Heat sink

• US 5,172,756 A
• Filed: 06/21/1991
• Issued: 12/22/1992
• Est. Priority Date: 06/21/1991
• Status: Expired due to Fees

• Current Assignee: Nortel Networks Corporation
• Original Assignee: Northern Telecom Limited (Nortel Networks Corporation)
• Inventors: Jayamanne, D. Anthony R., Cozzi, Agostino, Hall, Stephen S.
• Primary Examiner(s): Flanigan, Allen J.
• Application Number:
  US07/720,216
• Time in Patent Office: 550 Days
• Field of Search: 165/80.3, 174/16.3, 357/81, 361/383, 361/386
• US Class Current: 165/80.3
• CPC Class Codes: H01L 2023/405 heatsink to package
• CPC Class Codes: H01L 2023/4062 heatsink to or through board or cabinet
• CPC Class Codes: H01L 2023/4087 Mounting accessories, interposers, clamping or screwing parts
• CPC Class Codes: H01L 23/4006 with bolts or screws
• 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

Abstract

Mounted on a circuit board in close proximity to nearby circuit components, a novel heat sink is configured to provide unobstructed tool access to one or more heat producing devices attached thereto. The heat sink includes a massive body member fastened to the circuit board, a support member upstanding from the body member and a radiator member formed integrally with both the support and body members for releasing heat to the environment. One or more mounting surfaces form part of the body member and are provided for mechanically attaching the heat producing devices to the heat sink with good thermal contact. Each mounting surface is inclined with respect to the circuit board such that any device attached to a mounting surface is accessible through an open space between the radiator member and the nearest component on the circuit board.

Claims

1. Heat sink apparatus for accessibly mounting heat producing electronic devices having bent leads on a circuit board in close proximity to a plurality of obstructing components mounted thereon, comprising in combination:

a circuit board adapted to mount the components;

a plurality of the heat producing devices; and

a heat sink supportably mounting the devices and comprising,

a body member, said member being longitudinally extended to function as a partition between selected ones of components mounted on the circuit board and having a supporting surface attached to the board;

a radiator member in integral thermal contact with the body member and adapted to function cooperatively therewith as a continuous electrostatic shield between the selected ones of components; and

an inclined mounting surface forming part of the body member on which the devices are mechanically attached in good thermal contact and with the bent leads positioned in substantially vertical registry with corresponding apertures in the board for establishing electrical contact with the circuit thereof, the mounting surface being angularly disposed relative to the supporting surface such that an axis normal to the mounting surface and in registry with individual ones of the devices extends through a space between the radiator member and the nearest obstructing component to provide unobstructed tool access to the devices.

2. A heat sink as claimed in claim 1, further comprising first attachment means for affixing individual ones of the devices to the inclined mounting surface.

3. A heat sink as claimed in claim 2, further comprising second attachment means for securing the body member to the circuit board.

4. A heat sink as claimed in claim 3, wherein the body member comprises a massive block having low thermal resistance.

5. A heat sink as claimed in claim 4, wherein the radiator member comprises an integral support member and a plurality of fins extending outwardly therefrom.

6. A heat sink as claimed in claim 5, wherein the body and radiator members are disposed in a substantially vertical plane with the radiator member being positioned above the body member.

7. A heat sink as claimed in claim 6, wherein the body and radiator members are unitarily formed as an extruded entity.

8. A heat sink as claimed in claim 7, wherein the first attachment means comprises, a first threaded bore in the body member, a first mounting screw adapted to threadedly engage the first threaded bore, and an aperture formed in the device through which the mounting screw extends to affix the device on the inclined mounting surface.

13. A heat sink as claimed in claim 8, wherein the plurality of radiator fins are individually disposed in a set of horizontal planes disposed in spaced vertical relation.

14. A heat sink as claimed in claim 8, wherein the plurality of radiator fins are radially distributed about the upstanding free end of the support member.

15. A heat sink as claimed in claim 8, wherein the second attachment means comprises, a second threaded bore in the body member, and a second mounting screw adapted to threadedly engage the second threaded bore via an aperture formed in the circuit board through which the second mounting screw extends for attaching the heat sink thereto.

9. A heat sink for accessibly mounting a heat producing electronic device on a circuit board in close proximity to at least one obstructing component mounted thereon, comprising in combination:

a body member comprising a massive block having low thermal resistance and a supporting surface for attachment to the circuit board;

a radiator member comprising an integral support member and a plurality of fins extending outwardly therefrom in integral thermal contact with the body member;

first and second inclined mounting surfaces forming part of the body member and disposed back-to-back on opposite sides thereof for mechanically attaching the device to either surface with good thermal contact, each mounting surface being angularly disposed relative to the supporting surface such that an axis normal to either mounting surface and in registry with the device extends through a space between the radiator member and the nearest obstructing component to provide unobstructed tool access to the device;

first attachment means for affixing the device on a selected one of the inclined mounting surfaces; and

second attachment means for securing the body member to the circuit board.

10. A heat sink as claimed in claim 9, wherein the first and second inclined mounting surfaces are set at unequal angles relative to the supporting surface.

11. A heat sink as claimed in claim 9, wherein the first and second inclined mounting surfaces are set at equal angles relative to the supporting surface.

12. A heat sink as claimed in claim 10, wherein the respective angles of the first and second inclined mounting surfaces are set at an angle within the range of from 22°

to 65°

.