To Start this Seminar - chemilab.comchemilab.com/mtxa/seminar/20120323/2.pdf · 4 Analysis , Development and Enhancement 표면뱩봃장치 SPM(Scanning Probe Microscope ) 의의의의종류종종류류종류-AFM

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Analysis , Development and Enhancement

서론서론서론서론 및및및및 기계적기계적기계적기계적 물성물성물성물성 측정측정측정측정 현황현황현황현황.(.(.(.(원리와원리와원리와원리와 응용응용응용응용))))

f|Å \Ç VâÄf|Å \Ç VâÄf|Å \Ç VâÄf|Å \Ç VâÄ


1. Organic Materials(Polymers)에 대한 관점

2. Vision은 깊게, Touch는 넓게.유기물질은 보이는 현상과는 다른 화학적 물리적 조성에의한 변수가 매우 다양하고, 환경(온/습도)에 의한 변화가시간에 따라 동적으로 결정됩니다.

3. 측정 기구와 측정 변수의 한계는 분명히 다르므로 측정 기구의 선택은 신중해야 합니다.

4. (사용효율/장비 가격) X 100 = 100% ?????

To Start this Seminar

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MEMS(Micro Electro Mechanic System) & NEMS(Nano Electro Mechanic System)

- MEMS : Micrometer, g(mg) 수준의 길이, 하중을 조절, 측정, 구성할 수 있는 전자 기계 체계.- NEMS : Nanometer, ug(ng) 수준의 길이, 하중을 조절, 측정, 구성할 수 있는 전자 기계 체계.

NEMSNEMSNEMSNEMS

(nm, ug, ng)

MEMSMEMSMEMSMEMS

(um, g, mg)

MKS/CGS

(cm, mm, kg, g)

사용 및 요구 현황(계측 및 가공 장치 분포)

투자 및 연구 현황

NEMSNEMSNEMSNEMS

(nm, ug, ng)

MEMSMEMSMEMSMEMS

(um, g, mg)

MKS/CGS

(Ton, m, cm, mm, kg, g)

후 가공/표면가공(코팅, 증착, 점착)소재 사용 분포

2012 -> 2013 NEEDS : Machine with mks/cgs unit-> MEMS -> NEMS


기능성~정밀도 정밀도

Milli Micro

Nano

Micro

Milli

Kilo & Milli

정밀도<기능성

길이와 하중의 정밀도 조절 및 측정• 제품의 규격 평가 관점 : 성능 > 정밀도 > 정확도

• 학술적 평가 관점 : 성능 > 정밀도 > 정확도

소재 구성 수준에 따른 재료 및 표면 측정 장치

• 나노 소재

•의료, 바이오

•전기 전자

•제약, 의료

•반도체/디스플레이

•치공구

•자동차, 기계

•반도체

•의료

•우주항공비접촉비접촉비접촉비접촉 표면표면표면표면 측정측정측정측정

Laser

CCDSEM

접촉식접촉식접촉식접촉식 표면표면표면표면 측정측정측정측정

3차원형상차원형상차원형상차원형상

표면조도표면조도표면조도표면조도

AFM

Nano UTMHysitron(USA)

CSM(SWISS)Micro Materials(UK)

Asylum Res.(USA)Nanovea(USA)

Miniature UTMTOPTAC2000TXi(UK)RheometerDMA

microTXA

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측정 요구 규격에 따른 장비의 정밀도/대상 장비

표면

특성

표면

특성

표면

특성

표면

특성

kg, m

g, cm, mm

mg, um

ug, ng, nm

재질

특성

재질

특성

재질

특성

재질

특성

kg, m

g, cm, mm

mg, um

ug, ng, nm

측정측정측정측정 요구요구요구요구 Control 신뢰성신뢰성신뢰성신뢰성

kg, cm

g, mm, um

mg, nm

ug, ng, nm, pm

측정측정측정측정 요구요구요구요구 Control 신뢰성신뢰성신뢰성신뢰성

kg, cm

g, mm, um

mg, nm

ug, ng, nm, pm

대상대상대상대상 장비장비장비장비(응력응력응력응력 조절조절조절조절 측정측정측정측정 가능가능가능가능 장비에장비에장비에장비에 한함한함한함한함)

Micrometer

표면조도측정, 3차원 형상측정

기타 비접촉 측정 장비 : SEM, TEM, Laser Vision, CCD Vision, Ultra Sonic etc.

AFM

TOPTAC2000, Texture Analyzer

Rheometer

TMA, DMA, Dilatometer

microTXA

microTXA

UTM

Nano UTM

대상대상대상대상 장비장비장비장비(응력응력응력응력 조절조절조절조절 측정측정측정측정 가능가능가능가능 장비에장비에장비에장비에 한함한함한함한함)


표면재질분석표면재질분석표면재질분석표면재질분석방법방법방법방법

접촉식접촉식접촉식접촉식비접촉식비접촉식비접촉식비접촉식

광학적광학적광학적광학적분석분석분석분석전기전기전기전기////전자전자전자전자특성특성특성특성 분석분석분석분석

실측영상분석실측영상분석실측영상분석실측영상분석관능분석관능분석관능분석관능분석

점탄성점탄성점탄성점탄성 측정측정측정측정 방법방법방법방법

RheometerDMATexture analyzer(Toptac Series)UTM

표면표면표면표면 조도계조도계조도계조도계3333차원차원차원차원형상측정형상측정형상측정형상측정

점착력점착력점착력점착력측정측정측정측정

표면 조성분석 방법

AFMSEMEPMA/ESCAFTIR/ATR/Image scan

microTXA

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표면분석 장치

SPM(Scanning Probe Microscope )의의의의 종류종류종류종류

- AFM ( Atomic Force Microscope ) : 부도체부도체부도체부도체 시료의시료의시료의시료의 측정측정측정측정 가능가능가능가능

- STM ( Scanning Tunneling microscope ) : 최초의최초의최초의최초의 원자원자원자원자 현미경현미경현미경현미경

- MFM ( Magnetic Force Microscope ) : 시료의시료의시료의시료의 자기력자기력자기력자기력 측정측정측정측정 가능가능가능가능

- LFM ( Lateral Force Microscope ) : 시료시료시료시료 표면의표면의표면의표면의 마찰력마찰력마찰력마찰력 측정측정측정측정 가능가능가능가능

- FMM ( Force Modulation Microscope ) : 시료의시료의시료의시료의 경도경도경도경도 측정측정측정측정 가능가능가능가능

- EFM ( Electrostatic Force Microscope ) : 시료의시료의시료의시료의 전기적전기적전기적전기적 특성특성특성특성 측정측정측정측정 가능가능가능가능

- SCM ( Scanning Capacitance Microscope ) : 시료의시료의시료의시료의 capacitance 측정측정측정측정 가능가능가능가능


ROUGHNESS MEASURING EQUIPMENT

ROUGHNESS (거칠기) 측정은 기재의 거친 정도를 측정함으로써 기재 거칠기를 측정하는 하나의 지수로써 사용된다. 기재가 심한 거칠기를 가질 경우 그로인한 CRACK/BROKEN이 예상된다.

ROUGHNESS SPEC LIMIT : MAX 0.3 um

PRINCIPLE OF MEASUREMENT : STYLUS METHOD (CONTACT)LASER METHOD (NON-CONTACT)

MEASURING RANGES : 0.25 mm

Measure LengthL

RmaxRa

Y

Xf(x)

Ra = 1/L∫ 0L

f(x) dx

용어 정리

• Rmax (최대 높이) : 한 기준 길이 안에서 단면 곡선의 최저점으로 부터 최고점까지의 높이

• Ra (중심선 평균 거칠기) : 한 기준 길이내의 산과 골의 높이를 기준선을 중심으로 평균하여 얻어지는 값

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3차원 형상 측정기 개발 현황

(출처 덕인/KRISS 측정클럽 발표 자료)


PDP 격벽 3D 레이저(CCD) 구조 분석 사례

KRISS 측정클럽 발표자료

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I wonder if some stress applied…As a view point of Material Viscoelasticity

And very small stress have applied…


Principles of Rheology (cont’d.)

Introduction to Viscoelasticity

• Most materials behave such that they have a combination of viscous and elastic

responses under stress or deformation.

• Materials behave in the linear manner, as described by Hooke and Newton, only

on a small scale in stress or deformation.

Most MaterialsIdeal Solid Ideal Liquid

Hooke Newton

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Dynamic Mechanical Analyser의의의의 개념개념개념개념

점탄성의 측정


DMA Curves for Epoxy resin

8


Schematic Concept

56789

10

Glassy Rubbery

Cross-linked

Temperature

A

B

C

DE

Deformation

MolecularMotion

UnstrainedState

StrainedState

E D C B AHookeanBehavior

SecondTransition

PrimaryTransition Highly Visco Elastic Flow

(rubbery)(gamma) (beta) (alpha)

Bend &StretchBonds

SideGroups

MainChain

GradualMain Chain Large

Scale MobilityChain

Slipping

Increasing

F

FSecondaryDispersion

LocalizedMotion

R. Seymour, 1971

(melt)

34

11

Crystal-crystal slip

Crystalline Polymer


Common changes show as:

E’E’E’E’

tan tan tan tan δδδδ

MW MWD Crosslink Density Crystallinity

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• Stress or Strain is varied sinusoidally

Oscillation Experiments of Rheometer

Stimulus

Response

phase lag, δ

• Separates Elastic and Viscous effects

• The modulus and Viscosity of Oscillation experiments are called Complex ModulusComplex ModulusComplex ModulusComplex Modulus and Complex Complex Complex Complex ViscosityViscosityViscosityViscosity.


Linear and Non-Linear Stress-Strain Behavior of Solids

Non-Linear RegionG = f(γ)

Linear RegionG is constant

σ

GGGG

1000.00.010000 0.10000 1.0000 10.000 100.00% strain

1000

1.000

10.00

100.0

100.0

0.01000

osc.

str

ess

(Pa)

Critical Strain γc

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Newtonian and Non-NewtonianBehavior of Fluids

γ

σ

ηηηη

Newtonian Regionη Independent of γ

Non-Newtonian

Region

η = f(γ)

1.0001.000E-5 1.000E-4 1.000E-3 0.01000 0.1000

shear rate (1/s)

1.000E5

10000

η η η η (P

a.s)

1.000E5

1.000

10.00

100.0

1000

10000

σσ σσ(P

a)


Molecular functional groups vs. Thermal behavior

• 관능기의 가지가 크면 Tg, Tm 감소 – alpha, beta, gamma, delta transition• 관능기의 입체 규칙성 증가-결정도 증가-Tg, Tm 증가

• 관능기의 2차 결합(수소결합, Van der waals, chelation, etc.)-구조적 치밀도 증가-Tg, Tm 증가

• Dipole mement 존재(-Cl, -F)-치밀도 증가

• Benzene ring 포함-Tg, Tm 급상승

분자량 vs. Thermal behavior

• 분자량이 커지면 Tg, Tm 상승

• 일정 분자량 이상에서는 Tg, Tm 감소 가능성

• 분자량 분포가 좁을수록 Tg, Tm 상승

• 분자량 분포가 넓은 이유는 저분자량 영향

• 점도는 분자량에 직접 영향

Impurity vs. Thermal behavior

• 수분, 이온, low molecules, oligomer• 상호 작용이 없이 단순히 mix되어 있는 경우-Tg, Tm 감소- 구조적 혼란

• 상호 작용 존재-치밀도 상승-seed 역할

• Critical point 존재-임계함량 이상은 Tg, Tm 감소 및 구조 파괴

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공중합체의 Tm, Tg

불규칙 공중합체는 결정성 파괴로 Tm 및 결정화도 감소 → 하나의 Tg

Block 및 Graft 공중합체는 미세 상분리 → 성분중합체 각각의 Tm, Tg 가능

고분자 혼합물(blend)의 Tg

상용성이 없으면 각각의 Tg

상용성이 있으면 중간에 하나의 Tg

용매, 가소제가 혼합되면 Tg 강하

일반적으로 Tg ; 1/2 ~ 2/3 Tm

간단하고 대칭성 구조이면,

입체 규칙성이 크면,

분자간 인력 또는 결합이 강하면,

곁가지가 없고 분자량이 크면,

높은 Tm 및 결정화도

사슬의 유동성이 작을수록(방향족 사슬등)

치환기의 크기와 극성이 클수록

분자량이 클수록 (어느 한계까지)

가교도가 증가할수록

높은 Tg


표면에의 응력 적용

90%~

Stress

50%~60%~

80%~

50%~60%~

80%~

Applied force of Total stress

95%~50%~30%~

Creep Recovery

Elastic Viscous

Values as a results:Length, Load

[Temperature/Time & Humidity]

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Basic Parameters and UnitsBasic Parameters and UnitsBasic Parameters and UnitsBasic Parameters and Units

S.I. units = c.g.s. X 10

2222Stress = Force /Area [Pa, or dyn/cm ]

σσσσ = tensile stress, ττττ = shear stressStrain = Geometric Shape Change [no units]

εεεε = tensile strain, γγγγ = shear strainStrain or Shear Rate = Velocity Gradient or d(strain)/dt [1/s]

εεεε = tensile strain rate, γγγγ = shear strain rateModulus = Stress / Strain [Pa or dyn/cm ]

E = Youngs or Tensile, G = Shear ModulusCompliance = Strain / Stress [1/Pa or cm /dyn]

Typically denoted by JViscosity = Stress /Strain Rate [Pa.s or Poise]

Denoted by ηηηη

2222

........

2222


Viscoelasticity DefinedViscoelasticity DefinedViscoelasticity DefinedViscoelasticity Defined

Range of Material BehaviorSolid Like ---------- Liquid Like

Ideal Solid ----- Most Materials ----- Ideal FluidPurely Elastic ----- Viscoelastic ----- Purely Viscous

Viscoelasticity: Having both viscousand elastic properties

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Response for Classical ExtremesResponse for Classical ExtremesResponse for Classical ExtremesResponse for Classical Extremes

Purely ElasticResponse

Hookean Solidσ = Eε or τ = Gγ

Purely ViscousResponse

Newtonian Liquidσ = ηγ

In the case of the classical extremes, all that matters is the values of stress, strain, strain rate. The response isindependent of the loading.

Spring Dashpot


At short times (high frequencies) the response is solid-like

At long times (low frequencies) the response is liquid-like

THE HISTORY OF LOADING IS CRUCIAL

Response for a Viscoelastic MaterialResponse for a Viscoelastic MaterialResponse for a Viscoelastic MaterialResponse for a Viscoelastic Material

14


TimeTimeTimeTime----Dependent Viscoelastic Behavior:Dependent Viscoelastic Behavior:Dependent Viscoelastic Behavior:Dependent Viscoelastic Behavior:Solid and Liquid Properties of "Silly Putty"

T is short [< 1s] T is long [24 hours]

Deborah Number [De] = τ / Τ


Old Testament Prophetess who said :"The Mountains Flowed before the Lord"

Everything Flows if you wait long enough!

Deborah Number, De - The ratio of a characteristic relaxation time of a material (τ) to a characteristic time of the relevant deformation process ( Τ ).

De = τ/Τ

TimeTimeTimeTime----dependent Viscoelastic Behavior:dependent Viscoelastic Behavior:dependent Viscoelastic Behavior:dependent Viscoelastic Behavior:The Deborah Number

15


Hookean elastic solid - τ is infiniteNewtonian Viscous Liquid - τ is zeroPolymer melts processing - τ may be a few seconds

High De Solid-like behaviorLow De Liquid-like behavior

IMPLICATION: Material can appear solid-like because1) it has a very long characteristic relaxation time or2) the relevant deformation process is very fast

The Deborah NumberThe Deborah NumberThe Deborah NumberThe Deborah Number


Stress Relaxation ExperimentStress Relaxation ExperimentStress Relaxation ExperimentStress Relaxation Experiment

Response of Classical Extremes

time

0

time

0

stress for t>0is constant

time

0

stress for t>0 is 0

Hookean Solid Newtonian Fluid

16


Stress Relaxation ExperimentStress Relaxation ExperimentStress Relaxation ExperimentStress Relaxation Experiment

Response of Material

For small deformations (strains within the linear region) the ratio of stress to strain is a function of time only.

This function is a material property known as the STRESS RELAXATION MODULUS, G(t)

G(t) = σ(t)/γ

Stress decreases with timestarting at some high value and decreasing to zero.

time

0


Stress is applied to sample instantaneously, t1, and held constant for a specific period of time. The strain is monitored as a function of time (γ(t) or ε(t)).The stress is reduced to zero, t2, and the strain is monitored as a function of time (γ(t) or ε(t)).

Creep Recovery ExperimentCreep Recovery ExperimentCreep Recovery ExperimentCreep Recovery Experiment

Str

ess

timet1 t2

17



Response of Classical Extremes

– Stain for t>t1 is constant– Strain for t >t2 is 0

time

time

time

– Stain rate for t>t1 is constant– Strain for t>t1 increase with time– Strain rate for t >t2 is 0

t2t1

t1 t2t2t1

Analysis , Development and EnhancementReference: Mark, J., et.al., Physical Properties of Polymers ,American Chemical Society, 1984, p. 102.

Creep Recovery Experiment:Creep Recovery Experiment:Creep Recovery Experiment:Creep Recovery Experiment:Response of Viscoelastic Material

Creep σ> 0

timet 1 t2

RecoverableStrain

Recovery σ = 0 (after steady state)

σ/η

Strain rate decreases with time in the creep

zone, until finally reaching a steady state.

In the recovery zone, the viscoelastic fluid recoils, eventually reaching a equilibrium at some small total strain relative to the strain at unloading.

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time

Recovery ZoneCreep Zone

Less Elastic

More Elastic

Creep σ > 0 Recovery σ = 0 (after steady state)

σ/η

t1 t2



Definition of Rheology

• Rheology is the science of flow and deformation of matter.

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Geometry of Shear for RheometersGeometry of Shear for RheometersGeometry of Shear for RheometersGeometry of Shear for Rheometers

Plate & PlatePlate & PlatePlate & PlatePlate & Plate

Cone & Cone & Cone & Cone & PlatePlatePlatePlate

Concentric CylindersConcentric CylindersConcentric CylindersConcentric Cylinders

Motor applies Torque, Strain read from Optical Encoder.

TorsionTorsionTorsionTorsion


MotionMotionMotionMotion

Flow(Flow, Creep,

Stress Relaxation)

Oscillation Squeeze Flow/Pull Off

20


γ = Strain γ = Strain Rate σ = Stress

Kγ = Strain Constant Kσ = Stress Constant

θ = Angular Motor Deflection M = Torquein Radians

Gc = Gravity constant = 98.07 Pascals (SI)= 980.7 dyn/cm2 (cgs)

Ω = Motor angular velocity in radians/sec.β = Cone angle in radiansH = Gap for parallel plate in mmR = Radius of plate or cone in mmR1 = Radius of concentric cylinder bob in mmR2 = Radius of concentric cylinder cup in mm

List of Symbols


Typical Viscosity Values (PaTypical Viscosity Values (PaTypical Viscosity Values (PaTypical Viscosity Values (Pa----s)s)s)s)

Asphalt Binder ------------------

Polymer Melt --------------------

Molasses --------------------------

Liquid Honey --------------------

Glycerol --------------------------

Olive Oil -------------------------

Water -----------------------------

Air ---------------------------------

100,000

1,000

100

10

1

0.01

0.001

0.00001

Need for Log scale

21


More on ViscosityMore on ViscosityMore on ViscosityMore on Viscosity

According to Isaac Newton, viscosity is constant for all times and shear-rates –Newtonian Fluids

Viscosity is dependent on Temperature and Pressure

Viscosity may not be constant – Non-Newtonian Fluids

Viscosity of Non-Newtonian fluids can depend on– Time :– Thixotropy, Rheopexy– Shear-rate :– Shear-thinning, Pseudoplasticity, Dilatency

Time-DependenceAt constant shear-rate, if viscosity

– Decreases with time - Thixotropy– Increases with time - Rheopexy


Non-Newtonian, Time Independent Fluids

Shear-ThinningA decrease in viscosity with increasing shear

rate. Also referred to as Pseudoplasticity.

Shear-ThickeningAn increase in viscosity with increasing shear

rate. Also referred to as Dilatancy (a special case of shear-thickening).

22


Non-Newtonian, Time Dependent Fluids

ThixotropyA decrease in apparent viscosity with time under

constant shear rate or shear stress, followed by a gradual recovery, when the stress or shear rate is removed.

RheopexyAn increase in apparent viscosity with time under

constant shear rate or shear stress, followed by a gradual recovery when the stress or shear rate is removed. Also called Anti-thixotropy or negative thixotropy.

Reference:Barnes, H.A., Hutton, J.F., and Walters, K., An Introduction to Rheology, Elsevier Science B.V., 1989. ISBN 0-444-87469-0


Non-Newtonian, Time Dependent Fluids

time

Vis

cosi

ty

Thixotropic

Rheopectic

Shear Rate = Constant

23


TimeTimeTimeTime----Temperature Superposition PrincipleTemperature Superposition PrincipleTemperature Superposition PrincipleTemperature Superposition Principle

TTS is an EMPERICAL relationship

TTS is based on the observation that, for a single material,the curves of the viscoelastic properties, generated at different temperatures, are similar in shape when plotted againstlog time or log frequency. The Curves generated at differenttemperatures can be exactly superimposed by shiftingalong these axes.

TTS applies to stress relaxation, creep and dynamic mechanicalmeasurements


Time and Temperature: Two Sides of the Same CoinTime and Temperature: Two Sides of the Same CoinTime and Temperature: Two Sides of the Same CoinTime and Temperature: Two Sides of the Same Coin

(E" or G")(E' or G')

(E" or G")

(E' or G')

log Frequency

Temperature

log Time

log Time

24


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