AERODAYS 2011

LTCC: A packaging technology p g g gysuitable for high density integration and high temperature applicationsg p pp

AERODAYS 2011

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AERODAYS 2011Madrid, March the 31st 2011

CREAM Project AAT.2008.4.2.4-234119

Conor Slater, EPFLPaul Vassy, Sagem

AGENDAAGENDA

INTRODUCTION: CREAM context and objectivesP l V S CREAM C di tPaul Vassy, Sagem, CREAM Coordinator

LTCC Packaging technology presentationg g gy pConor Slater, EPFL, PhD

2AERODAYS 2011Madrid, March the 31st 2011 CREAM Project AAT.2008.4.2.4-234119

INTRODUCTIONINTRODUCTION

CREAM CONTEXT AND OBJECTIVES

Compact and Reliable Electronics for Actuators and Motorspwww.creamproject.eu

AcknowledgementThe research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013)

3AERODAYS 2011Madrid, March the 31st 2011 CREAM Project AAT.2008.4.2.4-234119

European Union Seventh Framework Programme (FP7/2007 2013) under grant agreement AAT.2008.4.2.4-234119 CREAM"

INTRODUCTION

CREAM: FP7 Program with 14 PartnersSept 2009 – Sept 2012

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INTRODUCTION

CONTEXT

ACARE 2020: Environment, lifecycle cost More Electrical Aircraft Replace hydraulics actuation by electrical actuation Several subsystems concerned: Flight control systems landing gear Several subsystems concerned: Flight control systems, landing gear

systems, fuel pumps for motor regulation, cabin pressurisation… Several architectures under study on research programs

• Power buses (HVDC or AC)• Power buses (HVDC or AC)• Control buses (control loops management)• Energy regeneration issues• Share of the control loops between equipments• Electronics in cabinets shared between several actuators / integrated EMA in harsh

environment

CREAM bj ti i t lid t t h l i bli th i t ti fCREAM objective is to validate technologies enabling the integration of a compact, reliable “all in one” actuator in harsh environment. The

demonstration is performed on a primary flight control actuator

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INTRODUCTIONInnovative Actuator Mechanism with high integration of motor, bearings  and roller screw developed by Sagem

Control electronics Power drive electronics

Control electronic technologies :• high temp substrate (LTCC,HTCC)• LT process nanoscale joining• high temp protections• SOI and asic integration

2.3

• SOI and asic integration

Power electronic technologies :• high temp substrate• LT process nanoscale joining• high temp integrated curent sensor

2.2

St t f th t G ti 2• Sic Power part State of the art Generation 2  Aileron actuator (2010)

Weight /vol  : 12.5 kg/ 6 l , Reliability 40000h, Temp 85°C

TRL6 Fli ht A320 fl i t t b h

Compact control and 

High temperature Reliability evaluation program research

2.4

TRL6: Flight proven on A320 flying test bench

3

Motor mass & volume reduction and temp increase

• higher density magnetic material• Motor power optimization• New motor concept (Variable reluctance)

Electronic motor and mechanism integration conceptFuture CREAM EMA technology  

Power drive electronic MCPM

2.1

6AERODAYS 2011Madrid, March the 31st 2011 CREAM Project AAT.2008.4.2.4-234119

Electronic, motor and mechanism  integration conceptfuture aileron actuator Target weight/vol  : 9 kg/ 4 l , reliability >50000h, Temp > 150°C

LTCC Technologygy Description of Control Module Description of Control Module Properties of LTCC LTCC manufacturing Process Design Rules Design Rules Packaging Technologies Conclusion

Conor Slater, EPFL

7AERODAYS 2011Madrid, March the 31st 2011 CREAM Project AAT.2008.4.2.4-234119

PhD

LTCC Technology

Description of Control Module

Control Module to Survive in Ambient Conditions (-65°C to 200°C)• Operational Lifetime of 100,000 hours

Substrate will need to mount a high number of components (500+) but the total power dissipation will be less than 10W

• Packaging technology will be required for:

● Passive components

● Mounting Silicon dies● Physical attachment● Thermal conduction● Electrical InterconnectsElectrical Interconnects

● Mounting Substrate to Baseplate

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LTCC Technology

Properties of LTCC

Good electrical characteristics• Low Dielectric Loss at high frequency

and high breakdown voltage

Good Thermal stability (450°C+)

Multilayer Technology• Possible to integrate Resistors,

Capacitors and Inductors

3-Dimensional Structures• Cavities and Channels, by means of unfilled cuts and sacrificial layers

Compatible with “Classic” Thick Film Technology (firing temperature <900°C)• Allows use of Pt, Au, Ag, Pd, Metallisations and Thick Film Resistors

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Allows use of Pt, Au, Ag, Pd, Metallisations and Thick Film Resistors

LTCC Technology

LTCC Manufacturing Process

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LTCC Technology

Design Rules

Variety of Thicknesses (…, 50 µm, 114 µm, 254 µm, …)

Dimensions of Thick Film Conductors and Resistors defined by Screen Dimensions of Thick Film Conductors and Resistors defined by Screen Printing Process

• Track width 200 µm

• Clearance 200 to 250 µm● Depending whether tracks are printed

simultaneously or in separate stepsy p p

• Via Diameter 300 µm

• Minimum Resistor Size 500x800 µmMinimum Resistor Size 500x800 µm

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LTCC Technology

Integrated Passives

LTCC allows passive components such as Resistors to be integrated into the substrate.

• At high temperatures the values of the resistors drift due diffusion of contact material by oxidation

● A barrier layer on the contacts can prevent diffusion allowing stability at 200°C1

● Embedding the resistors between LTCC layers● Embedding the resistors between LTCC layers or under an overglaze protects from oxidation and improves the stability of the Resistor2

● Thin film resistors have greater stability at high

[1] R Johannessen, F Oldervoll, F Strisland, and P Ohlckers. Performance of thin and thick film resistors exposed to high temperature and high pressure (200°C @ 1000 bar). In HITEN 2007, Oxford, UK, pages 678–682, 2007.[2] A Dziedzic L Golonka M Hrovat J Kita M Kosec and D Belavi Some remarks about relations between processing conditions and

temperature but are more expensive

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[2] A Dziedzic, L Golonka, M Hrovat, J Kita, M Kosec, and D Belavi. Some remarks about relations between processing conditions and microstructural, electrical as well as stability properties of ltcc resistors. In European Microelectronics and Packaging Symposium, Prague, Czech Republic, 2004.

LTCC Technology

Compatible Component Attach Methods (1)

Solders• CREAM > High Lead Solder (225 – 300°C)• Variety of Metallisations can be used with LTCC

Transient Liquid Phase (Diffusion Soldering)• Can be used with LTCC due to liquid phase

E hibit l lif ti t hi h t t 3• Exhibits long lifetime at high temperatures3

Silver Filled GlassDi tl tibl ith LTCC b t t• Directly compatible with LTCC substrate

• High Thermal Conductivity and strength4

[3] H.A. Mustain, W.D. Brown, and S.S. Ang. Transient liquid phase die attach for high-temperature silicon carbide power devices. Components

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g gand Packaging Technologies, IEEE Transactions on DOI - 10.1109/TCAPT.2010.2046901, 33(3):563–570, 2010.[4] R. Kisiel and Z. Szczepanski. Die-attachment solutions for sic power devices. Microelectronics Reliability, 49(6):627–629, 2009.

LTCC Technology

Compatible Component Attach Methods (2)

Polymers

• Polymers such as epoxies and silicones adhere well to LTCC

● Silicones and Epoxies stable in the 200-250°C range

● Polymers allow flexibility in CTE mismatch between the substrate and the baseplatey y p

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LTCC Technology

Wirebonds

Gold wire bonds work well on LTCC due to matching Metallisation

Aluminium wires more common Aluminium wires more common• Aluminium metallisations on LTCC problematic due to oxidation during firing

Aluminium to Silver results in Aluminium to Silver results in oxidation of intermetallic5

A li ti f Thi fil b i Application of Thin film barrier layer shows good performance6

[5] R. Kisiel and M. Guziewicz. High temperature applications of al wire connection to sic structures. In 31st International Spring Seminar on Electronics Technology, pages 264–268–, Warsaw Univ Technol, Inst Microelect & Optoelect, Warsaw, Poland, 2008.

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gy p g p[6] R. Johannessen, F. Oldervoll, and F. Strisland. High temperature reliability of aluminium wire-bonds to thin film, thick film and low temperature co-fired ceramic (ltcc) substrate metallization. Microelectronics Reliability, 48(10):1711–1719, 2008.

LTCC Technology

Conclusions

LTCC • Stable at temperature range for CREAM-EMA• High density of interconnects and routing possible• Integrated resistors show good stability at high temperature

Extensive range of packaging technologies compatible with LTCC• Allowing a variety of component configurations to be packaged

LTCC’s suitability for the control module is based on its flexibility• Easily structurable• Wide range of compatible materials

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INTRODUCTION

THANK YOU FOR YOUR ATTENTION

QUESTIONSQUESTIONS

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