Integrated FET and reflowable thermal fuse switch device

• US 8,854,784 B2
• Filed: 10/28/2011
• Issued: 10/07/2014
• Est. Priority Date: 10/29/2010
• Status: Active Grant

• Current Assignee: Littelfuse France Sas (Littelfuse Incorporated)
• Original Assignee: Tyco Electronics Corporation (TE Connectivity Ltd. (United Kingdom)), Tyco Electronics France SAS (TE Connectivity Ltd. (United Kingdom))
• Inventors: Difulvio, Philippe, Toth, James
• Primary Examiner(s): Nguyen, Danny
• Application Number:
  US13/284,779
• Publication Number:
  US 20120281328A1
• Time in Patent Office: 1,075 Days
• Field of Search: 361/56, 361/93.8, 361/103, 361/104
• US Class Current: 361/103
• CPC Class Codes: H01L 23/62 Protection against overvoltage, e.g. fuses, shunts
• 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

A circuit protection device includes a reflowable thermal fuse that shuts off current to a field-effect transistor if the field-effect transistor is overheating. In particular, the reflowable thermal fuse is integrated with the field-effect transistor to provide greater proximity between the field-effect transistor and the reflowable thermal fuse, thus providing efficient and accurate detection of an overtemperature condition in the field-effect transistor.

Claims

1. A circuit protection device comprising:

a field-effect transistor; and

a reflowable thermal fuse in communication with the field-effect transistor, the reflowable thermal fuse (i) being configured to cut off current flow to the field-effect transistor based on a temperature of the field-effect transistor, (ii) being embedded into the field-effect transistor, and (iii) being capable of being reflowed without opening up the reflowable thermal fuse.

2. The circuit protection device of claim 1, wherein the reflowable thermal fuse is in intimate thermal contact with the field-effect transistor.

3. The circuit protection device of claim 1, further comprising a device package enclosing the reflowable thermal fuse and the field-effect transistor.

4. The circuit protection device of claim 1, further comprising a second field-effect transistor in communication with the reflowable thermal fuse, wherein the reflowable thermal fuse is configured to cut off current flow to the second field-effect transistor based on a temperature of the second field-effect transistor.