A method of fabricating an electronic power module by additive manufacturing, and associated substrate and module

Patent metadata

Field	Value
Publication number	US-2019358285-A1
Application number	US-201816478326-A
Country	US
Kind code	A1
Filing date	Jan 5, 2018
Priority date	Dec 5, 2016
Publication date	Nov 28, 2019
Grant date	—

Abstract

A method of fabricating an electronic power module by additive manufacturing, the electronic module including a substrate having an electrically insulating plate presenting opposite first and second faces, with a first metal layer arranged directly on the first face of the insulating plate, and a second metal layer arranged directly on the second face of the insulating plate. At least one of the metal layers is made by a step of depositing a thin layer of copper and a step of annealing the metal layer, and the method further includes a step of forming at least one thermomechanical transition layer on at least one of the first and second metal layers, the at least one thermomechanical transition layer including a material presenting a coefficient of thermal expansion that is less than that of the metal of the metal layer.

First claim

1 . A method of fabricating an electronic power module by additive manufacturing, the electronic module comprising a substrate having an electrically insulating plate presenting opposite first and second faces, with a first metal layer arranged directly on the first face of the insulating plate and a second metal layer arranged directly on the second face of the insulating plate;
at least one of the metal layers being made by a step of depositing a thin layer of copper and a step of annealing the metal layer; and the method further comprising a step of forming at least one thermomechanical transition layer on at least one of the first and second metal layers, said at least one thermomechanical transition layer comprising a material presenting a coefficient of thermal expansion that is less than that of the metal of the metal layer.

2 . The method according to claim 1 , wherein said at least one thermomechanical transition layer is deposited by depositing a powder bed of material or by spraying powder material, the deposited powder being set by scanning with a heat power source in an inert atmosphere.

3 . A The method according to claim 1 , wherein the coefficients of thermal expansion of the materials used for the thermomechanical transition lie in the range 3 ppm/° C. to 17 ppm/° C.

4 . A The method according to claim 1 , wherein the substrate comprises, on at least one of the first and second faces of the insulating plate, a stack of a metal layer and a plurality of thermomechanical transition layers, with said at least one stack presenting a gradient in its coefficient of thermal expansion.

5 . The method according to claim 1 , further comprising a step of forming a radiator by additive manufacturing from the last thermomechanical transition layer of the second face of the substrate.

6 . The method according to claim 1 , further comprising a step of making a package suitable for protecting the electronic components that are to be mounted on the first face of the substrate and of making connections suitable for electrically connecting the electronic module to external electrical elements, the package and the connections being made by additive manufacturing from the last thermomechanical transition layer of the first face of the substrate.

7 . A substrate for an electronic power module, the substrate comprising an electrically insulating plate presenting opposite first and second faces, with a first metal layer arranged directly on the first face of the insulating plate, and a second metal layer arranged directly on the second face of the insulating plate;
wherein the substrate comprises, on at least one of the first and second metal layers, at least one thermomechanical transition layer comprising a material presenting a coefficient of thermal expansion less than the coefficient of thermal expansion of the metal of the metal layer, and at least one stack of a metal layer and a plurality of thermomechanical transition layers, said at least one stack presenting a gradient in its coefficient of thermal expansion.

8 . The substrate according to claim 7 , wherein the coefficients of thermal expansion of the materials used for the thermomechanical transition layers lie in the range 3 ppm/° C. to 17 ppm/° C.

9 . An electronic power module comprising a substrate presenting a first face and a second face opposite from the first face, and a radiator mounted on the second face of the substrate, the first face of the substrate being for receiving electronic components, wherein the substrate is a substrate according to claim 7 .

10 . The electronic power module according to claim 9 , wherein the radiator comprises the last thermomechanical transition layer of the second face of the substrate, the radiator being made by additive manufacturing from the last thermomechanical transition layer of the second face of the substrate.

11 . The electronic power module according to claim 9 , further comprising a package suitable for protecting the electronic components mounted on the first face of the substrate, the package being made by additive manufacturing from the last thermomechanical transition layer of the first face of the substrate.

Assignees

• Safran

Inventors

• Khazaka Rabih
• Azzopardi Stéphane
• Martineau Donatien Henri Edouard

Classifications

• H10W70/461

  specially adapted for cooling · CPC title

• H10W70/417

  Bonding materials between chips and die pads · CPC title

• H10W72/075

  of bond wires · CPC title

• H10W72/073

  of die-attach connectors · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title