High thermal conductive silicon nitride sintered body, and silicon nitride substrate and silicon nitride circuit board and semiconductor apparatus using the same

Patent metadata

Field	Value
Publication number	US-2018002237-A1
Application number	US-201615545586-A
Country	US
Kind code	A1
Filing date	Jan 19, 2016
Priority date	Jan 23, 2015
Publication date	Jan 4, 2018
Grant date	—

Abstract

The present invention provides a high thermal conductive silicon nitride sintered body having a thermal conductivity of 50 W/m·K or more and a three-point bending strength of 600 MPa or more, wherein when an arbitrary cross section of the silicon nitride sintered body is subjected to XRD analysis and highest peak intensities detected at diffraction angles of 29.3±0.2°, 29.7±0.2°, 27.0±0.2°, and 36.1±0.2° are expressed as I 29.3° , I 29.7° , I 27.0° , and I 36.1° , a peak ratio (I 29.3° )/(I 27.0° +I 36.1° ) satisfies a range of 0.01 to 0.08, and a peak ratio (I 29.7° )/(I 27.0° +I 36.1° ) satisfies a range of 0.02 to 0.16. Due to above configuration, there can be provided a silicon nitride sintered body having a high thermal conductivity of 50 W/m·K or more, and excellence in insulating properties and strength.

First claim

1 . A high thermal conductive silicon nitride sintered body having a thermal conductivity of 50 W/m·K or more and a three-point bending strength of 600 MPa or more, wherein when an arbitrary cross section of the silicon nitride sintered body is subjected to XRD analysis and highest peak intensities detected at diffraction angles of 29.3±0.2°, 29.7±0.2°, 27.0±0.2°, and 36.1±0.2° are expressed as I 29.3° , I 29.7° , I 27.0° , and I 36.1° ,
a peak ratio (I 29.3° )/(I 27.0° +I 36.1° ) satisfies a range of 0.01 to 0.08, and a peak ratio (I 29.7° )/(I 27.0° +I 36.1° ) satisfies a range of 0.02 to 0.16.

2 . The high thermal conductive silicon nitride sintered body according to claim 1 , wherein the I 29.3° and I 29.7° are peaks corresponding to a rare earth element-hafnium-oxygen compound crystal, and the I 27.0° and I 36.1° are peaks corresponding to a β-Si 3 N 4 crystal.

3 . The high thermal conductive silicon nitride sintered body according to claim 2 , wherein the rare earth element-hafnium-oxygen compound crystal comprises two or more types of compound crystals having same constituent elements and different composition ratios.

4 . The high thermal conductive silicon nitride sintered body according to claim 1 , wherein a sum of the peak ratio (I 29.3° )/(I 27.0° +I 36.1° ) and the peak ratio (I 29.7° )/(I 27.0° +I 36.1° ) satisfies a range of 0.03 to 0.20.

5 . The high thermal conductive silicon nitride sintered body according to claim 1 , wherein when a highest peak intensity detected at 34.8±0.2° is expressed as I 34.8° , a peak ratio (I 34.8° )/(I 27.0° +I 36.1° ) is 0.02 or less (including zero).

6 . The high thermal conductive silicon nitride sintered body according to claim 2 , wherein the rare earth element-hafnium-oxygen compound crystal comprises two or more types selected from a Y 1.6 Hf 0.3 O 3 crystal, a Y 0.5 Hf 0.5 O 1.75 crystal, and a Y 0.1 Hf 0.9 O 1.95 crystal.

7 . The high thermal conductive silicon nitride sintered body according to claim 1 , comprising yttrium.

8 . The high thermal conductive silicon nitride sintered body according to claim 1 , wherein a maximum diameter of a grain boundary phase is 10 μm or less in an arbitrary cross section of the silicon nitride sintered body.

9 . The high thermal conductive silicon nitride sintered body according to claim 1 , wherein an average particle diameter of major axes of silicon nitride crystal particles is 1 to 10 μm.

10 . The high thermal conductive silicon nitride sintered body according to claim 1 , wherein a porosity of the sintered body is 3% or less (including zero).

11 . The high thermal conductive silicon nitride sintered body according to claim 1 , wherein when a relative dielectric constant at 50 Hz is expressed as ∈r 50 , and a relative dielectric constant at 1 kHz is expressed as ∈r 1000 , the sintered body satisfies a relation: (∈r 50 −∈r 1000 )/∈r 50 ≦0.1.

12 . A silicon nitride substrate comprising the high thermal conductive silicon nitride sintered body according to claim 1 .

13 . The silicon nitride substrate according to claim 12 , wherein a thickness of the silicon nitride substrate is 0.10 mm or more and 0.70 mm or less.

14 . The silicon nitride substrate according to claim 13 , wherein the thickness of the silicon nitride substrate is 0.10 mm or more and less than 0.30 mm.

15 . The silicon nitride substrate according to claim 12 , wherein a maximum diameter of the major axes of the silicon nitride crystal particles in the high thermal conductive silicon nitride sintered body is 20% or less of the thickness of the silicon nitride substrate.

16 . A silicon nitride circuit board, wherein a metal plate is bonded to the silicon nitride substrate according to claim 12 .

17 . The silicon nitride circuit board according to claim 16 , wherein a plurality of metal plates are bonded to at least one surface of the silicon nitride substrate.

18 . The silicon nitride circuit board according to claim 16 , wherein a thickness of at least one metal plate is 0.70 mm or more.

19 . A semiconductor apparatus, wherein a semiconductor chip is mounted on the silicon nitride circuit board according to claim 16 .

Assignees

• Toshiba Kk
• Toshiba Materials Co Ltd

Inventors

• Aoki Katsuyuki

Classifications

• H10W70/692

  Ceramics or glasses · CPC title

• H10W70/68

  Shapes or dispositions thereof · CPC title

• H10W70/60

  Insulating or insulated package substrates; Interposers; Redistribution layers (leadframes H10W70/40) · CPC title

• H10W40/255

  having a laminate or multilayered structure, e.g. direct bond copper [DBC] ceramic substrates · CPC title

• H10W40/10

  Arrangements for heating · CPC title