The document provides an in-depth exploration of heat transfer physics, detailing mechanisms such as conduction, convection, and radiation, along with Fourier's law and Newton's rule. It also covers thermal management strategies, including passive and active cooling methods, and the characteristics of various thermal interface materials (TIMs) used for efficient heat dissipation. Additionally, it emphasizes the importance of material selection for thermal management applications and outlines the unique capabilities of Compatherm in the thermal materials industry.

1. Compatherm
Ankit Sharma
Key Account Manager India
91-9742444088
1

2. Part One
The Physics
of
Heat Transfer
6

3. What Is ”Heat”?
Heat is:
► Thermal power – unit Watts (W)
► Thermal potential (a.k.a. temperature) – unit Kelvin (K) or degrees Celsius (°C)
Heat is transferred through three physical mechanisms:
► Conduction – heat transfer in and between solid bodies in contact, or still fluids
► Convection – heat transfer by movement of mass (molecules) in fluid
► Radiation – heat transfer by electromagnetic radiation

4. Conduction
x
t
AkQ
21
Ak
LQ
tt
Fourier’s Law:
For the geometry shown:
Where:
Q : thermal power k : thermal conductivity A : conductor cross section
t : temperature x, L : distance
A
Q
t1
t2
T
x
L
k

5. Conduction
Thermal Conductivity (k)
► Unit W/(m·K)
► Value determined by
material
Magnitude Material k [W/(m∙K)]
10-2 Still air ~0,02
10-1 Polymers ~0,2
100 TIM’s (typical) ~1+
101 Stainless steel ~20
102 Aluminium extrusion ~200
103 Graphene ~2 000
104 Heat pipes (equiv.) <20 000

6. Convection
Newton’s Rule:
Where:
Q : thermal power h : heat transfer coefficient A : surface area
t : temperature U : freeflow
Ah
Q
ttS
ΔtAhQ
For the geometry shown:
A
Q
tS
t∞
h
U∞

7. Part Two
A
Simplified
Approach
17

8. x
t
kAQ
Fourier’s Law:
Where:
Q : thermal power k : thermal conductivity A : conductor cross section
t : temperature x, L : distance; conductor length; for TIM’s: thickness
A
Q
t1
t2
t
x
L
k
“Heat Accumulation”
Lx
21 ttt
Δt

9. ► Unit K/W
► Value defined by application
Definition:
Thermal resistance is analogous to Ohm’s law, and describes the ratio of temperature difference to
thermal power – i.e. the steepness of the thermal gradient.
cribes the rat
nt.
law, and des
hermal gradie
Thermal Resistance
logous to Ohm’s
eepness of the t
Q
t
R
Ak
L
Ah
1

10. “Heat Accumulation”
► The HEAT is the thermal power (Q)
► The TEMPERATURE (t) is the
consequence of accumulated heat
► Heat accumulates until the thermal
gradient (Δt) can drive the heat
dissipation through the resistance (Rθ)
at the same rate as the heat
generation.
20
)1(IUQ
RQt
Ak
L
R ambcomp ttt
R
t
IU )1(
R
t
Q
Heat in
Heat out
Energy Balance

11. “Heat Accumulation”
► A low resistance allows heat to escape the
system at the same rate as it pours in.
► The heat level – temperature – will not rise.
21
Q
RθΔt
tamb

12. “Heat Accumulation”
► A high resistance will cause the heat level –
temperature – to rise.
► As per this conceptual illustration, the heat level will
continue to rise until the pressure can force the
heat out from the spout at the same rate as it is
poured in.
► When this point is achieved, the temperature will
stabilise (steady state).
While not a strictly true representation, this is sufficiently
analogous to the real physics to promote some intuition for
the mechanics involved.
22
Q
Rθ
Δt
tamb

13. Thermal Management 101
The task of ETM is basically twofold:
2 – Shield
1 – Cool

14. Thermal Management 101
1 – Cool:
Spread DissipateRemove
Facilitate the flow of thermal
power from the heat source
and out into the ambient.

15. Thermal Management 101
2 – Shield:
Screen InsulateDisperseDivert
Control thermal gradients and
thermal resistances so that heat
sources in the system do not cause
a rise in the temperature of heat
sensitive devices.

16. Thermal Management 101
Screen
Insulate
Screen
DisperseDisperse
Divert
SpreadSpread
Dissipate
Remove

17. Part Three
Thermal
Management
Solutions
27

18. The Field of ETM
Passive Cooling
Using only the natural thermal gradient to power the heat transfer
E.g.
Active Cooling
Utilising an external power source to facilitate the heat transfer
E.g.
• TIM
• Spreaders
• Heat Sinks
• Surface Enhancement
• Heat Pipes
• PCM
• Fans
• TEM’s
• Chillers
• Pumped Liquid
• Refrigeration Coolers

19. What Do TIM’s Do, Exactly?
k = 0.02 W/(m·K)
k = 1 – 13.5 W/(m·K)
Ak
L
R

20. TIM Types; Main Categories
Thin Bondline
Materials for the very lowest
thermal resistances.
- Typical bond line 5-100μm
Coated Carrier Film
Hard, silicone rubber coated mesh or
foil.
- Typical bond line 0.1-0.2mm
- Very high DBV (>20kVAC/mm)
Gap Filling
Soft materials that can mitigate large
gaps and tolerances.
- Typical bond line 0.2-6.0mm+
Insulators
PSA Tape
Paste
1-p Fillers
Phase
Change
Graphite
2-p Fillers
Pads

21. Gap Filling Soft Pads
Use Pads For:
► Thick bondlines
► Coarse surfaces
► Height differences
► Tolerance mitigation
► Sensitive components/boards
Height Variations:
Dimensional Tolerances / Tolerance Chains:
Flatness / Planarity / Surface Tolerances:

22. Hardness vs. Deflection Resistance
Gap-filling pad materials are viscoelastic. This means that
the hardness in itself has little or no bearing on what
forces the materials will exert on the surfaces they touch
during deflection.
Parameters such as deflection rate, surface area, and
thickness will however have an absolutely crucial
importance.
32
100 mm/min
50 mm/min
10 mm/min
1 mm/min
0,1 mm/min

23. Hardness vs. Deflection Resistance
While conversely, materials with
nominally identical hardnesses will often
exhibit radically diverging behaviours in
stress/strain tests.
33

24. 37
Thin Bondline Materials
(paste, PCM)(p
20μm < L < 100μm
Ak
L
R
Gap Filling Materials
(pads, fillers)
p g
(pad
0.2mm < L < 6mm+
“Thin Bondline” Explained:

25. Thermal Interface Materials
Product Series
 A comprehensive portfolio of
compliant TIM pads
 Dispensable gap filling TIM
 Screen printable and dispensable
thin bondline TIM

26. 3

27. 4
[W/(m·K)] [Shore00] [g/cm3
] [VAC/mm] [mm]
9410 1 40 2.37 5 000 0.25 - 5.00 Pink
9411 1.3 9 2.50 5 000 0.25 - 5.00 Lt Blue
9420 2 40 2.73 5 000 0.25 - 5.00 Lt Blue
9421 2.5 40 2.70 5 000 0.50 - 5.00 Lt Brown
9422 2 25 2.70 5 000 0.50 - 5.00 Lt Blue
9430 3 60 2.65 400 0.25 - 5.00 Grey
9431 3 40 3.10 > 8 000 0.25 - 5.00 Blue
9432 3 10 2.92 > 7 000 1.00 - 5.00 Brown
9433 3 28 2.65 400 0.25 - 5.00 Grey
9440 4 40 3.10 > 8 000 0.75 - 5.00 Green
9441 4 8 3.10 > 8 000 1.00 - 5.00 Green
9450 5 40 3.10 > 7 000 0.50 - 5.00 Grey
9451 5 28 3.07 > 5 000 0.30 - 5.00 Grey
9452 5 60 3.10 > 5 000 1.00 - 5.00 Grey
9470 7 40 2.55 1 500 1.00 - 5.00 Lt Grey
9471 7 40 3.10 8 000 1.00 - 5.00 Pink
9472 7 20 2.55 1 500 1.00 - 5.00 Lt Grey
9473 7 20 3.10 8 000 1.00 - 5.00 Pink
9480 8 40 3.10 8 000 0.50 - 5.00 Blue
Material Code
Thermal
Conductivity
Hardness Density Colour
Dielectric
Breakdown Voltage
Thickness Range

28. 5
[W/(m·K)] [Shore00] [g/cm3
] [VAC/mm] [mm]
9610 13.5 55 2.70 n/a 1.00 - 5.00 Dk Grey
Material Code
Thermal
Conductivity
Hardness Density Colour
Dielectric
Breakdown Voltage
Thickness Range

29. 6

30. 7
[W/(m·K)] [Pa·s] [g/cm3
] [VAC/mm] [h] [h]
9310 1.8 110 2.8 5 000 3 18 Blue + White
9343 4 350 3.1 5 000 4 24 Pink + White
9344 4 300 3.1 5 000 2.5 12 Green + White
Pot Life
Cure Time
@25°C
ColourMaterial Code
Thermal
Conductivity
Viscosity
(mixed)
Density
Dielectric
Breakdown Voltage
Material Code Thermal Conductivity Flow Rate Density
Dielectric
Breakdown Voltage
Colour
[W/(m·K)] [g/min] [g/cm3] [VAC/mm]
9240 4.5 22 3.2 >5 000 White

31. 8

32. 9
[W/(m·K)] [cP] [g/cm3
] [µm] [K·cm2
/W]
9520 2.5 80 000 2.2 20 0.08 Grey
9521 2 110 000 2.8 20 0.20 White
9522 2.8 225 000 2.8 20 0.08 Grey
9530 3 80 000 2.2 20 0.07 Grey
9540 4.3 300 000 2.3 20 0.06 Grey
9541 4.3 500 000 2.3 20 0.06 Grey
Minimum Achievable
Bondline Thickness
ColourMaterial Code
Thermal
Conductivity
Viscosity Density
Thermal Resistance
@40PSI

33. 10
PCM

34. ► Samples can be provided
Phase-Change Materials
11

35. 12
What Sets Us Apart?
NOLATO USP’s

36. Strong Materials Suite:
► Comprehensive selection
– 20 pad materials
– 6 pastes
– 4 fillers
– PCM
► Advanced materials
– 7, 8, 13.5W/(m·K)
– Ultra-Soft 4W/(m·K)
– High-end fillers
– High performance paste
► Big range of “standard custom”
options
– 0.25mm increment standard
thickness range
– Carriers – PI, aluminium, fibreglass,
etc
– Coatings – non-tacky, adhesive, etc
► Real quality
What Makes COMPATHERM Different?
13

37. Strong Competence:
► Ability to modify & tailor existing materials to specific
requirements on request
► Ability to create new materials and solutions when needed
► Ability to guide customers through materials selection
► Ability to provide thermal design assistance worldwide
► Ability to discuss, analyse, and solve thermal issues at
considerable technical depth
What Makes COMPATHERM Different?
14

38. Good Service:
► Provide samples quickly and conveniently worldwide
► Respond and solve issues quickly
► We have short lead times
What Makes COMPATHERM Different?
15