Thermoelectric devices and methods for making the same

• US 6,262,357 B1
• Filed: 04/05/2000
• Issued: 07/17/2001
• Est. Priority Date: 08/27/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Dwyer, Scott R., Casey, Jon A., Prettyman, Kevin M., Long, David C., Johnson, Gregory M.
• Primary Examiner(s): Gorgos, Kathryn
• Assistant Examiner(s): Parsons, Thomas H
• Application Number:
  US09/543,269
• Time in Patent Office: 468 Days
• Field of Search: 136/203, 136/205, 136/204, 136/242
• US Class Current: 136/203
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 23/38 Cooling arrangements using the Peltier effect
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H10N 10/17 characterised by the structure or configuration of the cell or thermocouple forming the device

Abstract

Thermoelectric devices having enhanced thermal characteristics are fabricated using multilayer ceramic (MLC) technology methods. Aluminum nitride faceplates with embedded electrical connections provide the electrical series configuration for alternating dissimilar semiconducting materials. Embedded electrical connections are formed by vias and lines in the faceplate. Methods for forming tunnels through lamination and etching are employed. A portion of the dissimilar materials are then melted within the tunnels to form a bond. Thermal conductivity of the faceplate is enhanced by adding electrically isolated vias to one surface, filled with high thermal conductivity metal paste. A low thermal conductivity material is also introduced between the two high thermal conductivity material faceplates.

Alternating semiconducting materials are introduced within the varying thermal conductivity layers by punching vias within greensheets of predetermined thermal conductivity and filling with n-type and p-type paste. Alternating semiconducting materials may also be patterned in linear or radial fanout patterns through screening techniques and lamination of wire structures. A liquid channel within the faceplate is used to enhance thermal energy transfer.

Thermoelectric devices are physically incorporated within the IC package using MLC technology.

Claims

1. A thermoelectric device comprising:

a heat sink;

a plurality of blocks of two different materials arranged thermally in parallel, electrically in series;

a lower plate of high thermal conductivity, having a top surface, a bottom surface, and a plurality of electrically conductive connectors forming electrical connections for said plurality of blocks on the lower plate top surface;

a high thermal conductivity ceramic block attached directly to said plurality of blocks of at least two different materials; and

,

a plurality of channels within said ceramic block containing liquid therein for heat absorption.

2. The thermoelectric device of claim 1 wherein said ceramic block serves as a substrate for said thermoelectric device.

3. The thermoelectric device of claim 1 wherein said ceramic block comprises an aluminum nitride ceramic.

4. The thermoelectric device of claim 3 wherein said aluminum nitride ceramic further comprises a protective oxide layer.

5. A thermoelectric device comprising:

an integrated circuit microchip;

an electronic package, having an upper surface and a lower surface, comprising high thermal conductivity ceramic and conductive wires, such that when said package lower surface is attached to said integrated circuit microchip it functions as a conduction plate;

a plurality of blocks of at least two different materials arranged thermally in parallel and electrically in series;

means for electrically connecting one end of said plurality of blocks on said package upper surface;

a faceplate having embedded lines and vias for electrically connecting the other end of said plurality of blocks;

means for electrically connecting said microchip to said package; and

,

a heat sink attached to said plurality of blocks opposite said package.

6. The thermoelectric device of claim 5 further comprising an aluminum nitride faceplate.

7. The thermoelectric device of claim 5 wherein said plurality of blocks comprise lines alternating semiconducting materials.

8. The thermoelectric device of claim 5 wherein said plurality of blocks comprise alternating semiconducting materials in a radial fanout pattern.

9. The thermoelectric device of claim 8 wherein said plurality of blocks comprise a stack of alternating semiconducting materials in a radial fanout pattern.

10. The thermoelectric device of claim 5 wherein said means for electrically connecting said microchip comprise wirebond connectors.

11. The thermoelectric device of claim 5 wherein said means for electrically connecting said microchip comprise C4 connectors.