Methods of promoting adhesion between underfill and conductive bumps and structures formed thereby

Patent metadata

Field	Value
Publication number	US-10115606-B2
Application number	US-201615139265-A
Country	US
Kind code	B2
Filing date	Apr 26, 2016
Priority date	Dec 20, 2012
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

Methods of forming a microelectronic packaging structure and associated structures formed thereby are described. Those methods and structures may include modifying an underfill material with one of a thiol adhesion promoter, an azole coupling agent, surface modified filler, and peroxide based cross-linking polymer chemistries to greatly enhance adhesion in package structures utilizing the embodiments herein.

First claim

What is claimed is:

1. A method of forming a package structure comprising:
modifying a filler to have a surface comprising a thiol based adhesion promoter; and
subsequent to modifying the filler, adding the modified filler to an underfill material; and
forming the underfill material having the modified filler on conductive bumps of the package structure, wherein the thiol based adhesion promoter comprises a molecular weight above about 150 g/mol.

2. The method of claim 1 further comprising wherein the thiol based adhesion promoter comprises a silane.

3. The method of claim 2 further comprising wherein the silane comprises mercaptosilane, and wherein the mercaptosilane comprises electron withdrawing functional groups that remove electrons from the conductive bumps.

4. The method of claim 1 further comprising wherein the filler material comprises an azole coupling agent.

5. The method of claim 1 further comprising wherein the underfill material further comprises a peroxide cross linking chemistry.

6. The method of claim 1 further comprising wherein the filler is modified with at least one of mercaptosilane and carbonyl groups.

7. The method of claim 5 further comprising wherein the peroxide cross linking chemistry increases the amount of bonding to the conductive bump material.

8. The method of claim 4 further comprising wherein the azole based coupling agent forms coordinative bonds with the conductive bumps.

9. The method of claim 1 further comprising wherein the conductive bumps comprise copper.

10. The method of claim 6 further comprising wherein the underfill material comprises at least one of epoxy, cyanoacrylate, polyurethane, phenolics, and polyolefins, and wherein the filler material is modified with at least one of a benzotriazole, benzotriazole-5-carboxylic acid, imidazole, 8-azadenine, heterocyclic compounds comprising at least one of nitrogen or sulfur, polybenzimidazole, polybenzoxazole (PBO) or polybenzthiazole (PBT).

11. A method of forming a package structure comprising:
modifying a filler to have a surface comprising an azole based coupling agent and
subsequent to modifying the filler, adding the modified filler to an underfill material; and
forming the underfill material on conductive bumps of the package structure.

12. The method of claim 11 further comprising wherein the azole based coupling agent comprises at least one of benzotriazole, benzotriazole-5-carboxylic acid, imidazole, 8-azadenine, heterocyclic compounds comprising at least one of nitrogen or sulfur, polybenzimidazole, polybenzoxazole (PBO) or polybenzthiazole (PBT).

13. The method of claim 12 further comprising wherein the azole coupling agent may comprise precursors of PBO and PBT.

14. The method of claim 12 further comprising wherein the underfill material is cured, and wherein the PBO and PBT are co-cured with the underfill material.

15. The method of claim 11 further comprising wherein the underfill comprises at least one of cyanoacrylate, polyurethane, phenolics, or polyolefins.

16. The method of claim 15 further comprising wherein the filler comprises a thiol group.

17. The method of claim 16 further comprising wherein the filler is modified with at least one of electron withdrawal groups comprising carbonyl groups.

18. The method of claim 11 further comprising wherein the underfill material further comprises peroxide cross linking chemistry.

19. The method of claim 18 further comprising wherein the peroxide cross linking chemistry increases the amount of bonding to the conductive bump material.

20. The method of claim 11 further comprising wherein the azole based coupling agent forms coordinative bonds with the conductive bumps.

21. The method of claim 11 further comprising wherein the azole based coupling agent donates electrons to vacant d orbitals of the conductive bumps.

22. The method of claim 11 further comprising wherein the conductive bumps comprise copper.

23. The method of claim 11 further comprising wherein the conductive bumps couple the package structure to a device.

Assignees

• Intel Corp

Inventors

• Bai Yiqun
• Wei Yuying
• Krishnan Arjun
• Ramalingam Suriyakala
• Xiu Yonghao
• Canham Beverly J
• Nagarajan Sivakumar
• Jayaraman Saikumar
• Ananthakrishnan Nisha

Classifications

• H10W74/15

  on active surfaces of flip-chip devices, e.g. underfills · CPC title

• H10W90/734

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W90/724

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W72/355

  of outermost layers of multilayered die-attach connectors, e.g. material of a coating · CPC title

• H10W72/352

  comprising metals or metalloids, e.g. solders · CPC title