Electrostatic discharge protection device

• US 5,812,357 A
• Filed: 10/11/1996
• Issued: 09/22/1998
• Est. Priority Date: 10/11/1996
• Status: Expired due to Term

• Current Assignee: Intellectual Ventures I LLC (Intellectual Ventures LLC)
• Original Assignee: Polaroid Corporation (PLR IP Holdings LLC)
• Inventors: Johansen, Arnold W., Cronin, David V.
• Primary Examiner(s): Gaffin, Jeffrey A.
• Assistant Examiner(s): Sherry, Michael J.
• Application Number:
  US08/729,142
• Time in Patent Office: 711 Days
• Field of Search: 361/212, 361/220, 361/221, 361/222, 361/91, 324/207.21, 360/113, 360/104, 360/128
• US Class Current: 361/212
• CPC Class Codes: G11B 5/40 Protective measures on heads, e.g. against excessive temperature G11B5/31 takes precedence; protection against wear G11B5/255 ; protective structure of the head: see under structures, e.g. G11B5/3106
• CPC Class Codes: G11B 5/455 Arrangements for functional testing of heads; Measuring arrangements for heads
• CPC Class Codes: H01R 13/6485 Electrostatic discharge protection in general H05F1/00, for electric apparatus H05K9/0067
• CPC Class Codes: H01R 13/7032 making use of a separate bridging element directly cooperating with the terminals

Abstract

An electrostatic discharge protection device is provided for use with a magnetic read/write transducer. The electrostatic discharge protection device electrically interconnects the conductive elements of magnetoresistive (MR) and inductive heads to provide a low-resistance conductive path placing the conductive elements at a substantially equal electrical potential, thus minimizing electrostatic discharge. The electrostatic discharge protection device provides an electrical path between the conductive elements which is manually or automatically removable upon connection to a mating element. The electrostatic protection device has a resilient inward bias to connect electrically conductive elements such that a ground is established between them and is removed automatically upon insertion of the conductive elements into a mating receptacle which is interposed between the conductive elements and the electrostatic discharge protection device.

Claims

1. An electrostatic discharge protection device for selectively inhibiting electrostatic charge accumulation on an electronic device having a conductor comprising a plurality of wires attached thereto wherein each of the wires is terminated with a respective one of a plurality of spaced pads, each pad having a surface, the electrostatic discharge protection device comprising:

a connector adapted to mate with the electrostatic discharge protection device; and

grounding means for providing an electrical connection between the plurality of spaced pads in an operative position and for providing electrical isolation between the plurality of spaced pads in an inoperative position, the grounding means being reversibly actuable from the operative position to the inoperative position by connecting the conductor to the connector such that the connector is mechanically interposed between the grounding means and the spaced pads.

2. The electrostatic discharge protection device according to claim 1 wherein the grounding means comprises:

a base fabricated to be electrically conductive; and

a plurality of legs integral and electrically communicative with the base and extending therefrom, having an inherent resilient bias into the operative position which is attained when the inherent resilient bias of the plurality of legs locks each of the plurality of legs against a surface of a respective one or more of the plurality of spaced pads so as to establish electrical communication among the plurality of spaced pads thus inhibiting electrostatic charge accumulation on the plurality of spaced pads, and attaining the inoperative position when the inherent resilient bias of the plurality of legs is overcome by the connector which disrupts the electrical communication with the plurality of spaced pads thus electrically isolating the plurality of spaced pads.

3. The electrostatic discharge protection device according to claim 2 further comprising a housing having a supporting relationship to the grounding means.

4. The electrostatic discharge protection device according to claim 3 wherein the base has an extension extending therefrom adapted to secure the base to the housing.

5. The electrostatic discharge protection device according to claim 3 wherein the housing is sized to allow the surface of the plurality of spaced pads to extend outwardly beyond the housing such that at least one of the plurality of spaced pads can receive a test probe.

6. The electrostatic discharge protection device according to claim 1 wherein the connector further comprises an elongated slider having an insulative surface, where in the inoperative position the insulative surface is opposed to the surface of the plurality of spaced pads.

7. The electrostatic discharge protection device according to claim 6 wherein the elongated slider is adapted to interface with a test device.

8. The electrostatic discharge protection device according to claim 7 wherein the elongated slider further comprises:

a testing interface which terminates the elongated slider at a distal end and is adapted to mate with the test device; and

a plurality of contacts disposed on the insulative surface and having a spaced-apart relationship corresponding to the plurality of spaced pads, the plurality of contacts being disposed at a proximal end of the elongated slider in electrical communication with the testing interface such that in the inoperative position of the grounding means each of the plurality of spaced pads electrically communicates with a respective one or more of the plurality of contacts, thereby establishing electrically communication between the plurality of spaced pads and the testing interface.

9. The electrostatic discharge protection device according to claim 7 wherein the elongated slider further comprises:

a bottom surface having the electrical connector;

a plurality contacts, spaced apart and being electrically conductive, each of the plurality of spaced pads contacting a respective one or more of the plurality of contacts in the inoperative position; and

a second plurality of spaced pads in electrical communication with the plurality of contacts and being adapted to engage the test device.

10. The electrostatic discharge protection device according to claim 1 wherein each of the wires further comprises a central conductor enclosed within an insulating layer and wherein at least a portion of the insulating layer of the central conductor is exposed, the grounding means being removably actuable into contact with the exposed portion to establish the operative position.

11. The electrostatic discharge protection device according to claim 10 wherein the grounding means is slidable relative to the exposed portion.

12. The electrostatic discharge protection device according to claim 10 wherein the exposed portion is housed within a conductive sheath such that a diameter of the central conductor is effectively increased.

13. The electrostatic discharge protection device according to claim 12 wherein the grounding means comprises:

elastive means for mechanically connecting the conductive sheath of each of the leads such that the leads are biased into electrical isolation to form the inoperative position; and

a slide slidably disposed with respect to the conductive sheath of the leads such the conductive sheath of each of the leads selectively communicate to form the operative position.

14. The electrostatic discharge protection device according to claim 12 wherein the grounding means comprises:

elastive means for biasing the conductive sheath of the leads into electrical communication to form the operative position; and

a comb having insulative extensions protruding therefrom, the comb being movable to interpose the conductive sheaths with the insulative extensions, thus forming the inoperative position.

15. The electrostatic discharge protection device according to claim 1 wherein the connector further comprises a connector nose fabricated of insulative material that interposes the grounding means and the plurality of spaced pads in the inoperative position.

16. The electrostatic discharge protection device according to claim 15 wherein the connector nose is affixed to a printed circuit board.

17. The electrostatic discharge protection device according to claim 1, wherein the electronic device comprises a magnetoresistive head.

18. The electrostatic discharge protection device according to claim 1, wherein the electronic device comprises a semiconductor device.

19. An electrostatic discharge protection system for use with an electronic device having wires connected thereto, where the electronic device has a test mode for connecting the wires to a test device and a connected mode for connecting the wires to a circuit board, the electrostatic discharge protection system comprising:

first shorting means for selectively inhibiting charge accumulation when the electronic device is in the test mode, the first shorting means being movable between an operative position and an inoperative position, the operative position providing shorting of charge accumulation, the inoperative position providing electrical communication to the test device;

first actuation means for selectively moving the first shorting means between the operative position and the inoperative position;

second shorting means for selectively inhibiting charge accumulation when the electronic device is in the connected mode, the second shorting means being movable between an operative position and an inoperative position, the operative position providing shorting of charge accumulation, the inoperative position providing electrical communication to the circuit board; and

second actuation means for selectively moving the second shorting means between the operative position and the inoperative position.

20. The electrostatic discharge protection system according to claim 19 wherein the first actuation means is a paddle board.

21. The electrostatic discharge protection system according to claim 19 wherein the first actuation means is a cam manually actuating the first shorting means.

22. The electrostatic discharge protection system according to claim 19 wherein the second actuation means is a connector on a circuit board.

23. The electrostatic discharge protection system according to claim 19 wherein the second actuation means is a cam for manually actuating the second shorting device.

24. The electrostatic discharge protection system according to claim 19, wherein the electronic device comprises a magnetoresistive head.

25. A method of protecting an electronic device from electrostatic discharge damage comprising:

placing a shunt across a connector having a plurality of conductive pads disposed thereon such that each of the plurality of pads is electrically connected; and

establishing electrical isolation of the plurality of pads prior to use of the electronic device by reversibly interposing a slider between the shunt and the plurality of pads.

26. The method according to claim 25, wherein the electronic device comprises a magnetoresistive head.

27. The method according to claim 25, wherein the electronic device comprises a semiconductor device.

28. A method of protecting an electronic device from electrostatic discharge damage, the electronic device having wires connected thereto, where the electronic device has a test mode for connecting the wires to a test device and a connected mode for connecting the wires to a circuit board, the method comprising:

placing first shorting means across the wires for selectively inhibiting charge accumulation when the electronic device is in the test mode, the first shorting means being reversibly movable between an operative position and an inoperative position, the operative position providing shorting of charge accumulation, the inoperative position providing electrical communication to the test device; and

placing second shorting means for selectively inhibiting charge accumulation when the electronic device is in the connected mode, the second shorting means being reversibly movable between an operative position and an inoperative position, the operative position providing shorting of charge accumulation, the inoperative position providing electrical communication to the circuit board.

29. The method according to claim 28, wherein the electronic device comprises a magnetoresistive head.

30. An electrostatic discharge protection system for selectively inhibiting electrostatic discharge on an electronic device having wires selectively connected thereto, wherein each of the wires is electrically terminated with a respective one of a plurality of spaced pads, each pad having a surface, the electrostatic discharge protection system comprising:

a base fabricated from a conductive material;

a housing having a supporting relationship to the base;

at least one leg having a inherent resilient bias, the at least one leg integral with the base and extending therefrom and forming in conjunction with the base a grounding means, the grounding means having an operative position and an inoperative position, the operative position being attained when the inherent resilient bias of the at least one leg locks the at least one leg against the surface of one or more of the plurality of spaced pads, the one or more of the plurality of spaced pads in electrical communication with the base thus inhibiting electrostatic charge accumulation on the plurality of spaced pads, the inoperative position being attained when the plurality of spaced pads become electrically isolated from the base, disrupting the electrical communication with the plurality of spaced pads; and

actuation means disposed on the housing for selectively reversibly moving the grounding means between the inoperative position and the operative position thus selectively inhibiting electrostatic charge accumulation.

31. The electrostatic discharge protection system according to claim 30 wherein the actuation means is a cam.

32. The electrostatic discharge protection system according to claim 31 wherein the cam is manually actuable to shift the grounding means between operative and inoperative positions.

33. The electrostatic discharge protection system according to claim 31 wherein the cam is automatically actuable through mechanical contact with the connector to shift the grounding means between operative and inoperative positions.

34. The electrostatic discharge protection system according to claim 30 wherein the actuation means comprises:

a plunger disposed on the housing and in mechanical communication with the grounding means such that displacement of the housing is translated into displacement of the grounding means; and

elastic means for biasing the plunger to move the grounding means into the operative position where force applied to overcome the bias is translated to movement of the grounding means into the inoperative position.

35. The electrostatic discharge protection system according to claim 30 wherein the actuation means comprises:

a wedge disposed on the housing and in mechanical communication with the grounding means such that displacement of the housing is translated into displacement of the grounding means; and

elastic means for biasing the wedge to move the grounding means into the operative position where force applied to overcome the bias is translated to movement of the grounding means into the inoperative position.

36. The electrostatic discharge protection system according to claim 30 wherein the actuation means is an elongated slider that is replacably and removably insertable between the grounding means and the spaced pads to shift the grounding means between operative and inoperative positions.

37. The electrostatic discharge protection system according to claim 30, wherein the electronic device comprises a magnetoresistive head.

38. The electrostatic discharge protection system according to claim 30, wherein the electronic device comprises a semiconductor device.