Electronic assembly with one or more heat sinks

Patent metadata

Field	Value
Publication number	US-9860987-B2
Application number	US-201514689528-A
Country	US
Kind code	B2
Filing date	Apr 17, 2015
Priority date	Feb 13, 2015
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

An electronic assembly comprises a semiconductor device that has conductive pads on a semiconductor first side and a metallic region on a semiconductor second side opposite the first side. A lead frame provides respective separate terminals that are electrically and mechanically connected to corresponding conductive pads. A first heat sink comprises a first component having a mating side. A portion of the mating side is directly bonded with the metallic region of the semiconductor device. A circuit board has an opening for receiving the semiconductor device. The lead frame extends outward toward the circuit board or a board first side of the circuit board.

First claim

The following is claimed:

1. An electronic assembly comprising:
a semiconductor device having conductive pads on the semiconductor device first side and a metallic region on the semiconductor device second side opposite the first side, the conductive pads comprising at least one oversized conductive pad among the conductive pads, the at least one oversized conductive pad comprising an output terminal for alternating current;
a substrate comprising a dielectric layer and a conductive traces for providing separate terminals that are electrically and mechanically connected to the conductive pads;
a first heat sink comprising a metallic first component having a mating side, a portion of the mating side directly bonded with the metallic region of the semiconductor device and having an opposite side opposite the mating side; and
a circuit board having an opening, the semiconductor device and a lead frame extending at or outward toward the circuit board first side, the circuit board second side opposite the circuit board first side, a plurality of board conductive pads being on the board first side of the circuit board to align with corresponding terminals of the substrate for electrical connection therewith.

2. The electronic assembly according to claim 1 wherein an auxiliary metallic region comprises a central metallic region on the semiconductor device first side.

3. The electronic assembly according to claim 2 wherein the conductive pads are arranged at or near a perimeter of the semiconductor device outward from the auxiliary metallic region.

4. The electronic assembly according to claim 1 wherein an opposite side of the first heat sink comprises first protrusions for heat dissipation.

5. The electronic assembly according to claim 1 wherein the circuit board conductive pads comprise metallic layers of greater thickness than other conductive traces on the circuit board.

6. The electronic assembly according to claim 1 wherein the circuit board conductive pads comprise copper or copper alloy pours.

7. The electronic assembly according to claim 1 wherein the metallic region and the first component of the heat sink are directly bonded, such as directly fused, brazed or welded to form an electrical and mechanical connection.

8. The electronic assembly according to claim 1 wherein the first heat sink is located at or below the circuit board second side.

9. The electronic assembly according to claim 1 further comprising:
a second heat sink comprising a first member overlying the semiconductor device first side, such that the semiconductor device has thermal pathways for heat transfer or dissipation on both the semiconductor device first side and the semiconductor device second side.

10. The electronic assembly according to claim 9 wherein the second heat sink further comprises:
a second member that mates with the first member to form an interior chamber;
a plurality of second protrusions populating the interior chamber and generally spaced apart from each other;
an inlet and an outlet for communication with the interior chamber to circulate a liquid coolant within the interior chamber.

11. The electronic assembly according to claim 1 wherein the first heat sink comprises:
a second component with a recess, the second component mating with the first component to form an interior volume;
a plurality of first protrusions of the first component populating the interior volume and generally spaced apart from each other; and
an inlet and an outlet for communication with the interior volume to circulate a liquid coolant within the interior volume.

12. The electronic assembly according to claim 11 wherein the first component comprises a lid with the first protrusions extending from one end, where each of the first protrusions comprises a ridge or elevated region that extends outward from a base surface of the lid.

13. The electronic assembly according to claim 1 further comprising a current sensor above a conductive strip on the circuit board.

14. The electronic assembly according to claim 13 wherein the current sensor is surrounded by a metallic shield associated with the circuit board.

15. The electronic assembly according claim 1 wherein the conductive traces of the substrate comprise an output terminal that has an interfacing surface that is bonded to the conductive pads of the semiconductor device and an auxiliary metallic region on the semiconductor device first side.

16. The electronic assembly according to claim 15 wherein the output terminal is connected to a corresponding conductive strip on the circuit board, where the conductive strip has a size to promote secondary heat dissipation from the output terminal.

Assignees

• Deere & Co

Inventors

• Singh Brij N
• Roan Thomas
• Wieland Andrew D
• Clements Neal D

Classifications

• H10W90/401

  characterised by multiple insulating or insulated package substrates, interposers or RDLs · CPC title

• H10W40/237

  attached to additional arrangements for cooling · CPC title

• H10W40/233

  attached to chips · CPC title

• H10W40/47 Primary

  by flowing liquids, e.g. forced water cooling · CPC title

• H05K1/111

  Pads for surface mounting, e.g. lay-out · CPC title