Tutorials on Systems Miniaturization

Luiz Otávio S. Ferreira - LNLS

November 28, 2001

Luiz Otávio S. Ferreira 2

Outline

• Introduction to Systems Miniaturization

• Microfabrication Technologies

• Microsystems Development and Packaging

• Microfabrication in Brazil

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Introduction to Systems Miniaturization

• Microsystems:– Sets of microdevices capable of

integrated sensing, analysis and actuation.

• Microdevices:– Microstructures capable of actuation, or

signal transduction, or chemical reaction, etc.

Ivo M. Raimundo Jr. IQ/UNICAMPMUSA2000Nobuo Oki

UNESP Ilha SolteiraMUSA2000

Luiz O.S. Ferreira LNLS

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Why Miniaturization?• Reduction on mass and size.• Integration with electronics.• Exploitation of new effects due to

small size.• Cost/performance advantages.• Improved reproducibility, accuracy

and reliability.• Redundancy and arrays.• Low power consumption.• Less material used for

manufacturing.• Avoiding of rare or aggressive to

environment material.• Easy disposal.

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Vocabulary

• USA– MEMS– Microelectromechanical Systems

• Europe– Micro Systems

Micro Systems Technology

• Asia– Mechatronics– Micromanufacturing

• Other names– Micromechanics– Nanotechnology– Microtechnology– Meso Systems

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Market Demands on Miniature Systems

• Environment

• Medicin Technology

• Information Technology

• Biotechnology

• Automotive

• Consumer electronics

• Projected sales for 2003:32 B$ (US$)

Source:

Solid State Technology, July 1999, pp. 63-65.

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Technological Possibilites - 1

• Microtechnology for electronics– Technologies developed or improved

on last 20 years:• Silicon crystal production.• Thin film technology.• Lithography and etching.• Modeling.• Characterization.

– Non electronic interations:• Springs, membranes, piezoresistive effect,

heaters, etc.

– Well developed material and technology: low cost if large scale production.

– Systems integration.

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Technological Possibilities - 2

• Full system approach– Technologies for

• Assembly

• Interconnection

• Housing

• System integration

– Bonding and joining• SMD, COB, TAB, DCA, Wire bonding,

Flip Chip

– Analysis of the interactions

– Reliability

– Performance and cost

– Volume

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Technology Adaptation

• Old technologies, from micro-electronics and from mechanics, are adapted for use on micro-systems integration.

• Some new steps must be developed.• Old materials are used on new ways:

different properties.• Only a whole system approach leads

to effective systems.• Numerical analysis of

interdependencies.

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Why Integration?

• Better shielding of weak electric signals from sensors.

• Individual sensor calibration on factory. Lower calibration cost.

• On board intelligence.

• Reduction of connection cables.

• Standard communication protocols.

• Save cost on extra electronics housing.

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How to Integrate?

• Monolithic Integration:– Very difficult and expensive.

– Very large scale of production.

– Large number of interconnects.

– Number of masks.

– Time of development.

– Yield.

– MCM

• Hybrid Integration:– In 1997, 8% of the pressure sensors and

12% of the accelerometers where monolithically integrated.

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Product Oriented Approach

• Problem and product oriented approach: YES!

• Technology oriented approach: NO!• Technology: manufacturability.• Important technologies are not silicon

based:– Mechanical micromachining.– High aspect ratio microstructuring

(LIGA).– Replication methods:

• Electroplating,• Injection molding.• Hot embossing.

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Availability of Production

• Many prototypes of sensors.• Small number on the market.• Prototyping labs are not equipped to

make 100,000 devices batchs.• Moving the prototype to a foundry

implies on starting again from the scratch.

• Orders of less than 250,000 devices are not attractive to silicon foundries.

• Multi-User prototyping approach (The MUSA Project).

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COSTS• CMOS foundry for monolithically

integrated sensors: US$30 Millions.• Micromechanical parts line (if the ion

implantation is made externally): US$4 Million.

• Hybrid integration (assembly and thick film line): US$1 Million.

• CMOS processed silicon: US$ 2.5 to 8. Cent per mm2 = US$750 to 2100 for a processed 20cm waver.

• Sensor process: US$0.35 per mm2 for batch of more than 50,000 chips.

• Surface micromachining; US$1.80 per mm2 for 10,000 Chips batch, and 30 cents per mm2 for 500,000 chips batch.

• Less than 1 Million chips per year is a risk.• Bellow 10,000 chips a year: a big problem.

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People Demand

• 1996: total= 48,000

• USA Japan Europe

• 29,000 13,000 6,000

• 2002: projected total=100,000