Refractory Metals
Molybdenum Wafer for LED
A light-emitting diode (LED) is a semiconductor device that emits visible light when an electric current passes through it. LEDs are semiconductor crystals and light sources. Depending on the composition of the crystal compounds, they emit light in the colors of red, green, yellow or blue. LED consists of multiple layers of semi-conducting material. The most important core part is LED chip which is typically made of sapphire, SiC or silicon by using an epitaxial process (MOCVD) whereby layers of semiconductor materials are deposited onto the substrates inside a MOCVD reactor.
Our pure molybdenum and MoCu are the ideal materials as carrier wafers for bonding to LED chips, because of their compatible thermal expansion with semiconductor materials and ceramics, high melting point, high thermal conductivity and electrical conductivity.
Molybdenum wafer as heat-sinker for LED chips
● Made of pure molybdenum or MoCu
● Diameter from 2 inches to 8 inches (50.8 mm to 203.2 mm)
● Thickness more than 0.05 mm
● Surface as-rolled, polished or coated by PVD
● Laser cutting or mold-pressed
● Professional packing
● Tolerance, roughness, flatness and properties can be custom designed
Typical thermal properties
Pure Mo - W - MoCu - WCu - Semiconductor materials - Ceramics
Material
Coefficient of
thermal expansion
[ppm/K]
Thermal
conductivity
[W/(m ·K)]
Specific heat
[J/(g·K)]
Density
[g/cm3]
Hardness
[HV]
Young’s Modulus
[GPa]
Mo
5.1
138
0.25
10.2
240
320
85Mo-15Cu
7.0
160
0.28
10.0
150
280
80Mo-20Cu
7.5
175
0.28
9.9
160
250
70Mo-30Cu
8.3
200
0.29
9.8
180
230
60Mo-40Cu
10.2
222
0.31
9.6
170
210
50Mo-50Cu
11.2
260
0.32
9.5
165
180
W
4.5
167
0.13
19.3
370
380
90W-10Cu
6.5
180
0.16
17.0
300
330
85W-15Cu
7.2
190
0.17
16.4
280
310
80W-20Cu
8.3
200
0.18
15.6
260
280
75W-25Cu
9.0
220
0.19
14.9
240
260
Si
3.0
151
0.75
2.3
-
170
GaAs
5.9
46
0.33
5.32
-
90
GaN
a5.6-c3.2
130
0.49
6.15
-
-
SiC
3.1
490
0.69
3.2
-
221
BeO
7.6
251
0.96
2.9
1200
330
Al2O3
6.7
17
0.8
3.6
1900
370
SiO2
3.0
1.4
-
0.7
-
-
