Pin-fin heat sink

• US 5,299,090 A
• Filed: 06/29/1993
• Issued: 03/29/1994
• Est. Priority Date: 06/29/1993
• Status: Expired due to Term

• Current Assignee: American Telephone & Telegraph Company (AT&T, Inc.)
• Original Assignee: AT&T, Inc.
• Inventors: Brady, Kevin J., Cohn, Charles
• Primary Examiner(s): Thompson, Gregory D.
• Application Number:
  US08/085,232
• Time in Patent Office: 273 Days
• Field of Search: 165/80.3, 165/80.4, 165/185, 174/16.3, 257/707, 257/712, 257/713, 257/722, 361/383, 361/384, 361/386-389, 29/890.035, 29/890.054, 29/412
• US Class Current: 361/703
• CPC Class Codes: H01L 23/3677 Wire-like or pin-like cooling fins or heat sinks
• 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: Y10T 29/49393 with metallurgical bonding
• CPC Class Codes: Y10T 29/49789 Obtaining plural product pieces from unitary workpiece

Abstract

A housed integrated circuit unit package is provided with a heat sink for removal and dissipation of heat from electronic circuits housed in packages. The heat sink, mounted on an outer surface of the package, includes a plurality of pins secured at one end with a retainer and flared out at the other end into a starburst or bouquet configuration, the pins being in the form of rods selected from solid cylinders and tubes. The bottom of the retainer-bound end is coated with a securing substance, such as solder or a heat-conducting adhesive, which is planarized to facilitate positioning of the heat sink on the package. The heat sink is secured to the package by means of solder or a heat-conducting adhesive. The heat sink is produced by securing a plurality of elongated rods by retainers placed at intervals corresponding to a height of the heat sink, cutting off said rods adjacent to one side of the retainer, and flaring the rods at the other free end of the cut-off rods into a starburst-like configuration. The retained ends of the rods are dipped into a solder or heat-conducting adhesive and planarized to provide a planar surface for mounting the heat sink on the surface of the package.

Claims

1. An encapsulated device with a heat sink, which comprises;

a housing enclosing an integrated circuit unit, and

said heat sink secured on an outside planar surface of the housing, in which

said heat sink comprises a plurality of elongated pins held at one end within a retainer and having a flared-out star-burst configuration at the opposite end, said pins being of a material having high thermal conductive characteristics, said pins at said one end having a surface planarized by a means of a substance selected from solder or plastic adhesives for mounting said heat sink on said planar surface of the housing.

2. The device of claim 1 in which said pins are in the form of rods selected from solid cylinders and tubes.

3. The device of claim 1 in which said retainer is a ring.

4. The device of claim 1 in which the pins at said one end are further secured within the retainer by securing means selected from solder or plastic adhesive.

5. A method of producing a heat sink comprising a plurality of elongated cylinders held at one end by a retainer and having a flared-out star-burst configuration at the opposite end, which comprises:

placing retainers along a length of a plurality of elongated cylinders, said retainers keeping the cylinders bunched at intervals of predetermined length and said rods being of a material having high thermal characteristics.

cutting the rods into sections, each section including rods of said predetermined length and a retainer,

coating an end surface of each cylinder and an end surface of the retainer with a substance selected from solder or thermally conductive adhesive, and

planarizing coated end surfaces, if needed.

6. The method of claim 5 in which said cylinders are selected from solid rods, pins or tubes.

7. The method of claim 5 in which said retainer is a ring.