thermomechanical analysis (tma)tma: the technique • thermomechanical analysis measureschanges in...

Thermomechanical Analysis (TMA)熱機械分析儀，原理與應用

許炎山TA Instruments, Waters LLC

美商沃特斯國際股份有限公司台灣分公司

TA Taipei office: 104臺北市長安東路1段23號4F之5

Tel: 02-25638880 Fax: 02-256388700928-168676

[email protected]

逢甲大學校本部商學大樓8樓第八國際會議廳2016年8月5日(五)

TMA: The Technique

• Thermomechanical Analysis measureschanges in the dimensions of a sample as a function of time, temperature and force in a controlled atmosphere.

• TMA can measure Coefficient of Thermal Expansion (CTE), along with transitions like Tg

• Can also make viscoelastic measurements

TMA: What TMA Can Tell You

Compatibity of materials that must function together: e.g., coatings and their substrates, adjacent layers of laminates, resins or elastomers and their reinforcements or fillers, seals or encapsulants and the mechanical systems they protect

Suitability of materials for use in harsh environments and temperature extremes: e.g., brake linings, automotive gaskets, window seals, solder joints, adhesives, and protective coatings

TMA: What TMA Can Tell You

Physical characteristics and mechanical properties of materials, including films and fibers

Optimum processing conditions for manufacturing efficiency, economy and product quality, including the ability to monitor rate and degree of cure of polymers

熱性質與狀態改變(1)First-Order Transition

ΔG=ΔH-TΔS

熱性質與狀態改變(2)

ΔG=ΔH-TΔSSecond-Order Transition

α1

α2

Cp1

Cp2

Q400 TMA (EM)

TMA 2940/Q400/Q400EM Key Schematic

Furnace

FurnaceAssembly

Stage

LVDT

SuspensionAssembly

Force CoilAssembly Shuttle

Stepper Motor

FurnaceLift Motor

LeadScrew

Sample

Probe

CoolantReservoir

樣品內置與外放的比較

內置

外放

TMA: Types of probes

11

• Compression• Expansion• Penetration• Dilatometry• Parallel Plate Rheometry• Flexure

•Tension•Films and Fibers

TMA: Common Probes

Standard Expansion

Macro Expansion

Penetration Hemispherical

Expansion Penetration

• Measures:• Coefficient of Thermal Expansion (CTE)• Glass Transition Temperature• Compression Modulus of Polymeric Materials

• The flat tipped standard probe is used for most solid materials

• The macroexpansion probe (larger surface area) is more effective for soft or irregular samples, powders, frozen liquids, and films

TMA: Expansion Probes

TMA: Penetration Probes

• Measures:• Softening and Melting Points• Coating and Film Evaluation

• An optional probe with a hemispherical tip offers an alternate means for obtaining softening point data

TMA: Less Common Probes

Film/Fiber Tension Three-Point Bend

TMA: Flexure (3-P-B) Probe and Stage

Knife-EdgedLoading Nose

Knife-EdgedSupports

Sample

LOAD

Sample Length =5.08 mm (0.2 in.)

Measures the deflection (bending) properties of stiff materials such as laminates and composites

The sample rests on a two-point anvil positioned on the stage, while a wedge-shaped probe applies force

TMA: Film/Fiber Probe (Old)

FILM CLAMPRELIEF NOTCHAT TOP

STRAIGHT EDGEAT BOTTOM

FILM SAMPLE

STRAIGHT EDGEAT TOP

FILM CLAMPRELIEF NOTCHAT BOTTOM

Film FiberTension

TMA: Q400 Film/Fiber Probe (New)

Flange to keep clamp from rocking

TMA: Low-Friction Al Fixture

The low-friction aluminum fixture consists of an aluminum three-point bend platform with two rollers spaced 10.16 mm apart. It is not recommended for use in thermal expansion experiments

TMA: Equations for Estimation of Flexural Stress, Strain, Modulus

S = 3PL2bd2

r = 6DdL2E = s/r = PL

4bDdb

3

3

S = Stress, MPa (psi) L = Span, mm (in.)r = Strain, mm/mm (in./in.) b = Width, mm (in.)Eb= Modulus of Elasticity, MPa (psi) d = Depth, mm (in.)P = Load, N (lbf) D = Deflection of Mid-Span, mm (in.)

TMA: Sample Preparation andOperating Conditions

• Sample Preparation• Bulk Samples - parallel faces for expansion

- reasonably flat for penetration• Films/Fibers - cut and mount using fixture

- use razor to avoid tears/cracks

• Force (maximum programmable is 1.0N)• Expansion - low force (0.001N to 0.05N)

(0g to 5g)• Penetration - higher force (0.05N to 0.5N)

(5g to 50g)

TMA: Sample Preparation and Operating Conditions

• Heating Rates• Use slow heating rates to prevent thermal

gradients (< 5°C/min)

• Purge Gas• Below 300°C - Helium is used because of

excellent thermal conductivity• Above 300°C - Nitrogen is used (helium will

overwork furnace at higher temperatures)• Flow Rate = 100mL/min.

Mechanical Cooling Accessary MCA 70

Uses the RCS90 compressor system Redesigned heat exchanger Faster Cooling MUCH less frosting Auto-recognition Event control capability

Thermomechanical Analysis(TMA)

Applications

TMA and The Concept ofFree Volume

自由體積Free Volume

IPC-TM-650 2.4.24.5 Glass Transition Temperature and Thermal Expansion of Materials Used

in High Density Interconnection (HDI) and Microvias - TMA Method

Method AVolumetric or Z-axis expansion – thick specimens (>0.50 mm): Method BIn-plane (x-y) expansion – thin specimens (<0.5mm):

內應力的生成

分子取向

未ラビング

複屈折：小

ラビング

複屈折：大複屈折の立体的な評価

液晶配向膜：ラビング光学位相フィルム光ディスク基板

TMA: Schematic Diagram ofThermal Expansion Mismatch

A.M./ Ibrahim, etal. inMaterials Characterization by Thermomechanical Analysis,ASTM STP,1136, A.R. Riga and C. M. Neag, Eds., ASTM, Phila., (1991), pp 161-167

Leadless CeramicChip Carrier (LCCC)CTE 5.9-7.4 ppm/°C

PCB Substrate(fabric/resin composite)CTE 12-16 ppm/°C

StressedSolderJoints

TMA: CTE MismatchThermal Stress (熱應力)的評估

A.M./ Ibrahim, etal. inMaterials Characterization by Thermomechanical Analysis,ASTM STP,1136, A.R. Riga and C. M. Neag, Eds., ASTM, Phila., (1991), pp 161-167

Leadless CeramicChip Carrier (LCCC)CTE 5.9-7.4 ppm/øC

PCB Substrate(fabric/resin composite)CTE 12-16 ppm/℃

StressedSolderJoints

σ=Eαl (To-Tf)E: modulus of elasticityαl (To-Tf)= ε ,ε:thermal strain

31

TMA: CTE Versus % Cure for SMC

93 94 95 96 97 98 99 10055

60

65

70

75

80

85

Percent Cure

CLT

E (p

pm/C

)R. D. Adams in Materials Characterization by Thermomechanical Analysis, ASTM STP, 1136, Riga and Neag Eds., ASTM, Phila. (1991) pp 150-160

研發舉例

Ａ. 增加樹脂的Tg B. 增加填充物的含量

TMA: Expansion Measurements

•Expansion Coefficient

•Glass Transition

•Delamination/Decomposition

TMA: Coefficient of Thermal Expansion

• Coefficient of Thermal Expansion (CTE)• Quantitative measurement of change in length(∆ L) with change in temperature (∆T)

• Important in many applications but especially in composite structures

• Results can vary significantly with samples having oriented structure due to processing (tension, pressure, cooling rate, etc.)

• High accuracy/reproducibility usually obtained with samples >5mm thick

TMA: Definition of Coefficient of Thermal Expansion CTE (

Differential or point definition

Slope definition

= 1L

dLdTo

= 1L

LTo

Cell Constant

The cell constant in TMA is typically ran with Aluminum in Calibration modeThis works well for most materials (typical polymers) ran in the compression or tensile modeWhen the materials CTE gets too low (below 5 µm/(m°C), the error increasesASTM E831 refers to this

Materials with lower CTE’s can be measured if an appropriate material is used for calibration of the cell constantTo do this the cell constant must be calculated manually

Expansion of 7.6 mm Aluminum Standard

TMA: Expansion of 0.25mmDiameter Aluminum Wire

0 50 100 150 200 250 300 350 400 450-10

0

10

20

30

40

50

60

70

80

90

TEMPERATURE (°C)

DIM

ENSI

ON

CH

AN

GE

(mm

)

+227.0°Ca = 20.4mm/m°C

+ 77.0°Ca = 20.4mm/m°C

Calibration Constant(K = 1.22)

Fiber Probe

Prog: 10°C/minSize: 10 mm

Coefficient of Thermal ExpansionCalculation Methods

at X

X1 to X2

Fit X1 to X2

TMA: Polyimide Film

20 40 60 80 100 120 140 160-5.3

-5.2

-5.1

-5.0

-4.9

Temperature (°C)

Dim

ensi

on C

hang

e (m

m)

74.98°C

113.16°Ca = 71.3m/m°C

Cell Constant

Data

The data on the following slides were run with a cell constant of 1The data were analyzed and cell constant’s calculatedThe data were re-analyzed with the appropriate cell constants.

Aluminum Before Calibration

58.66°C

149.45°CAlpha=22.58µm/(m·°C)

Ran and Analyzed with a cell constant of 1

Based on a CTE of 23.6µm/(m°C)

Size: 23.9771 mm

-50

0

50

100

150

Dim

ensi

on C

hang

e (µ

m)

-50 0 50 100 150 200

Temperature (°C) Universal V4.5A TA Instruments

Aluminum After Calibration

Ran with cell constant of 1Analyzed with cell constant of 1.04 in UA

58.66°C

149.45°CAlpha=23.48µm/(m·°C)


Size: 23.9771 mm

-50

0

50

100

150D

imen

sion

Cha

nge

(µm

)

-50 0 50 100 150 200


Platinum Before Calibration

40.00°C

125.00°CAlpha=10.89µm/(m·°C)


.84


Size: 7.9578 mm

-4

-2

0

2

4

6

8

10

Dim

ensi

on C

hang

e (µ

m)

0 20 40 60 80 100 120 140 160


Platinum After Calibration

40.00°C

125.00°CAlpha=9.149µm/(m·°C)


Size: 7.9578 mm


-2

0

2

4

6

8D

imen

sion

Cha

nge

(µm

)

0 20 40 60 80 100 120 140 160


Tungsten Before Calibration



Size: 24.0338 mm

25.00°C

150.00°CAlpha=1.865µm/(m·°C)

18

20

22

24

26

28

30D

imen

sion

Cha

nge

(µm

)

-50 0 50 100 150 200


Tungsten After Calibration


Size: 24.0338 mm


25.00°C

150.00°CAlpha=4.606µm/(m·°C)

45

50

55

60

65

70

75D

imen

sion

Cha

nge

(µm

)

-50 0 50 100 150 200


Conclusions of CTE measurement

TMA can be used for low CTE materials, but to get the best accuracy a cell constant with a similar expansion should be usedThe instrument can be run with a cell constant of one, and the correct value entered when opening the file in UAThis allows post test implementation for the correct cell constant which gains additional flexibility for the user

thermomechanical analysis (tma)tma: the technique • thermomechanical analysis measureschanges in...

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