Glass substrate and capacitance-type pressure sensor using the same

• US 20060001128A1
• Filed: 06/27/2005
• Published: 01/05/2006
• Est. Priority Date: 07/02/2004
• Status: Active Grant

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Takahashi, Koichi, Murata, Shinji, Hatanai, Takashi, Tamura, Manabu, Soejima, Kazuhiro, Abe, Munemitsu
• Granted Patent: US 7,535,096 B2
• Time in Patent Office: Days
• US Class Current: 257/644
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm

Abstract

A glass substrate has a pair of main surfaces opposite to each other. Two island-shaped portions made of silicon are buried in the glass substrate. The tow island-shaped portions are exposed from the two main surfaces of the glass substrate, respectively. An electrode is formed on one main surface of the glass substrate so as to be electrically connected to one exposed portion of one island-shaped portion, and another electrode is formed thereon so as to be electrically connected to one exposed portion of the other island-shaped portion. Still another electrode is formed on the other main surface of the glass substrate so as to be electrically connected to the other exposed portion of the one island-shaped portion. A silicon substrate having a pressure sensing diaphragm is bonded to the other main surface of the glass substrate.

Claims

1. A glass substrate comprising:

a glass substrate body that has a pair of main surfaces opposite to each other; and

island-shaped silicon portions that are buried in the glass substrate such that at least portions thereof are exposed from the pair of main surfaces, respectively.

2. The glass substrate according to claim 1,

wherein the island-shaped silicon portions are electrically connected to each other by a silicon layer formed on one main-surface of the glass substrate body.

3. The glass substrate according to claim 1,

wherein the island-shaped silicon portions have metal layers buried therein so as to be exposed from at least one of the main surfaces of the glass substrate body, respectively.

4. The glass substrate according to claim 1,

wherein interfaces between the glass substrate and the island-shaped portions have Si—

Si bonding or Si—

O bonding.

5. A capacitance-type pressure sensor comprising:

the glass substrate according to claim 1;

electrodes that are formed on the main surface of the glass substrate from which the island-shaped silicon portions are exposed, and that are electrically connected to the island-shaped silicon portions, respectively; and

a silicon substrate that is provided on one of the main surfaces of the glass substrate having the electrodes formed thereon,

wherein the silicon substrate includes a pressure sensing diaphragm that is separated from the electrode at a predetermined gap and that is deformed by pressure to be measured, and

a variation in capacitance between the electrode and the pressure sensing diaphragm is measured as a pressure variation.

6. A glass substrate manufacturing method comprising:

forming island-shaped portions on a surface of a silicon substrate;

pressing the island-shaped portions against a glass substrate while applying heat to bond the silicon substrate and the glass substrate; and

polishing the surface of the glass substrate to expose the island-shaped portions from the surface of the glass substrate.

7. The glass substrate manufacturing method according to claim 6,

wherein the island-shaped portions are obtained by forming a mask on the surface of the silicon substrate and by performing a sand blast process on the silicon substrate having the mask formed thereon.

8. The glass substrate manufacturing method according to claim 6,

wherein the island-shaped portions are formed by half-dicing the surface of the silicon substrate.

9. A method of manufacturing a capacitance-type pressure sensor comprising:

manufacturing a glass substrate by the method according to claim 6;

forming electrodes on the glass substrate so as to be electrically connected to the island-shaped portions that are exposed from the glass substrate, respectively; and

bonding, to the glass substrate, a silicon substrate having a pressure sensing diaphragm that is deformed by pressure to be measure such that the pressure sensing diaphragm is separated from the electrode at a predetermined gap.