Method for interconnecting components of an electronic system by sintering

Patent metadata

Field	Value
Publication number	US-2022062990-A1
Application number	US-202117446770-A
Country	US
Kind code	A1
Filing date	Sep 2, 2021
Priority date	Sep 3, 2020
Publication date	Mar 3, 2022
Grant date	—

Abstract

Method for interconnecting components of an electronic system, the method comprising the steps of:a) depositing a sintering solution onto a first component in order to form an interconnection layer, the sintering solution comprising a solvent, metal nanoparticles dispersed in the solvent, and a stabilizing agent adsorbed onto the metal nanoparticles.the metal nanoparticles comprising for more than 95.0%, preferably for more than 99.0% of their mass a metal selected from silver, gold, copper and alloys thereof and having a polyhedral shape with an aspect ratio of more than 0.8,b) eliminating, at least partially, the solvent from the interconnection layer such as to form at least one agglomerate in which the stabilizing agent binds them together and maintains at least a portion of the metal nanoparticles at a distance from each other,c) debinding and sintering the interconnection layer by bringing the agglomerate into contact with at least one destabilizing agent configured to desorb the stabilizing agent from the metal nanoparticles in order to aggregate and coalesce said metal nanoparticles between themselves, andd) depositing a second component in contact with the interconnection layer before or during debinding or sintering.

First claim

1 . Method for interconnecting components of an electronic system, the method comprising the steps of:
a) depositing a sintering solution onto a first component in order to form an interconnection layer, the sintering solution comprising a solvent, metal nanoparticles dispersed in the solvent, and a stabilizing agent adsorbed onto the metal nanoparticles, the metal nanoparticles comprising for more than 95.0% of their mass a metal selected from silver, gold, copper and alloys thereof and having a polyhedral shape with an aspect ratio of more than 0.8, b) eliminating, at least partially, the solvent from the interconnection layer such as to form at least one agglomerate in which the stabilizing agent binds them together and maintains at least a portion of the metal nanoparticles at a distance from each other, c) debinding and sintering the interconnection layer by bringing the agglomerate into contact with at least one destabilizing agent configured to desorb the stabilizing agent from the metal nanoparticles in order to aggregate and coalesce said metal nanoparticles between themselves, and d) depositing a second component in contact with the interconnection layer before or during debinding or sintering.

2 . Method according to claim 1 , the metal nanoparticles comprising for more than 99.0% of their mass a metal selected from silver, gold, copper and alloys thereof.

3 . Method according to claim 1 , the solvent being such that its thermal degradation results in the formation of the destabilizing agent.

4 . Method according to claim 1 , more than 99.0% of the mass of the metal nanoparticles being constituted by silver.

5 . Method according to claim 1 , the metal nanoparticles being cubic in shape, optionally truncated.

6 . Method according to claim 1 , the sintering solution comprising, as percentages by weight expressed on the basis of the mass of the sintering solution:
between 20.0% and 90.0% of polyhedral metal nanoparticles, between 0.1% and 3.0% of stabilizing agent, and between 7.0% and 79.9% of solvent.

7 . Method according to claim 1 , the sintering solution comprising a particulate assembly formed from metal microparticles, the smallest microparticles having a size of more than 1 μm, the sintering solution comprising, as percentages by weight expressed on the basis of the mass of the sintering solution:
between 0.1% and 3.0% of stabilizing agent,
between 7.0% and 79.9% of solvent,
between 20.0% and 90.0% of metal nanoparticles and of metal microparticles,

the ratio of the metal microparticles content to the sum of the metal nanoparticles content and metal microparticles content being in the range 0.3 to 0.7.

8 . Method according to claim 1 , the solvent being selected from water, a polyol and mixtures thereof.

9 . Method according to claim 8 , the solvent being a polyol selected from 1,2-propanediol, ethylene glycol, diethylene glycol and mixtures thereof.

10 . Method according to claim 1 , the stabilizing agent being selected from anionic surfactants, amphoteric surfactants, cationic surfactants, non-ionic surfactants and mixtures thereof.

11 . Method according to claim 10 , the stabilizing agent being selected from polyvinylpyrrolidone, polyacrylic acid, sodium tricitrate, and mixtures thereof.

12 . Method according to claim 1 , the destabilizing agent being selected from water, a ketone and mixtures thereof.

13 . Method according to claim 1 , the elimination of solvent in step b) comprising evaporation and/or decomposition of the solvent.

14 . Method according to claim 1 , step b) for eliminating the solvent being carried out at a temperature of less than 200° C.

15 . Method according to claim 1 , step c) for debinding and sintering being carried out at a temperature of less than 200° C.

16 . Method according to claim 15 , sintering being carried out at a temperature of 100° C. or more.

17 . Method according to claim 1 , in which the first component and/or the second component of the electronic system are selected from a support, a chip produced from a semiconductor material, a light emitting diode, a component of an electronic power system.

18 . Sintering solution comprising a solvent, metal nanoparticles dispersed in the solvent, and a stabilizing agent adsorbed onto the metal nanoparticles, the metal nanoparticles comprising for more than 95.0% of their mass a metal selected from silver, gold, copper and alloys thereof and having a polyhedral shape with an aspect ratio of more than 0.8, the sintering solution comprising, as percentages by weight expressed on the basis of the mass of the sintering solution:
between 20.0% and 90.0% of polyhedral metal nanoparticles, between 0.1% and 3.0% of stabilizing agent, and between 7.0% and 79.9% of solvent.

19 . Sintering solution according to claim 18 , the metal nanoparticles comprising for more than 99.0% of their mass a metal selected from silver, gold, copper and alloys thereof.

20 . Sintering solution according to claim 18 , in which more than 95.0% of the mass of the metal nanoparticles is constituted by silver.

21 . Sintering solution according to claim 18 , in which the solvent is selected from water, 1,2-propanediol, ethylene glycol, diethylene glycol and mixtures thereof and the stabilizing agent is selected from anionic surfactants, amphoteric surfactants, cationic surfactants, non-ionic surfactants and mixtures thereof.

Assignees

• Commissariat Energie Atomique

Inventors

• Feautrier Céline
• Bronchy Maxime

Classifications

• H10P95/90

  Thermal treatments, e.g. annealing or sintering · CPC title

• H10W99/00

  Subject matter not provided for in other groups of this subclass · CPC title

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title

• B22F3/15

  Hot isostatic pressing · CPC title

• B22F3/24 Primary

  After-treatment of workpieces or articles {(B22F3/1146 takes precedence)} · CPC title