Copper paste for pressureless bonding, bonded body and semiconductor device

Patent metadata

Field	Value
Publication number	US-10930612-B2
Application number	US-201716476969-A
Country	US
Kind code	B2
Filing date	Jan 11, 2017
Priority date	Jan 11, 2017
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

A copper paste for pressureless bonding is a copper paste for pressureless bonding, containing: metal particles; and a dispersion medium, in which the metal particles include sub-micro copper particles having a volume average particle diameter of greater than or equal to 0.01 μm and less than or equal to 0.8 μm, and micro copper particles having a volume average particle diameter of greater than or equal to 2.0 μm and less than or equal to 50 μm, and the dispersion medium contains a solvent having a boiling point of higher than or equal to 300° C., and a content of the solvent having a boiling point of higher than or equal to 300° C. is greater than or equal to 2 mass % on the basis of a total mass of the copper paste for pressureless bonding.

First claim

The invention claimed is:

1. A copper paste for pressureless bonding, containing:
metal particles; and
a dispersion medium,
wherein the metal particles include sub-micro copper particles having a volume average particle diameter of greater than or equal to 0.01 μm and less than or equal to 0.8 μm, and micro copper particles having a volume average particle diameter of greater than or equal to 2.0 μm and less than or equal to 50 μm,
the dispersion medium contains a solvent having a boiling point of higher than or equal to 300° C., and a content of the solvent having a boiling point of higher than or equal to 300° C. is greater than or equal to 2 mass % on the basis of a total mass of the copper paste for pressureless bonding, and
when the copper paste for pressureless bonding that exists between two members is heated at a temperature of higher than or equal to 250° C. and lower than 350° C., the micro copper particles and the sub-micro copper particles are sintered, metal bonding is formed, and the two members are bonded together at a die shear strength of greater than or equal to 10 MPa and a thermal conductivity of greater than or equal to 100 W/(m·K).

2. The copper paste for pressureless bonding according to claim 1 ,
wherein the solvent having a boiling point of higher than or equal to 300° C. has at least one type of group selected from the group consisting of a hydroxy group, an ether group, and an ester group.

3. The copper paste for pressureless bonding according to claim 1 ,
wherein the content of the solvent having a boiling point of higher than or equal to 300° C. that remains when a temperature rises to 300° C. from 25° C. is greater than or equal to 1 mass % on the basis of a mass of the copper paste for pressureless bonding when a temperature rises to 300° C.

4. A bonded body, comprising:
a first member;
a second member having a thermal expansion rate different from that of the first member; and
a sintered body of the copper paste for pressureless bonding according to claim 1 , the sintered body bonding the first member and the second member together.

5. A manufacturing method of a bonded body, comprising:
a step of preparing a laminated body in which a first member, the copper paste for pressureless bonding according to claim 1 , and a second member having a thermal expansion rate different from that of the first member are laminated in this order in a direction side in which self-weight of the first member acts, and of sintering the copper paste for pressureless bonding in a state of receiving the self-weight of the first member, or the self-weight of the first member and a pressure of less than or equal to 0.01 MPa.

6. A semiconductor device, comprising:
a first member;
a second member having a thermal expansion rate different from that of the first member; and
a sintered body of the copper paste for pressureless bonding according to claim 1 , the sintered body bonding the first member and the second member together,
wherein at least one of the first member and the second member is a semiconductor element.

7. A copper paste for pressureless bonding, containing:
metal particles; and
a dispersion medium,
wherein the metal particles include sub-micro copper particles having a volume average particle diameter of greater than or equal to 0.01 μm and less than or equal to 0.8 μm, and micro copper particles having a volume average particle diameter of greater than or equal to 2.0 μm and less than or equal to 50 μm,
the dispersion medium contains a solvent having a boiling point of higher than or equal to 300° C., and a content of the solvent having a boiling point of higher than or equal to 300° C. is greater than or equal to 8 volume % on the basis of a total volume of the copper paste for pressureless bonding, and
when the copper paste for pressureless bonding that exists between two members is heated at a temperature of higher than or equal to 250° C. and lower than 350° C., the micro copper particles and the sub-micro copper particles are sintered, metal bonding is formed, and the two members are bonded together at a die shear strength of greater than or equal to 10 MPa and a thermal conductivity of greater than or equal to 100 W/(m·K).

8. The copper paste for pressureless bonding according to claim 7 ,
wherein the solvent having a boiling point of higher than or equal to 300° C. has at least one type of group selected from the group consisting of a hydroxy group, an ether group, and an ester group.

9. The copper paste for pressureless bonding according to claim 7 ,
wherein the content of the solvent having a boiling point of higher than or equal to 300° C. that remains when a temperature rises to 300° C. from 25° C. is greater than or equal to 1 mass % on the basis of a mass of the copper paste for pressureless bonding when a temperature rises to 300° C.

Assignees

• Hitachi Chemical Co Ltd
• Showa Denko Materials Co Ltd

Inventors

• Nakako Hideo
• Kurafuchi Kazuhiko
• Ejiri Yoshinori
• Ishikawa Dai
• Sugama Chie
• Kawana Yuki

Classifications

• H10W72/07331

  Connecting techniques · CPC title

• H10W72/352

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

• H10W72/325

  Die-attach connectors having a filler embedded in a matrix · CPC title

• H10W72/551

  Materials of bond wires · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title