SEMICONDUCTOR BRIDGE, IGNITER, AND GAS GENERATOR

• US 20090126592A1
• Filed: 09/05/2006
• Published: 05/21/2009
• Est. Priority Date: 09/07/2005
• Status: Active Grant

• Current Assignee: Nippon Kayaku Company Limited
• Original Assignee: Nippon Kayaku Company Limited
• Inventors: Taguchi, Hiroki, Maeda, Shigeru, Mukunoki, Hirotaka
• Granted Patent: US 8,250,978 B2
• Time in Patent Office: Days
• US Class Current: 102/202.700
• CPC Class Codes: B60R 2021/26029 Ignitors
• CPC Class Codes: B60R 21/26 characterised by the inflation fluid source or means to control inflation fluid flow arrangement or mounting thereof to the vehicle B60R21/20; blasting cartridges for producing gas under pressure in general F42B3/04; initiators or igniters therefor F42B3/10
• CPC Class Codes: C06C 9/00 Chemical contact igniters; Chemical lighters
• CPC Class Codes: F42B 3/13 with semiconductive bridge

Abstract

The invention provides a semiconductor bridge, an igniter, and a gas generator each of which satisfies a high-speed responsiveness required of, for example, an automotive side inflator. The semiconductor bridge includes a bridge part heated by being supplied with a current. The bridge part is disposed on a substrate. The bridge part includes a first layer and an ignition bridge layer. The first layer is formed on the substrate and has insulating properties. The ignition bridge layer serves as a second layer disposed on the first layer. The width of the bridge part at the first layer and the width of the bridge part at the second layer are substantially equal to each other. A space is provided around the bridge part. With this structure, the diffusion of current and heat into the substrate can be restricted to the minimum level, and the ignition time can be quickened as an ignition characteristic. Each of the igniter and the gas generator includes the semiconductor bridge.

Claims

1. A semiconductor bridge comprising:

a bridge part ignited by applying a current, the bridge part including a first layer formed on a substrate and a second layer formed on the first layer, the first layer having insulating properties, the second layer being made of a resistive material;

wherein a width of the bridge part at the first layer and a width of the bridge part at the second layer are substantially equal to each other.

4. The semiconductor bridge according to claim 1 or 2, wherein the first layer has a thermal conductivity of 50 W/m·

K or less and an electrical resistivity of 10⁶ Ω

·

m or more in room temperature.

5. The semiconductor bridge according to claim 1 or 2, wherein the first layer has a thickness of 0.02 microns to 3 microns, and the second layer has a thickness of 0.02 microns to 3 microns.

6. The semiconductor bridge according to claim 1 or 2, wherein the first layer contains SiO₂.

7. The semiconductor bridge according to claim 1 or 2, wherein the second layer contains Ni and Cr.

8. The semiconductor bridge according to claim 1 or 2, wherein the substrate is made of silicon.

9. The semiconductor bridge according to claim 1 or 2, wherein the substrate is made of silicon, and a surface of the substrate is provided with an oxide film,

the first layer consisting of a layer containing SiO₂.

10. An igniter including the semiconductor bridge of claim 1 or 2, the semiconductor bridge serving as an ignition element.

11. A gas generator including the igniter of claim 10.

2. A semiconductor bridge comprising:

a bridge part heated by applying a current and formed on a substrate, the bridge part including a first layer and an ignition bridge layer, the first layer being formed on the substrate and having insulating properties, the ignition bridge layer being formed on the first layer and serving as a second layer;

wherein a width of the bridge part at the first layer and a width of the bridge part at the second layer are substantially equal to each other, and

wherein a side face and an upper face of the bridge part are exposed outwardly.

3. The semiconductor bridge according to claim 2, wherein the bridge part has a two-layer structure.

12. An igniter comprising:

a cup body;

a plurality of electrode pins;

a header with which an opening of the cup body is covered, the header holding the plurality of electrode pins insulated from each other;

the semiconductor bridge of claim 2, the semiconductor bridge being in contact with an ignition compound provided in the cup body, the semiconductor bridge being electrically connected to the electrode pins, the semiconductor bridge being ignited by being supplied with a current from outside through the plurality of electrode pins; and

a capacitor electrically connected to a pair of electrode pins among the plurality of electrode pins at the outside of the cup body, the pair of electrode pins being electrically parallel to the semiconductor bridge.

13. An igniter comprising:

a cup body;

a plurality of electrode pins;

a header with which an opening of the cup body is covered, the header holding the plurality of electrode pins insulated from each other;

the semiconductor bridge of claim 2, the semiconductor bridge being in contact with an ignition compound provided in the cup body, the semiconductor bridge being electrically connected to the electrode pins, the semiconductor bridge being ignited by being supplied with a current from outside through the plurality of electrode pins;

a base provided integrally with a pair of electrode pins among the plurality of electrode pins, the pair of electrode pins being electrically parallel to the semiconductor bridge, the base being disposed outside the cup body and between the pair of electrode pins, the base having high rigidity to maintain a distance between the pair of electrode pins; and

a capacitor positioned on the base and electrically connected to the pair of electrode pins.

14. An igniter comprising:

a cup body;

a plurality of electrode pins;

a header with which an opening of the cup body is covered, the header holding the plurality of electrode pins insulated from each other;

the semiconductor bridge of claim 2, the semiconductor bridge being in contact with an ignition compound provided in the cup body, the semiconductor bridge being electrically connected to the electrode pins, the semiconductor bridge being ignited by being supplied with a current from outside through the plurality of electrode pins;

a flexible base disposed outside the cup body and between a pair of electrode pins among the plurality of electrode pins, the pair of electrode pins being electrically parallel to the semiconductor bridge; and

a capacitor positioned on the base and electrically connected to the pair of electrode pins.

15. A gas generator including the igniter of any one of claims 12 to 14.