IGBT and free-wheeling diode combination

• US 6,404,045 B1
• Filed: 10/13/1999
• Issued: 06/11/2002
• Est. Priority Date: 02/01/1996
• Status: Expired due to Term

• Current Assignee: Infineon Technologies Americas Corp. (Infineon Technologies AG)
• Original Assignee: International Rectifier Corporation (Infineon Technologies AG)
• Inventors: Pelly, Brian R.
• Primary Examiner(s): Jackson, Jr., Jerome
• Assistant Examiner(s): Fenty, Jesse A.
• Application Number:
  US09/417,383
• Time in Patent Office: 972 Days
• Field of Search: 257/723, 257/668, 257/691, 257/690, 257/701
• US Class Current: 257/690
• CPC Class Codes: H01L 23/367 Cooling facilitated by shape of device H01L23/38, H01L23/40, H01L23/42, H01L23/44, H01L23/46 take precedence
• CPC Class Codes: H01L 29/7393 Insulated gate bipolar mode transistors, i.e. IGBT; IGT; COMFET
• 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 combination of an IGBT and an antiparallel-connected freewheeling diode in which the IGBT die size is greater than about twice the diode die size. Preferably the diode die size is about 10%-25% of that of the IGBT. The respective die sizes of an IGBT and an antiparallel connected freewheeling diode may be adjusted by the steps of: determining respective initial die sizes for the IGBT and the diode; increasing the IGBT die size from the initial value; and reducing said diode die size from the initial value. The IGBT die size is increased sufficiently to reduce current density, conduction losses and switching losses in the IGBT. The diode die size is reduced sufficiently to reduce the reverse recovery charge of the diode so as to further reduce switching losses in the IGBT, to a minimum size which is sufficient to carry the antiparallel current without substantial overheating. The adjustment of the diode die size is advantageous either independently of, or in combination with, the adjustment of the IGBT die size. These adjustments are capable of reducing the switching energy of the IGBT and diode by about 30%-40% below that of a conventional IGBT-diode combination.

Claims

1. In combination, an IGBT and an antiparallel-connected freewheeling diode for operating at a predetermined operating current, said IGBT and said antiparallel-connected freewheeling diode having respective die size areas,

wherein said die size area of said IGBT is greater than a rated IGBT die size area for said predetermined operating current, and said die size area of said diode is less than a rated diode die size area for said predetermined operating current;

wherein said IGBT has a current density and loss level such that said diode operates at said predetermined operating current without overheating; and

wherein said IGBT and said diode are copackaged on a common bottom plate.

2. A combination as in claim 1, wherein said diode die size area is about 10%-25% of that of said IGBT.

3. A combination as in claim 1, wherein said diode die size area is a minimum size which is sufficient to carry said predetermined operating current to said freewheeling diode without overheating.

4. A combination as in claim 1, wherein said diode die size area is less than half the die size area of said IGBT.