Insulating substrates including through holes

Patent metadata

Field	Value
Publication number	US-9538653-B2
Application number	US-201514855798-A
Country	US
Kind code	B2
Filing date	Sep 16, 2015
Priority date	Feb 26, 2014
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

It is provided an insulating substrate including through holes for conductors arranged in the insulating substrate. A thickness of the insulating substrate is 25 to 100 μm, and a diameter of the through hole is 20 to 100 μm. The insulating substrate includes a main body part and exposed regions exposed to the through holes and is composed an alumina sintered body. A relative density of the alumina sintered body is 99.5 percent or higher. The alumina sintered body has a purity of 99.9 percent or higher, and has an average grain size of 3 to 6 μm in said main body part. Alumina grains are plate-shaped in the exposed region and the plate-shaped alumina grains have an average length of 8 to 25 μm.

First claim

The invention claimed is:

1. An insulating substrate including through holes for conductors, said through holes being arranged in said insulating substrate:
wherein a thickness of said insulating substrate is 25 to 100 μm;
wherein a diameter of said through hole is 20 to 100 μm;
wherein said insulating substrate comprises a main body part and exposed regions exposed to said through holes, respectively;
wherein said insulating substrate comprises an alumina sintered body;
wherein a relative density of said alumina sintered body is 99.5 percent or higher;
wherein said alumina sintered body has a purity of 99.9 percent or higher;
wherein said alumina sintered body has an average grain size of 3 to 6 μm in said main body part;
wherein alumina grains of said alumina sintered body are plate-shaped in said exposed region; and
wherein said plate-shaped alumina grain has an average length of 8 to 25 μm.

2. The insulating substrate of claim 1 , wherein said through hole is formed by laser processing.

3. The insulating substrate of claim 1 , wherein said through holes are formed in molding said alumina sintered body.

4. The insulating substrate of claim 1 , wherein 200 to 800 mass ppm of zirconia, 150 to 300 mass ppm of magnesia and 10 to 30 mass ppm of yttria are added to said alumina sintered body as sintering aids.

5. The insulating substrate of claim 1 , wherein said alumina sintered body has a breakdown voltage of 50 kV/mm or higher.

Assignees

• Ngk Insulators Ltd

Inventors

• Takagaki Tatsuro
• Iwasaki Yasunori
• Miyazawa Sugio
• Ide Akiyoshi
• Nakanishi Hirokazu

Classifications

• C04B2235/3244

  Zirconium oxides, zirconates, hafnium oxides, hafnates, or oxide-forming salts thereof · CPC title

• C04B2235/786

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

• H05K1/03

  Use of materials for the substrate · CPC title

• C04B2235/3418

  Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint · CPC title

• C04B2235/3206

  Magnesium oxides or oxide-forming salts thereof · CPC title