Methods of forming power electronic assemblies using metal inverse opal structures and encapsulated-polymer spheres

Patent metadata

Field	Value
Publication number	US-10892206-B2
Application number	US-201916250743-A
Country	US
Kind code	B2
Filing date	Jan 17, 2019
Priority date	Jan 17, 2019
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

A method of forming a bonding assembly that includes positioning a plurality of polymer spheres against an opal structure and placing a substrate against a second major surface of the opal structure. The opal structure includes the first major surface and the second major surface with a plurality of voids defined therebetween. The plurality of polymer spheres encapsulates a solder material disposed therein and contacts the first major surface of the opal structure. The method includes depositing a material within the voids of the opal structure and removing the opal structure to form an inverse opal structure between the first and second major surfaces. The method further includes removing the plurality of polymer spheres to expose the solder material encapsulated therein and placing a semiconductor device onto the inverse opal structure in contact with the solder material.

First claim

What is claimed is:

1. A method of forming a bonding assembly, the method comprising:
positioning a plurality of polymer spheres against an opal structure, the opal structure comprising a first major surface and a second major surface with a plurality of voids defined therebetween, wherein each of the plurality of polymer spheres encapsulates a solder material disposed therein and contacts the first major surface of the opal structure;
placing a substrate against the second major surface of the opal structure;
depositing a material within the voids of the opal structure;
removing the opal structure to form an inverse opal structure between the first and second major surfaces;
removing the plurality of polymer spheres to expose the solder material encapsulated therein; and
placing a semiconductor device onto the inverse opal structure in contact with the solder material.

2. The method of claim 1 , wherein removing the plurality of polymer spheres and the opal structure comprises dissolving the plurality of polymer spheres and the opal structure with a solution.

3. The method of claim 2 , wherein the solution is a hydrofluoric acid solution.

4. The method of claim 2 , wherein dissolving the opal structure with the solution causes a plurality of dimples and a plurality of pores to form the inverse opal structure.

5. The method of claim 1 , wherein the plurality of polymer spheres is positioned against the opal structure after disposing the substrate against the opal structure.

6. The method of claim 1 , wherein disposing the substrate against the opal structure comprises electrodepositing the substrate onto the opal structure.

7. The method of claim 1 , further comprising bonding the semiconductor device to the inverse opal structure by melting the solder material disposed therebetween.

8. The method of claim 1 , wherein the material comprises a metal.

9. The method of claim 1 , wherein the solder material encapsulated within the plurality of polymer spheres is formed of a bonding material that is different than the plurality of polymer spheres.

10. The method of claim 9 , wherein the bonding material comprises tin.

11. The method of claim 1 , further comprising positioning the plurality of polymer spheres around an outer surface of the inverse opal structure.

12. The method of claim 1 , further comprising positioning the plurality of polymer spheres around an outer surface of the opal structure after depositing the semiconductor device onto the opal structure.

13. The method of claim 1 , further comprising disposing the plurality of polymer spheres within the plurality of voids of the opal structure.

14. The method of claim 13 , wherein removing the opal structure and the plurality of polymer spheres comprises forming the inverse opal structure with the solder material disposed therein.

15. A method of forming a power electronic assembly comprising:
attaching a metal substrate to a first surface of an opal structure, the opal structure comprising a plurality of voids defined between the first surface and a second surface;
attaching a plurality of polymer spheres to the second surface of the opal structure, the plurality of polymer spheres encapsulating a solder material disposed therein;
forming an inverse opal structure between the metal substrate and the plurality of polymer spheres by removing the opal structure disposed therebetween;
exposing the solder material from within the plurality of polymer spheres by removing the plurality of polymer spheres; and
securing a non-metal substrate against the inverse opal structure and in contact with the solder material.

16. The method of claim 15 , attaching the non-metal substrate to the inverse opal structure by melting the solder material disposed therebetween.

17. The method of claim 16 , wherein the solder material encapsulated within the plurality of polymer spheres is formed of tin such that melting the solder material comprises liquefying tin between the non-metal substrate and the inverse opal structure.

18. A method for bonding a semiconductor device to a substrate using metal inverse opals, the method comprising:
depositing the substrate onto a first major surface of an opal structure, the opal structure defining a plurality of voids between the first major surface and a second major surface of the opal structure;
receiving a plurality of polymer spheres within at least one of the plurality of voids of the opal structure;
electrodepositing metal within the plurality of voids of the opal structure to bond the substrate to the opal structure;
dissolving the opal structure to provide a metal inverse opal structure secured along the substrate, the metal inverse opal structure defining a plurality of spheres; and
dissolving the plurality of polymer spheres from within the metal inverse opal structure to expose an encapsulated material positioned within the plurality of polymer spheres; and
depositing the semiconductor device onto the metal inverse opal structure to bond the substrate to the semiconductor device.

19. The method of claim 18 , further comprising melting the encapsulated material from within the plurality of spheres of the metal inverse opal structure to secure the semiconductor device to the substrate.

20. The method of claim 18 , wherein the encapsulated material comprises tin.

Assignees

• Toyota Eng & Mfg North America

Inventors

• Joshi Shailesh N

Classifications

• H10W72/20

  Bump connectors, e.g. solder bumps or copper pillars; Dummy bumps; Thermal bumps · CPC title

• H10W40/258

  Metallic materials (H10W40/254, H10W40/257, H10W40/255, H10W40/251, H10W40/253 take precedence) · CPC title

• H10W72/07331

  Connecting techniques · CPC title

• H10W72/07336

  Soldering or alloying · CPC title

• H10W72/073

  of die-attach connectors · CPC title