Heat sink plate for multiple semi-conductors

• US 5,285,350 A
• Filed: 08/28/1992
• Issued: 02/08/1994
• Est. Priority Date: 08/28/1992
• Status: Expired due to Term

• Current Assignee: Aavid Thermal Products Incorporated (Ansys Incorporated)
• Original Assignee: Aavid Thermal Products Incorporated (Ansys Incorporated)
• Inventors: Villaume, Henry F.
• Primary Examiner(s): Tolin, Gerald P.
• Application Number:
  US07/937,470
• Time in Patent Office: 529 Days
• Field of Search: 257/706, 257/707, 257/712, 257/723, 174/35 R, 174/35 GC, 174/16.1, 165/146, 165/147, 165/185, 165/80.3, 361/382, 361/383, 361/386-389, 361/399, 361/424, 361/689, 361/690, 361/692, 361/704, 361/705, 361/707, 361/709, 361/752, 361/816, 454/1, 454/184
• US Class Current: 361/690
• CPC Class Codes: H01L 23/3672 Foil-like cooling fins or heat sinks being part of lead-frames H01L23/49568
• CPC Class Codes: H01L 23/467 by flowing gases, e.g. air H01L23/473 takes precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 7/20509 Multiple-component heat spreaders; Multi-component heat-conducting support plates; Multi-component non-closed heat-conducting structures

Abstract

A heat sink comprising a thin plate made of a heat conducting material, which plate includes a series of small tapered chimneys extending therethrough, the plate being adapted to fit over and parallel to an entire circuit board, thermally connecting with the semiconductors on the board, the chimneys being spaced inbetween the semiconductors and facilitating natural or forced airflow from the area between the plate and the printed circuit board to the area outside by means of the low pressure drop created by their tapering, the heat sink taking very little vertical space in the electronics package including the printed circuit board while providing effective heat dissipation and shielding from electro-magnetic radiation and/or radio frequency interference for the semiconductors on the board.

Claims

1. A heat sink dissipating heat from one or more semiconductors on a printed circuit board comprising:

a plate having a top surface and a bottom surface,

said plate being made of heat conductive material and having said bottom surface contacting the semiconductors to be cooled,

said plate having at least one chimney means, each said chimney means including a tapered sidewall defining a first opening in said plate and a smaller second opening away from said plate, so as to convect heated air from the area adjacent to said bottom surface of said plate to the area adjacent to said top surface,

attachment means connecting said bottom surface of said plate to the semiconductors so that said plate conducts heat generated by the semiconductors when the semiconductors are in operation, and

connecting means connecting said plate to a printed circuit board.

2. The heat sink of claim 1 wherein said plate is generally rectangular and adapted to extend parallel to a printed circuit board on which the semiconductors are mounted when said plate is in place.

3. The heat sink of claim 2 wherein each said chimney means is disposed at a location on said plate, which location corresponds in general to an open space on the printed circuit board when said heat sink is in place.

4. The heat sink of claim 1 wherein said plate has at least one inspection hole, each adapted to allow viewing of a portion of one of the semiconductors when said heat sink is in place.

5. The heat sink of claim 1 wherein said plate has ridge means on said bottom surface adapted to align said heat sink with the semiconductors.

6. The heat sink of claim 1 wherein said plate has at least one pair of sidewalls.