Packaged semiconductor device having nanoparticle adhesion layer patterned into zones of electrical conductance and insulation

• US 10,636,679 B2
• Filed: 07/01/2019
• Issued: 04/28/2020
• Est. Priority Date: 12/22/2016
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Cook, Benjamin Stassen, Lin, Yong
• Primary Examiner(s): Kebede, Brook
• Application Number:
  US16/458,558
• Publication Number:
  US 20190371624A1
• Time in Patent Office: 302 Days
• Field of Search: 257666, 638612-617
• CPC Class Codes: H01L 21/565 Moulds
• CPC Class Codes: H01L 2224/16245 the item being metallic
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/83385 Shape, e.g. interlocking features
• CPC Class Codes: H01L 23/3121 a substrate forming part of the encapsulation
• CPC Class Codes: H01L 23/3142 Sealing arrangements between parts, e.g. adhesion promotors
• CPC Class Codes: H01L 23/49582 Metallic layers on lead frames
• CPC Class Codes: H01L 24/16 of an individual bump connector
• CPC Class Codes: H01L 24/32 of an individual layer connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/73 Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/01028 Nickel [Ni]
• CPC Class Codes: H01L 2924/15724 : Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2924/15747 : Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2924/1576 : Iron [Fe] as principal constituent
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/18301 : being an anchoring portion, i.e. mechanical interlocking between the encapsulation resin and another package part

Abstract

A device comprises a substrate and an adhesive nanoparticle layer patterned into zones of electrical conductance and insulation on top of the substrate surface. A diffusion region adjoining the surface comprises an admixture of the nanoparticles in the substrate material. When the nanoparticle layer is patterned from originally all-conductive nanoparticles, the insulating zones are created by selective oxidation; when the nanoparticle layer is patterned from originally all-non-conductive nanoparticles, the conductive zones are created by depositing selectively a volatile reducing agent. A package of insulating material is in touch with the nanoparticle layer and fills any voids in the nanoparticle layer.

Claims

1. A device comprising:

a substrate of a first material;

a nanoparticle layer on top of and in contact with a surface of the substrate;

wherein the nanoparticle layer comprises contiguous zones alternatingly having electrical conductance and electrical insulation; and

a second material making contact with the nanoparticle layer wherein the second-material fills voids in the nanoparticle layer.

2. The device of claim 1 wherein the substrate is a laminated substrate including metallic regions.

3. The device of claim 1 wherein the substrate of the first material is one or more surfaces on a metallic leadframe.

4. The device of claim 3 wherein the first material of the metallic leadframe is selected from a group including copper, copper alloys, aluminum, aluminum alloys, iron-nickel alloys, and Kovar™

.

5. The device of claim 4 wherein the metallic leadframe further includes plated layers selected from a group including nickel, palladium, gold, and tin.

6. The device of claim 1 wherein the zones of electrical conductance include nanoparticles having metallic surfaces, the zones of electrical insulation include nanoparticles having oxidized surfaces, and the mixture of diffused nanoparticles includes metals.

7. The device of claim 6 wherein the nanoparticles having metallic surfaces are selected from a group including metal nanoparticles, metal-coated polymeric nanoparticles, metal-coated ceramic nanoparticles, and metal-coated plastic nanoparticles.

8. The device of claim 1 wherein the zones of electrical conductance include nanoparticles having reduced surfaces, the zones of electrical insulation include nanoparticles having non-conductive surfaces, and the admixture of nanoparticles includes non-conductive molecules.

9. The device of claim 8 wherein the nanoparticles having non-conductive surfaces are selected from a group including metal oxide nanoparticles, polymeric compound nanoparticles, nitrogen compound nanoparticles, and electrically conducting nanoparticles coated with polymerics, oxides, and carbon compounds.

10. The device of claim 1 wherein the second material includes a polymeric compound such as an epoxy-based molding compound.

11. A method for substrate modification comprising:

providing a substrate of a first material, the substrate having a first surface;

depositing onto the first surface a layer including nanoparticles of a second material, wherein the second material is electrically conductive;

sintering together the nanoparticles of the second material;

transmuting the electrical conductance of selected zones of the layer to electrical insulator by selective oxidation; and

encapsulating the nanoparticle layer and as least portions of the substrate in a third material, wherein the third material adheres to at least portions of the nanoparticle layer.

12. The method of claim 11 wherein the second material is selected from a group including metal nanoparticles, metal-coated polymeric nanoparticles, metal-coated ceramic nanoparticles, and metal-coated plastic nanoparticles.

13. The method of claim 11 wherein the selective oxidation employs a selective technique chosen from a group including heating, exposing to oxidizing atmosphere, exposing to oxidizing substances, and depositing a volatile oxidizing agent.

14. The method of claim 11 wherein the selective oxidation by exposing to oxidizing substances employs masking or selective deposition.

15. The method of claim 11 wherein the package of the third material includes a polymeric compound such as an epoxy-based molding compound.

16. A method for substrate modification comprising:

providing a substrate of a first material, the substrate having a first surface;

depositing onto the first surface a layer including nanoparticles of a second ma wherein the second material is electrically non-conductive;

sintering together the nanoparticles of the second material;

transmuting the electrical non-conductance of selected zones of the layer to electrical conductance by selective reduction or ablation; and

encapsulating the layer and at least portions of the substrate in third material wherein the third material adheres to at least portions of the nanoparticle layer.

17. The method of claim 16 wherein the second material is selected from a group including metal oxide nanoparticles, polymeric compound nanoparticles, nitrogen compound nanoparticles, and electrically conducting nanoparticles coated with polymerics, oxides, and carbon compounds.

18. The method of claim 16 wherein the selective reduction or ablation employs a technique chosen from a group including selective exposure to reducing atmosphere, selective deposition of a volatile reducing agent, and selective heating for ablating non-conductive coatings.

19. The method of claim 16 wherein the selective technique includes the use of a mask.

20. The method of claim 16 wherein the third material includes a polymeric compound such as an epoxy-based molding compound.

21. A device comprising:

a substrate of a first material; and

a nanoparticle layer on top of and in contact with a surface of the substrate, the nanoparticle layer comprising contiguous zones alternatingly having electrical conductance and electrical insulation.

22. The device of claim 21 further including a second material filling voids in the nanoparticle layer.

23. A method comprising:

providing a substrate of a first material, the substrate having a first surface;

depositing onto the first surface electrically conductive nanoparticles of a second material;

sintering together the nanoparticles of the second material; and

transmuting the electrical conductance of selected zones of the nanoparticles to electrical insulator by selective oxidation.

24. The method, of claim 23 further including covering the nanoparticle layer and at least portions of the substrate in a third material.

25. The method of claim 23 wherein the nanoparticles are deposited as part of a layer of the second material.

26. A method comprising:

providing a substrate of a first material, the substrate having a first surface;

depositing onto the first surface electrically non-conductive nanoparticles of a second material;

sintering together the nanoparticles of the second material; and

transmuting the electrical non-conductance of selected zones of the nanoparticles to electrical conductance by selective reduction or ablation.

27. The method of claim 26 further including covering the nanoparticle layer and at least portions of the substrate in a third material.

28. The method of claim 26 wherein the nanoparticles are deposited as part of a layer of the second material.