M. Cermak, Natural graphite sheet heat sinks for power...

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1 mm 100 μm

10 μm1 mm

2) Exfoliated natural graphite (ENG) particles

Layered graphite structure

Cell wall (~60 graphite layers)

0.3354 nm

1) Natural graphite flakes

Flake face

Flake edge

Simplified structure illustration

M. Cermak, Natural graphite sheet heat sinks for power electronics, PhD thesis, Simon Fraser University, 2020Appendix A

Forming of natural graphite sheet

4) Natural graphite sheet (NGS)

3) Compression forming

0.5 0.75 1 1.25 1.5 1.75

- Free-standing density [g cm-3]

0

5

10

15

20

25

30

35

-F

orm

ing

pre

ssur

e [M

Pa]

A

0.5 0.75 1 1.25 1.5 1.75

1

2

3

4

5

-F

ree

-sta

ndin

g th

ickn

ess

[mm

]

0.05 g cm-2

0.10 g cm -2

0.15 g cm -2

0.20 g cm -2

0.25 g cm-2

[g cm-2]

1 cm

1 cm

Mass of ENG particles

Area of sheet

Surface density

1) Determine desired free-standing density based on considered application and NGS properties in Appendix B2) Determine desired free-standing thickness [mm]3} Calculate (or estimate graphically) surface density:4) Calculate the mass of ENG particles:5) Compress ENG particles at forming pressure:

Compressiondirection

- Free-standing density [g cm-3]

Recommended design and manufacturing process: