Sintering paste

Patent metadata

Field	Value
Publication number	US-11162007-B2
Application number	US-201916289789-A
Country	US
Kind code	B2
Filing date	Mar 1, 2019
Priority date	Oct 29, 2012
Publication date	Nov 2, 2021
Grant date	Nov 2, 2021

Abstract

A sintering powder comprising: a particulate having a mean longest diameter of less than 10 microns, wherein at least some of the particles forming the particulate comprise a metal at least partially coated with a capping agent. A sintering paste and sintering film comprising the sintering powder. A method for making a sintered joint by sintering the sintering powder, paste, or film in the vicinity of two or more workpieces.

First claim

The invention claimed is:

1. A sintering paste comprising:
a sintering powder, wherein the sintering powder comprises,
a particulate comprising particles having a mean longest diameter of less than 10 microns, wherein at least some of the particles forming the particulate comprise a metal at least partially coated with a capping agent,
wherein the particulate comprises a first type of particles having a longest diameter of from 1 to 100 nm and a second type of particles having a longest diameter of from greater than 100 nm to 50 microns,
wherein the particulate comprises from 81 to 99 wt % of the first type of particles and from 1 to 19 wt % of the second type of particles;

an organosilver compound in a concentration of 1-25 wt %; and
a solvent.

2. The sintering paste of claim 1 , wherein the organosilver compound comprises one or more of silver oxalate, silver lactate, silver succinate, silver neodecanoate, silver citrate and silver stearate.

3. The sintering paste of claim 1 , further comprising a fatty acid.

4. The sintering paste of claim 1 , further comprising a peroxide.

5. The sintering paste of claim 1 , wherein the paste is resin free.

6. The sintering paste of claim 1 , wherein the paste is pin transferable and/or exhibits a thermal conductivity of greater than 200 W/mK and/or is capable of providing a die shear strength of from 25 to 45 MPa.

7. The sintering paste of claim 1 , wherein the sintering paste is applied in a sintering film.

8. The sintering paste of claim 1 , further comprising at least one of an activator, a rheology modifier, and a surfactant.

9. The sintering paste of claim 1 , wherein the first type of particles and the second type of particles are at least partially coated with the same capping agent.

10. The sintering paste of claim 1 , wherein the particulate of particles comprises 0.1 to 3 wt % capping agent.

11. The sintering paste of claim 10 , wherein the second type of particles does not contain capping agent.

12. The sintering paste of claim 10 , wherein the capping agent is octylamine.

13. The sintering paste of claim 1 comprising 2-10 wt % of the organosilver compound.

14. The sintering paste of claim 1 , further comprising a binder.

15. The sintering paste of claim 14 , wherein the binder comprises an epoxy-based resin.

16. The sintering paste of claim 1 , wherein the solvent comprises at least one of a monoterpene alcohol, a glycol, and glycol ether.

17. The sintering paste of claim 1 comprising at least one of:
i. from 1 to 15 wt % binder;
ii. from 1 to 15 wt % solvent;
iii. up to 1 wt % rheology modifier;
iv. up to 1 wt % activator; and
v. up to 6 wt % surfactant.

18. The sintering paste of claim 1 , wherein the organosilver compound comprises silver oxalate.

19. The sintering paste of claim 1 , wherein the organosilver compound comprises silver lactate.

20. The sintering paste of claim 13 , wherein the organosilver compound comprises silver oxalate.

Assignees

• Alpha Assembly Solutions Inc

Inventors

• Ghosal Shamik
• Pandher Ranjit
• Khaselev Oscar
• Bhatkal Ravi
• Raut Rahul
• Singh Bawa
• De Avila Ribas Morgana
• Sarkar Siuli
• Mukherjee Sutapa
• Kumar Sathish
• Chandran Remya
• Vishwanath Pavan
• Pachamuthu Ashok
• Boureghda Monnir
• Desai Nitin
• Lifton Anna
• Chaki Nirmalya Kumar

Classifications

• B22F1/054

  Nanosized particles · CPC title

• B22F1/052 Primary

  characterised by a mixture of particles of different sizes or by the particle size distribution · CPC title

• B22F1/10

  Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title

• B22F1/103

  containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent · CPC title

• B22F1/102

  Metallic powder coated with organic material · CPC title