Ignitor with printed electrostatic discharge spark gap

• US 6,467,414 B1
• Filed: 06/29/2001
• Issued: 10/22/2002
• Est. Priority Date: 06/29/2001
• Status: Expired due to Term

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Breed Automotive Technology, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Fisher, John C.
• Primary Examiner(s): Carone, Michael J.
• Assistant Examiner(s): BLACKNER, HENRY A
• Application Number:
  US09/895,762
• Time in Patent Office: 480 Days
• Field of Search: 102/202.1, 102/202.2, 102/202.8, 102/202.9
• US Class Current: 102/202.4
• CPC Class Codes: F42B 3/121 Initiators with incorporated integrated circuit
• CPC Class Codes: F42B 3/18 Safety initiators resistant to premature firing by static electricity or stray currents
• CPC Class Codes: F42B 3/182 having shunting means F42B3/185 takes precedence; details of shunting devices H01R13/7032
• CPC Class Codes: H05K 1/026 Spark gaps

Abstract

An ignitor has an outer metal can containing a quantity of reactive material for initiating a pyrotechnic material. A circuit board has a first side that is in contact with the reactive material and a second side that is isolated from the reactive material. A metal structure adjacent the circuit board is well grounded. At least two electrical pins are electrically connected to first electrical traces formed on the second side of the circuit board. Electrical discharge gaps are formed by second electrical traces extending from the first electrical traces to form sharp points which extend to within less than about 0.127 mm of a conductive path to ground.

Claims

1. An ignitor comprising:

an outer metal can containing a quantity of reactive material for initiating a pyrotechnic material;

a circuit board having a first side in contact with the reactive material and a second side that is isolated from the reactive material;

a metal structure adjacent the circuit board which is well grounded;

at least two electrical pins, each electrical pin being electrically connected to first electrical traces formed on the second side of the circuit board;

electrostatic discharge spark gaps comprising second electrical traces extending from the first electrical traces to form sharp points which extend to within less than about 0.127 mm of a conductive path to ground.

2. The ignitor of claim 1 wherein the sharp points extend to within less than about 0.127 mm of the metal structure adjacent the circuit board.

3. The ignitor of claim 2 further comprising third electrical traces having sharp point located less than about 0.127 mm from the sharp points of said second electrical traces, said third electrical traces being in conductive communication with said metal structure adjacent the circuit board.

4. The ignitor of claim 1 wherein the sharp points have a radius of curvature of less than about 0.05 mm.

5. The ignitor of claim 1 wherein the sharp points extend to within less than about 0.076 mm of the conductive path to ground.

6. The ignitor of claim 1 wherein the sharp points have sides that converge at about 30 degrees.

7. An ignitor comprising:

an outer metal can containing a quantity of reactive material;

a circuit board having a first side in contact with the reactive material and a second side that is isolated from the reactive material on which at least one electrical component is mounted to electrical traces formed on said second side;

a metal structure adjacent the circuit board which is well grounded to the metal can;

at least two electrical pins electrically isolated from the outer metal can, each electrical pin being electrically connected to a first electrical trace formed on the second side of the circuit board

second electrical traces extending from the first electrical traces to form points which extend toward the metal structure adjacent the circuit board to form sharply pointed electrostatic discharge points located less than about 0.127 mm from the metal structure adjacent the circuit board.

8. The ignitor of claim 7 wherein the discharge points extend to within less than about 0.076 mm of the metal structure adjacent the circuit board.

9. The ignitor of claim 7 wherein the discharge points have an electrostatic breakdown voltage of approximately 150 volts.

10. An ignitor comprising:

an outer metal can containing a quantity of reactive material;

a circuit board having a first side in contact with the reactive material and a second side that is isolated from the reactive material on which at least one electrical component is mounted to electrical traces formed on said second side;

a metal structure adjacent the circuit board which is well grounded to the metal can;

at least two electrical pins electrically isolated from the outer metal can, each electrical pin being electrically connected to a first electrical trace formed on the second side of the circuit board

second electrical traces extending from the first electrical traces to form points which extend toward the metal structure adjacent the circuit board to form sharply pointed electrostatic sharp discharge points;

third electrical traces having sharp points located less than about 0.127 mm from the sharp points of said second electrical traces, said third electrical traces being in conductive communication with said metal structure adjacent the circuit board.

11. The ignitor of claim 10 wherein the sharp points of the third electrical traces are located less than about 0.127 mm from the sharp points of said second electrical traces.

12. The ignitor of claim 10 wherein the discharge points have an electrostatic breakdown voltage of approximately 150 volts.