Cordierite-based sintered body, method for producing the same, and composite substrate

Patent metadata

Field	Value
Publication number	US-2017275207-A1
Application number	US-201715463251-A
Country	US
Kind code	A1
Filing date	Mar 20, 2017
Priority date	Mar 23, 2016
Publication date	Sep 28, 2017
Grant date	—

Abstract

A cordierite-based sintered body according to the present invention contains cordierite as a main component and silicon nitride or silicon carbide. The cordierite-based sintered body preferably has a thermal expansion coefficient less than 2.4 ppm; ° C. at 40° C. to 400° C., an open porosity of 0.5% or less, and an average grain size of 1 μm or less.

First claim

What is claimed is:

1 . A cordierite-based sintered body containing cordierite as a main component and silicon nitride or silicon carbide, the cordierite-based sintered body having:
a thermal expansion coefficient less than 2.4 ppm/° C. at 40° C. to 400° C., an open porosity of 0.5% or less, and an average grain size of 1 μm or less.

2 . The cordierite-based sintered body according to claim 1 , wherein the number of pores that have a maximum length of 1 μm or more and present in an area of 100 μm×100 μm of a polished surface is 10 or less.

3 . The cordierite-based sintered body according to claim 1 , wherein the cordierite-based sintered body has a Young's modulus of 160 GPa or more.

4 . The cordierite-based sintered body according to claim 1 , wherein the cordierite-based sintered body has a four-point flexural strength of 220 MPa or more.

5 . The cordierite-based sintered body according to claim 1 , wherein a polished surface has a center-line average roughness Ra of 1.5 nm or less.

6 . The cordierite-based sintered body according to claim 1 ,
wherein the cordierite-based sintered body contains silicon nitride, and in the case where a polished surface is subjected to observation of a backscattered electron image and a composition analysis with an SEM and then an area ratio of a cordierite phase to a silicon nitride phase is determined from a contrast ratio of the image and converted to a volume ratio of the sintered body, the cordierite phase is 60% to 90% by volume, and the silicon nitride phase is 10% to 40% by volume.

7 . The cordierite-based sintered body according to claim 1 ,
wherein the cordierite-based sintered body contains silicon carbide, and in the case where a polished surface is subjected to observation of a backscattered electron image and a composition analysis with an SEM and then an area ratio of a cordierite phase to a silicon carbide phase is determined from a contrast ratio of the image and converted to a volume ratio of the sintered body, the cordierite phase is 70% to 90% by volume, and the silicon carbide phase is 10% to 30% by volume.

8 . A method for producing a cordierite-based sintered body comprising the steps of:
(a) preparing a raw-material powder mixture by mixing 60% to 90% by volume of a cordierite powder having an average particle diameter of 0.1 to 1 μm and 10% to 40% by volume of a silicon nitride powder having an average particle diameter of 0.1 to 1 μm in a total amount of 100% by volume or by mixing 70% to 90% by volume of a cordierite powder having an average particle diameter of 0.1 to 1 μm and 10% to 30% by volume of a silicon carbide powder having an average particle diameter of 0.1 to 1 μm in a total amount of 100% by volume; and (b) producing a cordierite-based sintered body by forming the raw material powder mixture into a compact having a predetermined form and subjecting the compact to hot pressing at a pressing pressure of 20 to 300 kgf/cm 2 and a firing temperature of 1350° C. to 1450° C.

9 . A composite substrate in which a functional substrate and a support substrate are bonded,
wherein the support substrate is the cordierite-based sintered body according to claim 1 .

Assignees

• Ngk Insulators Ltd

Inventors

• Isoda Yoshinori
• Suzuki Yoshio
• Inoue Katsuhiro
• Katsuda Yuji

Classifications

• C04B2235/74

  Physical characteristics · CPC title

• C04B2235/3481

  Alkaline earth metal alumino-silicates other than clay, e.g. cordierite, beryl, micas such as margarite, plagioclase feldspars such as anorthite, zeolites such as chabazite · CPC title

• C04B2235/3826

  Silicon carbides · CPC title

• C04B2237/341

  Silica or silicates · CPC title

• C04B2235/5436

  micrometer sized, i.e. from 1 to 100 micron · CPC title