Crash-hardened memory device and method of creating the same

• US 20080074854A1
• Filed: 09/21/2007
• Published: 03/27/2008
• Est. Priority Date: 09/25/2006
• Status: Active Grant

• Current Assignee: Appareo Systems LLC (AGCO Corporation)
• Original Assignee: Appareo Systems LLC (AGCO Corporation)
• Inventors: Nystven, Peder Alfred, Batcheller, Barry Douglas, Allen, Robert Michael
• Granted Patent: US 7,616,449 B2
• Time in Patent Office: Days
• US Class Current: 361/752
• CPC Class Codes: H05K 1/0271 Arrangements for reducing stress or warp in rigid printed circuit boards, e.g. caused by loads, vibrations or differences in thermal expansion
• CPC Class Codes: H05K 2201/0909 Preformed cutting or breaking line
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49146 with encapsulating, e.g., potting, etc.

Abstract

A crash-hardened memory device in which only a single electronic component, such as a memory chip, mounted on a small printed circuit board (PCB), is protected against an impact. The portion of the PCB containing the electronic component is wrapped in fire-retardant material and RF shielding tape. The wrapped PCB assembly is placed in a rigid, hardened enclosure which provides an environmental seal for the portion of the PCB containing the electronic component. A portion of the PCB extends outside of the enclosure to allow electrical connections to be made to the electronic component contained inside. A score line is created on the PCB to create an acceptable shear point between the internal and external portions of the PCB in the event of a crash. Threaded fasteners extend through and beyond both enclosure halves to provide a means for mounting the crash-hardened memory device on an external surface.

Claims

1. A crash-hardened memory device, comprising

a printed circuit board assembly, comprising

a printed circuit board, comprising a first portion and a second portion,

at least one electronic component receivably mounted on said first portion of said printed circuit board,

a fire-retardant material placed around said first portion of said printed circuit board and said at least one electronic component, but not around said second portion of said printed circuit board, and

a plurality of connector receptacles on said second portion of said printed circuit board electrically connected to said at least one electronic component on said first portion of said printed circuit board;

a first enclosure half placed on a first side of said printed circuit board assembly;

a second enclosure half, placed on a second side of said printed circuit board assembly and attached to said first enclosure half to form a complete environmental seal around said fire-retardant material and said first portion of said printed circuit board, wherein said second portion of said printed circuit board extends outside of said environmental seal; and

a fastening means to securely attach said first enclosure half to said second enclosure half.

2. The crash-hardened memory device of claim 1 wherein the printed circuit board assembly further comprises a securing means to hold said fire-retardant material in place around said first portion of said printed circuit board.

3. The crash-hardened memory device of claim 2 wherein said securing means is an RF shielding tape.

4. The crash-hardened memory device of claim 1 wherein said at least one electronic component is a solid state memory device.

5. The crash-hardened memory device of claim 1 wherein said at least one electronic component is a microprocessor.

6. The crash-hardened memory device of claim 1 wherein said fastening means comprises a plurality of threaded fastening devices.

7. The crash-hardened memory device of claim 6 wherein at least a portion of said plurality of threaded fastening devices are sized such that they extend beyond the exterior of said first enclosure half and said second enclosure half, whereby the extra length of said at least a portion of said plurality of threaded fastening devices can be used to attach said crash-hardened memory device to an external surface.

8. The crash-hardened memory device of claim 1 wherein said fastening means further comprises an adhesive material placed on the interfacing surfaces of said first enclosure half and said second enclosure half.

9. The crash-hardened memory device of claim 1 wherein said printed circuit board contains a score line placed along the boundary between said first and second portions of said printed circuit board, whereby an impact to the crash-hardened memory device would enable the second portion of said printed circuit board to break away cleanly from said first portion of said printed circuit board along said score line.

10. The crash-hardened memory device of claim 1 further comprising a plurality of dowel pins, wherein said plurality of dowel pins extends from holes in said first enclosure half through said printed circuit board assembly into holes in said second enclosure half, whereby said plurality of dowel pins prevent said circuit board assembly from moving significantly by the dissipation of kinetic energy across said crash-hardened memory device during an impact.

11. A method for creating a crash-hardened memory device, comprising the steps of:

creating a printed circuit board assembly comprising the steps of

creating a printed circuit board comprising a first portion and a second portion, wherein said second portion contains exposed connector receptacles which are electrically connected to said first portion,

mounting at least one electronic component on said first portion of said printed circuit board, and

encapsulating said first portion of said printed circuit board and said at least one electronic component in a fire-retardant material;

placing said printed circuit board assembly in a first enclosure half, wherein said first portion of said printed circuit board is contained within said first enclosure half, and said second portion of said printed circuit board extends outside of said first enclosure half;

placing a second enclosure half on top of said first enclosure half, creating a complete environmental seal around said first portion of said printed circuit board, wherein said second portion of said printed circuit board extends outside said complete environmental seal; and

fastening said first enclosure half to said second enclosure half.

12. The method for creating a crash-hardened memory device of claim 11, wherein said step of creating a printed circuit board assembly further comprises the step of applying a securing means to said fire-retardant material to hold it in place around said first portion of said printed circuit board.

13. The method for creating a crash-hardened memory device of claim 12, wherein said securing means is an RF shielding tape.

14. The method for creating a crash-hardened memory device of claim 11, wherein said step of creating a printed circuit board further comprises the step of creating a score line separating said first portion from said second portion of said printed circuit board.

15. The method for creating a crash-hardened memory device of claim 11, wherein said fastening step comprises inserting a plurality of threaded fastening devices through said first enclosure half and said second enclosure half.

16. The method for creating a crash-hardened memory device of claim 15, wherein at least a portion of said plurality of threaded fastening devices extend beyond said crash-hardened memory device, whereby the extending length of said at least a portion of said plurality of threaded fastening devices can be used to attach said crash-hardened memory device to an external surface.

17. The method for creating a crash-hardened memory device of claim 11 wherein said fastening step further comprises spreading an adhesive material on the interfacing surfaces of said first enclosure half and said second enclosure half.

18. The method for creating a crash-hardened memory device of claim 11 further comprising the step of inserting a plurality of dowel pins, such that said plurality of dowel pins extends from holes in said first enclosure half through said printed circuit board assembly into holes in said second enclosure half, whereby said plurality of dowel pins prevent said circuit board assembly from moving significantly by the dissipation of kinetic energy across said crash-hardened memory device during an impact.