beachten Sie, dass das gesamte Programm in Englisch gehalten wurde.

Teilnehmerliste der ceramitec conference

Dr. Werner Bauer, Karlsruhe Institute of Technology (KIT)

Bidl von Dr. Werner Bauer, KIT

"Features of Powder Technology for the Production of Lithium-Ion Batteries"

Lithium-ion batteries (LIB) are an indispensable energy storage unit in many portable electronic and electrical devices. The presentation outlines the similarities and differences between classic tape casting and the production of electrodes for lithium ion batteries. It shows technological challenges and the specific impact of the materials on the battery process technology, and gives an outlook on new developments.

Dr. Mirna Bechelany, SAFRAN Group

Mirna Bechelany

"Additive Manufacturing Ceramic Casting Cores: Opportunitites and Challenges"

Current high pressure turbine blades for aero-engines work under extremely severe conditions, including combustion gas temperatures above the melting point of single-crystal (SX) superalloys, corrosive/oxidizing environments and very demanding mechanical efforts, especially concerning creep and fatigue. The main features that allow the blades to survive under these conditions are: the Nickel-based SX superalloys, the cooling circuit within the airfoil and the insulating thermal barrier coating (TBC). SX blades are produced in investment casting in the so called Bridgman process and require the use of complex ceramic cores, which are conventionally produced by ceramic injection molding (CIM).

Future aero-engines require even higher turbine entry temperatures (TET) in the order of +250K to be able to achieve the target reductions in CO2 and NOx emissions (75% and 90% respectively compared to year 2000 values) and corresponding fuel consumption defined by the Advisory Council for Aeronautics Research in Europe (ACARE) Flypath 2050, as well as to increase maintenance intervals, airfoil lifetime and recycling capability, due to the use of scarce materials and costly production processes. As the cooling circuit is a major driving force for achieving these goals and cavity design become more and more complex, the ceramic cores needed in the production process become more and more complex and include multiple walls solution in order to achieve the required performance, making CIM obsolete.

To overcome these limitations, rapid prototyping of ceramic cores was developed. The AM ceramic material show properties that meet the requirements of directional solidification and single crystal investment casting process. Wax patterns were injected to check the ability of AM cores to withstand the wax injection step and first cast components have been successfully produced. The casting parameters were trialed to give the maximum yield without performing any serious modifications. However, there are still some significant challenges that AM ceramic cores is facing and has to resolve such as an insufficient final strength of parts and dimensional integrity of the AM cores.

Alban Bunjaku, EIRICH

Bild von Alban Bunjaku

"Unexpected Opportunities for New Technical Ceramic Materials with EIRICH Intensive Mixers"

Dipl. Ing. Alban Bunjaku received his Diploma in ceramic material engineering in 2014. He worked as process engineer in the Test Center of Maschinenfabrik Gustav Eirich GmbH & Co KG. In this function, Alban Bunjaku was mainly responsible for customer tests and startups of machines and production plants. Since September 2018, he is in charge of ceramic applications as business unit manager and is the central contact person at EIRICH regarding ceramics – worldwide.

Dr. Blumm, Managin Director, NETZSCH Gerätebau GmbH

Dr. Blumm

"Digital transformation in the ceramic industry - A virtual view into the sintering process by thermokinetic simulation"

How to speed-up your sintering process up to 60% and reduce costs by reducing the number of test firesand reducing energy consumption.

Dror Danai, XJet Chief Business Officer

Dror Danai

The Use of Ceramics AM in Preventing Breast Cancer

More than 500,000 people die from breast cancer each year. A new system from the US-based Marvel Medtech offers a completely new approach to defeating this vicious cancer. The company’s new development of a robotic intervention guidance system will allow to freeze and destroy the most dangerous tiny breast cancer tumors immediately upon finding them during breast MRI scans. In this presentation, Mr. Danai will explain how Marvel Medtech can only produce the complex ceramic probe required for this unique life-saving system with ceramic additive manufacturing and specifically with XJet NanoParticle Jetting technology.

How XJet ceramic 3D printing will help 5G become the wireless revolution we’ve been promised

The XJet Carmel 1400 AM System, using NanoParticle Jetting™ (NPJ) technology, solves a crucial problem in the roll-out of the 5G network. In comparison to 4G/3G, 5G signals deliver data significantly faster, however they are more sensitive to objects and inference, requiring a vast increase in the number of antennas to solve the issue. Existing antenna technology is simply too expensive to enable the successful scaling up of infrastructure required by 5G.

The use of ceramic for creating a Passive Beam Steering antenna - a small, lightweight, cost-effective 5G antenna could be a real game-changer for this issue.

Producing the geometrically complex lens of the Passive Beam Steering antenna in Zirconia was not previously possible., as the Zirconia, like other ceramics, is very hard to machine. Therefore, traditional manufacturing technologies couldn’t create the super small structures, smooth surfaces and accuracy required.

The ability that additive manufacturing brings in general and XJet NanoParticle Jetting technology in specific to create complex geometries opens the possibility to create this antenna a reality. With Xjet

achieving both the material characteristics and the geometric properties essential to creation of the antenna became possible.

Guillaume De Calan, NANOE

Guillaume De Calan

Following its strategy to develop new raw materials for ceramic 3D printing, Nanoe has launched in 2018 Zetamix®, a line of filament for Ceramic Filament Manufacting (CFM). Zetamix is a filament constituted of a polymer matrix and a ceramic powder, which can be used in any FDM 3D printer. The 3D printed shape is afterwards debinded and sintered in the same processes as Ceramic Injection Molding. Available material includes alumina, zirconia, ZTA, black zirconia and stainless steel 316L.

Filament 3D printing is a technology which uses a thermoplastic filament as a raw material. This filament is pushed through a heated nozzle, which will deposit the melted material layer by layer. FDM is the most widely spread method of 3D printing in the world, with more than 1 million machines already installed, and a new 400 000 machine sold just in 2017. Zetamix filaments are designed to be compatible with all these printers, with little or no adaptation needed.

This new technology for ceramic 3D printing has a few key advantages which should make it complementary to other processes. Among the key features:

- Low cost investment, desktop machines

- Wide range of materials possible (on top of our standard materials, SiC, Si3N4, WC-Co, Silica and other are in development)

- Fully dense materials

- Possibility to print closed porosity, no washing of the part needed

- Fast prints

- Multi material possibility

- Possibility to print fiber reinforced ceramics

After one year of commercialization, main applications for this technology are prototyping, R&D and tooling.

After introducing our technology and giving a few results of printing quality and mechanical strength, our presentation will focus on toolings, and especially on wear and heat resistant tooling applications. We will give examples of such applications and demonstrate the interest both in design and cost this kind of technology can bring.

Holger Friedrich, Ceramics Group at Fraunhofer-Center HTL

Holger Friedrich

"Optimization of Heat Treatment Processes for AM / PM Products"

The Fraunhofer-Center for High Temperature Materials HTL is a materials and process oriented institution for applied research. We design energy-efficient heating processes with respect to productivity, energy consumption and product quality. One current focus is set on powder metallurgical materials and processes, e.g. technical ceramics or 3D-printing using binder jetting or slurry based methods.

Carl Fruth, CEO, FIT AG

Carl Fruth

"Driving the future: New product solutions by ceramic parts from additive manufacturing"

In the case of ceramic printing, radical innovation has meant to overturn 30,000 years of ceramic production techniques by upgrading them with state-of-the-art 3D printing and materials technology. Our mission is to turn a ceramic designers’ ambitious intent into reality – on industrial scale. When 3D printing of ceramic material is boosted with traditional ceramic firing and glazing arts, this leads to objects of unrivaled beauty, design innovation, and functionality. 3D printed ceramics is truly at the intersection of engineering and art and responds to the current trend of individualization. By providing luxury ceramic tiles and exclusive home décor, the most innovative manufacturing technology can find its way to modern homes. Additive design products stand out by their freedom of geometry and by structures rich in contrast between shape and material. The tool-free technology allows for production ranging from lot size one to mass customization. The service is a game-changing option for architects and interior designers, artists and product designers, as well as tableware manufacturers.

Thomas Gradl, EOS

Thomas Gradl, EOS

“Opportunities and challenges for the implementation of additive manufacturing (3D Printing) in the manufacturing industry”

The first 3D printing systems reached the market more than 30 years ago and companies in industries such as aerospace, automotive and medical quickly adopted this new technology.

However, in the vast majority of cases, the use of 3D printing (additive manufacturing) has not been transferred from the R & D departments and from the production of prototypes to the supply chain and mass production.

In recent years the technology has made great advances and systems, processes and materials are increasingly adapted to the specific demands of a various industrial sectors. Additive manufacturing is the digital technology "par excellence", its role within Industry 4.0 and the digital factory is fundamental.

However, despite continuous positive forecasts and predicted growth scenarios, only a rather limited number of applications has taken full advantage of the capacity of Additive Manufacturing to create innovative and even disruptive solutions, and even fewer have managed to cross the chasm into true serial production.

Many companies struggle to identify how AM can benefit their business, they cite a lack of AM expertise in-house as a main barrier preventing them from fully embracing the technology. AM transformation is less about technology but much more about people.

Recognizing the general need for education, guidance and consulting, EOS established in 2014 it’s Additive Minds unit, dedicated to support companies along their AM journey. Based on the experience of more than 300 implementation projects worldwide Additive Minds has identified key phases and barrier companies need to master along their AM transformation.

Carlos A. Grande, SINTEF

Carlos A. Grande

"New chromatographic substrates for separation of bio-pharmaceuticals"

The main advantage of 3D printing is the production of customized shapes that are not possible or that is very complicated to produce with other techniques. A technique like 3D printing allows the production of structured adsorbents that can reduce the pressure drop in chromatography processes. This means that we only use 3D printing because it provides a real advantage.
We have developed a mathematical design technique that allows new modes of interplay between mass transfer and fluid mixing (momentum transfer).

Jon Goldsby, National Aeronautics and Space Administration

Jon Goldsby

"Evaluation studies of solid oxide-based fuel cells for light-weight electrical power in aviation: Concepts and opportunities for the application of additive manufacturing"

Currently NASA is investigating the feasibility of hybrid-electric, solid oxide fuel cell power (SOFC) systems for generating electrical power for airborne propulsion and secondary/auxiliary power. As part of this project, researchers are investigating the performance of SOFC hardware in aviation-like environments, to establish the barriers, and potential suitability, of this technology. Immediate findings indicate the unsuitability of current SOFC stack architectures with regards to ease of manufacture, specific energy, as well as environmental and mechanical durability. One possible solution is to create light-weight high specific energy density solid oxide fuel cells. The possibility may be achievable by the use of modern processing techniques such as additive manufacturing. Here I discuss the use additive manufacturing to fabricate ceramic anode, electrolytes, and cathode cells supported on various metal foams with predicted performance based upon variable porosities.

Richard Gulotty, Honeywell Aerospace

Richard Gulotty

"Design and synthesis of C-C composite materials for aircraft brakes"

The aircraft brake disc design requires stable friction and wear performance during and after repeated high energy stops. Stability depends on the friction material maintaining its mechanical properties at the high temperatures that develop during and after repeated high energy stops. Thus, it is critical to performance that the aircraft brake discs absorb and dissipate the heat that is generated from friction and provide a path for heat to flow away from the friction surfaces. C-C composites meet the design requirements for the aircraft brake material application. The properties of C-C composite materials and performance in the aircraft brake application depend on materials structures at multiple length scales. The interface of the fiber with the matrix, crystallinity of the fiber and matrix, and effectiveness of anti-oxidant systems are process dependent and are critical to C-C composite performance in the aircraft brake application. The synthesis of C-C composite aircraft brake material typically includes preform densification, heat treatment, and anti-oxidant coating.

Iris Heibel, CERIX– grow platform GmbH

Iris Heibel

Challenges for industrialization of additive manufacturing of oxide ceramics – Insights from an user

CERIX – A Bosch Company has used the lithography – based ceramic manufacturing process (LCM) since 2014. First, the idea was to use this technology to accelerate projects for our core technology ceramic injection molding. Bosch’s goal is to produce high quality series products. When we introduce a new technology, it must have the capability for mass production. Therefore we carried out a machine capability study according to Bosch automotive standards. Depending on the market segment, an additional validation process is often requested.

Since our experience with the stereolithography ceramic additive manufacturing process began, many challenges have been solved based on this study and more opportunities are arising. Last year additional equipment using a larger platform was installed to fulfill the market requirements. Today we also run the equipment for series production.

We will present the principles of this study and some results about the best practices.

Cathleen Hoel, Senior Scientist - Ceramics

Cathleen Hoel

"Practical Considerations for Ceramic Additive Manufacturing from Conception to Production"

This presentation is for anyone who wants to bring the benefits of additively manufactured ceramics to their products and customers. We will look at partnering with designers, how to identify viable business opportunities, and what challenges need to be addressed for scaling up to production levels.

Aitor Hornés, Research Scientist, IREC

Aitor Hornés

Multi-material 3D Printing of Technical Ceramics for the Industrial Fabrication of Solid Oxide Fuel Cells (SOFCs)

Solid Oxide Fuel Cells are galvanic devices able to efficiently generate power from a gas fuel. Their architecture consists of stacking functional ceramic materials in a layer-by-layer fashion. Conventional SOFC fabrication includes plenty of complex processes, such as: tape casting, screen printing, shaping, and several high-temperature thermal treatments for fabricating single repetition units (s.r.u.), i.e. anode-electrolyte-cathode sandwich. Afterwards, stacking of these single cells is generally accomplished manually. In economic terms, the manufacturing process is expensive and time-consuming, leading to high capital cost, low flexibility and long time-to-market.

The Cell3Ditor EU project (www.cell3ditor.eu) aims at developing a 3D printing process for mass manufacturing of all-ceramic SOFC stacks. Within the project a multi-material 3D printer has been developed to enable mass production of the whole SOFC stacks in a single printing step. This innovative approach will allow avoiding joints and sealing elements, reducing the weak points of the stacks whereas increasing their durability. This printer combines stereolithography (SLA) and micro-extrusion printing technologies in a single machine for a sequential application of different materials during the printing process. An additional breakthrough of Cell3Ditor project consists in the implementation of a single-step sintering stage which will provide a striking cost reduction.

Within the project 3D printing fabrication of 3YSZ as well as 8YSZ electrolytes have been attained, showing the expected behavior in terms of mechanical and electrochemical properties even if relatively low sintering temperature is used (1300°C). Moreover, symmetrical SOFC button cells have been printed showing significant performances as well as good morphological properties. Currently, the activities are focused on the fabrication of the first fully 3D printed SOFC device.

Dr. Kambiz Kalantari, Lucideon

Bild von Kambiz Kalantari

“Adopting Disruptive Technologies - The case of Ceramic Additive Manufacturing”

The presentation will focus on Additive Manufacturing (AM) as a new disruptive technology in ceramics manufacturing. Using examples the presentation will demonstrate a high level review of Ceramic additive manufacturing as a forming technique. It will also include a discussion of how the technique can act as a game changer in the ceramic manufacturing process. Consequently, the presentation proposes criteria that manufacturers should consider before making the decision to switch to additive manufacturing.

Christian Kalupka, Fraunhofer Institute for Laser Technology ILT

Christian Kalupka

"Laser Processing of Ceramics: Technologies for Advanced Applications"

In recent years, materials processing with laser radiation has evolved to a key technology for industrial applications due to its unique properties for a wide range of different materials in dependency on the applied laser parameters.
In this contribution, we give an overview of several laser technologies for processing ceramics for advanced applications.

Prof. Dr. Frank Kern, IFKB - University of Stuttgart

Bild von Apl. Prof. Dr. Frank Kern

"Laser induced direct metallization – a new process to produce 3D ceramic molded interconnect devices"

Molded Interconnect devices have become the state-of-the-art when it is required to integrate microelectronic circuits into the structural part of a complex shaped polymer component. For new more damnding applications ceramics promise higher strength, stiffness and especially thermal stability.

Linda Klopsch, DLR

Linda Klopsch

„Space and aviation engines made of black ceramics“

Dr. Nadja Kratz, Forschungsinstitut für Anorganische Werkstoffe -Glas/Keramik- GmbH

Dr. Nadja Kratz

"Trends and perspectives in the development of optical and luminescent ceramics: a shining path into the future"

It is now well known that ceramics can not only be opaque but also translucent. But that's not all - ceramics can also play an active role in the interaction with light. Innovative materials are used that have not yet played a major role in the ceramic world. Rare earth dopants require special host lattices. New material combinations make it possible to expand the range of applications for optical and luminescent ceramics. Applications in lighting technology, such as ceramic converters for solid-state lighting, are a prime example and enable ceramics to enter a wide range of industries. Dielectric materials can also have electro-optical properties. Nd:YAG ceramics, which are used in solid-state lasers, can also be understood as active opto-ceramics. These are just a few examples. This talk gives an insight into current developments and applications of optical and luminescent ceramics and shows perspectives in the development of this special ceramic class.

Ass. Prof. Dipl.-Ing. Dr. Tanja Lube, Montanuniversität Leoben (MUL) – Department of Materials Science, Lehrstuhl für Struktur- und Funktionskeramik

Tanja Lube

"Strength of AM Ceramics: characteristic behaviour, isotropy and testing"

The strength of ceramic components and specimens is governed by specific inhomogeneities which are introduced during processing. This principle is also valid for additive manufactured components.

A specific aspect of the strength of AM ceramic components and specimens is the building direction. For example, the interface between adjacent layers may have properties that deviate from the properties of the layers themselves. In a prismatic bar as usually used for strength testing of ceramics the layers may be oriented parallel to each of the specimens faces. During flexural strength testing the applied stress then acts normal or parallel to the interfaces. This enables an investigation of properties in relation to the building direction.

In this contribution we present mechanical properties obtained on specimens from additive manufactured alumina components. Specimens tested in different orientations with respect to the building direction are investigated. The relation between applied stress direction, strength and building direction is presented. It is shown that specific inhomogeneities are responsible for failure. Depending on the testing direction and testing conditions these specific features may be identified or remain hidden.

Understanding the strength behaviour is thus an essential tool for additive manufacturing of components: knowledge of the location and characteristics of the weak zones is essential to optimize the manufacturing process and has to be taken into account when designing components.

Dr. Advenit Makaya, European Space Research and Technology Centre of the European Space Agency

Advenit Makaya

"Additive Manufacturing for Space Applications: Developments at the European Space Agency"

Dr. Advenit Makaya is an Advanced Manufacturing Engineer at the European Space Research and Technology Centre of the European Space Agency. He supports the development of promising advanced materials and processes for space applications, in various fields which include surface treatments, joining technologies, additive manufacturing, advanced polymers and in-situ resource utilisation.

Dr Alan McLelland, VP-Technology, Technical Ceramics – Morgan Advanced Materials

Dr Alan McLelland

"Additive Manufacturing of Ceramics: An Industrial Perspective"

Morgan have been developing additive manufacturing of technical ceramics, for investment casting cores and dense ceramic applications, for around four years and progressed to the position of commercial viability. In this presentation we will explore the process advantages including the benefits offered by the released freedom in design which allows highly complex designs, including those beyond current manufacturing pathways, to be realised.

Dieter Nikolay, WZR ceramic solutions GmbH

Dieter Nikolay

"Production of ceramic parts by Additive Manufacturing"

The term "additive manufacturing" (AM) covers a range of different processes that are increasingly being used in the ceramic industry. Within this contribution relevant commercial AM processes for the industrial production of ceramic parts are presented.

The focus will be on the 3 most relevant AM processes to produce ceramic parts: vat photopolymerisation (VPP), binder jetting (BJ) and material extrusion (MEX). These three processes - others are under development - enable the production of ceramic components in a very wide spectrum. Each process has advantages - but also limiting factors. This presentation provides the user guidelines for the selection of suitable technologies and the economic criteria to be considered.

Ph.D. Ismail Ozgur Ozer, MagSpin Inc.

Ozgur Ozer

"Transparent Ceramics for Durable Consumer Products"

MagSpin Inc. produces transparent ceramics for civil applications requiring high durability such as screens and cases for watches, smart phones and wearable technology products. Besides technical aspects, esthetic value is also a main concern in such durable consumer applications. Our engineering approaches create new designs to produce more appealing products. For instance; we control darkening, which is one of the main problems during manufacturing of transparent ceramics, by controlling the oxygen vacancy concentration to achieve a black tint or customized transparency. Moreover, we produce transparent ceramics with embedded designs by introducing scattering and/or absorption sites into the microstructure. On the more technical side; MagSpin produces functionally graded transparent screens where sides and corners are extra toughened, which are the most vulnerable parts to impact. In this talk, we would like to present these approaches, which enables to extend the applications of this rewarding material in consumer products market.

Dr Richard Padbury, Senior Technology Consultant, Lucideon

Bild von Dr Richard Padbury

"Data-driven approaches to material and process development: A new tool for the material science field"

Lucideon, and its partners, are focused on the development of data-driven services to support multiple segments involved in technical ceramics and advanced manufacturing processes. During the presentation, the data science toolbox will be introduced to highlight tradeoffs in explanatory and predictive power between the emerging use of machine learning (ML) and artificial intelligence (AI) and more familiar techniques in statistics. Examples of how various companies, academic institutions and government organizations are using these techniques will be shared to demonstrate how the data-science tool box can be accessed and leveraged for specific challenges.

Prof. Heinz Redl, Ludwig Boltzmann Institute for Clinical and Experimental Traumatology

Prof. Heinz Redl

"3D ceramic printing for bone replacement strategies"

3D ceramic printing might represent a promising alternative to autologous bone grafting, which is considered the current gold standard for the treatment of partially weight bearing bone defects. For this application, (long term) biodegradable materials such as hydroxyapatite or permanent high performance ceramic materials such as zirconium oxide, are of interest. Important parameters beside mechanical properties are surface structure (micro/nano), porosity as well as the material resorption rate in vivo. To test the biocompatibility and osteoconductive properties, several in vitro and in vivo test systems are available, of which most are established at the LBI Trauma.

Acknowledgement: Partly supported by Vienna Business Agency grant “HOBBIT”.

Dipl.-Ing. Uwe Scheithauer, Fraunhofer IKTS Dresden

Uwe Scheithauer

"Current challenges in the additive manufacturing of ceramic components"

Additive Manufacturing (AM) technologies are tool-free production processes which increase the freedom for the component design and allow designing and constructing oriented to function instead to fabrication. Certainly, these new technologies create new challenges along the entire process chain, e.g.

- design of ceramic components and optimization using software tools,

- generation of CAD-data and manufacturing technology-specific optimization of the geometry,

- limited building space,

- thermal processing of components with various geometry and size,

- mechanical characterization of filigree structure components and consideration of AM-specific properties like the cascading surfaces resulting from the layer-wise manufacturing process,

- …

The presentation will address some of these challenges and current approaches to coping with them. Furthermore the actual demonstrators of running IKTS-projects concerning AM will be presented.

Josef Schweiger, Poliklinik für Zahnärztliche Prothetik der LMU München

Josef Schweiger

"AM in der Digitalen Zahnheilkunde – Möglichkeiten und Limitationen"

Die additive Fertigung (= Additive Manufacturing = AM = 3D-Druck) erfährt aktuell großes Interesse in der Zahnheilkunde. Noch ist allerdings bei vielen Indikationen nicht klar, ob die immensen Erwartungen an die einzelnen Fertigungstechnologien bereits erfüllt werden, oder ob es sich aktuell um Wunschvorstellungen und Zukunftsmusik handelt. Bei aller verständlichen Begeisterung für diese faszinierenden Technologien, sollten Zahnärzte und Zahntechniker achtsam sein, um keinen Trugschlüssen oder leeren Versprechungen aufzusitzen und eventuelle Fehlinvestitionen zu vermeiden. Zudem kann nicht allgemein von „dem 3D-Druck“ gesprochen werden. Vielmehr müssen Einzeltechnologien voneinander unterschieden werden und nach ihren Möglichkeiten, Limitation und daraus resultierenden Anwendungsgebieten differenziert werden. Besonders interessant erscheint die aktuelle Entwicklung im Bereich des Keramik-3D-Druckes. Zirkonoxid hat sich in den letzten zwei Jahrezehnten als „das Standardmaterial“ bei der Versorgung mit Kronen und Brücken erwiesen und hat die klassischen Edelmetall-Legierungen nahezu vom Markt verdrängt. Bisher wird Zirkonoxid mittels subtraktiver CNC-Technik verarbeitet. Kombiniert man dieses Material mit additiven Fertigungstechnologien, so sind ganz neue Versorgungsmöglichkeiten denkbar Die ersten Ergebnisse zu diesem Thema sind vielversprechend.

Cyril Triplet, Projects Manager Modeling, SGL Carbon GmbH

Cyril Triplet

"CFD Modeling for ceramic heat treatment process"

Industrial heat treatment processes for ceramic materials and glasses involve a fine balance: processing times have to be short to assure economic feasibility, while heating rates are limited to prevent defects. With these technological constraints, all process parameters have to be specified such that the entire volume of the treated parts undergoes the exact temperature profile required for the heat treatment process to be effective. But these thermal phenomena cannot be easily approximated since complex thermal convection and radiation effects take place in ovens. Moreover, the baking process takes time, making trial runs extremely expensive and time consuming. In order to achieve an efficient baking the CFD simulation (Computational Fluid Dynamics) allows us to quickly predict the ceramic temperature and also optimize the oven geometry and its functionnality with low costs.

The aim of this study is to predict with CFD simulation the temperature field in a baking oven for ceramic under thermal convection and thermal radiation effects. A new furnace design process was to be developed with a ‘first time right’ approach. The process parameter settings required to achieve an optimal temperature profile were to be identified for different arrangements of the parts in the furnace chamber. The model enabled a full visualization of the temperature distributions during the firing cycle. It was ensured that this firing cycle prevents hot spots during the heat treatment process that may lead to defects like cracks and chipped features.

The digital assessment in the design stage of the furnace significantly reduced investment risk. The concept was validated early on in the design phase and costly modifications and downtime was avoided. The test effort in the commissioning phase of the new equipment was reduced significantly such that the new equipment can reach full productivity shortly after installation.

Dr. Thomas Utschig, Heraeus Electronics

Dr. Thomas Utschig

Metal ceramic substrates for highly reliable power modules not only in electric vehicles

Metal ceramic substrates (MCS) typically consist of a stack of bottom and top copper sheets separated by a ceramic sheet. This ceramic sheet has three basic functions: 1) providing low CTE (coefficient of thermal expansion) close to the semiconductor die and at the same time confining the high CTE of copper, 2) electrically insulating the top copper sheet carrying electric power from the grounded bottom sheet, while 3) providing sufficient thermal conductivity for the lost heat to be dissipated.

The standard ceramic used in MCS is alumina (Al2O3), which mechanical properties allow bonding of copper sheets with thicknesses of 0.3mm. Al2O3 can be bonded to copper by a process called direct copper bonding (DCB), where copper oxide at the copper sheets’ surfaces forms a eutectic with copper to create a liquid phase binding to the Al2O3 surface by interphase formation. Applications for this material, offered by Heraeus Electronics as Condura®.classic, are mainly in the industry segment.

Mixing zirconia (ZrO2) in an Al2O3 matrix yields a so-called zirconia-toughened Al2O3 (ZTA) allowing thicker copper sheets of 0.4-0.5mm thickness in the DCB process, due to increased mechanical strength of the ceramic. Heraeus Electronics markets this material as Condura®.extra, for applications with higher reliability demands like in the automotive and renewable energy segments (e.g. inverters for solar parks).

A distinctively higher level of reliability can be achieved using silicon nitride (Si3N4) ceramics, offering a much higher numbers of thermal cycles combined with an outstanding mechanical robustness compared to Al2O3 based MCS. An active metal brazing (AMB) process is applied to attach copper sheets to Si3N4, typically using a silver-copper-tin (Ag-Cu-Sn) hard solder system doped with activator metals. The formed bond is so strong that copper sheet thicknesses of 1mm can be applied even to thin ceramic sheets. Outstanding thermal dissipation performance enable power modules with highest power densities and enable using the full potential of wide-bandgap semiconductors (SiC, GaN).

Heraeus Electronics’ Condura®.prime uses TSN-90 Si3N4 of Toshiba Materials and is aiming at applications of highest reliability demands, mainly in automotive, energy and traction segments (e.g. main inverters in electric vehicles, inverters in wind turbines, power modules for railway applications).

Driven by combination of best reliability and superior thermal conductivity Si3N4 MCS will have biggest growth in the future. New, silver-free bonding technologies are being developed. This does not only help to decrease the cost but also to reduce the risk of silver migration in aggressive environments. Silver-free bonding is especially interesting in high voltage applications and will be used not only with Si3N4 but also with Aluminum Nitride (AlN) ceramics.

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