Heat sink with parallel flat faces

• US 4,012,769 A
• Filed: 08/04/1975
• Issued: 03/15/1977
• Est. Priority Date: 08/04/1975
• Status: Expired due to Term

• Current Assignee: Thermalloy, Inc. (Ansys Incorporated)
• Original Assignee: Thermalloy, Inc. (Ansys Incorporated)
• Inventors: Edwards, Steven F., Pritchett, James D.
• Primary Examiner(s): James, Andrew J.
• Application Number:
  US05/601,920
• Time in Patent Office: 589 Days
• Field of Search: 357/81, 357/72, 165/80, 165/105, 174/16 HS
• US Class Current: 257/718
• CPC Class Codes: H01L 23/3672 Foil-like cooling fins or heat sinks being part of lead-frames H01L23/49568
• CPC Class Codes: H01L 23/4093 Snap-on arrangements, e.g. clips
• 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

Disclosed is a unitary heat sink apparatus for dissipating thermal energy generated by semiconductor devices encapsulated in an encapsulation device of the JEDEC TO-202 or Motorola Case 152 device case style. The heat sink is a unitary sheet metal device folded to form two opposed end plates joined by a central barrel portion which acts as a spring to urge the opposed faces of the end plates together. The thermal conductor tab extending from the encapsulation device is held between the opposed faces of the end plates.

Claims

1. Unitary heat sink apparatus comprising a substantially cylindrical body of thermally conductive material having a pair of mutually opposed substantially flat members extending radially outwardly from said cylindrical body, the opposed faces of said radially extending members being resiliently urged into mutual contact by the substantially cylindrical body, each of said opposed faces having a notch therein, said notches lying in register and defining an open-ended space for receiving the body of a semiconductor encapsulation device having a central body with leads extending from one end of said body and a thermal conductor tab extending from the opposite end of said body when said thermal conductor tab is grippingly held between said opposed faces, the sides of said flat members defining said notches extending along opposite sides of said central body to retain said central body within said notches and to act as fins extending into the surrounding environment, at least one of said flat members having the edge thereof at the base of said notch flared outwardly from the opposed flat member.

2. Apparatus as defined in claim 1 wherein the end of each of said flat members at the base of said notches is flared outwardly from the other.

3. Apparatus as defined in claim 1 including a tab extending from one of said flat members into the interior of said cylindrical body.

4. In combination, a semiconductor encapsulation device having a central body, leads extending from one end of said central body, and a thermal conductor tab extending from the opposite end of said central body;

and unitary heat sink apparatus comprising a substantially cylindrical body of thermally conductive material having a pair of mutually opposed substantially flat members extending radially outwardly from said cylindrical body, the opposed faces of said radially extending members having a notch therein lying in register with the other notch, the opposed faces of the bases of said notches being adjacent opposite sides of said thermal conductor tab and being resiliently urged toward each other and into intimate contact with said thermal conductor tab by the said substantially cylindrical body, and the portions of said flat members surrounding said notches extending substantially parallel with each other and with said central body and on opposite sides thereof to retain said central body within said notches and to act as fins extending into the surrounding environment.

5. The combination set forth in claim 4 wherein the base of each of said notches is flared outwardly from said thermal conductor tab.

6. The combination set forth in claim 4 wherein said thermal conductor tab has a hole therein and said heat sink apparatus includes locking means for engaging said hole.

7. The combination set forth in claim 6 wherein said locking means comprises a tab cut from said cylindrical body and extending from one of said flat members into the cavity of said cylindrical body and mating with said hole.