Printed circuit board stiffener

• US 6,512,676 B1
• Filed: 07/20/2000
• Issued: 01/28/2003
• Est. Priority Date: 07/20/2000
• Status: Expired due to Fees

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Silicon Graphics Incorporated (Graphics Properties Holdings, Inc.)
• Inventors: Gruber, David Paul, Ruesch, Rodney, Bowen, Stephen A., Cermak, III, Stephen, Cogner, Jeffrey Scott, Crapisi, Thomas Alex, Dobbs, Bonnie Kay
• Primary Examiner(s): Paladini, Albert W.
• Assistant Examiner(s): DINH, TUAN T
• Application Number:
  US09/619,725
• Time in Patent Office: 922 Days
• Field of Search: 361/711, 361/719, 361/720, 361/818, 361/825, 361/752, 361/753, 361/829, 174/252, 174/250, 211/201, 211/41.17, 211/26, 211/189, 312/223.2, 312/265.1
• 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 7/1461 Slidable card holders; Card stiffeners; Control or display means therefor

Abstract

Apparatus and methods for reducing circuit board flexing is presented. The apparatus is fastened to a printed circuit board to provide rigid support for reducing bending and flexing. In one embodiment, a rigid frame is provided that is adapted to be fastened to one or more components and to be fastened to a printed circuit board. The frame is adapted to elevate the attached component from the PCB surface allowing components to be mounted on the PCB therewith. The frame is adapted to occupy minimal printed circuit board surface area so as not to displace electronic components. In another embodiment, an elongated truss-like stiffener is provided that is adapted to be fastened to one side of the printed circuit board and adapted to span the printed circuit board. The elongated stiffener is adapted to have an open structure to minimize cooling flow disturbance and weight. The elongated stiffener includes a plurality of legs forming a truss-like structure. The stiffener supports the printed circuit board to resist bending and flexing stresses. In yet another embodiment, a combination of one or more stiffeners and one or more frames are provided such that the printed circuit board resists bending and flexing stresses.

Claims

1. A printed circuit board stiffener, comprising:

an elongated truss member dimensioned to be mountable to a printed circuit board, the elongated truss member being rigid, the truss member comprising a plurality of legs, the plurality of legs defining apertures, the elongated truss member having a bottom leg defining a fastening surface which runs completely along a bottom surface of the bottom leg such that when the fastening surface of the elongated truss member is mounted flush against a printed circuit board, the fastening surface supports the printed circuit board along the entire length of the elongated truss member to prevent deflection and warping of the printed circuit board; and

fastening means for mounting the truss member in perpendicular relationship to the printed circuit board.

2. The printed circuit board stiffener of claim 1, wherein the plurality of legs define triangular apertures.

3. The printed circuit board stiffener of claim 1, wherein the plurality of legs define rectangular apertures.

4. The printed circuit board stiffener of claim 1, wherein the elongated truss member is electrically insulative.

5. A printed circuit board stiffener, comprising:

a member dimensioned to be mountable to a printed circuit board, the member having a plurality of legs, each leg having a first end and a second end, the plurality of legs rigidly joined end to end in an elongated truss-like configuration having a first side and a second side, the first side and second side being parallel, the first side adapted to be fastened to the printed circuit board, the first side having a fastening surface which runs completely along a bottom surface of the first side such that when the fastening surface of the member is mounted flush against the printed circuit board, the first side supports the printed circuit board along the entire length of the first side to prevent deflection and warping of the printed circuit board; and

fastening means for coupling the first side to the printed circuit board in perpendicular relationship.

6. The printed circuit board stiffener of claim 5, wherein the plurality of legs define a plurality of triangular apertures.

7. The printed circuit-board stiffener of claim 5, wherein the plurality of legs define a plurality of rectangular apertures.

8. A method of stiffening a printed circuit board, the method comprising:

mounting an elongated truss member having a plurality of rigid legs defining a plurality of apertures to a surface of the printed circuit board such that the elongated truss member is substantially perpendicular relative to the surface of the printed circuit board, wherein the elongated truss member includes a bottom leg defining a fastening surface which runs completely along a bottom surface of the bottom leg such that when the fastening surface of the elongated truss member is mounted flush against the printed circuit board, the fastening surface supports the printed circuit board along the entire length of the elongated truss member to prevent deflection and warping of the printed circuit board.

9. The method of claim 8, wherein mounting an elongated truss member to the surface of the printed surface board includes mounting the elongated truss such that the elongated truss substantially spans a length of the printed circuit board.

10. The method of claim 8, further comprising mounting a plurality of elongated trusses to the surface of the printed circuit board such that the plurality of elongated trusses are in a parallel relationship with each other.