Smart System Integration Technologies

enabling new devices and miniaturized

modules on plastic substrates

Luigi Occhipinti

STMicroelectronics

Industrial & Multisegment Sector (IMS)

R&D – SSI / FDE

0

Plastic Electronics Dresden, 9 Oct. 2012

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Harvesting Device

(PV, Piezo, etc)

Wireless Transmission : RFID, low power radio, BLE, …

Sensors Sensor Interface,

Analog FE

Energy Storage :

Supercap, Flexible

Batteries

Low Power Digital

Processing

Power Management

Combining IP portfolio and hybrid

integration technologies

Integrated Smart Systems 1

Smart Systems are everywhere

2

Emerging Applications require Smart Integration: Moore’s Law and More than Moore

“ More than Moore ” : Diversification

“ M

oo

re’s

Law

” :

M

inia

turiz

ati

on

Ba

se

lin

e C

MO

S :

C

PU

, M

em

ory

, L

og

ic

Biochips Sensors

Actuators

HV

Power Analog/RF Passives

130nm

90nm

65nm

45nm

32nm

22nm . . .

V

130nm

90nm

65nm

45nm

32nm

22nm . . .

V

Information Processing

Interacting with people and environment

Beyond CMOS:

Quantum Computing,

Molecular Electronics

Spintronics

Moore approach: integrate more transistors in a chip

More than Moore: integrate functions in a Systems

Innovation in More than Moore comes in disruptive steps

3

Flexible Electronics: enabling of broad range

applications by diversification (More than Moore)

Healthcare

& Fitness Automotive &

Transportation

Ambient

Intelligence

Wearable

Electronics Gaming &

Leisure

Portable

Consumer Flexible Conformable

Self Powered Autonomous

Wireless Dislocation

Cost Effective Disposable

Light Portable

Human

Interface

Security &

Safety

4

Disposable electronics: from sensors to smart systems

Electrodes

(Bio)Sensor

Connector

Electronics

Battery

Disposable A disposable system avoids: Waterproof connector cost Rechargeable battery

Needs low power electronics

Electrodes

(Bio)sensor

Electronics

Battery

A

Electrodes

(Bio)sensor

Electronics

RFID

B

Multi-

sensors

Electronics

Harvesting

Battery

C

5

Flexible Electronics at STMicroelectronics Application fields:

• Printed sensors / Flexible ICs

• Multifunctional systems on foil

• Smart disposables for healthcare

and ambient intelligence

Technologies:

• From litho-based on wafer carriers

… to printed electronics carrier-less

• To Hybrid system integration (e.g. multi-foil)

Wireless Strain Gauge Modules for pressure and temperature

IOP sensor + antenna

Sensors around the body

Examples:

• Sensors on plastic: strain/pressure,

temperature, gas and biosensors

• Smart objects with RF harvesting and

wireless communication

• Transparent and Flexible electronics, incl.

printed organics and oxides

• Implantable sensors for glucose monitoring

• Hybrid Si-Plastic micro-fluidic modules

6

Implantable biosensors for diabetes management

Application: Continuous Glucose

Monitoring (CGM)

Working Reference Counter

Source: www.medtronic.com

As of 2010 about 285 million people around the world, are affected by Type 2 Diabetes Mellitus disease. Complications arising from diabetes can be both Acute and long term and include hypoglycemia, Ketoacidosis, coma, renal failure, amputations, neuropathy, and retinal damage.

In the last decade Glucose sensing technology became the major research focus in diabetes management area, and 80% of biosensor market are the glucose sensors.

Over the next 10 years the cost of diabetes, heart disease,

and stroke will take a tremendous toll on the national

incomes of developing world countries.

According to WHO, diabetes, heart disease, and stroke

together will cost about $555.7 billion in lost national

income in China, $303.2 billion in the Russian Fed.;

$336.6 billion in India; and $49.2 billion in Brazil.

7

http://www.medtronicdiabetes.net/products

Transparent electronics: touch sensor for e-paper

Single side patterning / bridge technology

TCO Patterned by Litho/etch

Transp. Dielectric W>20µm

Conductor W<10µm

8

Printed Organic Electronics

• Dedicated technology platform tested on Organic thin film transistors and circuits

• Transistors with channel length L=2,5,10um

• S/D electrodes by microcontact printing or nanoimprinting

• OSC deposited from solution via inkjet printing

• Top gate by printing

• Characterization and reliability tests

• Compact device model and standard design kit in-house development

• Design and fabrication of all-printed logic circuits on plastic substrates

Elastomeric stamps for uCP

Printed circuits

on plastic foils

9

0 5 10 15 20 25 30

0

5

10

15

20

25

30

Vdd=10V

Vdd=30V

Vdd=20V

Vo

ut

(V)

Vin (V)

Organic CMOS

technology

Electronics on flexible foils with Si carrier

Capability: delivering electronic devices on plastic foils manufactured with ST conventional infrastructure (depreciated)

Si wafer carrier Temporary adhesive tape PEN foil lamination on carrier

Planarization/barrier layer (optional) (Low temperature vapor deposition)

Metallization Multilayer patterning & deposition (by std lithography and/or printing)

Debonding of processed PEN foil by thermal release

Foil detaching, dicing and assembly

Complementary approach to the higher temperature plastic

substrates (spin-on PI)

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Deposition and patterning of Flex Devices on foils

Large area deposition technologies Cluster deposition of metals, organics & oxides at low temperature on

large area (e.g. 40x50cm) substrates glass and plastic foils

Unconventional patterning technologies: Screen printing (by stencil), up to large area substrates Inkjet printing (direct deposition and dedicated tools) Laser scribing and laser annealing Nanoimprinting Microcontact printing/soft lithography

Foil to foil lamination & transfer Adhesive tapes

Permanent photoresist

Graphene transfer on foils

Organic and Printed Electronics

Know-how and IP

11

Developing flexible silicon ICs …

STMicroelectronics has in-house capability to manufacture thinned

8” wafers at 60µm by Taiko process in standard manufacturing

facility.

Technology developments with ultra-thinned wafers (down to

25µm) in R&D for flexible electronics application, based on dicing

before grinding (DBG) process in collaboration with suppliers & R&D

partners

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…and assembly them on Plastic foils

13

Using both conventional flip-chip

approach with high alignment accuracy,

and assessing new materials (e.g. ACA,

NCA, printable metal wires) and methods

for ultra-thin dices on low temperature

substrates

Applications: Smart systems on foil

Wireless strain gauge module

• It’s intended to be a battery-less autonomous system on plastics :

• Thin film strain gauge sensor on a flexible membrane, for monitoring

pressure and temperature within disposable plastic parts (e.g. vials

for drug delivery, contact lens, etc.)

• ASIC device for signal acquisition (analog sensor front end), wireless

energy and data transfer (RF front-end) and standard protocols

management (e.g. NFC)

• EM coupling antenna in the same plastic foil for both energy and data

transfer at short distances (e.g. ~ 1cm)

• An integrated platform and technology to manufacture, test and calibrate

the whole system on foil

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Wireless Strain Gauge module Sensor & antenna foil on Si carrier

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Radial Strain Tangential Strain

Design

Manufacturing

Characterization

Substrate + antenna thickness < 30 µm

Wireless Strain Gauge module The ASIC

• An Application Specific Integrate Circuit has been designed and

developed by ST to provide RF harvesting @ 13.56 MHz, multiple

sensor read-out electronics and NFC compliant wireless link.

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Compliant with NFC standard reader (e.g. ST CR95HF device) and infrastructure (e.g. PC USB RFID reader, NFC mobile phones and Apps)

Die thickness = 40µm

Flexible silicon on flex assembly Actual flow & challenges

• Challenges for ultrathin Si (< 30µm):

• Mechanical issues:

• Handling of ultra-thin wafers

• Stress induced warpage/release

• Defects induced by sawing (low yield)

• EWS (both flat and under bending):

• Drift of electrical parameters (mainly analog)

• Delays in critical paths (mainly digital)

• Leakage / parasitics (mainly analog)

• Optical interference effects

=> Robust design & compensation techniques required

=> Back-metallization / post-processing required

• Assembly Si on Flex substrate

• High accuracy XY alignment (pick and place)

• Defects induced by thermal and pressure

(misalignments along the Z axis)

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Ni/Au UBM

(Stud bumping)

Thinning process

Wafer sawing

Pick & Place

Die mounting

Module Singulation

ASIC Wafer std thickness

Module Finishing

Module Sorting &

Encapsulation

Surface treatment /

Planarization

Adhesion +

Metallization

Flexible substrate on carrier

Passivation &

ACA/NCA dispense

TE

ST

ING

T

ES

TIN

G

TE

ST

ING

Stress induced piezo-electricity on Silicon

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Si chip

Piezo

Sensibility

min

MAX • Doped silicon electrical conductivity is

direction-dependent under specified

directions of applied stress and electric

fields

• The change of resistance is proportional

with applied stress (Piezo-resistive

effect)

• MOS-FET drain current change with

applied stress (Piezo-MOS effect)

The same effect is produced by low-

radius bending of ultra-thin silicon

devices

45°oriented devices are less affected

by stress effects than devices oriented

along the normal axis

P σλ

6

1

Silicon devices structures for minimum piezo-sensitivity

45°oriented P-type MOS

45°oriented N-type Diffused Resistor

45°oriented N-type MOS

Stress-induced piezo-effects sensing Inverter

• Ring-oscillator made by 39 sensing elements • Iref & Temp. var. tolerant • Low power consumption • Very high S/N ratio (50db)

45° devices 90° devices

Basic cell f/fo

90º

45º

0 x

Ultra thin dices: what limits?

• Thickness of < 20 µm is possible using SOI wafers (e.g. FleXTM

technology by American Semiconductor Inc.)

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Source: American Semiconductor Inc. 2011

Pro: ultra-thin Si on flex @ low stress Cons: high cost (SOI wafer), Not compatible with std assembly tools, e.g. flip-chip.

From Healthcare to Ambient Intelligence

• Multifunctional systems embedded in everyday objects:

a) Wireless sensor networks • Autonomous sensors and low-power electronics

with RF & analog processing capability

• Applications:

• Environmental sensors integrated at each node • Ultra Low power and Energy Harvesting (battery or

battery-less)

b) Smart objects in packaging & textile • Applications:

• Electronics on plastics, paper, textile • Gas and chemical sensors in smart objects &

portable devices • Flexible & maybe stretchable electronics associated with other functions and technology drivers: e.g. displays, energy harvesting, RFID

Energy Scavenger Systems 23

Electromagnetic Energy Harvesting 24

Energy Harvesting from Photovoltaic

30 cm2 Flexible PV module

(6” silicon wafer used as carrier)

PolyimideMo 800 nm

a-Si:H p-i-n 250nm

AZO 700nm

0.0E+00

5.0E-05

1.0E-04

1.5E-04

2.0E-04

2.5E-04

0.0E+00

1.0E-05

2.0E-05

3.0E-05

4.0E-05

5.0E-05

0.0 2.0 4.0 6.0 8.0 10.0

Po

we

r (W

)

Cu

rre

nt

(A)

Voltage (V)

Jsc (µA) 43.60

Voc (V) 8.42

Pmax (µW) 238.52

eff (%) 7.98

Fluorescence lamp 300 lux ~ 1W/m2

Jsc (µA) 45.21

Voc (V) 2.73

Pmax (µW) 73.99

eff (%) 6.41

5,5 cm2 PV module

Flexible PV modules of 5,5 and 30 cm2

for indoor use

Thin film solar cells are monolithically

connected in series (13 cells, 4 cells)

RF Harvesting @ 900 MHz

• Charge & Burst mode

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Rx/Tx modulation: ASK

Sensitivity: -20 dBm,

Pwr conv. Efficiency: 20%

Avg bit rate: > 5 kbit/s

Reading distance: 5m indoor (1/d3),

12m free air (1/d2)

RF900A Test chip (1982 µm x 1852 µm)

RF FE IP block (370µm x 260 µm)

Wake-up signal (by RF harvester)

tON=3 ms

2.6 V

Environmental Sensors Product Roadmap 27

Source: ST / AMS group

in mass production

Applications of environmental sensors 28

Source: ST / AMS group

Smartphone can unify the portable sensor world

Portable device for each applications

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The same smartphone platform for

different sensor applications

Wireless communication

between sensor and platform

Sensors miniaturization

Sensor + ASIC on the same package for portable devices

Commercial sensors

Electronics (Potentiostat)

Miniaturized sensor ASIC

EC sensor

Other chemical & gas sensing platforms: pH sensor based on Passive RFID

• Passive RFID based sensors are inductively

coupled LC resonant circuits (a passive RFID

tag) with an associated gas sensing material

(the membrane) affecting the reader.

• Characterized by:

• Existing infrastructure

• Manufactured by lamination of a sensing

film to an RFID tag antenna and chip

• Low cost disposables

• Complex impedance of the RFID antenna is

then correlated to physical, chemical, or

biological properties of interest

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RFID tag @ 13.56 MHz + Sensing layer

RFID IC reader + Impedance analyser

Cell with RFID + sensing

layer and pH solution

Smart System Solutions (SoC, SiP, 3D integration)

Plastic Electronics technology development

Bringing Innovation to the Market

The roadmap: integrating smart systems

into high value products in the market

“we need to invent our future”

Thank you

11/10/2012

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Collaborative R&D programs

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Collaborative research projects

(EC funded project FP7 ICT: MOMA)

• Title: Embedded Organic Memory Arrays

• Project start: • 1 Jan. 2010 (duration 36 months)

• Participants: • TNO-Holst (NL), STMicroelectronics (Italy), Solvay Solexis

(Italy), IMEC (B), RU Groningen (NL), UC Louvain (B)

• Aim: • research the materials, process technologies and electronic

design to make NVM arrays that can be programmed and read

electronically using organic thin-film circuitry on very thin,

flexible plastic foils such as PEN.

• Strategy: • to use soluble ferroelectric polymers in combination with organic

semiconductors.

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Coordinator: Bosch; Partners: CEA, ST-I, Fraunhofer, Infotech, Henkel, ST-F

The project challenge is the development of interconnection technologies for

autonomous, flexible and smart system:

• Interconnection technologies between flexible components and flexible foils as well as

between functional foils.

• Three dimensional functional foil integration to achieve multi-foil based systems, i.e.

system-in-foil.

Technical Demonstrator

Energy autonomous indoor air quality sensing system capable of wireless communication of the measured data.

Duration: 36 Months Project start: 01.01.2010

Collaborative research projects (EC funded project FP7 ICT: INTERFLEX)

Coordinator: Fraunhofer; Partners: CEA, ST-I, TNO, TUE, IMEC, UNICT, CNR, TUB, Friendly, Flexink, Polymer Vision

The project challenge is to develop and set up an Organic CMOS Platform:

• To develop robust and reproducible full-printing process flows;

• Library of Digital and Analogue Building Blocks;

• Organic Design Tool Kit.

Technical Demonstrators

Development of Lead Applications, customized to different electronic markets, in order to investigate the capability of O-CMOS Technology Platform: • ADC Transductor for temperature detection (ST-I); • Arithmetic & Logic Unit – ALU (ST-I); • Silent Tags (Friendly, ST-I and TUE); • Line Driver (IMEC, PV).

Duration: 48 Months Project start: 01.01.2010

Collaborative research projects (EC funded project FP7 ICT: COSMIC)