Author Affiliations
11. Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China22. Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, Chinashow less
1. Schematic diagram of power module and metallized ceramic substrate
[7] 2. Appearance of (a) Si
3N
4 coppered substrate after 1000 thermal cycles of -40 to 250 ℃, (b) AlN coppered substrate after 7 cycles of -40 to 250 ℃, and (c) side view of the delaminated Cu plate indicated by white circle in (b)
[9] 3. Microstructure factors affecting the thermal conductivity of Si3N4 ceramics
4. Effect of grain size on the thermal conductivity of
β-Si
3N
4 with various grain-boundary film thicknesses
[35] 5. Thermal conductivity and lattice oxygen content of
β-Si
3N
4 changed by adjusting the ratio of Y
2O
3/SiO
2[18] 6. Relationships between ionic radii of rare-earth oxide additives and (a) thermal conductivity, (b) thermal diffusivity and (c) lattice oxygen content of
β-Si
3N
4[43] 7. Bright-field (BF) TEM images of Si
3N
4 samples
[46] 8. Developments of high thermal conductivity Si3N4 ceramics with different sintering additives systems and sintering methods
9. Change of (a) average grain size, (b) bending strength, (c) fracture toughness, and (d) thermal conductivity of Si
3N
4 ceramics with radius of rare earth ion
[79] 10. Elemental distributions of the polished surface of Si
3N
4 with Gd
2O
3-MgSiN
2 additives after sintering at 1900 ℃ for 12 h
[80] 11. Schematic diagram of the mechanism of sintering additive ZrH
2 in the sintering of Si
3N
4 ceramics
[76] 12. Effect of carbon addition on the microstructure of Si
3N
4 ceramics
[67] 13. Kinetic analysis of
β-Si
3N
4 grain growth in Si
3N
4 samples with Y
2O
3-MgO and YF
3-MgF
2 additives
[88] 14. Relationships between thermal conductivity of Si
3N
4 ceramics prepared by different sintering processes and (a) sintering time, (b) lattice oxygen content and (c) flexural strength
[16,93,94] 15. Schematic diagram of the four different embedding conditions
[95] 16. Effect of different pre-sintering temperature on the microstructure of Si
3N
4 after two-step sintering((a) 1500 ℃, (b) 1525 ℃, (c) 1550 ℃ and (d) 1600 ℃), (e) relative density of Si
3N
4 samples after pre-sintering and two-step sintering, and (f) thermal conductivity and flexural strength of Si
3N
4 samples after two-step sintering
[97] 17. Thermal conductivity, bending strength and fracture toughness of Si3N4 ceramics prepared by different sintering methods and additives
18. Effect of substrate thickness on the dielectric breakdown strength (DBS) of Si
3N
4 ceramics sintered for (a) 1, (b) 3, (c) 6, (d) 12, (e) 24, and (f) 48 h
[117] 19. Schematic images of the connecting path for the interface between
β-Si
3N
4 grain and grain boundary phases/ intergranular glassy films (IGFs) in the substrates which have (a) smaller and (b) larger ratio of grain size to substrate thickness
[117] 20. Images of the SN-1 coppered substrate after different thermal cycles ((a) 10 cycles, (b) 100 cycles, (c) 200 cycles, and (d) 1000 cycles), (e) plots of residual to initial strength ratio
vs. thermal cycle number of the coppered substrates, and (f) relationship between residual to initial strength ratio and fracture toughness of the Si
3N
4 coppered substrates after 10 cycles
[118] Material | Al2O3 | AlN | Si3N4 |
---|
Density/(g·cm-3) | 3.9 | 3.3 | 3.2 | Elasticity modulus/GPa | 370 | 310 | 320 | Bending strength/MPa | 300-400 | 220-310 | 600-750 | Fracture toughness/(MPa·m1/2) | 3.5-4.0 | 3.0-3.5 | 6.5-7.5 | Thermal expansion coefficient/(×10-6, K-1) | 7-8 | 4.6 | 2.7-3.4 | Thermal conductivity/(W·m-1·K-1) | 18-24 | 67-150 | 27-54 | Dielectric strength/(kV·mm-1) | 10-18 | 14-16 | 12-18 | Resistivity/(Ω·m) | >1012 | >1012 | >1012 | Relative permittivity | 9-10 | 6.0-8.5 | 7-9 |
|
Table 1. Properties of Al
2O
3, AlN and Si
3N
4 ceramic substrate materials
[8] Ceramic substrate (Material code)
| Flexural strength/MPa | Fracture toughness/(MPa·m1/2)
| Thermal conductivity/(W·m-1·K-1)
|
---|
Si3N4 (SN-1) | 669±29 | 10.5±0.2 | 140 | Si3N4 (SN-2) | 909±303 | 5.2±0.2 | 21 | Si3N4 (SN-3) | 977±79 | 5.5±0.1 | - | Si3N4 (SN-4) | 604±25 | 8.0±0.4 | 90 | AlN | 461±62 | 3.2±0.2 | 180 |
|
Table 2. Mechanical and thermal properties of Si
3N
4 ceramic substrates and AlN ceramic substrates for thermal cycle testing
[118]