Stacked memory for flight recorders

• US 5,841,638 A
• Filed: 02/15/1996
• Issued: 11/24/1998
• Est. Priority Date: 02/15/1996
• Status: Expired due to Term

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Inventors: Purdom, Gregory W., Berecz, Endre M.
• Primary Examiner(s): Picard, Leo P.
• Assistant Examiner(s): Vigushin, John B.
• Application Number:
  US08/602,066
• Time in Patent Office: 1,013 Days
• Field of Search: 361/790, 361/803, 361/804, 361/733, 361/735, 361/757, 361/758, 257/686, 439/69, 439/74, 439/76.1, 439/91, 206/521, 206/305
• US Class Current: 361/790
• CPC Class Codes: H05K 1/144 Stacked arrangements of planar printed circuit boards
• CPC Class Codes: H05K 5/021 specially adapted for data recorders, e.g. for flight recorders
• CPC Class Codes: H05K 7/023 Stackable modules
• CPC Class Codes: H05K 7/142 Spacers not being card guides
• CPC Class Codes: H05K 7/1434 for electronics exposed to high gravitational force; Cylindrical housings

Abstract

A stacked memory module having alternating layers of printed circuit boards and spacers. Connections between a given circuit board surface and an adjacent (facing) stacked printed circuit board surface, are made using at least one conductive pad incorporated into the electrical circuitry printed on and within the perimeter of each of the adjacent pair of board surfaces; together with means for interconnecting these conductive pads. The spacers can, for example, take the form of standoffs, spacer boards provided with clearance cutouts for components on the printed circuit boards, etc. The printed circuit boards and spacers are then aligned and fastened together using, for example, one or more alignment rods. According to a preferred embodiment of the invention, the fastened assembly is placed in a hollow memory module housing (e.g., a metal cylinder) to complete the fabrication of the memory module. Other aspects of the invention are directed to flight recorders per se which incorporate the above described memory module; and to processes for fabricating both the above described memory module and flight recorders containing such memory modules.

Claims

1. A flight recorder comprising:

(a) a crash housing;

(b) A memory module located within said crash housing including;

(b1) a stacked plurality of printed circuit boards at least one of which has at least one memory device on at least one board surface;

(b2) at least one conductive pad incorporated into electrical circuitry printed on and within the perimeter of each of an adjacent pair of board surfaces;

(b3) means for interconnecting conductive pads located on and within the perimeter of an adjacent pair of board surfaces;

(b4) spacer means for separating and supporting said stacked plurality of printed circuit boards;

(b5) alignment means for registering conductive pads located on adjacent pairs of printed circuit boards; and

(b6) means for fastening together said stacked plurality of printed circuit boards and said spacer means;

(c) thermal insulation for protecting said memory module from heat, wherein no flammable foam is located between adjacent pairs of printed circuit boards; and

(d) means for coupling electrical signals between an external source and said at least one memory device, said means for coupling further comprising;

(d1) means for communicating electrical signals between said external source and said at least one memory device via a connector means to which said means for communicating is attached; and

(d2) a locking mechanism for securing said means for communicating to said connector means.

2. A method for fabricating a memory module for storing digital information, comprising the steps of:

(a) forming at least one conductive pad in electrical circuitry printed on and within the perimeter of a first surface of a first printed circuit board, wherein said first printed circuit board includes at least one memory device on at least one surface thereof;

(b) forming at least one conductive pad in electrical circuitry printed on and within the perimeter of a first surface of a second printed circuit board, wherein said first surface of said first printed circuit board faces said first surface of said second printed circuit board when said first printed circuit board and said second printed circuit board are placed together in a component stack;

(c) stacking said first printed circuit board and said second printed circuit board together in a component stack that includes means for separating and supporting said first printed circuit board and said second printed circuit board and means for interconnecting conductive pads located on and within the perimeter of said first surface of said first printed circuit board and said first surface of said second printed circuit board;

(d) registering the conductive pads in said component stack;

(e) fastening together the components of said component stack, wherein no flammable foam is located between adjacent pairs of printed circuit boards; and

(f) coating the printed circuit boards in said component stack with a uniform coating of PARYLENE.

3. A method for fabricating a memory module for storing digital information, comprising the steps of:

(a) stacking a plurality of printed circuit boards at least one of which has at least one memory device on at least one board surface;

(b) forming at least one conductive pad in electrical circuitry printed on and within the perimeter of each of an adjacent pair of board surfaces;

(c) interconnecting conductive pads located on and within the perimeter of an adjacent pair of board surfaces;

(d) separating and supporting the stacked plurality of printed circuit boards utilizing spacer means;

(e) registering conductive pads located on adjacent pairs of printed circuit boards; and

(f) fastening together the stacked plurality of printed circuit boards as separated by said spacer means, wherein no flammable foam is located between adjacent pairs of printed circuit boards; and

(g) coating the printed circuit boards in said component stack with a uniform coating of PARYLENE.