Ceramic substrate

• US 8,173,283 B2
• Filed: 11/25/2009
• Issued: 05/08/2012
• Est. Priority Date: 11/27/2008
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Furukawa, Shigenobu
• Primary Examiner(s): Bernatz, Kevin M.
• Assistant Examiner(s): FALASCO, LOUIS V
• Application Number:
  US12/626,518
• Publication Number:
  US 20100136279A1
• Time in Patent Office: 895 Days
• Field of Search: 737/23, 735/79, 735/70, 737/27, 737/26, 737/28, 73/121.2, 73/32.A, 735/76, 73/27, 428/688, 428/421, 428/64.2, 428/848, 428/848.1, 428/848.2, 428/64.1, 428/846.9, 428/704, 430/270.12, 252/520.2, 252/520.1, 252/521.3, 360/99.12, 360/135, 264/642, 264/85, 501/152, 501/153, 501/150, 501/154, 210/490
• US Class Current: 428/846.9
• CPC Class Codes: C04B 2235/3206 Magnesium oxides or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3208 Calcium oxide or oxide-forming salts thereof, e.g. lime
• CPC Class Codes: C04B 2235/3217 Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
• CPC Class Codes: C04B 2235/3225 Yttrium oxide or oxide-forming salts thereof
• CPC Class Codes: C04B 2235/3418 Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
• CPC Class Codes: C04B 2235/383 Alpha silicon carbide
• CPC Class Codes: C04B 2235/3878 Alpha silicon nitrides
• CPC Class Codes: C04B 2235/3895 Non-oxides with a defined oxygen content, e.g. SiOC, TiON
• CPC Class Codes: C04B 2235/5409 expressed by specific surface values
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/5445 submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/656 characterised by specific heating conditions during heat treatment
• CPC Class Codes: C04B 2235/6567 Treatment time
• CPC Class Codes: C04B 2235/661 Multi-step sintering
• CPC Class Codes: C04B 2235/662 Annealing after sintering
• CPC Class Codes: C04B 2235/77 Density
• CPC Class Codes: C04B 2235/94 Products characterised by their shape
• CPC Class Codes: C04B 2235/95 Products characterised by their size, e.g. microceramics
• CPC Class Codes: C04B 2235/96 Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 2235/9638 Tolerance; Dimensional accuracy
• CPC Class Codes: C04B 35/111 : Fine ceramics
• CPC Class Codes: C04B 35/5755 : obtained by gas pressure sintering
• CPC Class Codes: C04B 35/5935 : obtained by gas pressure sintering
• CPC Class Codes: C04B 35/6455 : Hot isostatic pressing
• CPC Class Codes: Y10T 428/21 : Circular sheet or circular blank
• CPC Class Codes: Y10T 428/24479 : including variation in thickness

Abstract

A ceramic substrate according to one aspect of the invention comprises a main surface wherein a diameter of a first imaginary circle inscribed in a circumference of the main surface is represented by C (m), a thickness of the ceramic substrate is represented by h (m), a Poisson ratio of the ceramic substrate is represented by ν, a density of the ceramic substrate is represented by ρ(kg/m³), a Young'"'"'s modulus of the ceramic substrate is represented by E(Pa), a deflection of the ceramic substrate is represented by X (m), the deflection being measured in a condition that the ceramic substrate is supported in a region between the first imaginary circle and a second imaginary circle which is a concentric circle of the first imaginary circle and has a diameter of C-0.01 (m), wherein X≦1.5×(C⁴/h²)×A and A={3×9.807×ρ×(1−ν²)×(5+ν)}/{2⁸×(1+ν)×E} are satisfied.

Claims

1. A composition comprising:

an annealed ceramic substrate including a main surface, the ceramic substrate having been annealed at a temperature of 1250°

C. or more and 1800°

C. or less,

wherein the annealed ceramic substrate comprises a ceramic selected from the group consisting of sintered alumina, sintered silicon carbide, sintered silicon nitride and sintered zirconia,

wherein a diameter of a first imaginary circle inscribed in a circumference of the main surface is represented by C (m), a thickness of the ceramic substrate is represented by h (m), a Poisson ratio of the ceramic substrate is represented by ν

, a density of the ceramic substrate is represented by ρ

(kg/m³), a Young'"'"'s modulus of the ceramic substrate is represented by E(Pa), a deflection in a direction of gravity of the ceramic substrate is represented by X (m), the deflection being measured in a condition that the ceramic substrate is supported in a region between the first imaginary circle and a second imaginary circle which is a concentric circle of the first imaginary circle and has a diameter of C-0.01 (m),

wherein the diameter of the first imaginary circle is 0.203 m or more, the thickness of the ceramic substrate is 0.00034 m or more and 0.00116 m or less, the Young'"'"'s modulus of the ceramic substrate is 200 GPa or more and 430 GPa or less, the Poisson ratio ν

of the ceramic substrate is 0.16 or more and 0.31 or less, the density ρ

of the ceramic substrate is 3.2 g/cm³ or more and 5.6 g/cm³ or less, and

wherein the following equations are satisfied;

X≦

1.5×

(C⁴h²)×

A, wherein

A={3×

9.807×

ρ

×

(1−

ν

²)×

5+ν

)}/{2⁸×

(1+ν

)×

E},

and wherein when the ceramic substrate is freely vibrated in a thickness direction thereof in a condition that the ceramic substrate is supported at an end thereof, a decay time of free vibration of the ceramic substrate is 2 s or less.

2. The composition according to claim 1, wherein the main surface of the ceramic substrate has a circular shape.